Merge tag 'tty-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver patches from Greg KH:
"Here's the big tty/serial driver update for 3.20-rc1. Nothing huge
here, just lots of driver updates and some core tty layer fixes as
well. All have been in linux-next with no reported issues"

* tag 'tty-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (119 commits)
serial: 8250: Fix UART_BUG_TXEN workaround
serial: driver for ETRAX FS UART
tty: remove unused variable sprop
serial: of-serial: fetch line number from DT
serial: samsung: earlycon support depends on CONFIG_SERIAL_SAMSUNG_CONSOLE
tty/serial: serial8250_set_divisor() can be static
tty/serial: Add Spreadtrum sc9836-uart driver support
Documentation: DT: Add bindings for Spreadtrum SoC Platform
serial: samsung: remove redundant interrupt enabling
tty: Remove external interface for tty_set_termios()
serial: omap: Fix RTS handling
serial: 8250_omap: Use UPSTAT_AUTORTS for RTS handling
serial: core: Rework hw-assisted flow control support
tty/serial: 8250_early: Add support for PXA UARTs
tty/serial: of_serial: add support for PXA/MMP uarts
tty/serial: of_serial: add DT alias ID handling
serial: 8250: Prevent concurrent updates to shadow registers
serial: 8250: Use canary to restart console after suspend
serial: 8250: Refactor XR17V35X divisor calculation
serial: 8250: Refactor divisor programming
...

Documentation/devicetree/bindings/arm/sprd.txt

···
+Spreadtrum SoC Platforms Device Tree Bindings
+----------------------------------------------------
+
+Sharkl64 is a Spreadtrum's SoC Platform which is based
+on ARM 64-bit processor.
+
+SC9836 openphone board with SC9836 SoC based on the
+Sharkl64 Platform shall have the following properties.
+
+Required root node properties:
+        - compatible = "sprd,sc9836-openphone", "sprd,sc9836";

Documentation/devicetree/bindings/serial/digicolor-usart.txt

···
+Binding for Conexant Digicolor USART
+
+Note: this binding is only applicable for using the USART peripheral as
+UART. USART also support synchronous serial protocols like SPI and I2S. Use
+the binding that matches the wiring of your system.
+
+Required properties:
+- compatible : should be "cnxt,cx92755-usart".
+- reg: Should contain USART controller registers location and length.
+- interrupts: Should contain a single USART controller interrupt.
+- clocks: Must contain phandles to the USART clock
+  See ../clocks/clock-bindings.txt for details.
+
+Note: Each UART port should have an alias correctly numbered
+in "aliases" node.
+
+Example:
+	aliases {
+		serial0 = &uart0;
+	};
+
+	uart0: uart@f0000740 {
+		compatible = "cnxt,cx92755-usart";
+		reg = <0xf0000740 0x20>;
+		clocks = <&main_clk>;
+		interrupts = <44>;
+	};

Documentation/devicetree/bindings/serial/sirf-uart.txt

···
 
 Required properties:
 - compatible : Should be "sirf,prima2-uart", "sirf, prima2-usp-uart",
-		"sirf,marco-uart" or "sirf,marco-bt-uart" which means
+		"sirf,atlas7-uart" or "sirf,atlas7-bt-uart" which means
 		uart located in BT module and used for BT.
 - reg : Offset and length of the register set for the device
 - interrupts : Should contain uart interrupt
···
 for uart use in BT module,
 uart6: uart@11000000 {
 	cell-index = <6>;
-	compatible = "sirf,marco-bt-uart", "sirf,marco-uart";
+	compatible = "sirf,atlas7-bt-uart", "sirf,atlas7-uart";
 	reg = <0x11000000 0x1000>;
 	interrupts = <0 100 0>;
 	clocks = <&clks 138>, <&clks 140>, <&clks 141>;

Documentation/devicetree/bindings/serial/sprd-uart.txt

···
+* Spreadtrum serial UART
+
+Required properties:
+- compatible: must be "sprd,sc9836-uart"
+- reg: offset and length of the register set for the device
+- interrupts: exactly one interrupt specifier
+- clocks: phandles to input clocks.

Documentation/devicetree/bindings/vendor-prefixes.txt

···
 chunghwa	Chunghwa Picture Tubes Ltd.
 cirrus	Cirrus Logic, Inc.
 cnm	Chips&Media, Inc.
+cnxt	Conexant Systems, Inc.
 cortina	Cortina Systems, Inc.
 cosmic	Cosmic Circuits
 crystalfontz	Crystalfontz America, Inc.
···
 solidrun	SolidRun
 sony	Sony Corporation
 spansion	Spansion Inc.
+sprd	Spreadtrum Communications Inc.
 st	STMicroelectronics
 ste	ST-Ericsson
 stericsson	ST-Ericsson

Documentation/kernel-parameters.txt

···
 
 		smh	Use ARM semihosting calls for early console.
 
+		s3c2410,<addr>
+		s3c2412,<addr>
+		s3c2440,<addr>
+		s3c6400,<addr>
+		s5pv210,<addr>
+		exynos4210,<addr>
+			Use early console provided by serial driver available
+			on Samsung SoCs, requires selecting proper type and
+			a correct base address of the selected UART port. The
+			serial port must already be setup and configured.
+			Options are not yet supported.
+
 	earlyprintk=	[X86,SH,BLACKFIN,ARM,M68k]
 			earlyprintk=vga
 			earlyprintk=efi

arch/arm/boot/dts/exynos4210-origen.dts

···
 
 	chosen {
 		bootargs ="root=/dev/ram0 rw ramdisk=8192 initrd=0x41000000,8M console=ttySAC2,115200 init=/linuxrc";
+		stdout-path = &serial_2;
 	};
 
 	regulators {

arch/arm/boot/dts/exynos4210-smdkv310.dts

···
 
 	chosen {
 		bootargs = "root=/dev/ram0 rw ramdisk=8192 initrd=0x41000000,8M console=ttySAC1,115200 init=/linuxrc";
+		stdout-path = &serial_1;
 	};
 
 	sdhci@12530000 {

arch/arm/boot/dts/exynos4210-trats.dts

···
 
 	chosen {
 		bootargs = "console=ttySAC2,115200N8 root=/dev/mmcblk0p5 rootwait earlyprintk panic=5";
+		stdout-path = &serial_2;
 	};
 
 	regulators {

arch/arm/boot/dts/exynos4210-universal_c210.dts

···
 
 	chosen {
 		bootargs = "console=ttySAC2,115200N8 root=/dev/mmcblk0p5 rw rootwait earlyprintk panic=5 maxcpus=1";
+		stdout-path = &serial_2;
 	};
 
 	sysram@02020000 {

arch/arm/boot/dts/exynos4412-odroid-common.dtsi

···
 #include "exynos4412.dtsi"
 
 / {
+	chosen {
+		stdout-path = &serial_1;
+	};
+
 	firmware@0204F000 {
 		compatible = "samsung,secure-firmware";
 		reg = <0x0204F000 0x1000>;

arch/arm/boot/dts/exynos4412-origen.dts

···
 
 	chosen {
 		bootargs ="console=ttySAC2,115200";
+		stdout-path = &serial_2;
 	};
 
 	firmware@0203F000 {

arch/arm/boot/dts/exynos4412-smdk4412.dts

···
 
 	chosen {
 		bootargs ="root=/dev/ram0 rw ramdisk=8192 initrd=0x41000000,8M console=ttySAC1,115200 init=/linuxrc";
+		stdout-path = &serial_1;
 	};
 
 	g2d@10800000 {

arch/arm/boot/dts/exynos4412-tiny4412.dts

···
 	model = "FriendlyARM TINY4412 board based on Exynos4412";
 	compatible = "friendlyarm,tiny4412", "samsung,exynos4412", "samsung,exynos4";
 
+	chosen {
+		stdout-path = &serial_0;
+	};
+
 	memory {
 		reg = <0x40000000 0x40000000>;
 	};

arch/arm/boot/dts/exynos4412-trats2.dts

···
 
 	chosen {
 		bootargs = "console=ttySAC2,115200N8 root=/dev/mmcblk0p5 rootwait earlyprintk panic=5";
+		stdout-path = &serial_2;
 	};
 
 	firmware@0204F000 {

arch/x86/include/asm/intel-mid.h

···
 #define SFI_MTMR_MAX_NUM 8
 #define SFI_MRTC_MAX	8
 
-extern struct console early_mrst_console;
-extern void mrst_early_console_init(void);
-
 extern struct console early_hsu_console;
 extern void hsu_early_console_init(const char *);
 

arch/x86/kernel/early_printk.c

···
 #include <linux/usb/ehci_def.h>
 #include <linux/efi.h>
 #include <asm/efi.h>
+#include <asm/pci_x86.h>
 
 /* Simple VGA output */
 #define VGABASE		(__ISA_IO_base + 0xb8000)
···
 
 /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
 
-static int early_serial_base = 0x3f8;  /* ttyS0 */
+static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
 
 #define XMTRDY          0x20
 
···
 #define DLL             0       /*  Divisor Latch Low         */
 #define DLH             1       /*  Divisor latch High        */
 
+static void mem32_serial_out(unsigned long addr, int offset, int value)
+{
+	uint32_t *vaddr = (uint32_t *)addr;
+	/* shift implied by pointer type */
+	writel(value, vaddr + offset);
+}
+
+static unsigned int mem32_serial_in(unsigned long addr, int offset)
+{
+	uint32_t *vaddr = (uint32_t *)addr;
+	/* shift implied by pointer type */
+	return readl(vaddr + offset);
+}
+
+static unsigned int io_serial_in(unsigned long addr, int offset)
+{
+	return inb(addr + offset);
+}
+
+static void io_serial_out(unsigned long addr, int offset, int value)
+{
+	outb(value, addr + offset);
+}
+
+static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
+static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
+
 static int early_serial_putc(unsigned char ch)
 {
 	unsigned timeout = 0xffff;
 
-	while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout)
+	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
 		cpu_relax();
-	outb(ch, early_serial_base + TXR);
+	serial_out(early_serial_base, TXR, ch);
 	return timeout ? 0 : -1;
 }
 
···
 	}
 }
 
+static __init void early_serial_hw_init(unsigned divisor)
+{
+	unsigned char c;
+
+	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
+	serial_out(early_serial_base, IER, 0);	/* no interrupt */
+	serial_out(early_serial_base, FCR, 0);	/* no fifo */
+	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */
+
+	c = serial_in(early_serial_base, LCR);
+	serial_out(early_serial_base, LCR, c | DLAB);
+	serial_out(early_serial_base, DLL, divisor & 0xff);
+	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
+	serial_out(early_serial_base, LCR, c & ~DLAB);
+}
+
 #define DEFAULT_BAUD 9600
 
 static __init void early_serial_init(char *s)
 {
-	unsigned char c;
 	unsigned divisor;
-	unsigned baud = DEFAULT_BAUD;
+	unsigned long baud = DEFAULT_BAUD;
 	char *e;
 
 	if (*s == ',')
···
 			s++;
 	}
 
-	outb(0x3, early_serial_base + LCR);	/* 8n1 */
-	outb(0, early_serial_base + IER);	/* no interrupt */
-	outb(0, early_serial_base + FCR);	/* no fifo */
-	outb(0x3, early_serial_base + MCR);	/* DTR + RTS */
-
 	if (*s) {
-		baud = simple_strtoul(s, &e, 0);
-		if (baud == 0 || s == e)
+		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
 			baud = DEFAULT_BAUD;
 	}
 
+	/* Convert from baud to divisor value */
 	divisor = 115200 / baud;
-	c = inb(early_serial_base + LCR);
-	outb(c | DLAB, early_serial_base + LCR);
-	outb(divisor & 0xff, early_serial_base + DLL);
-	outb((divisor >> 8) & 0xff, early_serial_base + DLH);
-	outb(c & ~DLAB, early_serial_base + LCR);
+
+	/* These will always be IO based ports */
+	serial_in = io_serial_in;
+	serial_out = io_serial_out;
+
+	/* Set up the HW */
+	early_serial_hw_init(divisor);
 }
+
+#ifdef CONFIG_PCI
+/*
+ * early_pci_serial_init()
+ *
+ * This function is invoked when the early_printk param starts with "pciserial"
+ * The rest of the param should be ",B:D.F,baud" where B, D & F describe the
+ * location of a PCI device that must be a UART device.
+ */
+static __init void early_pci_serial_init(char *s)
+{
+	unsigned divisor;
+	unsigned long baud = DEFAULT_BAUD;
+	u8 bus, slot, func;
+	uint32_t classcode, bar0;
+	uint16_t cmdreg;
+	char *e;
+
+
+	/*
+	 * First, part the param to get the BDF values
+	 */
+	if (*s == ',')
+		++s;
+
+	if (*s == 0)
+		return;
+
+	bus = (u8)simple_strtoul(s, &e, 16);
+	s = e;
+	if (*s != ':')
+		return;
+	++s;
+	slot = (u8)simple_strtoul(s, &e, 16);
+	s = e;
+	if (*s != '.')
+		return;
+	++s;
+	func = (u8)simple_strtoul(s, &e, 16);
+	s = e;
+
+	/* A baud might be following */
+	if (*s == ',')
+		s++;
+
+	/*
+	 * Second, find the device from the BDF
+	 */
+	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
+	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
+	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
+
+	/*
+	 * Verify it is a UART type device
+	 */
+	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
+	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
+	   (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */
+		return;
+
+	/*
+	 * Determine if it is IO or memory mapped
+	 */
+	if (bar0 & 0x01) {
+		/* it is IO mapped */
+		serial_in = io_serial_in;
+		serial_out = io_serial_out;
+		early_serial_base = bar0&0xfffffffc;
+		write_pci_config(bus, slot, func, PCI_COMMAND,
+						cmdreg|PCI_COMMAND_IO);
+	} else {
+		/* It is memory mapped - assume 32-bit alignment */
+		serial_in = mem32_serial_in;
+		serial_out = mem32_serial_out;
+		/* WARNING! assuming the address is always in the first 4G */
+		early_serial_base =
+			(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
+		write_pci_config(bus, slot, func, PCI_COMMAND,
+						cmdreg|PCI_COMMAND_MEMORY);
+	}
+
+	/*
+	 * Lastly, initalize the hardware
+	 */
+	if (*s) {
+		if (strcmp(s, "nocfg") == 0)
+			/* Sometimes, we want to leave the UART alone
+			 * and assume the BIOS has set it up correctly.
+			 * "nocfg" tells us this is the case, and we
+			 * should do no more setup.
+			 */
+			return;
+		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
+			baud = DEFAULT_BAUD;
+	}
+
+	/* Convert from baud to divisor value */
+	divisor = 115200 / baud;
+
+	/* Set up the HW */
+	early_serial_hw_init(divisor);
+}
+#endif
 
 static struct console early_serial_console = {
 	.name =		"earlyser",
···
 			early_serial_init(buf + 4);
 			early_console_register(&early_serial_console, keep);
 		}
+#ifdef CONFIG_PCI
+		if (!strncmp(buf, "pciserial", 9)) {
+			early_pci_serial_init(buf + 9);
+			early_console_register(&early_serial_console, keep);
+			buf += 9; /* Keep from match the above "serial" */
+		}
+#endif
 		if (!strncmp(buf, "vga", 3) &&
 		    boot_params.screen_info.orig_video_isVGA == 1) {
 			max_xpos = boot_params.screen_info.orig_video_cols;
···
 			early_console_register(&xenboot_console, keep);
 #endif
 #ifdef CONFIG_EARLY_PRINTK_INTEL_MID
-		if (!strncmp(buf, "mrst", 4)) {
-			mrst_early_console_init();
-			early_console_register(&early_mrst_console, keep);
-		}
-
 		if (!strncmp(buf, "hsu", 3)) {
 			hsu_early_console_init(buf + 3);
 			early_console_register(&early_hsu_console, keep);

arch/x86/platform/intel-mid/device_libs/Makefile

···
 obj-$(subst m,y,$(CONFIG_INPUT_BMA150)) += platform_bma023.o
 obj-$(subst m,y,$(CONFIG_GPIO_PCA953X)) += platform_tca6416.o
 obj-$(subst m,y,$(CONFIG_DRM_MEDFIELD)) += platform_tc35876x.o
-# SPI Devices
-obj-$(subst m,y,$(CONFIG_SERIAL_MRST_MAX3110)) += platform_max3111.o
 # MISC Devices
 obj-$(subst m,y,$(CONFIG_KEYBOARD_GPIO)) += platform_gpio_keys.o
 obj-$(subst m,y,$(CONFIG_INTEL_MID_WATCHDOG)) += platform_wdt.o

arch/x86/platform/intel-mid/device_libs/platform_max3111.c

···
-/*
- * platform_max3111.c: max3111 platform data initilization file
- *
- * (C) Copyright 2013 Intel Corporation
- * Author: Sathyanarayanan Kuppuswamy <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
- */
-
-#include <linux/gpio.h>
-#include <linux/spi/spi.h>
-#include <asm/intel-mid.h>
-
-static void __init *max3111_platform_data(void *info)
-{
-	struct spi_board_info *spi_info = info;
-	int intr = get_gpio_by_name("max3111_int");
-
-	spi_info->mode = SPI_MODE_0;
-	if (intr == -1)
-		return NULL;
-	spi_info->irq = intr + INTEL_MID_IRQ_OFFSET;
-	return NULL;
-}
-
-static const struct devs_id max3111_dev_id __initconst = {
-	.name = "spi_max3111",
-	.type = SFI_DEV_TYPE_SPI,
-	.get_platform_data = &max3111_platform_data,
-};
-
-sfi_device(max3111_dev_id);

arch/x86/platform/intel-mid/early_printk_intel_mid.c

···
  */
 
 /*
- * This file implements two early consoles named mrst and hsu.
- * mrst is based on Maxim3110 spi-uart device, it exists in both
- * Moorestown and Medfield platforms, while hsu is based on a High
- * Speed UART device which only exists in the Medfield platform
+ * This file implements early console named hsu.
+ * hsu is based on a High Speed UART device which only exists in the Medfield
+ * platform
  */
 
 #include <linux/serial_reg.h>
 #include <linux/serial_mfd.h>
-#include <linux/kmsg_dump.h>
 #include <linux/console.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
···
 #include <asm/fixmap.h>
 #include <asm/pgtable.h>
 #include <asm/intel-mid.h>
-
-#define MRST_SPI_TIMEOUT		0x200000
-#define MRST_REGBASE_SPI0		0xff128000
-#define MRST_REGBASE_SPI1		0xff128400
-#define MRST_CLK_SPI0_REG		0xff11d86c
-
-/* Bit fields in CTRLR0 */
-#define SPI_DFS_OFFSET			0
-
-#define SPI_FRF_OFFSET			4
-#define SPI_FRF_SPI			0x0
-#define SPI_FRF_SSP			0x1
-#define SPI_FRF_MICROWIRE		0x2
-#define SPI_FRF_RESV			0x3
-
-#define SPI_MODE_OFFSET			6
-#define SPI_SCPH_OFFSET			6
-#define SPI_SCOL_OFFSET			7
-#define SPI_TMOD_OFFSET			8
-#define	SPI_TMOD_TR			0x0		/* xmit & recv */
-#define SPI_TMOD_TO			0x1		/* xmit only */
-#define SPI_TMOD_RO			0x2		/* recv only */
-#define SPI_TMOD_EPROMREAD		0x3		/* eeprom read mode */
-
-#define SPI_SLVOE_OFFSET		10
-#define SPI_SRL_OFFSET			11
-#define SPI_CFS_OFFSET			12
-
-/* Bit fields in SR, 7 bits */
-#define SR_MASK				0x7f		/* cover 7 bits */
-#define SR_BUSY				(1 << 0)
-#define SR_TF_NOT_FULL			(1 << 1)
-#define SR_TF_EMPT			(1 << 2)
-#define SR_RF_NOT_EMPT			(1 << 3)
-#define SR_RF_FULL			(1 << 4)
-#define SR_TX_ERR			(1 << 5)
-#define SR_DCOL				(1 << 6)
-
-struct dw_spi_reg {
-	u32	ctrl0;
-	u32	ctrl1;
-	u32	ssienr;
-	u32	mwcr;
-	u32	ser;
-	u32	baudr;
-	u32	txfltr;
-	u32	rxfltr;
-	u32	txflr;
-	u32	rxflr;
-	u32	sr;
-	u32	imr;
-	u32	isr;
-	u32	risr;
-	u32	txoicr;
-	u32	rxoicr;
-	u32	rxuicr;
-	u32	msticr;
-	u32	icr;
-	u32	dmacr;
-	u32	dmatdlr;
-	u32	dmardlr;
-	u32	idr;
-	u32	version;
-
-	/* Currently operates as 32 bits, though only the low 16 bits matter */
-	u32	dr;
-} __packed;
-
-#define dw_readl(dw, name)		__raw_readl(&(dw)->name)
-#define dw_writel(dw, name, val)	__raw_writel((val), &(dw)->name)
-
-/* Default use SPI0 register for mrst, we will detect Penwell and use SPI1 */
-static unsigned long mrst_spi_paddr = MRST_REGBASE_SPI0;
-
-static u32 *pclk_spi0;
-/* Always contains an accessible address, start with 0 */
-static struct dw_spi_reg *pspi;
-
-static struct kmsg_dumper dw_dumper;
-static int dumper_registered;
-
-static void dw_kmsg_dump(struct kmsg_dumper *dumper,
-			 enum kmsg_dump_reason reason)
-{
-	static char line[1024];
-	size_t len;
-
-	/* When run to this, we'd better re-init the HW */
-	mrst_early_console_init();
-
-	while (kmsg_dump_get_line(dumper, true, line, sizeof(line), &len))
-		early_mrst_console.write(&early_mrst_console, line, len);
-}
-
-/* Set the ratio rate to 115200, 8n1, IRQ disabled */
-static void max3110_write_config(void)
-{
-	u16 config;
-
-	config = 0xc001;
-	dw_writel(pspi, dr, config);
-}
-
-/* Translate char to a eligible word and send to max3110 */
-static void max3110_write_data(char c)
-{
-	u16 data;
-
-	data = 0x8000 | c;
-	dw_writel(pspi, dr, data);
-}
-
-void mrst_early_console_init(void)
-{
-	u32 ctrlr0 = 0;
-	u32 spi0_cdiv;
-	u32 freq; /* Freqency info only need be searched once */
-
-	/* Base clk is 100 MHz, the actual clk = 100M / (clk_divider + 1) */
-	pclk_spi0 = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
-							MRST_CLK_SPI0_REG);
-	spi0_cdiv = ((*pclk_spi0) & 0xe00) >> 9;
-	freq = 100000000 / (spi0_cdiv + 1);
-
-	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_PENWELL)
-		mrst_spi_paddr = MRST_REGBASE_SPI1;
-
-	pspi = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
-						mrst_spi_paddr);
-
-	/* Disable SPI controller */
-	dw_writel(pspi, ssienr, 0);
-
-	/* Set control param, 8 bits, transmit only mode */
-	ctrlr0 = dw_readl(pspi, ctrl0);
-
-	ctrlr0 &= 0xfcc0;
-	ctrlr0 |= 0xf | (SPI_FRF_SPI << SPI_FRF_OFFSET)
-		      | (SPI_TMOD_TO << SPI_TMOD_OFFSET);
-	dw_writel(pspi, ctrl0, ctrlr0);
-
-	/*
-	 * Change the spi0 clk to comply with 115200 bps, use 100000 to
-	 * calculate the clk dividor to make the clock a little slower
-	 * than real baud rate.
-	 */
-	dw_writel(pspi, baudr, freq/100000);
-
-	/* Disable all INT for early phase */
-	dw_writel(pspi, imr, 0x0);
-
-	/* Set the cs to spi-uart */
-	dw_writel(pspi, ser, 0x2);
-
-	/* Enable the HW, the last step for HW init */
-	dw_writel(pspi, ssienr, 0x1);
-
-	/* Set the default configuration */
-	max3110_write_config();
-
-	/* Register the kmsg dumper */
-	if (!dumper_registered) {
-		dw_dumper.dump = dw_kmsg_dump;
-		kmsg_dump_register(&dw_dumper);
-		dumper_registered = 1;
-	}
-}
-
-/* Slave select should be called in the read/write function */
-static void early_mrst_spi_putc(char c)
-{
-	unsigned int timeout;
-	u32 sr;
-
-	timeout = MRST_SPI_TIMEOUT;
-	/* Early putc needs to make sure the TX FIFO is not full */
-	while (--timeout) {
-		sr = dw_readl(pspi, sr);
-		if (!(sr & SR_TF_NOT_FULL))
-			cpu_relax();
-		else
-			break;
-	}
-
-	if (!timeout)
-		pr_warn("MRST earlycon: timed out\n");
-	else
-		max3110_write_data(c);
-}
-
-/* Early SPI only uses polling mode */
-static void early_mrst_spi_write(struct console *con, const char *str,
-					unsigned n)
-{
-	int i;
-
-	for (i = 0; i < n && *str; i++) {
-		if (*str == '\n')
-			early_mrst_spi_putc('\r');
-		early_mrst_spi_putc(*str);
-		str++;
-	}
-}
-
-struct console early_mrst_console = {
-	.name =		"earlymrst",
-	.write =	early_mrst_spi_write,
-	.flags =	CON_PRINTBUFFER,
-	.index =	-1,
-};
 
 /*
  * Following is the early console based on Medfield HSU (High
···
 		port = clamp_val(port, 0, 2);
 
 	paddr = HSU_PORT_BASE + port * 0x80;
-	phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE, paddr);
+	phsu = (void __iomem *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE, paddr);
 
 	/* Disable FIFO */
 	writeb(0x0, phsu + UART_FCR);

drivers/bluetooth/hci_ath.c

···
 
 static int ath_wakeup_ar3k(struct tty_struct *tty)
 {
-	struct ktermios ktermios;
 	int status = tty->driver->ops->tiocmget(tty);
 
 	if (status & TIOCM_CTS)
 		return status;
 
-	/* Disable Automatic RTSCTS */
-	ktermios = tty->termios;
-	ktermios.c_cflag &= ~CRTSCTS;
-	tty_set_termios(tty, &ktermios);
-
 	/* Clear RTS first */
-	status = tty->driver->ops->tiocmget(tty);
+	tty->driver->ops->tiocmget(tty);
 	tty->driver->ops->tiocmset(tty, 0x00, TIOCM_RTS);
 	mdelay(20);
 
 	/* Set RTS, wake up board */
-	status = tty->driver->ops->tiocmget(tty);
+	tty->driver->ops->tiocmget(tty);
 	tty->driver->ops->tiocmset(tty, TIOCM_RTS, 0x00);
 	mdelay(20);
 
 	status = tty->driver->ops->tiocmget(tty);
-
-	/* Enable Automatic RTSCTS */
-	ktermios.c_cflag |= CRTSCTS;
-	status = tty_set_termios(tty, &ktermios);
-
 	return status;
 }
 

drivers/pnp/driver.c

···
 			return error;
 	}
 
-	if (pnp_dev->protocol->suspend)
+	if (pnp_can_suspend(pnp_dev))
 		pnp_dev->protocol->suspend(pnp_dev, state);
 	return 0;
 }

drivers/tty/amiserial.c

···
 	struct serial_state *info = tty->driver_data;
         unsigned long flags;
 
-	if (serial_paranoia_check(info, tty->name, "rs_send_char"))
+	if (serial_paranoia_check(info, tty->name, "rs_send_xchar"))
 		return;
 
 	info->x_char = ch;

drivers/tty/ehv_bytechan.c

···
 static int find_console_handle(void)
 {
 	struct device_node *np = of_stdout;
-	const char *sprop = NULL;
 	const uint32_t *iprop;
 
 	/* We don't care what the aliased node is actually called.  We only

drivers/tty/isicom.c

···
 
 	outw(0x8000 | ((port->channel) << (card->shift_count)) | 0x3, base);
 	outw((length & 0xff) << 8 | 0x00, base);
-	outw((length & 0xff00), base);
+	outw((length & 0xff00u), base);
 	InterruptTheCard(base);
 
 	unlock_card(card);

drivers/tty/n_tty.c

···
 struct n_tty_data {
 	/* producer-published */
 	size_t read_head;
+	size_t commit_head;
 	size_t canon_head;
 	size_t echo_head;
 	size_t echo_commit;
···
 	return put_user(x, ptr);
 }
 
-static int receive_room(struct tty_struct *tty)
-{
-	struct n_tty_data *ldata = tty->disc_data;
-	int left;
-
-	if (I_PARMRK(tty)) {
-		/* Multiply read_cnt by 3, since each byte might take up to
-		 * three times as many spaces when PARMRK is set (depending on
-		 * its flags, e.g. parity error). */
-		left = N_TTY_BUF_SIZE - read_cnt(ldata) * 3 - 1;
-	} else
-		left = N_TTY_BUF_SIZE - read_cnt(ldata) - 1;
-
-	/*
-	 * If we are doing input canonicalization, and there are no
-	 * pending newlines, let characters through without limit, so
-	 * that erase characters will be handled.  Other excess
-	 * characters will be beeped.
-	 */
-	if (left <= 0)
-		left = ldata->icanon && ldata->canon_head == ldata->read_tail;
-
-	return left;
-}
-
 /**
- *	n_tty_set_room	-	receive space
+ *	n_tty_kick_worker - start input worker (if required)
  *	@tty: terminal
  *
- *	Re-schedules the flip buffer work if space just became available.
+ *	Re-schedules the flip buffer work if it may have stopped
  *
  *	Caller holds exclusive termios_rwsem
  *	   or
···
  *		holds non-exclusive termios_rwsem
  */
 
-static void n_tty_set_room(struct tty_struct *tty)
+static void n_tty_kick_worker(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
-	/* Did this open up the receive buffer? We may need to flip */
-	if (unlikely(ldata->no_room) && receive_room(tty)) {
+	/* Did the input worker stop? Restart it */
+	if (unlikely(ldata->no_room)) {
 		ldata->no_room = 0;
 
 		WARN_RATELIMIT(tty->port->itty == NULL,
···
 	ssize_t n = 0;
 
 	if (!ldata->icanon)
-		n = read_cnt(ldata);
+		n = ldata->commit_head - ldata->read_tail;
 	else
 		n = ldata->canon_head - ldata->read_tail;
 	return n;
···
 
 static void n_tty_check_throttle(struct tty_struct *tty)
 {
-	if (tty->driver->type == TTY_DRIVER_TYPE_PTY)
-		return;
+	struct n_tty_data *ldata = tty->disc_data;
+
 	/*
 	 * Check the remaining room for the input canonicalization
 	 * mode.  We don't want to throttle the driver if we're in
 	 * canonical mode and don't have a newline yet!
 	 */
+	if (ldata->icanon && ldata->canon_head == ldata->read_tail)
+		return;
+
 	while (1) {
 		int throttled;
 		tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
-		if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE)
+		if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE)
 			break;
 		throttled = tty_throttle_safe(tty);
 		if (!throttled)
···
 			return;
 		if (!tty->count)
 			return;
-		n_tty_set_room(tty);
+		n_tty_kick_worker(tty);
 		n_tty_write_wakeup(tty->link);
 		if (waitqueue_active(&tty->link->write_wait))
 			wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT);
···
 			break;
 		if (!tty->count)
 			break;
-		n_tty_set_room(tty);
+		n_tty_kick_worker(tty);
 		unthrottled = tty_unthrottle_safe(tty);
 		if (!unthrottled)
 			break;
···
  *
  *	n_tty_receive_buf()/producer path:
  *		caller holds non-exclusive termios_rwsem
- *		modifies read_head
- *
- *	read_head is only considered 'published' if canonical mode is
- *	not active.
  */
 
 static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
···
 {
 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
 	ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0;
+	ldata->commit_head = 0;
 	ldata->echo_mark = 0;
 	ldata->line_start = 0;
 
···
 {
 	down_write(&tty->termios_rwsem);
 	reset_buffer_flags(tty->disc_data);
-	n_tty_set_room(tty);
+	n_tty_kick_worker(tty);
 
 	if (tty->link)
 		n_tty_packet_mode_flush(tty);
···
  *
  *	n_tty_receive_buf()/producer path:
  *		caller holds non-exclusive termios_rwsem
- *		modifies read_head
- *
- *	Modifying the read_head is not considered a publish in this context
- *	because canonical mode is active -- only canon_head publishes
  */
 
 static void eraser(unsigned char c, struct tty_struct *tty)
···
  *	Called when a signal is being sent due to terminal input.
  *	Called from the driver receive_buf path so serialized.
  *
+ *	Performs input and output flush if !NOFLSH. In this context, the echo
+ *	buffer is 'output'. The signal is processed first to alert any current
+ *	readers or writers to discontinue and exit their i/o loops.
+ *
  *	Locking: ctrl_lock
  */
 
 static void isig(int sig, struct tty_struct *tty)
 {
+	struct n_tty_data *ldata = tty->disc_data;
 	struct pid *tty_pgrp = tty_get_pgrp(tty);
 	if (tty_pgrp) {
 		kill_pgrp(tty_pgrp, sig, 1);
 		put_pid(tty_pgrp);
+	}
+
+	if (!L_NOFLSH(tty)) {
+		up_read(&tty->termios_rwsem);
+		down_write(&tty->termios_rwsem);
+
+		/* clear echo buffer */
+		mutex_lock(&ldata->output_lock);
+		ldata->echo_head = ldata->echo_tail = 0;
+		ldata->echo_mark = ldata->echo_commit = 0;
+		mutex_unlock(&ldata->output_lock);
+
+		/* clear output buffer */
+		tty_driver_flush_buffer(tty);
+
+		/* clear input buffer */
+		reset_buffer_flags(tty->disc_data);
+
+		/* notify pty master of flush */
+		if (tty->link)
+			n_tty_packet_mode_flush(tty);
+
+		up_write(&tty->termios_rwsem);
+		down_read(&tty->termios_rwsem);
 	}
 }
 
···
  *
  *	n_tty_receive_buf()/producer path:
  *		caller holds non-exclusive termios_rwsem
- *		publishes read_head via put_tty_queue()
  *
  *	Note: may get exclusive termios_rwsem if flushing input buffer
  */
···
 		return;
 	if (I_BRKINT(tty)) {
 		isig(SIGINT, tty);
-		if (!L_NOFLSH(tty)) {
-			/* flushing needs exclusive termios_rwsem */
-			up_read(&tty->termios_rwsem);
-			n_tty_flush_buffer(tty);
-			tty_driver_flush_buffer(tty);
-			down_read(&tty->termios_rwsem);
-		}
 		return;
 	}
 	if (I_PARMRK(tty)) {
···
  *
  *	n_tty_receive_buf()/producer path:
  *		caller holds non-exclusive termios_rwsem
- *		publishes read_head via put_tty_queue()
  */
 static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c)
 {
···
 static void
 n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
 {
-	if (!L_NOFLSH(tty)) {
-		/* flushing needs exclusive termios_rwsem */
-		up_read(&tty->termios_rwsem);
-		n_tty_flush_buffer(tty);
-		tty_driver_flush_buffer(tty);
-		down_read(&tty->termios_rwsem);
-	}
+	isig(signal, tty);
 	if (I_IXON(tty))
 		start_tty(tty);
 	if (L_ECHO(tty)) {
···
 		commit_echoes(tty);
 	} else
 		process_echoes(tty);
-	isig(signal, tty);
 	return;
 }
 
···
  *	n_tty_receive_buf()/producer path:
  *		caller holds non-exclusive termios_rwsem
  *		publishes canon_head if canonical mode is active
- *		otherwise, publishes read_head via put_tty_queue()
  *
  *	Returns 1 if LNEXT was received, else returns 0
  */
···
 handle_newline:
 			set_bit(ldata->read_head & (N_TTY_BUF_SIZE - 1), ldata->read_flags);
 			put_tty_queue(c, ldata);
-			ldata->canon_head = ldata->read_head;
+			smp_store_release(&ldata->canon_head, ldata->read_head);
 			kill_fasync(&tty->fasync, SIGIO, POLL_IN);
 			if (waitqueue_active(&tty->read_wait))
 				wake_up_interruptible_poll(&tty->read_wait, POLLIN);
···
 		n_tty_receive_char_flagged(tty, c, flag);
 }
 
-/**
- *	n_tty_receive_buf	-	data receive
- *	@tty: terminal device
- *	@cp: buffer
- *	@fp: flag buffer
- *	@count: characters
- *
- *	Called by the terminal driver when a block of characters has
- *	been received. This function must be called from soft contexts
- *	not from interrupt context. The driver is responsible for making
- *	calls one at a time and in order (or using flush_to_ldisc)
- *
- *	n_tty_receive_buf()/producer path:
- *		claims non-exclusive termios_rwsem
- *		publishes read_head and canon_head
- */
-
 static void
 n_tty_receive_buf_real_raw(struct tty_struct *tty, const unsigned char *cp,
 			   char *fp, int count)
···
 	size_t n, head;
 
 	head = ldata->read_head & (N_TTY_BUF_SIZE - 1);
-	n = N_TTY_BUF_SIZE - max(read_cnt(ldata), head);
-	n = min_t(size_t, count, n);
+	n = min_t(size_t, count, N_TTY_BUF_SIZE - head);
 	memcpy(read_buf_addr(ldata, head), cp, n);
 	ldata->read_head += n;
 	cp += n;
 	count -= n;
 
 	head = ldata->read_head & (N_TTY_BUF_SIZE - 1);
-	n = N_TTY_BUF_SIZE - max(read_cnt(ldata), head);
-	n = min_t(size_t, count, n);
+	n = min_t(size_t, count, N_TTY_BUF_SIZE - head);
 	memcpy(read_buf_addr(ldata, head), cp, n);
 	ldata->read_head += n;
 }
···
 			tty->ops->flush_chars(tty);
 	}
 
-	if ((!ldata->icanon && (read_cnt(ldata) >= ldata->minimum_to_wake)) ||
-		L_EXTPROC(tty)) {
+	if (ldata->icanon && !L_EXTPROC(tty))
+		return;
+
+	/* publish read_head to consumer */
+	smp_store_release(&ldata->commit_head, ldata->read_head);
+
+	if ((read_cnt(ldata) >= ldata->minimum_to_wake) || L_EXTPROC(tty)) {
 		kill_fasync(&tty->fasync, SIGIO, POLL_IN);
 		if (waitqueue_active(&tty->read_wait))
 			wake_up_interruptible_poll(&tty->read_wait, POLLIN);
 	}
 }
 
+/**
+ *	n_tty_receive_buf_common	-	process input
+ *	@tty: device to receive input
+ *	@cp: input chars
+ *	@fp: flags for each char (if NULL, all chars are TTY_NORMAL)
+ *	@count: number of input chars in @cp
+ *
+ *	Called by the terminal driver when a block of characters has
+ *	been received. This function must be called from soft contexts
+ *	not from interrupt context. The driver is responsible for making
+ *	calls one at a time and in order (or using flush_to_ldisc)
+ *
+ *	Returns the # of input chars from @cp which were processed.
+ *
+ *	In canonical mode, the maximum line length is 4096 chars (including
+ *	the line termination char); lines longer than 4096 chars are
+ *	truncated. After 4095 chars, input data is still processed but
+ *	not stored. Overflow processing ensures the tty can always
+ *	receive more input until at least one line can be read.
+ *
+ *	In non-canonical mode, the read buffer will only accept 4095 chars;
+ *	this provides the necessary space for a newline char if the input
+ *	mode is switched to canonical.
+ *
+ *	Note it is possible for the read buffer to _contain_ 4096 chars
+ *	in non-canonical mode: the read buffer could already contain the
+ *	maximum canon line of 4096 chars when the mode is switched to
+ *	non-canonical.
+ *
+ *	n_tty_receive_buf()/producer path:
+ *		claims non-exclusive termios_rwsem
+ *		publishes commit_head or canon_head
+ */
 static int
 n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
 			 char *fp, int count, int flow)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int room, n, rcvd = 0;
+	int room, n, rcvd = 0, overflow;
 
 	down_read(&tty->termios_rwsem);
 
 	while (1) {
-		room = receive_room(tty);
+		/*
+		 * When PARMRK is set, each input char may take up to 3 chars
+		 * in the read buf; reduce the buffer space avail by 3x
+		 *
+		 * If we are doing input canonicalization, and there are no
+		 * pending newlines, let characters through without limit, so
+		 * that erase characters will be handled.  Other excess
+		 * characters will be beeped.
+		 *
+		 * paired with store in *_copy_from_read_buf() -- guarantees
+		 * the consumer has loaded the data in read_buf up to the new
+		 * read_tail (so this producer will not overwrite unread data)
+		 */
+		size_t tail = smp_load_acquire(&ldata->read_tail);
+
+		room = N_TTY_BUF_SIZE - (ldata->read_head - tail);
+		if (I_PARMRK(tty))
+			room = (room + 2) / 3;
+		room--;
+		if (room <= 0) {
+			overflow = ldata->icanon && ldata->canon_head == tail;
+			if (overflow && room < 0)
+				ldata->read_head--;
+			room = overflow;
+			ldata->no_room = flow && !room;
+		} else
+			overflow = 0;
+
 		n = min(count, room);
-		if (!n) {
-			if (flow && !room)
-				ldata->no_room = 1;
+		if (!n)
 			break;
-		}
-		__receive_buf(tty, cp, fp, n);
+
+		/* ignore parity errors if handling overflow */
+		if (!overflow || !fp || *fp != TTY_PARITY)
+			__receive_buf(tty, cp, fp, n);
+
 		cp += n;
 		if (fp)
 			fp += n;
···
 	}
 
 	tty->receive_room = room;
-	n_tty_check_throttle(tty);
+
+	/* Unthrottle if handling overflow on pty */
+	if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
+		if (overflow) {
+			tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
+			tty_unthrottle_safe(tty);
+			__tty_set_flow_change(tty, 0);
+		}
+	} else
+		n_tty_check_throttle(tty);
+
 	up_read(&tty->termios_rwsem);
 
 	return rcvd;
···
 			ldata->canon_head = ldata->read_head;
 			ldata->push = 1;
 		}
+		ldata->commit_head = ldata->read_head;
 		ldata->erasing = 0;
 		ldata->lnext = 0;
 	}
···
 		else
 			ldata->real_raw = 0;
 	}
-	n_tty_set_room(tty);
 	/*
 	 * Fix tty hang when I_IXON(tty) is cleared, but the tty
 	 * been stopped by STOP_CHAR(tty) before it.
···
 	if (ldata->icanon && !L_EXTPROC(tty))
 		return ldata->canon_head != ldata->read_tail;
 	else
-		return read_cnt(ldata) >= amt;
+		return ldata->commit_head - ldata->read_tail >= amt;
 }
 
 /**
···
 	int retval;
 	size_t n;
 	bool is_eof;
+	size_t head = smp_load_acquire(&ldata->commit_head);
 	size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
 
 	retval = 0;
-	n = min(read_cnt(ldata), N_TTY_BUF_SIZE - tail);
+	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
 	n = min(*nr, n);
 	if (n) {
 		retval = copy_to_user(*b, read_buf_addr(ldata, tail), n);
···
 		is_eof = n == 1 && read_buf(ldata, tail) == EOF_CHAR(tty);
 		tty_audit_add_data(tty, read_buf_addr(ldata, tail), n,
 				ldata->icanon);
-		ldata->read_tail += n;
+		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
 		/* Turn single EOF into zero-length read */
-		if (L_EXTPROC(tty) && ldata->icanon && is_eof && !read_cnt(ldata))
+		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
+		    (head == ldata->read_tail))
 			n = 0;
 		*b += n;
 		*nr -= n;
···
 	bool eof_push = 0;
 
 	/* N.B. avoid overrun if nr == 0 */
-	n = min(*nr, read_cnt(ldata));
+	n = min(*nr, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);
 	if (!n)
 		return 0;
 
···
 
 	if (found)
 		clear_bit(eol, ldata->read_flags);
-	smp_mb__after_atomic();
-	ldata->read_tail += c;
+	smp_store_release(&ldata->read_tail, ldata->read_tail + c);
 
 	if (found) {
 		if (!ldata->push)
···
 	ssize_t retval = 0;
 	long timeout;
 	int packet;
+	size_t tail;
 
 	c = job_control(tty, file);
 	if (c < 0)
···
 	}
 
 	packet = tty->packet;
+	tail = ldata->read_tail;
 
 	add_wait_queue(&tty->read_wait, &wait);
 	while (nr) {
···
 				retval = -ERESTARTSYS;
 				break;
 			}
-			n_tty_set_room(tty);
 			up_read(&tty->termios_rwsem);
 
 			timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
···
 		if (time)
 			timeout = time;
 	}
-	n_tty_set_room(tty);
+	if (tail != ldata->read_tail)
+		n_tty_kick_worker(tty);
 	up_read(&tty->termios_rwsem);
 
 	remove_wait_queue(&tty->read_wait, &wait);

drivers/tty/pty.c

···
 }
 
 /**
- *	pty_space	-	report space left for writing
- *	@to: tty we are writing into
- *
- *	Limit the buffer space used by ptys to 8k.
- */
-
-static int pty_space(struct tty_struct *to)
-{
-	int n = tty_buffer_space_avail(to->port);
-	return min(n, 8192);
-}
-
-/**
  *	pty_write		-	write to a pty
  *	@tty: the tty we write from
  *	@buf: kernel buffer of data
···
 {
 	if (tty->stopped)
 		return 0;
-	return pty_space(tty->link);
+	return tty_buffer_space_avail(tty->link->port);
 }
 
 /**
···
 {
 	struct pid *pgrp;
 
+	if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP)
+		return -EINVAL;
+
 	if (tty->link) {
 		pgrp = tty_get_pgrp(tty->link);
 		if (pgrp)
···
 static void pty_flush_buffer(struct tty_struct *tty)
 {
 	struct tty_struct *to = tty->link;
+	struct tty_ldisc *ld;
 
 	if (!to)
 		return;
-	/* tty_buffer_flush(to); FIXME */
+
+	ld = tty_ldisc_ref(to);
+	tty_buffer_flush(to, ld);
+	if (ld)
+		tty_ldisc_deref(ld);
+
 	if (to->packet) {
 		spin_lock_irq(&tty->ctrl_lock);
 		tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
···
 		goto err_put_module;
 
 	tty_set_lock_subclass(o_tty);
+	lockdep_set_subclass(&o_tty->termios_rwsem, TTY_LOCK_SLAVE);
 
 	if (legacy) {
 		/* We always use new tty termios data so we can do this
···
 	o_tty->link = tty;
 	tty_port_init(ports[0]);
 	tty_port_init(ports[1]);
+	tty_buffer_set_limit(ports[0], 8192);
+	tty_buffer_set_limit(ports[1], 8192);
 	o_tty->port = ports[0];
 	tty->port = ports[1];
 	o_tty->port->itty = o_tty;
+
+	tty_buffer_set_lock_subclass(o_tty->port);
 
 	tty_driver_kref_get(driver);
 	tty->count++;

drivers/tty/rocket.c

···
 	       tty->ldisc.chars_in_buffer(tty));
 #endif
 
-	if (rocket_paranoia_check(info, "rp_throttle"))
+	if (rocket_paranoia_check(info, "rp_unthrottle"))
 		return;
 
 	if (I_IXOFF(tty))
···
 
 	orig_jiffies = jiffies;
 #ifdef ROCKET_DEBUG_WAIT_UNTIL_SENT
-	printk(KERN_INFO "In RP_wait_until_sent(%d) (jiff=%lu)...\n", timeout,
+	printk(KERN_INFO "In %s(%d) (jiff=%lu)...\n", __func__, timeout,
 	       jiffies);
 	printk(KERN_INFO "cps=%d...\n", info->cps);
 #endif

drivers/tty/serial/8250/8250_core.c

···
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
 		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
 	},
+/* tx_loadsz is set to 63-bytes instead of 64-bytes to implement
+workaround of errata A-008006 which states that tx_loadsz should  be
+configured less than Maximum supported fifo bytes */
+	[PORT_16550A_FSL64] = {
+		.name		= "16550A_FSL64",
+		.fifo_size	= 64,
+		.tx_loadsz	= 63,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
+				  UART_FCR7_64BYTE,
+		.flags		= UART_CAP_FIFO,
+	},
 };
 
 /* Uart divisor latch read */
···
 			up->port.type = PORT_16650;
 			up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
 		} else {
-			DEBUG_AUTOCONF("Motorola 8xxx DUART ");
+			serial_out(up, UART_LCR, 0);
+			serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+				   UART_FCR7_64BYTE);
+			status1 = serial_in(up, UART_IIR) >> 5;
+			serial_out(up, UART_FCR, 0);
+			serial_out(up, UART_LCR, 0);
+
+			if (status1 == 7)
+				up->port.type = PORT_16550A_FSL64;
+			else
+				DEBUG_AUTOCONF("Motorola 8xxx DUART ");
 		}
 		serial_out(up, UART_EFR, 0);
 		return;
···
 	struct uart_8250_port *up = up_to_u8250p(port);
 
 	serial8250_rpm_get_tx(up);
-	if (up->dma && !up->dma->tx_dma(up)) {
+
+	if (up->dma && !up->dma->tx_dma(up))
 		return;
-	} else if (!(up->ier & UART_IER_THRI)) {
+
+	if (!(up->ier & UART_IER_THRI)) {
 		up->ier |= UART_IER_THRI;
 		serial_port_out(port, UART_IER, up->ier);
 
···
 			unsigned char lsr;
 			lsr = serial_in(up, UART_LSR);
 			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
-			if (lsr & UART_LSR_TEMT)
+			if (lsr & UART_LSR_THRE)
 				serial8250_tx_chars(up);
 		}
 	}
···
 	return ret;
 }
 
-static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned char mcr = 0;
···
 	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
 
 	serial_port_out(port, UART_MCR, mcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_do_set_mctrl);
+
+static void serial8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	if (port->set_mctrl)
+		return port->set_mctrl(port, mctrl);
+	return serial8250_do_set_mctrl(port, mctrl);
 }
 
 static void serial8250_break_ctl(struct uart_port *port, int break_state)
···
 		serial8250_do_shutdown(port);
 }
 
-static unsigned int serial8250_get_divisor(struct uart_port *port, unsigned int baud)
+/*
+ * XR17V35x UARTs have an extra fractional divisor register (DLD)
+ * Calculate divisor with extra 4-bit fractional portion
+ */
+static unsigned int xr17v35x_get_divisor(struct uart_8250_port *up,
+					 unsigned int baud,
+					 unsigned int *frac)
 {
+	struct uart_port *port = &up->port;
+	unsigned int quot_16;
+
+	quot_16 = DIV_ROUND_CLOSEST(port->uartclk, baud);
+	*frac = quot_16 & 0x0f;
+
+	return quot_16 >> 4;
+}
+
+static unsigned int serial8250_get_divisor(struct uart_8250_port *up,
+					   unsigned int baud,
+					   unsigned int *frac)
+{
+	struct uart_port *port = &up->port;
 	unsigned int quot;
 
 	/*
 	 * Handle magic divisors for baud rates above baud_base on
 	 * SMSC SuperIO chips.
+	 *
 	 */
 	if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
 	    baud == (port->uartclk/4))
···
 	else if ((port->flags & UPF_MAGIC_MULTIPLIER) &&
 		 baud == (port->uartclk/8))
 		quot = 0x8002;
+	else if (up->port.type == PORT_XR17V35X)
+		quot = xr17v35x_get_divisor(up, baud, frac);
 	else
 		quot = uart_get_divisor(port, baud);
+
+	/*
+	 * Oxford Semi 952 rev B workaround
+	 */
+	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
+		quot++;
 
 	return quot;
 }
 
-void
-serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
-		          struct ktermios *old)
+static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
+					    tcflag_t c_cflag)
 {
-	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned char cval;
-	unsigned long flags;
-	unsigned int baud, quot;
 
-	switch (termios->c_cflag & CSIZE) {
+	switch (c_cflag & CSIZE) {
 	case CS5:
 		cval = UART_LCR_WLEN5;
 		break;
···
 		break;
 	}
 
-	if (termios->c_cflag & CSTOPB)
+	if (c_cflag & CSTOPB)
 		cval |= UART_LCR_STOP;
-	if (termios->c_cflag & PARENB) {
+	if (c_cflag & PARENB) {
 		cval |= UART_LCR_PARITY;
 		if (up->bugs & UART_BUG_PARITY)
 			up->fifo_bug = true;
 	}
-	if (!(termios->c_cflag & PARODD))
+	if (!(c_cflag & PARODD))
 		cval |= UART_LCR_EPAR;
 #ifdef CMSPAR
-	if (termios->c_cflag & CMSPAR)
+	if (c_cflag & CMSPAR)
 		cval |= UART_LCR_SPAR;
 #endif
+
+	return cval;
+}
+
+static void serial8250_set_divisor(struct uart_port *port, unsigned int baud,
+			    unsigned int quot, unsigned int quot_frac)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
+	if (is_omap1510_8250(up)) {
+		if (baud == 115200) {
+			quot = 1;
+			serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1);
+		} else
+			serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0);
+	}
+
+	/*
+	 * For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2,
+	 * otherwise just set DLAB
+	 */
+	if (up->capabilities & UART_NATSEMI)
+		serial_port_out(port, UART_LCR, 0xe0);
+	else
+		serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
+
+	serial_dl_write(up, quot);
+
+	/* XR17V35x UARTs have an extra fractional divisor register (DLD) */
+	if (up->port.type == PORT_XR17V35X)
+		serial_port_out(port, 0x2, quot_frac);
+}
+
+void
+serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
+		          struct ktermios *old)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned char cval;
+	unsigned long flags;
+	unsigned int baud, quot, frac = 0;
+
+	cval = serial8250_compute_lcr(up, termios->c_cflag);
 
 	/*
 	 * Ask the core to calculate the divisor for us.
···
 	baud = uart_get_baud_rate(port, termios, old,
 				  port->uartclk / 16 / 0xffff,
 				  port->uartclk / 16);
-	quot = serial8250_get_divisor(port, baud);
+	quot = serial8250_get_divisor(up, baud, &frac);
 
 	/*
-	 * Oxford Semi 952 rev B workaround
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
 	 */
-	if (up->bugs & UART_BUG_QUOT && (quot & 0xff) == 0)
-		quot++;
+	serial8250_rpm_get(up);
+	spin_lock_irqsave(&port->lock, flags);
+
+	up->lcr = cval;					/* Save computed LCR */
 
 	if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) {
 		/* NOTE: If fifo_bug is not set, a user can set RX_trigger. */
···
 		if (termios->c_cflag & CRTSCTS)
 			up->mcr |= UART_MCR_AFE;
 	}
-
-	/*
-	 * Ok, we're now changing the port state.  Do it with
-	 * interrupts disabled.
-	 */
-	serial8250_rpm_get(up);
-	spin_lock_irqsave(&port->lock, flags);
 
 	/*
 	 * Update the per-port timeout.
···
 			serial_port_out(port, UART_EFR, efr);
 	}
 
-	/* Workaround to enable 115200 baud on OMAP1510 internal ports */
-	if (is_omap1510_8250(up)) {
-		if (baud == 115200) {
-			quot = 1;
-			serial_port_out(port, UART_OMAP_OSC_12M_SEL, 1);
-		} else
-			serial_port_out(port, UART_OMAP_OSC_12M_SEL, 0);
-	}
-
-	/*
-	 * For NatSemi, switch to bank 2 not bank 1, to avoid resetting EXCR2,
-	 * otherwise just set DLAB
-	 */
-	if (up->capabilities & UART_NATSEMI)
-		serial_port_out(port, UART_LCR, 0xe0);
-	else
-		serial_port_out(port, UART_LCR, cval | UART_LCR_DLAB);
-
-	serial_dl_write(up, quot);
-
-	/*
-	 * XR17V35x UARTs have an extra fractional divisor register (DLD)
-	 *
-	 * We need to recalculate all of the registers, because DLM and DLL
-	 * are already rounded to a whole integer.
-	 *
-	 * When recalculating we use a 32x clock instead of a 16x clock to
-	 * allow 1-bit for rounding in the fractional part.
-	 */
-	if (up->port.type == PORT_XR17V35X) {
-		unsigned int baud_x32 = (port->uartclk * 2) / baud;
-		u16 quot = baud_x32 / 32;
-		u8 quot_frac = DIV_ROUND_CLOSEST(baud_x32 % 32, 2);
-
-		serial_dl_write(up, quot);
-		serial_port_out(port, 0x2, quot_frac & 0xf);
-	}
+	serial8250_set_divisor(port, baud, quot, frac);
 
 	/*
 	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
···
 	if (port->type == PORT_16750)
 		serial_port_out(port, UART_FCR, up->fcr);
 
-	serial_port_out(port, UART_LCR, cval);		/* reset DLAB */
-	up->lcr = cval;					/* Save LCR */
+	serial_port_out(port, UART_LCR, up->lcr);	/* reset DLAB */
 	if (port->type != PORT_16750) {
 		/* emulated UARTs (Lucent Venus 167x) need two steps */
 		if (up->fcr & UART_FCR_ENABLE_FIFO)
···
 	else
 		serial_port_out(port, UART_IER, 0);
 
+	/* check scratch reg to see if port powered off during system sleep */
+	if (up->canary && (up->canary != serial_port_in(port, UART_SCR))) {
+		struct ktermios termios;
+		unsigned int baud, quot, frac = 0;
+
+		termios.c_cflag = port->cons->cflag;
+		if (port->state->port.tty && termios.c_cflag == 0)
+			termios.c_cflag = port->state->port.tty->termios.c_cflag;
+
+		baud = uart_get_baud_rate(port, &termios, NULL,
+					  port->uartclk / 16 / 0xffff,
+					  port->uartclk / 16);
+		quot = serial8250_get_divisor(up, baud, &frac);
+
+		serial8250_set_divisor(port, baud, quot, frac);
+		serial_port_out(port, UART_LCR, up->lcr);
+		serial_port_out(port, UART_MCR, UART_MCR_DTR | UART_MCR_RTS);
+
+		up->canary = 0;
+	}
+
 	uart_console_write(port, s, count, serial8250_console_putchar);
 
 	/*
···
  */
 void serial8250_suspend_port(int line)
 {
-	uart_suspend_port(&serial8250_reg, &serial8250_ports[line].port);
+	struct uart_8250_port *up = &serial8250_ports[line];
+	struct uart_port *port = &up->port;
+
+	if (!console_suspend_enabled && uart_console(port) &&
+	    port->type != PORT_8250) {
+		unsigned char canary = 0xa5;
+		serial_out(up, UART_SCR, canary);
+		up->canary = canary;
+	}
+
+	uart_suspend_port(&serial8250_reg, port);
 }
 
 /**
···
 {
 	struct uart_8250_port *up = &serial8250_ports[line];
 	struct uart_port *port = &up->port;
+
+	up->canary = 0;
 
 	if (up->capabilities & UART_NATSEMI) {
 		/* Ensure it's still in high speed mode */
···
 		/*  Possibly override set_termios call */
 		if (up->port.set_termios)
 			uart->port.set_termios = up->port.set_termios;
+		if (up->port.set_mctrl)
+			uart->port.set_mctrl = up->port.set_mctrl;
 		if (up->port.startup)
 			uart->port.startup = up->port.startup;
 		if (up->port.shutdown)

drivers/tty/serial/8250/8250_dma.c

···
 
 	dma->rx_running = 0;
 	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
-	dmaengine_terminate_all(dma->rxchan);
 
 	count = dma->rx_size - state.residue;
 
···
 		return 0;
 
 	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (dma->tx_size < p->port.fifosize) {
+		ret = -EINVAL;
+		goto err;
+	}
 
 	desc = dmaengine_prep_slave_single(dma->txchan,
 					   dma->tx_addr + xmit->tail,
···
 		if (dma->rx_running) {
 			dmaengine_pause(dma->rxchan);
 			__dma_rx_complete(p);
+			dmaengine_terminate_all(dma->rxchan);
 		}
 		return -ETIMEDOUT;
 	default:

drivers/tty/serial/8250/8250_dw.c

···
 static int dw8250_probe_acpi(struct uart_8250_port *up,
 			     struct dw8250_data *data)
 {
+	const struct acpi_device_id *id;
 	struct uart_port *p = &up->port;
 
 	dw8250_setup_port(up);
+
+	id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev);
+	if (!id)
+		return -ENODEV;
+
+	if (!p->uartclk)
+		if (device_property_read_u32(p->dev, "clock-frequency",
+					     &p->uartclk))
+			return -EINVAL;
 
 	p->iotype = UPIO_MEM32;
 	p->serial_in = dw8250_serial_in32;
···
 	{ "INT3435", 0 },
 	{ "80860F0A", 0 },
 	{ "8086228A", 0 },
+	{ "APMC0D08", 0},
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);

drivers/tty/serial/8250/8250_early.c

···
 	struct uart_port *port = &early_device->port;
 	unsigned int ier;
 
-	/* Save the IER and disable interrupts */
+	/* Save the IER and disable interrupts preserving the UUE bit */
 	ier = serial8250_early_in(port, UART_IER);
-	serial8250_early_out(port, UART_IER, 0);
+	if (ier)
+		serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
 
 	uart_console_write(port, s, count, serial_putc);
 
 	/* Wait for transmitter to become empty and restore the IER */
 	wait_for_xmitr(port);
-	serial8250_early_out(port, UART_IER, ier);
+
+	if (ier)
+		serial8250_early_out(port, UART_IER, ier);
 }
 
 static unsigned int __init probe_baud(struct uart_port *port)
···
 	struct uart_port *port = &device->port;
 	unsigned int divisor;
 	unsigned char c;
+	unsigned int ier;
 
 	serial8250_early_out(port, UART_LCR, 0x3);	/* 8n1 */
-	serial8250_early_out(port, UART_IER, 0);	/* no interrupt */
+	ier = serial8250_early_in(port, UART_IER);
+	serial8250_early_out(port, UART_IER, ier & UART_IER_UUE); /* no interrupt */
 	serial8250_early_out(port, UART_FCR, 0);	/* no fifo */
 	serial8250_early_out(port, UART_MCR, 0x3);	/* DTR + RTS */
 

drivers/tty/serial/8250/8250_omap.c

···
 	return readl(up->port.membase + (reg << up->port.regshift));
 }
 
+static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct omap8250_priv *priv = up->port.private_data;
+	u8 lcr;
+
+	serial8250_do_set_mctrl(port, mctrl);
+
+	/*
+	 * Turn off autoRTS if RTS is lowered and restore autoRTS setting
+	 * if RTS is raised
+	 */
+	lcr = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+		priv->efr |= UART_EFR_RTS;
+	else
+		priv->efr &= ~UART_EFR_RTS;
+	serial_out(up, UART_EFR, priv->efr);
+	serial_out(up, UART_LCR, lcr);
+}
+
 /*
  * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
  * The access to uart register after MDR1 Access
···
 
 	priv->efr = 0;
 	up->mcr &= ~(UART_MCR_RTS | UART_MCR_XONANY);
-	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
-		/* Enable AUTORTS and AUTOCTS */
-		priv->efr |= UART_EFR_CTS | UART_EFR_RTS;
+	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
 
-		/* Ensure MCR RTS is asserted */
-		up->mcr |= UART_MCR_RTS;
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
+		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+		priv->efr |= UART_EFR_CTS;
 	} else	if (up->port.flags & UPF_SOFT_FLOW) {
 		/*
 		 * IXON Flag:
···
 		 * Enable XON/XOFF flow control on output.
 		 * Transmit XON1, XOFF1
 		 */
-		if (termios->c_iflag & IXOFF)
+		if (termios->c_iflag & IXOFF) {
+			up->port.status |= UPSTAT_AUTOXOFF;
 			priv->efr |= OMAP_UART_SW_TX;
+		}
 
 		/*
 		 * IXANY Flag:
···
 static void omap_8250_pm(struct uart_port *port, unsigned int state,
 			 unsigned int oldstate)
 {
-	struct uart_8250_port *up =
-		container_of(port, struct uart_8250_port, port);
-	struct omap8250_priv *priv = up->port.private_data;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	u8 efr;
 
 	pm_runtime_get_sync(port->dev);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, priv->efr | UART_EFR_ECB);
+	efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
 	serial_out(up, UART_LCR, 0);
 
 	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, priv->efr);
+	serial_out(up, UART_EFR, efr);
 	serial_out(up, UART_LCR, 0);
 
 	pm_runtime_mark_last_busy(port->dev);
···
 	up.capabilities |= UART_CAP_RPM;
 #endif
 	up.port.set_termios = omap_8250_set_termios;
+	up.port.set_mctrl = omap8250_set_mctrl;
 	up.port.pm = omap_8250_pm;
 	up.port.startup = omap_8250_startup;
 	up.port.shutdown = omap_8250_shutdown;
···
 }
 #endif
 
+#ifdef CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP
+static int __init omap8250_console_fixup(void)
+{
+	char *omap_str;
+	char *options;
+	u8 idx;
+
+	if (strstr(boot_command_line, "console=ttyS"))
+		/* user set a ttyS based name for the console */
+		return 0;
+
+	omap_str = strstr(boot_command_line, "console=ttyO");
+	if (!omap_str)
+		/* user did not set ttyO based console, so we don't care */
+		return 0;
+
+	omap_str += 12;
+	if ('0' <= *omap_str && *omap_str <= '9')
+		idx = *omap_str - '0';
+	else
+		return 0;
+
+	omap_str++;
+	if (omap_str[0] == ',') {
+		omap_str++;
+		options = omap_str;
+	} else {
+		options = NULL;
+	}
+
+	add_preferred_console("ttyS", idx, options);
+	pr_err("WARNING: Your 'console=ttyO%d' has been replaced by 'ttyS%d'\n",
+	       idx, idx);
+	pr_err("This ensures that you still see kernel messages. Please\n");
+	pr_err("update your kernel commandline.\n");
+	return 0;
+}
+console_initcall(omap8250_console_fixup);
+#endif
+
 static const struct dev_pm_ops omap8250_dev_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume)
 	SET_RUNTIME_PM_OPS(omap8250_runtime_suspend,
···
 		.name		= "omap8250",
 		.pm		= &omap8250_dev_pm_ops,
 		.of_match_table = omap8250_dt_ids,
-		.owner		= THIS_MODULE,
 	},
 	.probe			= omap8250_probe,
 	.remove			= omap8250_remove,

drivers/tty/serial/8250/8250_pci.c

···
  */
 static int pci_inteli960ni_init(struct pci_dev *dev)
 {
-	unsigned long oldval;
+	u32 oldval;
 
 	if (!(dev->subsystem_device & 0x1000))
 		return -ENODEV;
 
 	/* is firmware started? */
-	pci_read_config_dword(dev, 0x44, (void *)&oldval);
+	pci_read_config_dword(dev, 0x44, &oldval);
 	if (oldval == 0x00001000L) { /* RESET value */
 		dev_dbg(&dev->dev, "Local i960 firmware missing\n");
 		return -ENODEV;

drivers/tty/serial/8250/8250_pnp.c

···
 static int
 serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
-	struct uart_8250_port uart;
+	struct uart_8250_port uart, *port;
 	int ret, line, flags = dev_id->driver_data;
 
 	if (flags & UNKNOWN_DEV) {
···
 	if (line < 0 || (flags & CIR_PORT))
 		return -ENODEV;
 
+	port = serial8250_get_port(line);
+	if (uart_console(&port->port))
+		dev->capabilities |= PNP_CONSOLE;
+
 	pnp_set_drvdata(dev, (void *)((long)line + 1));
 	return 0;
 }
···
 static void serial_pnp_remove(struct pnp_dev *dev)
 {
 	long line = (long)pnp_get_drvdata(dev);
+
+	dev->capabilities &= ~PNP_CONSOLE;
 	if (line)
 		serial8250_unregister_port(line - 1);
 }

drivers/tty/serial/8250/Kconfig

···
 
 	  This driver uses ttyS instead of ttyO.
 
+config SERIAL_8250_OMAP_TTYO_FIXUP
+	bool "Replace ttyO with ttyS"
+	depends on SERIAL_8250_OMAP=y && SERIAL_8250_CONSOLE
+	default y
+	help
+	  This option replaces the "console=ttyO" argument with the matching
+	  ttyS argument if the user did not specified it on the command line.
+	  This ensures that the user can see the kernel output during boot
+	  which he wouldn't see otherwise. The getty has still to be configured
+	  for ttyS instead of ttyO regardless of this option.
+	  This option is intended for people who "automatically" enable this
+	  driver without knowing that this driver requires a different console=
+	  argument. If you read this, please keep this option disabled and
+	  instead update your kernel command line. If you prepare a kernel for a
+	  distribution or other kind of larger user base then you probably want
+	  to keep this option enabled. Otherwise people might complain about a
+	  not booting kernel because the serial console remains silent in case
+	  they forgot to update the command line.
+
 config SERIAL_8250_FINTEK
 	tristate "Support for Fintek F81216A LPC to 4 UART"
 	depends on SERIAL_8250 && PNP

drivers/tty/serial/Kconfig

···
 	tristate "Samsung SoC serial support"
 	depends on PLAT_SAMSUNG || ARCH_EXYNOS
 	select SERIAL_CORE
+	select SERIAL_EARLYCON
 	help
 	  Support for the on-chip UARTs on the Samsung S3C24XX series CPUs,
 	  providing /dev/ttySAC0, 1 and 2 (note, some machines may not
···
 	  "console=ttySA0". (Try "man bootparam" or see the documentation of
 	  your boot loader (lilo or loadlin) about how to pass options to the
 	  kernel at boot time.)
-
-config SERIAL_MRST_MAX3110
-	tristate "SPI UART driver for Max3110"
-	depends on SPI_DW_PCI
-	select SERIAL_CORE
-	select SERIAL_CORE_CONSOLE
-	help
-	  This is the UART protocol driver for the MAX3110 device on
-	  the Intel Moorestown platform. On other systems use the max3100
-	  driver.
 
 config SERIAL_MFD_HSU
 	tristate "Medfield High Speed UART support"
···
 	depends on SERIAL_VT8500=y
 	select SERIAL_CORE_CONSOLE
 
+config SERIAL_ETRAXFS
+	bool "ETRAX FS serial port support"
+	depends on ETRAX_ARCH_V32 && OF
+	select SERIAL_CORE
+
+config SERIAL_ETRAXFS_CONSOLE
+	bool "ETRAX FS serial console support"
+	depends on SERIAL_ETRAXFS
+	select SERIAL_CORE_CONSOLE
+
 config SERIAL_NETX
 	tristate "NetX serial port support"
 	depends on ARCH_NETX
···
 	  If you have enabled the lpuart serial port on the Freescale SoCs,
 	  you can make it the console by answering Y to this option.
 
+config SERIAL_CONEXANT_DIGICOLOR
+	tristate "Conexant Digicolor CX92xxx USART serial port support"
+	depends on OF
+	select SERIAL_CORE
+	help
+	  Support for the on-chip USART on Conexant Digicolor SoCs.
+
+config SERIAL_CONEXANT_DIGICOLOR_CONSOLE
+	bool "Console on Conexant Digicolor serial port"
+	depends on SERIAL_CONEXANT_DIGICOLOR=y
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the USART serial port on Conexant Digicolor
+	  SoCs, you can make it the console by answering Y to this option.
+
 config SERIAL_ST_ASC
 	tristate "ST ASC serial port support"
 	select SERIAL_CORE
···
 
 	  This driver can also be build as a module. If so, the module will be called
 	  men_z135_uart.ko
+
+config SERIAL_SPRD
+	tristate "Support for Spreadtrum serial"
+	depends on ARCH_SPRD
+	select SERIAL_CORE
+	help
+	  This enables the driver for the Spreadtrum's serial.
+
+config SERIAL_SPRD_CONSOLE
+	bool "Spreadtrum UART console support"
+	depends on SERIAL_SPRD=y
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Support for early debug console using Spreadtrum's serial. This enables
+	  the console before standard serial driver is probed. This is enabled
+	  with "earlycon" on the kernel command line. The console is
+	  enabled when early_param is processed.
 
 endmenu
 

drivers/tty/serial/Makefile

···
 obj-$(CONFIG_SERIAL_MESON) += meson_uart.o
 obj-$(CONFIG_SERIAL_SB1250_DUART) += sb1250-duart.o
 obj-$(CONFIG_ETRAX_SERIAL) += crisv10.o
+obj-$(CONFIG_SERIAL_ETRAXFS) += etraxfs-uart.o
 obj-$(CONFIG_SERIAL_SCCNXP) += sccnxp.o
 obj-$(CONFIG_SERIAL_SC16IS7XX) += sc16is7xx.o
 obj-$(CONFIG_SERIAL_JSM) += jsm/
···
 obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o
 obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
 obj-$(CONFIG_SERIAL_VT8500) += vt8500_serial.o
-obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
 obj-$(CONFIG_SERIAL_IFX6X60)  	+= ifx6x60.o
 obj-$(CONFIG_SERIAL_PCH_UART)	+= pch_uart.o
···
 obj-$(CONFIG_SERIAL_ARC)	+= arc_uart.o
 obj-$(CONFIG_SERIAL_RP2)	+= rp2.o
 obj-$(CONFIG_SERIAL_FSL_LPUART)	+= fsl_lpuart.o
+obj-$(CONFIG_SERIAL_CONEXANT_DIGICOLOR)	+= digicolor-usart.o
 obj-$(CONFIG_SERIAL_MEN_Z135)	+= men_z135_uart.o
+obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
 
 # GPIOLIB helpers for modem control lines
 obj-$(CONFIG_SERIAL_MCTRL_GPIO)	+= serial_mctrl_gpio.o

drivers/tty/serial/altera_jtaguart.c

···
 	port->iotype = SERIAL_IO_MEM;
 	port->ops = &altera_jtaguart_ops;
 	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
 
 	uart_add_one_port(&altera_jtaguart_driver, port);
 

drivers/tty/serial/altera_uart.c

···
 	port->iotype = SERIAL_IO_MEM;
 	port->ops = &altera_uart_ops;
 	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
 
 	platform_set_drvdata(pdev, port);
 

drivers/tty/serial/atmel_serial.c

···
 static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)
 {
 	unsigned int control = 0;
-	unsigned int mode;
+	unsigned int mode = UART_GET_MR(port);
+	unsigned int rts_paused, rts_ready;
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 
+	/* override mode to RS485 if needed, otherwise keep the current mode */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if ((port->rs485.delay_rts_after_send) > 0)
+			UART_PUT_TTGR(port, port->rs485.delay_rts_after_send);
+		mode &= ~ATMEL_US_USMODE;
+		mode |= ATMEL_US_USMODE_RS485;
+	}
+
+	/* set the RTS line state according to the mode */
+	if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
+		/* force RTS line to high level */
+		rts_paused = ATMEL_US_RTSEN;
+
+		/* give the control of the RTS line back to the hardware */
+		rts_ready = ATMEL_US_RTSDIS;
+	} else {
+		/* force RTS line to high level */
+		rts_paused = ATMEL_US_RTSDIS;
+
+		/* force RTS line to low level */
+		rts_ready = ATMEL_US_RTSEN;
+	}
+
 	if (mctrl & TIOCM_RTS)
-		control |= ATMEL_US_RTSEN;
+		control |= rts_ready;
 	else
-		control |= ATMEL_US_RTSDIS;
+		control |= rts_paused;
 
 	if (mctrl & TIOCM_DTR)
 		control |= ATMEL_US_DTREN;
···
 	mctrl_gpio_set(atmel_port->gpios, mctrl);
 
 	/* Local loopback mode? */
-	mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;
+	mode &= ~ATMEL_US_CHMODE;
 	if (mctrl & TIOCM_LOOP)
 		mode |= ATMEL_US_CHMODE_LOC_LOOP;
 	else
 		mode |= ATMEL_US_CHMODE_NORMAL;
 
-	/* Resetting serial mode to RS232 (0x0) */
-	mode &= ~ATMEL_US_USMODE;
-
-	if (port->rs485.flags & SER_RS485_ENABLED) {
-		dev_dbg(port->dev, "Setting UART to RS485\n");
-		if ((port->rs485.delay_rts_after_send) > 0)
-			UART_PUT_TTGR(port, port->rs485.delay_rts_after_send);
-		mode |= ATMEL_US_USMODE_RS485;
-	} else {
-		dev_dbg(port->dev, "Setting UART to RS232\n");
-	}
 	UART_PUT_MR(port, mode);
 }
 
···
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(port);
 
-	/* Do we really need this? */
+	/*
+	 * xmit is a circular buffer so, if we have just send data from
+	 * xmit->tail to the end of xmit->buf, now we have to transmit the
+	 * remaining data from the beginning of xmit->buf to xmit->head.
+	 */
 	if (!uart_circ_empty(xmit))
 		tasklet_schedule(&atmel_port->tasklet);
 
···
 		BUG_ON(!sg_dma_len(sg));
 
 		desc = dmaengine_prep_slave_sg(chan,
-						sg,
-						1,
-						DMA_MEM_TO_DEV,
-						DMA_PREP_INTERRUPT |
-						DMA_CTRL_ACK);
+					       sg,
+					       1,
+					       DMA_MEM_TO_DEV,
+					       DMA_PREP_INTERRUPT |
+					       DMA_CTRL_ACK);
 		if (!desc) {
 			dev_err(port->dev, "Failed to send via dma!\n");
 			return;
 		}
 
-		dma_sync_sg_for_device(port->dev, sg, 1, DMA_MEM_TO_DEV);
+		dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
 
 		atmel_port->desc_tx = desc;
 		desc->callback = atmel_complete_tx_dma;
···
 	dma_sync_sg_for_cpu(port->dev,
 			    &atmel_port->sg_rx,
 			    1,
-			    DMA_DEV_TO_MEM);
+			    DMA_FROM_DEVICE);
 
 	/*
 	 * ring->head points to the end of data already written by the DMA.
···
 	dma_sync_sg_for_device(port->dev,
 			       &atmel_port->sg_rx,
 			       1,
-			       DMA_DEV_TO_MEM);
+			       DMA_FROM_DEVICE);
 
 	/*
 	 * Drop the lock here since it might end up calling
···
 	/* UART circular rx buffer is an aligned page. */
 	BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);
 	sg_set_page(&atmel_port->sg_rx,
-			virt_to_page(ring->buf),
-			ATMEL_SERIAL_RINGSIZE,
-			(int)ring->buf & ~PAGE_MASK);
-			nent = dma_map_sg(port->dev,
-					&atmel_port->sg_rx,
-					1,
-					DMA_FROM_DEVICE);
+		    virt_to_page(ring->buf),
+		    ATMEL_SERIAL_RINGSIZE,
+		    (int)ring->buf & ~PAGE_MASK);
+	nent = dma_map_sg(port->dev,
+			  &atmel_port->sg_rx,
+			  1,
+			  DMA_FROM_DEVICE);
 
 	if (!nent) {
 		dev_dbg(port->dev, "need to release resource of dma\n");
···
 	 * each one is half ring buffer size
 	 */
 	desc = dmaengine_prep_dma_cyclic(atmel_port->chan_rx,
-				sg_dma_address(&atmel_port->sg_rx),
-				sg_dma_len(&atmel_port->sg_rx),
-				sg_dma_len(&atmel_port->sg_rx)/2,
-				DMA_DEV_TO_MEM,
-				DMA_PREP_INTERRUPT);
+					 sg_dma_address(&atmel_port->sg_rx),
+					 sg_dma_len(&atmel_port->sg_rx),
+					 sg_dma_len(&atmel_port->sg_rx)/2,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
 	desc->callback = atmel_complete_rx_dma;
 	desc->callback_param = port;
 	atmel_port->desc_rx = desc;
···
 			      struct ktermios *old)
 {
 	unsigned long flags;
-	unsigned int mode, imr, quot, baud;
+	unsigned int old_mode, mode, imr, quot, baud;
 
-	/* Get current mode register */
-	mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
-					| ATMEL_US_NBSTOP | ATMEL_US_PAR
-					| ATMEL_US_USMODE);
+	/* save the current mode register */
+	mode = old_mode = UART_GET_MR(port);
+
+	/* reset the mode, clock divisor, parity, stop bits and data size */
+	mode &= ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP |
+		  ATMEL_US_PAR | ATMEL_US_USMODE);
 
 	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
 	quot = uart_get_divisor(port, baud);
···
 	} else
 		mode |= ATMEL_US_PAR_NONE;
 
-	/* hardware handshake (RTS/CTS) */
-	if (termios->c_cflag & CRTSCTS)
-		mode |= ATMEL_US_USMODE_HWHS;
-	else
-		mode |= ATMEL_US_USMODE_NORMAL;
-
 	spin_lock_irqsave(&port->lock, flags);
 
 	port->read_status_mask = ATMEL_US_OVRE;
···
 	/* disable receiver and transmitter */
 	UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
 
-	/* Resetting serial mode to RS232 (0x0) */
-	mode &= ~ATMEL_US_USMODE;
-
+	/* mode */
 	if (port->rs485.flags & SER_RS485_ENABLED) {
 		if ((port->rs485.delay_rts_after_send) > 0)
 			UART_PUT_TTGR(port, port->rs485.delay_rts_after_send);
 		mode |= ATMEL_US_USMODE_RS485;
+	} else if (termios->c_cflag & CRTSCTS) {
+		/* RS232 with hardware handshake (RTS/CTS) */
+		mode |= ATMEL_US_USMODE_HWHS;
+	} else {
+		/* RS232 without hadware handshake */
+		mode |= ATMEL_US_USMODE_NORMAL;
 	}
 
-	/* set the parity, stop bits and data size */
+	/* set the mode, clock divisor, parity, stop bits and data size */
 	UART_PUT_MR(port, mode);
+
+	/*
+	 * when switching the mode, set the RTS line state according to the
+	 * new mode, otherwise keep the former state
+	 */
+	if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
+		unsigned int rts_state;
+
+		if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
+			/* let the hardware control the RTS line */
+			rts_state = ATMEL_US_RTSDIS;
+		} else {
+			/* force RTS line to low level */
+			rts_state = ATMEL_US_RTSEN;
+		}
+
+		UART_PUT_CR(port, rts_state);
+	}
 
 	/* set the baud rate */
 	UART_PUT_BRGR(port, quot);
···
 
 	ret = atmel_init_port(port, pdev);
 	if (ret)
-		goto err;
+		goto err_clear_bit;
 
 	if (!atmel_use_pdc_rx(&port->uart)) {
 		ret = -ENOMEM;
···
 	device_init_wakeup(&pdev->dev, 1);
 	platform_set_drvdata(pdev, port);
 
+	/*
+	 * The peripheral clock has been disabled by atmel_init_port():
+	 * enable it before accessing I/O registers
+	 */
+	clk_prepare_enable(port->clk);
+
 	if (rs485_enabled) {
 		UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
 		UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
···
 	 * Get port name of usart or uart
 	 */
 	atmel_get_ip_name(&port->uart);
+
+	/*
+	 * The peripheral clock can now safely be disabled till the port
+	 * is used
+	 */
+	clk_disable_unprepare(port->clk);
 
 	return 0;
 
···
 		clk_put(port->clk);
 		port->clk = NULL;
 	}
+err_clear_bit:
+	clear_bit(port->uart.line, atmel_ports_in_use);
 err:
 	return ret;
 }

drivers/tty/serial/digicolor-usart.c

···
+/*
+ *  Driver for Conexant Digicolor serial ports (USART)
+ *
+ * Author: Baruch Siach <[e-mail]>
+ *
+ * Copyright (C) 2014 Paradox Innovation Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+
+#define UA_ENABLE			0x00
+#define UA_ENABLE_ENABLE		BIT(0)
+
+#define UA_CONTROL			0x01
+#define UA_CONTROL_RX_ENABLE		BIT(0)
+#define UA_CONTROL_TX_ENABLE		BIT(1)
+#define UA_CONTROL_SOFT_RESET		BIT(2)
+
+#define UA_STATUS			0x02
+#define UA_STATUS_PARITY_ERR		BIT(0)
+#define UA_STATUS_FRAME_ERR		BIT(1)
+#define UA_STATUS_OVERRUN_ERR		BIT(2)
+#define UA_STATUS_TX_READY		BIT(6)
+
+#define UA_CONFIG			0x03
+#define UA_CONFIG_CHAR_LEN		BIT(0)
+#define UA_CONFIG_STOP_BITS		BIT(1)
+#define UA_CONFIG_PARITY		BIT(2)
+#define UA_CONFIG_ODD_PARITY		BIT(4)
+
+#define UA_EMI_REC			0x04
+
+#define UA_HBAUD_LO			0x08
+#define UA_HBAUD_HI			0x09
+
+#define UA_STATUS_FIFO			0x0a
+#define UA_STATUS_FIFO_RX_EMPTY		BIT(2)
+#define UA_STATUS_FIFO_RX_INT_ALMOST	BIT(3)
+#define UA_STATUS_FIFO_TX_FULL		BIT(4)
+#define UA_STATUS_FIFO_TX_INT_ALMOST	BIT(7)
+
+#define UA_CONFIG_FIFO			0x0b
+#define UA_CONFIG_FIFO_RX_THRESH	7
+#define UA_CONFIG_FIFO_RX_FIFO_MODE	BIT(3)
+#define UA_CONFIG_FIFO_TX_FIFO_MODE	BIT(7)
+
+#define UA_INTFLAG_CLEAR		0x1c
+#define UA_INTFLAG_SET			0x1d
+#define UA_INT_ENABLE			0x1e
+#define UA_INT_STATUS			0x1f
+
+#define UA_INT_TX			BIT(0)
+#define UA_INT_RX			BIT(1)
+
+#define DIGICOLOR_USART_NR		3
+
+/*
+ * We use the 16 bytes hardware FIFO to buffer Rx traffic. Rx interrupt is
+ * only produced when the FIFO is filled more than a certain configurable
+ * threshold. Unfortunately, there is no way to set this threshold below half
+ * FIFO. This means that we must periodically poll the FIFO status register to
+ * see whether there are waiting Rx bytes.
+ */
+
+struct digicolor_port {
+	struct uart_port port;
+	struct delayed_work rx_poll_work;
+};
+
+static struct uart_port *digicolor_ports[DIGICOLOR_USART_NR];
+
+static bool digicolor_uart_tx_full(struct uart_port *port)
+{
+	return !!(readb_relaxed(port->membase + UA_STATUS_FIFO) &
+		  UA_STATUS_FIFO_TX_FULL);
+}
+
+static bool digicolor_uart_rx_empty(struct uart_port *port)
+{
+	return !!(readb_relaxed(port->membase + UA_STATUS_FIFO) &
+		  UA_STATUS_FIFO_RX_EMPTY);
+}
+
+static void digicolor_uart_stop_tx(struct uart_port *port)
+{
+	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);
+
+	int_enable &= ~UA_INT_TX;
+	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
+}
+
+static void digicolor_uart_start_tx(struct uart_port *port)
+{
+	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);
+
+	int_enable |= UA_INT_TX;
+	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
+}
+
+static void digicolor_uart_stop_rx(struct uart_port *port)
+{
+	u8 int_enable = readb_relaxed(port->membase + UA_INT_ENABLE);
+
+	int_enable &= ~UA_INT_RX;
+	writeb_relaxed(int_enable, port->membase + UA_INT_ENABLE);
+}
+
+static void digicolor_rx_poll(struct work_struct *work)
+{
+	struct digicolor_port *dp =
+		container_of(to_delayed_work(work),
+			     struct digicolor_port, rx_poll_work);
+
+	if (!digicolor_uart_rx_empty(&dp->port))
+		/* force RX interrupt */
+		writeb_relaxed(UA_INT_RX, dp->port.membase + UA_INTFLAG_SET);
+
+	schedule_delayed_work(&dp->rx_poll_work, msecs_to_jiffies(100));
+}
+
+static void digicolor_uart_rx(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	while (1) {
+		u8 status, ch;
+		unsigned int ch_flag;
+
+		if (digicolor_uart_rx_empty(port))
+			break;
+
+		ch = readb_relaxed(port->membase + UA_EMI_REC);
+		status = readb_relaxed(port->membase + UA_STATUS);
+
+		port->icount.rx++;
+		ch_flag = TTY_NORMAL;
+
+		if (status) {
+			if (status & UA_STATUS_PARITY_ERR)
+				port->icount.parity++;
+			else if (status & UA_STATUS_FRAME_ERR)
+				port->icount.frame++;
+			else if (status & UA_STATUS_OVERRUN_ERR)
+				port->icount.overrun++;
+
+			status &= port->read_status_mask;
+
+			if (status & UA_STATUS_PARITY_ERR)
+				ch_flag = TTY_PARITY;
+			else if (status & UA_STATUS_FRAME_ERR)
+				ch_flag = TTY_FRAME;
+			else if (status & UA_STATUS_OVERRUN_ERR)
+				ch_flag = TTY_OVERRUN;
+		}
+
+		if (status & port->ignore_status_mask)
+			continue;
+
+		uart_insert_char(port, status, UA_STATUS_OVERRUN_ERR, ch,
+				 ch_flag);
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void digicolor_uart_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long flags;
+
+	if (digicolor_uart_tx_full(port))
+		return;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (port->x_char) {
+		writeb_relaxed(port->x_char, port->membase + UA_EMI_REC);
+		port->icount.tx++;
+		port->x_char = 0;
+		goto out;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		digicolor_uart_stop_tx(port);
+		goto out;
+	}
+
+	while (!uart_circ_empty(xmit)) {
+		writeb(xmit->buf[xmit->tail], port->membase + UA_EMI_REC);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+
+		if (digicolor_uart_tx_full(port))
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+out:
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static irqreturn_t digicolor_uart_int(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	u8 int_status = readb_relaxed(port->membase + UA_INT_STATUS);
+
+	writeb_relaxed(UA_INT_RX | UA_INT_TX,
+		       port->membase + UA_INTFLAG_CLEAR);
+
+	if (int_status & UA_INT_RX)
+		digicolor_uart_rx(port);
+	if (int_status & UA_INT_TX)
+		digicolor_uart_tx(port);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int digicolor_uart_tx_empty(struct uart_port *port)
+{
+	u8 status = readb_relaxed(port->membase + UA_STATUS);
+
+	return (status & UA_STATUS_TX_READY) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int digicolor_uart_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS;
+}
+
+static void digicolor_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void digicolor_uart_break_ctl(struct uart_port *port, int state)
+{
+}
+
+static int digicolor_uart_startup(struct uart_port *port)
+{
+	struct digicolor_port *dp =
+		container_of(port, struct digicolor_port, port);
+
+	writeb_relaxed(UA_ENABLE_ENABLE, port->membase + UA_ENABLE);
+	writeb_relaxed(UA_CONTROL_SOFT_RESET, port->membase + UA_CONTROL);
+	writeb_relaxed(0, port->membase + UA_CONTROL);
+
+	writeb_relaxed(UA_CONFIG_FIFO_RX_FIFO_MODE
+		       | UA_CONFIG_FIFO_TX_FIFO_MODE | UA_CONFIG_FIFO_RX_THRESH,
+		       port->membase + UA_CONFIG_FIFO);
+	writeb_relaxed(UA_STATUS_FIFO_RX_INT_ALMOST,
+		       port->membase + UA_STATUS_FIFO);
+	writeb_relaxed(UA_CONTROL_RX_ENABLE | UA_CONTROL_TX_ENABLE,
+		       port->membase + UA_CONTROL);
+	writeb_relaxed(UA_INT_TX | UA_INT_RX,
+		       port->membase + UA_INT_ENABLE);
+
+	schedule_delayed_work(&dp->rx_poll_work, msecs_to_jiffies(100));
+
+	return 0;
+}
+
+static void digicolor_uart_shutdown(struct uart_port *port)
+{
+	struct digicolor_port *dp =
+		container_of(port, struct digicolor_port, port);
+
+	writeb_relaxed(0, port->membase + UA_ENABLE);
+	cancel_delayed_work_sync(&dp->rx_poll_work);
+}
+
+static void digicolor_uart_set_termios(struct uart_port *port,
+				       struct ktermios *termios,
+				       struct ktermios *old)
+{
+	unsigned int baud, divisor;
+	u8 config = 0;
+	unsigned long flags;
+
+	/* Mask termios capabilities we don't support */
+	termios->c_cflag &= ~CMSPAR;
+	termios->c_iflag &= ~(BRKINT | IGNBRK);
+
+	/* Limit baud rates so that we don't need the fractional divider */
+	baud = uart_get_baud_rate(port, termios, old,
+				  port->uartclk / (0x10000*16),
+				  port->uartclk / 256);
+	divisor = uart_get_divisor(port, baud) - 1;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS7:
+		break;
+	case CS8:
+	default:
+		config |= UA_CONFIG_CHAR_LEN;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		config |= UA_CONFIG_STOP_BITS;
+
+	if (termios->c_cflag & PARENB) {
+		config |= UA_CONFIG_PARITY;
+		if (termios->c_cflag & PARODD)
+			config |= UA_CONFIG_ODD_PARITY;
+	}
+
+	/* Set read status mask */
+	port->read_status_mask = UA_STATUS_OVERRUN_ERR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UA_STATUS_PARITY_ERR
+			| UA_STATUS_FRAME_ERR;
+
+	/* Set status ignore mask */
+	port->ignore_status_mask = 0;
+	if (!(termios->c_cflag & CREAD))
+		port->ignore_status_mask |= UA_STATUS_OVERRUN_ERR
+			| UA_STATUS_PARITY_ERR | UA_STATUS_FRAME_ERR;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	writeb_relaxed(config, port->membase + UA_CONFIG);
+	writeb_relaxed(divisor & 0xff, port->membase + UA_HBAUD_LO);
+	writeb_relaxed(divisor >> 8, port->membase + UA_HBAUD_HI);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *digicolor_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_DIGICOLOR) ? "DIGICOLOR USART" : NULL;
+}
+
+static void digicolor_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_DIGICOLOR;
+}
+
+static void digicolor_uart_release_port(struct uart_port *port)
+{
+}
+
+static int digicolor_uart_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static const struct uart_ops digicolor_uart_ops = {
+	.tx_empty	= digicolor_uart_tx_empty,
+	.set_mctrl	= digicolor_uart_set_mctrl,
+	.get_mctrl	= digicolor_uart_get_mctrl,
+	.stop_tx	= digicolor_uart_stop_tx,
+	.start_tx	= digicolor_uart_start_tx,
+	.stop_rx	= digicolor_uart_stop_rx,
+	.break_ctl	= digicolor_uart_break_ctl,
+	.startup	= digicolor_uart_startup,
+	.shutdown	= digicolor_uart_shutdown,
+	.set_termios	= digicolor_uart_set_termios,
+	.type		= digicolor_uart_type,
+	.config_port	= digicolor_uart_config_port,
+	.release_port	= digicolor_uart_release_port,
+	.request_port	= digicolor_uart_request_port,
+};
+
+static void digicolor_uart_console_putchar(struct uart_port *port, int ch)
+{
+	while (digicolor_uart_tx_full(port))
+		cpu_relax();
+
+	writeb_relaxed(ch, port->membase + UA_EMI_REC);
+}
+
+static void digicolor_uart_console_write(struct console *co, const char *c,
+					 unsigned n)
+{
+	struct uart_port *port = digicolor_ports[co->index];
+	u8 status;
+	unsigned long flags;
+	int locked = 1;
+
+	if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	uart_console_write(port, c, n, digicolor_uart_console_putchar);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Wait for transmitter to become empty */
+	do {
+		status = readb_relaxed(port->membase + UA_STATUS);
+	} while ((status & UA_STATUS_TX_READY) == 0);
+}
+
+static int digicolor_uart_console_setup(struct console *co, char *options)
+{
+	int baud = 115200, bits = 8, parity = 'n', flow = 'n';
+	struct uart_port *port;
+
+	if (co->index < 0 || co->index >= DIGICOLOR_USART_NR)
+		return -EINVAL;
+
+	port = digicolor_ports[co->index];
+	if (!port)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console digicolor_console = {
+	.name	= "ttyS",
+	.device	= uart_console_device,
+	.write	= digicolor_uart_console_write,
+	.setup	= digicolor_uart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+static struct uart_driver digicolor_uart = {
+	.driver_name	= "digicolor-usart",
+	.dev_name	= "ttyS",
+	.nr		= DIGICOLOR_USART_NR,
+};
+
+static int digicolor_uart_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int ret, index;
+	struct digicolor_port *dp;
+	struct resource *res;
+	struct clk *uart_clk;
+
+	if (!np) {
+		dev_err(&pdev->dev, "Missing device tree node\n");
+		return -ENXIO;
+	}
+
+	index = of_alias_get_id(np, "serial");
+	if (index < 0 || index >= DIGICOLOR_USART_NR)
+		return -EINVAL;
+
+	dp = devm_kzalloc(&pdev->dev, sizeof(*dp), GFP_KERNEL);
+	if (!dp)
+		return -ENOMEM;
+
+	uart_clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(uart_clk))
+		return PTR_ERR(uart_clk);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dp->port.mapbase = res->start;
+	dp->port.membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dp->port.membase))
+		return PTR_ERR(dp->port.membase);
+
+	dp->port.irq = platform_get_irq(pdev, 0);
+	if (IS_ERR_VALUE(dp->port.irq))
+		return dp->port.irq;
+
+	dp->port.iotype = UPIO_MEM;
+	dp->port.uartclk = clk_get_rate(uart_clk);
+	dp->port.fifosize = 16;
+	dp->port.dev = &pdev->dev;
+	dp->port.ops = &digicolor_uart_ops;
+	dp->port.line = index;
+	dp->port.type = PORT_DIGICOLOR;
+	spin_lock_init(&dp->port.lock);
+
+	digicolor_ports[index] = &dp->port;
+	platform_set_drvdata(pdev, &dp->port);
+
+	INIT_DELAYED_WORK(&dp->rx_poll_work, digicolor_rx_poll);
+
+	ret = devm_request_irq(&pdev->dev, dp->port.irq, digicolor_uart_int, 0,
+			       dev_name(&pdev->dev), &dp->port);
+	if (ret)
+		return ret;
+
+	return uart_add_one_port(&digicolor_uart, &dp->port);
+}
+
+static int digicolor_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&digicolor_uart, port);
+
+	return 0;
+}
+
+static const struct of_device_id digicolor_uart_dt_ids[] = {
+	{ .compatible = "cnxt,cx92755-usart", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, digicolor_uart_dt_ids);
+
+static struct platform_driver digicolor_uart_platform = {
+	.driver = {
+		.name		= "digicolor-usart",
+		.of_match_table	= of_match_ptr(digicolor_uart_dt_ids),
+	},
+	.probe	= digicolor_uart_probe,
+	.remove	= digicolor_uart_remove,
+};
+
+static int __init digicolor_uart_init(void)
+{
+	int ret;
+
+	if (IS_ENABLED(CONFIG_SERIAL_CONEXANT_DIGICOLOR_CONSOLE)) {
+		digicolor_uart.cons = &digicolor_console;
+		digicolor_console.data = &digicolor_uart;
+	}
+
+	ret = uart_register_driver(&digicolor_uart);
+	if (ret)
+		return ret;
+
+	return platform_driver_register(&digicolor_uart_platform);
+}
+module_init(digicolor_uart_init);
+
+static void __exit digicolor_uart_exit(void)
+{
+	platform_driver_unregister(&digicolor_uart_platform);
+	uart_unregister_driver(&digicolor_uart);
+}
+module_exit(digicolor_uart_exit);
+
+MODULE_AUTHOR("Baruch Siach <[e-mail]>");
+MODULE_DESCRIPTION("Conexant Digicolor USART serial driver");
+MODULE_LICENSE("GPL");

drivers/tty/serial/etraxfs-uart.c

···
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/tty_flip.h>
+#include <linux/of.h>
+#include <linux/gpio.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <hwregs/ser_defs.h>
+
+#define DRV_NAME "etraxfs-uart"
+#define UART_NR CONFIG_ETRAX_SERIAL_PORTS
+
+#define MODIFY_REG(instance, reg, var)				\
+	do {							\
+		if (REG_RD_INT(ser, instance, reg) !=		\
+		    REG_TYPE_CONV(int, reg_ser_##reg, var))	\
+			REG_WR(ser, instance, reg, var);	\
+	} while (0)
+
+struct uart_cris_port {
+	struct uart_port port;
+
+	int initialized;
+	int irq;
+
+	void __iomem *regi_ser;
+
+	struct gpio_desc *dtr_pin;
+	struct gpio_desc *dsr_pin;
+	struct gpio_desc *ri_pin;
+	struct gpio_desc *cd_pin;
+
+	int write_ongoing;
+};
+
+static struct uart_driver etraxfs_uart_driver;
+static struct uart_port *console_port;
+static int console_baud = 115200;
+static struct uart_cris_port *etraxfs_uart_ports[UART_NR];
+
+static void cris_serial_port_init(struct uart_port *port, int line);
+static void etraxfs_uart_stop_rx(struct uart_port *port);
+static inline void etraxfs_uart_start_tx_bottom(struct uart_port *port);
+
+#ifdef CONFIG_SERIAL_ETRAXFS_CONSOLE
+static void
+cris_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_cris_port *up;
+	int i;
+	reg_ser_r_stat_din stat;
+	reg_ser_rw_tr_dma_en tr_dma_en, old;
+
+	up = etraxfs_uart_ports[co->index];
+
+	if (!up)
+		return;
+
+	/* Switch to manual mode. */
+	tr_dma_en = old = REG_RD(ser, up->regi_ser, rw_tr_dma_en);
+	if (tr_dma_en.en == regk_ser_yes) {
+		tr_dma_en.en = regk_ser_no;
+		REG_WR(ser, up->regi_ser, rw_tr_dma_en, tr_dma_en);
+	}
+
+	/* Send data. */
+	for (i = 0; i < count; i++) {
+		/* LF -> CRLF */
+		if (s[i] == '\n') {
+			do {
+				stat = REG_RD(ser, up->regi_ser, r_stat_din);
+			} while (!stat.tr_rdy);
+			REG_WR_INT(ser, up->regi_ser, rw_dout, '\r');
+		}
+		/* Wait until transmitter is ready and send. */
+		do {
+			stat = REG_RD(ser, up->regi_ser, r_stat_din);
+		} while (!stat.tr_rdy);
+		REG_WR_INT(ser, up->regi_ser, rw_dout, s[i]);
+	}
+
+	/* Restore mode. */
+	if (tr_dma_en.en != old.en)
+		REG_WR(ser, up->regi_ser, rw_tr_dma_en, old);
+}
+
+static int __init
+cris_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= UART_NR)
+		co->index = 0;
+	port = &etraxfs_uart_ports[co->index]->port;
+	console_port = port;
+
+	co->flags |= CON_CONSDEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	console_baud = baud;
+	cris_serial_port_init(port, co->index);
+	uart_set_options(port, co, baud, parity, bits, flow);
+
+	return 0;
+}
+
+static struct tty_driver *cris_console_device(struct console *co, int *index)
+{
+	struct uart_driver *p = co->data;
+	*index = co->index;
+	return p->tty_driver;
+}
+
+static struct console cris_console = {
+	.name = "ttyS",
+	.write = cris_console_write,
+	.device = cris_console_device,
+	.setup = cris_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &etraxfs_uart_driver,
+};
+#endif /* CONFIG_SERIAL_ETRAXFS_CONSOLE */
+
+static struct uart_driver etraxfs_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "serial",
+	.dev_name = "ttyS",
+	.major = TTY_MAJOR,
+	.minor = 64,
+	.nr = UART_NR,
+#ifdef CONFIG_SERIAL_ETRAXFS_CONSOLE
+	.cons = &cris_console,
+#endif /* CONFIG_SERIAL_ETRAXFS_CONSOLE */
+};
+
+static inline int crisv32_serial_get_rts(struct uart_cris_port *up)
+{
+	void __iomem *regi_ser = up->regi_ser;
+	/*
+	 * Return what the user has controlled rts to or
+	 * what the pin is? (if auto_rts is used it differs during tx)
+	 */
+	reg_ser_r_stat_din rstat = REG_RD(ser, regi_ser, r_stat_din);
+
+	return !(rstat.rts_n == regk_ser_active);
+}
+
+/*
+ * A set = 0 means 3.3V on the pin, bitvalue: 0=active, 1=inactive
+ *                                            0=0V    , 1=3.3V
+ */
+static inline void crisv32_serial_set_rts(struct uart_cris_port *up,
+					  int set, int force)
+{
+	void __iomem *regi_ser = up->regi_ser;
+
+	unsigned long flags;
+	reg_ser_rw_rec_ctrl rec_ctrl;
+
+	local_irq_save(flags);
+	rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl);
+
+	if (set)
+		rec_ctrl.rts_n = regk_ser_active;
+	else
+		rec_ctrl.rts_n = regk_ser_inactive;
+	REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl);
+	local_irq_restore(flags);
+}
+
+static inline int crisv32_serial_get_cts(struct uart_cris_port *up)
+{
+	void __iomem *regi_ser = up->regi_ser;
+	reg_ser_r_stat_din rstat = REG_RD(ser, regi_ser, r_stat_din);
+
+	return (rstat.cts_n == regk_ser_active);
+}
+
+/*
+ * Send a single character for XON/XOFF purposes.  We do it in this separate
+ * function instead of the alternative support port.x_char, in the ...start_tx
+ * function, so we don't mix up this case with possibly enabling transmission
+ * of queued-up data (in case that's disabled after *receiving* an XOFF or
+ * negative CTS).  This function is used for both DMA and non-DMA case; see HW
+ * docs specifically blessing sending characters manually when DMA for
+ * transmission is enabled and running.  We may be asked to transmit despite
+ * the transmitter being disabled by a ..._stop_tx call so we need to enable
+ * it temporarily but restore the state afterwards.
+ */
+static void etraxfs_uart_send_xchar(struct uart_port *port, char ch)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	reg_ser_rw_dout dout = { .data = ch };
+	reg_ser_rw_ack_intr ack_intr = { .tr_rdy = regk_ser_yes };
+	reg_ser_r_stat_din rstat;
+	reg_ser_rw_tr_ctrl prev_tr_ctrl, tr_ctrl;
+	void __iomem *regi_ser = up->regi_ser;
+	unsigned long flags;
+
+	/*
+	 * Wait for tr_rdy in case a character is already being output.  Make
+	 * sure we have integrity between the register reads and the writes
+	 * below, but don't busy-wait with interrupts off and the port lock
+	 * taken.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+	do {
+		spin_unlock_irqrestore(&port->lock, flags);
+		spin_lock_irqsave(&port->lock, flags);
+		prev_tr_ctrl = tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
+		rstat = REG_RD(ser, regi_ser, r_stat_din);
+	} while (!rstat.tr_rdy);
+
+	/*
+	 * Ack an interrupt if one was just issued for the previous character
+	 * that was output.  This is required for non-DMA as the interrupt is
+	 * used as the only indicator that the transmitter is ready and it
+	 * isn't while this x_char is being transmitted.
+	 */
+	REG_WR(ser, regi_ser, rw_ack_intr, ack_intr);
+
+	/* Enable the transmitter in case it was disabled. */
+	tr_ctrl.stop = 0;
+	REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
+
+	/*
+	 * Finally, send the blessed character; nothing should stop it now,
+	 * except for an xoff-detected state, which we'll handle below.
+	 */
+	REG_WR(ser, regi_ser, rw_dout, dout);
+	up->port.icount.tx++;
+
+	/* There might be an xoff state to clear. */
+	rstat = REG_RD(ser, up->regi_ser, r_stat_din);
+
+	/*
+	 * Clear any xoff state that *may* have been there to
+	 * inhibit transmission of the character.
+	 */
+	if (rstat.xoff_detect) {
+		reg_ser_rw_xoff_clr xoff_clr = { .clr = 1 };
+		reg_ser_rw_tr_dma_en tr_dma_en;
+
+		REG_WR(ser, regi_ser, rw_xoff_clr, xoff_clr);
+		tr_dma_en = REG_RD(ser, regi_ser, rw_tr_dma_en);
+
+		/*
+		 * If we had an xoff state but cleared it, instead sneak in a
+		 * disabled state for the transmitter, after the character we
+		 * sent.  Thus we keep the port disabled, just as if the xoff
+		 * state was still in effect (or actually, as if stop_tx had
+		 * been called, as we stop DMA too).
+		 */
+		prev_tr_ctrl.stop = 1;
+
+		tr_dma_en.en = 0;
+		REG_WR(ser, regi_ser, rw_tr_dma_en, tr_dma_en);
+	}
+
+	/* Restore "previous" enabled/disabled state of the transmitter. */
+	REG_WR(ser, regi_ser, rw_tr_ctrl, prev_tr_ctrl);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * Do not spin_lock_irqsave or disable interrupts by other means here; it's
+ * already done by the caller.
+ */
+static void etraxfs_uart_start_tx(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+
+	/* we have already done below if a write is ongoing */
+	if (up->write_ongoing)
+		return;
+
+	/* Signal that write is ongoing */
+	up->write_ongoing = 1;
+
+	etraxfs_uart_start_tx_bottom(port);
+}
+
+static inline void etraxfs_uart_start_tx_bottom(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	void __iomem *regi_ser = up->regi_ser;
+	reg_ser_rw_tr_ctrl tr_ctrl;
+	reg_ser_rw_intr_mask intr_mask;
+
+	tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
+	tr_ctrl.stop = regk_ser_no;
+	REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
+	intr_mask = REG_RD(ser, regi_ser, rw_intr_mask);
+	intr_mask.tr_rdy = regk_ser_yes;
+	REG_WR(ser, regi_ser, rw_intr_mask, intr_mask);
+}
+
+/*
+ * This function handles both the DMA and non-DMA case by ordering the
+ * transmitter to stop of after the current character.  We don't need to wait
+ * for any such character to be completely transmitted; we do that where it
+ * matters, like in etraxfs_uart_set_termios.  Don't busy-wait here; see
+ * Documentation/serial/driver: this function is called within
+ * spin_lock_irq{,save} and thus separate ones would be disastrous (when SMP).
+ * There's no documented need to set the txd pin to any particular value;
+ * break setting is controlled solely by etraxfs_uart_break_ctl.
+ */
+static void etraxfs_uart_stop_tx(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	void __iomem *regi_ser = up->regi_ser;
+	reg_ser_rw_tr_ctrl tr_ctrl;
+	reg_ser_rw_intr_mask intr_mask;
+	reg_ser_rw_tr_dma_en tr_dma_en = {0};
+	reg_ser_rw_xoff_clr xoff_clr = {0};
+
+	/*
+	 * For the non-DMA case, we'd get a tr_rdy interrupt that we're not
+	 * interested in as we're not transmitting any characters.  For the
+	 * DMA case, that interrupt is already turned off, but no reason to
+	 * waste code on conditionals here.
+	 */
+	intr_mask = REG_RD(ser, regi_ser, rw_intr_mask);
+	intr_mask.tr_rdy = regk_ser_no;
+	REG_WR(ser, regi_ser, rw_intr_mask, intr_mask);
+
+	tr_ctrl = REG_RD(ser, regi_ser, rw_tr_ctrl);
+	tr_ctrl.stop = 1;
+	REG_WR(ser, regi_ser, rw_tr_ctrl, tr_ctrl);
+
+	/*
+	 * Always clear possible hardware xoff-detected state here, no need to
+	 * unnecessary consider mctrl settings and when they change.  We clear
+	 * it here rather than in start_tx: both functions are called as the
+	 * effect of XOFF processing, but start_tx is also called when upper
+	 * levels tell the driver that there are more characters to send, so
+	 * avoid adding code there.
+	 */
+	xoff_clr.clr = 1;
+	REG_WR(ser, regi_ser, rw_xoff_clr, xoff_clr);
+
+	/*
+	 * Disable transmitter DMA, so that if we're in XON/XOFF, we can send
+	 * those single characters without also giving go-ahead for queued up
+	 * DMA data.
+	 */
+	tr_dma_en.en = 0;
+	REG_WR(ser, regi_ser, rw_tr_dma_en, tr_dma_en);
+
+	/*
+	 * Make sure that write_ongoing is reset when stopping tx.
+	 */
+	up->write_ongoing = 0;
+}
+
+static void etraxfs_uart_stop_rx(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	void __iomem *regi_ser = up->regi_ser;
+	reg_ser_rw_rec_ctrl rec_ctrl = REG_RD(ser, regi_ser, rw_rec_ctrl);
+
+	rec_ctrl.en = regk_ser_no;
+	REG_WR(ser, regi_ser, rw_rec_ctrl, rec_ctrl);
+}
+
+static void etraxfs_uart_enable_ms(struct uart_port *port)
+{
+}
+
+static void check_modem_status(struct uart_cris_port *up)
+{
+}
+
+static unsigned int etraxfs_uart_tx_empty(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	unsigned long flags;
+	unsigned int ret;
+	reg_ser_r_stat_din rstat = {0};
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	rstat = REG_RD(ser, up->regi_ser, r_stat_din);
+	ret = rstat.tr_empty ? TIOCSER_TEMT : 0;
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	return ret;
+}
+static unsigned int etraxfs_uart_get_mctrl(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	unsigned int ret;
+
+	ret = 0;
+	if (crisv32_serial_get_rts(up))
+		ret |= TIOCM_RTS;
+	/* DTR is active low */
+	if (up->dtr_pin && !gpiod_get_raw_value(up->dtr_pin))
+		ret |= TIOCM_DTR;
+	/* CD is active low */
+	if (up->cd_pin && !gpiod_get_raw_value(up->cd_pin))
+		ret |= TIOCM_CD;
+	/* RI is active low */
+	if (up->ri_pin && !gpiod_get_raw_value(up->ri_pin))
+		ret |= TIOCM_RI;
+	/* DSR is active low */
+	if (up->dsr_pin && !gpiod_get_raw_value(up->dsr_pin))
+		ret |= TIOCM_DSR;
+	if (crisv32_serial_get_cts(up))
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void etraxfs_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+
+	crisv32_serial_set_rts(up, mctrl & TIOCM_RTS ? 1 : 0, 0);
+	/* DTR is active low */
+	if (up->dtr_pin)
+		gpiod_set_raw_value(up->dtr_pin, mctrl & TIOCM_DTR ? 0 : 1);
+	/* RI is active low */
+	if (up->ri_pin)
+		gpiod_set_raw_value(up->ri_pin, mctrl & TIOCM_RNG ? 0 : 1);
+	/* CD is active low */
+	if (up->cd_pin)
+		gpiod_set_raw_value(up->cd_pin, mctrl & TIOCM_CD ? 0 : 1);
+}
+
+static void etraxfs_uart_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	unsigned long flags;
+	reg_ser_rw_tr_ctrl tr_ctrl;
+	reg_ser_rw_tr_dma_en tr_dma_en;
+	reg_ser_rw_intr_mask intr_mask;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	tr_ctrl = REG_RD(ser, up->regi_ser, rw_tr_ctrl);
+	tr_dma_en = REG_RD(ser, up->regi_ser, rw_tr_dma_en);
+	intr_mask = REG_RD(ser, up->regi_ser, rw_intr_mask);
+
+	if (break_state != 0) { /* Send break */
+		/*
+		 * We need to disable DMA (if used) or tr_rdy interrupts if no
+		 * DMA.  No need to make this conditional on use of DMA;
+		 * disabling will be a no-op for the other mode.
+		 */
+		intr_mask.tr_rdy = regk_ser_no;
+		tr_dma_en.en = 0;
+
+		/*
+		 * Stop transmission and set the txd pin to 0 after the
+		 * current character.  The txd setting will take effect after
+		 * any current transmission has completed.
+		 */
+		tr_ctrl.stop = 1;
+		tr_ctrl.txd = 0;
+	} else {
+		/* Re-enable the serial interrupt. */
+		intr_mask.tr_rdy = regk_ser_yes;
+
+		tr_ctrl.stop = 0;
+		tr_ctrl.txd = 1;
+	}
+	REG_WR(ser, up->regi_ser, rw_tr_ctrl, tr_ctrl);
+	REG_WR(ser, up->regi_ser, rw_tr_dma_en, tr_dma_en);
+	REG_WR(ser, up->regi_ser, rw_intr_mask, intr_mask);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void
+transmit_chars_no_dma(struct uart_cris_port *up)
+{
+	int max_count;
+	struct circ_buf *xmit = &up->port.state->xmit;
+
+	void __iomem *regi_ser = up->regi_ser;
+	reg_ser_r_stat_din rstat;
+	reg_ser_rw_ack_intr ack_intr = { .tr_rdy = regk_ser_yes };
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
+		/* No more to send, so disable the interrupt. */
+		reg_ser_rw_intr_mask intr_mask;
+
+		intr_mask = REG_RD(ser, regi_ser, rw_intr_mask);
+		intr_mask.tr_rdy = 0;
+		intr_mask.tr_empty = 0;
+		REG_WR(ser, regi_ser, rw_intr_mask, intr_mask);
+		up->write_ongoing = 0;
+		return;
+	}
+
+	/* If the serport is fast, we send up to max_count bytes before
+	   exiting the loop.  */
+	max_count = 64;
+	do {
+		reg_ser_rw_dout dout = { .data = xmit->buf[xmit->tail] };
+
+		REG_WR(ser, regi_ser, rw_dout, dout);
+		REG_WR(ser, regi_ser, rw_ack_intr, ack_intr);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
+		up->port.icount.tx++;
+		if (xmit->head == xmit->tail)
+			break;
+		rstat = REG_RD(ser, regi_ser, r_stat_din);
+	} while ((--max_count > 0) && rstat.tr_rdy);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+}
+
+static void receive_chars_no_dma(struct uart_cris_port *up)
+{
+	reg_ser_rs_stat_din stat_din;
+	reg_ser_r_stat_din rstat;
+	struct tty_port *port;
+	struct uart_icount *icount;
+	int max_count = 16;
+	char flag;
+	reg_ser_rw_ack_intr ack_intr = { 0 };
+
+	rstat = REG_RD(ser, up->regi_ser, r_stat_din);
+	icount = &up->port.icount;
+	port = &up->port.state->port;
+
+	do {
+		stat_din = REG_RD(ser, up->regi_ser, rs_stat_din);
+
+		flag = TTY_NORMAL;
+		ack_intr.dav = 1;
+		REG_WR(ser, up->regi_ser, rw_ack_intr, ack_intr);
+		icount->rx++;
+
+		if (stat_din.framing_err | stat_din.par_err | stat_din.orun) {
+			if (stat_din.data == 0x00 &&
+			    stat_din.framing_err) {
+				/* Most likely a break. */
+				flag = TTY_BREAK;
+				icount->brk++;
+			} else if (stat_din.par_err) {
+				flag = TTY_PARITY;
+				icount->parity++;
+			} else if (stat_din.orun) {
+				flag = TTY_OVERRUN;
+				icount->overrun++;
+			} else if (stat_din.framing_err) {
+				flag = TTY_FRAME;
+				icount->frame++;
+			}
+		}
+
+		/*
+		 * If this becomes important, we probably *could* handle this
+		 * gracefully by keeping track of the unhandled character.
+		 */
+		if (!tty_insert_flip_char(port, stat_din.data, flag))
+			panic("%s: No tty buffer space", __func__);
+		rstat = REG_RD(ser, up->regi_ser, r_stat_din);
+	} while (rstat.dav && (max_count-- > 0));
+	spin_unlock(&up->port.lock);
+	tty_flip_buffer_push(port);
+	spin_lock(&up->port.lock);
+}
+
+static irqreturn_t
+ser_interrupt(int irq, void *dev_id)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)dev_id;
+	void __iomem *regi_ser;
+	int handled = 0;
+
+	spin_lock(&up->port.lock);
+
+	regi_ser = up->regi_ser;
+
+	if (regi_ser) {
+		reg_ser_r_masked_intr masked_intr;
+
+		masked_intr = REG_RD(ser, regi_ser, r_masked_intr);
+		/*
+		 * Check what interrupts are active before taking
+		 * actions. If DMA is used the interrupt shouldn't
+		 * be enabled.
+		 */
+		if (masked_intr.dav) {
+			receive_chars_no_dma(up);
+			handled = 1;
+		}
+		check_modem_status(up);
+
+		if (masked_intr.tr_rdy) {
+			transmit_chars_no_dma(up);
+			handled = 1;
+		}
+	}
+	spin_unlock(&up->port.lock);
+	return IRQ_RETVAL(handled);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int etraxfs_uart_get_poll_char(struct uart_port *port)
+{
+	reg_ser_rs_stat_din stat;
+	reg_ser_rw_ack_intr ack_intr = { 0 };
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+
+	do {
+		stat = REG_RD(ser, up->regi_ser, rs_stat_din);
+	} while (!stat.dav);
+
+	/* Ack the data_avail interrupt. */
+	ack_intr.dav = 1;
+	REG_WR(ser, up->regi_ser, rw_ack_intr, ack_intr);
+
+	return stat.data;
+}
+
+static void etraxfs_uart_put_poll_char(struct uart_port *port,
+					unsigned char c)
+{
+	reg_ser_r_stat_din stat;
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+
+	do {
+		stat = REG_RD(ser, up->regi_ser, r_stat_din);
+	} while (!stat.tr_rdy);
+	REG_WR_INT(ser, up->regi_ser, rw_dout, c);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+static int etraxfs_uart_startup(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	unsigned long flags;
+	reg_ser_rw_intr_mask ser_intr_mask = {0};
+
+	ser_intr_mask.dav = regk_ser_yes;
+
+	if (request_irq(etraxfs_uart_ports[port->line]->irq, ser_interrupt,
+			0, DRV_NAME, etraxfs_uart_ports[port->line]))
+		panic("irq ser%d", port->line);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	REG_WR(ser, up->regi_ser, rw_intr_mask, ser_intr_mask);
+
+	etraxfs_uart_set_mctrl(&up->port, up->port.mctrl);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return 0;
+}
+
+static void etraxfs_uart_shutdown(struct uart_port *port)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	etraxfs_uart_stop_tx(port);
+	etraxfs_uart_stop_rx(port);
+
+	free_irq(etraxfs_uart_ports[port->line]->irq,
+		 etraxfs_uart_ports[port->line]);
+
+	etraxfs_uart_set_mctrl(&up->port, up->port.mctrl);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+}
+
+static void
+etraxfs_uart_set_termios(struct uart_port *port, struct ktermios *termios,
+			 struct ktermios *old)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+	unsigned long flags;
+	reg_ser_rw_xoff xoff;
+	reg_ser_rw_xoff_clr xoff_clr = {0};
+	reg_ser_rw_tr_ctrl tx_ctrl = {0};
+	reg_ser_rw_tr_dma_en tx_dma_en = {0};
+	reg_ser_rw_rec_ctrl rx_ctrl = {0};
+	reg_ser_rw_tr_baud_div tx_baud_div = {0};
+	reg_ser_rw_rec_baud_div rx_baud_div = {0};
+	int baud;
+
+	if (old &&
+	    termios->c_cflag == old->c_cflag &&
+	    termios->c_iflag == old->c_iflag)
+		return;
+
+	/* Tx: 8 bit, no/even parity, 1 stop bit, no cts. */
+	tx_ctrl.base_freq = regk_ser_f29_493;
+	tx_ctrl.en = 0;
+	tx_ctrl.stop = 0;
+	tx_ctrl.auto_rts = regk_ser_no;
+	tx_ctrl.txd = 1;
+	tx_ctrl.auto_cts = 0;
+	/* Rx: 8 bit, no/even parity. */
+	rx_ctrl.dma_err = regk_ser_stop;
+	rx_ctrl.sampling = regk_ser_majority;
+	rx_ctrl.timeout = 1;
+
+	rx_ctrl.rts_n = regk_ser_inactive;
+
+	/* Common for tx and rx: 8N1. */
+	tx_ctrl.data_bits = regk_ser_bits8;
+	rx_ctrl.data_bits = regk_ser_bits8;
+	tx_ctrl.par = regk_ser_even;
+	rx_ctrl.par = regk_ser_even;
+	tx_ctrl.par_en = regk_ser_no;
+	rx_ctrl.par_en = regk_ser_no;
+
+	tx_ctrl.stop_bits = regk_ser_bits1;
+
+	/*
+	 * Change baud-rate and write it to the hardware.
+	 *
+	 * baud_clock = base_freq / (divisor*8)
+	 * divisor = base_freq / (baud_clock * 8)
+	 * base_freq is either:
+	 * off, ext, 29.493MHz, 32.000 MHz, 32.768 MHz or 100 MHz
+	 * 20.493MHz is used for standard baudrates
+	 */
+
+	/*
+	 * For the console port we keep the original baudrate here.  Not very
+	 * beautiful.
+	 */
+	if ((port != console_port) || old)
+		baud = uart_get_baud_rate(port, termios, old, 0,
+					  port->uartclk / 8);
+	else
+		baud = console_baud;
+
+	tx_baud_div.div = 29493000 / (8 * baud);
+	/* Rx uses same as tx. */
+	rx_baud_div.div = tx_baud_div.div;
+	rx_ctrl.base_freq = tx_ctrl.base_freq;
+
+	if ((termios->c_cflag & CSIZE) == CS7) {
+		/* Set 7 bit mode. */
+		tx_ctrl.data_bits = regk_ser_bits7;
+		rx_ctrl.data_bits = regk_ser_bits7;
+	}
+
+	if (termios->c_cflag & CSTOPB) {
+		/* Set 2 stop bit mode. */
+		tx_ctrl.stop_bits = regk_ser_bits2;
+	}
+
+	if (termios->c_cflag & PARENB) {
+		/* Enable parity. */
+		tx_ctrl.par_en = regk_ser_yes;
+		rx_ctrl.par_en = regk_ser_yes;
+	}
+
+	if (termios->c_cflag & CMSPAR) {
+		if (termios->c_cflag & PARODD) {
+			/* Set mark parity if PARODD and CMSPAR. */
+			tx_ctrl.par = regk_ser_mark;
+			rx_ctrl.par = regk_ser_mark;
+		} else {
+			tx_ctrl.par = regk_ser_space;
+			rx_ctrl.par = regk_ser_space;
+		}
+	} else {
+		if (termios->c_cflag & PARODD) {
+			/* Set odd parity. */
+		       tx_ctrl.par = regk_ser_odd;
+		       rx_ctrl.par = regk_ser_odd;
+		}
+	}
+
+	if (termios->c_cflag & CRTSCTS) {
+		/* Enable automatic CTS handling. */
+		tx_ctrl.auto_cts = regk_ser_yes;
+	}
+
+	/* Make sure the tx and rx are enabled. */
+	tx_ctrl.en = regk_ser_yes;
+	rx_ctrl.en = regk_ser_yes;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	tx_dma_en.en = 0;
+	REG_WR(ser, up->regi_ser, rw_tr_dma_en, tx_dma_en);
+
+	/* Actually write the control regs (if modified) to the hardware. */
+	uart_update_timeout(port, termios->c_cflag, port->uartclk/8);
+	MODIFY_REG(up->regi_ser, rw_rec_baud_div, rx_baud_div);
+	MODIFY_REG(up->regi_ser, rw_rec_ctrl, rx_ctrl);
+
+	MODIFY_REG(up->regi_ser, rw_tr_baud_div, tx_baud_div);
+	MODIFY_REG(up->regi_ser, rw_tr_ctrl, tx_ctrl);
+
+	tx_dma_en.en = 0;
+	REG_WR(ser, up->regi_ser, rw_tr_dma_en, tx_dma_en);
+
+	xoff = REG_RD(ser, up->regi_ser, rw_xoff);
+
+	if (up->port.state && up->port.state->port.tty &&
+	    (up->port.state->port.tty->termios.c_iflag & IXON)) {
+		xoff.chr = STOP_CHAR(up->port.state->port.tty);
+		xoff.automatic = regk_ser_yes;
+	} else
+		xoff.automatic = regk_ser_no;
+
+	MODIFY_REG(up->regi_ser, rw_xoff, xoff);
+
+	/*
+	 * Make sure we don't start in an automatically shut-off state due to
+	 * a previous early exit.
+	 */
+	xoff_clr.clr = 1;
+	REG_WR(ser, up->regi_ser, rw_xoff_clr, xoff_clr);
+
+	etraxfs_uart_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *
+etraxfs_uart_type(struct uart_port *port)
+{
+	return "CRISv32";
+}
+
+static void etraxfs_uart_release_port(struct uart_port *port)
+{
+}
+
+static int etraxfs_uart_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void etraxfs_uart_config_port(struct uart_port *port, int flags)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+
+	up->port.type = PORT_CRIS;
+}
+
+static const struct uart_ops etraxfs_uart_pops = {
+	.tx_empty = etraxfs_uart_tx_empty,
+	.set_mctrl = etraxfs_uart_set_mctrl,
+	.get_mctrl = etraxfs_uart_get_mctrl,
+	.stop_tx = etraxfs_uart_stop_tx,
+	.start_tx = etraxfs_uart_start_tx,
+	.send_xchar = etraxfs_uart_send_xchar,
+	.stop_rx = etraxfs_uart_stop_rx,
+	.enable_ms = etraxfs_uart_enable_ms,
+	.break_ctl = etraxfs_uart_break_ctl,
+	.startup = etraxfs_uart_startup,
+	.shutdown = etraxfs_uart_shutdown,
+	.set_termios = etraxfs_uart_set_termios,
+	.type = etraxfs_uart_type,
+	.release_port = etraxfs_uart_release_port,
+	.request_port = etraxfs_uart_request_port,
+	.config_port = etraxfs_uart_config_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = etraxfs_uart_get_poll_char,
+	.poll_put_char = etraxfs_uart_put_poll_char,
+#endif
+};
+
+static void cris_serial_port_init(struct uart_port *port, int line)
+{
+	struct uart_cris_port *up = (struct uart_cris_port *)port;
+
+	if (up->initialized)
+		return;
+	up->initialized = 1;
+	port->line = line;
+	spin_lock_init(&port->lock);
+	port->ops = &etraxfs_uart_pops;
+	port->irq = up->irq;
+	port->iobase = (unsigned long) up->regi_ser;
+	port->uartclk = 29493000;
+
+	/*
+	 * We can't fit any more than 255 here (unsigned char), though
+	 * actually UART_XMIT_SIZE characters could be pending output.
+	 * At time of this writing, the definition of "fifosize" is here the
+	 * amount of characters that can be pending output after a start_tx call
+	 * until tx_empty returns 1: see serial_core.c:uart_wait_until_sent.
+	 * This matters for timeout calculations unfortunately, but keeping
+	 * larger amounts at the DMA wouldn't win much so let's just play nice.
+	 */
+	port->fifosize = 255;
+	port->flags = UPF_BOOT_AUTOCONF;
+}
+
+static int etraxfs_uart_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct uart_cris_port *up;
+	int dev_id;
+
+	if (!np)
+		return -ENODEV;
+
+	dev_id = of_alias_get_id(np, "serial");
+	if (dev_id < 0)
+		dev_id = 0;
+
+	if (dev_id >= UART_NR)
+		return -EINVAL;
+
+	if (etraxfs_uart_ports[dev_id])
+		return -EBUSY;
+
+	up = devm_kzalloc(&pdev->dev, sizeof(struct uart_cris_port),
+			  GFP_KERNEL);
+	if (!up)
+		return -ENOMEM;
+
+	up->irq = irq_of_parse_and_map(np, 0);
+	up->regi_ser = of_iomap(np, 0);
+	up->dtr_pin = devm_gpiod_get_optional(&pdev->dev, "dtr");
+	up->dsr_pin = devm_gpiod_get_optional(&pdev->dev, "dsr");
+	up->ri_pin = devm_gpiod_get_optional(&pdev->dev, "ri");
+	up->cd_pin = devm_gpiod_get_optional(&pdev->dev, "cd");
+	up->port.dev = &pdev->dev;
+	cris_serial_port_init(&up->port, dev_id);
+
+	etraxfs_uart_ports[dev_id] = up;
+	platform_set_drvdata(pdev, &up->port);
+	uart_add_one_port(&etraxfs_uart_driver, &up->port);
+
+	return 0;
+}
+
+static int etraxfs_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port;
+
+	port = platform_get_drvdata(pdev);
+	uart_remove_one_port(&etraxfs_uart_driver, port);
+	etraxfs_uart_ports[pdev->id] = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id etraxfs_uart_dt_ids[] = {
+	{ .compatible = "axis,etraxfs-uart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, etraxfs_uart_dt_ids);
+
+static struct platform_driver etraxfs_uart_platform_driver = {
+	.driver = {
+		.name   = DRV_NAME,
+		.of_match_table	= of_match_ptr(etraxfs_uart_dt_ids),
+	},
+	.probe          = etraxfs_uart_probe,
+	.remove         = etraxfs_uart_remove,
+};
+
+static int __init etraxfs_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&etraxfs_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&etraxfs_uart_platform_driver);
+	if (ret)
+		uart_unregister_driver(&etraxfs_uart_driver);
+
+	return ret;
+}
+
+static void __exit etraxfs_uart_exit(void)
+{
+	platform_driver_unregister(&etraxfs_uart_platform_driver);
+	uart_unregister_driver(&etraxfs_uart_driver);
+}
+
+module_init(etraxfs_uart_init);
+module_exit(etraxfs_uart_exit);

drivers/tty/serial/fsl_lpuart.c

···
 	unsigned int		rxfifo_size;
 	bool			lpuart32;
 
-	bool			lpuart_dma_use;
+	bool			lpuart_dma_tx_use;
+	bool			lpuart_dma_rx_use;
 	struct dma_chan		*dma_tx_chan;
 	struct dma_chan		*dma_rx_chan;
 	struct dma_async_tx_descriptor  *dma_tx_desc;
···
 	return 0;
 }
 
+static void lpuart_flush_buffer(struct uart_port *port)
+{
+	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
+	if (sport->lpuart_dma_tx_use) {
+		dmaengine_terminate_all(sport->dma_tx_chan);
+		sport->dma_tx_in_progress = 0;
+	}
+}
+
 static void lpuart_dma_rx_complete(void *arg)
 {
 	struct lpuart_port *sport = arg;
···
 	unsigned long flags;
 
 	async_tx_ack(sport->dma_rx_desc);
+	mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 
···
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 
-	init_timer(&sport->lpuart_timer);
-	sport->lpuart_timer.function = lpuart_timer_func;
-	sport->lpuart_timer.data = (unsigned long)sport;
 	sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
 	add_timer(&sport->lpuart_timer);
 
···
 	temp = readb(port->membase + UARTCR2);
 	writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
 
-	if (sport->lpuart_dma_use) {
+	if (sport->lpuart_dma_tx_use) {
 		if (!uart_circ_empty(xmit) && !sport->dma_tx_in_progress)
 			lpuart_prepare_tx(sport);
 	} else {
···
 static irqreturn_t lpuart_int(int irq, void *dev_id)
 {
 	struct lpuart_port *sport = dev_id;
-	unsigned char sts;
+	unsigned char sts, crdma;
 
 	sts = readb(sport->port.membase + UARTSR1);
+	crdma = readb(sport->port.membase + UARTCR5);
 
-	if (sts & UARTSR1_RDRF) {
-		if (sport->lpuart_dma_use)
+	if (sts & UARTSR1_RDRF && !(crdma & UARTCR5_RDMAS)) {
+		if (sport->lpuart_dma_rx_use)
 			lpuart_prepare_rx(sport);
 		else
 			lpuart_rxint(irq, dev_id);
 	}
-	if (sts & UARTSR1_TDRE &&
-		!(readb(sport->port.membase + UARTCR5) & UARTCR5_TDMAS)) {
-		if (sport->lpuart_dma_use)
+	if (sts & UARTSR1_TDRE && !(crdma & UARTCR5_TDMAS)) {
+		if (sport->lpuart_dma_tx_use)
 			lpuart_pio_tx(sport);
 		else
 			lpuart_txint(irq, dev_id);
···
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *tx_chan;
 	struct dma_slave_config dma_tx_sconfig;
 	dma_addr_t dma_bus;
 	unsigned char *dma_buf;
 	int ret;
 
-	tx_chan  = dma_request_slave_channel(sport->port.dev, "tx");
-
-	if (!tx_chan) {
-		dev_err(sport->port.dev, "Dma tx channel request failed!\n");
-		return -ENODEV;
-	}
-
-	dma_bus = dma_map_single(tx_chan->device->dev,
+	dma_bus = dma_map_single(sport->dma_tx_chan->device->dev,
 				sport->port.state->xmit.buf,
 				UART_XMIT_SIZE, DMA_TO_DEVICE);
 
-	if (dma_mapping_error(tx_chan->device->dev, dma_bus)) {
+	if (dma_mapping_error(sport->dma_tx_chan->device->dev, dma_bus)) {
 		dev_err(sport->port.dev, "dma_map_single tx failed\n");
-		dma_release_channel(tx_chan);
 		return -ENOMEM;
 	}
 
···
 	dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	dma_tx_sconfig.dst_maxburst = sport->txfifo_size;
 	dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
-	ret = dmaengine_slave_config(tx_chan, &dma_tx_sconfig);
+	ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
 
 	if (ret < 0) {
 		dev_err(sport->port.dev,
 				"Dma slave config failed, err = %d\n", ret);
-		dma_release_channel(tx_chan);
 		return ret;
 	}
 
-	sport->dma_tx_chan = tx_chan;
 	sport->dma_tx_buf_virt = dma_buf;
 	sport->dma_tx_buf_bus = dma_bus;
 	sport->dma_tx_in_progress = 0;
···
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *rx_chan;
 	struct dma_slave_config dma_rx_sconfig;
 	dma_addr_t dma_bus;
 	unsigned char *dma_buf;
 	int ret;
-
-	rx_chan  = dma_request_slave_channel(sport->port.dev, "rx");
-
-	if (!rx_chan) {
-		dev_err(sport->port.dev, "Dma rx channel request failed!\n");
-		return -ENODEV;
-	}
 
 	dma_buf = devm_kzalloc(sport->port.dev,
 				FSL_UART_RX_DMA_BUFFER_SIZE, GFP_KERNEL);
 
 	if (!dma_buf) {
 		dev_err(sport->port.dev, "Dma rx alloc failed\n");
-		dma_release_channel(rx_chan);
 		return -ENOMEM;
 	}
 
-	dma_bus = dma_map_single(rx_chan->device->dev, dma_buf,
+	dma_bus = dma_map_single(sport->dma_rx_chan->device->dev, dma_buf,
 				FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
 
-	if (dma_mapping_error(rx_chan->device->dev, dma_bus)) {
+	if (dma_mapping_error(sport->dma_rx_chan->device->dev, dma_bus)) {
 		dev_err(sport->port.dev, "dma_map_single rx failed\n");
-		dma_release_channel(rx_chan);
 		return -ENOMEM;
 	}
 
···
 	dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	dma_rx_sconfig.src_maxburst = 1;
 	dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
-	ret = dmaengine_slave_config(rx_chan, &dma_rx_sconfig);
+	ret = dmaengine_slave_config(sport->dma_rx_chan, &dma_rx_sconfig);
 
 	if (ret < 0) {
 		dev_err(sport->port.dev,
 				"Dma slave config failed, err = %d\n", ret);
-		dma_release_channel(rx_chan);
 		return ret;
 	}
 
-	sport->dma_rx_chan = rx_chan;
 	sport->dma_rx_buf_virt = dma_buf;
 	sport->dma_rx_buf_bus = dma_bus;
 	sport->dma_rx_in_progress = 0;
···
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *dma_chan;
 
 	dma_unmap_single(sport->port.dev, sport->dma_tx_buf_bus,
 			UART_XMIT_SIZE, DMA_TO_DEVICE);
-	dma_chan = sport->dma_tx_chan;
-	sport->dma_tx_chan = NULL;
+
 	sport->dma_tx_buf_bus = 0;
 	sport->dma_tx_buf_virt = NULL;
-	dma_release_channel(dma_chan);
 }
 
 static void lpuart_dma_rx_free(struct uart_port *port)
 {
 	struct lpuart_port *sport = container_of(port,
 					struct lpuart_port, port);
-	struct dma_chan *dma_chan;
 
 	dma_unmap_single(sport->port.dev, sport->dma_rx_buf_bus,
 			FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
 
-	dma_chan = sport->dma_rx_chan;
-	sport->dma_rx_chan = NULL;
 	sport->dma_rx_buf_bus = 0;
 	sport->dma_rx_buf_virt = NULL;
-	dma_release_channel(dma_chan);
 }
 
 static int lpuart_startup(struct uart_port *port)
···
 	sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) &
 		UARTPFIFO_FIFOSIZE_MASK) + 1);
 
-	/* Whether use dma support by dma request results */
-	if (lpuart_dma_tx_request(port) || lpuart_dma_rx_request(port)) {
-		sport->lpuart_dma_use = false;
-	} else {
-		sport->lpuart_dma_use = true;
+	if (sport->dma_rx_chan && !lpuart_dma_rx_request(port)) {
+		sport->lpuart_dma_rx_use = true;
+		setup_timer(&sport->lpuart_timer, lpuart_timer_func,
+			    (unsigned long)sport);
+	} else
+		sport->lpuart_dma_rx_use = false;
+
+
+	if (sport->dma_tx_chan && !lpuart_dma_tx_request(port)) {
+		sport->lpuart_dma_tx_use = true;
 		temp = readb(port->membase + UARTCR5);
+		temp &= ~UARTCR5_RDMAS;
 		writeb(temp | UARTCR5_TDMAS, port->membase + UARTCR5);
-	}
+	} else
+		sport->lpuart_dma_tx_use = false;
 
 	ret = devm_request_irq(port->dev, port->irq, lpuart_int, 0,
 				DRIVER_NAME, sport);
···
 
 	devm_free_irq(port->dev, port->irq, sport);
 
-	if (sport->lpuart_dma_use) {
-		lpuart_dma_tx_free(port);
-		lpuart_dma_rx_free(port);
+	if (sport->lpuart_dma_rx_use) {
+		lpuart_dma_rx_free(&sport->port);
+		del_timer_sync(&sport->lpuart_timer);
 	}
+
+	if (sport->lpuart_dma_tx_use)
+		lpuart_dma_tx_free(&sport->port);
 }
 
 static void lpuart32_shutdown(struct uart_port *port)
···
 	/* update the per-port timeout */
 	uart_update_timeout(port, termios->c_cflag, baud);
 
-	if (sport->lpuart_dma_use) {
+	if (sport->lpuart_dma_rx_use) {
 		/* Calculate delay for 1.5 DMA buffers */
 		sport->dma_rx_timeout = (sport->port.timeout - HZ / 50) *
 					FSL_UART_RX_DMA_BUFFER_SIZE * 3 /
···
 	.release_port	= lpuart_release_port,
 	.config_port	= lpuart_config_port,
 	.verify_port	= lpuart_verify_port,
+	.flush_buffer	= lpuart_flush_buffer,
 };
 
 static struct uart_ops lpuart32_pops = {
···
 	.release_port	= lpuart_release_port,
 	.config_port	= lpuart_config_port,
 	.verify_port	= lpuart_verify_port,
+	.flush_buffer	= lpuart_flush_buffer,
 };
 
 static struct lpuart_port *lpuart_ports[UART_NR];
···
 		return ret;
 	}
 
+	sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
+	if (!sport->dma_tx_chan)
+		dev_info(sport->port.dev, "DMA tx channel request failed, "
+				"operating without tx DMA\n");
+
+	sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx");
+	if (!sport->dma_rx_chan)
+		dev_info(sport->port.dev, "DMA rx channel request failed, "
+				"operating without rx DMA\n");
+
 	return 0;
 }
 
···
 
 	clk_disable_unprepare(sport->clk);
 
+	if (sport->dma_tx_chan)
+		dma_release_channel(sport->dma_tx_chan);
+
+	if (sport->dma_rx_chan)
+		dma_release_channel(sport->dma_rx_chan);
+
 	return 0;
 }
 
···
 static int lpuart_suspend(struct device *dev)
 {
 	struct lpuart_port *sport = dev_get_drvdata(dev);
+	unsigned long temp;
+
+	if (sport->lpuart32) {
+		/* disable Rx/Tx and interrupts */
+		temp = lpuart32_read(sport->port.membase + UARTCTRL);
+		temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
+		lpuart32_write(temp, sport->port.membase + UARTCTRL);
+	} else {
+		/* disable Rx/Tx and interrupts */
+		temp = readb(sport->port.membase + UARTCR2);
+		temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
+		writeb(temp, sport->port.membase + UARTCR2);
+	}
 
 	uart_suspend_port(&lpuart_reg, &sport->port);
 

drivers/tty/serial/imx.c

···
 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
 
 /* UART Control Register Bit Fields.*/
+#define URXD_DUMMY_READ (1<<16)
 #define URXD_CHARRDY	(1<<15)
 #define URXD_ERR	(1<<14)
 #define URXD_OVRRUN	(1<<13)
···
 	mod_timer(&sport->timer, jiffies);
 }
 
+static void imx_dma_tx(struct imx_port *sport);
 static inline void imx_transmit_buffer(struct imx_port *sport)
 {
 	struct circ_buf *xmit = &sport->port.state->xmit;
+	unsigned long temp;
 
 	if (sport->port.x_char) {
 		/* Send next char */
 		writel(sport->port.x_char, sport->port.membase + URTX0);
+		sport->port.icount.tx++;
+		sport->port.x_char = 0;
 		return;
 	}
 
 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
 		imx_stop_tx(&sport->port);
 		return;
+	}
+
+	if (sport->dma_is_enabled) {
+		/*
+		 * We've just sent a X-char Ensure the TX DMA is enabled
+		 * and the TX IRQ is disabled.
+		 **/
+		temp = readl(sport->port.membase + UCR1);
+		temp &= ~UCR1_TXMPTYEN;
+		if (sport->dma_is_txing) {
+			temp |= UCR1_TDMAEN;
+			writel(temp, sport->port.membase + UCR1);
+		} else {
+			writel(temp, sport->port.membase + UCR1);
+			imx_dma_tx(sport);
+		}
 	}
 
 	while (!uart_circ_empty(xmit) &&
···
 	struct scatterlist *sgl = &sport->tx_sgl[0];
 	struct circ_buf *xmit = &sport->port.state->xmit;
 	unsigned long flags;
+	unsigned long temp;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
 
 	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 
-	sport->dma_is_txing = 0;
+	temp = readl(sport->port.membase + UCR1);
+	temp &= ~UCR1_TDMAEN;
+	writel(temp, sport->port.membase + UCR1);
 
 	/* update the stat */
-	spin_lock_irqsave(&sport->port.lock, flags);
 	xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
 	sport->port.icount.tx += sport->tx_bytes;
-	spin_unlock_irqrestore(&sport->port.lock, flags);
 
 	dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
 
-	uart_write_wakeup(&sport->port);
+	sport->dma_is_txing = 0;
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
 
 	if (waitqueue_active(&sport->dma_wait)) {
 		wake_up(&sport->dma_wait);
 		dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
 		return;
 	}
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
+		imx_dma_tx(sport);
+	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 
 static void imx_dma_tx(struct imx_port *sport)
···
 	struct dma_async_tx_descriptor *desc;
 	struct dma_chan	*chan = sport->dma_chan_tx;
 	struct device *dev = sport->port.dev;
-	enum dma_status status;
+	unsigned long temp;
 	int ret;
 
-	status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
-	if (DMA_IN_PROGRESS == status)
+	if (sport->dma_is_txing)
 		return;
 
 	sport->tx_bytes = uart_circ_chars_pending(xmit);
 
-	if (xmit->tail > xmit->head && xmit->head > 0) {
+	if (xmit->tail < xmit->head) {
+		sport->dma_tx_nents = 1;
+		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
+	} else {
 		sport->dma_tx_nents = 2;
 		sg_init_table(sgl, 2);
 		sg_set_buf(sgl, xmit->buf + xmit->tail,
 				UART_XMIT_SIZE - xmit->tail);
 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
-	} else {
-		sport->dma_tx_nents = 1;
-		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
 	}
 
 	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
···
 	desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
 					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 	if (!desc) {
+		dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
+			     DMA_TO_DEVICE);
 		dev_err(dev, "We cannot prepare for the TX slave dma!\n");
 		return;
 	}
···
 
 	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
 			uart_circ_chars_pending(xmit));
+
+	temp = readl(sport->port.membase + UCR1);
+	temp |= UCR1_TDMAEN;
+	writel(temp, sport->port.membase + UCR1);
+
 	/* fire it */
 	sport->dma_is_txing = 1;
 	dmaengine_submit(desc);
···
 		temp &= ~(UCR1_RRDYEN);
 		writel(temp, sport->port.membase + UCR1);
 	}
-	/* Clear any pending ORE flag before enabling interrupt */
-	temp = readl(sport->port.membase + USR2);
-	writel(temp | USR2_ORE, sport->port.membase + USR2);
-
-	temp = readl(sport->port.membase + UCR4);
-	temp |= UCR4_OREN;
-	writel(temp, sport->port.membase + UCR4);
 
 	if (!sport->dma_is_enabled) {
 		temp = readl(sport->port.membase + UCR1);
···
 	}
 
 	if (sport->dma_is_enabled) {
-		/* FIXME: port->x_char must be transmitted if != 0 */
+		if (sport->port.x_char) {
+			/* We have X-char to send, so enable TX IRQ and
+			 * disable TX DMA to let TX interrupt to send X-char */
+			temp = readl(sport->port.membase + UCR1);
+			temp &= ~UCR1_TDMAEN;
+			temp |= UCR1_TXMPTYEN;
+			writel(temp, sport->port.membase + UCR1);
+			return;
+		}
+
 		if (!uart_circ_empty(&port->state->xmit) &&
 		    !uart_tx_stopped(port))
 			imx_dma_tx(sport);
 		return;
 	}
-
-	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
-		imx_transmit_buffer(sport);
 }
 
 static irqreturn_t imx_rtsint(int irq, void *dev_id)
···
 				continue;
 			}
 
-			rx &= sport->port.read_status_mask;
+			rx &= (sport->port.read_status_mask | 0xFF);
 
 			if (rx & URXD_BRK)
 				flg = TTY_BREAK;
···
 			sport->port.sysrq = 0;
 #endif
 		}
+
+		if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
+			goto out;
 
 		tty_insert_flip_char(port, rx, flg);
 	}
···
 static void imx_dma_rxint(struct imx_port *sport)
 {
 	unsigned long temp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
 
 	temp = readl(sport->port.membase + USR2);
 	if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
···
 		/* tell the DMA to receive the data. */
 		start_rx_dma(sport);
 	}
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 
 static irqreturn_t imx_int(int irq, void *dev_id)
···
 static void imx_rx_dma_done(struct imx_port *sport)
 {
 	unsigned long temp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
 
 	/* Enable this interrupt when the RXFIFO is empty. */
 	temp = readl(sport->port.membase + UCR1);
···
 	/* Is the shutdown waiting for us? */
 	if (waitqueue_active(&sport->dma_wait))
 		wake_up(&sport->dma_wait);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 
 /*
···
 	dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
 
 	if (count) {
-		tty_insert_flip_string(port, sport->rx_buf, count);
+		if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ))
+			tty_insert_flip_string(port, sport->rx_buf, count);
 		tty_flip_buffer_push(port);
 
 		start_rx_dma(sport);
-	} else
+	} else if (readl(sport->port.membase + USR2) & USR2_RDR) {
+		/*
+		 * start rx_dma directly once data in RXFIFO, more efficient
+		 * than before:
+		 *	1. call imx_rx_dma_done to stop dma if no data received
+		 *	2. wait next  RDR interrupt to start dma transfer.
+		 */
+		start_rx_dma(sport);
+	} else {
+		/*
+		 * stop dma to prevent too many IDLE event trigged if no data
+		 * in RXFIFO
+		 */
 		imx_rx_dma_done(sport);
+	}
 }
 
 static int start_rx_dma(struct imx_port *sport)
···
 	desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
 					DMA_PREP_INTERRUPT);
 	if (!desc) {
+		dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
 		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
 		return -EINVAL;
 	}
···
 	while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
 		udelay(1);
 
+	/* Can we enable the DMA support? */
+	if (is_imx6q_uart(sport) && !uart_console(port) &&
+	    !sport->dma_is_inited)
+		imx_uart_dma_init(sport);
+
 	spin_lock_irqsave(&sport->port.lock, flags);
 	/*
 	 * Finally, clear and enable interrupts
 	 */
 	writel(USR1_RTSD, sport->port.membase + USR1);
+
+	if (sport->dma_is_inited && !sport->dma_is_enabled)
+		imx_enable_dma(sport);
 
 	temp = readl(sport->port.membase + UCR1);
 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
···
 	}
 
 	writel(temp, sport->port.membase + UCR1);
+
+	/* Clear any pending ORE flag before enabling interrupt */
+	temp = readl(sport->port.membase + USR2);
+	writel(temp | USR2_ORE, sport->port.membase + USR2);
+
+	temp = readl(sport->port.membase + UCR4);
+	temp |= UCR4_OREN;
+	writel(temp, sport->port.membase + UCR4);
 
 	temp = readl(sport->port.membase + UCR2);
 	temp |= (UCR2_RXEN | UCR2_TXEN);
···
 			dmaengine_terminate_all(sport->dma_chan_tx);
 			dmaengine_terminate_all(sport->dma_chan_rx);
 		}
+		spin_lock_irqsave(&sport->port.lock, flags);
 		imx_stop_tx(port);
 		imx_stop_rx(port);
 		imx_disable_dma(sport);
+		spin_unlock_irqrestore(&sport->port.lock, flags);
 		imx_uart_dma_exit(sport);
 	}
 
···
 static void imx_flush_buffer(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
+	struct scatterlist *sgl = &sport->tx_sgl[0];
+	unsigned long temp;
+	int i = 100, ubir, ubmr, ubrc, uts;
 
-	if (sport->dma_is_enabled) {
-		sport->tx_bytes = 0;
-		dmaengine_terminate_all(sport->dma_chan_tx);
+	if (!sport->dma_chan_tx)
+		return;
+
+	sport->tx_bytes = 0;
+	dmaengine_terminate_all(sport->dma_chan_tx);
+	if (sport->dma_is_txing) {
+		dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
+			     DMA_TO_DEVICE);
+		temp = readl(sport->port.membase + UCR1);
+		temp &= ~UCR1_TDMAEN;
+		writel(temp, sport->port.membase + UCR1);
+		sport->dma_is_txing = false;
 	}
+
+	/*
+	 * According to the Reference Manual description of the UART SRST bit:
+	 * "Reset the transmit and receive state machines,
+	 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
+	 * and UTS[6-3]". As we don't need to restore the old values from
+	 * USR1, USR2, URXD, UTXD, only save/restore the other four registers
+	 */
+	ubir = readl(sport->port.membase + UBIR);
+	ubmr = readl(sport->port.membase + UBMR);
+	ubrc = readl(sport->port.membase + UBRC);
+	uts = readl(sport->port.membase + IMX21_UTS);
+
+	temp = readl(sport->port.membase + UCR2);
+	temp &= ~UCR2_SRST;
+	writel(temp, sport->port.membase + UCR2);
+
+	while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
+		udelay(1);
+
+	/* Restore the registers */
+	writel(ubir, sport->port.membase + UBIR);
+	writel(ubmr, sport->port.membase + UBMR);
+	writel(ubrc, sport->port.membase + UBRC);
+	writel(uts, sport->port.membase + IMX21_UTS);
 }
 
 static void
···
 		if (sport->have_rtscts) {
 			ucr2 &= ~UCR2_IRTS;
 			ucr2 |= UCR2_CTSC;
-
-			/* Can we enable the DMA support? */
-			if (is_imx6q_uart(sport) && !uart_console(port)
-				&& !sport->dma_is_inited)
-				imx_uart_dma_init(sport);
 		} else {
 			termios->c_cflag &= ~CRTSCTS;
 		}
···
 	 */
 	sport->port.ignore_status_mask = 0;
 	if (termios->c_iflag & IGNPAR)
-		sport->port.ignore_status_mask |= URXD_PRERR;
+		sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
 	if (termios->c_iflag & IGNBRK) {
 		sport->port.ignore_status_mask |= URXD_BRK;
 		/*
···
 		if (termios->c_iflag & IGNPAR)
 			sport->port.ignore_status_mask |= URXD_OVRRUN;
 	}
+
+	if ((termios->c_cflag & CREAD) == 0)
+		sport->port.ignore_status_mask |= URXD_DUMMY_READ;
 
 	/*
 	 * Update the per-port timeout.
···
 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
 		imx_enable_ms(&sport->port);
 
-	if (sport->dma_is_inited && !sport->dma_is_enabled)
-		imx_enable_dma(sport);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 }
 

drivers/tty/serial/mcf.c

···
 /*
  *	mcf.c -- Freescale ColdFire UART driver
  *
- *	(C) Copyright 2003-2007, Greg Ungerer <[e-mail]>
+ *	(C) Copyright 2003-2007, Greg Ungerer <[e-mail]>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
···
 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
 	struct ktermios *old)
 {
-	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 	unsigned long flags;
 	unsigned int baud, baudclk;
 #if defined(CONFIG_M5272)
···
 /* Enable or disable the RS485 support */
 static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
 {
-	struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 	unsigned char mr1, mr2;
 
 	/* Get mode registers */
···
 		port->mapbase = platp[i].mapbase;
 		port->membase = (platp[i].membase) ? platp[i].membase :
 			(unsigned char __iomem *) platp[i].mapbase;
+		port->dev = &pdev->dev;
 		port->iotype = SERIAL_IO_MEM;
 		port->irq = platp[i].irq;
 		port->uartclk = MCF_BUSCLK;
···
 module_init(mcf_init);
 module_exit(mcf_exit);
 
-MODULE_AUTHOR("Greg Ungerer <[e-mail]>");
+MODULE_AUTHOR("Greg Ungerer <[e-mail]>");
 MODULE_DESCRIPTION("Freescale ColdFire UART driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:mcfuart");

drivers/tty/serial/men_z135_uart.c

···
 #define MEN_Z135_MAX_PORTS		12
 #define MEN_Z135_BASECLK		29491200
 #define MEN_Z135_FIFO_SIZE		1024
-#define MEN_Z135_NUM_MSI_VECTORS	2
 #define MEN_Z135_FIFO_WATERMARK		1020
 
 #define MEN_Z135_STAT_REG		0x0
···
 #define MEN_Z135_CONF_REG		0x808
 #define MEN_Z135_UART_FREQ		0x80c
 #define MEN_Z135_BAUD_REG		0x810
-#define MENZ135_TIMEOUT			0x814
+#define MEN_Z135_TIMEOUT		0x814
 
 #define MEN_Z135_MEM_SIZE		0x818
 
-#define IS_IRQ(x) ((x) & 1)
-#define IRQ_ID(x) (((x) >> 1) & 7)
+#define IRQ_ID(x) ((x) & 0x1f)
 
 #define MEN_Z135_IER_RXCIEN BIT(0)		/* RX Space IRQ */
 #define MEN_Z135_IER_TXCIEN BIT(1)		/* TX Space IRQ */
···
 #define MEN_Z135_LSR_TEXP BIT(6)
 #define MEN_Z135_LSR_RXFIFOERR BIT(7)
 
-#define MEN_Z135_IRQ_ID_MST 0
-#define MEN_Z135_IRQ_ID_TSA 1
-#define MEN_Z135_IRQ_ID_RDA 2
-#define MEN_Z135_IRQ_ID_RLS 3
-#define MEN_Z135_IRQ_ID_CTI 6
+#define MEN_Z135_IRQ_ID_RLS BIT(0)
+#define MEN_Z135_IRQ_ID_RDA BIT(1)
+#define MEN_Z135_IRQ_ID_CTI BIT(2)
+#define MEN_Z135_IRQ_ID_TSA BIT(3)
+#define MEN_Z135_IRQ_ID_MST BIT(4)
 
 #define LCR(x) (((x) >> MEN_Z135_LCR_SHIFT) & 0xff)
 
···
 module_param(align, int, S_IRUGO);
 MODULE_PARM_DESC(align, "Keep hardware FIFO write pointer aligned, default 0");
 
+static uint rx_timeout;
+module_param(rx_timeout, uint, S_IRUGO);
+MODULE_PARM_DESC(rx_timeout, "RX timeout. "
+		"Timeout in seconds = (timeout_reg * baud_reg * 4) / freq_reg");
+
 struct men_z135_port {
 	struct uart_port port;
 	struct mcb_device *mdev;
 	unsigned char *rxbuf;
 	u32 stat_reg;
 	spinlock_t lock;
+	bool automode;
 };
 #define to_men_z135(port) container_of((port), struct men_z135_port, port)
 
···
  */
 static void men_z135_handle_modem_status(struct men_z135_port *uart)
 {
-	if (uart->stat_reg & MEN_Z135_MSR_DDCD)
+	u8 msr;
+
+	msr = (uart->stat_reg >> 8) & 0xff;
+
+	if (msr & MEN_Z135_MSR_DDCD)
 		uart_handle_dcd_change(&uart->port,
-				uart->stat_reg & ~MEN_Z135_MSR_DCD);
-	if (uart->stat_reg & MEN_Z135_MSR_DCTS)
+				msr & MEN_Z135_MSR_DCD);
+	if (msr & MEN_Z135_MSR_DCTS)
 		uart_handle_cts_change(&uart->port,
-				uart->stat_reg & ~MEN_Z135_MSR_CTS);
+				msr & MEN_Z135_MSR_CTS);
 }
 
 static void men_z135_handle_lsr(struct men_z135_port *uart)
···
 
 	txfree = MEN_Z135_FIFO_WATERMARK - txc;
 	if (txfree <= 0) {
-		pr_err("Not enough room in TX FIFO have %d, need %d\n",
+		dev_err(&uart->mdev->dev,
+			"Not enough room in TX FIFO have %d, need %d\n",
 			txfree, qlen);
 		goto irq_en;
 	}
···
  * @irq: The IRQ number
  * @data: Pointer to UART port
  *
- * Check IIR register to see which tasklet to start.
+ * Check IIR register to find the cause of the interrupt and handle it.
+ * It is possible that multiple interrupts reason bits are set and reading
+ * the IIR is a destructive read, so we always need to check for all possible
+ * interrupts and handle them.
  */
 static irqreturn_t men_z135_intr(int irq, void *data)
 {
 	struct men_z135_port *uart = (struct men_z135_port *)data;
 	struct uart_port *port = &uart->port;
+	bool handled = false;
+	unsigned long flags;
 	int irq_id;
 
 	uart->stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
-	/* IRQ pending is low active */
-	if (IS_IRQ(uart->stat_reg))
-		return IRQ_NONE;
-
 	irq_id = IRQ_ID(uart->stat_reg);
-	switch (irq_id) {
-	case MEN_Z135_IRQ_ID_MST:
-		men_z135_handle_modem_status(uart);
-		break;
-	case MEN_Z135_IRQ_ID_TSA:
-		men_z135_handle_tx(uart);
-		break;
-	case MEN_Z135_IRQ_ID_CTI:
-		dev_dbg(&uart->mdev->dev, "Character Timeout Indication\n");
-		/* Fallthrough */
-	case MEN_Z135_IRQ_ID_RDA:
-		/* Reading data clears RX IRQ */
-		men_z135_handle_rx(uart);
-		break;
-	case MEN_Z135_IRQ_ID_RLS:
+
+	if (!irq_id)
+		goto out;
+
+	spin_lock_irqsave(&port->lock, flags);
+	/* It's save to write to IIR[7:6] RXC[9:8] */
+	iowrite8(irq_id, port->membase + MEN_Z135_STAT_REG);
+
+	if (irq_id & MEN_Z135_IRQ_ID_RLS) {
 		men_z135_handle_lsr(uart);
-		break;
-	default:
-		dev_warn(&uart->mdev->dev, "Unknown IRQ id %d\n", irq_id);
-		return IRQ_NONE;
+		handled = true;
 	}
 
-	return IRQ_HANDLED;
+	if (irq_id & (MEN_Z135_IRQ_ID_RDA | MEN_Z135_IRQ_ID_CTI)) {
+		if (irq_id & MEN_Z135_IRQ_ID_CTI)
+			dev_dbg(&uart->mdev->dev, "Character Timeout Indication\n");
+		men_z135_handle_rx(uart);
+		handled = true;
+	}
+
+	if (irq_id & MEN_Z135_IRQ_ID_TSA) {
+		men_z135_handle_tx(uart);
+		handled = true;
+	}
+
+	if (irq_id & MEN_Z135_IRQ_ID_MST) {
+		men_z135_handle_modem_status(uart);
+		handled = true;
+	}
+
+	spin_unlock_irqrestore(&port->lock, flags);
+out:
+	return IRQ_RETVAL(handled);
 }
 
 /**
···
  */
 static void men_z135_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-	struct men_z135_port *uart = to_men_z135(port);
-	u32 conf_reg = 0;
+	u32 old;
+	u32 conf_reg;
 
+	conf_reg = old = ioread32(port->membase + MEN_Z135_CONF_REG);
 	if (mctrl & TIOCM_RTS)
 		conf_reg |= MEN_Z135_MCR_RTS;
+	else
+		conf_reg &= ~MEN_Z135_MCR_RTS;
+
 	if (mctrl & TIOCM_DTR)
 		conf_reg |= MEN_Z135_MCR_DTR;
+	else
+		conf_reg &= ~MEN_Z135_MCR_DTR;
+
 	if (mctrl & TIOCM_OUT1)
 		conf_reg |= MEN_Z135_MCR_OUT1;
+	else
+		conf_reg &= ~MEN_Z135_MCR_OUT1;
+
 	if (mctrl & TIOCM_OUT2)
 		conf_reg |= MEN_Z135_MCR_OUT2;
+	else
+		conf_reg &= ~MEN_Z135_MCR_OUT2;
+
 	if (mctrl & TIOCM_LOOP)
 		conf_reg |= MEN_Z135_MCR_LOOP;
+	else
+		conf_reg &= ~MEN_Z135_MCR_LOOP;
 
-	men_z135_reg_set(uart, MEN_Z135_CONF_REG, conf_reg);
+	if (conf_reg != old)
+		iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
 }
 
 /**
···
 static unsigned int men_z135_get_mctrl(struct uart_port *port)
 {
 	unsigned int mctrl = 0;
-	u32 stat_reg;
 	u8 msr;
 
-	stat_reg = ioread32(port->membase + MEN_Z135_STAT_REG);
-
-	msr = ~((stat_reg >> 8) & 0xff);
+	msr = ioread8(port->membase + MEN_Z135_STAT_REG + 1);
 
 	if (msr & MEN_Z135_MSR_CTS)
 		mctrl |= TIOCM_CTS;
···
 	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN);
 }
 
+/*
+ * men_z135_disable_ms() - Disable Modem Status
+ * port: The UART port
+ *
+ * Enable Modem Status IRQ.
+ */
+static void men_z135_disable_ms(struct uart_port *port)
+{
+	struct men_z135_port *uart = to_men_z135(port);
+
+	men_z135_reg_clr(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_MSIEN);
+}
+
 /**
  * men_z135_start_tx() - Start transmitting characters
  * @port: The UART port
···
 static void men_z135_start_tx(struct uart_port *port)
 {
 	struct men_z135_port *uart = to_men_z135(port);
+
+	if (uart->automode)
+		men_z135_disable_ms(port);
 
 	men_z135_handle_tx(uart);
 }
···
 
 	iowrite32(conf_reg, port->membase + MEN_Z135_CONF_REG);
 
+	if (rx_timeout)
+		iowrite32(rx_timeout, port->membase + MEN_Z135_TIMEOUT);
+
 	return 0;
 }
 
···
 				struct ktermios *termios,
 				struct ktermios *old)
 {
+	struct men_z135_port *uart = to_men_z135(port);
 	unsigned int baud;
 	u32 conf_reg;
 	u32 bd_reg;
···
 			lcr |= MEN_Z135_PTY_EVN << MEN_Z135_PTY_SHIFT;
 	} else
 		lcr |= MEN_Z135_PAR_DIS << MEN_Z135_PEN_SHIFT;
+
+	conf_reg |= MEN_Z135_IER_MSIEN;
+	if (termios->c_cflag & CRTSCTS) {
+		conf_reg |= MEN_Z135_MCR_RCFC;
+		uart->automode = true;
+		termios->c_cflag &= ~CLOCAL;
+	} else {
+		conf_reg &= ~MEN_Z135_MCR_RCFC;
+		uart->automode = false;
+	}
 
 	termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
 

drivers/tty/serial/mrst_max3110.c

···
-/*
- *  mrst_max3110.c - spi uart protocol driver for Maxim 3110
- *
- * Copyright (c) 2008-2010, Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-/*
- * Note:
- * 1. From Max3110 spec, the Rx FIFO has 8 words, while the Tx FIFO only has
- *    1 word. If SPI master controller doesn't support sclk frequency change,
- *    then the char need be sent out one by one with some delay
- *
- * 2. Currently only RX available interrupt is used, no need for waiting TXE
- *    interrupt for a low speed UART device
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#ifdef CONFIG_MAGIC_SYSRQ
-#define SUPPORT_SYSRQ
-#endif
-
-#include <linux/module.h>
-#include <linux/ioport.h>
-#include <linux/irq.h>
-#include <linux/init.h>
-#include <linux/console.h>
-#include <linux/tty.h>
-#include <linux/tty_flip.h>
-#include <linux/serial_core.h>
-#include <linux/serial_reg.h>
-
-#include <linux/kthread.h>
-#include <linux/spi/spi.h>
-#include <linux/pm.h>
-
-#include "mrst_max3110.h"
-
-#define UART_TX_NEEDED 1
-#define CON_TX_NEEDED  2
-#define BIT_IRQ_PENDING    3
-
-struct uart_max3110 {
-	struct uart_port port;
-	struct spi_device *spi;
-	char name[SPI_NAME_SIZE];
-
-	wait_queue_head_t wq;
-	struct task_struct *main_thread;
-	struct task_struct *read_thread;
-	struct mutex thread_mutex;
-	struct mutex io_mutex;
-
-	u32 baud;
-	u16 cur_conf;
-	u8 clock;
-	u8 parity, word_7bits;
-	u16 irq;
-
-	unsigned long uart_flags;
-
-	/* console related */
-	struct circ_buf con_xmit;
-};
-
-/* global data structure, may need be removed */
-static struct uart_max3110 *pmax;
-
-static int receive_chars(struct uart_max3110 *max,
-				unsigned short *str, int len);
-static int max3110_read_multi(struct uart_max3110 *max);
-static void max3110_con_receive(struct uart_max3110 *max);
-
-static int max3110_write_then_read(struct uart_max3110 *max,
-		const void *txbuf, void *rxbuf, unsigned len, int always_fast)
-{
-	struct spi_device *spi = max->spi;
-	struct spi_message	message;
-	struct spi_transfer	x;
-	int ret;
-
-	mutex_lock(&max->io_mutex);
-	spi_message_init(&message);
-	memset(&x, 0, sizeof x);
-	x.len = len;
-	x.tx_buf = txbuf;
-	x.rx_buf = rxbuf;
-	spi_message_add_tail(&x, &message);
-
-	if (always_fast)
-		x.speed_hz = spi->max_speed_hz;
-	else if (max->baud)
-		x.speed_hz = max->baud;
-
-	/* Do the i/o */
-	ret = spi_sync(spi, &message);
-	mutex_unlock(&max->io_mutex);
-	return ret;
-}
-
-/* Write a 16b word to the device */
-static int max3110_out(struct uart_max3110 *max, const u16 out)
-{
-	void *buf;
-	u16 *obuf, *ibuf;
-	int ret;
-
-	buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
-	if (!buf)
-		return -ENOMEM;
-
-	obuf = buf;
-	ibuf = buf + 4;
-	*obuf = out;
-	ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
-	if (ret) {
-		pr_warn("%s: get err msg %d when sending 0x%x\n",
-			__func__, ret, out);
-		goto exit;
-	}
-
-	receive_chars(max, ibuf, 1);
-
-exit:
-	kfree(buf);
-	return ret;
-}
-
-/*
- * This is usually used to read data from SPIC RX FIFO, which doesn't
- * need any delay like flushing character out.
- *
- * Return how many valide bytes are read back
- */
-static int max3110_read_multi(struct uart_max3110 *max)
-{
-	void *buf;
-	u16 *obuf, *ibuf;
-	int ret, blen;
-
-	blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
-	buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
-	if (!buf)
-		return 0;
-
-	/* tx/rx always have the same length */
-	obuf = buf;
-	ibuf = buf + blen;
-
-	if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
-		kfree(buf);
-		return 0;
-	}
-
-	ret = receive_chars(max, ibuf, M3110_RX_FIFO_DEPTH);
-
-	kfree(buf);
-	return ret;
-}
-
-static void serial_m3110_con_putchar(struct uart_port *port, int ch)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	struct circ_buf *xmit = &max->con_xmit;
-
-	if (uart_circ_chars_free(xmit)) {
-		xmit->buf[xmit->head] = (char)ch;
-		xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
-	}
-}
-
-/*
- * Print a string to the serial port trying not to disturb
- * any possible real use of the port...
- *
- *	The console_lock must be held when we get here.
- */
-static void serial_m3110_con_write(struct console *co,
-				const char *s, unsigned int count)
-{
-	if (!pmax)
-		return;
-
-	uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
-
-	if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
-		wake_up(&pmax->wq);
-}
-
-static int __init
-serial_m3110_con_setup(struct console *co, char *options)
-{
-	struct uart_max3110 *max = pmax;
-	int baud = 115200;
-	int bits = 8;
-	int parity = 'n';
-	int flow = 'n';
-
-	pr_info("setting up console\n");
-
-	if (co->index == -1)
-		co->index = 0;
-
-	if (!max) {
-		pr_err("pmax is NULL, return\n");
-		return -ENODEV;
-	}
-
-	if (options)
-		uart_parse_options(options, &baud, &parity, &bits, &flow);
-
-	return uart_set_options(&max->port, co, baud, parity, bits, flow);
-}
-
-static struct tty_driver *serial_m3110_con_device(struct console *co,
-							int *index)
-{
-	struct uart_driver *p = co->data;
-	*index = co->index;
-	return p->tty_driver;
-}
-
-static struct uart_driver serial_m3110_reg;
-static struct console serial_m3110_console = {
-	.name		= "ttyS",
-	.write		= serial_m3110_con_write,
-	.device		= serial_m3110_con_device,
-	.setup		= serial_m3110_con_setup,
-	.flags		= CON_PRINTBUFFER,
-	.index		= -1,
-	.data		= &serial_m3110_reg,
-};
-
-static unsigned int serial_m3110_tx_empty(struct uart_port *port)
-{
-	return 1;
-}
-
-static void serial_m3110_stop_tx(struct uart_port *port)
-{
-	return;
-}
-
-/* stop_rx will be called in spin_lock env */
-static void serial_m3110_stop_rx(struct uart_port *port)
-{
-	return;
-}
-
-#define WORDS_PER_XFER	128
-static void send_circ_buf(struct uart_max3110 *max,
-				struct circ_buf *xmit)
-{
-	void *buf;
-	u16 *obuf, *ibuf;
-	int i, len, blen, dma_size, left, ret = 0;
-
-
-	dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
-	buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
-	if (!buf)
-		return;
-	obuf = buf;
-	ibuf = buf + dma_size/2;
-
-	while (!uart_circ_empty(xmit)) {
-		left = uart_circ_chars_pending(xmit);
-		while (left) {
-			len = min(left, WORDS_PER_XFER);
-			blen = len * sizeof(u16);
-			memset(ibuf, 0, blen);
-
-			for (i = 0; i < len; i++) {
-				obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
-				xmit->tail = (xmit->tail + 1) &
-						(UART_XMIT_SIZE - 1);
-			}
-
-			/* Fail to send msg to console is not very critical */
-
-			ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
-			if (ret)
-				pr_warn("%s: get err msg %d\n", __func__, ret);
-
-			receive_chars(max, ibuf, len);
-
-			max->port.icount.tx += len;
-			left -= len;
-		}
-	}
-
-	kfree(buf);
-}
-
-static void transmit_char(struct uart_max3110 *max)
-{
-	struct uart_port *port = &max->port;
-	struct circ_buf *xmit = &port->state->xmit;
-
-	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
-		return;
-
-	send_circ_buf(max, xmit);
-
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
-		uart_write_wakeup(port);
-
-	if (uart_circ_empty(xmit))
-		serial_m3110_stop_tx(port);
-}
-
-/*
- * This will be called by uart_write() and tty_write, can't
- * go to sleep
- */
-static void serial_m3110_start_tx(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-
-	if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
-		wake_up(&max->wq);
-}
-
-static int
-receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
-{
-	struct uart_port *port = &max->port;
-	struct tty_port *tport;
-	char buf[M3110_RX_FIFO_DEPTH];
-	int r, w, usable;
-
-	/* If uart is not opened, just return */
-	if (!port->state)
-		return 0;
-
-	tport = &port->state->port;
-
-	for (r = 0, w = 0; r < len; r++) {
-		if (str[r] & MAX3110_BREAK &&
-		    uart_handle_break(port))
-			continue;
-
-		if (str[r] & MAX3110_READ_DATA_AVAILABLE) {
-			if (uart_handle_sysrq_char(port, str[r] & 0xff))
-				continue;
-
-			buf[w++] = str[r] & 0xff;
-		}
-	}
-
-	if (!w)
-		return 0;
-
-	for (r = 0; w; r += usable, w -= usable) {
-		usable = tty_buffer_request_room(tport, w);
-		if (usable) {
-			tty_insert_flip_string(tport, buf + r, usable);
-			port->icount.rx += usable;
-		}
-	}
-	tty_flip_buffer_push(tport);
-
-	return r;
-}
-
-/*
- * This routine will be used in read_thread or RX IRQ handling,
- * it will first do one round buffer read(8 words), if there is some
- * valid RX data, will try to read 5 more rounds till all data
- * is read out.
- *
- * Use stack space as data buffer to save some system load, and chose
- * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
- * receiving bulk data, a much bigger buffer may cause stack overflow
- */
-static void max3110_con_receive(struct uart_max3110 *max)
-{
-	int loop = 1, num;
-
-	do {
-		num = max3110_read_multi(max);
-
-		if (num) {
-			loop = 5;
-		}
-	} while (--loop);
-}
-
-static int max3110_main_thread(void *_max)
-{
-	struct uart_max3110 *max = _max;
-	wait_queue_head_t *wq = &max->wq;
-	int ret = 0;
-	struct circ_buf *xmit = &max->con_xmit;
-
-	pr_info("start main thread\n");
-
-	do {
-		wait_event_interruptible(*wq,
-				max->uart_flags || kthread_should_stop());
-
-		mutex_lock(&max->thread_mutex);
-
-		if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
-			max3110_con_receive(max);
-
-		/* first handle console output */
-		if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
-			send_circ_buf(max, xmit);
-
-		/* handle uart output */
-		if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
-			transmit_char(max);
-
-		mutex_unlock(&max->thread_mutex);
-
-	} while (!kthread_should_stop());
-
-	return ret;
-}
-
-static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
-{
-	struct uart_max3110 *max = dev_id;
-
-	/* max3110's irq is a falling edge, not level triggered,
-	 * so no need to disable the irq */
-
-	if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
-		wake_up(&max->wq);
-
-	return IRQ_HANDLED;
-}
-
-/* if don't use RX IRQ, then need a thread to polling read */
-static int max3110_read_thread(void *_max)
-{
-	struct uart_max3110 *max = _max;
-
-	pr_info("start read thread\n");
-	do {
-		/*
-		 * If can't acquire the mutex, it means the main thread
-		 * is running which will also perform the rx job
-		 */
-		if (mutex_trylock(&max->thread_mutex)) {
-			max3110_con_receive(max);
-			mutex_unlock(&max->thread_mutex);
-		}
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(HZ / 20);
-	} while (!kthread_should_stop());
-
-	return 0;
-}
-
-static int serial_m3110_startup(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	u16 config = 0;
-	int ret = 0;
-
-	if (port->line != 0) {
-		pr_err("uart port startup failed\n");
-		return -1;
-	}
-
-	/* Disable all IRQ and config it to 115200, 8n1 */
-	config = WC_TAG | WC_FIFO_ENABLE
-			| WC_1_STOPBITS
-			| WC_8BIT_WORD
-			| WC_BAUD_DR2;
-
-	/* as we use thread to handle tx/rx, need set low latency */
-	port->state->port.low_latency = 1;
-
-	if (max->irq) {
-		/* Enable RX IRQ only */
-		config |= WC_RXA_IRQ_ENABLE;
-	} else {
-		/* If IRQ is disabled, start a read thread for input data */
-		max->read_thread =
-			kthread_run(max3110_read_thread, max, "max3110_read");
-		if (IS_ERR(max->read_thread)) {
-			ret = PTR_ERR(max->read_thread);
-			max->read_thread = NULL;
-			pr_err("Can't create read thread!\n");
-			return ret;
-		}
-	}
-
-	ret = max3110_out(max, config);
-	if (ret) {
-		if (max->read_thread)
-			kthread_stop(max->read_thread);
-		max->read_thread = NULL;
-		return ret;
-	}
-
-	max->cur_conf = config;
-	return 0;
-}
-
-static void serial_m3110_shutdown(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	u16 config;
-
-	if (max->read_thread) {
-		kthread_stop(max->read_thread);
-		max->read_thread = NULL;
-	}
-
-	/* Disable interrupts from this port */
-	config = WC_TAG | WC_SW_SHDI;
-	max3110_out(max, config);
-}
-
-static void serial_m3110_release_port(struct uart_port *port)
-{
-}
-
-static int serial_m3110_request_port(struct uart_port *port)
-{
-	return 0;
-}
-
-static void serial_m3110_config_port(struct uart_port *port, int flags)
-{
-	port->type = PORT_MAX3100;
-}
-
-static int
-serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
-{
-	/* we don't want the core code to modify any port params */
-	return -EINVAL;
-}
-
-
-static const char *serial_m3110_type(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	return max->name;
-}
-
-static void
-serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
-		       struct ktermios *old)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	unsigned char cval;
-	unsigned int baud, parity = 0;
-	int clk_div = -1;
-	u16 new_conf = max->cur_conf;
-
-	switch (termios->c_cflag & CSIZE) {
-	case CS7:
-		cval = UART_LCR_WLEN7;
-		new_conf |= WC_7BIT_WORD;
-		break;
-	default:
-		/* We only support CS7 & CS8 */
-		termios->c_cflag &= ~CSIZE;
-		termios->c_cflag |= CS8;
-	case CS8:
-		cval = UART_LCR_WLEN8;
-		new_conf |= WC_8BIT_WORD;
-		break;
-	}
-
-	baud = uart_get_baud_rate(port, termios, old, 0, 230400);
-
-	/* First calc the div for 1.8MHZ clock case */
-	switch (baud) {
-	case 300:
-		clk_div = WC_BAUD_DR384;
-		break;
-	case 600:
-		clk_div = WC_BAUD_DR192;
-		break;
-	case 1200:
-		clk_div = WC_BAUD_DR96;
-		break;
-	case 2400:
-		clk_div = WC_BAUD_DR48;
-		break;
-	case 4800:
-		clk_div = WC_BAUD_DR24;
-		break;
-	case 9600:
-		clk_div = WC_BAUD_DR12;
-		break;
-	case 19200:
-		clk_div = WC_BAUD_DR6;
-		break;
-	case 38400:
-		clk_div = WC_BAUD_DR3;
-		break;
-	case 57600:
-		clk_div = WC_BAUD_DR2;
-		break;
-	case 115200:
-		clk_div = WC_BAUD_DR1;
-		break;
-	case 230400:
-		if (max->clock & MAX3110_HIGH_CLK)
-			break;
-	default:
-		/* Pick the previous baud rate */
-		baud = max->baud;
-		clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
-		tty_termios_encode_baud_rate(termios, baud, baud);
-	}
-
-	if (max->clock & MAX3110_HIGH_CLK) {
-		clk_div += 1;
-		/* High clk version max3110 doesn't support B300 */
-		if (baud == 300) {
-			baud = 600;
-			clk_div = WC_BAUD_DR384;
-		}
-		if (baud == 230400)
-			clk_div = WC_BAUD_DR1;
-		tty_termios_encode_baud_rate(termios, baud, baud);
-	}
-
-	new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
-
-	if (unlikely(termios->c_cflag & CMSPAR))
-		termios->c_cflag &= ~CMSPAR;
-
-	if (termios->c_cflag & CSTOPB)
-		new_conf |= WC_2_STOPBITS;
-	else
-		new_conf &= ~WC_2_STOPBITS;
-
-	if (termios->c_cflag & PARENB) {
-		new_conf |= WC_PARITY_ENABLE;
-		parity |= UART_LCR_PARITY;
-	} else
-		new_conf &= ~WC_PARITY_ENABLE;
-
-	if (!(termios->c_cflag & PARODD))
-		parity |= UART_LCR_EPAR;
-	max->parity = parity;
-
-	uart_update_timeout(port, termios->c_cflag, baud);
-
-	new_conf |= WC_TAG;
-	if (new_conf != max->cur_conf) {
-		if (!max3110_out(max, new_conf)) {
-			max->cur_conf = new_conf;
-			max->baud = baud;
-		}
-	}
-}
-
-/* Don't handle hw handshaking */
-static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
-{
-	return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
-}
-
-static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
-{
-}
-
-static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
-{
-}
-
-static void serial_m3110_pm(struct uart_port *port, unsigned int state,
-			unsigned int oldstate)
-{
-}
-
-static struct uart_ops serial_m3110_ops = {
-	.tx_empty	= serial_m3110_tx_empty,
-	.set_mctrl	= serial_m3110_set_mctrl,
-	.get_mctrl	= serial_m3110_get_mctrl,
-	.stop_tx	= serial_m3110_stop_tx,
-	.start_tx	= serial_m3110_start_tx,
-	.stop_rx	= serial_m3110_stop_rx,
-	.break_ctl	= serial_m3110_break_ctl,
-	.startup	= serial_m3110_startup,
-	.shutdown	= serial_m3110_shutdown,
-	.set_termios	= serial_m3110_set_termios,
-	.pm		= serial_m3110_pm,
-	.type		= serial_m3110_type,
-	.release_port	= serial_m3110_release_port,
-	.request_port	= serial_m3110_request_port,
-	.config_port	= serial_m3110_config_port,
-	.verify_port	= serial_m3110_verify_port,
-};
-
-static struct uart_driver serial_m3110_reg = {
-	.owner		= THIS_MODULE,
-	.driver_name	= "MRST serial",
-	.dev_name	= "ttyS",
-	.major		= TTY_MAJOR,
-	.minor		= 64,
-	.nr		= 1,
-	.cons		= &serial_m3110_console,
-};
-
-#ifdef CONFIG_PM_SLEEP
-static int serial_m3110_suspend(struct device *dev)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	struct uart_max3110 *max = spi_get_drvdata(spi);
-
-	if (max->irq > 0)
-		disable_irq(max->irq);
-	uart_suspend_port(&serial_m3110_reg, &max->port);
-	max3110_out(max, max->cur_conf | WC_SW_SHDI);
-	return 0;
-}
-
-static int serial_m3110_resume(struct device *dev)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	struct uart_max3110 *max = spi_get_drvdata(spi);
-
-	max3110_out(max, max->cur_conf);
-	uart_resume_port(&serial_m3110_reg, &max->port);
-	if (max->irq > 0)
-		enable_irq(max->irq);
-	return 0;
-}
-
-static SIMPLE_DEV_PM_OPS(serial_m3110_pm_ops, serial_m3110_suspend,
-			serial_m3110_resume);
-#define SERIAL_M3110_PM_OPS (&serial_m3110_pm_ops)
-
-#else
-#define SERIAL_M3110_PM_OPS NULL
-#endif
-
-static int serial_m3110_probe(struct spi_device *spi)
-{
-	struct uart_max3110 *max;
-	void *buffer;
-	u16 res;
-	int ret = 0;
-
-	max = kzalloc(sizeof(*max), GFP_KERNEL);
-	if (!max)
-		return -ENOMEM;
-
-	/* Set spi info */
-	spi->bits_per_word = 16;
-	max->clock = MAX3110_HIGH_CLK;
-
-	spi_setup(spi);
-
-	max->port.type = PORT_MAX3100;
-	max->port.fifosize = 2;		/* Only have 16b buffer */
-	max->port.ops = &serial_m3110_ops;
-	max->port.line = 0;
-	max->port.dev = &spi->dev;
-	max->port.uartclk = 115200;
-
-	max->spi = spi;
-	strcpy(max->name, spi->modalias);
-	max->irq = (u16)spi->irq;
-
-	mutex_init(&max->thread_mutex);
-	mutex_init(&max->io_mutex);
-
-	max->word_7bits = 0;
-	max->parity = 0;
-	max->baud = 0;
-
-	max->cur_conf = 0;
-	max->uart_flags = 0;
-
-	/* Check if reading configuration register returns something sane */
-
-	res = RC_TAG;
-	ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
-	if (ret < 0 || res == 0 || res == 0xffff) {
-		dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
-									res);
-		ret = -ENODEV;
-		goto err_get_page;
-	}
-
-	buffer = (void *)__get_free_page(GFP_KERNEL);
-	if (!buffer) {
-		ret = -ENOMEM;
-		goto err_get_page;
-	}
-	max->con_xmit.buf = buffer;
-	max->con_xmit.head = 0;
-	max->con_xmit.tail = 0;
-
-	init_waitqueue_head(&max->wq);
-
-	max->main_thread = kthread_run(max3110_main_thread,
-					max, "max3110_main");
-	if (IS_ERR(max->main_thread)) {
-		ret = PTR_ERR(max->main_thread);
-		goto err_kthread;
-	}
-
-	if (max->irq) {
-		ret = request_irq(max->irq, serial_m3110_irq,
-				IRQ_TYPE_EDGE_FALLING, "max3110", max);
-		if (ret) {
-			max->irq = 0;
-			dev_warn(&spi->dev,
-			"unable to allocate IRQ, will use polling method\n");
-		}
-	}
-
-	spi_set_drvdata(spi, max);
-	pmax = max;
-
-	/* Give membase a psudo value to pass serial_core's check */
-	max->port.membase = (unsigned char __iomem *)0xff110000;
-	uart_add_one_port(&serial_m3110_reg, &max->port);
-
-	return 0;
-
-err_kthread:
-	free_page((unsigned long)buffer);
-err_get_page:
-	kfree(max);
-	return ret;
-}
-
-static int serial_m3110_remove(struct spi_device *dev)
-{
-	struct uart_max3110 *max = spi_get_drvdata(dev);
-
-	if (!max)
-		return 0;
-
-	uart_remove_one_port(&serial_m3110_reg, &max->port);
-
-	free_page((unsigned long)max->con_xmit.buf);
-
-	if (max->irq)
-		free_irq(max->irq, max);
-
-	if (max->main_thread)
-		kthread_stop(max->main_thread);
-
-	kfree(max);
-	return 0;
-}
-
-static struct spi_driver uart_max3110_driver = {
-	.driver = {
-			.name	= "spi_max3111",
-			.owner	= THIS_MODULE,
-			.pm	= SERIAL_M3110_PM_OPS,
-	},
-	.probe		= serial_m3110_probe,
-	.remove		= serial_m3110_remove,
-};
-
-static int __init serial_m3110_init(void)
-{
-	int ret = 0;
-
-	ret = uart_register_driver(&serial_m3110_reg);
-	if (ret)
-		return ret;
-
-	ret = spi_register_driver(&uart_max3110_driver);
-	if (ret)
-		uart_unregister_driver(&serial_m3110_reg);
-
-	return ret;
-}
-
-static void __exit serial_m3110_exit(void)
-{
-	spi_unregister_driver(&uart_max3110_driver);
-	uart_unregister_driver(&serial_m3110_reg);
-}
-
-module_init(serial_m3110_init);
-module_exit(serial_m3110_exit);
-
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("spi:max3110-uart");

drivers/tty/serial/mrst_max3110.h

···
-#ifndef _MRST_MAX3110_H
-#define _MRST_MAX3110_H
-
-#define MAX3110_HIGH_CLK	0x1	/* 3.6864 MHZ */
-#define MAX3110_LOW_CLK		0x0	/* 1.8432 MHZ */
-
-/* status bits for all 4 MAX3110 operate modes */
-#define MAX3110_READ_DATA_AVAILABLE	(1 << 15)
-#define MAX3110_WRITE_BUF_EMPTY		(1 << 14)
-#define MAX3110_BREAK			(1 << 10)
-
-#define WC_TAG			(3 << 14)
-#define RC_TAG			(1 << 14)
-#define WD_TAG			(2 << 14)
-#define RD_TAG			(0 << 14)
-
-/* bits def for write configuration */
-#define WC_FIFO_ENABLE_MASK	(1 << 13)
-#define WC_FIFO_ENABLE		(0 << 13)
-
-#define WC_SW_SHDI		(1 << 12)
-
-#define WC_IRQ_MASK		(0xF << 8)
-#define WC_TXE_IRQ_ENABLE	(1 << 11)	/* TX empty irq */
-#define WC_RXA_IRQ_ENABLE	(1 << 10)	/* RX available irq */
-#define WC_PAR_HIGH_IRQ_ENABLE	(1 << 9)
-#define WC_REC_ACT_IRQ_ENABLE	(1 << 8)
-
-#define WC_IRDA_ENABLE		(1 << 7)
-
-#define WC_STOPBITS_MASK	(1 << 6)
-#define WC_2_STOPBITS		(1 << 6)
-#define WC_1_STOPBITS		(0 << 6)
-
-#define WC_PARITY_ENABLE_MASK	(1 << 5)
-#define WC_PARITY_ENABLE	(1 << 5)
-
-#define WC_WORDLEN_MASK		(1 << 4)
-#define WC_7BIT_WORD		(1 << 4)
-#define WC_8BIT_WORD		(0 << 4)
-
-#define WC_BAUD_DIV_MASK	(0xF)
-#define WC_BAUD_DR1		(0x0)
-#define WC_BAUD_DR2		(0x1)
-#define WC_BAUD_DR4		(0x2)
-#define WC_BAUD_DR8		(0x3)
-#define WC_BAUD_DR16		(0x4)
-#define WC_BAUD_DR32		(0x5)
-#define WC_BAUD_DR64		(0x6)
-#define WC_BAUD_DR128		(0x7)
-#define WC_BAUD_DR3		(0x8)
-#define WC_BAUD_DR6		(0x9)
-#define WC_BAUD_DR12		(0xA)
-#define WC_BAUD_DR24		(0xB)
-#define WC_BAUD_DR48		(0xC)
-#define WC_BAUD_DR96		(0xD)
-#define WC_BAUD_DR192		(0xE)
-#define WC_BAUD_DR384		(0xF)
-
-#define M3110_RX_FIFO_DEPTH	8
-#endif

drivers/tty/serial/msm_serial.c

···
 static int __init msm_console_setup(struct console *co, char *options)
 {
 	struct uart_port *port;
-	struct msm_port *msm_port;
-	int baud = 0, flow, bits, parity;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
 
 	if (unlikely(co->index >= UART_NR || co->index < 0))
 		return -ENXIO;
 
 	port = get_port_from_line(co->index);
-	msm_port = UART_TO_MSM(port);
 
 	if (unlikely(!port->membase))
 		return -ENXIO;
···
 
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
-
-	bits = 8;
-	parity = 'n';
-	flow = 'n';
-	msm_write(port, UART_MR2_BITS_PER_CHAR_8 | UART_MR2_STOP_BIT_LEN_ONE,
-		  UART_MR2);	/* 8N1 */
-
-	if (baud < 300 || baud > 115200)
-		baud = 115200;
-	msm_set_baud_rate(port, baud);
-
-	msm_reset(port);
-
-	if (msm_port->is_uartdm) {
-		msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR);
-		msm_write(port, UART_CR_TX_ENABLE, UART_CR);
-	}
 
 	pr_info("msm_serial: console setup on port #%d\n", port->line);
 
···
 
 static void __exit msm_serial_exit(void)
 {
-#ifdef CONFIG_SERIAL_MSM_CONSOLE
-	unregister_console(&msm_console);
-#endif
 	platform_driver_unregister(&msm_platform_driver);
 	uart_unregister_driver(&msm_uart_driver);
 }

drivers/tty/serial/mxs-auart.c

···
 	unsigned int mctrl_prev;
 	enum mxs_auart_type devtype;
 
-	unsigned int irq;
-
 	struct clk *clk;
 	struct device *dev;
 
···
 			of_match_device(mxs_auart_dt_ids, &pdev->dev);
 	struct mxs_auart_port *s;
 	u32 version;
-	int ret = 0;
+	int ret, irq;
 	struct resource *r;
 
-	s = kzalloc(sizeof(struct mxs_auart_port), GFP_KERNEL);
-	if (!s) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
 
 	ret = serial_mxs_probe_dt(s, pdev);
 	if (ret > 0)
 		s->port.line = pdev->id < 0 ? 0 : pdev->id;
 	else if (ret < 0)
-		goto out_free;
+		return ret;
 
 	if (of_id) {
 		pdev->id_entry = of_id->data;
 		s->devtype = pdev->id_entry->driver_data;
 	}
 
-	s->clk = clk_get(&pdev->dev, NULL);
-	if (IS_ERR(s->clk)) {
-		ret = PTR_ERR(s->clk);
-		goto out_free;
-	}
+	s->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(s->clk))
+		return PTR_ERR(s->clk);
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!r) {
-		ret = -ENXIO;
-		goto out_free_clk;
-	}
+	if (!r)
+		return -ENXIO;
+
 
 	s->port.mapbase = r->start;
 	s->port.membase = ioremap(r->start, resource_size(r));
···
 
 	s->mctrl_prev = 0;
 
-	s->irq = platform_get_irq(pdev, 0);
-	s->port.irq = s->irq;
-	ret = request_irq(s->irq, mxs_auart_irq_handle, 0, dev_name(&pdev->dev), s);
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	s->port.irq = irq;
+	ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0,
+			       dev_name(&pdev->dev), s);
 	if (ret)
-		goto out_free_clk;
+		return ret;
 
 	platform_set_drvdata(pdev, s);
 
···
 	 */
 	ret = mxs_auart_request_gpio_irq(s);
 	if (ret)
-		goto out_free_irq;
+		return ret;
 
 	auart_port[s->port.line] = s;
 
···
 
 out_free_gpio_irq:
 	mxs_auart_free_gpio_irq(s);
-out_free_irq:
 	auart_port[pdev->id] = NULL;
-	free_irq(s->irq, s);
-out_free_clk:
-	clk_put(s->clk);
-out_free:
-	kfree(s);
-out:
 	return ret;
 }
 
···
 	struct mxs_auart_port *s = platform_get_drvdata(pdev);
 
 	uart_remove_one_port(&auart_driver, &s->port);
-
 	auart_port[pdev->id] = NULL;
-
 	mxs_auart_free_gpio_irq(s);
-	clk_put(s->clk);
-	free_irq(s->irq, s);
-	kfree(s);
 
 	return 0;
 }

drivers/tty/serial/of_serial.c

···
 	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
 		port->fifosize = prop;
 
+	/* Check for a fixed line number */
+	ret = of_alias_get_id(np, "serial");
+	if (ret >= 0)
+		port->line = ret;
+
 	port->irq = irq_of_parse_and_map(np, 0);
 	port->iotype = UPIO_MEM;
 	if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
···
 
 	if (of_find_property(np, "no-loopback-test", NULL))
 		port->flags |= UPF_SKIP_TEST;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret >= 0)
+		port->line = ret;
 
 	port->dev = &ofdev->dev;
 
···
 		.data = (void *)PORT_ALTR_16550_F64, },
 	{ .compatible = "altr,16550-FIFO128",
 		.data = (void *)PORT_ALTR_16550_F128, },
+	{ .compatible = "mrvl,mmp-uart",
+		.data = (void *)PORT_XSCALE, },
+	{ .compatible = "mrvl,pxa-uart",
+		.data = (void *)PORT_XSCALE, },
 #ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
 	{ .compatible = "ibm,qpace-nwp-serial",
 		.data = (void *)PORT_NWPSERIAL, },

drivers/tty/serial/omap-serial.c

···
 #define UART_ERRATA_i202_MDR1_ACCESS	BIT(0)
 #define UART_ERRATA_i291_DMA_FORCEIDLE	BIT(1)
 
-#define DEFAULT_CLK_SPEED 48000000 /* 48Mhz*/
+#define DEFAULT_CLK_SPEED 48000000 /* 48Mhz */
 
 /* SCR register bitmasks */
 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK		(1 << 7)
···
 /* WER = 0x7F
  * Enable module level wakeup in WER reg
  */
-#define OMAP_UART_WER_MOD_WKUP	0X7F
+#define OMAP_UART_WER_MOD_WKUP	0x7F
 
 /* Enable XON/XOFF flow control on output */
 #define OMAP_UART_SW_TX		0x08
···
 	dma_addr_t		tx_buf_dma_phys;
 	unsigned int		uart_base;
 	/*
-	 * Buffer for rx dma.It is not required for tx because the buffer
+	 * Buffer for rx dma. It is not required for tx because the buffer
 	 * comes from port structure.
 	 */
 	unsigned char		*rx_buf;
···
 	int			use_dma;
 	/*
 	 * Some bits in registers are cleared on a read, so they must
-	 * be saved whenever the register is read but the bits will not
+	 * be saved whenever the register is read, but the bits will not
 	 * be immediately processed.
 	 */
 	unsigned int		lsr_break_flag;
···
 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct uart_omap_port *up = to_uart_omap_port(port);
-	unsigned char mcr = 0, old_mcr;
+	unsigned char mcr = 0, old_mcr, lcr;
 
 	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
 	if (mctrl & TIOCM_RTS)
···
 		     UART_MCR_DTR | UART_MCR_RTS);
 	up->mcr = old_mcr | mcr;
 	serial_out(up, UART_MCR, up->mcr);
+
+	/* Turn off autoRTS if RTS is lowered; restore autoRTS if RTS raised */
+	lcr = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+		up->efr |= UART_EFR_RTS;
+	else
+		up->efr &= UART_EFR_RTS;
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, lcr);
+
 	pm_runtime_mark_last_busy(up->dev);
 	pm_runtime_put_autosuspend(up->dev);
 }
···
 	 * (they will be reenabled in set_termios())
 	 */
 	serial_omap_clear_fifos(up);
-	/* For Hardware flow control */
-	serial_out(up, UART_MCR, UART_MCR_RTS);
 
 	/*
 	 * Clear the interrupt registers.
···
 
 	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
 
-	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
-		/* Enable AUTORTS and AUTOCTS */
-		up->efr |= UART_EFR_CTS | UART_EFR_RTS;
+	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
 
-		/* Ensure MCR RTS is asserted */
-		up->mcr |= UART_MCR_RTS;
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
+		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+		up->efr |= UART_EFR_CTS;
 	} else {
 		/* Disable AUTORTS and AUTOCTS */
 		up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
···
 		 * Enable XON/XOFF flow control on output.
 		 * Transmit XON1, XOFF1
 		 */
-		if (termios->c_iflag & IXOFF)
+		if (termios->c_iflag & IXOFF) {
+			up->port.status |= UPSTAT_AUTOXOFF;
 			up->efr |= OMAP_UART_SW_TX;
+		}
 
 		/*
 		 * IXANY Flag:

drivers/tty/serial/samsung.c

···
 #define SUPPORT_SYSRQ
 #endif
 
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
···
 #define S3C24XX_SERIAL_MAJOR	204
 #define S3C24XX_SERIAL_MINOR	64
 
+#define S3C24XX_TX_PIO			1
+#define S3C24XX_TX_DMA			2
+#define S3C24XX_RX_PIO			1
+#define S3C24XX_RX_DMA			2
 /* macros to change one thing to another */
 
 #define tx_enabled(port) ((port)->unused[0])
···
 static void s3c24xx_serial_stop_tx(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct dma_tx_state state;
+	int count;
 
-	if (tx_enabled(port)) {
-		if (s3c24xx_serial_has_interrupt_mask(port))
-			__set_bit(S3C64XX_UINTM_TXD,
-				portaddrl(port, S3C64XX_UINTM));
-		else
-			disable_irq_nosync(ourport->tx_irq);
-		tx_enabled(port) = 0;
-		if (port->flags & UPF_CONS_FLOW)
-			s3c24xx_serial_rx_enable(port);
+	if (!tx_enabled(port))
+		return;
+
+	if (s3c24xx_serial_has_interrupt_mask(port))
+		__set_bit(S3C64XX_UINTM_TXD,
+			portaddrl(port, S3C64XX_UINTM));
+	else
+		disable_irq_nosync(ourport->tx_irq);
+
+	if (dma && dma->tx_chan && ourport->tx_in_progress == S3C24XX_TX_DMA) {
+		dmaengine_pause(dma->tx_chan);
+		dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
+		dmaengine_terminate_all(dma->tx_chan);
+		dma_sync_single_for_cpu(ourport->port.dev,
+			dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE);
+		async_tx_ack(dma->tx_desc);
+		count = dma->tx_bytes_requested - state.residue;
+		xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+		port->icount.tx += count;
 	}
+
+	tx_enabled(port) = 0;
+	ourport->tx_in_progress = 0;
+
+	if (port->flags & UPF_CONS_FLOW)
+		s3c24xx_serial_rx_enable(port);
+
+	ourport->tx_mode = 0;
 }
 
-static void s3c24xx_serial_start_tx(struct uart_port *port)
+static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport);
+
+static void s3c24xx_serial_tx_dma_complete(void *args)
+{
+	struct s3c24xx_uart_port *ourport = args;
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct dma_tx_state state;
+	unsigned long flags;
+	int count;
+
+
+	dmaengine_tx_status(dma->tx_chan, dma->tx_cookie, &state);
+	count = dma->tx_bytes_requested - state.residue;
+	async_tx_ack(dma->tx_desc);
+
+	dma_sync_single_for_cpu(ourport->port.dev, dma->tx_transfer_addr,
+				dma->tx_size, DMA_TO_DEVICE);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+	port->icount.tx += count;
+	ourport->tx_in_progress = 0;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	s3c24xx_serial_start_next_tx(ourport);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void enable_tx_dma(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	u32 ucon;
+
+	/* Mask Tx interrupt */
+	if (s3c24xx_serial_has_interrupt_mask(port))
+		__set_bit(S3C64XX_UINTM_TXD,
+			  portaddrl(port, S3C64XX_UINTM));
+	else
+		disable_irq_nosync(ourport->tx_irq);
+
+	/* Enable tx dma mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
+	ucon |= (dma_get_cache_alignment() >= 16) ?
+		S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
+	ucon |= S3C64XX_UCON_TXMODE_DMA;
+	wr_regl(port,  S3C2410_UCON, ucon);
+
+	ourport->tx_mode = S3C24XX_TX_DMA;
+}
+
+static void enable_tx_pio(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	u32 ucon, ufcon;
+
+	/* Set ufcon txtrig */
+	ourport->tx_in_progress = S3C24XX_TX_PIO;
+	ufcon = rd_regl(port, S3C2410_UFCON);
+	wr_regl(port,  S3C2410_UFCON, ufcon);
+
+	/* Enable tx pio mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_TXMODE_MASK);
+	ucon |= S3C64XX_UCON_TXMODE_CPU;
+	wr_regl(port,  S3C2410_UCON, ucon);
+
+	/* Unmask Tx interrupt */
+	if (s3c24xx_serial_has_interrupt_mask(port))
+		__clear_bit(S3C64XX_UINTM_TXD,
+			    portaddrl(port, S3C64XX_UINTM));
+	else
+		enable_irq(ourport->tx_irq);
+
+	ourport->tx_mode = S3C24XX_TX_PIO;
+}
+
+static void s3c24xx_serial_start_tx_pio(struct s3c24xx_uart_port *ourport)
+{
+	if (ourport->tx_mode != S3C24XX_TX_PIO)
+		enable_tx_pio(ourport);
+}
+
+static int s3c24xx_serial_start_tx_dma(struct s3c24xx_uart_port *ourport,
+				      unsigned int count)
+{
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+
+
+	if (ourport->tx_mode != S3C24XX_TX_DMA)
+		enable_tx_dma(ourport);
+
+	while (xmit->tail & (dma_get_cache_alignment() - 1)) {
+		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
+			return 0;
+		wr_regb(port, S3C2410_UTXH, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		count--;
+	}
+
+	dma->tx_size = count & ~(dma_get_cache_alignment() - 1);
+	dma->tx_transfer_addr = dma->tx_addr + xmit->tail;
+
+	dma_sync_single_for_device(ourport->port.dev, dma->tx_transfer_addr,
+				dma->tx_size, DMA_TO_DEVICE);
+
+	dma->tx_desc = dmaengine_prep_slave_single(dma->tx_chan,
+				dma->tx_transfer_addr, dma->tx_size,
+				DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
+	if (!dma->tx_desc) {
+		dev_err(ourport->port.dev, "Unable to get desc for Tx\n");
+		return -EIO;
+	}
+
+	dma->tx_desc->callback = s3c24xx_serial_tx_dma_complete;
+	dma->tx_desc->callback_param = ourport;
+	dma->tx_bytes_requested = dma->tx_size;
+
+	ourport->tx_in_progress = S3C24XX_TX_DMA;
+	dma->tx_cookie = dmaengine_submit(dma->tx_desc);
+	dma_async_issue_pending(dma->tx_chan);
+	return 0;
+}
+
+static void s3c24xx_serial_start_next_tx(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned long count;
+
+	/* Get data size up to the end of buffer */
+	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	if (!count) {
+		s3c24xx_serial_stop_tx(port);
+		return;
+	}
+
+	if (!ourport->dma || !ourport->dma->tx_chan || count < port->fifosize)
+		s3c24xx_serial_start_tx_pio(ourport);
+	else
+		s3c24xx_serial_start_tx_dma(ourport, count);
+}
+
+void s3c24xx_serial_start_tx(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct circ_buf *xmit = &port->state->xmit;
 
 	if (!tx_enabled(port)) {
 		if (port->flags & UPF_CONS_FLOW)
 			s3c24xx_serial_rx_disable(port);
 
-		if (s3c24xx_serial_has_interrupt_mask(port))
-			__clear_bit(S3C64XX_UINTM_TXD,
-				portaddrl(port, S3C64XX_UINTM));
-		else
-			enable_irq(ourport->tx_irq);
 		tx_enabled(port) = 1;
+		if (!ourport->dma || !ourport->dma->tx_chan)
+			s3c24xx_serial_start_tx_pio(ourport);
 	}
+
+	if (ourport->dma && ourport->dma->tx_chan) {
+		if (!uart_circ_empty(xmit) && !ourport->tx_in_progress)
+			s3c24xx_serial_start_next_tx(ourport);
+	}
+}
+
+static void s3c24xx_uart_copy_rx_to_tty(struct s3c24xx_uart_port *ourport,
+		struct tty_port *tty, int count)
+{
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	int copied;
+
+	if (!count)
+		return;
+
+	dma_sync_single_for_cpu(ourport->port.dev, dma->rx_addr,
+				dma->rx_size, DMA_FROM_DEVICE);
+
+	ourport->port.icount.rx += count;
+	if (!tty) {
+		dev_err(ourport->port.dev, "No tty port\n");
+		return;
+	}
+	copied = tty_insert_flip_string(tty,
+			((unsigned char *)(ourport->dma->rx_buf)), count);
+	if (copied != count) {
+		WARN_ON(1);
+		dev_err(ourport->port.dev, "RxData copy to tty layer failed\n");
+	}
+}
+
+static int s3c24xx_serial_rx_fifocnt(struct s3c24xx_uart_port *ourport,
+				     unsigned long ufstat);
+
+static void uart_rx_drain_fifo(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	struct tty_port *tty = &port->state->port;
+	unsigned int ch, ufstat;
+	unsigned int count;
+
+	ufstat = rd_regl(port, S3C2410_UFSTAT);
+	count = s3c24xx_serial_rx_fifocnt(ourport, ufstat);
+
+	if (!count)
+		return;
+
+	while (count-- > 0) {
+		ch = rd_regb(port, S3C2410_URXH);
+
+		ourport->port.icount.rx++;
+		tty_insert_flip_char(tty, ch, TTY_NORMAL);
+	}
+
+	tty_flip_buffer_push(tty);
 }
 
 static void s3c24xx_serial_stop_rx(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct tty_port *t = &port->state->port;
+	struct dma_tx_state state;
+	enum dma_status dma_status;
+	unsigned int received;
 
 	if (rx_enabled(port)) {
 		dbg("s3c24xx_serial_stop_rx: port=%p\n", port);
···
 		else
 			disable_irq_nosync(ourport->rx_irq);
 		rx_enabled(port) = 0;
+	}
+	if (dma && dma->rx_chan) {
+		dmaengine_pause(dma->tx_chan);
+		dma_status = dmaengine_tx_status(dma->rx_chan,
+				dma->rx_cookie, &state);
+		if (dma_status == DMA_IN_PROGRESS ||
+			dma_status == DMA_PAUSED) {
+			received = dma->rx_bytes_requested - state.residue;
+			dmaengine_terminate_all(dma->rx_chan);
+			s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
+		}
 	}
 }
 
···
 	return (ufstat & info->rx_fifomask) >> info->rx_fifoshift;
 }
 
+static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport);
+static void s3c24xx_serial_rx_dma_complete(void *args)
+{
+	struct s3c24xx_uart_port *ourport = args;
+	struct uart_port *port = &ourport->port;
+
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct tty_port *t = &port->state->port;
+	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
+
+	struct dma_tx_state state;
+	unsigned long flags;
+	int received;
+
+	dmaengine_tx_status(dma->rx_chan,  dma->rx_cookie, &state);
+	received  = dma->rx_bytes_requested - state.residue;
+	async_tx_ack(dma->rx_desc);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (received)
+		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
+
+	if (tty) {
+		tty_flip_buffer_push(t);
+		tty_kref_put(tty);
+	}
+
+	s3c64xx_start_rx_dma(ourport);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport)
+{
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+
+	dma_sync_single_for_device(ourport->port.dev, dma->rx_addr,
+				dma->rx_size, DMA_FROM_DEVICE);
+
+	dma->rx_desc = dmaengine_prep_slave_single(dma->rx_chan,
+				dma->rx_addr, dma->rx_size, DMA_DEV_TO_MEM,
+				DMA_PREP_INTERRUPT);
+	if (!dma->rx_desc) {
+		dev_err(ourport->port.dev, "Unable to get desc for Rx\n");
+		return;
+	}
+
+	dma->rx_desc->callback = s3c24xx_serial_rx_dma_complete;
+	dma->rx_desc->callback_param = ourport;
+	dma->rx_bytes_requested = dma->rx_size;
+
+	dma->rx_cookie = dmaengine_submit(dma->rx_desc);
+	dma_async_issue_pending(dma->rx_chan);
+}
 
 /* ? - where has parity gone?? */
 #define S3C2410_UERSTAT_PARITY (0x1000)
 
-static irqreturn_t
-s3c24xx_serial_rx_chars(int irq, void *dev_id)
+static void enable_rx_dma(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	unsigned int ucon;
+
+	/* set Rx mode to DMA mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_RXBURST_MASK |
+			S3C64XX_UCON_TIMEOUT_MASK |
+			S3C64XX_UCON_EMPTYINT_EN |
+			S3C64XX_UCON_DMASUS_EN |
+			S3C64XX_UCON_TIMEOUT_EN |
+			S3C64XX_UCON_RXMODE_MASK);
+	ucon |= S3C64XX_UCON_RXBURST_16 |
+			0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
+			S3C64XX_UCON_EMPTYINT_EN |
+			S3C64XX_UCON_TIMEOUT_EN |
+			S3C64XX_UCON_RXMODE_DMA;
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	ourport->rx_mode = S3C24XX_RX_DMA;
+}
+
+static void enable_rx_pio(struct s3c24xx_uart_port *ourport)
+{
+	struct uart_port *port = &ourport->port;
+	unsigned int ucon;
+
+	/* set Rx mode to DMA mode */
+	ucon = rd_regl(port, S3C2410_UCON);
+	ucon &= ~(S3C64XX_UCON_TIMEOUT_MASK |
+			S3C64XX_UCON_EMPTYINT_EN |
+			S3C64XX_UCON_DMASUS_EN |
+			S3C64XX_UCON_TIMEOUT_EN |
+			S3C64XX_UCON_RXMODE_MASK);
+	ucon |= 0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
+			S3C64XX_UCON_TIMEOUT_EN |
+			S3C64XX_UCON_RXMODE_CPU;
+	wr_regl(port, S3C2410_UCON, ucon);
+
+	ourport->rx_mode = S3C24XX_RX_PIO;
+}
+
+static irqreturn_t s3c24xx_serial_rx_chars_dma(int irq, void *dev_id)
+{
+	unsigned int utrstat, ufstat, received;
+	struct s3c24xx_uart_port *ourport = dev_id;
+	struct uart_port *port = &ourport->port;
+	struct s3c24xx_uart_dma *dma = ourport->dma;
+	struct tty_struct *tty = tty_port_tty_get(&ourport->port.state->port);
+	struct tty_port *t = &port->state->port;
+	unsigned long flags;
+	struct dma_tx_state state;
+
+	utrstat = rd_regl(port, S3C2410_UTRSTAT);
+	ufstat = rd_regl(port, S3C2410_UFSTAT);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) {
+		s3c64xx_start_rx_dma(ourport);
+		if (ourport->rx_mode == S3C24XX_RX_PIO)
+			enable_rx_dma(ourport);
+		goto finish;
+	}
+
+	if (ourport->rx_mode == S3C24XX_RX_DMA) {
+		dmaengine_pause(dma->rx_chan);
+		dmaengine_tx_status(dma->rx_chan, dma->rx_cookie, &state);
+		dmaengine_terminate_all(dma->rx_chan);
+		received = dma->rx_bytes_requested - state.residue;
+		s3c24xx_uart_copy_rx_to_tty(ourport, t, received);
+
+		enable_rx_pio(ourport);
+	}
+
+	uart_rx_drain_fifo(ourport);
+
+	if (tty) {
+		tty_flip_buffer_push(t);
+		tty_kref_put(tty);
+	}
+
+	wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT);
+
+finish:
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t s3c24xx_serial_rx_chars_pio(int irq, void *dev_id)
 {
 	struct s3c24xx_uart_port *ourport = dev_id;
 	struct uart_port *port = &ourport->port;
···
 	return IRQ_HANDLED;
 }
 
+
+static irqreturn_t s3c24xx_serial_rx_chars(int irq, void *dev_id)
+{
+	struct s3c24xx_uart_port *ourport = dev_id;
+
+	if (ourport->dma && ourport->dma->rx_chan)
+		return s3c24xx_serial_rx_chars_dma(irq, dev_id);
+	return s3c24xx_serial_rx_chars_pio(irq, dev_id);
+}
+
 static irqreturn_t s3c24xx_serial_tx_chars(int irq, void *id)
 {
 	struct s3c24xx_uart_port *ourport = id;
 	struct uart_port *port = &ourport->port;
 	struct circ_buf *xmit = &port->state->xmit;
 	unsigned long flags;
-	int count = port->fifosize;
+	int count;
 
 	spin_lock_irqsave(&port->lock, flags);
+
+	count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+
+	if (ourport->dma && ourport->dma->tx_chan && count >= port->fifosize) {
+		s3c24xx_serial_start_tx_dma(ourport, count);
+		goto out;
+	}
 
 	if (port->x_char) {
 		wr_regb(port, S3C2410_UTXH, port->x_char);
···
 
 	/* try and drain the buffer... */
 
+	count = port->fifosize;
 	while (!uart_circ_empty(xmit) && count-- > 0) {
 		if (rd_regl(port, S3C2410_UFSTAT) & ourport->info->tx_fifofull)
 			break;
···
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
+static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
+{
+	struct s3c24xx_uart_dma	*dma = p->dma;
+	dma_cap_mask_t mask;
+	unsigned long flags;
+
+	/* Default slave configuration parameters */
+	dma->rx_conf.direction		= DMA_DEV_TO_MEM;
+	dma->rx_conf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma->rx_conf.src_addr		= p->port.mapbase + S3C2410_URXH;
+	dma->rx_conf.src_maxburst	= 16;
+
+	dma->tx_conf.direction		= DMA_MEM_TO_DEV;
+	dma->tx_conf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
+	dma->tx_conf.dst_addr		= p->port.mapbase + S3C2410_UTXH;
+	if (dma_get_cache_alignment() >= 16)
+		dma->tx_conf.dst_maxburst = 16;
+	else
+		dma->tx_conf.dst_maxburst = 1;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	dma->rx_chan = dma_request_slave_channel_compat(mask, dma->fn,
+					dma->rx_param, p->port.dev, "rx");
+	if (!dma->rx_chan)
+		return -ENODEV;
+
+	dmaengine_slave_config(dma->rx_chan, &dma->rx_conf);
+
+	dma->tx_chan = dma_request_slave_channel_compat(mask, dma->fn,
+					dma->tx_param, p->port.dev, "tx");
+	if (!dma->tx_chan) {
+		dma_release_channel(dma->rx_chan);
+		return -ENODEV;
+	}
+
+	dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
+
+	/* RX buffer */
+	dma->rx_size = PAGE_SIZE;
+
+	dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
+
+	if (!dma->rx_buf) {
+		dma_release_channel(dma->rx_chan);
+		dma_release_channel(dma->tx_chan);
+		return -ENOMEM;
+	}
+
+	dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf,
+				dma->rx_size, DMA_FROM_DEVICE);
+
+	spin_lock_irqsave(&p->port.lock, flags);
+
+	/* TX buffer */
+	dma->tx_addr = dma_map_single(dma->tx_chan->device->dev,
+				p->port.state->xmit.buf,
+				UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+	spin_unlock_irqrestore(&p->port.lock, flags);
+
+	return 0;
+}
+
+static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
+{
+	struct s3c24xx_uart_dma	*dma = p->dma;
+
+	if (dma->rx_chan) {
+		dmaengine_terminate_all(dma->rx_chan);
+		dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr,
+				dma->rx_size, DMA_FROM_DEVICE);
+		kfree(dma->rx_buf);
+		dma_release_channel(dma->rx_chan);
+		dma->rx_chan = NULL;
+	}
+
+	if (dma->tx_chan) {
+		dmaengine_terminate_all(dma->tx_chan);
+		dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr,
+				UART_XMIT_SIZE, DMA_TO_DEVICE);
+		dma_release_channel(dma->tx_chan);
+		dma->tx_chan = NULL;
+	}
+}
+
 static void s3c24xx_serial_shutdown(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
···
 		wr_regl(port, S3C64XX_UINTP, 0xf);
 		wr_regl(port, S3C64XX_UINTM, 0xf);
 	}
+
+	if (ourport->dma)
+		s3c24xx_serial_release_dma(ourport);
+
+	ourport->tx_in_progress = 0;
 }
 
 static int s3c24xx_serial_startup(struct uart_port *port)
···
 static int s3c64xx_serial_startup(struct uart_port *port)
 {
 	struct s3c24xx_uart_port *ourport = to_ourport(port);
+	unsigned long flags;
+	unsigned int ufcon;
 	int ret;
 
 	dbg("s3c64xx_serial_startup: port=%p (%08llx,%p)\n",
 	    port, (unsigned long long)port->mapbase, port->membase);
 
 	wr_regl(port, S3C64XX_UINTM, 0xf);
+	if (ourport->dma) {
+		ret = s3c24xx_serial_request_dma(ourport);
+		if (ret < 0) {
+			dev_warn(port->dev, "DMA request failed\n");
+			return ret;
+		}
+	}
 
 	ret = request_irq(port->irq, s3c64xx_serial_handle_irq, IRQF_SHARED,
 			  s3c24xx_serial_portname(port), ourport);
···
 	tx_enabled(port) = 0;
 	ourport->tx_claimed = 1;
 
+	spin_lock_irqsave(&port->lock, flags);
+
+	ufcon = rd_regl(port, S3C2410_UFCON);
+	ufcon |= S3C2410_UFCON_RESETRX | S3C2410_UFCON_RESETTX |
+			S5PV210_UFCON_RXTRIG8;
+	wr_regl(port, S3C2410_UFCON, ufcon);
+
+	enable_rx_pio(ourport);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
 	/* Enable Rx Interrupt */
 	__clear_bit(S3C64XX_UINTM_RXD, portaddrl(port, S3C64XX_UINTM));
+
 	dbg("s3c64xx_serial_startup ok\n");
 	return ret;
 }
···
 	ret = platform_get_irq(platdev, 1);
 	if (ret > 0)
 		ourport->tx_irq = ret;
+	/*
+	 * DMA is currently supported only on DT platforms, if DMA properties
+	 * are specified.
+	 */
+	if (platdev->dev.of_node && of_find_property(platdev->dev.of_node,
+						     "dmas", NULL)) {
+		ourport->dma = devm_kzalloc(port->dev,
+					    sizeof(*ourport->dma),
+					    GFP_KERNEL);
+		if (!ourport->dma)
+			return -ENOMEM;
+	}
 
 	ourport->clk	= clk_get(&platdev->dev, "uart");
 	if (IS_ERR(ourport->clk)) {
···
 };
 
 module_platform_driver(samsung_serial_driver);
+
+#ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
+/*
+ * Early console.
+ */
+
+struct samsung_early_console_data {
+	u32 txfull_mask;
+};
+
+static void samsung_early_busyuart(struct uart_port *port)
+{
+	while (!(readl(port->membase + S3C2410_UTRSTAT) & S3C2410_UTRSTAT_TXFE))
+		;
+}
+
+static void samsung_early_busyuart_fifo(struct uart_port *port)
+{
+	struct samsung_early_console_data *data = port->private_data;
+
+	while (readl(port->membase + S3C2410_UFSTAT) & data->txfull_mask)
+		;
+}
+
+static void samsung_early_putc(struct uart_port *port, int c)
+{
+	if (readl(port->membase + S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE)
+		samsung_early_busyuart_fifo(port);
+	else
+		samsung_early_busyuart(port);
+
+	writeb(c, port->membase + S3C2410_UTXH);
+}
+
+static void samsung_early_write(struct console *con, const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, samsung_early_putc);
+}
+
+static int __init samsung_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = samsung_early_write;
+	return 0;
+}
+
+/* S3C2410 */
+static struct samsung_early_console_data s3c2410_early_console_data = {
+	.txfull_mask = S3C2410_UFSTAT_TXFULL,
+};
+
+static int __init s3c2410_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	device->port.private_data = &s3c2410_early_console_data;
+	return samsung_early_console_setup(device, opt);
+}
+OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart",
+			s3c2410_early_console_setup);
+EARLYCON_DECLARE(s3c2410, s3c2410_early_console_setup);
+
+/* S3C2412, S3C2440, S3C64xx */
+static struct samsung_early_console_data s3c2440_early_console_data = {
+	.txfull_mask = S3C2440_UFSTAT_TXFULL,
+};
+
+static int __init s3c2440_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	device->port.private_data = &s3c2440_early_console_data;
+	return samsung_early_console_setup(device, opt);
+}
+OF_EARLYCON_DECLARE(s3c2412, "samsung,s3c2412-uart",
+			s3c2440_early_console_setup);
+OF_EARLYCON_DECLARE(s3c2440, "samsung,s3c2440-uart",
+			s3c2440_early_console_setup);
+OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart",
+			s3c2440_early_console_setup);
+EARLYCON_DECLARE(s3c2412, s3c2440_early_console_setup);
+EARLYCON_DECLARE(s3c2440, s3c2440_early_console_setup);
+EARLYCON_DECLARE(s3c6400, s3c2440_early_console_setup);
+
+/* S5PV210, EXYNOS */
+static struct samsung_early_console_data s5pv210_early_console_data = {
+	.txfull_mask = S5PV210_UFSTAT_TXFULL,
+};
+
+static int __init s5pv210_early_console_setup(struct earlycon_device *device,
+					      const char *opt)
+{
+	device->port.private_data = &s5pv210_early_console_data;
+	return samsung_early_console_setup(device, opt);
+}
+OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
+			s5pv210_early_console_setup);
+OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
+			s5pv210_early_console_setup);
+EARLYCON_DECLARE(s5pv210, s5pv210_early_console_setup);
+EARLYCON_DECLARE(exynos4210, s5pv210_early_console_setup);
+#endif
 
 MODULE_ALIAS("platform:samsung-uart");
 MODULE_DESCRIPTION("Samsung SoC Serial port driver");

drivers/tty/serial/samsung.h

···
  * published by the Free Software Foundation.
 */
 
+#include <linux/dmaengine.h>
+
 struct s3c24xx_uart_info {
 	char			*name;
 	unsigned int		type;
···
 	unsigned int			fifosize[CONFIG_SERIAL_SAMSUNG_UARTS];
 };
 
+struct s3c24xx_uart_dma {
+	dma_filter_fn			fn;
+	void				*rx_param;
+	void				*tx_param;
+
+	unsigned int			rx_chan_id;
+	unsigned int			tx_chan_id;
+
+	struct dma_slave_config		rx_conf;
+	struct dma_slave_config		tx_conf;
+
+	struct dma_chan			*rx_chan;
+	struct dma_chan			*tx_chan;
+
+	dma_addr_t			rx_addr;
+	dma_addr_t			tx_addr;
+
+	dma_cookie_t			rx_cookie;
+	dma_cookie_t			tx_cookie;
+
+	char				*rx_buf;
+
+	dma_addr_t			tx_transfer_addr;
+
+	size_t				rx_size;
+	size_t				tx_size;
+
+	struct dma_async_tx_descriptor	*tx_desc;
+	struct dma_async_tx_descriptor	*rx_desc;
+
+	int				tx_bytes_requested;
+	int				rx_bytes_requested;
+};
+
 struct s3c24xx_uart_port {
 	unsigned char			rx_claimed;
 	unsigned char			tx_claimed;
···
 	unsigned int			rx_irq;
 	unsigned int			tx_irq;
 
+	unsigned int			tx_in_progress;
+	unsigned int			tx_mode;
+	unsigned int			rx_mode;
+
 	struct s3c24xx_uart_info	*info;
 	struct clk			*clk;
 	struct clk			*baudclk;
···
 
 	/* reference to platform data */
 	struct s3c2410_uartcfg		*cfg;
+
+	struct s3c24xx_uart_dma		*dma;
 
 #ifdef CONFIG_CPU_FREQ
 	struct notifier_block		freq_transition;

drivers/tty/serial/serial_core.c

···
 			if (tty->termios.c_cflag & CBAUD)
 				uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
 		}
-
-		spin_lock_irq(&uport->lock);
-		if (uart_cts_enabled(uport) &&
-		    !(uport->ops->get_mctrl(uport) & TIOCM_CTS))
-			uport->hw_stopped = 1;
-		else
-			uport->hw_stopped = 0;
-		spin_unlock_irq(&uport->lock);
 	}
 
 	/*
···
 {
 	struct uart_port *uport = state->uart_port;
 	struct ktermios *termios;
+	int hw_stopped;
 
 	/*
 	 * If we have no tty, termios, or the port does not exist,
···
 		uport->status &= ~UPSTAT_DCD_ENABLE;
 	else
 		uport->status |= UPSTAT_DCD_ENABLE;
+
+	/* reset sw-assisted CTS flow control based on (possibly) new mode */
+	hw_stopped = uport->hw_stopped;
+	uport->hw_stopped = uart_softcts_mode(uport) &&
+				!(uport->ops->get_mctrl(uport) & TIOCM_CTS);
+	if (uport->hw_stopped) {
+		if (!hw_stopped)
+			uport->ops->stop_tx(uport);
+	} else {
+		if (hw_stopped)
+			__uart_start(tty);
+	}
 	spin_unlock_irq(&uport->lock);
 }
 
···
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
-	upf_t mask = 0;
+	upstat_t mask = 0;
 
 	if (I_IXOFF(tty))
-		mask |= UPF_SOFT_FLOW;
+		mask |= UPSTAT_AUTOXOFF;
 	if (tty->termios.c_cflag & CRTSCTS)
-		mask |= UPF_HARD_FLOW;
+		mask |= UPSTAT_AUTORTS;
 
-	if (port->flags & mask) {
+	if (port->status & mask) {
 		port->ops->throttle(port);
-		mask &= ~port->flags;
+		mask &= ~port->status;
 	}
 
-	if (mask & UPF_SOFT_FLOW)
+	if (mask & UPSTAT_AUTOXOFF)
 		uart_send_xchar(tty, STOP_CHAR(tty));
 
-	if (mask & UPF_HARD_FLOW)
+	if (mask & UPSTAT_AUTORTS)
 		uart_clear_mctrl(port, TIOCM_RTS);
 }
 
···
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
-	upf_t mask = 0;
+	upstat_t mask = 0;
 
 	if (I_IXOFF(tty))
-		mask |= UPF_SOFT_FLOW;
+		mask |= UPSTAT_AUTOXOFF;
 	if (tty->termios.c_cflag & CRTSCTS)
-		mask |= UPF_HARD_FLOW;
+		mask |= UPSTAT_AUTORTS;
 
-	if (port->flags & mask) {
+	if (port->status & mask) {
 		port->ops->unthrottle(port);
-		mask &= ~port->flags;
+		mask &= ~port->status;
 	}
 
-	if (mask & UPF_SOFT_FLOW)
+	if (mask & UPSTAT_AUTOXOFF)
 		uart_send_xchar(tty, START_CHAR(tty));
 
-	if (mask & UPF_HARD_FLOW)
+	if (mask & UPSTAT_AUTORTS)
 		uart_set_mctrl(port, TIOCM_RTS);
 }
 
···
 			mask |= TIOCM_RTS;
 		uart_set_mctrl(uport, mask);
 	}
-
-	/*
-	 * If the port is doing h/w assisted flow control, do nothing.
-	 * We assume that port->hw_stopped has never been set.
-	 */
-	if (uport->flags & UPF_HARD_FLOW)
-		return;
-
-	/* Handle turning off CRTSCTS */
-	if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
-		spin_lock_irq(&uport->lock);
-		uport->hw_stopped = 0;
-		__uart_start(tty);
-		spin_unlock_irq(&uport->lock);
-	}
-	/* Handle turning on CRTSCTS */
-	else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
-		spin_lock_irq(&uport->lock);
-		if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) {
-			uport->hw_stopped = 1;
-			uport->ops->stop_tx(uport);
-		}
-		spin_unlock_irq(&uport->lock);
-	}
 }
 
 /*
···
 	}
 	put_device(tty_dev);
 
-	if (console_suspend_enabled || !uart_console(uport))
-		uport->suspended = 1;
+	/* Nothing to do if the console is not suspending */
+	if (!console_suspend_enabled && uart_console(uport))
+		goto unlock;
+
+	uport->suspended = 1;
 
 	if (port->flags & ASYNC_INITIALIZED) {
 		const struct uart_ops *ops = uport->ops;
 		int tries;
 
-		if (console_suspend_enabled || !uart_console(uport)) {
-			set_bit(ASYNCB_SUSPENDED, &port->flags);
-			clear_bit(ASYNCB_INITIALIZED, &port->flags);
+		set_bit(ASYNCB_SUSPENDED, &port->flags);
+		clear_bit(ASYNCB_INITIALIZED, &port->flags);
 
-			spin_lock_irq(&uport->lock);
-			ops->stop_tx(uport);
-			ops->set_mctrl(uport, 0);
-			ops->stop_rx(uport);
-			spin_unlock_irq(&uport->lock);
-		}
+		spin_lock_irq(&uport->lock);
+		ops->stop_tx(uport);
+		ops->set_mctrl(uport, 0);
+		ops->stop_rx(uport);
+		spin_unlock_irq(&uport->lock);
 
 		/*
 		 * Wait for the transmitter to empty.
···
 				drv->dev_name,
 				drv->tty_driver->name_base + uport->line);
 
-		if (console_suspend_enabled || !uart_console(uport))
-			ops->shutdown(uport);
+		ops->shutdown(uport);
 	}
 
 	/*
 	 * Disable the console device before suspending.
 	 */
-	if (console_suspend_enabled && uart_console(uport))
+	if (uart_console(uport))
 		console_stop(uport->cons);
 
-	if (console_suspend_enabled || !uart_console(uport))
-		uart_change_pm(state, UART_PM_STATE_OFF);
-
+	uart_change_pm(state, UART_PM_STATE_OFF);
+unlock:
 	mutex_unlock(&port->mutex);
 
 	return 0;
···
 
 	uport->icount.cts++;
 
-	if (uart_cts_enabled(uport)) {
+	if (uart_softcts_mode(uport)) {
 		if (uport->hw_stopped) {
 			if (status) {
 				uport->hw_stopped = 0;
···
 				uport->ops->stop_tx(uport);
 			}
 		}
+
 	}
 }
 EXPORT_SYMBOL_GPL(uart_handle_cts_change);

drivers/tty/serial/sh-sci.c

···
 		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 		tty_flip_buffer_push(tport);
 
-		dev_notice(port->dev, "overrun error\n");
+		dev_dbg(port->dev, "overrun error\n");
 		copied++;
 	}
 
···
 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
 {
 	unsigned short ssr_status, scr_status, err_enabled;
+	unsigned short slr_status = 0;
 	struct uart_port *port = ptr;
 	struct sci_port *s = to_sci_port(port);
 	irqreturn_t ret = IRQ_NONE;
 
 	ssr_status = serial_port_in(port, SCxSR);
 	scr_status = serial_port_in(port, SCSCR);
+	if (port->type == PORT_SCIF || port->type == PORT_HSCIF)
+		slr_status = serial_port_in(port, SCLSR);
 	err_enabled = scr_status & port_rx_irq_mask(port);
 
 	/* Tx Interrupt */
···
 	 * DR flags
 	 */
 	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
-	    (scr_status & SCSCR_RIE))
+	    (scr_status & SCSCR_RIE)) {
+		if (port->type == PORT_SCIF || port->type == PORT_HSCIF)
+			sci_handle_fifo_overrun(port);
 		ret = sci_rx_interrupt(irq, ptr);
+	}
 
 	/* Error Interrupt */
 	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
···
 	/* Break Interrupt */
 	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
 		ret = sci_br_interrupt(irq, ptr);
+
+	/* Overrun Interrupt */
+	if (port->type == PORT_SCIF || port->type == PORT_HSCIF) {
+		if (slr_status & 0x01)
+			sci_handle_fifo_overrun(port);
+	}
 
 	return ret;
 }
···
 	return 0;
 }
 
-static int sci_suspend(struct device *dev)
+static __maybe_unused int sci_suspend(struct device *dev)
 {
 	struct sci_port *sport = dev_get_drvdata(dev);
 
···
 	return 0;
 }
 
-static int sci_resume(struct device *dev)
+static __maybe_unused int sci_resume(struct device *dev)
 {
 	struct sci_port *sport = dev_get_drvdata(dev);
 
···
 	return 0;
 }
 
-static const struct dev_pm_ops sci_dev_pm_ops = {
-	.suspend	= sci_suspend,
-	.resume		= sci_resume,
-};
+static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
 
 static struct platform_driver sci_driver = {
 	.probe		= sci_probe,

drivers/tty/serial/sirfsoc_uart.c

···
 			dmaengine_pause(sirfport->tx_dma_chan);
 			sirfport->tx_dma_state = TX_DMA_PAUSE;
 		} else {
-			if (!sirfport->is_marco)
+			if (!sirfport->is_atlas7)
 				wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) &
 				~uint_en->sirfsoc_txfifo_empty_en);
···
 				uint_en->sirfsoc_txfifo_empty_en);
 		}
 	} else {
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) &
 				~uint_en->sirfsoc_txfifo_empty_en);
···
 	}
 	if (sirfport->tx_dma_state == TX_DMA_RUNNING)
 		return;
-	if (!sirfport->is_marco)
+	if (!sirfport->is_atlas7)
 		wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg)&
 				~(uint_en->sirfsoc_txfifo_empty_en));
···
 		}
 		if (tran_size < 4)
 			sirfsoc_uart_pio_tx_chars(sirfport, tran_size);
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg)|
 				uint_en->sirfsoc_txfifo_empty_en);
···
 		sirfsoc_uart_pio_tx_chars(sirfport,
 			SIRFSOC_UART_IO_TX_REASONABLE_CNT);
 		wr_regl(port, ureg->sirfsoc_tx_fifo_op, SIRFUART_FIFO_START);
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 					rd_regl(port, ureg->sirfsoc_int_en_reg)|
 					uint_en->sirfsoc_txfifo_empty_en);
···
 
 	wr_regl(port, ureg->sirfsoc_rx_fifo_op, 0);
 	if (sirfport->rx_dma_chan) {
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) &
 				~(SIRFUART_RX_DMA_INT_EN(port, uint_en) |
···
 					uint_en->sirfsoc_rx_done_en);
 		dmaengine_terminate_all(sirfport->rx_dma_chan);
 	} else {
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg)&
 				~(SIRFUART_RX_IO_INT_EN(port, uint_en)));
···
 	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
 		wr_regl(port, ureg->sirfsoc_afc_ctrl,
 				rd_regl(port, ureg->sirfsoc_afc_ctrl) & ~0x3FF);
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 					rd_regl(port, ureg->sirfsoc_int_en_reg)&
 					~uint_en->sirfsoc_cts_en);
···
 		wr_regl(port, ureg->sirfsoc_afc_ctrl,
 				rd_regl(port, ureg->sirfsoc_afc_ctrl) |
 				SIRFUART_AFC_TX_EN | SIRFUART_AFC_RX_EN);
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 					rd_regl(port, ureg->sirfsoc_int_en_reg)
 					| uint_en->sirfsoc_cts_en);
···
 		sirfport->rx_io_count = 0;
 		wr_regl(port, ureg->sirfsoc_int_st_reg,
 				uint_st->sirfsoc_rx_done);
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) &
 				~(uint_en->sirfsoc_rx_done_en));
···
 	} else {
 		wr_regl(port, ureg->sirfsoc_int_st_reg,
 				uint_st->sirfsoc_rx_done);
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) |
 				(uint_en->sirfsoc_rx_done_en));
···
 	dmaengine_terminate_all(sirfport->rx_dma_chan);
 	sirfport->rx_dma_items[sirfport->rx_issued].xmit.head =
 		SIRFSOC_RX_DMA_BUF_SIZE - tx_state.residue;
-	if (!sirfport->is_marco)
+	if (!sirfport->is_atlas7)
 		wr_regl(port, ureg->sirfsoc_int_en_reg,
 			rd_regl(port, ureg->sirfsoc_int_en_reg) &
 			~(uint_en->sirfsoc_rx_timeout_en));
···
 	sirfsoc_uart_pio_rx_chars(port, 4 - sirfport->rx_io_count);
 	if (sirfport->rx_io_count == 4) {
 		sirfport->rx_io_count = 0;
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) &
 				~(uint_en->sirfsoc_rx_done_en));
···
 	for (i = 0; i < SIRFSOC_RX_LOOP_BUF_CNT; i++)
 		sirfsoc_rx_submit_one_dma_desc(port, i);
 	sirfport->rx_completed = sirfport->rx_issued = 0;
-	if (!sirfport->is_marco)
+	if (!sirfport->is_atlas7)
 		wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) |
 				SIRFUART_RX_DMA_INT_EN(port, uint_en));
···
 	if (sirfport->rx_dma_chan)
 		sirfsoc_uart_start_next_rx_dma(port);
 	else {
-		if (!sirfport->is_marco)
+		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 				rd_regl(port, ureg->sirfsoc_int_en_reg) |
 				SIRFUART_RX_IO_INT_EN(port, uint_en));
···
 {
 	struct sirfsoc_uart_port *sirfport = to_sirfport(port);
 	struct sirfsoc_register *ureg = &sirfport->uart_reg->uart_reg;
-	if (!sirfport->is_marco)
+	if (!sirfport->is_atlas7)
 		wr_regl(port, ureg->sirfsoc_int_en_reg, 0);
 	else
 		wr_regl(port, SIRFUART_INT_EN_CLR, ~0UL);
···
 
 static struct of_device_id sirfsoc_uart_ids[] = {
 	{ .compatible = "sirf,prima2-uart", .data = &sirfsoc_uart,},
-	{ .compatible = "sirf,marco-uart", .data = &sirfsoc_uart},
+	{ .compatible = "sirf,atlas7-uart", .data = &sirfsoc_uart},
 	{ .compatible = "sirf,prima2-usp-uart", .data = &sirfsoc_usp},
 	{}
 };
···
 		gpio_direction_output(sirfport->rts_gpio, 1);
 	}
 usp_no_flow_control:
-	if (of_device_is_compatible(pdev->dev.of_node, "sirf,marco-uart"))
-		sirfport->is_marco = true;
+	if (of_device_is_compatible(pdev->dev.of_node, "sirf,atlas7-uart"))
+		sirfport->is_atlas7 = true;
 
 	if (of_property_read_u32(pdev->dev.of_node,
 			"fifosize",
···
 		goto err;
 	}
 	port->uartclk = clk_get_rate(sirfport->clk);
-	if (of_device_is_compatible(pdev->dev.of_node, "sirf,marco-bt-uart")) {
+	if (of_device_is_compatible(pdev->dev.of_node, "sirf,atlas7-bt-uart")) {
 		sirfport->clk_general = devm_clk_get(&pdev->dev, "general");
 		if (IS_ERR(sirfport->clk_general)) {
 			ret = PTR_ERR(sirfport->clk_general);

drivers/tty/serial/sirfsoc_uart.h

···
 	bool				is_bt_uart;
 	struct clk			*clk_general;
 	struct clk			*clk_noc;
-	/* for SiRFmarco, there are SET/CLR for UART_INT_EN */
-	bool				is_marco;
+	/* for SiRFatlas7, there are SET/CLR for UART_INT_EN */
+	bool				is_atlas7;
 	struct sirfsoc_uart_register	*uart_reg;
 	struct dma_chan			*rx_dma_chan;
 	struct dma_chan			*tx_dma_chan;

drivers/tty/serial/sprd_serial.c

···
+/*
+ * Copyright (C) 2012-2015 Spreadtrum Communications Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#if defined(CONFIG_SERIAL_SPRD_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+/* device name */
+#define UART_NR_MAX		8
+#define SPRD_TTY_NAME		"ttyS"
+#define SPRD_FIFO_SIZE		128
+#define SPRD_DEF_RATE		26000000
+#define SPRD_BAUD_IO_LIMIT	3000000
+#define SPRD_TIMEOUT		256
+
+/* the offset of serial registers and BITs for them */
+/* data registers */
+#define SPRD_TXD		0x0000
+#define SPRD_RXD		0x0004
+
+/* line status register and its BITs  */
+#define SPRD_LSR		0x0008
+#define SPRD_LSR_OE		BIT(4)
+#define SPRD_LSR_FE		BIT(3)
+#define SPRD_LSR_PE		BIT(2)
+#define SPRD_LSR_BI		BIT(7)
+#define SPRD_LSR_TX_OVER	BIT(15)
+
+/* data number in TX and RX fifo */
+#define SPRD_STS1		0x000C
+
+/* interrupt enable register and its BITs */
+#define SPRD_IEN		0x0010
+#define SPRD_IEN_RX_FULL	BIT(0)
+#define SPRD_IEN_TX_EMPTY	BIT(1)
+#define SPRD_IEN_BREAK_DETECT	BIT(7)
+#define SPRD_IEN_TIMEOUT	BIT(13)
+
+/* interrupt clear register */
+#define SPRD_ICLR		0x0014
+
+/* line control register */
+#define SPRD_LCR		0x0018
+#define SPRD_LCR_STOP_1BIT	0x10
+#define SPRD_LCR_STOP_2BIT	0x30
+#define SPRD_LCR_DATA_LEN	(BIT(2) | BIT(3))
+#define SPRD_LCR_DATA_LEN5	0x0
+#define SPRD_LCR_DATA_LEN6	0x4
+#define SPRD_LCR_DATA_LEN7	0x8
+#define SPRD_LCR_DATA_LEN8	0xc
+#define SPRD_LCR_PARITY	(BIT(0) | BIT(1))
+#define SPRD_LCR_PARITY_EN	0x2
+#define SPRD_LCR_EVEN_PAR	0x0
+#define SPRD_LCR_ODD_PAR	0x1
+
+/* control register 1 */
+#define SPRD_CTL1			0x001C
+#define RX_HW_FLOW_CTL_THLD	BIT(6)
+#define RX_HW_FLOW_CTL_EN	BIT(7)
+#define TX_HW_FLOW_CTL_EN	BIT(8)
+#define RX_TOUT_THLD_DEF	0x3E00
+#define RX_HFC_THLD_DEF	0x40
+
+/* fifo threshold register */
+#define SPRD_CTL2		0x0020
+#define THLD_TX_EMPTY	0x40
+#define THLD_RX_FULL	0x40
+
+/* config baud rate register */
+#define SPRD_CLKD0		0x0024
+#define SPRD_CLKD1		0x0028
+
+/* interrupt mask status register */
+#define SPRD_IMSR			0x002C
+#define SPRD_IMSR_RX_FIFO_FULL		BIT(0)
+#define SPRD_IMSR_TX_FIFO_EMPTY	BIT(1)
+#define SPRD_IMSR_BREAK_DETECT		BIT(7)
+#define SPRD_IMSR_TIMEOUT		BIT(13)
+
+struct reg_backup {
+	u32 ien;
+	u32 ctrl0;
+	u32 ctrl1;
+	u32 ctrl2;
+	u32 clkd0;
+	u32 clkd1;
+	u32 dspwait;
+};
+
+struct sprd_uart_port {
+	struct uart_port port;
+	struct reg_backup reg_bak;
+	char name[16];
+};
+
+static struct sprd_uart_port *sprd_port[UART_NR_MAX];
+static int sprd_ports_num;
+
+static inline unsigned int serial_in(struct uart_port *port, int offset)
+{
+	return readl_relaxed(port->membase + offset);
+}
+
+static inline void serial_out(struct uart_port *port, int offset, int value)
+{
+	writel_relaxed(value, port->membase + offset);
+}
+
+static unsigned int sprd_tx_empty(struct uart_port *port)
+{
+	if (serial_in(port, SPRD_STS1) & 0xff00)
+		return 0;
+	else
+		return TIOCSER_TEMT;
+}
+
+static unsigned int sprd_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_DSR | TIOCM_CTS;
+}
+
+static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* nothing to do */
+}
+
+static void sprd_stop_tx(struct uart_port *port)
+{
+	unsigned int ien, iclr;
+
+	iclr = serial_in(port, SPRD_ICLR);
+	ien = serial_in(port, SPRD_IEN);
+
+	iclr |= SPRD_IEN_TX_EMPTY;
+	ien &= ~SPRD_IEN_TX_EMPTY;
+
+	serial_out(port, SPRD_ICLR, iclr);
+	serial_out(port, SPRD_IEN, ien);
+}
+
+static void sprd_start_tx(struct uart_port *port)
+{
+	unsigned int ien;
+
+	ien = serial_in(port, SPRD_IEN);
+	if (!(ien & SPRD_IEN_TX_EMPTY)) {
+		ien |= SPRD_IEN_TX_EMPTY;
+		serial_out(port, SPRD_IEN, ien);
+	}
+}
+
+static void sprd_stop_rx(struct uart_port *port)
+{
+	unsigned int ien, iclr;
+
+	iclr = serial_in(port, SPRD_ICLR);
+	ien = serial_in(port, SPRD_IEN);
+
+	ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
+	iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
+
+	serial_out(port, SPRD_IEN, ien);
+	serial_out(port, SPRD_ICLR, iclr);
+}
+
+/* The Sprd serial does not support this function. */
+static void sprd_break_ctl(struct uart_port *port, int break_state)
+{
+	/* nothing to do */
+}
+
+static int handle_lsr_errors(struct uart_port *port,
+			     unsigned int *flag,
+			     unsigned int *lsr)
+{
+	int ret = 0;
+
+	/* statistics */
+	if (*lsr & SPRD_LSR_BI) {
+		*lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE);
+		port->icount.brk++;
+		ret = uart_handle_break(port);
+		if (ret)
+			return ret;
+	} else if (*lsr & SPRD_LSR_PE)
+		port->icount.parity++;
+	else if (*lsr & SPRD_LSR_FE)
+		port->icount.frame++;
+	if (*lsr & SPRD_LSR_OE)
+		port->icount.overrun++;
+
+	/* mask off conditions which should be ignored */
+	*lsr &= port->read_status_mask;
+	if (*lsr & SPRD_LSR_BI)
+		*flag = TTY_BREAK;
+	else if (*lsr & SPRD_LSR_PE)
+		*flag = TTY_PARITY;
+	else if (*lsr & SPRD_LSR_FE)
+		*flag = TTY_FRAME;
+
+	return ret;
+}
+
+static inline void sprd_rx(struct uart_port *port)
+{
+	struct tty_port *tty = &port->state->port;
+	unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT;
+
+	while ((serial_in(port, SPRD_STS1) & 0x00ff) && max_count--) {
+		lsr = serial_in(port, SPRD_LSR);
+		ch = serial_in(port, SPRD_RXD);
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE |
+			SPRD_LSR_FE | SPRD_LSR_OE))
+			if (handle_lsr_errors(port, &lsr, &flag))
+				continue;
+		if (uart_handle_sysrq_char(port, ch))
+			continue;
+
+		uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
+	}
+
+	tty_flip_buffer_push(tty);
+}
+
+static inline void sprd_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	int count;
+
+	if (port->x_char) {
+		serial_out(port, SPRD_TXD, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		sprd_stop_tx(port);
+		return;
+	}
+
+	count = THLD_TX_EMPTY;
+	do {
+		serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		sprd_stop_tx(port);
+}
+
+/* this handles the interrupt from one port */
+static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned int ims;
+
+	spin_lock(&port->lock);
+
+	ims = serial_in(port, SPRD_IMSR);
+
+	if (!ims)
+		return IRQ_NONE;
+
+	serial_out(port, SPRD_ICLR, ~0);
+
+	if (ims & (SPRD_IMSR_RX_FIFO_FULL |
+		SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT))
+		sprd_rx(port);
+
+	if (ims & SPRD_IMSR_TX_FIFO_EMPTY)
+		sprd_tx(port);
+
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int sprd_startup(struct uart_port *port)
+{
+	int ret = 0;
+	unsigned int ien, fc;
+	unsigned int timeout;
+	struct sprd_uart_port *sp;
+	unsigned long flags;
+
+	serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY << 8) | THLD_RX_FULL));
+
+	/* clear rx fifo */
+	timeout = SPRD_TIMEOUT;
+	while (timeout-- && serial_in(port, SPRD_STS1) & 0x00ff)
+		serial_in(port, SPRD_RXD);
+
+	/* clear tx fifo */
+	timeout = SPRD_TIMEOUT;
+	while (timeout-- && serial_in(port, SPRD_STS1) & 0xff00)
+		cpu_relax();
+
+	/* clear interrupt */
+	serial_out(port, SPRD_IEN, 0);
+	serial_out(port, SPRD_ICLR, ~0);
+
+	/* allocate irq */
+	sp = container_of(port, struct sprd_uart_port, port);
+	snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
+	ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
+				IRQF_SHARED, sp->name, port);
+	if (ret) {
+		dev_err(port->dev, "fail to request serial irq %d, ret=%d\n",
+			port->irq, ret);
+		return ret;
+	}
+	fc = serial_in(port, SPRD_CTL1);
+	fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
+	serial_out(port, SPRD_CTL1, fc);
+
+	/* enable interrupt */
+	spin_lock_irqsave(&port->lock, flags);
+	ien = serial_in(port, SPRD_IEN);
+	ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
+	serial_out(port, SPRD_IEN, ien);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 0;
+}
+
+static void sprd_shutdown(struct uart_port *port)
+{
+	serial_out(port, SPRD_IEN, 0);
+	serial_out(port, SPRD_ICLR, ~0);
+	devm_free_irq(port->dev, port->irq, port);
+}
+
+static void sprd_set_termios(struct uart_port *port,
+				    struct ktermios *termios,
+				    struct ktermios *old)
+{
+	unsigned int baud, quot;
+	unsigned int lcr = 0, fc;
+	unsigned long flags;
+
+	/* ask the core to calculate the divisor for us */
+	baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT);
+
+	quot = (unsigned int)((port->uartclk + baud / 2) / baud);
+
+	/* set data length */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		lcr |= SPRD_LCR_DATA_LEN5;
+		break;
+	case CS6:
+		lcr |= SPRD_LCR_DATA_LEN6;
+		break;
+	case CS7:
+		lcr |= SPRD_LCR_DATA_LEN7;
+		break;
+	case CS8:
+	default:
+		lcr |= SPRD_LCR_DATA_LEN8;
+		break;
+	}
+
+	/* calculate stop bits */
+	lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
+	if (termios->c_cflag & CSTOPB)
+		lcr |= SPRD_LCR_STOP_2BIT;
+	else
+		lcr |= SPRD_LCR_STOP_1BIT;
+
+	/* calculate parity */
+	lcr &= ~SPRD_LCR_PARITY;
+	termios->c_cflag &= ~CMSPAR;	/* no support mark/space */
+	if (termios->c_cflag & PARENB) {
+		lcr |= SPRD_LCR_PARITY_EN;
+		if (termios->c_cflag & PARODD)
+			lcr |= SPRD_LCR_ODD_PAR;
+		else
+			lcr |= SPRD_LCR_EVEN_PAR;
+	}
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = SPRD_LSR_OE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= SPRD_LSR_BI;
+
+	/* characters to ignore */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= SPRD_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			port->ignore_status_mask |= SPRD_LSR_OE;
+	}
+
+	/* flow control */
+	fc = serial_in(port, SPRD_CTL1);
+	fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
+	if (termios->c_cflag & CRTSCTS) {
+		fc |= RX_HW_FLOW_CTL_THLD;
+		fc |= RX_HW_FLOW_CTL_EN;
+		fc |= TX_HW_FLOW_CTL_EN;
+	}
+
+	/* clock divider bit0~bit15 */
+	serial_out(port, SPRD_CLKD0, quot & 0xffff);
+
+	/* clock divider bit16~bit20 */
+	serial_out(port, SPRD_CLKD1, (quot & 0x1f0000) >> 16);
+	serial_out(port, SPRD_LCR, lcr);
+	fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF;
+	serial_out(port, SPRD_CTL1, fc);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *sprd_type(struct uart_port *port)
+{
+	return "SPX";
+}
+
+static void sprd_release_port(struct uart_port *port)
+{
+	/* nothing to do */
+}
+
+static int sprd_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sprd_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE)
+		port->type = PORT_SPRD;
+}
+
+static int sprd_verify_port(struct uart_port *port,
+				   struct serial_struct *ser)
+{
+	if (ser->type != PORT_SPRD)
+		return -EINVAL;
+	if (port->irq != ser->irq)
+		return -EINVAL;
+	return 0;
+}
+
+static struct uart_ops serial_sprd_ops = {
+	.tx_empty = sprd_tx_empty,
+	.get_mctrl = sprd_get_mctrl,
+	.set_mctrl = sprd_set_mctrl,
+	.stop_tx = sprd_stop_tx,
+	.start_tx = sprd_start_tx,
+	.stop_rx = sprd_stop_rx,
+	.break_ctl = sprd_break_ctl,
+	.startup = sprd_startup,
+	.shutdown = sprd_shutdown,
+	.set_termios = sprd_set_termios,
+	.type = sprd_type,
+	.release_port = sprd_release_port,
+	.request_port = sprd_request_port,
+	.config_port = sprd_config_port,
+	.verify_port = sprd_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_SPRD_CONSOLE
+static inline void wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int status, tmout = 10000;
+
+	/* wait up to 10ms for the character(s) to be sent */
+	do {
+		status = serial_in(port, SPRD_STS1);
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (status & 0xff00);
+}
+
+static void sprd_console_putchar(struct uart_port *port, int ch)
+{
+	wait_for_xmitr(port);
+	serial_out(port, SPRD_TXD, ch);
+}
+
+static void sprd_console_write(struct console *co, const char *s,
+				      unsigned int count)
+{
+	struct uart_port *port = &sprd_port[co->index]->port;
+	int locked = 1;
+	unsigned long flags;
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	uart_console_write(port, s, count, sprd_console_putchar);
+
+	/* wait for transmitter to become empty */
+	wait_for_xmitr(port);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int __init sprd_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= UART_NR_MAX || co->index < 0)
+		co->index = 0;
+
+	port = &sprd_port[co->index]->port;
+	if (port == NULL) {
+		pr_info("serial port %d not yet initialized\n", co->index);
+		return -ENODEV;
+	}
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sprd_uart_driver;
+static struct console sprd_console = {
+	.name = SPRD_TTY_NAME,
+	.write = sprd_console_write,
+	.device = uart_console_device,
+	.setup = sprd_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &sprd_uart_driver,
+};
+
+#define SPRD_CONSOLE	(&sprd_console)
+
+/* Support for earlycon */
+static void sprd_putc(struct uart_port *port, int c)
+{
+	unsigned int timeout = SPRD_TIMEOUT;
+
+	while (timeout-- &&
+		   !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER))
+		cpu_relax();
+
+	writeb(c, port->membase + SPRD_TXD);
+}
+
+static void sprd_early_write(struct console *con, const char *s,
+				    unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+
+	uart_console_write(&dev->port, s, n, sprd_putc);
+}
+
+static int __init sprd_early_console_setup(
+				struct earlycon_device *device,
+				const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = sprd_early_write;
+	return 0;
+}
+
+EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
+OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
+		    sprd_early_console_setup);
+
+#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
+#define SPRD_CONSOLE		NULL
+#endif
+
+static struct uart_driver sprd_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "sprd_serial",
+	.dev_name = SPRD_TTY_NAME,
+	.major = 0,
+	.minor = 0,
+	.nr = UART_NR_MAX,
+	.cons = SPRD_CONSOLE,
+};
+
+static int sprd_probe_dt_alias(int index, struct device *dev)
+{
+	struct device_node *np;
+	int ret = index;
+
+	if (!IS_ENABLED(CONFIG_OF))
+		return ret;
+
+	np = dev->of_node;
+	if (!np)
+		return ret;
+
+	ret = of_alias_get_id(np, "serial");
+	if (IS_ERR_VALUE(ret))
+		ret = index;
+	else if (ret >= ARRAY_SIZE(sprd_port) || sprd_port[ret] != NULL) {
+		dev_warn(dev, "requested serial port %d not available.\n", ret);
+		ret = index;
+	}
+
+	return ret;
+}
+
+static int sprd_remove(struct platform_device *dev)
+{
+	struct sprd_uart_port *sup = platform_get_drvdata(dev);
+
+	if (sup) {
+		uart_remove_one_port(&sprd_uart_driver, &sup->port);
+		sprd_port[sup->port.line] = NULL;
+		sprd_ports_num--;
+	}
+
+	if (!sprd_ports_num)
+		uart_unregister_driver(&sprd_uart_driver);
+
+	return 0;
+}
+
+static int sprd_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct uart_port *up;
+	struct clk *clk;
+	int irq;
+	int index;
+	int ret;
+
+	for (index = 0; index < ARRAY_SIZE(sprd_port); index++)
+		if (sprd_port[index] == NULL)
+			break;
+
+	if (index == ARRAY_SIZE(sprd_port))
+		return -EBUSY;
+
+	index = sprd_probe_dt_alias(index, &pdev->dev);
+
+	sprd_port[index] = devm_kzalloc(&pdev->dev,
+		sizeof(*sprd_port[index]), GFP_KERNEL);
+	if (!sprd_port[index])
+		return -ENOMEM;
+
+	up = &sprd_port[index]->port;
+	up->dev = &pdev->dev;
+	up->line = index;
+	up->type = PORT_SPRD;
+	up->iotype = SERIAL_IO_PORT;
+	up->uartclk = SPRD_DEF_RATE;
+	up->fifosize = SPRD_FIFO_SIZE;
+	up->ops = &serial_sprd_ops;
+	up->flags = UPF_BOOT_AUTOCONF;
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (!IS_ERR(clk))
+		up->uartclk = clk_get_rate(clk);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "not provide mem resource\n");
+		return -ENODEV;
+	}
+	up->mapbase = res->start;
+	up->membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(up->membase))
+		return PTR_ERR(up->membase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "not provide irq resource\n");
+		return -ENODEV;
+	}
+	up->irq = irq;
+
+	if (!sprd_ports_num) {
+		ret = uart_register_driver(&sprd_uart_driver);
+		if (ret < 0) {
+			pr_err("Failed to register SPRD-UART driver\n");
+			return ret;
+		}
+	}
+	sprd_ports_num++;
+
+	ret = uart_add_one_port(&sprd_uart_driver, up);
+	if (ret) {
+		sprd_port[index] = NULL;
+		sprd_remove(pdev);
+	}
+
+	platform_set_drvdata(pdev, up);
+
+	return ret;
+}
+
+static int sprd_suspend(struct device *dev)
+{
+	struct sprd_uart_port *sup = dev_get_drvdata(dev);
+
+	uart_suspend_port(&sprd_uart_driver, &sup->port);
+
+	return 0;
+}
+
+static int sprd_resume(struct device *dev)
+{
+	struct sprd_uart_port *sup = dev_get_drvdata(dev);
+
+	uart_resume_port(&sprd_uart_driver, &sup->port);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume);
+
+static const struct of_device_id serial_ids[] = {
+	{.compatible = "sprd,sc9836-uart",},
+	{}
+};
+
+static struct platform_driver sprd_platform_driver = {
+	.probe		= sprd_probe,
+	.remove		= sprd_remove,
+	.driver		= {
+		.name	= "sprd_serial",
+		.of_match_table = of_match_ptr(serial_ids),
+		.pm	= &sprd_pm_ops,
+	},
+};
+
+module_platform_driver(sprd_platform_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");

drivers/tty/serial/xilinx_uartps.c

···
 
 	spin_lock_irqsave(&port->lock, flags);
 
-	/* Empty the receive FIFO 1st before making changes */
-	while ((cdns_uart_readl(CDNS_UART_SR_OFFSET) &
-		 CDNS_UART_SR_RXEMPTY) != CDNS_UART_SR_RXEMPTY) {
-		cdns_uart_readl(CDNS_UART_FIFO_OFFSET);
+	/* Wait for the transmit FIFO to empty before making changes */
+	if (!(cdns_uart_readl(CDNS_UART_CR_OFFSET) & CDNS_UART_CR_TX_DIS)) {
+		while (!(cdns_uart_readl(CDNS_UART_SR_OFFSET) &
+				CDNS_UART_SR_TXEMPTY)) {
+			cpu_relax();
+		}
 	}
 
 	/* Disable the TX and RX to set baud rate */

drivers/tty/tty_buffer.c

···
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tty_buffer_set_limit);
+
+/* slave ptys can claim nested buffer lock when handling BRK and INTR */
+void tty_buffer_set_lock_subclass(struct tty_port *port)
+{
+	lockdep_set_subclass(&port->buf.lock, TTY_LOCK_SLAVE);
+}

drivers/tty/tty_ioctl.c

···
  *	Locking: termios_rwsem
  */
 
-int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
+static int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
 {
 	struct ktermios old_termios;
 	struct tty_ldisc *ld;
···
 	up_write(&tty->termios_rwsem);
 	return 0;
 }
-EXPORT_SYMBOL_GPL(tty_set_termios);
 
 /**
  *	set_termios		-	set termios values for a tty

drivers/tty/tty_mutex.c

···
 #include <linux/semaphore.h>
 #include <linux/sched.h>
 
-/*
- * Nested tty locks are necessary for releasing pty pairs.
- * The stable lock order is master pty first, then slave pty.
- */
-
 /* Legacy tty mutex glue */
-
-enum {
-	TTY_MUTEX_NORMAL,
-	TTY_MUTEX_SLAVE,
-};
 
 /*
  * Getting the big tty mutex.
···
 
 void __lockfunc tty_lock_slave(struct tty_struct *tty)
 {
-	if (tty && tty != tty->link) {
-		WARN_ON(!mutex_is_locked(&tty->link->legacy_mutex) ||
-			!tty->driver->type == TTY_DRIVER_TYPE_PTY ||
-			!tty->driver->type == PTY_TYPE_SLAVE);
+	if (tty && tty != tty->link)
 		tty_lock(tty);
-	}
 }
 
 void __lockfunc tty_unlock_slave(struct tty_struct *tty)
···
 
 void tty_set_lock_subclass(struct tty_struct *tty)
 {
-	lockdep_set_subclass(&tty->legacy_mutex, TTY_MUTEX_SLAVE);
+	lockdep_set_subclass(&tty->legacy_mutex, TTY_LOCK_SLAVE);
 }

drivers/tty/vt/vt.c

···
 #endif
 	if (DO_UPDATE(vc))
 		do_update_region(vc, (unsigned long) p, count);
+	notify_update(vc);
 }
 
 /* used by selection: complement pointer position */
···
 		scr_writew(old, screenpos(vc, old_offset, 1));
 		if (DO_UPDATE(vc))
 			vc->vc_sw->con_putc(vc, old, oldy, oldx);
+		notify_update(vc);
 	}
 
 	old_offset = offset;
···
 			oldy = (offset >> 1) / vc->vc_cols;
 			vc->vc_sw->con_putc(vc, new, oldy, oldx);
 		}
+		notify_update(vc);
 	}
-
 }
 
 static void insert_char(struct vc_data *vc, unsigned int nr)
···
 		if (first == 0 && last == MAX_NR_CONSOLES -1)
 			deflt = 1;
 
-		if (first != -1) {
-			console_lock();
+		if (first != -1)
 			do_bind_con_driver(csw, first, last, deflt);
-			console_unlock();
-		}
 
 		first = -1;
 		last = -1;
···
 			deflt = 1;
 
 		if (first != -1) {
-			console_lock();
 			ret = do_unbind_con_driver(csw, first, last, deflt);
-			console_unlock();
 			if (ret != 0)
 				return ret;
 		}
···
 	struct con_driver *con = dev_get_drvdata(dev);
 	int bind = simple_strtoul(buf, NULL, 0);
 
+	console_lock();
+
 	if (bind)
 		vt_bind(con);
 	else
 		vt_unbind(con);
+
+	console_unlock();
 
 	return count;
 }
···
 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
 		struct con_driver *con_driver = &registered_con_driver[i];
 
-		if (con_driver->con == csw &&
-		    con_driver->flag & CON_DRIVER_FLAG_INIT) {
+		if (con_driver->con == csw) {
 			vtconsole_deinit_device(con_driver);
 			device_destroy(vtconsole_class,
 				       MKDEV(0, con_driver->node));

include/linux/pnp.h

···
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/mod_devicetable.h>
+#include <linux/console.h>
 
 #define PNP_NAME_LEN		50
 
···
 #define PNP_DISABLE		0x0004
 #define PNP_CONFIGURABLE	0x0008
 #define PNP_REMOVABLE		0x0010
+#define PNP_CONSOLE		0x0020
 
 #define pnp_can_read(dev)	(((dev)->protocol->get) && \
 				 ((dev)->capabilities & PNP_READ))
 #define pnp_can_write(dev)	(((dev)->protocol->set) && \
 				 ((dev)->capabilities & PNP_WRITE))
-#define pnp_can_disable(dev)	(((dev)->protocol->disable) && \
-				 ((dev)->capabilities & PNP_DISABLE))
+#define pnp_can_disable(dev)	(((dev)->protocol->disable) &&		  \
+				 ((dev)->capabilities & PNP_DISABLE) &&	  \
+				 (!((dev)->capabilities & PNP_CONSOLE) || \
+				  console_suspend_enabled))
 #define pnp_can_configure(dev)	((!(dev)->active) && \
 				 ((dev)->capabilities & PNP_CONFIGURABLE))
+#define pnp_can_suspend(dev)	(((dev)->protocol->suspend) &&		  \
+				 (!((dev)->capabilities & PNP_CONSOLE) || \
+				  console_suspend_enabled))
+
 
 #ifdef CONFIG_ISAPNP
 extern struct pnp_protocol isapnp_protocol;

include/linux/serial_8250.h

···
 	unsigned char		mcr_force;	/* mask of forced bits */
 	unsigned char		cur_iotype;	/* Running I/O type */
 	unsigned int		rpm_tx_active;
+	unsigned char		canary;		/* non-zero during system sleep
+						 *   if no_console_suspend
+						 */
 
 	/*
 	 * Some bits in registers are cleared on a read, so they must
···
 extern void serial8250_do_shutdown(struct uart_port *port);
 extern void serial8250_do_pm(struct uart_port *port, unsigned int state,
 			     unsigned int oldstate);
+extern void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl);
 extern int fsl8250_handle_irq(struct uart_port *port);
 int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
 unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr);

include/linux/serial_core.h

···
 	void			(*set_termios)(struct uart_port *,
 				               struct ktermios *new,
 				               struct ktermios *old);
+	void			(*set_mctrl)(struct uart_port *, unsigned int);
 	int			(*startup)(struct uart_port *port);
 	void			(*shutdown)(struct uart_port *port);
 	void			(*throttle)(struct uart_port *port);
···
 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
 
-/* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */
-#define UPF_HARD_FLOW		((__force upf_t) (1 << 21))
+/* Port has hardware-assisted h/w flow control */
+#define UPF_AUTO_CTS		((__force upf_t) (1 << 20))
+#define UPF_AUTO_RTS		((__force upf_t) (1 << 21))
+#define UPF_HARD_FLOW		((__force upf_t) (UPF_AUTO_CTS | UPF_AUTO_RTS))
 /* Port has hardware-assisted s/w flow control */
 #define UPF_SOFT_FLOW		((__force upf_t) (1 << 22))
 #define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
···
 #error Change mask not equivalent to userspace-visible bit defines
 #endif
 
-	/* status must be updated while holding port lock */
+	/*
+	 * Must hold termios_rwsem, port mutex and port lock to change;
+	 * can hold any one lock to read.
+	 */
 	upstat_t		status;
 
 #define UPSTAT_CTS_ENABLE	((__force upstat_t) (1 << 0))
 #define UPSTAT_DCD_ENABLE	((__force upstat_t) (1 << 1))
+#define UPSTAT_AUTORTS		((__force upstat_t) (1 << 2))
+#define UPSTAT_AUTOCTS		((__force upstat_t) (1 << 3))
+#define UPSTAT_AUTOXOFF		((__force upstat_t) (1 << 4))
 
 	int			hw_stopped;		/* sw-assisted CTS flow state */
 	unsigned int		mctrl;			/* current modem ctrl settings */
···
 static inline bool uart_cts_enabled(struct uart_port *uport)
 {
 	return !!(uport->status & UPSTAT_CTS_ENABLE);
+}
+
+static inline bool uart_softcts_mode(struct uart_port *uport)
+{
+	upstat_t mask = UPSTAT_CTS_ENABLE | UPSTAT_AUTOCTS;
+
+	return ((uport->status & mask) == UPSTAT_CTS_ENABLE);
 }
 
 /*

include/linux/serial_s3c.h

···
 				   S3C2410_UCON_RXIRQMODE | \
 				   S3C2410_UCON_RXFIFO_TOI)
 
+#define S3C64XX_UCON_TXBURST_1          (0<<20)
+#define S3C64XX_UCON_TXBURST_4          (1<<20)
+#define S3C64XX_UCON_TXBURST_8          (2<<20)
+#define S3C64XX_UCON_TXBURST_16         (3<<20)
+#define S3C64XX_UCON_TXBURST_MASK       (0xf<<20)
+#define S3C64XX_UCON_RXBURST_1          (0<<16)
+#define S3C64XX_UCON_RXBURST_4          (1<<16)
+#define S3C64XX_UCON_RXBURST_8          (2<<16)
+#define S3C64XX_UCON_RXBURST_16         (3<<16)
+#define S3C64XX_UCON_RXBURST_MASK       (0xf<<16)
+#define S3C64XX_UCON_TIMEOUT_SHIFT      (12)
+#define S3C64XX_UCON_TIMEOUT_MASK       (0xf<<12)
+#define S3C64XX_UCON_EMPTYINT_EN        (1<<11)
+#define S3C64XX_UCON_DMASUS_EN          (1<<10)
+#define S3C64XX_UCON_TXINT_LEVEL        (1<<9)
+#define S3C64XX_UCON_RXINT_LEVEL        (1<<8)
+#define S3C64XX_UCON_TIMEOUT_EN         (1<<7)
+#define S3C64XX_UCON_ERRINT_EN          (1<<6)
+#define S3C64XX_UCON_TXMODE_DMA         (2<<2)
+#define S3C64XX_UCON_TXMODE_CPU         (1<<2)
+#define S3C64XX_UCON_TXMODE_MASK        (3<<2)
+#define S3C64XX_UCON_RXMODE_DMA         (2<<0)
+#define S3C64XX_UCON_RXMODE_CPU         (1<<0)
+#define S3C64XX_UCON_RXMODE_MASK        (3<<0)
+
 #define S3C2410_UFCON_FIFOMODE	  (1<<0)
 #define S3C2410_UFCON_TXTRIG0	  (0<<6)
 #define S3C2410_UFCON_RXTRIG8	  (1<<4)
···
 #define S3C2440_UFSTAT_TXMASK	  (63<<8)
 #define S3C2440_UFSTAT_RXMASK	  (63)
 
+#define S3C2410_UTRSTAT_TIMEOUT   (1<<3)
 #define S3C2410_UTRSTAT_TXE	  (1<<2)
 #define S3C2410_UTRSTAT_TXFE	  (1<<1)
 #define S3C2410_UTRSTAT_RXDR	  (1<<0)
···
 #define S3C64XX_UINTM		0x38
 
 #define S3C64XX_UINTM_RXD	(0)
+#define S3C64XX_UINTM_ERROR     (1)
 #define S3C64XX_UINTM_TXD	(2)
 #define S3C64XX_UINTM_RXD_MSK	(1 << S3C64XX_UINTM_RXD)
+#define S3C64XX_UINTM_ERR_MSK   (1 << S3C64XX_UINTM_ERROR)
 #define S3C64XX_UINTM_TXD_MSK	(1 << S3C64XX_UINTM_TXD)
 
 /* Following are specific to S5PV210 */

include/linux/tty.h

···
 #include <linux/llist.h>
 
 
+/*
+ * Lock subclasses for tty locks
+ *
+ * TTY_LOCK_NORMAL is for normal ttys and master ptys.
+ * TTY_LOCK_SLAVE is for slave ptys only.
+ *
+ * Lock subclasses are necessary for handling nested locking with pty pairs.
+ * tty locks which use nested locking:
+ *
+ * legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
+ *		  The stable lock order is master pty first, then slave pty.
+ * termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
+ *		   Subclassing this lock enables the slave pty to hold its
+ *		   termios_rwsem when claiming the master tty_buffer lock.
+ * tty_buffer lock - slave ptys can claim nested buffer lock when handling
+ *		     signal chars. The stable lock order is slave pty, then
+ *		     master.
+ */
+
+enum {
+	TTY_LOCK_NORMAL = 0,
+	TTY_LOCK_SLAVE,
+};
 
 /*
  * (Note: the *_driver.minor_start values 1, 64, 128, 192 are
···
 extern void tty_buffer_free_all(struct tty_port *port);
 extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
 extern void tty_buffer_init(struct tty_port *port);
+extern void tty_buffer_set_lock_subclass(struct tty_port *port);
 extern speed_t tty_termios_baud_rate(struct ktermios *termios);
 extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
 extern void tty_termios_encode_baud_rate(struct ktermios *termios,
···
 
 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
 extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
-extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 
 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
 extern void tty_ldisc_deref(struct tty_ldisc *);

include/linux/vt_buffer.h

···
 #ifndef VT_BUF_HAVE_RW
 #define scr_writew(val, addr) (*(addr) = (val))
 #define scr_readw(addr) (*(addr))
-#define scr_memcpyw(d, s, c) memcpy(d, s, c)
-#define scr_memmovew(d, s, c) memmove(d, s, c)
-#define VT_BUF_HAVE_MEMCPYW
-#define VT_BUF_HAVE_MEMMOVEW
 #endif
 
 #ifndef VT_BUF_HAVE_MEMSETW

include/uapi/linux/serial_core.h

···
 #define PORT_ALTR_16550_F64 27	/* Altera 16550 UART with 64 FIFOs */
 #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */
 #define PORT_RT2880	29	/* Ralink RT2880 internal UART */
-#define PORT_MAX_8250	29	/* max port ID */
+#define PORT_16550A_FSL64 30	/* Freescale 16550 UART with 64 FIFOs */
+#define PORT_MAX_8250	30	/* max port ID */
 
 /*
  * ARM specific type numbers.  These are not currently guaranteed
···
 
 /* MESON */
 #define PORT_MESON	109
+
+/* Conexant Digicolor */
+#define PORT_DIGICOLOR	110
+
+/* SPRD SERIAL  */
+#define PORT_SPRD	111
+
+/* Cris v10 / v32 SoC */
+#define PORT_CRIS	112
 
 #endif /* _UAPILINUX_SERIAL_CORE_H */

include/uapi/linux/serial_reg.h

···
 #define UART_FCR6_T_TRIGGER_8	0x10 /* Mask for transmit trigger set at 8 */
 #define UART_FCR6_T_TRIGGER_24  0x20 /* Mask for transmit trigger set at 24 */
 #define UART_FCR6_T_TRIGGER_30	0x30 /* Mask for transmit trigger set at 30 */
-#define UART_FCR7_64BYTE	0x20 /* Go into 64 byte mode (TI16C750) */
+#define UART_FCR7_64BYTE	0x20 /* Go into 64 byte mode (TI16C750 and
+					some Freescale UARTs) */
 
 #define UART_FCR_R_TRIG_SHIFT		6
 #define UART_FCR_R_TRIG_BITS(x)		\