serial: 8250: Split base port operations from universal driver

Refactor base port operations into new file; 8250_port.c.

Legacy irq handling, RSA port support, port storage for universal
driver, driver definition, module parameters and linkage remain in
8250_core.c

The source file split and resulting modules is diagrammed below:

8250_core.c ====> 8250_core.c __
\ \
\ +-- 8250.ko (alias 8250_core)
\ 8250_pnp.c __/ (universal driver)
\
=> 8250_port.c __
\
+-- 8250_base.ko
8250_dma.c __/ (port operations)

Signed-off-by: Peter Hurley <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/8250/8250.h

···
 	}
 	return 1;
 }
+
+static inline int serial_index(struct uart_port *port)
+{
+	return port->minor - 64;
+}
+
+#if 0
+#define DEBUG_INTR(fmt...)	printk(fmt)
+#else
+#define DEBUG_INTR(fmt...)	do { } while (0)
+#endif

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

···
 /*
- *  Driver for 8250/16550-type serial ports
+ *  Universal/legacy driver for 8250/16550-type serial ports
  *
  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
  *
  *  Copyright (C) 2001 Russell King.
  *
+ *  Supports: ISA-compatible 8250/16550 ports
+ *	      PNP 8250/16550 ports
+ *	      early_serial_setup() ports
+ *	      userspace-configurable "phantom" ports
+ *	      "serial8250" platform devices
+ *	      serial8250_register_8250_port() ports
+ *
  * 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.
- *
- * A note about mapbase / membase
- *
- *  mapbase is the physical address of the IO port.
- *  membase is an 'ioremapped' cookie.
  */
-
-#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
 
 #include <linux/module.h>
 #include <linux/moduleparam.h>
···
 
 static struct uart_driver serial8250_reg;
 
-static int serial_index(struct uart_port *port)
-{
-	return port->minor - 64;
-}
-
 static unsigned int skip_txen_test; /* force skip of txen test at init time */
 
-/*
- * Debugging.
- */
-#if 0
-#define DEBUG_AUTOCONF(fmt...)	printk(fmt)
-#else
-#define DEBUG_AUTOCONF(fmt...)	do { } while (0)
-#endif
-
-#if 0
-#define DEBUG_INTR(fmt...)	printk(fmt)
-#else
-#define DEBUG_INTR(fmt...)	do { } while (0)
-#endif
-
 #define PASS_LIMIT	512
-
-#define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)
-
 
 #include <asm/serial.h>
 /*
···
 #define NR_IRQ_HASH		32	/* Can be adjusted later */
 static struct hlist_head irq_lists[NR_IRQ_HASH];
 static DEFINE_MUTEX(hash_mutex);	/* Used to walk the hash */
-
-/*
- * Here we define the default xmit fifo size used for each type of UART.
- */
-static const struct serial8250_config uart_config[] = {
-	[PORT_UNKNOWN] = {
-		.name		= "unknown",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-	},
-	[PORT_8250] = {
-		.name		= "8250",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-	},
-	[PORT_16450] = {
-		.name		= "16450",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-	},
-	[PORT_16550] = {
-		.name		= "16550",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-	},
-	[PORT_16550A] = {
-		.name		= "16550A",
-		.fifo_size	= 16,
-		.tx_loadsz	= 16,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.rxtrig_bytes	= {1, 4, 8, 14},
-		.flags		= UART_CAP_FIFO,
-	},
-	[PORT_CIRRUS] = {
-		.name		= "Cirrus",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-	},
-	[PORT_16650] = {
-		.name		= "ST16650",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
-	},
-	[PORT_16650V2] = {
-		.name		= "ST16650V2",
-		.fifo_size	= 32,
-		.tx_loadsz	= 16,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
-				  UART_FCR_T_TRIG_00,
-		.rxtrig_bytes	= {8, 16, 24, 28},
-		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
-	},
-	[PORT_16750] = {
-		.name		= "TI16750",
-		.fifo_size	= 64,
-		.tx_loadsz	= 64,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
-				  UART_FCR7_64BYTE,
-		.rxtrig_bytes	= {1, 16, 32, 56},
-		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
-	},
-	[PORT_STARTECH] = {
-		.name		= "Startech",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1,
-	},
-	[PORT_16C950] = {
-		.name		= "16C950/954",
-		.fifo_size	= 128,
-		.tx_loadsz	= 128,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		/* UART_CAP_EFR breaks billionon CF bluetooth card. */
-		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
-	},
-	[PORT_16654] = {
-		.name		= "ST16654",
-		.fifo_size	= 64,
-		.tx_loadsz	= 32,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
-				  UART_FCR_T_TRIG_10,
-		.rxtrig_bytes	= {8, 16, 56, 60},
-		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
-	},
-	[PORT_16850] = {
-		.name		= "XR16850",
-		.fifo_size	= 128,
-		.tx_loadsz	= 128,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
-	},
-	[PORT_RSA] = {
-		.name		= "RSA",
-		.fifo_size	= 2048,
-		.tx_loadsz	= 2048,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
-		.flags		= UART_CAP_FIFO,
-	},
-	[PORT_NS16550A] = {
-		.name		= "NS16550A",
-		.fifo_size	= 16,
-		.tx_loadsz	= 16,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_NATSEMI,
-	},
-	[PORT_XSCALE] = {
-		.name		= "XScale",
-		.fifo_size	= 32,
-		.tx_loadsz	= 32,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
-	},
-	[PORT_OCTEON] = {
-		.name		= "OCTEON",
-		.fifo_size	= 64,
-		.tx_loadsz	= 64,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO,
-	},
-	[PORT_AR7] = {
-		.name		= "AR7",
-		.fifo_size	= 16,
-		.tx_loadsz	= 16,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
-	},
-	[PORT_U6_16550A] = {
-		.name		= "U6_16550A",
-		.fifo_size	= 64,
-		.tx_loadsz	= 64,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
-	},
-	[PORT_TEGRA] = {
-		.name		= "Tegra",
-		.fifo_size	= 32,
-		.tx_loadsz	= 8,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
-				  UART_FCR_T_TRIG_01,
-		.rxtrig_bytes	= {1, 4, 8, 14},
-		.flags		= UART_CAP_FIFO | UART_CAP_RTOIE,
-	},
-	[PORT_XR17D15X] = {
-		.name		= "XR17D15X",
-		.fifo_size	= 64,
-		.tx_loadsz	= 64,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
-				  UART_CAP_SLEEP,
-	},
-	[PORT_XR17V35X] = {
-		.name		= "XR17V35X",
-		.fifo_size	= 256,
-		.tx_loadsz	= 256,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 |
-				  UART_FCR_T_TRIG_11,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
-				  UART_CAP_SLEEP,
-	},
-	[PORT_LPC3220] = {
-		.name		= "LPC3220",
-		.fifo_size	= 64,
-		.tx_loadsz	= 32,
-		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
-				  UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00,
-		.flags		= UART_CAP_FIFO,
-	},
-	[PORT_BRCM_TRUMANAGE] = {
-		.name		= "TruManage",
-		.fifo_size	= 1,
-		.tx_loadsz	= 1024,
-		.flags		= UART_CAP_HFIFO,
-	},
-	[PORT_8250_CIR] = {
-		.name		= "CIR port"
-	},
-	[PORT_ALTR_16550_F32] = {
-		.name		= "Altera 16550 FIFO32",
-		.fifo_size	= 32,
-		.tx_loadsz	= 32,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
-	},
-	[PORT_ALTR_16550_F64] = {
-		.name		= "Altera 16550 FIFO64",
-		.fifo_size	= 64,
-		.tx_loadsz	= 64,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
-	},
-	[PORT_ALTR_16550_F128] = {
-		.name		= "Altera 16550 FIFO128",
-		.fifo_size	= 128,
-		.tx_loadsz	= 128,
-		.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 */
-static int default_serial_dl_read(struct uart_8250_port *up)
-{
-	return serial_in(up, UART_DLL) | serial_in(up, UART_DLM) << 8;
-}
-
-/* Uart divisor latch write */
-static void default_serial_dl_write(struct uart_8250_port *up, int value)
-{
-	serial_out(up, UART_DLL, value & 0xff);
-	serial_out(up, UART_DLM, value >> 8 & 0xff);
-}
-
-#if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
-
-/* Au1x00/RT288x UART hardware has a weird register layout */
-static const s8 au_io_in_map[8] = {
-	 0,	/* UART_RX  */
-	 2,	/* UART_IER */
-	 3,	/* UART_IIR */
-	 5,	/* UART_LCR */
-	 6,	/* UART_MCR */
-	 7,	/* UART_LSR */
-	 8,	/* UART_MSR */
-	-1,	/* UART_SCR (unmapped) */
-};
-
-static const s8 au_io_out_map[8] = {
-	 1,	/* UART_TX  */
-	 2,	/* UART_IER */
-	 4,	/* UART_FCR */
-	 5,	/* UART_LCR */
-	 6,	/* UART_MCR */
-	-1,	/* UART_LSR (unmapped) */
-	-1,	/* UART_MSR (unmapped) */
-	-1,	/* UART_SCR (unmapped) */
-};
-
-static unsigned int au_serial_in(struct uart_port *p, int offset)
-{
-	if (offset >= ARRAY_SIZE(au_io_in_map))
-		return UINT_MAX;
-	offset = au_io_in_map[offset];
-	if (offset < 0)
-		return UINT_MAX;
-	return __raw_readl(p->membase + (offset << p->regshift));
-}
-
-static void au_serial_out(struct uart_port *p, int offset, int value)
-{
-	if (offset >= ARRAY_SIZE(au_io_out_map))
-		return;
-	offset = au_io_out_map[offset];
-	if (offset < 0)
-		return;
-	__raw_writel(value, p->membase + (offset << p->regshift));
-}
-
-/* Au1x00 haven't got a standard divisor latch */
-static int au_serial_dl_read(struct uart_8250_port *up)
-{
-	return __raw_readl(up->port.membase + 0x28);
-}
-
-static void au_serial_dl_write(struct uart_8250_port *up, int value)
-{
-	__raw_writel(value, up->port.membase + 0x28);
-}
-
-#endif
-
-static unsigned int hub6_serial_in(struct uart_port *p, int offset)
-{
-	offset = offset << p->regshift;
-	outb(p->hub6 - 1 + offset, p->iobase);
-	return inb(p->iobase + 1);
-}
-
-static void hub6_serial_out(struct uart_port *p, int offset, int value)
-{
-	offset = offset << p->regshift;
-	outb(p->hub6 - 1 + offset, p->iobase);
-	outb(value, p->iobase + 1);
-}
-
-static unsigned int mem_serial_in(struct uart_port *p, int offset)
-{
-	offset = offset << p->regshift;
-	return readb(p->membase + offset);
-}
-
-static void mem_serial_out(struct uart_port *p, int offset, int value)
-{
-	offset = offset << p->regshift;
-	writeb(value, p->membase + offset);
-}
-
-static void mem32_serial_out(struct uart_port *p, int offset, int value)
-{
-	offset = offset << p->regshift;
-	writel(value, p->membase + offset);
-}
-
-static unsigned int mem32_serial_in(struct uart_port *p, int offset)
-{
-	offset = offset << p->regshift;
-	return readl(p->membase + offset);
-}
-
-static void mem32be_serial_out(struct uart_port *p, int offset, int value)
-{
-	offset = offset << p->regshift;
-	iowrite32be(value, p->membase + offset);
-}
-
-static unsigned int mem32be_serial_in(struct uart_port *p, int offset)
-{
-	offset = offset << p->regshift;
-	return ioread32be(p->membase + offset);
-}
-
-static unsigned int io_serial_in(struct uart_port *p, int offset)
-{
-	offset = offset << p->regshift;
-	return inb(p->iobase + offset);
-}
-
-static void io_serial_out(struct uart_port *p, int offset, int value)
-{
-	offset = offset << p->regshift;
-	outb(value, p->iobase + offset);
-}
-
-static int serial8250_default_handle_irq(struct uart_port *port);
-static int exar_handle_irq(struct uart_port *port);
-
-static void set_io_from_upio(struct uart_port *p)
-{
-	struct uart_8250_port *up = up_to_u8250p(p);
-
-	up->dl_read = default_serial_dl_read;
-	up->dl_write = default_serial_dl_write;
-
-	switch (p->iotype) {
-	case UPIO_HUB6:
-		p->serial_in = hub6_serial_in;
-		p->serial_out = hub6_serial_out;
-		break;
-
-	case UPIO_MEM:
-		p->serial_in = mem_serial_in;
-		p->serial_out = mem_serial_out;
-		break;
-
-	case UPIO_MEM32:
-		p->serial_in = mem32_serial_in;
-		p->serial_out = mem32_serial_out;
-		break;
-
-	case UPIO_MEM32BE:
-		p->serial_in = mem32be_serial_in;
-		p->serial_out = mem32be_serial_out;
-		break;
-
-#if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
-	case UPIO_AU:
-		p->serial_in = au_serial_in;
-		p->serial_out = au_serial_out;
-		up->dl_read = au_serial_dl_read;
-		up->dl_write = au_serial_dl_write;
-		break;
-#endif
-
-	default:
-		p->serial_in = io_serial_in;
-		p->serial_out = io_serial_out;
-		break;
-	}
-	/* Remember loaded iotype */
-	up->cur_iotype = p->iotype;
-	p->handle_irq = serial8250_default_handle_irq;
-}
-
-static void
-serial_port_out_sync(struct uart_port *p, int offset, int value)
-{
-	switch (p->iotype) {
-	case UPIO_MEM:
-	case UPIO_MEM32:
-	case UPIO_MEM32BE:
-	case UPIO_AU:
-		p->serial_out(p, offset, value);
-		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
-		break;
-	default:
-		p->serial_out(p, offset, value);
-	}
-}
-
-/*
- * For the 16C950
- */
-static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
-{
-	serial_out(up, UART_SCR, offset);
-	serial_out(up, UART_ICR, value);
-}
-
-static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
-{
-	unsigned int value;
-
-	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
-	serial_out(up, UART_SCR, offset);
-	value = serial_in(up, UART_ICR);
-	serial_icr_write(up, UART_ACR, up->acr);
-
-	return value;
-}
-
-/*
- * FIFO support.
- */
-static void serial8250_clear_fifos(struct uart_8250_port *p)
-{
-	if (p->capabilities & UART_CAP_FIFO) {
-		serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO);
-		serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO |
-			       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
-		serial_out(p, UART_FCR, 0);
-	}
-}
-
-void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
-{
-	serial8250_clear_fifos(p);
-	serial_out(p, UART_FCR, p->fcr);
-}
-EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
-
-void serial8250_rpm_get(struct uart_8250_port *p)
-{
-	if (!(p->capabilities & UART_CAP_RPM))
-		return;
-	pm_runtime_get_sync(p->port.dev);
-}
-EXPORT_SYMBOL_GPL(serial8250_rpm_get);
-
-void serial8250_rpm_put(struct uart_8250_port *p)
-{
-	if (!(p->capabilities & UART_CAP_RPM))
-		return;
-	pm_runtime_mark_last_busy(p->port.dev);
-	pm_runtime_put_autosuspend(p->port.dev);
-}
-EXPORT_SYMBOL_GPL(serial8250_rpm_put);
-
-/*
- * These two wrappers ensure that enable_runtime_pm_tx() can be called more than
- * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
- * empty and the HW can idle again.
- */
-static void serial8250_rpm_get_tx(struct uart_8250_port *p)
-{
-	unsigned char rpm_active;
-
-	if (!(p->capabilities & UART_CAP_RPM))
-		return;
-
-	rpm_active = xchg(&p->rpm_tx_active, 1);
-	if (rpm_active)
-		return;
-	pm_runtime_get_sync(p->port.dev);
-}
-
-static void serial8250_rpm_put_tx(struct uart_8250_port *p)
-{
-	unsigned char rpm_active;
-
-	if (!(p->capabilities & UART_CAP_RPM))
-		return;
-
-	rpm_active = xchg(&p->rpm_tx_active, 0);
-	if (!rpm_active)
-		return;
-	pm_runtime_mark_last_busy(p->port.dev);
-	pm_runtime_put_autosuspend(p->port.dev);
-}
-
-/*
- * IER sleep support.  UARTs which have EFRs need the "extended
- * capability" bit enabled.  Note that on XR16C850s, we need to
- * reset LCR to write to IER.
- */
-static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
-{
-	unsigned char lcr = 0, efr = 0;
-	/*
-	 * Exar UARTs have a SLEEP register that enables or disables
-	 * each UART to enter sleep mode separately.  On the XR17V35x the
-	 * register is accessible to each UART at the UART_EXAR_SLEEP
-	 * offset but the UART channel may only write to the corresponding
-	 * bit.
-	 */
-	serial8250_rpm_get(p);
-	if ((p->port.type == PORT_XR17V35X) ||
-	   (p->port.type == PORT_XR17D15X)) {
-		serial_out(p, UART_EXAR_SLEEP, sleep ? 0xff : 0);
-		goto out;
-	}
-
-	if (p->capabilities & UART_CAP_SLEEP) {
-		if (p->capabilities & UART_CAP_EFR) {
-			lcr = serial_in(p, UART_LCR);
-			efr = serial_in(p, UART_EFR);
-			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
-			serial_out(p, UART_EFR, UART_EFR_ECB);
-			serial_out(p, UART_LCR, 0);
-		}
-		serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
-		if (p->capabilities & UART_CAP_EFR) {
-			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
-			serial_out(p, UART_EFR, efr);
-			serial_out(p, UART_LCR, lcr);
-		}
-	}
-out:
-	serial8250_rpm_put(p);
-}
-
-#ifdef CONFIG_SERIAL_8250_RSA
-/*
- * Attempts to turn on the RSA FIFO.  Returns zero on failure.
- * We set the port uart clock rate if we succeed.
- */
-static int __enable_rsa(struct uart_8250_port *up)
-{
-	unsigned char mode;
-	int result;
-
-	mode = serial_in(up, UART_RSA_MSR);
-	result = mode & UART_RSA_MSR_FIFO;
-
-	if (!result) {
-		serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
-		mode = serial_in(up, UART_RSA_MSR);
-		result = mode & UART_RSA_MSR_FIFO;
-	}
-
-	if (result)
-		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
-
-	return result;
-}
-
-static void enable_rsa(struct uart_8250_port *up)
-{
-	if (up->port.type == PORT_RSA) {
-		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
-			spin_lock_irq(&up->port.lock);
-			__enable_rsa(up);
-			spin_unlock_irq(&up->port.lock);
-		}
-		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
-			serial_out(up, UART_RSA_FRR, 0);
-	}
-}
-
-/*
- * Attempts to turn off the RSA FIFO.  Returns zero on failure.
- * It is unknown why interrupts were disabled in here.  However,
- * the caller is expected to preserve this behaviour by grabbing
- * the spinlock before calling this function.
- */
-static void disable_rsa(struct uart_8250_port *up)
-{
-	unsigned char mode;
-	int result;
-
-	if (up->port.type == PORT_RSA &&
-	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
-		spin_lock_irq(&up->port.lock);
-
-		mode = serial_in(up, UART_RSA_MSR);
-		result = !(mode & UART_RSA_MSR_FIFO);
-
-		if (!result) {
-			serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
-			mode = serial_in(up, UART_RSA_MSR);
-			result = !(mode & UART_RSA_MSR_FIFO);
-		}
-
-		if (result)
-			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
-		spin_unlock_irq(&up->port.lock);
-	}
-}
-#endif /* CONFIG_SERIAL_8250_RSA */
-
-/*
- * This is a quickie test to see how big the FIFO is.
- * It doesn't work at all the time, more's the pity.
- */
-static int size_fifo(struct uart_8250_port *up)
-{
-	unsigned char old_fcr, old_mcr, old_lcr;
-	unsigned short old_dl;
-	int count;
-
-	old_lcr = serial_in(up, UART_LCR);
-	serial_out(up, UART_LCR, 0);
-	old_fcr = serial_in(up, UART_FCR);
-	old_mcr = serial_in(up, UART_MCR);
-	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
-		    UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
-	serial_out(up, UART_MCR, UART_MCR_LOOP);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-	old_dl = serial_dl_read(up);
-	serial_dl_write(up, 0x0001);
-	serial_out(up, UART_LCR, 0x03);
-	for (count = 0; count < 256; count++)
-		serial_out(up, UART_TX, count);
-	mdelay(20);/* FIXME - schedule_timeout */
-	for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) &&
-	     (count < 256); count++)
-		serial_in(up, UART_RX);
-	serial_out(up, UART_FCR, old_fcr);
-	serial_out(up, UART_MCR, old_mcr);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-	serial_dl_write(up, old_dl);
-	serial_out(up, UART_LCR, old_lcr);
-
-	return count;
-}
-
-/*
- * Read UART ID using the divisor method - set DLL and DLM to zero
- * and the revision will be in DLL and device type in DLM.  We
- * preserve the device state across this.
- */
-static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
-{
-	unsigned char old_dll, old_dlm, old_lcr;
-	unsigned int id;
-
-	old_lcr = serial_in(p, UART_LCR);
-	serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A);
-
-	old_dll = serial_in(p, UART_DLL);
-	old_dlm = serial_in(p, UART_DLM);
-
-	serial_out(p, UART_DLL, 0);
-	serial_out(p, UART_DLM, 0);
-
-	id = serial_in(p, UART_DLL) | serial_in(p, UART_DLM) << 8;
-
-	serial_out(p, UART_DLL, old_dll);
-	serial_out(p, UART_DLM, old_dlm);
-	serial_out(p, UART_LCR, old_lcr);
-
-	return id;
-}
-
-/*
- * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
- * When this function is called we know it is at least a StarTech
- * 16650 V2, but it might be one of several StarTech UARTs, or one of
- * its clones.  (We treat the broken original StarTech 16650 V1 as a
- * 16550, and why not?  Startech doesn't seem to even acknowledge its
- * existence.)
- *
- * What evil have men's minds wrought...
- */
-static void autoconfig_has_efr(struct uart_8250_port *up)
-{
-	unsigned int id1, id2, id3, rev;
-
-	/*
-	 * Everything with an EFR has SLEEP
-	 */
-	up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
-
-	/*
-	 * First we check to see if it's an Oxford Semiconductor UART.
-	 *
-	 * If we have to do this here because some non-National
-	 * Semiconductor clone chips lock up if you try writing to the
-	 * LSR register (which serial_icr_read does)
-	 */
-
-	/*
-	 * Check for Oxford Semiconductor 16C950.
-	 *
-	 * EFR [4] must be set else this test fails.
-	 *
-	 * This shouldn't be necessary, but Mike Hudson ([e-mail])
-	 * claims that it's needed for 952 dual UART's (which are not
-	 * recommended for new designs).
-	 */
-	up->acr = 0;
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, UART_EFR_ECB);
-	serial_out(up, UART_LCR, 0x00);
-	id1 = serial_icr_read(up, UART_ID1);
-	id2 = serial_icr_read(up, UART_ID2);
-	id3 = serial_icr_read(up, UART_ID3);
-	rev = serial_icr_read(up, UART_REV);
-
-	DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
-
-	if (id1 == 0x16 && id2 == 0xC9 &&
-	    (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
-		up->port.type = PORT_16C950;
-
-		/*
-		 * Enable work around for the Oxford Semiconductor 952 rev B
-		 * chip which causes it to seriously miscalculate baud rates
-		 * when DLL is 0.
-		 */
-		if (id3 == 0x52 && rev == 0x01)
-			up->bugs |= UART_BUG_QUOT;
-		return;
-	}
-
-	/*
-	 * We check for a XR16C850 by setting DLL and DLM to 0, and then
-	 * reading back DLL and DLM.  The chip type depends on the DLM
-	 * value read back:
-	 *  0x10 - XR16C850 and the DLL contains the chip revision.
-	 *  0x12 - XR16C2850.
-	 *  0x14 - XR16C854.
-	 */
-	id1 = autoconfig_read_divisor_id(up);
-	DEBUG_AUTOCONF("850id=%04x ", id1);
-
-	id2 = id1 >> 8;
-	if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
-		up->port.type = PORT_16850;
-		return;
-	}
-
-	/*
-	 * It wasn't an XR16C850.
-	 *
-	 * We distinguish between the '654 and the '650 by counting
-	 * how many bytes are in the FIFO.  I'm using this for now,
-	 * since that's the technique that was sent to me in the
-	 * serial driver update, but I'm not convinced this works.
-	 * I've had problems doing this in the past.  -TYT
-	 */
-	if (size_fifo(up) == 64)
-		up->port.type = PORT_16654;
-	else
-		up->port.type = PORT_16650V2;
-}
-
-/*
- * We detected a chip without a FIFO.  Only two fall into
- * this category - the original 8250 and the 16450.  The
- * 16450 has a scratch register (accessible with LCR=0)
- */
-static void autoconfig_8250(struct uart_8250_port *up)
-{
-	unsigned char scratch, status1, status2;
-
-	up->port.type = PORT_8250;
-
-	scratch = serial_in(up, UART_SCR);
-	serial_out(up, UART_SCR, 0xa5);
-	status1 = serial_in(up, UART_SCR);
-	serial_out(up, UART_SCR, 0x5a);
-	status2 = serial_in(up, UART_SCR);
-	serial_out(up, UART_SCR, scratch);
-
-	if (status1 == 0xa5 && status2 == 0x5a)
-		up->port.type = PORT_16450;
-}
-
-static int broken_efr(struct uart_8250_port *up)
-{
-	/*
-	 * Exar ST16C2550 "A2" devices incorrectly detect as
-	 * having an EFR, and report an ID of 0x0201.  See
-	 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html
-	 */
-	if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
-		return 1;
-
-	return 0;
-}
-
-/*
- * We know that the chip has FIFOs.  Does it have an EFR?  The
- * EFR is located in the same register position as the IIR and
- * we know the top two bits of the IIR are currently set.  The
- * EFR should contain zero.  Try to read the EFR.
- */
-static void autoconfig_16550a(struct uart_8250_port *up)
-{
-	unsigned char status1, status2;
-	unsigned int iersave;
-
-	up->port.type = PORT_16550A;
-	up->capabilities |= UART_CAP_FIFO;
-
-	/*
-	 * XR17V35x UARTs have an extra divisor register, DLD
-	 * that gets enabled with when DLAB is set which will
-	 * cause the device to incorrectly match and assign
-	 * port type to PORT_16650.  The EFR for this UART is
-	 * found at offset 0x09. Instead check the Deice ID (DVID)
-	 * register for a 2, 4 or 8 port UART.
-	 */
-	if (up->port.flags & UPF_EXAR_EFR) {
-		status1 = serial_in(up, UART_EXAR_DVID);
-		if (status1 == 0x82 || status1 == 0x84 || status1 == 0x88) {
-			DEBUG_AUTOCONF("Exar XR17V35x ");
-			up->port.type = PORT_XR17V35X;
-			up->capabilities |= UART_CAP_AFE | UART_CAP_EFR |
-						UART_CAP_SLEEP;
-
-			return;
-		}
-
-	}
-
-	/*
-	 * Check for presence of the EFR when DLAB is set.
-	 * Only ST16C650V1 UARTs pass this test.
-	 */
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-	if (serial_in(up, UART_EFR) == 0) {
-		serial_out(up, UART_EFR, 0xA8);
-		if (serial_in(up, UART_EFR) != 0) {
-			DEBUG_AUTOCONF("EFRv1 ");
-			up->port.type = PORT_16650;
-			up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
-		} else {
-			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;
-	}
-
-	/*
-	 * Maybe it requires 0xbf to be written to the LCR.
-	 * (other ST16C650V2 UARTs, TI16C752A, etc)
-	 */
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
-		DEBUG_AUTOCONF("EFRv2 ");
-		autoconfig_has_efr(up);
-		return;
-	}
-
-	/*
-	 * Check for a National Semiconductor SuperIO chip.
-	 * Attempt to switch to bank 2, read the value of the LOOP bit
-	 * from EXCR1. Switch back to bank 0, change it in MCR. Then
-	 * switch back to bank 2, read it from EXCR1 again and check
-	 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
-	 */
-	serial_out(up, UART_LCR, 0);
-	status1 = serial_in(up, UART_MCR);
-	serial_out(up, UART_LCR, 0xE0);
-	status2 = serial_in(up, 0x02); /* EXCR1 */
-
-	if (!((status2 ^ status1) & UART_MCR_LOOP)) {
-		serial_out(up, UART_LCR, 0);
-		serial_out(up, UART_MCR, status1 ^ UART_MCR_LOOP);
-		serial_out(up, UART_LCR, 0xE0);
-		status2 = serial_in(up, 0x02); /* EXCR1 */
-		serial_out(up, UART_LCR, 0);
-		serial_out(up, UART_MCR, status1);
-
-		if ((status2 ^ status1) & UART_MCR_LOOP) {
-			unsigned short quot;
-
-			serial_out(up, UART_LCR, 0xE0);
-
-			quot = serial_dl_read(up);
-			quot <<= 3;
-
-			if (ns16550a_goto_highspeed(up))
-				serial_dl_write(up, quot);
-
-			serial_out(up, UART_LCR, 0);
-
-			up->port.uartclk = 921600*16;
-			up->port.type = PORT_NS16550A;
-			up->capabilities |= UART_NATSEMI;
-			return;
-		}
-	}
-
-	/*
-	 * No EFR.  Try to detect a TI16750, which only sets bit 5 of
-	 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
-	 * Try setting it with and without DLAB set.  Cheap clones
-	 * set bit 5 without DLAB set.
-	 */
-	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, UART_FCR_ENABLE_FIFO);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
-	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
-	status2 = serial_in(up, UART_IIR) >> 5;
-	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
-	serial_out(up, UART_LCR, 0);
-
-	DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
-
-	if (status1 == 6 && status2 == 7) {
-		up->port.type = PORT_16750;
-		up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
-		return;
-	}
-
-	/*
-	 * Try writing and reading the UART_IER_UUE bit (b6).
-	 * If it works, this is probably one of the Xscale platform's
-	 * internal UARTs.
-	 * We're going to explicitly set the UUE bit to 0 before
-	 * trying to write and read a 1 just to make sure it's not
-	 * already a 1 and maybe locked there before we even start start.
-	 */
-	iersave = serial_in(up, UART_IER);
-	serial_out(up, UART_IER, iersave & ~UART_IER_UUE);
-	if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
-		/*
-		 * OK it's in a known zero state, try writing and reading
-		 * without disturbing the current state of the other bits.
-		 */
-		serial_out(up, UART_IER, iersave | UART_IER_UUE);
-		if (serial_in(up, UART_IER) & UART_IER_UUE) {
-			/*
-			 * It's an Xscale.
-			 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
-			 */
-			DEBUG_AUTOCONF("Xscale ");
-			up->port.type = PORT_XSCALE;
-			up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
-			return;
-		}
-	} else {
-		/*
-		 * If we got here we couldn't force the IER_UUE bit to 0.
-		 * Log it and continue.
-		 */
-		DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
-	}
-	serial_out(up, UART_IER, iersave);
-
-	/*
-	 * Exar uarts have EFR in a weird location
-	 */
-	if (up->port.flags & UPF_EXAR_EFR) {
-		DEBUG_AUTOCONF("Exar XR17D15x ");
-		up->port.type = PORT_XR17D15X;
-		up->capabilities |= UART_CAP_AFE | UART_CAP_EFR |
-				    UART_CAP_SLEEP;
-
-		return;
-	}
-
-	/*
-	 * We distinguish between 16550A and U6 16550A by counting
-	 * how many bytes are in the FIFO.
-	 */
-	if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
-		up->port.type = PORT_U6_16550A;
-		up->capabilities |= UART_CAP_AFE;
-	}
-}
-
-/*
- * This routine is called by rs_init() to initialize a specific serial
- * port.  It determines what type of UART chip this serial port is
- * using: 8250, 16450, 16550, 16550A.  The important question is
- * whether or not this UART is a 16550A or not, since this will
- * determine whether or not we can use its FIFO features or not.
- */
-static void autoconfig(struct uart_8250_port *up)
-{
-	unsigned char status1, scratch, scratch2, scratch3;
-	unsigned char save_lcr, save_mcr;
-	struct uart_port *port = &up->port;
-	unsigned long flags;
-	unsigned int old_capabilities;
-
-	if (!port->iobase && !port->mapbase && !port->membase)
-		return;
-
-	DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
-		       serial_index(port), port->iobase, port->membase);
-
-	/*
-	 * We really do need global IRQs disabled here - we're going to
-	 * be frobbing the chips IRQ enable register to see if it exists.
-	 */
-	spin_lock_irqsave(&port->lock, flags);
-
-	up->capabilities = 0;
-	up->bugs = 0;
-
-	if (!(port->flags & UPF_BUGGY_UART)) {
-		/*
-		 * Do a simple existence test first; if we fail this,
-		 * there's no point trying anything else.
-		 *
-		 * 0x80 is used as a nonsense port to prevent against
-		 * false positives due to ISA bus float.  The
-		 * assumption is that 0x80 is a non-existent port;
-		 * which should be safe since include/asm/io.h also
-		 * makes this assumption.
-		 *
-		 * Note: this is safe as long as MCR bit 4 is clear
-		 * and the device is in "PC" mode.
-		 */
-		scratch = serial_in(up, UART_IER);
-		serial_out(up, UART_IER, 0);
-#ifdef __i386__
-		outb(0xff, 0x080);
-#endif
-		/*
-		 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
-		 * 16C754B) allow only to modify them if an EFR bit is set.
-		 */
-		scratch2 = serial_in(up, UART_IER) & 0x0f;
-		serial_out(up, UART_IER, 0x0F);
-#ifdef __i386__
-		outb(0, 0x080);
-#endif
-		scratch3 = serial_in(up, UART_IER) & 0x0f;
-		serial_out(up, UART_IER, scratch);
-		if (scratch2 != 0 || scratch3 != 0x0F) {
-			/*
-			 * We failed; there's nothing here
-			 */
-			spin_unlock_irqrestore(&port->lock, flags);
-			DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
-				       scratch2, scratch3);
-			goto out;
-		}
-	}
-
-	save_mcr = serial_in(up, UART_MCR);
-	save_lcr = serial_in(up, UART_LCR);
-
-	/*
-	 * Check to see if a UART is really there.  Certain broken
-	 * internal modems based on the Rockwell chipset fail this
-	 * test, because they apparently don't implement the loopback
-	 * test mode.  So this test is skipped on the COM 1 through
-	 * COM 4 ports.  This *should* be safe, since no board
-	 * manufacturer would be stupid enough to design a board
-	 * that conflicts with COM 1-4 --- we hope!
-	 */
-	if (!(port->flags & UPF_SKIP_TEST)) {
-		serial_out(up, UART_MCR, UART_MCR_LOOP | 0x0A);
-		status1 = serial_in(up, UART_MSR) & 0xF0;
-		serial_out(up, UART_MCR, save_mcr);
-		if (status1 != 0x90) {
-			spin_unlock_irqrestore(&port->lock, flags);
-			DEBUG_AUTOCONF("LOOP test failed (%02x) ",
-				       status1);
-			goto out;
-		}
-	}
-
-	/*
-	 * We're pretty sure there's a port here.  Lets find out what
-	 * type of port it is.  The IIR top two bits allows us to find
-	 * out if it's 8250 or 16450, 16550, 16550A or later.  This
-	 * determines what we test for next.
-	 *
-	 * We also initialise the EFR (if any) to zero for later.  The
-	 * EFR occupies the same register location as the FCR and IIR.
-	 */
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	serial_out(up, UART_EFR, 0);
-	serial_out(up, UART_LCR, 0);
-
-	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
-	scratch = serial_in(up, UART_IIR) >> 6;
-
-	switch (scratch) {
-	case 0:
-		autoconfig_8250(up);
-		break;
-	case 1:
-		port->type = PORT_UNKNOWN;
-		break;
-	case 2:
-		port->type = PORT_16550;
-		break;
-	case 3:
-		autoconfig_16550a(up);
-		break;
-	}
-
-#ifdef CONFIG_SERIAL_8250_RSA
-	/*
-	 * Only probe for RSA ports if we got the region.
-	 */
-	if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA &&
-	    __enable_rsa(up))
-		port->type = PORT_RSA;
-#endif
-
-	serial_out(up, UART_LCR, save_lcr);
-
-	port->fifosize = uart_config[up->port.type].fifo_size;
-	old_capabilities = up->capabilities;
-	up->capabilities = uart_config[port->type].flags;
-	up->tx_loadsz = uart_config[port->type].tx_loadsz;
-
-	if (port->type == PORT_UNKNOWN)
-		goto out_lock;
-
-	/*
-	 * Reset the UART.
-	 */
-#ifdef CONFIG_SERIAL_8250_RSA
-	if (port->type == PORT_RSA)
-		serial_out(up, UART_RSA_FRR, 0);
-#endif
-	serial_out(up, UART_MCR, save_mcr);
-	serial8250_clear_fifos(up);
-	serial_in(up, UART_RX);
-	if (up->capabilities & UART_CAP_UUE)
-		serial_out(up, UART_IER, UART_IER_UUE);
-	else
-		serial_out(up, UART_IER, 0);
-
-out_lock:
-	spin_unlock_irqrestore(&port->lock, flags);
-	if (up->capabilities != old_capabilities) {
-		printk(KERN_WARNING
-		       "ttyS%d: detected caps %08x should be %08x\n",
-		       serial_index(port), old_capabilities,
-		       up->capabilities);
-	}
-out:
-	DEBUG_AUTOCONF("iir=%d ", scratch);
-	DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name);
-}
-
-static void autoconfig_irq(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-	unsigned char save_mcr, save_ier;
-	unsigned char save_ICP = 0;
-	unsigned int ICP = 0;
-	unsigned long irqs;
-	int irq;
-
-	if (port->flags & UPF_FOURPORT) {
-		ICP = (port->iobase & 0xfe0) | 0x1f;
-		save_ICP = inb_p(ICP);
-		outb_p(0x80, ICP);
-		inb_p(ICP);
-	}
-
-	/* forget possible initially masked and pending IRQ */
-	probe_irq_off(probe_irq_on());
-	save_mcr = serial_in(up, UART_MCR);
-	save_ier = serial_in(up, UART_IER);
-	serial_out(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
-
-	irqs = probe_irq_on();
-	serial_out(up, UART_MCR, 0);
-	udelay(10);
-	if (port->flags & UPF_FOURPORT) {
-		serial_out(up, UART_MCR,
-			    UART_MCR_DTR | UART_MCR_RTS);
-	} else {
-		serial_out(up, UART_MCR,
-			    UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
-	}
-	serial_out(up, UART_IER, 0x0f);	/* enable all intrs */
-	serial_in(up, UART_LSR);
-	serial_in(up, UART_RX);
-	serial_in(up, UART_IIR);
-	serial_in(up, UART_MSR);
-	serial_out(up, UART_TX, 0xFF);
-	udelay(20);
-	irq = probe_irq_off(irqs);
-
-	serial_out(up, UART_MCR, save_mcr);
-	serial_out(up, UART_IER, save_ier);
-
-	if (port->flags & UPF_FOURPORT)
-		outb_p(save_ICP, ICP);
-
-	port->irq = (irq > 0) ? irq : 0;
-}
-
-static inline void __stop_tx(struct uart_8250_port *p)
-{
-	if (p->ier & UART_IER_THRI) {
-		p->ier &= ~UART_IER_THRI;
-		serial_out(p, UART_IER, p->ier);
-		serial8250_rpm_put_tx(p);
-	}
-}
-
-static void serial8250_stop_tx(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	serial8250_rpm_get(up);
-	__stop_tx(up);
-
-	/*
-	 * We really want to stop the transmitter from sending.
-	 */
-	if (port->type == PORT_16C950) {
-		up->acr |= UART_ACR_TXDIS;
-		serial_icr_write(up, UART_ACR, up->acr);
-	}
-	serial8250_rpm_put(up);
-}
-
-static void serial8250_start_tx(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	serial8250_rpm_get_tx(up);
-
-	if (up->dma && !up->dma->tx_dma(up))
-		return;
-
-	if (!(up->ier & UART_IER_THRI)) {
-		up->ier |= UART_IER_THRI;
-		serial_port_out(port, UART_IER, up->ier);
-
-		if (up->bugs & UART_BUG_TXEN) {
-			unsigned char lsr;
-			lsr = serial_in(up, UART_LSR);
-			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
-			if (lsr & UART_LSR_THRE)
-				serial8250_tx_chars(up);
-		}
-	}
-
-	/*
-	 * Re-enable the transmitter if we disabled it.
-	 */
-	if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
-		up->acr &= ~UART_ACR_TXDIS;
-		serial_icr_write(up, UART_ACR, up->acr);
-	}
-}
-
-static void serial8250_throttle(struct uart_port *port)
-{
-	port->throttle(port);
-}
-
-static void serial8250_unthrottle(struct uart_port *port)
-{
-	port->unthrottle(port);
-}
-
-static void serial8250_stop_rx(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	serial8250_rpm_get(up);
-
-	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
-	up->port.read_status_mask &= ~UART_LSR_DR;
-	serial_port_out(port, UART_IER, up->ier);
-
-	serial8250_rpm_put(up);
-}
-
-static void serial8250_disable_ms(struct uart_port *port)
-{
-	struct uart_8250_port *up =
-		container_of(port, struct uart_8250_port, port);
-
-	/* no MSR capabilities */
-	if (up->bugs & UART_BUG_NOMSR)
-		return;
-
-	up->ier &= ~UART_IER_MSI;
-	serial_port_out(port, UART_IER, up->ier);
-}
-
-static void serial8250_enable_ms(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	/* no MSR capabilities */
-	if (up->bugs & UART_BUG_NOMSR)
-		return;
-
-	up->ier |= UART_IER_MSI;
-
-	serial8250_rpm_get(up);
-	serial_port_out(port, UART_IER, up->ier);
-	serial8250_rpm_put(up);
-}
-
-/*
- * serial8250_rx_chars: processes according to the passed in LSR
- * value, and returns the remaining LSR bits not handled
- * by this Rx routine.
- */
-unsigned char
-serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
-{
-	struct uart_port *port = &up->port;
-	unsigned char ch;
-	int max_count = 256;
-	char flag;
-
-	do {
-		if (likely(lsr & UART_LSR_DR))
-			ch = serial_in(up, UART_RX);
-		else
-			/*
-			 * Intel 82571 has a Serial Over Lan device that will
-			 * set UART_LSR_BI without setting UART_LSR_DR when
-			 * it receives a break. To avoid reading from the
-			 * receive buffer without UART_LSR_DR bit set, we
-			 * just force the read character to be 0
-			 */
-			ch = 0;
-
-		flag = TTY_NORMAL;
-		port->icount.rx++;
-
-		lsr |= up->lsr_saved_flags;
-		up->lsr_saved_flags = 0;
-
-		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
-			if (lsr & UART_LSR_BI) {
-				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
-				port->icount.brk++;
-				/*
-				 * We do the SysRQ and SAK checking
-				 * here because otherwise the break
-				 * may get masked by ignore_status_mask
-				 * or read_status_mask.
-				 */
-				if (uart_handle_break(port))
-					goto ignore_char;
-			} else if (lsr & UART_LSR_PE)
-				port->icount.parity++;
-			else if (lsr & UART_LSR_FE)
-				port->icount.frame++;
-			if (lsr & UART_LSR_OE)
-				port->icount.overrun++;
-
-			/*
-			 * Mask off conditions which should be ignored.
-			 */
-			lsr &= port->read_status_mask;
-
-			if (lsr & UART_LSR_BI) {
-				DEBUG_INTR("handling break....");
-				flag = TTY_BREAK;
-			} else if (lsr & UART_LSR_PE)
-				flag = TTY_PARITY;
-			else if (lsr & UART_LSR_FE)
-				flag = TTY_FRAME;
-		}
-		if (uart_handle_sysrq_char(port, ch))
-			goto ignore_char;
-
-		uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
-
-ignore_char:
-		lsr = serial_in(up, UART_LSR);
-	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (--max_count > 0));
-	spin_unlock(&port->lock);
-	tty_flip_buffer_push(&port->state->port);
-	spin_lock(&port->lock);
-	return lsr;
-}
-EXPORT_SYMBOL_GPL(serial8250_rx_chars);
-
-void serial8250_tx_chars(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-	struct circ_buf *xmit = &port->state->xmit;
-	int count;
-
-	if (port->x_char) {
-		serial_out(up, UART_TX, port->x_char);
-		port->icount.tx++;
-		port->x_char = 0;
-		return;
-	}
-	if (uart_tx_stopped(port)) {
-		serial8250_stop_tx(port);
-		return;
-	}
-	if (uart_circ_empty(xmit)) {
-		__stop_tx(up);
-		return;
-	}
-
-	count = up->tx_loadsz;
-	do {
-		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
-		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-		port->icount.tx++;
-		if (uart_circ_empty(xmit))
-			break;
-		if (up->capabilities & UART_CAP_HFIFO) {
-			if ((serial_port_in(port, UART_LSR) & BOTH_EMPTY) !=
-			    BOTH_EMPTY)
-				break;
-		}
-	} while (--count > 0);
-
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
-		uart_write_wakeup(port);
-
-	DEBUG_INTR("THRE...");
-
-	/*
-	 * With RPM enabled, we have to wait until the FIFO is empty before the
-	 * HW can go idle. So we get here once again with empty FIFO and disable
-	 * the interrupt and RPM in __stop_tx()
-	 */
-	if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
-		__stop_tx(up);
-}
-EXPORT_SYMBOL_GPL(serial8250_tx_chars);
-
-/* Caller holds uart port lock */
-unsigned int serial8250_modem_status(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-	unsigned int status = serial_in(up, UART_MSR);
-
-	status |= up->msr_saved_flags;
-	up->msr_saved_flags = 0;
-	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
-	    port->state != NULL) {
-		if (status & UART_MSR_TERI)
-			port->icount.rng++;
-		if (status & UART_MSR_DDSR)
-			port->icount.dsr++;
-		if (status & UART_MSR_DDCD)
-			uart_handle_dcd_change(port, status & UART_MSR_DCD);
-		if (status & UART_MSR_DCTS)
-			uart_handle_cts_change(port, status & UART_MSR_CTS);
-
-		wake_up_interruptible(&port->state->port.delta_msr_wait);
-	}
-
-	return status;
-}
-EXPORT_SYMBOL_GPL(serial8250_modem_status);
-
-/*
- * This handles the interrupt from one port.
- */
-int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
-{
-	unsigned char status;
-	unsigned long flags;
-	struct uart_8250_port *up = up_to_u8250p(port);
-	int dma_err = 0;
-
-	if (iir & UART_IIR_NO_INT)
-		return 0;
-
-	spin_lock_irqsave(&port->lock, flags);
-
-	status = serial_port_in(port, UART_LSR);
-
-	DEBUG_INTR("status = %x...", status);
-
-	if (status & (UART_LSR_DR | UART_LSR_BI)) {
-		if (up->dma)
-			dma_err = up->dma->rx_dma(up, iir);
-
-		if (!up->dma || dma_err)
-			status = serial8250_rx_chars(up, status);
-	}
-	serial8250_modem_status(up);
-	if ((!up->dma || (up->dma && up->dma->tx_err)) &&
-	    (status & UART_LSR_THRE))
-		serial8250_tx_chars(up);
-
-	spin_unlock_irqrestore(&port->lock, flags);
-	return 1;
-}
-EXPORT_SYMBOL_GPL(serial8250_handle_irq);
-
-static int serial8250_default_handle_irq(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned int iir;
-	int ret;
-
-	serial8250_rpm_get(up);
-
-	iir = serial_port_in(port, UART_IIR);
-	ret = serial8250_handle_irq(port, iir);
-
-	serial8250_rpm_put(up);
-	return ret;
-}
-
-/*
- * These Exar UARTs have an extra interrupt indicator that could
- * fire for a few unimplemented interrupts.  One of which is a
- * wakeup event when coming out of sleep.  Put this here just
- * to be on the safe side that these interrupts don't go unhandled.
- */
-static int exar_handle_irq(struct uart_port *port)
-{
-	unsigned char int0, int1, int2, int3;
-	unsigned int iir = serial_port_in(port, UART_IIR);
-	int ret;
-
-	ret = serial8250_handle_irq(port, iir);
-
-	if ((port->type == PORT_XR17V35X) ||
-	   (port->type == PORT_XR17D15X)) {
-		int0 = serial_port_in(port, 0x80);
-		int1 = serial_port_in(port, 0x81);
-		int2 = serial_port_in(port, 0x82);
-		int3 = serial_port_in(port, 0x83);
-	}
-
-	return ret;
-}
 
 /*
  * This is the serial driver's interrupt routine.
···
 		serial_unlink_irq_chain(up);
 }
 
-static unsigned int serial8250_tx_empty(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned long flags;
-	unsigned int lsr;
-
-	serial8250_rpm_get(up);
-
-	spin_lock_irqsave(&port->lock, flags);
-	lsr = serial_port_in(port, UART_LSR);
-	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
-	spin_unlock_irqrestore(&port->lock, flags);
-
-	serial8250_rpm_put(up);
-
-	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
-}
-
-static unsigned int serial8250_get_mctrl(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned int status;
-	unsigned int ret;
-
-	serial8250_rpm_get(up);
-	status = serial8250_modem_status(up);
-	serial8250_rpm_put(up);
-
-	ret = 0;
-	if (status & UART_MSR_DCD)
-		ret |= TIOCM_CAR;
-	if (status & UART_MSR_RI)
-		ret |= TIOCM_RNG;
-	if (status & UART_MSR_DSR)
-		ret |= TIOCM_DSR;
-	if (status & UART_MSR_CTS)
-		ret |= TIOCM_CTS;
-	return ret;
-}
-
-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;
-
-	if (mctrl & TIOCM_RTS)
-		mcr |= UART_MCR_RTS;
-	if (mctrl & TIOCM_DTR)
-		mcr |= UART_MCR_DTR;
-	if (mctrl & TIOCM_OUT1)
-		mcr |= UART_MCR_OUT1;
-	if (mctrl & TIOCM_OUT2)
-		mcr |= UART_MCR_OUT2;
-	if (mctrl & TIOCM_LOOP)
-		mcr |= UART_MCR_LOOP;
-
-	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)
-		port->set_mctrl(port, mctrl);
-	else
-		serial8250_do_set_mctrl(port, mctrl);
-}
-
-static void serial8250_break_ctl(struct uart_port *port, int break_state)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned long flags;
-
-	serial8250_rpm_get(up);
-	spin_lock_irqsave(&port->lock, flags);
-	if (break_state == -1)
-		up->lcr |= UART_LCR_SBC;
-	else
-		up->lcr &= ~UART_LCR_SBC;
-	serial_port_out(port, UART_LCR, up->lcr);
-	spin_unlock_irqrestore(&port->lock, flags);
-	serial8250_rpm_put(up);
-}
-
-/*
- *	Wait for transmitter & holding register to empty
- */
-static void wait_for_xmitr(struct uart_8250_port *up, int bits)
-{
-	unsigned int status, tmout = 10000;
-
-	/* Wait up to 10ms for the character(s) to be sent. */
-	for (;;) {
-		status = serial_in(up, UART_LSR);
-
-		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
-
-		if ((status & bits) == bits)
-			break;
-		if (--tmout == 0)
-			break;
-		udelay(1);
-	}
-
-	/* Wait up to 1s for flow control if necessary */
-	if (up->port.flags & UPF_CONS_FLOW) {
-		unsigned int tmout;
-		for (tmout = 1000000; tmout; tmout--) {
-			unsigned int msr = serial_in(up, UART_MSR);
-			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
-			if (msr & UART_MSR_CTS)
-				break;
-			udelay(1);
-			touch_nmi_watchdog();
-		}
-	}
-}
-
-#ifdef CONFIG_CONSOLE_POLL
-/*
- * Console polling routines for writing and reading from the uart while
- * in an interrupt or debug context.
- */
-
-static int serial8250_get_poll_char(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned char lsr;
-	int status;
-
-	serial8250_rpm_get(up);
-
-	lsr = serial_port_in(port, UART_LSR);
-
-	if (!(lsr & UART_LSR_DR)) {
-		status = NO_POLL_CHAR;
-		goto out;
-	}
-
-	status = serial_port_in(port, UART_RX);
-out:
-	serial8250_rpm_put(up);
-	return status;
-}
-
-
-static void serial8250_put_poll_char(struct uart_port *port,
-			 unsigned char c)
-{
-	unsigned int ier;
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	serial8250_rpm_get(up);
-	/*
-	 *	First save the IER then disable the interrupts
-	 */
-	ier = serial_port_in(port, UART_IER);
-	if (up->capabilities & UART_CAP_UUE)
-		serial_port_out(port, UART_IER, UART_IER_UUE);
-	else
-		serial_port_out(port, UART_IER, 0);
-
-	wait_for_xmitr(up, BOTH_EMPTY);
-	/*
-	 *	Send the character out.
-	 */
-	serial_port_out(port, UART_TX, c);
-
-	/*
-	 *	Finally, wait for transmitter to become empty
-	 *	and restore the IER
-	 */
-	wait_for_xmitr(up, BOTH_EMPTY);
-	serial_port_out(port, UART_IER, ier);
-	serial8250_rpm_put(up);
-}
-
-#endif /* CONFIG_CONSOLE_POLL */
-
-int serial8250_do_startup(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned long flags;
-	unsigned char lsr, iir;
-	int retval;
-
-	if (port->type == PORT_8250_CIR)
-		return -ENODEV;
-
-	if (!port->fifosize)
-		port->fifosize = uart_config[port->type].fifo_size;
-	if (!up->tx_loadsz)
-		up->tx_loadsz = uart_config[port->type].tx_loadsz;
-	if (!up->capabilities)
-		up->capabilities = uart_config[port->type].flags;
-	up->mcr = 0;
-
-	if (port->iotype != up->cur_iotype)
-		set_io_from_upio(port);
-
-	serial8250_rpm_get(up);
-	if (port->type == PORT_16C950) {
-		/* Wake up and initialize UART */
-		up->acr = 0;
-		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_port_out(port, UART_EFR, UART_EFR_ECB);
-		serial_port_out(port, UART_IER, 0);
-		serial_port_out(port, UART_LCR, 0);
-		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
-		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
-		serial_port_out(port, UART_EFR, UART_EFR_ECB);
-		serial_port_out(port, UART_LCR, 0);
-	}
-
-#ifdef CONFIG_SERIAL_8250_RSA
-	/*
-	 * If this is an RSA port, see if we can kick it up to the
-	 * higher speed clock.
-	 */
-	enable_rsa(up);
-#endif
-	/*
-	 * Clear the FIFO buffers and disable them.
-	 * (they will be reenabled in set_termios())
-	 */
-	serial8250_clear_fifos(up);
-
-	/*
-	 * Clear the interrupt registers.
-	 */
-	serial_port_in(port, UART_LSR);
-	serial_port_in(port, UART_RX);
-	serial_port_in(port, UART_IIR);
-	serial_port_in(port, UART_MSR);
-
-	/*
-	 * At this point, there's no way the LSR could still be 0xff;
-	 * if it is, then bail out, because there's likely no UART
-	 * here.
-	 */
-	if (!(port->flags & UPF_BUGGY_UART) &&
-	    (serial_port_in(port, UART_LSR) == 0xff)) {
-		printk_ratelimited(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
-				   serial_index(port));
-		retval = -ENODEV;
-		goto out;
-	}
-
-	/*
-	 * For a XR16C850, we need to set the trigger levels
-	 */
-	if (port->type == PORT_16850) {
-		unsigned char fctr;
-
-		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-
-		fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
-		serial_port_out(port, UART_FCTR,
-				fctr | UART_FCTR_TRGD | UART_FCTR_RX);
-		serial_port_out(port, UART_TRG, UART_TRG_96);
-		serial_port_out(port, UART_FCTR,
-				fctr | UART_FCTR_TRGD | UART_FCTR_TX);
-		serial_port_out(port, UART_TRG, UART_TRG_96);
-
-		serial_port_out(port, UART_LCR, 0);
-	}
-
-	if (port->irq) {
-		unsigned char iir1;
-		/*
-		 * Test for UARTs that do not reassert THRE when the
-		 * transmitter is idle and the interrupt has already
-		 * been cleared.  Real 16550s should always reassert
-		 * this interrupt whenever the transmitter is idle and
-		 * the interrupt is enabled.  Delays are necessary to
-		 * allow register changes to become visible.
-		 */
-		spin_lock_irqsave(&port->lock, flags);
-		if (up->port.irqflags & IRQF_SHARED)
-			disable_irq_nosync(port->irq);
-
-		wait_for_xmitr(up, UART_LSR_THRE);
-		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
-		udelay(1); /* allow THRE to set */
-		iir1 = serial_port_in(port, UART_IIR);
-		serial_port_out(port, UART_IER, 0);
-		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
-		udelay(1); /* allow a working UART time to re-assert THRE */
-		iir = serial_port_in(port, UART_IIR);
-		serial_port_out(port, UART_IER, 0);
-
-		if (port->irqflags & IRQF_SHARED)
-			enable_irq(port->irq);
-		spin_unlock_irqrestore(&port->lock, flags);
-
-		/*
-		 * If the interrupt is not reasserted, or we otherwise
-		 * don't trust the iir, setup a timer to kick the UART
-		 * on a regular basis.
-		 */
-		if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||
-		    up->port.flags & UPF_BUG_THRE) {
-			up->bugs |= UART_BUG_THRE;
-		}
-	}
-
-	retval = up->ops->setup_irq(up);
-	if (retval)
-		goto out;
-
-	/*
-	 * Now, initialize the UART
-	 */
-	serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
-
-	spin_lock_irqsave(&port->lock, flags);
-	if (up->port.flags & UPF_FOURPORT) {
-		if (!up->port.irq)
-			up->port.mctrl |= TIOCM_OUT1;
-	} else
-		/*
-		 * Most PC uarts need OUT2 raised to enable interrupts.
-		 */
-		if (port->irq)
-			up->port.mctrl |= TIOCM_OUT2;
-
-	serial8250_set_mctrl(port, port->mctrl);
-
-	/* Serial over Lan (SoL) hack:
-	   Intel 8257x Gigabit ethernet chips have a
-	   16550 emulation, to be used for Serial Over Lan.
-	   Those chips take a longer time than a normal
-	   serial device to signalize that a transmission
-	   data was queued. Due to that, the above test generally
-	   fails. One solution would be to delay the reading of
-	   iir. However, this is not reliable, since the timeout
-	   is variable. So, let's just don't test if we receive
-	   TX irq. This way, we'll never enable UART_BUG_TXEN.
-	 */
-	if (up->port.flags & UPF_NO_TXEN_TEST)
-		goto dont_test_tx_en;
-
-	/*
-	 * Do a quick test to see if we receive an
-	 * interrupt when we enable the TX irq.
-	 */
-	serial_port_out(port, UART_IER, UART_IER_THRI);
-	lsr = serial_port_in(port, UART_LSR);
-	iir = serial_port_in(port, UART_IIR);
-	serial_port_out(port, UART_IER, 0);
-
-	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
-		if (!(up->bugs & UART_BUG_TXEN)) {
-			up->bugs |= UART_BUG_TXEN;
-			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
-				 serial_index(port));
-		}
-	} else {
-		up->bugs &= ~UART_BUG_TXEN;
-	}
-
-dont_test_tx_en:
-	spin_unlock_irqrestore(&port->lock, flags);
-
-	/*
-	 * Clear the interrupt registers again for luck, and clear the
-	 * saved flags to avoid getting false values from polling
-	 * routines or the previous session.
-	 */
-	serial_port_in(port, UART_LSR);
-	serial_port_in(port, UART_RX);
-	serial_port_in(port, UART_IIR);
-	serial_port_in(port, UART_MSR);
-	up->lsr_saved_flags = 0;
-	up->msr_saved_flags = 0;
-
-	/*
-	 * Request DMA channels for both RX and TX.
-	 */
-	if (up->dma) {
-		retval = serial8250_request_dma(up);
-		if (retval) {
-			pr_warn_ratelimited("ttyS%d - failed to request DMA\n",
-					    serial_index(port));
-			up->dma = NULL;
-		}
-	}
-
-	/*
-	 * Finally, enable interrupts.  Note: Modem status interrupts
-	 * are set via set_termios(), which will be occurring imminently
-	 * anyway, so we don't enable them here.
-	 */
-	up->ier = UART_IER_RLSI | UART_IER_RDI;
-	serial_port_out(port, UART_IER, up->ier);
-
-	if (port->flags & UPF_FOURPORT) {
-		unsigned int icp;
-		/*
-		 * Enable interrupts on the AST Fourport board
-		 */
-		icp = (port->iobase & 0xfe0) | 0x01f;
-		outb_p(0x80, icp);
-		inb_p(icp);
-	}
-	retval = 0;
-out:
-	serial8250_rpm_put(up);
-	return retval;
-}
-EXPORT_SYMBOL_GPL(serial8250_do_startup);
-
-static int serial8250_startup(struct uart_port *port)
-{
-	if (port->startup)
-		return port->startup(port);
-	return serial8250_do_startup(port);
-}
-
-void serial8250_do_shutdown(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned long flags;
-
-	serial8250_rpm_get(up);
-	/*
-	 * Disable interrupts from this port
-	 */
-	up->ier = 0;
-	serial_port_out(port, UART_IER, 0);
-
-	if (up->dma)
-		serial8250_release_dma(up);
-
-	spin_lock_irqsave(&port->lock, flags);
-	if (port->flags & UPF_FOURPORT) {
-		/* reset interrupts on the AST Fourport board */
-		inb((port->iobase & 0xfe0) | 0x1f);
-		port->mctrl |= TIOCM_OUT1;
-	} else
-		port->mctrl &= ~TIOCM_OUT2;
-
-	serial8250_set_mctrl(port, port->mctrl);
-	spin_unlock_irqrestore(&port->lock, flags);
-
-	/*
-	 * Disable break condition and FIFOs
-	 */
-	serial_port_out(port, UART_LCR,
-			serial_port_in(port, UART_LCR) & ~UART_LCR_SBC);
-	serial8250_clear_fifos(up);
-
-#ifdef CONFIG_SERIAL_8250_RSA
-	/*
-	 * Reset the RSA board back to 115kbps compat mode.
-	 */
-	disable_rsa(up);
-#endif
-
-	/*
-	 * Read data port to reset things, and then unlink from
-	 * the IRQ chain.
-	 */
-	serial_port_in(port, UART_RX);
-	serial8250_rpm_put(up);
-
-	up->ops->release_irq(up);
-}
-EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
-
-static void serial8250_shutdown(struct uart_port *port)
-{
-	if (port->shutdown)
-		port->shutdown(port);
-	else
-		serial8250_do_shutdown(port);
-}
-
-/*
- * 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))
-		quot = 0x8001;
-	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;
-}
-
-static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
-					    tcflag_t c_cflag)
-{
-	unsigned char cval;
-
-	switch (c_cflag & CSIZE) {
-	case CS5:
-		cval = UART_LCR_WLEN5;
-		break;
-	case CS6:
-		cval = UART_LCR_WLEN6;
-		break;
-	case CS7:
-		cval = UART_LCR_WLEN7;
-		break;
-	default:
-	case CS8:
-		cval = UART_LCR_WLEN8;
-		break;
-	}
-
-	if (c_cflag & CSTOPB)
-		cval |= UART_LCR_STOP;
-	if (c_cflag & PARENB) {
-		cval |= UART_LCR_PARITY;
-		if (up->bugs & UART_BUG_PARITY)
-			up->fifo_bug = true;
-	}
-	if (!(c_cflag & PARODD))
-		cval |= UART_LCR_EPAR;
-#ifdef 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(up, baud, &frac);
-
-	/*
-	 * Ok, we're now changing the port state.  Do it with
-	 * interrupts disabled.
-	 */
-	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 ((baud < 2400 && !up->dma) || up->fifo_bug) {
-			up->fcr &= ~UART_FCR_TRIGGER_MASK;
-			up->fcr |= UART_FCR_TRIGGER_1;
-		}
-	}
-
-	/*
-	 * MCR-based auto flow control.  When AFE is enabled, RTS will be
-	 * deasserted when the receive FIFO contains more characters than
-	 * the trigger, or the MCR RTS bit is cleared.  In the case where
-	 * the remote UART is not using CTS auto flow control, we must
-	 * have sufficient FIFO entries for the latency of the remote
-	 * UART to respond.  IOW, at least 32 bytes of FIFO.
-	 */
-	if (up->capabilities & UART_CAP_AFE && port->fifosize >= 32) {
-		up->mcr &= ~UART_MCR_AFE;
-		if (termios->c_cflag & CRTSCTS)
-			up->mcr |= UART_MCR_AFE;
-	}
-
-	/*
-	 * Update the per-port timeout.
-	 */
-	uart_update_timeout(port, termios->c_cflag, baud);
-
-	port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
-	if (termios->c_iflag & INPCK)
-		port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
-	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
-		port->read_status_mask |= UART_LSR_BI;
-
-	/*
-	 * Characteres to ignore
-	 */
-	port->ignore_status_mask = 0;
-	if (termios->c_iflag & IGNPAR)
-		port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
-	if (termios->c_iflag & IGNBRK) {
-		port->ignore_status_mask |= UART_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 |= UART_LSR_OE;
-	}
-
-	/*
-	 * ignore all characters if CREAD is not set
-	 */
-	if ((termios->c_cflag & CREAD) == 0)
-		port->ignore_status_mask |= UART_LSR_DR;
-
-	/*
-	 * CTS flow control flag and modem status interrupts
-	 */
-	up->ier &= ~UART_IER_MSI;
-	if (!(up->bugs & UART_BUG_NOMSR) &&
-			UART_ENABLE_MS(&up->port, termios->c_cflag))
-		up->ier |= UART_IER_MSI;
-	if (up->capabilities & UART_CAP_UUE)
-		up->ier |= UART_IER_UUE;
-	if (up->capabilities & UART_CAP_RTOIE)
-		up->ier |= UART_IER_RTOIE;
-
-	serial_port_out(port, UART_IER, up->ier);
-
-	if (up->capabilities & UART_CAP_EFR) {
-		unsigned char efr = 0;
-		/*
-		 * TI16C752/Startech hardware flow control.  FIXME:
-		 * - TI16C752 requires control thresholds to be set.
-		 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
-		 */
-		if (termios->c_cflag & CRTSCTS)
-			efr |= UART_EFR_CTS;
-
-		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
-		if (port->flags & UPF_EXAR_EFR)
-			serial_port_out(port, UART_XR_EFR, efr);
-		else
-			serial_port_out(port, UART_EFR, efr);
-	}
-
-	serial8250_set_divisor(port, baud, quot, frac);
-
-	/*
-	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
-	 * is written without DLAB set, this mode will be disabled.
-	 */
-	if (port->type == PORT_16750)
-		serial_port_out(port, UART_FCR, up->fcr);
-
-	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)
-			serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
-		serial_port_out(port, UART_FCR, up->fcr);	/* set fcr */
-	}
-	serial8250_set_mctrl(port, port->mctrl);
-	spin_unlock_irqrestore(&port->lock, flags);
-	serial8250_rpm_put(up);
-
-	/* Don't rewrite B0 */
-	if (tty_termios_baud_rate(termios))
-		tty_termios_encode_baud_rate(termios, baud, baud);
-}
-EXPORT_SYMBOL(serial8250_do_set_termios);
-
-static void
-serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
-		       struct ktermios *old)
-{
-	if (port->set_termios)
-		port->set_termios(port, termios, old);
-	else
-		serial8250_do_set_termios(port, termios, old);
-}
-
-static void
-serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
-{
-	if (termios->c_line == N_PPS) {
-		port->flags |= UPF_HARDPPS_CD;
-		spin_lock_irq(&port->lock);
-		serial8250_enable_ms(port);
-		spin_unlock_irq(&port->lock);
-	} else {
-		port->flags &= ~UPF_HARDPPS_CD;
-		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
-			spin_lock_irq(&port->lock);
-			serial8250_disable_ms(port);
-			spin_unlock_irq(&port->lock);
-		}
-	}
-}
-
-
-void serial8250_do_pm(struct uart_port *port, unsigned int state,
-		      unsigned int oldstate)
-{
-	struct uart_8250_port *p = up_to_u8250p(port);
-
-	serial8250_set_sleep(p, state != 0);
-}
-EXPORT_SYMBOL(serial8250_do_pm);
-
-static void
-serial8250_pm(struct uart_port *port, unsigned int state,
-	      unsigned int oldstate)
-{
-	if (port->pm)
-		port->pm(port, state, oldstate);
-	else
-		serial8250_do_pm(port, state, oldstate);
-}
-
-static unsigned int serial8250_port_size(struct uart_8250_port *pt)
-{
-	if (pt->port.mapsize)
-		return pt->port.mapsize;
-	if (pt->port.iotype == UPIO_AU) {
-		if (pt->port.type == PORT_RT2880)
-			return 0x100;
-		return 0x1000;
-	}
-	if (is_omap1_8250(pt))
-		return 0x16 << pt->port.regshift;
-
-	return 8 << pt->port.regshift;
-}
-
-/*
- * Resource handling.
- */
-static int serial8250_request_std_resource(struct uart_8250_port *up)
-{
-	unsigned int size = serial8250_port_size(up);
-	struct uart_port *port = &up->port;
-	int ret = 0;
-
-	switch (port->iotype) {
-	case UPIO_AU:
-	case UPIO_TSI:
-	case UPIO_MEM32:
-	case UPIO_MEM32BE:
-	case UPIO_MEM:
-		if (!port->mapbase)
-			break;
-
-		if (!request_mem_region(port->mapbase, size, "serial")) {
-			ret = -EBUSY;
-			break;
-		}
-
-		if (port->flags & UPF_IOREMAP) {
-			port->membase = ioremap_nocache(port->mapbase, size);
-			if (!port->membase) {
-				release_mem_region(port->mapbase, size);
-				ret = -ENOMEM;
-			}
-		}
-		break;
-
-	case UPIO_HUB6:
-	case UPIO_PORT:
-		if (!request_region(port->iobase, size, "serial"))
-			ret = -EBUSY;
-		break;
-	}
-	return ret;
-}
-
-static void serial8250_release_std_resource(struct uart_8250_port *up)
-{
-	unsigned int size = serial8250_port_size(up);
-	struct uart_port *port = &up->port;
-
-	switch (port->iotype) {
-	case UPIO_AU:
-	case UPIO_TSI:
-	case UPIO_MEM32:
-	case UPIO_MEM32BE:
-	case UPIO_MEM:
-		if (!port->mapbase)
-			break;
-
-		if (port->flags & UPF_IOREMAP) {
-			iounmap(port->membase);
-			port->membase = NULL;
-		}
-
-		release_mem_region(port->mapbase, size);
-		break;
-
-	case UPIO_HUB6:
-	case UPIO_PORT:
-		release_region(port->iobase, size);
-		break;
-	}
-}
-
 #ifdef CONFIG_SERIAL_8250_RSA
 static int serial8250_request_rsa_resource(struct uart_8250_port *up)
 {
···
 	}
 }
 #endif
-
-static void serial8250_release_port(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	serial8250_release_std_resource(up);
-}
-
-static int serial8250_request_port(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	int ret;
-
-	if (port->type == PORT_8250_CIR)
-		return -ENODEV;
-
-	ret = serial8250_request_std_resource(up);
-
-	return ret;
-}
-
-static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
-{
-	const struct serial8250_config *conf_type = &uart_config[up->port.type];
-	unsigned char bytes;
-
-	bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)];
-
-	return bytes ? bytes : -EOPNOTSUPP;
-}
-
-static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes)
-{
-	const struct serial8250_config *conf_type = &uart_config[up->port.type];
-	int i;
-
-	if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)])
-		return -EOPNOTSUPP;
-
-	for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) {
-		if (bytes < conf_type->rxtrig_bytes[i])
-			/* Use the nearest lower value */
-			return (--i) << UART_FCR_R_TRIG_SHIFT;
-	}
-
-	return UART_FCR_R_TRIG_11;
-}
-
-static int do_get_rxtrig(struct tty_port *port)
-{
-	struct uart_state *state = container_of(port, struct uart_state, port);
-	struct uart_port *uport = state->uart_port;
-	struct uart_8250_port *up =
-		container_of(uport, struct uart_8250_port, port);
-
-	if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
-		return -EINVAL;
-
-	return fcr_get_rxtrig_bytes(up);
-}
-
-static int do_serial8250_get_rxtrig(struct tty_port *port)
-{
-	int rxtrig_bytes;
-
-	mutex_lock(&port->mutex);
-	rxtrig_bytes = do_get_rxtrig(port);
-	mutex_unlock(&port->mutex);
-
-	return rxtrig_bytes;
-}
-
-static ssize_t serial8250_get_attr_rx_trig_bytes(struct device *dev,
-	struct device_attribute *attr, char *buf)
-{
-	struct tty_port *port = dev_get_drvdata(dev);
-	int rxtrig_bytes;
-
-	rxtrig_bytes = do_serial8250_get_rxtrig(port);
-	if (rxtrig_bytes < 0)
-		return rxtrig_bytes;
-
-	return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes);
-}
-
-static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
-{
-	struct uart_state *state = container_of(port, struct uart_state, port);
-	struct uart_port *uport = state->uart_port;
-	struct uart_8250_port *up =
-		container_of(uport, struct uart_8250_port, port);
-	int rxtrig;
-
-	if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 ||
-	    up->fifo_bug)
-		return -EINVAL;
-
-	rxtrig = bytes_to_fcr_rxtrig(up, bytes);
-	if (rxtrig < 0)
-		return rxtrig;
-
-	serial8250_clear_fifos(up);
-	up->fcr &= ~UART_FCR_TRIGGER_MASK;
-	up->fcr |= (unsigned char)rxtrig;
-	serial_out(up, UART_FCR, up->fcr);
-	return 0;
-}
-
-static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes)
-{
-	int ret;
-
-	mutex_lock(&port->mutex);
-	ret = do_set_rxtrig(port, bytes);
-	mutex_unlock(&port->mutex);
-
-	return ret;
-}
-
-static ssize_t serial8250_set_attr_rx_trig_bytes(struct device *dev,
-	struct device_attribute *attr, const char *buf, size_t count)
-{
-	struct tty_port *port = dev_get_drvdata(dev);
-	unsigned char bytes;
-	int ret;
-
-	if (!count)
-		return -EINVAL;
-
-	ret = kstrtou8(buf, 10, &bytes);
-	if (ret < 0)
-		return ret;
-
-	ret = do_serial8250_set_rxtrig(port, bytes);
-	if (ret < 0)
-		return ret;
-
-	return count;
-}
-
-static DEVICE_ATTR(rx_trig_bytes, S_IRUSR | S_IWUSR | S_IRGRP,
-		   serial8250_get_attr_rx_trig_bytes,
-		   serial8250_set_attr_rx_trig_bytes);
-
-static struct attribute *serial8250_dev_attrs[] = {
-	&dev_attr_rx_trig_bytes.attr,
-	NULL,
-	};
-
-static struct attribute_group serial8250_dev_attr_group = {
-	.attrs = serial8250_dev_attrs,
-	};
-
-static void register_dev_spec_attr_grp(struct uart_8250_port *up)
-{
-	const struct serial8250_config *conf_type = &uart_config[up->port.type];
-
-	if (conf_type->rxtrig_bytes[0])
-		up->port.attr_group = &serial8250_dev_attr_group;
-}
-
-static void serial8250_config_port(struct uart_port *port, int flags)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	int ret;
-
-	if (port->type == PORT_8250_CIR)
-		return;
-
-	/*
-	 * Find the region that we can probe for.  This in turn
-	 * tells us whether we can probe for the type of port.
-	 */
-	ret = serial8250_request_std_resource(up);
-	if (ret < 0)
-		return;
-
-	if (port->iotype != up->cur_iotype)
-		set_io_from_upio(port);
-
-	if (flags & UART_CONFIG_TYPE)
-		autoconfig(up);
-
-	/* if access method is AU, it is a 16550 with a quirk */
-	if (port->type == PORT_16550A && port->iotype == UPIO_AU)
-		up->bugs |= UART_BUG_NOMSR;
-
-	/* HW bugs may trigger IRQ while IIR == NO_INT */
-	if (port->type == PORT_TEGRA)
-		up->bugs |= UART_BUG_NOMSR;
-
-	if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
-		autoconfig_irq(up);
-
-	if (port->type == PORT_UNKNOWN)
-		serial8250_release_std_resource(up);
-
-	/* Fixme: probably not the best place for this */
-	if ((port->type == PORT_XR17V35X) ||
-	   (port->type == PORT_XR17D15X))
-		port->handle_irq = exar_handle_irq;
-
-	register_dev_spec_attr_grp(up);
-	up->fcr = uart_config[up->port.type].fcr;
-}
-
-static int
-serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
-{
-	if (ser->irq >= nr_irqs || ser->irq < 0 ||
-	    ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
-	    ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
-	    ser->type == PORT_STARTECH)
-		return -EINVAL;
-	return 0;
-}
-
-static const char *
-serial8250_type(struct uart_port *port)
-{
-	int type = port->type;
-
-	if (type >= ARRAY_SIZE(uart_config))
-		type = 0;
-	return uart_config[type].name;
-}
-
-static const struct uart_ops serial8250_pops = {
-	.tx_empty	= serial8250_tx_empty,
-	.set_mctrl	= serial8250_set_mctrl,
-	.get_mctrl	= serial8250_get_mctrl,
-	.stop_tx	= serial8250_stop_tx,
-	.start_tx	= serial8250_start_tx,
-	.throttle	= serial8250_throttle,
-	.unthrottle	= serial8250_unthrottle,
-	.stop_rx	= serial8250_stop_rx,
-	.enable_ms	= serial8250_enable_ms,
-	.break_ctl	= serial8250_break_ctl,
-	.startup	= serial8250_startup,
-	.shutdown	= serial8250_shutdown,
-	.set_termios	= serial8250_set_termios,
-	.set_ldisc	= serial8250_set_ldisc,
-	.pm		= serial8250_pm,
-	.type		= serial8250_type,
-	.release_port	= serial8250_release_port,
-	.request_port	= serial8250_request_port,
-	.config_port	= serial8250_config_port,
-	.verify_port	= serial8250_verify_port,
-#ifdef CONFIG_CONSOLE_POLL
-	.poll_get_char = serial8250_get_poll_char,
-	.poll_put_char = serial8250_put_poll_char,
-#endif
-};
 
 static const struct uart_ops *base_ops;
 static struct uart_ops univ8250_port_ops;
···
 	serial8250_isa_config = v;
 }
 EXPORT_SYMBOL(serial8250_set_isa_configurator);
-
-static void serial8250_init_port(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-
-	spin_lock_init(&port->lock);
-	port->ops = &serial8250_pops;
-
-	up->cur_iotype = 0xFF;
-}
-
-static void serial8250_set_defaults(struct uart_8250_port *up)
-{
-	struct uart_port *port = &up->port;
-
-	if (up->port.flags & UPF_FIXED_TYPE) {
-		unsigned int type = up->port.type;
-
-		if (!up->port.fifosize)
-			up->port.fifosize = uart_config[type].fifo_size;
-		if (!up->tx_loadsz)
-			up->tx_loadsz = uart_config[type].tx_loadsz;
-		if (!up->capabilities)
-			up->capabilities = uart_config[type].flags;
-	}
-
-	set_io_from_upio(port);
-
-	/* default dma handlers */
-	if (up->dma) {
-		if (!up->dma->tx_dma)
-			up->dma->tx_dma = serial8250_tx_dma;
-		if (!up->dma->rx_dma)
-			up->dma->rx_dma = serial8250_rx_dma;
-	}
-}
 
 #ifdef CONFIG_SERIAL_8250_RSA
 
···
 
 #ifdef CONFIG_SERIAL_8250_CONSOLE
 
-static void serial8250_console_putchar(struct uart_port *port, int ch)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	wait_for_xmitr(up, UART_LSR_THRE);
-	serial_port_out(port, UART_TX, ch);
-}
-
-/*
- *	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 serial8250_console_write(struct uart_8250_port *up, const char *s,
-				     unsigned int count)
-{
-	struct uart_port *port = &up->port;
-	unsigned long flags;
-	unsigned int ier;
-	int locked = 1;
-
-	touch_nmi_watchdog();
-
-	serial8250_rpm_get(up);
-
-	if (port->sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = spin_trylock_irqsave(&port->lock, flags);
-	else
-		spin_lock_irqsave(&port->lock, flags);
-
-	/*
-	 *	First save the IER then disable the interrupts
-	 */
-	ier = serial_port_in(port, UART_IER);
-
-	if (up->capabilities & UART_CAP_UUE)
-		serial_port_out(port, UART_IER, UART_IER_UUE);
-	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);
-
-	/*
-	 *	Finally, wait for transmitter to become empty
-	 *	and restore the IER
-	 */
-	wait_for_xmitr(up, BOTH_EMPTY);
-	serial_port_out(port, UART_IER, ier);
-
-	/*
-	 *	The receive handling will happen properly because the
-	 *	receive ready bit will still be set; it is not cleared
-	 *	on read.  However, modem control will not, we must
-	 *	call it if we have saved something in the saved flags
-	 *	while processing with interrupts off.
-	 */
-	if (up->msr_saved_flags)
-		serial8250_modem_status(up);
-
-	if (locked)
-		spin_unlock_irqrestore(&port->lock, flags);
-	serial8250_rpm_put(up);
-}
-
 static void univ8250_console_write(struct console *co, const char *s,
 				   unsigned int count)
 {
 	struct uart_8250_port *up = &serial8250_ports[co->index];
 
 	serial8250_console_write(up, s, count);
-}
-
-static unsigned int probe_baud(struct uart_port *port)
-{
-	unsigned char lcr, dll, dlm;
-	unsigned int quot;
-
-	lcr = serial_port_in(port, UART_LCR);
-	serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);
-	dll = serial_port_in(port, UART_DLL);
-	dlm = serial_port_in(port, UART_DLM);
-	serial_port_out(port, UART_LCR, lcr);
-
-	quot = (dlm << 8) | dll;
-	return (port->uartclk / 16) / quot;
-}
-
-static int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
-{
-	int baud = 9600;
-	int bits = 8;
-	int parity = 'n';
-	int flow = 'n';
-
-	if (!port->iobase && !port->membase)
-		return -ENODEV;
-
-	if (options)
-		uart_parse_options(options, &baud, &parity, &bits, &flow);
-	else if (probe)
-		baud = probe_baud(port);
-
-	return uart_set_options(port, port->cons, baud, parity, bits, flow);
 }
 
 static int univ8250_console_setup(struct console *co, char *options)

drivers/tty/serial/8250/8250_port.c

···
+/*
+ *  Base port operations for 8250/16550-type serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *  Split from 8250_core.c, Copyright (C) 2001 Russell King.
+ *
+ * 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.
+ *
+ * A note about mapbase / membase
+ *
+ *  mapbase is the physical address of the IO port.
+ *  membase is an 'ioremapped' cookie.
+ */
+
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/ratelimit.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/nmi.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include "8250.h"
+
+/*
+ * Debugging.
+ */
+#if 0
+#define DEBUG_AUTOCONF(fmt...)	printk(fmt)
+#else
+#define DEBUG_AUTOCONF(fmt...)	do { } while (0)
+#endif
+
+#define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)
+
+/*
+ * Here we define the default xmit fifo size used for each type of UART.
+ */
+static const struct serial8250_config uart_config[] = {
+	[PORT_UNKNOWN] = {
+		.name		= "unknown",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_8250] = {
+		.name		= "8250",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16450] = {
+		.name		= "16450",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16550] = {
+		.name		= "16550",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16550A] = {
+		.name		= "16550A",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_CIRRUS] = {
+		.name		= "Cirrus",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16650] = {
+		.name		= "ST16650",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_16650V2] = {
+		.name		= "ST16650V2",
+		.fifo_size	= 32,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
+				  UART_FCR_T_TRIG_00,
+		.rxtrig_bytes	= {8, 16, 24, 28},
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_16750] = {
+		.name		= "TI16750",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
+				  UART_FCR7_64BYTE,
+		.rxtrig_bytes	= {1, 16, 32, 56},
+		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP | UART_CAP_AFE,
+	},
+	[PORT_STARTECH] = {
+		.name		= "Startech",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1,
+	},
+	[PORT_16C950] = {
+		.name		= "16C950/954",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		/* UART_CAP_EFR breaks billionon CF bluetooth card. */
+		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
+	},
+	[PORT_16654] = {
+		.name		= "ST16654",
+		.fifo_size	= 64,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
+				  UART_FCR_T_TRIG_10,
+		.rxtrig_bytes	= {8, 16, 56, 60},
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_16850] = {
+		.name		= "XR16850",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
+	},
+	[PORT_RSA] = {
+		.name		= "RSA",
+		.fifo_size	= 2048,
+		.tx_loadsz	= 2048,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_NS16550A] = {
+		.name		= "NS16550A",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_NATSEMI,
+	},
+	[PORT_XSCALE] = {
+		.name		= "XScale",
+		.fifo_size	= 32,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_UUE | UART_CAP_RTOIE,
+	},
+	[PORT_OCTEON] = {
+		.name		= "OCTEON",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_AR7] = {
+		.name		= "AR7",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_U6_16550A] = {
+		.name		= "U6_16550A",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_TEGRA] = {
+		.name		= "Tegra",
+		.fifo_size	= 32,
+		.tx_loadsz	= 8,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 |
+				  UART_FCR_T_TRIG_01,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO | UART_CAP_RTOIE,
+	},
+	[PORT_XR17D15X] = {
+		.name		= "XR17D15X",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
+				  UART_CAP_SLEEP,
+	},
+	[PORT_XR17V35X] = {
+		.name		= "XR17V35X",
+		.fifo_size	= 256,
+		.tx_loadsz	= 256,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_11 |
+				  UART_FCR_T_TRIG_11,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE | UART_CAP_EFR |
+				  UART_CAP_SLEEP,
+	},
+	[PORT_LPC3220] = {
+		.name		= "LPC3220",
+		.fifo_size	= 64,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_DMA_SELECT | UART_FCR_ENABLE_FIFO |
+				  UART_FCR_R_TRIG_00 | UART_FCR_T_TRIG_00,
+		.flags		= UART_CAP_FIFO,
+	},
+	[PORT_BRCM_TRUMANAGE] = {
+		.name		= "TruManage",
+		.fifo_size	= 1,
+		.tx_loadsz	= 1024,
+		.flags		= UART_CAP_HFIFO,
+	},
+	[PORT_8250_CIR] = {
+		.name		= "CIR port"
+	},
+	[PORT_ALTR_16550_F32] = {
+		.name		= "Altera 16550 FIFO32",
+		.fifo_size	= 32,
+		.tx_loadsz	= 32,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_ALTR_16550_F64] = {
+		.name		= "Altera 16550 FIFO64",
+		.fifo_size	= 64,
+		.tx_loadsz	= 64,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+	},
+	[PORT_ALTR_16550_F128] = {
+		.name		= "Altera 16550 FIFO128",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.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 */
+static int default_serial_dl_read(struct uart_8250_port *up)
+{
+	return serial_in(up, UART_DLL) | serial_in(up, UART_DLM) << 8;
+}
+
+/* Uart divisor latch write */
+static void default_serial_dl_write(struct uart_8250_port *up, int value)
+{
+	serial_out(up, UART_DLL, value & 0xff);
+	serial_out(up, UART_DLM, value >> 8 & 0xff);
+}
+
+#if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
+
+/* Au1x00/RT288x UART hardware has a weird register layout */
+static const s8 au_io_in_map[8] = {
+	 0,	/* UART_RX  */
+	 2,	/* UART_IER */
+	 3,	/* UART_IIR */
+	 5,	/* UART_LCR */
+	 6,	/* UART_MCR */
+	 7,	/* UART_LSR */
+	 8,	/* UART_MSR */
+	-1,	/* UART_SCR (unmapped) */
+};
+
+static const s8 au_io_out_map[8] = {
+	 1,	/* UART_TX  */
+	 2,	/* UART_IER */
+	 4,	/* UART_FCR */
+	 5,	/* UART_LCR */
+	 6,	/* UART_MCR */
+	-1,	/* UART_LSR (unmapped) */
+	-1,	/* UART_MSR (unmapped) */
+	-1,	/* UART_SCR (unmapped) */
+};
+
+static unsigned int au_serial_in(struct uart_port *p, int offset)
+{
+	if (offset >= ARRAY_SIZE(au_io_in_map))
+		return UINT_MAX;
+	offset = au_io_in_map[offset];
+	if (offset < 0)
+		return UINT_MAX;
+	return __raw_readl(p->membase + (offset << p->regshift));
+}
+
+static void au_serial_out(struct uart_port *p, int offset, int value)
+{
+	if (offset >= ARRAY_SIZE(au_io_out_map))
+		return;
+	offset = au_io_out_map[offset];
+	if (offset < 0)
+		return;
+	__raw_writel(value, p->membase + (offset << p->regshift));
+}
+
+/* Au1x00 haven't got a standard divisor latch */
+static int au_serial_dl_read(struct uart_8250_port *up)
+{
+	return __raw_readl(up->port.membase + 0x28);
+}
+
+static void au_serial_dl_write(struct uart_8250_port *up, int value)
+{
+	__raw_writel(value, up->port.membase + 0x28);
+}
+
+#endif
+
+static unsigned int hub6_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	outb(p->hub6 - 1 + offset, p->iobase);
+	return inb(p->iobase + 1);
+}
+
+static void hub6_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	outb(p->hub6 - 1 + offset, p->iobase);
+	outb(value, p->iobase + 1);
+}
+
+static unsigned int mem_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return readb(p->membase + offset);
+}
+
+static void mem_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	writeb(value, p->membase + offset);
+}
+
+static void mem32_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	writel(value, p->membase + offset);
+}
+
+static unsigned int mem32_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return readl(p->membase + offset);
+}
+
+static void mem32be_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	iowrite32be(value, p->membase + offset);
+}
+
+static unsigned int mem32be_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return ioread32be(p->membase + offset);
+}
+
+static unsigned int io_serial_in(struct uart_port *p, int offset)
+{
+	offset = offset << p->regshift;
+	return inb(p->iobase + offset);
+}
+
+static void io_serial_out(struct uart_port *p, int offset, int value)
+{
+	offset = offset << p->regshift;
+	outb(value, p->iobase + offset);
+}
+
+static int serial8250_default_handle_irq(struct uart_port *port);
+static int exar_handle_irq(struct uart_port *port);
+
+static void set_io_from_upio(struct uart_port *p)
+{
+	struct uart_8250_port *up = up_to_u8250p(p);
+
+	up->dl_read = default_serial_dl_read;
+	up->dl_write = default_serial_dl_write;
+
+	switch (p->iotype) {
+	case UPIO_HUB6:
+		p->serial_in = hub6_serial_in;
+		p->serial_out = hub6_serial_out;
+		break;
+
+	case UPIO_MEM:
+		p->serial_in = mem_serial_in;
+		p->serial_out = mem_serial_out;
+		break;
+
+	case UPIO_MEM32:
+		p->serial_in = mem32_serial_in;
+		p->serial_out = mem32_serial_out;
+		break;
+
+	case UPIO_MEM32BE:
+		p->serial_in = mem32be_serial_in;
+		p->serial_out = mem32be_serial_out;
+		break;
+
+#if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
+	case UPIO_AU:
+		p->serial_in = au_serial_in;
+		p->serial_out = au_serial_out;
+		up->dl_read = au_serial_dl_read;
+		up->dl_write = au_serial_dl_write;
+		break;
+#endif
+
+	default:
+		p->serial_in = io_serial_in;
+		p->serial_out = io_serial_out;
+		break;
+	}
+	/* Remember loaded iotype */
+	up->cur_iotype = p->iotype;
+	p->handle_irq = serial8250_default_handle_irq;
+}
+
+static void
+serial_port_out_sync(struct uart_port *p, int offset, int value)
+{
+	switch (p->iotype) {
+	case UPIO_MEM:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_AU:
+		p->serial_out(p, offset, value);
+		p->serial_in(p, UART_LCR);	/* safe, no side-effects */
+		break;
+	default:
+		p->serial_out(p, offset, value);
+	}
+}
+
+/*
+ * For the 16C950
+ */
+static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
+{
+	serial_out(up, UART_SCR, offset);
+	serial_out(up, UART_ICR, value);
+}
+
+static unsigned int serial_icr_read(struct uart_8250_port *up, int offset)
+{
+	unsigned int value;
+
+	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
+	serial_out(up, UART_SCR, offset);
+	value = serial_in(up, UART_ICR);
+	serial_icr_write(up, UART_ACR, up->acr);
+
+	return value;
+}
+
+/*
+ * FIFO support.
+ */
+static void serial8250_clear_fifos(struct uart_8250_port *p)
+{
+	if (p->capabilities & UART_CAP_FIFO) {
+		serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_out(p, UART_FCR, UART_FCR_ENABLE_FIFO |
+			       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+		serial_out(p, UART_FCR, 0);
+	}
+}
+
+void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
+{
+	serial8250_clear_fifos(p);
+	serial_out(p, UART_FCR, p->fcr);
+}
+EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
+
+void serial8250_rpm_get(struct uart_8250_port *p)
+{
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+	pm_runtime_get_sync(p->port.dev);
+}
+EXPORT_SYMBOL_GPL(serial8250_rpm_get);
+
+void serial8250_rpm_put(struct uart_8250_port *p)
+{
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+	pm_runtime_mark_last_busy(p->port.dev);
+	pm_runtime_put_autosuspend(p->port.dev);
+}
+EXPORT_SYMBOL_GPL(serial8250_rpm_put);
+
+/*
+ * These two wrappers ensure that enable_runtime_pm_tx() can be called more than
+ * once and disable_runtime_pm_tx() will still disable RPM because the fifo is
+ * empty and the HW can idle again.
+ */
+static void serial8250_rpm_get_tx(struct uart_8250_port *p)
+{
+	unsigned char rpm_active;
+
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+
+	rpm_active = xchg(&p->rpm_tx_active, 1);
+	if (rpm_active)
+		return;
+	pm_runtime_get_sync(p->port.dev);
+}
+
+static void serial8250_rpm_put_tx(struct uart_8250_port *p)
+{
+	unsigned char rpm_active;
+
+	if (!(p->capabilities & UART_CAP_RPM))
+		return;
+
+	rpm_active = xchg(&p->rpm_tx_active, 0);
+	if (!rpm_active)
+		return;
+	pm_runtime_mark_last_busy(p->port.dev);
+	pm_runtime_put_autosuspend(p->port.dev);
+}
+
+/*
+ * IER sleep support.  UARTs which have EFRs need the "extended
+ * capability" bit enabled.  Note that on XR16C850s, we need to
+ * reset LCR to write to IER.
+ */
+static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
+{
+	unsigned char lcr = 0, efr = 0;
+	/*
+	 * Exar UARTs have a SLEEP register that enables or disables
+	 * each UART to enter sleep mode separately.  On the XR17V35x the
+	 * register is accessible to each UART at the UART_EXAR_SLEEP
+	 * offset but the UART channel may only write to the corresponding
+	 * bit.
+	 */
+	serial8250_rpm_get(p);
+	if ((p->port.type == PORT_XR17V35X) ||
+	   (p->port.type == PORT_XR17D15X)) {
+		serial_out(p, UART_EXAR_SLEEP, sleep ? 0xff : 0);
+		goto out;
+	}
+
+	if (p->capabilities & UART_CAP_SLEEP) {
+		if (p->capabilities & UART_CAP_EFR) {
+			lcr = serial_in(p, UART_LCR);
+			efr = serial_in(p, UART_EFR);
+			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
+			serial_out(p, UART_EFR, UART_EFR_ECB);
+			serial_out(p, UART_LCR, 0);
+		}
+		serial_out(p, UART_IER, sleep ? UART_IERX_SLEEP : 0);
+		if (p->capabilities & UART_CAP_EFR) {
+			serial_out(p, UART_LCR, UART_LCR_CONF_MODE_B);
+			serial_out(p, UART_EFR, efr);
+			serial_out(p, UART_LCR, lcr);
+		}
+	}
+out:
+	serial8250_rpm_put(p);
+}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+/*
+ * Attempts to turn on the RSA FIFO.  Returns zero on failure.
+ * We set the port uart clock rate if we succeed.
+ */
+static int __enable_rsa(struct uart_8250_port *up)
+{
+	unsigned char mode;
+	int result;
+
+	mode = serial_in(up, UART_RSA_MSR);
+	result = mode & UART_RSA_MSR_FIFO;
+
+	if (!result) {
+		serial_out(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
+		mode = serial_in(up, UART_RSA_MSR);
+		result = mode & UART_RSA_MSR_FIFO;
+	}
+
+	if (result)
+		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;
+
+	return result;
+}
+
+static void enable_rsa(struct uart_8250_port *up)
+{
+	if (up->port.type == PORT_RSA) {
+		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
+			spin_lock_irq(&up->port.lock);
+			__enable_rsa(up);
+			spin_unlock_irq(&up->port.lock);
+		}
+		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
+			serial_out(up, UART_RSA_FRR, 0);
+	}
+}
+
+/*
+ * Attempts to turn off the RSA FIFO.  Returns zero on failure.
+ * It is unknown why interrupts were disabled in here.  However,
+ * the caller is expected to preserve this behaviour by grabbing
+ * the spinlock before calling this function.
+ */
+static void disable_rsa(struct uart_8250_port *up)
+{
+	unsigned char mode;
+	int result;
+
+	if (up->port.type == PORT_RSA &&
+	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
+		spin_lock_irq(&up->port.lock);
+
+		mode = serial_in(up, UART_RSA_MSR);
+		result = !(mode & UART_RSA_MSR_FIFO);
+
+		if (!result) {
+			serial_out(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
+			mode = serial_in(up, UART_RSA_MSR);
+			result = !(mode & UART_RSA_MSR_FIFO);
+		}
+
+		if (result)
+			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
+		spin_unlock_irq(&up->port.lock);
+	}
+}
+#endif /* CONFIG_SERIAL_8250_RSA */
+
+/*
+ * This is a quickie test to see how big the FIFO is.
+ * It doesn't work at all the time, more's the pity.
+ */
+static int size_fifo(struct uart_8250_port *up)
+{
+	unsigned char old_fcr, old_mcr, old_lcr;
+	unsigned short old_dl;
+	int count;
+
+	old_lcr = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, 0);
+	old_fcr = serial_in(up, UART_FCR);
+	old_mcr = serial_in(up, UART_MCR);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+		    UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_MCR, UART_MCR_LOOP);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	old_dl = serial_dl_read(up);
+	serial_dl_write(up, 0x0001);
+	serial_out(up, UART_LCR, 0x03);
+	for (count = 0; count < 256; count++)
+		serial_out(up, UART_TX, count);
+	mdelay(20);/* FIXME - schedule_timeout */
+	for (count = 0; (serial_in(up, UART_LSR) & UART_LSR_DR) &&
+	     (count < 256); count++)
+		serial_in(up, UART_RX);
+	serial_out(up, UART_FCR, old_fcr);
+	serial_out(up, UART_MCR, old_mcr);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_dl_write(up, old_dl);
+	serial_out(up, UART_LCR, old_lcr);
+
+	return count;
+}
+
+/*
+ * Read UART ID using the divisor method - set DLL and DLM to zero
+ * and the revision will be in DLL and device type in DLM.  We
+ * preserve the device state across this.
+ */
+static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
+{
+	unsigned char old_dll, old_dlm, old_lcr;
+	unsigned int id;
+
+	old_lcr = serial_in(p, UART_LCR);
+	serial_out(p, UART_LCR, UART_LCR_CONF_MODE_A);
+
+	old_dll = serial_in(p, UART_DLL);
+	old_dlm = serial_in(p, UART_DLM);
+
+	serial_out(p, UART_DLL, 0);
+	serial_out(p, UART_DLM, 0);
+
+	id = serial_in(p, UART_DLL) | serial_in(p, UART_DLM) << 8;
+
+	serial_out(p, UART_DLL, old_dll);
+	serial_out(p, UART_DLM, old_dlm);
+	serial_out(p, UART_LCR, old_lcr);
+
+	return id;
+}
+
+/*
+ * This is a helper routine to autodetect StarTech/Exar/Oxsemi UART's.
+ * When this function is called we know it is at least a StarTech
+ * 16650 V2, but it might be one of several StarTech UARTs, or one of
+ * its clones.  (We treat the broken original StarTech 16650 V1 as a
+ * 16550, and why not?  Startech doesn't seem to even acknowledge its
+ * existence.)
+ *
+ * What evil have men's minds wrought...
+ */
+static void autoconfig_has_efr(struct uart_8250_port *up)
+{
+	unsigned int id1, id2, id3, rev;
+
+	/*
+	 * Everything with an EFR has SLEEP
+	 */
+	up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
+
+	/*
+	 * First we check to see if it's an Oxford Semiconductor UART.
+	 *
+	 * If we have to do this here because some non-National
+	 * Semiconductor clone chips lock up if you try writing to the
+	 * LSR register (which serial_icr_read does)
+	 */
+
+	/*
+	 * Check for Oxford Semiconductor 16C950.
+	 *
+	 * EFR [4] must be set else this test fails.
+	 *
+	 * This shouldn't be necessary, but Mike Hudson ([e-mail])
+	 * claims that it's needed for 952 dual UART's (which are not
+	 * recommended for new designs).
+	 */
+	up->acr = 0;
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, UART_EFR_ECB);
+	serial_out(up, UART_LCR, 0x00);
+	id1 = serial_icr_read(up, UART_ID1);
+	id2 = serial_icr_read(up, UART_ID2);
+	id3 = serial_icr_read(up, UART_ID3);
+	rev = serial_icr_read(up, UART_REV);
+
+	DEBUG_AUTOCONF("950id=%02x:%02x:%02x:%02x ", id1, id2, id3, rev);
+
+	if (id1 == 0x16 && id2 == 0xC9 &&
+	    (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
+		up->port.type = PORT_16C950;
+
+		/*
+		 * Enable work around for the Oxford Semiconductor 952 rev B
+		 * chip which causes it to seriously miscalculate baud rates
+		 * when DLL is 0.
+		 */
+		if (id3 == 0x52 && rev == 0x01)
+			up->bugs |= UART_BUG_QUOT;
+		return;
+	}
+
+	/*
+	 * We check for a XR16C850 by setting DLL and DLM to 0, and then
+	 * reading back DLL and DLM.  The chip type depends on the DLM
+	 * value read back:
+	 *  0x10 - XR16C850 and the DLL contains the chip revision.
+	 *  0x12 - XR16C2850.
+	 *  0x14 - XR16C854.
+	 */
+	id1 = autoconfig_read_divisor_id(up);
+	DEBUG_AUTOCONF("850id=%04x ", id1);
+
+	id2 = id1 >> 8;
+	if (id2 == 0x10 || id2 == 0x12 || id2 == 0x14) {
+		up->port.type = PORT_16850;
+		return;
+	}
+
+	/*
+	 * It wasn't an XR16C850.
+	 *
+	 * We distinguish between the '654 and the '650 by counting
+	 * how many bytes are in the FIFO.  I'm using this for now,
+	 * since that's the technique that was sent to me in the
+	 * serial driver update, but I'm not convinced this works.
+	 * I've had problems doing this in the past.  -TYT
+	 */
+	if (size_fifo(up) == 64)
+		up->port.type = PORT_16654;
+	else
+		up->port.type = PORT_16650V2;
+}
+
+/*
+ * We detected a chip without a FIFO.  Only two fall into
+ * this category - the original 8250 and the 16450.  The
+ * 16450 has a scratch register (accessible with LCR=0)
+ */
+static void autoconfig_8250(struct uart_8250_port *up)
+{
+	unsigned char scratch, status1, status2;
+
+	up->port.type = PORT_8250;
+
+	scratch = serial_in(up, UART_SCR);
+	serial_out(up, UART_SCR, 0xa5);
+	status1 = serial_in(up, UART_SCR);
+	serial_out(up, UART_SCR, 0x5a);
+	status2 = serial_in(up, UART_SCR);
+	serial_out(up, UART_SCR, scratch);
+
+	if (status1 == 0xa5 && status2 == 0x5a)
+		up->port.type = PORT_16450;
+}
+
+static int broken_efr(struct uart_8250_port *up)
+{
+	/*
+	 * Exar ST16C2550 "A2" devices incorrectly detect as
+	 * having an EFR, and report an ID of 0x0201.  See
+	 * http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/4812.html
+	 */
+	if (autoconfig_read_divisor_id(up) == 0x0201 && size_fifo(up) == 16)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * We know that the chip has FIFOs.  Does it have an EFR?  The
+ * EFR is located in the same register position as the IIR and
+ * we know the top two bits of the IIR are currently set.  The
+ * EFR should contain zero.  Try to read the EFR.
+ */
+static void autoconfig_16550a(struct uart_8250_port *up)
+{
+	unsigned char status1, status2;
+	unsigned int iersave;
+
+	up->port.type = PORT_16550A;
+	up->capabilities |= UART_CAP_FIFO;
+
+	/*
+	 * XR17V35x UARTs have an extra divisor register, DLD
+	 * that gets enabled with when DLAB is set which will
+	 * cause the device to incorrectly match and assign
+	 * port type to PORT_16650.  The EFR for this UART is
+	 * found at offset 0x09. Instead check the Deice ID (DVID)
+	 * register for a 2, 4 or 8 port UART.
+	 */
+	if (up->port.flags & UPF_EXAR_EFR) {
+		status1 = serial_in(up, UART_EXAR_DVID);
+		if (status1 == 0x82 || status1 == 0x84 || status1 == 0x88) {
+			DEBUG_AUTOCONF("Exar XR17V35x ");
+			up->port.type = PORT_XR17V35X;
+			up->capabilities |= UART_CAP_AFE | UART_CAP_EFR |
+						UART_CAP_SLEEP;
+
+			return;
+		}
+
+	}
+
+	/*
+	 * Check for presence of the EFR when DLAB is set.
+	 * Only ST16C650V1 UARTs pass this test.
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	if (serial_in(up, UART_EFR) == 0) {
+		serial_out(up, UART_EFR, 0xA8);
+		if (serial_in(up, UART_EFR) != 0) {
+			DEBUG_AUTOCONF("EFRv1 ");
+			up->port.type = PORT_16650;
+			up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP;
+		} else {
+			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;
+	}
+
+	/*
+	 * Maybe it requires 0xbf to be written to the LCR.
+	 * (other ST16C650V2 UARTs, TI16C752A, etc)
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	if (serial_in(up, UART_EFR) == 0 && !broken_efr(up)) {
+		DEBUG_AUTOCONF("EFRv2 ");
+		autoconfig_has_efr(up);
+		return;
+	}
+
+	/*
+	 * Check for a National Semiconductor SuperIO chip.
+	 * Attempt to switch to bank 2, read the value of the LOOP bit
+	 * from EXCR1. Switch back to bank 0, change it in MCR. Then
+	 * switch back to bank 2, read it from EXCR1 again and check
+	 * it's changed. If so, set baud_base in EXCR2 to 921600. -- dwmw2
+	 */
+	serial_out(up, UART_LCR, 0);
+	status1 = serial_in(up, UART_MCR);
+	serial_out(up, UART_LCR, 0xE0);
+	status2 = serial_in(up, 0x02); /* EXCR1 */
+
+	if (!((status2 ^ status1) & UART_MCR_LOOP)) {
+		serial_out(up, UART_LCR, 0);
+		serial_out(up, UART_MCR, status1 ^ UART_MCR_LOOP);
+		serial_out(up, UART_LCR, 0xE0);
+		status2 = serial_in(up, 0x02); /* EXCR1 */
+		serial_out(up, UART_LCR, 0);
+		serial_out(up, UART_MCR, status1);
+
+		if ((status2 ^ status1) & UART_MCR_LOOP) {
+			unsigned short quot;
+
+			serial_out(up, UART_LCR, 0xE0);
+
+			quot = serial_dl_read(up);
+			quot <<= 3;
+
+			if (ns16550a_goto_highspeed(up))
+				serial_dl_write(up, quot);
+
+			serial_out(up, UART_LCR, 0);
+
+			up->port.uartclk = 921600*16;
+			up->port.type = PORT_NS16550A;
+			up->capabilities |= UART_NATSEMI;
+			return;
+		}
+	}
+
+	/*
+	 * No EFR.  Try to detect a TI16750, which only sets bit 5 of
+	 * the IIR when 64 byte FIFO mode is enabled when DLAB is set.
+	 * Try setting it with and without DLAB set.  Cheap clones
+	 * set bit 5 without DLAB set.
+	 */
+	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, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
+	status2 = serial_in(up, UART_IIR) >> 5;
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_LCR, 0);
+
+	DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
+
+	if (status1 == 6 && status2 == 7) {
+		up->port.type = PORT_16750;
+		up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
+		return;
+	}
+
+	/*
+	 * Try writing and reading the UART_IER_UUE bit (b6).
+	 * If it works, this is probably one of the Xscale platform's
+	 * internal UARTs.
+	 * We're going to explicitly set the UUE bit to 0 before
+	 * trying to write and read a 1 just to make sure it's not
+	 * already a 1 and maybe locked there before we even start start.
+	 */
+	iersave = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, iersave & ~UART_IER_UUE);
+	if (!(serial_in(up, UART_IER) & UART_IER_UUE)) {
+		/*
+		 * OK it's in a known zero state, try writing and reading
+		 * without disturbing the current state of the other bits.
+		 */
+		serial_out(up, UART_IER, iersave | UART_IER_UUE);
+		if (serial_in(up, UART_IER) & UART_IER_UUE) {
+			/*
+			 * It's an Xscale.
+			 * We'll leave the UART_IER_UUE bit set to 1 (enabled).
+			 */
+			DEBUG_AUTOCONF("Xscale ");
+			up->port.type = PORT_XSCALE;
+			up->capabilities |= UART_CAP_UUE | UART_CAP_RTOIE;
+			return;
+		}
+	} else {
+		/*
+		 * If we got here we couldn't force the IER_UUE bit to 0.
+		 * Log it and continue.
+		 */
+		DEBUG_AUTOCONF("Couldn't force IER_UUE to 0 ");
+	}
+	serial_out(up, UART_IER, iersave);
+
+	/*
+	 * Exar uarts have EFR in a weird location
+	 */
+	if (up->port.flags & UPF_EXAR_EFR) {
+		DEBUG_AUTOCONF("Exar XR17D15x ");
+		up->port.type = PORT_XR17D15X;
+		up->capabilities |= UART_CAP_AFE | UART_CAP_EFR |
+				    UART_CAP_SLEEP;
+
+		return;
+	}
+
+	/*
+	 * We distinguish between 16550A and U6 16550A by counting
+	 * how many bytes are in the FIFO.
+	 */
+	if (up->port.type == PORT_16550A && size_fifo(up) == 64) {
+		up->port.type = PORT_U6_16550A;
+		up->capabilities |= UART_CAP_AFE;
+	}
+}
+
+/*
+ * This routine is called by rs_init() to initialize a specific serial
+ * port.  It determines what type of UART chip this serial port is
+ * using: 8250, 16450, 16550, 16550A.  The important question is
+ * whether or not this UART is a 16550A or not, since this will
+ * determine whether or not we can use its FIFO features or not.
+ */
+static void autoconfig(struct uart_8250_port *up)
+{
+	unsigned char status1, scratch, scratch2, scratch3;
+	unsigned char save_lcr, save_mcr;
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int old_capabilities;
+
+	if (!port->iobase && !port->mapbase && !port->membase)
+		return;
+
+	DEBUG_AUTOCONF("ttyS%d: autoconf (0x%04lx, 0x%p): ",
+		       serial_index(port), port->iobase, port->membase);
+
+	/*
+	 * We really do need global IRQs disabled here - we're going to
+	 * be frobbing the chips IRQ enable register to see if it exists.
+	 */
+	spin_lock_irqsave(&port->lock, flags);
+
+	up->capabilities = 0;
+	up->bugs = 0;
+
+	if (!(port->flags & UPF_BUGGY_UART)) {
+		/*
+		 * Do a simple existence test first; if we fail this,
+		 * there's no point trying anything else.
+		 *
+		 * 0x80 is used as a nonsense port to prevent against
+		 * false positives due to ISA bus float.  The
+		 * assumption is that 0x80 is a non-existent port;
+		 * which should be safe since include/asm/io.h also
+		 * makes this assumption.
+		 *
+		 * Note: this is safe as long as MCR bit 4 is clear
+		 * and the device is in "PC" mode.
+		 */
+		scratch = serial_in(up, UART_IER);
+		serial_out(up, UART_IER, 0);
+#ifdef __i386__
+		outb(0xff, 0x080);
+#endif
+		/*
+		 * Mask out IER[7:4] bits for test as some UARTs (e.g. TL
+		 * 16C754B) allow only to modify them if an EFR bit is set.
+		 */
+		scratch2 = serial_in(up, UART_IER) & 0x0f;
+		serial_out(up, UART_IER, 0x0F);
+#ifdef __i386__
+		outb(0, 0x080);
+#endif
+		scratch3 = serial_in(up, UART_IER) & 0x0f;
+		serial_out(up, UART_IER, scratch);
+		if (scratch2 != 0 || scratch3 != 0x0F) {
+			/*
+			 * We failed; there's nothing here
+			 */
+			spin_unlock_irqrestore(&port->lock, flags);
+			DEBUG_AUTOCONF("IER test failed (%02x, %02x) ",
+				       scratch2, scratch3);
+			goto out;
+		}
+	}
+
+	save_mcr = serial_in(up, UART_MCR);
+	save_lcr = serial_in(up, UART_LCR);
+
+	/*
+	 * Check to see if a UART is really there.  Certain broken
+	 * internal modems based on the Rockwell chipset fail this
+	 * test, because they apparently don't implement the loopback
+	 * test mode.  So this test is skipped on the COM 1 through
+	 * COM 4 ports.  This *should* be safe, since no board
+	 * manufacturer would be stupid enough to design a board
+	 * that conflicts with COM 1-4 --- we hope!
+	 */
+	if (!(port->flags & UPF_SKIP_TEST)) {
+		serial_out(up, UART_MCR, UART_MCR_LOOP | 0x0A);
+		status1 = serial_in(up, UART_MSR) & 0xF0;
+		serial_out(up, UART_MCR, save_mcr);
+		if (status1 != 0x90) {
+			spin_unlock_irqrestore(&port->lock, flags);
+			DEBUG_AUTOCONF("LOOP test failed (%02x) ",
+				       status1);
+			goto out;
+		}
+	}
+
+	/*
+	 * We're pretty sure there's a port here.  Lets find out what
+	 * type of port it is.  The IIR top two bits allows us to find
+	 * out if it's 8250 or 16450, 16550, 16550A or later.  This
+	 * determines what we test for next.
+	 *
+	 * We also initialise the EFR (if any) to zero for later.  The
+	 * EFR occupies the same register location as the FCR and IIR.
+	 */
+	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+	serial_out(up, UART_EFR, 0);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	scratch = serial_in(up, UART_IIR) >> 6;
+
+	switch (scratch) {
+	case 0:
+		autoconfig_8250(up);
+		break;
+	case 1:
+		port->type = PORT_UNKNOWN;
+		break;
+	case 2:
+		port->type = PORT_16550;
+		break;
+	case 3:
+		autoconfig_16550a(up);
+		break;
+	}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * Only probe for RSA ports if we got the region.
+	 */
+	if (port->type == PORT_16550A && up->probe & UART_PROBE_RSA &&
+	    __enable_rsa(up))
+		port->type = PORT_RSA;
+#endif
+
+	serial_out(up, UART_LCR, save_lcr);
+
+	port->fifosize = uart_config[up->port.type].fifo_size;
+	old_capabilities = up->capabilities;
+	up->capabilities = uart_config[port->type].flags;
+	up->tx_loadsz = uart_config[port->type].tx_loadsz;
+
+	if (port->type == PORT_UNKNOWN)
+		goto out_lock;
+
+	/*
+	 * Reset the UART.
+	 */
+#ifdef CONFIG_SERIAL_8250_RSA
+	if (port->type == PORT_RSA)
+		serial_out(up, UART_RSA_FRR, 0);
+#endif
+	serial_out(up, UART_MCR, save_mcr);
+	serial8250_clear_fifos(up);
+	serial_in(up, UART_RX);
+	if (up->capabilities & UART_CAP_UUE)
+		serial_out(up, UART_IER, UART_IER_UUE);
+	else
+		serial_out(up, UART_IER, 0);
+
+out_lock:
+	spin_unlock_irqrestore(&port->lock, flags);
+	if (up->capabilities != old_capabilities) {
+		printk(KERN_WARNING
+		       "ttyS%d: detected caps %08x should be %08x\n",
+		       serial_index(port), old_capabilities,
+		       up->capabilities);
+	}
+out:
+	DEBUG_AUTOCONF("iir=%d ", scratch);
+	DEBUG_AUTOCONF("type=%s\n", uart_config[port->type].name);
+}
+
+static void autoconfig_irq(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	unsigned char save_mcr, save_ier;
+	unsigned char save_ICP = 0;
+	unsigned int ICP = 0;
+	unsigned long irqs;
+	int irq;
+
+	if (port->flags & UPF_FOURPORT) {
+		ICP = (port->iobase & 0xfe0) | 0x1f;
+		save_ICP = inb_p(ICP);
+		outb_p(0x80, ICP);
+		inb_p(ICP);
+	}
+
+	/* forget possible initially masked and pending IRQ */
+	probe_irq_off(probe_irq_on());
+	save_mcr = serial_in(up, UART_MCR);
+	save_ier = serial_in(up, UART_IER);
+	serial_out(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
+
+	irqs = probe_irq_on();
+	serial_out(up, UART_MCR, 0);
+	udelay(10);
+	if (port->flags & UPF_FOURPORT) {
+		serial_out(up, UART_MCR,
+			    UART_MCR_DTR | UART_MCR_RTS);
+	} else {
+		serial_out(up, UART_MCR,
+			    UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
+	}
+	serial_out(up, UART_IER, 0x0f);	/* enable all intrs */
+	serial_in(up, UART_LSR);
+	serial_in(up, UART_RX);
+	serial_in(up, UART_IIR);
+	serial_in(up, UART_MSR);
+	serial_out(up, UART_TX, 0xFF);
+	udelay(20);
+	irq = probe_irq_off(irqs);
+
+	serial_out(up, UART_MCR, save_mcr);
+	serial_out(up, UART_IER, save_ier);
+
+	if (port->flags & UPF_FOURPORT)
+		outb_p(save_ICP, ICP);
+
+	port->irq = (irq > 0) ? irq : 0;
+}
+
+static inline void __stop_tx(struct uart_8250_port *p)
+{
+	if (p->ier & UART_IER_THRI) {
+		p->ier &= ~UART_IER_THRI;
+		serial_out(p, UART_IER, p->ier);
+		serial8250_rpm_put_tx(p);
+	}
+}
+
+static void serial8250_stop_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_rpm_get(up);
+	__stop_tx(up);
+
+	/*
+	 * We really want to stop the transmitter from sending.
+	 */
+	if (port->type == PORT_16C950) {
+		up->acr |= UART_ACR_TXDIS;
+		serial_icr_write(up, UART_ACR, up->acr);
+	}
+	serial8250_rpm_put(up);
+}
+
+static void serial8250_start_tx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_rpm_get_tx(up);
+
+	if (up->dma && !up->dma->tx_dma(up))
+		return;
+
+	if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_port_out(port, UART_IER, up->ier);
+
+		if (up->bugs & UART_BUG_TXEN) {
+			unsigned char lsr;
+			lsr = serial_in(up, UART_LSR);
+			up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+			if (lsr & UART_LSR_THRE)
+				serial8250_tx_chars(up);
+		}
+	}
+
+	/*
+	 * Re-enable the transmitter if we disabled it.
+	 */
+	if (port->type == PORT_16C950 && up->acr & UART_ACR_TXDIS) {
+		up->acr &= ~UART_ACR_TXDIS;
+		serial_icr_write(up, UART_ACR, up->acr);
+	}
+}
+
+static void serial8250_throttle(struct uart_port *port)
+{
+	port->throttle(port);
+}
+
+static void serial8250_unthrottle(struct uart_port *port)
+{
+	port->unthrottle(port);
+}
+
+static void serial8250_stop_rx(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_rpm_get(up);
+
+	up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_port_out(port, UART_IER, up->ier);
+
+	serial8250_rpm_put(up);
+}
+
+static void serial8250_disable_ms(struct uart_port *port)
+{
+	struct uart_8250_port *up =
+		container_of(port, struct uart_8250_port, port);
+
+	/* no MSR capabilities */
+	if (up->bugs & UART_BUG_NOMSR)
+		return;
+
+	up->ier &= ~UART_IER_MSI;
+	serial_port_out(port, UART_IER, up->ier);
+}
+
+static void serial8250_enable_ms(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	/* no MSR capabilities */
+	if (up->bugs & UART_BUG_NOMSR)
+		return;
+
+	up->ier |= UART_IER_MSI;
+
+	serial8250_rpm_get(up);
+	serial_port_out(port, UART_IER, up->ier);
+	serial8250_rpm_put(up);
+}
+
+/*
+ * serial8250_rx_chars: processes according to the passed in LSR
+ * value, and returns the remaining LSR bits not handled
+ * by this Rx routine.
+ */
+unsigned char
+serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
+{
+	struct uart_port *port = &up->port;
+	unsigned char ch;
+	int max_count = 256;
+	char flag;
+
+	do {
+		if (likely(lsr & UART_LSR_DR))
+			ch = serial_in(up, UART_RX);
+		else
+			/*
+			 * Intel 82571 has a Serial Over Lan device that will
+			 * set UART_LSR_BI without setting UART_LSR_DR when
+			 * it receives a break. To avoid reading from the
+			 * receive buffer without UART_LSR_DR bit set, we
+			 * just force the read character to be 0
+			 */
+			ch = 0;
+
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		lsr |= up->lsr_saved_flags;
+		up->lsr_saved_flags = 0;
+
+		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
+			if (lsr & UART_LSR_BI) {
+				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
+				port->icount.brk++;
+				/*
+				 * We do the SysRQ and SAK checking
+				 * here because otherwise the break
+				 * may get masked by ignore_status_mask
+				 * or read_status_mask.
+				 */
+				if (uart_handle_break(port))
+					goto ignore_char;
+			} else if (lsr & UART_LSR_PE)
+				port->icount.parity++;
+			else if (lsr & UART_LSR_FE)
+				port->icount.frame++;
+			if (lsr & UART_LSR_OE)
+				port->icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ignored.
+			 */
+			lsr &= port->read_status_mask;
+
+			if (lsr & UART_LSR_BI) {
+				DEBUG_INTR("handling break....");
+				flag = TTY_BREAK;
+			} else if (lsr & UART_LSR_PE)
+				flag = TTY_PARITY;
+			else if (lsr & UART_LSR_FE)
+				flag = TTY_FRAME;
+		}
+		if (uart_handle_sysrq_char(port, ch))
+			goto ignore_char;
+
+		uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
+
+ignore_char:
+		lsr = serial_in(up, UART_LSR);
+	} while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (--max_count > 0));
+	spin_unlock(&port->lock);
+	tty_flip_buffer_push(&port->state->port);
+	spin_lock(&port->lock);
+	return lsr;
+}
+EXPORT_SYMBOL_GPL(serial8250_rx_chars);
+
+void serial8250_tx_chars(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	int count;
+
+	if (port->x_char) {
+		serial_out(up, UART_TX, port->x_char);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+	if (uart_tx_stopped(port)) {
+		serial8250_stop_tx(port);
+		return;
+	}
+	if (uart_circ_empty(xmit)) {
+		__stop_tx(up);
+		return;
+	}
+
+	count = up->tx_loadsz;
+	do {
+		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+		if (up->capabilities & UART_CAP_HFIFO) {
+			if ((serial_port_in(port, UART_LSR) & BOTH_EMPTY) !=
+			    BOTH_EMPTY)
+				break;
+		}
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	DEBUG_INTR("THRE...");
+
+	/*
+	 * With RPM enabled, we have to wait until the FIFO is empty before the
+	 * HW can go idle. So we get here once again with empty FIFO and disable
+	 * the interrupt and RPM in __stop_tx()
+	 */
+	if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
+		__stop_tx(up);
+}
+EXPORT_SYMBOL_GPL(serial8250_tx_chars);
+
+/* Caller holds uart port lock */
+unsigned int serial8250_modem_status(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+	unsigned int status = serial_in(up, UART_MSR);
+
+	status |= up->msr_saved_flags;
+	up->msr_saved_flags = 0;
+	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
+	    port->state != NULL) {
+		if (status & UART_MSR_TERI)
+			port->icount.rng++;
+		if (status & UART_MSR_DDSR)
+			port->icount.dsr++;
+		if (status & UART_MSR_DDCD)
+			uart_handle_dcd_change(port, status & UART_MSR_DCD);
+		if (status & UART_MSR_DCTS)
+			uart_handle_cts_change(port, status & UART_MSR_CTS);
+
+		wake_up_interruptible(&port->state->port.delta_msr_wait);
+	}
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(serial8250_modem_status);
+
+/*
+ * This handles the interrupt from one port.
+ */
+int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
+{
+	unsigned char status;
+	unsigned long flags;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	int dma_err = 0;
+
+	if (iir & UART_IIR_NO_INT)
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	status = serial_port_in(port, UART_LSR);
+
+	DEBUG_INTR("status = %x...", status);
+
+	if (status & (UART_LSR_DR | UART_LSR_BI)) {
+		if (up->dma)
+			dma_err = up->dma->rx_dma(up, iir);
+
+		if (!up->dma || dma_err)
+			status = serial8250_rx_chars(up, status);
+	}
+	serial8250_modem_status(up);
+	if ((!up->dma || (up->dma && up->dma->tx_err)) &&
+	    (status & UART_LSR_THRE))
+		serial8250_tx_chars(up);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	return 1;
+}
+EXPORT_SYMBOL_GPL(serial8250_handle_irq);
+
+static int serial8250_default_handle_irq(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int iir;
+	int ret;
+
+	serial8250_rpm_get(up);
+
+	iir = serial_port_in(port, UART_IIR);
+	ret = serial8250_handle_irq(port, iir);
+
+	serial8250_rpm_put(up);
+	return ret;
+}
+
+/*
+ * These Exar UARTs have an extra interrupt indicator that could
+ * fire for a few unimplemented interrupts.  One of which is a
+ * wakeup event when coming out of sleep.  Put this here just
+ * to be on the safe side that these interrupts don't go unhandled.
+ */
+static int exar_handle_irq(struct uart_port *port)
+{
+	unsigned char int0, int1, int2, int3;
+	unsigned int iir = serial_port_in(port, UART_IIR);
+	int ret;
+
+	ret = serial8250_handle_irq(port, iir);
+
+	if ((port->type == PORT_XR17V35X) ||
+	   (port->type == PORT_XR17D15X)) {
+		int0 = serial_port_in(port, 0x80);
+		int1 = serial_port_in(port, 0x81);
+		int2 = serial_port_in(port, 0x82);
+		int3 = serial_port_in(port, 0x83);
+	}
+
+	return ret;
+}
+
+static unsigned int serial8250_tx_empty(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+	unsigned int lsr;
+
+	serial8250_rpm_get(up);
+
+	spin_lock_irqsave(&port->lock, flags);
+	lsr = serial_port_in(port, UART_LSR);
+	up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS;
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	serial8250_rpm_put(up);
+
+	return (lsr & BOTH_EMPTY) == BOTH_EMPTY ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int serial8250_get_mctrl(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int status;
+	unsigned int ret;
+
+	serial8250_rpm_get(up);
+	status = serial8250_modem_status(up);
+	serial8250_rpm_put(up);
+
+	ret = 0;
+	if (status & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+	if (status & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+	if (status & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+	if (status & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+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;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (mctrl & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	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)
+		port->set_mctrl(port, mctrl);
+	else
+		serial8250_do_set_mctrl(port, mctrl);
+}
+
+static void serial8250_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	serial8250_rpm_get(up);
+	spin_lock_irqsave(&port->lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_port_out(port, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+}
+
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct uart_8250_port *up, int bits)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	for (;;) {
+		status = serial_in(up, UART_LSR);
+
+		up->lsr_saved_flags |= status & LSR_SAVE_FLAGS;
+
+		if ((status & bits) == bits)
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	}
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		unsigned int tmout;
+		for (tmout = 1000000; tmout; tmout--) {
+			unsigned int msr = serial_in(up, UART_MSR);
+			up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
+			if (msr & UART_MSR_CTS)
+				break;
+			udelay(1);
+			touch_nmi_watchdog();
+		}
+	}
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context.
+ */
+
+static int serial8250_get_poll_char(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned char lsr;
+	int status;
+
+	serial8250_rpm_get(up);
+
+	lsr = serial_port_in(port, UART_LSR);
+
+	if (!(lsr & UART_LSR_DR)) {
+		status = NO_POLL_CHAR;
+		goto out;
+	}
+
+	status = serial_port_in(port, UART_RX);
+out:
+	serial8250_rpm_put(up);
+	return status;
+}
+
+
+static void serial8250_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_rpm_get(up);
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_port_in(port, UART_IER);
+	if (up->capabilities & UART_CAP_UUE)
+		serial_port_out(port, UART_IER, UART_IER_UUE);
+	else
+		serial_port_out(port, UART_IER, 0);
+
+	wait_for_xmitr(up, BOTH_EMPTY);
+	/*
+	 *	Send the character out.
+	 */
+	serial_port_out(port, UART_TX, c);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, BOTH_EMPTY);
+	serial_port_out(port, UART_IER, ier);
+	serial8250_rpm_put(up);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+int serial8250_do_startup(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+	unsigned char lsr, iir;
+	int retval;
+
+	if (port->type == PORT_8250_CIR)
+		return -ENODEV;
+
+	if (!port->fifosize)
+		port->fifosize = uart_config[port->type].fifo_size;
+	if (!up->tx_loadsz)
+		up->tx_loadsz = uart_config[port->type].tx_loadsz;
+	if (!up->capabilities)
+		up->capabilities = uart_config[port->type].flags;
+	up->mcr = 0;
+
+	if (port->iotype != up->cur_iotype)
+		set_io_from_upio(port);
+
+	serial8250_rpm_get(up);
+	if (port->type == PORT_16C950) {
+		/* Wake up and initialize UART */
+		up->acr = 0;
+		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_port_out(port, UART_EFR, UART_EFR_ECB);
+		serial_port_out(port, UART_IER, 0);
+		serial_port_out(port, UART_LCR, 0);
+		serial_icr_write(up, UART_CSR, 0); /* Reset the UART */
+		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+		serial_port_out(port, UART_EFR, UART_EFR_ECB);
+		serial_port_out(port, UART_LCR, 0);
+	}
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * If this is an RSA port, see if we can kick it up to the
+	 * higher speed clock.
+	 */
+	enable_rsa(up);
+#endif
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	serial8250_clear_fifos(up);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	serial_port_in(port, UART_LSR);
+	serial_port_in(port, UART_RX);
+	serial_port_in(port, UART_IIR);
+	serial_port_in(port, UART_MSR);
+
+	/*
+	 * At this point, there's no way the LSR could still be 0xff;
+	 * if it is, then bail out, because there's likely no UART
+	 * here.
+	 */
+	if (!(port->flags & UPF_BUGGY_UART) &&
+	    (serial_port_in(port, UART_LSR) == 0xff)) {
+		printk_ratelimited(KERN_INFO "ttyS%d: LSR safety check engaged!\n",
+				   serial_index(port));
+		retval = -ENODEV;
+		goto out;
+	}
+
+	/*
+	 * For a XR16C850, we need to set the trigger levels
+	 */
+	if (port->type == PORT_16850) {
+		unsigned char fctr;
+
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+
+		fctr = serial_in(up, UART_FCTR) & ~(UART_FCTR_RX|UART_FCTR_TX);
+		serial_port_out(port, UART_FCTR,
+				fctr | UART_FCTR_TRGD | UART_FCTR_RX);
+		serial_port_out(port, UART_TRG, UART_TRG_96);
+		serial_port_out(port, UART_FCTR,
+				fctr | UART_FCTR_TRGD | UART_FCTR_TX);
+		serial_port_out(port, UART_TRG, UART_TRG_96);
+
+		serial_port_out(port, UART_LCR, 0);
+	}
+
+	if (port->irq) {
+		unsigned char iir1;
+		/*
+		 * Test for UARTs that do not reassert THRE when the
+		 * transmitter is idle and the interrupt has already
+		 * been cleared.  Real 16550s should always reassert
+		 * this interrupt whenever the transmitter is idle and
+		 * the interrupt is enabled.  Delays are necessary to
+		 * allow register changes to become visible.
+		 */
+		spin_lock_irqsave(&port->lock, flags);
+		if (up->port.irqflags & IRQF_SHARED)
+			disable_irq_nosync(port->irq);
+
+		wait_for_xmitr(up, UART_LSR_THRE);
+		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
+		udelay(1); /* allow THRE to set */
+		iir1 = serial_port_in(port, UART_IIR);
+		serial_port_out(port, UART_IER, 0);
+		serial_port_out_sync(port, UART_IER, UART_IER_THRI);
+		udelay(1); /* allow a working UART time to re-assert THRE */
+		iir = serial_port_in(port, UART_IIR);
+		serial_port_out(port, UART_IER, 0);
+
+		if (port->irqflags & IRQF_SHARED)
+			enable_irq(port->irq);
+		spin_unlock_irqrestore(&port->lock, flags);
+
+		/*
+		 * If the interrupt is not reasserted, or we otherwise
+		 * don't trust the iir, setup a timer to kick the UART
+		 * on a regular basis.
+		 */
+		if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||
+		    up->port.flags & UPF_BUG_THRE) {
+			up->bugs |= UART_BUG_THRE;
+		}
+	}
+
+	retval = up->ops->setup_irq(up);
+	if (retval)
+		goto out;
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (up->port.flags & UPF_FOURPORT) {
+		if (!up->port.irq)
+			up->port.mctrl |= TIOCM_OUT1;
+	} else
+		/*
+		 * Most PC uarts need OUT2 raised to enable interrupts.
+		 */
+		if (port->irq)
+			up->port.mctrl |= TIOCM_OUT2;
+
+	serial8250_set_mctrl(port, port->mctrl);
+
+	/* Serial over Lan (SoL) hack:
+	   Intel 8257x Gigabit ethernet chips have a
+	   16550 emulation, to be used for Serial Over Lan.
+	   Those chips take a longer time than a normal
+	   serial device to signalize that a transmission
+	   data was queued. Due to that, the above test generally
+	   fails. One solution would be to delay the reading of
+	   iir. However, this is not reliable, since the timeout
+	   is variable. So, let's just don't test if we receive
+	   TX irq. This way, we'll never enable UART_BUG_TXEN.
+	 */
+	if (up->port.flags & UPF_NO_TXEN_TEST)
+		goto dont_test_tx_en;
+
+	/*
+	 * Do a quick test to see if we receive an
+	 * interrupt when we enable the TX irq.
+	 */
+	serial_port_out(port, UART_IER, UART_IER_THRI);
+	lsr = serial_port_in(port, UART_LSR);
+	iir = serial_port_in(port, UART_IIR);
+	serial_port_out(port, UART_IER, 0);
+
+	if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
+		if (!(up->bugs & UART_BUG_TXEN)) {
+			up->bugs |= UART_BUG_TXEN;
+			pr_debug("ttyS%d - enabling bad tx status workarounds\n",
+				 serial_index(port));
+		}
+	} else {
+		up->bugs &= ~UART_BUG_TXEN;
+	}
+
+dont_test_tx_en:
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/*
+	 * Clear the interrupt registers again for luck, and clear the
+	 * saved flags to avoid getting false values from polling
+	 * routines or the previous session.
+	 */
+	serial_port_in(port, UART_LSR);
+	serial_port_in(port, UART_RX);
+	serial_port_in(port, UART_IIR);
+	serial_port_in(port, UART_MSR);
+	up->lsr_saved_flags = 0;
+	up->msr_saved_flags = 0;
+
+	/*
+	 * Request DMA channels for both RX and TX.
+	 */
+	if (up->dma) {
+		retval = serial8250_request_dma(up);
+		if (retval) {
+			pr_warn_ratelimited("ttyS%d - failed to request DMA\n",
+					    serial_index(port));
+			up->dma = NULL;
+		}
+	}
+
+	/*
+	 * Finally, enable interrupts.  Note: Modem status interrupts
+	 * are set via set_termios(), which will be occurring imminently
+	 * anyway, so we don't enable them here.
+	 */
+	up->ier = UART_IER_RLSI | UART_IER_RDI;
+	serial_port_out(port, UART_IER, up->ier);
+
+	if (port->flags & UPF_FOURPORT) {
+		unsigned int icp;
+		/*
+		 * Enable interrupts on the AST Fourport board
+		 */
+		icp = (port->iobase & 0xfe0) | 0x01f;
+		outb_p(0x80, icp);
+		inb_p(icp);
+	}
+	retval = 0;
+out:
+	serial8250_rpm_put(up);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(serial8250_do_startup);
+
+static int serial8250_startup(struct uart_port *port)
+{
+	if (port->startup)
+		return port->startup(port);
+	return serial8250_do_startup(port);
+}
+
+void serial8250_do_shutdown(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	serial8250_rpm_get(up);
+	/*
+	 * Disable interrupts from this port
+	 */
+	up->ier = 0;
+	serial_port_out(port, UART_IER, 0);
+
+	if (up->dma)
+		serial8250_release_dma(up);
+
+	spin_lock_irqsave(&port->lock, flags);
+	if (port->flags & UPF_FOURPORT) {
+		/* reset interrupts on the AST Fourport board */
+		inb((port->iobase & 0xfe0) | 0x1f);
+		port->mctrl |= TIOCM_OUT1;
+	} else
+		port->mctrl &= ~TIOCM_OUT2;
+
+	serial8250_set_mctrl(port, port->mctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	serial_port_out(port, UART_LCR,
+			serial_port_in(port, UART_LCR) & ~UART_LCR_SBC);
+	serial8250_clear_fifos(up);
+
+#ifdef CONFIG_SERIAL_8250_RSA
+	/*
+	 * Reset the RSA board back to 115kbps compat mode.
+	 */
+	disable_rsa(up);
+#endif
+
+	/*
+	 * Read data port to reset things, and then unlink from
+	 * the IRQ chain.
+	 */
+	serial_port_in(port, UART_RX);
+	serial8250_rpm_put(up);
+
+	up->ops->release_irq(up);
+}
+EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
+
+static void serial8250_shutdown(struct uart_port *port)
+{
+	if (port->shutdown)
+		port->shutdown(port);
+	else
+		serial8250_do_shutdown(port);
+}
+
+/*
+ * 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))
+		quot = 0x8001;
+	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;
+}
+
+static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
+					    tcflag_t c_cflag)
+{
+	unsigned char cval;
+
+	switch (c_cflag & CSIZE) {
+	case CS5:
+		cval = UART_LCR_WLEN5;
+		break;
+	case CS6:
+		cval = UART_LCR_WLEN6;
+		break;
+	case CS7:
+		cval = UART_LCR_WLEN7;
+		break;
+	default:
+	case CS8:
+		cval = UART_LCR_WLEN8;
+		break;
+	}
+
+	if (c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (c_cflag & PARENB) {
+		cval |= UART_LCR_PARITY;
+		if (up->bugs & UART_BUG_PARITY)
+			up->fifo_bug = true;
+	}
+	if (!(c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+#ifdef 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(up, baud, &frac);
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	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 ((baud < 2400 && !up->dma) || up->fifo_bug) {
+			up->fcr &= ~UART_FCR_TRIGGER_MASK;
+			up->fcr |= UART_FCR_TRIGGER_1;
+		}
+	}
+
+	/*
+	 * MCR-based auto flow control.  When AFE is enabled, RTS will be
+	 * deasserted when the receive FIFO contains more characters than
+	 * the trigger, or the MCR RTS bit is cleared.  In the case where
+	 * the remote UART is not using CTS auto flow control, we must
+	 * have sufficient FIFO entries for the latency of the remote
+	 * UART to respond.  IOW, at least 32 bytes of FIFO.
+	 */
+	if (up->capabilities & UART_CAP_AFE && port->fifosize >= 32) {
+		up->mcr &= ~UART_MCR_AFE;
+		if (termios->c_cflag & CRTSCTS)
+			up->mcr |= UART_MCR_AFE;
+	}
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characteres to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		port->ignore_status_mask |= UART_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 |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * CTS flow control flag and modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (!(up->bugs & UART_BUG_NOMSR) &&
+			UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+	if (up->capabilities & UART_CAP_UUE)
+		up->ier |= UART_IER_UUE;
+	if (up->capabilities & UART_CAP_RTOIE)
+		up->ier |= UART_IER_RTOIE;
+
+	serial_port_out(port, UART_IER, up->ier);
+
+	if (up->capabilities & UART_CAP_EFR) {
+		unsigned char efr = 0;
+		/*
+		 * TI16C752/Startech hardware flow control.  FIXME:
+		 * - TI16C752 requires control thresholds to be set.
+		 * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
+		 */
+		if (termios->c_cflag & CRTSCTS)
+			efr |= UART_EFR_CTS;
+
+		serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+		if (port->flags & UPF_EXAR_EFR)
+			serial_port_out(port, UART_XR_EFR, efr);
+		else
+			serial_port_out(port, UART_EFR, efr);
+	}
+
+	serial8250_set_divisor(port, baud, quot, frac);
+
+	/*
+	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
+	 * is written without DLAB set, this mode will be disabled.
+	 */
+	if (port->type == PORT_16750)
+		serial_port_out(port, UART_FCR, up->fcr);
+
+	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)
+			serial_port_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
+		serial_port_out(port, UART_FCR, up->fcr);	/* set fcr */
+	}
+	serial8250_set_mctrl(port, port->mctrl);
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+EXPORT_SYMBOL(serial8250_do_set_termios);
+
+static void
+serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
+		       struct ktermios *old)
+{
+	if (port->set_termios)
+		port->set_termios(port, termios, old);
+	else
+		serial8250_do_set_termios(port, termios, old);
+}
+
+static void
+serial8250_set_ldisc(struct uart_port *port, struct ktermios *termios)
+{
+	if (termios->c_line == N_PPS) {
+		port->flags |= UPF_HARDPPS_CD;
+		spin_lock_irq(&port->lock);
+		serial8250_enable_ms(port);
+		spin_unlock_irq(&port->lock);
+	} else {
+		port->flags &= ~UPF_HARDPPS_CD;
+		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
+			spin_lock_irq(&port->lock);
+			serial8250_disable_ms(port);
+			spin_unlock_irq(&port->lock);
+		}
+	}
+}
+
+
+void serial8250_do_pm(struct uart_port *port, unsigned int state,
+		      unsigned int oldstate)
+{
+	struct uart_8250_port *p = up_to_u8250p(port);
+
+	serial8250_set_sleep(p, state != 0);
+}
+EXPORT_SYMBOL(serial8250_do_pm);
+
+static void
+serial8250_pm(struct uart_port *port, unsigned int state,
+	      unsigned int oldstate)
+{
+	if (port->pm)
+		port->pm(port, state, oldstate);
+	else
+		serial8250_do_pm(port, state, oldstate);
+}
+
+static unsigned int serial8250_port_size(struct uart_8250_port *pt)
+{
+	if (pt->port.mapsize)
+		return pt->port.mapsize;
+	if (pt->port.iotype == UPIO_AU) {
+		if (pt->port.type == PORT_RT2880)
+			return 0x100;
+		return 0x1000;
+	}
+	if (is_omap1_8250(pt))
+		return 0x16 << pt->port.regshift;
+
+	return 8 << pt->port.regshift;
+}
+
+/*
+ * Resource handling.
+ */
+static int serial8250_request_std_resource(struct uart_8250_port *up)
+{
+	unsigned int size = serial8250_port_size(up);
+	struct uart_port *port = &up->port;
+	int ret = 0;
+
+	switch (port->iotype) {
+	case UPIO_AU:
+	case UPIO_TSI:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_MEM:
+		if (!port->mapbase)
+			break;
+
+		if (!request_mem_region(port->mapbase, size, "serial")) {
+			ret = -EBUSY;
+			break;
+		}
+
+		if (port->flags & UPF_IOREMAP) {
+			port->membase = ioremap_nocache(port->mapbase, size);
+			if (!port->membase) {
+				release_mem_region(port->mapbase, size);
+				ret = -ENOMEM;
+			}
+		}
+		break;
+
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		if (!request_region(port->iobase, size, "serial"))
+			ret = -EBUSY;
+		break;
+	}
+	return ret;
+}
+
+static void serial8250_release_std_resource(struct uart_8250_port *up)
+{
+	unsigned int size = serial8250_port_size(up);
+	struct uart_port *port = &up->port;
+
+	switch (port->iotype) {
+	case UPIO_AU:
+	case UPIO_TSI:
+	case UPIO_MEM32:
+	case UPIO_MEM32BE:
+	case UPIO_MEM:
+		if (!port->mapbase)
+			break;
+
+		if (port->flags & UPF_IOREMAP) {
+			iounmap(port->membase);
+			port->membase = NULL;
+		}
+
+		release_mem_region(port->mapbase, size);
+		break;
+
+	case UPIO_HUB6:
+	case UPIO_PORT:
+		release_region(port->iobase, size);
+		break;
+	}
+}
+
+static void serial8250_release_port(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	serial8250_release_std_resource(up);
+}
+
+static int serial8250_request_port(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	int ret;
+
+	if (port->type == PORT_8250_CIR)
+		return -ENODEV;
+
+	ret = serial8250_request_std_resource(up);
+
+	return ret;
+}
+
+static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
+{
+	const struct serial8250_config *conf_type = &uart_config[up->port.type];
+	unsigned char bytes;
+
+	bytes = conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(up->fcr)];
+
+	return bytes ? bytes : -EOPNOTSUPP;
+}
+
+static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes)
+{
+	const struct serial8250_config *conf_type = &uart_config[up->port.type];
+	int i;
+
+	if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)])
+		return -EOPNOTSUPP;
+
+	for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) {
+		if (bytes < conf_type->rxtrig_bytes[i])
+			/* Use the nearest lower value */
+			return (--i) << UART_FCR_R_TRIG_SHIFT;
+	}
+
+	return UART_FCR_R_TRIG_11;
+}
+
+static int do_get_rxtrig(struct tty_port *port)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport = state->uart_port;
+	struct uart_8250_port *up =
+		container_of(uport, struct uart_8250_port, port);
+
+	if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
+		return -EINVAL;
+
+	return fcr_get_rxtrig_bytes(up);
+}
+
+static int do_serial8250_get_rxtrig(struct tty_port *port)
+{
+	int rxtrig_bytes;
+
+	mutex_lock(&port->mutex);
+	rxtrig_bytes = do_get_rxtrig(port);
+	mutex_unlock(&port->mutex);
+
+	return rxtrig_bytes;
+}
+
+static ssize_t serial8250_get_attr_rx_trig_bytes(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	int rxtrig_bytes;
+
+	rxtrig_bytes = do_serial8250_get_rxtrig(port);
+	if (rxtrig_bytes < 0)
+		return rxtrig_bytes;
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", rxtrig_bytes);
+}
+
+static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
+{
+	struct uart_state *state = container_of(port, struct uart_state, port);
+	struct uart_port *uport = state->uart_port;
+	struct uart_8250_port *up =
+		container_of(uport, struct uart_8250_port, port);
+	int rxtrig;
+
+	if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 ||
+	    up->fifo_bug)
+		return -EINVAL;
+
+	rxtrig = bytes_to_fcr_rxtrig(up, bytes);
+	if (rxtrig < 0)
+		return rxtrig;
+
+	serial8250_clear_fifos(up);
+	up->fcr &= ~UART_FCR_TRIGGER_MASK;
+	up->fcr |= (unsigned char)rxtrig;
+	serial_out(up, UART_FCR, up->fcr);
+	return 0;
+}
+
+static int do_serial8250_set_rxtrig(struct tty_port *port, unsigned char bytes)
+{
+	int ret;
+
+	mutex_lock(&port->mutex);
+	ret = do_set_rxtrig(port, bytes);
+	mutex_unlock(&port->mutex);
+
+	return ret;
+}
+
+static ssize_t serial8250_set_attr_rx_trig_bytes(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct tty_port *port = dev_get_drvdata(dev);
+	unsigned char bytes;
+	int ret;
+
+	if (!count)
+		return -EINVAL;
+
+	ret = kstrtou8(buf, 10, &bytes);
+	if (ret < 0)
+		return ret;
+
+	ret = do_serial8250_set_rxtrig(port, bytes);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(rx_trig_bytes, S_IRUSR | S_IWUSR | S_IRGRP,
+		   serial8250_get_attr_rx_trig_bytes,
+		   serial8250_set_attr_rx_trig_bytes);
+
+static struct attribute *serial8250_dev_attrs[] = {
+	&dev_attr_rx_trig_bytes.attr,
+	NULL,
+	};
+
+static struct attribute_group serial8250_dev_attr_group = {
+	.attrs = serial8250_dev_attrs,
+	};
+
+static void register_dev_spec_attr_grp(struct uart_8250_port *up)
+{
+	const struct serial8250_config *conf_type = &uart_config[up->port.type];
+
+	if (conf_type->rxtrig_bytes[0])
+		up->port.attr_group = &serial8250_dev_attr_group;
+}
+
+static void serial8250_config_port(struct uart_port *port, int flags)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	int ret;
+
+	if (port->type == PORT_8250_CIR)
+		return;
+
+	/*
+	 * Find the region that we can probe for.  This in turn
+	 * tells us whether we can probe for the type of port.
+	 */
+	ret = serial8250_request_std_resource(up);
+	if (ret < 0)
+		return;
+
+	if (port->iotype != up->cur_iotype)
+		set_io_from_upio(port);
+
+	if (flags & UART_CONFIG_TYPE)
+		autoconfig(up);
+
+	/* if access method is AU, it is a 16550 with a quirk */
+	if (port->type == PORT_16550A && port->iotype == UPIO_AU)
+		up->bugs |= UART_BUG_NOMSR;
+
+	/* HW bugs may trigger IRQ while IIR == NO_INT */
+	if (port->type == PORT_TEGRA)
+		up->bugs |= UART_BUG_NOMSR;
+
+	if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
+		autoconfig_irq(up);
+
+	if (port->type == PORT_UNKNOWN)
+		serial8250_release_std_resource(up);
+
+	/* Fixme: probably not the best place for this */
+	if ((port->type == PORT_XR17V35X) ||
+	   (port->type == PORT_XR17D15X))
+		port->handle_irq = exar_handle_irq;
+
+	register_dev_spec_attr_grp(up);
+	up->fcr = uart_config[up->port.type].fcr;
+}
+
+static int
+serial8250_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (ser->irq >= nr_irqs || ser->irq < 0 ||
+	    ser->baud_base < 9600 || ser->type < PORT_UNKNOWN ||
+	    ser->type >= ARRAY_SIZE(uart_config) || ser->type == PORT_CIRRUS ||
+	    ser->type == PORT_STARTECH)
+		return -EINVAL;
+	return 0;
+}
+
+static const char *
+serial8250_type(struct uart_port *port)
+{
+	int type = port->type;
+
+	if (type >= ARRAY_SIZE(uart_config))
+		type = 0;
+	return uart_config[type].name;
+}
+
+static const struct uart_ops serial8250_pops = {
+	.tx_empty	= serial8250_tx_empty,
+	.set_mctrl	= serial8250_set_mctrl,
+	.get_mctrl	= serial8250_get_mctrl,
+	.stop_tx	= serial8250_stop_tx,
+	.start_tx	= serial8250_start_tx,
+	.throttle	= serial8250_throttle,
+	.unthrottle	= serial8250_unthrottle,
+	.stop_rx	= serial8250_stop_rx,
+	.enable_ms	= serial8250_enable_ms,
+	.break_ctl	= serial8250_break_ctl,
+	.startup	= serial8250_startup,
+	.shutdown	= serial8250_shutdown,
+	.set_termios	= serial8250_set_termios,
+	.set_ldisc	= serial8250_set_ldisc,
+	.pm		= serial8250_pm,
+	.type		= serial8250_type,
+	.release_port	= serial8250_release_port,
+	.request_port	= serial8250_request_port,
+	.config_port	= serial8250_config_port,
+	.verify_port	= serial8250_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = serial8250_get_poll_char,
+	.poll_put_char = serial8250_put_poll_char,
+#endif
+};
+
+void serial8250_init_port(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	spin_lock_init(&port->lock);
+	port->ops = &serial8250_pops;
+
+	up->cur_iotype = 0xFF;
+}
+EXPORT_SYMBOL_GPL(serial8250_init_port);
+
+void serial8250_set_defaults(struct uart_8250_port *up)
+{
+	struct uart_port *port = &up->port;
+
+	if (up->port.flags & UPF_FIXED_TYPE) {
+		unsigned int type = up->port.type;
+
+		if (!up->port.fifosize)
+			up->port.fifosize = uart_config[type].fifo_size;
+		if (!up->tx_loadsz)
+			up->tx_loadsz = uart_config[type].tx_loadsz;
+		if (!up->capabilities)
+			up->capabilities = uart_config[type].flags;
+	}
+
+	set_io_from_upio(port);
+
+	/* default dma handlers */
+	if (up->dma) {
+		if (!up->dma->tx_dma)
+			up->dma->tx_dma = serial8250_tx_dma;
+		if (!up->dma->rx_dma)
+			up->dma->rx_dma = serial8250_rx_dma;
+	}
+}
+EXPORT_SYMBOL_GPL(serial8250_set_defaults);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+
+static void serial8250_console_putchar(struct uart_port *port, int ch)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+
+	wait_for_xmitr(up, UART_LSR_THRE);
+	serial_port_out(port, UART_TX, ch);
+}
+
+/*
+ *	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.
+ */
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count)
+{
+	struct uart_port *port = &up->port;
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	touch_nmi_watchdog();
+
+	serial8250_rpm_get(up);
+
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock_irqsave(&port->lock, flags);
+	else
+		spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = serial_port_in(port, UART_IER);
+
+	if (up->capabilities & UART_CAP_UUE)
+		serial_port_out(port, UART_IER, UART_IER_UUE);
+	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);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(up, BOTH_EMPTY);
+	serial_port_out(port, UART_IER, ier);
+
+	/*
+	 *	The receive handling will happen properly because the
+	 *	receive ready bit will still be set; it is not cleared
+	 *	on read.  However, modem control will not, we must
+	 *	call it if we have saved something in the saved flags
+	 *	while processing with interrupts off.
+	 */
+	if (up->msr_saved_flags)
+		serial8250_modem_status(up);
+
+	if (locked)
+		spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+}
+
+static unsigned int probe_baud(struct uart_port *port)
+{
+	unsigned char lcr, dll, dlm;
+	unsigned int quot;
+
+	lcr = serial_port_in(port, UART_LCR);
+	serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);
+	dll = serial_port_in(port, UART_DLL);
+	dlm = serial_port_in(port, UART_DLM);
+	serial_port_out(port, UART_LCR, lcr);
+
+	quot = (dlm << 8) | dll;
+	return (port->uartclk / 16) / quot;
+}
+
+int serial8250_console_setup(struct uart_port *port, char *options, bool probe)
+{
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (!port->iobase && !port->membase)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else if (probe)
+		baud = probe_baud(port);
+
+	return uart_set_options(port, port->cons, baud, parity, bits, flow);
+}
+
+#endif /* CONFIG_SERIAL_8250_CONSOLE */

drivers/tty/serial/8250/Makefile

···
 # Makefile for the 8250 serial device drivers.
 #
 
-obj-$(CONFIG_SERIAL_8250)		+= 8250.o
+obj-$(CONFIG_SERIAL_8250)		+= 8250.o 8250_base.o
 8250-y					:= 8250_core.o
 8250-$(CONFIG_SERIAL_8250_PNP)		+= 8250_pnp.o
-8250-$(CONFIG_SERIAL_8250_DMA)		+= 8250_dma.o
+8250_base-y				:= 8250_port.o
+8250_base-$(CONFIG_SERIAL_8250_DMA)	+= 8250_dma.o
 obj-$(CONFIG_SERIAL_8250_GSC)		+= 8250_gsc.o
 obj-$(CONFIG_SERIAL_8250_PCI)		+= 8250_pci.o
 obj-$(CONFIG_SERIAL_8250_HP300)		+= 8250_hp300.o

include/linux/serial_8250.h

···
 unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr);
 void serial8250_tx_chars(struct uart_8250_port *up);
 unsigned int serial8250_modem_status(struct uart_8250_port *up);
+void serial8250_init_port(struct uart_8250_port *up);
+void serial8250_set_defaults(struct uart_8250_port *up);
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count);
+int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
 
 extern void serial8250_set_isa_configurator(void (*v)
 					(int port, struct uart_port *up,