serial: msm_serial_hs: Add MSM high speed UART driver

This driver supports UART-DM HW on MSM platforms. It uses the on
chip DMA to drive data transfers and has optional support for UART
power management independent of Linux suspend/resume and wakeup
from Rx.

The driver was originally developed by Google. It is functionally
equivalent to the version available at:
http://android.git.kernel.org/?p=kernel/experimental.git
the differences being:
1) Remove wakelocks and change unsupported DMA API.
2) Replace clock selection register codes by macros.
3) Fix checkpatch errors and add inline documentation.
4) Add runtime PM hooks for active power state transitions.
5) Handle error path and cleanup resources if required.

CC: Nick Pelly <[e-mail]>
Signed-off-by: Sankalp Bose <[e-mail]>
Signed-off-by: Mayank Rana <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/Kconfig

···
 	depends on SERIAL_MSM=y
 	select SERIAL_CORE_CONSOLE
 
+config SERIAL_MSM_HS
+	tristate "MSM UART High Speed: Serial Driver"
+	depends on ARCH_MSM
+	select SERIAL_CORE
+	help
+	  If you have a machine based on MSM family of SoCs, you
+	  can enable its onboard high speed serial port by enabling
+	  this option.
+
+	  Choose M here to compile it as a module. The module will be
+	  called msm_serial_hs.
+
 config SERIAL_VT8500
 	bool "VIA VT8500 on-chip serial port support"
 	depends on ARM && ARCH_VT8500

drivers/tty/serial/Makefile

···
 obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
 obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
 obj-$(CONFIG_SERIAL_MSM) += msm_serial.o
+obj-$(CONFIG_SERIAL_MSM_HS) += msm_serial_hs.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o

drivers/tty/serial/msm_serial_hs.c

···
+/*
+ * MSM 7k/8k High speed uart driver
+ *
+ * Copyright (c) 2007-2011, Code Aurora Forum. All rights reserved.
+ * Copyright (c) 2008 Google Inc.
+ * Modified: Nick Pelly <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * Has optional support for uart power management independent of linux
+ * suspend/resume:
+ *
+ * RX wakeup.
+ * UART wakeup can be triggered by RX activity (using a wakeup GPIO on the
+ * UART RX pin). This should only be used if there is not a wakeup
+ * GPIO on the UART CTS, and the first RX byte is known (for example, with the
+ * Bluetooth Texas Instruments HCILL protocol), since the first RX byte will
+ * always be lost. RTS will be asserted even while the UART is off in this mode
+ * of operation. See msm_serial_hs_platform_data.rx_wakeup_irq.
+ */
+
+#include <linux/module.h>
+
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+
+#include <linux/atomic.h>
+#include <asm/irq.h>
+#include <asm/system.h>
+
+#include <mach/hardware.h>
+#include <mach/dma.h>
+#include <linux/platform_data/msm_serial_hs.h>
+
+/* HSUART Registers */
+#define UARTDM_MR1_ADDR 0x0
+#define UARTDM_MR2_ADDR 0x4
+
+/* Data Mover result codes */
+#define RSLT_FIFO_CNTR_BMSK (0xE << 28)
+#define RSLT_VLD            BIT(1)
+
+/* write only register */
+#define UARTDM_CSR_ADDR 0x8
+#define UARTDM_CSR_115200 0xFF
+#define UARTDM_CSR_57600  0xEE
+#define UARTDM_CSR_38400  0xDD
+#define UARTDM_CSR_28800  0xCC
+#define UARTDM_CSR_19200  0xBB
+#define UARTDM_CSR_14400  0xAA
+#define UARTDM_CSR_9600   0x99
+#define UARTDM_CSR_7200   0x88
+#define UARTDM_CSR_4800   0x77
+#define UARTDM_CSR_3600   0x66
+#define UARTDM_CSR_2400   0x55
+#define UARTDM_CSR_1200   0x44
+#define UARTDM_CSR_600    0x33
+#define UARTDM_CSR_300    0x22
+#define UARTDM_CSR_150    0x11
+#define UARTDM_CSR_75     0x00
+
+/* write only register */
+#define UARTDM_TF_ADDR 0x70
+#define UARTDM_TF2_ADDR 0x74
+#define UARTDM_TF3_ADDR 0x78
+#define UARTDM_TF4_ADDR 0x7C
+
+/* write only register */
+#define UARTDM_CR_ADDR 0x10
+#define UARTDM_IMR_ADDR 0x14
+
+#define UARTDM_IPR_ADDR 0x18
+#define UARTDM_TFWR_ADDR 0x1c
+#define UARTDM_RFWR_ADDR 0x20
+#define UARTDM_HCR_ADDR 0x24
+#define UARTDM_DMRX_ADDR 0x34
+#define UARTDM_IRDA_ADDR 0x38
+#define UARTDM_DMEN_ADDR 0x3c
+
+/* UART_DM_NO_CHARS_FOR_TX */
+#define UARTDM_NCF_TX_ADDR 0x40
+
+#define UARTDM_BADR_ADDR 0x44
+
+#define UARTDM_SIM_CFG_ADDR 0x80
+/* Read Only register */
+#define UARTDM_SR_ADDR 0x8
+
+/* Read Only register */
+#define UARTDM_RF_ADDR  0x70
+#define UARTDM_RF2_ADDR 0x74
+#define UARTDM_RF3_ADDR 0x78
+#define UARTDM_RF4_ADDR 0x7C
+
+/* Read Only register */
+#define UARTDM_MISR_ADDR 0x10
+
+/* Read Only register */
+#define UARTDM_ISR_ADDR 0x14
+#define UARTDM_RX_TOTAL_SNAP_ADDR 0x38
+
+#define UARTDM_RXFS_ADDR 0x50
+
+/* Register field Mask Mapping */
+#define UARTDM_SR_PAR_FRAME_BMSK        BIT(5)
+#define UARTDM_SR_OVERRUN_BMSK          BIT(4)
+#define UARTDM_SR_TXEMT_BMSK            BIT(3)
+#define UARTDM_SR_TXRDY_BMSK            BIT(2)
+#define UARTDM_SR_RXRDY_BMSK            BIT(0)
+
+#define UARTDM_CR_TX_DISABLE_BMSK       BIT(3)
+#define UARTDM_CR_RX_DISABLE_BMSK       BIT(1)
+#define UARTDM_CR_TX_EN_BMSK            BIT(2)
+#define UARTDM_CR_RX_EN_BMSK            BIT(0)
+
+/* UARTDM_CR channel_comman bit value (register field is bits 8:4) */
+#define RESET_RX                0x10
+#define RESET_TX                0x20
+#define RESET_ERROR_STATUS      0x30
+#define RESET_BREAK_INT         0x40
+#define START_BREAK             0x50
+#define STOP_BREAK              0x60
+#define RESET_CTS               0x70
+#define RESET_STALE_INT         0x80
+#define RFR_LOW                 0xD0
+#define RFR_HIGH                0xE0
+#define CR_PROTECTION_EN        0x100
+#define STALE_EVENT_ENABLE      0x500
+#define STALE_EVENT_DISABLE     0x600
+#define FORCE_STALE_EVENT       0x400
+#define CLEAR_TX_READY          0x300
+#define RESET_TX_ERROR          0x800
+#define RESET_TX_DONE           0x810
+
+#define UARTDM_MR1_AUTO_RFR_LEVEL1_BMSK 0xffffff00
+#define UARTDM_MR1_AUTO_RFR_LEVEL0_BMSK 0x3f
+#define UARTDM_MR1_CTS_CTL_BMSK 0x40
+#define UARTDM_MR1_RX_RDY_CTL_BMSK 0x80
+
+#define UARTDM_MR2_ERROR_MODE_BMSK 0x40
+#define UARTDM_MR2_BITS_PER_CHAR_BMSK 0x30
+
+/* bits per character configuration */
+#define FIVE_BPC  (0 << 4)
+#define SIX_BPC   (1 << 4)
+#define SEVEN_BPC (2 << 4)
+#define EIGHT_BPC (3 << 4)
+
+#define UARTDM_MR2_STOP_BIT_LEN_BMSK 0xc
+#define STOP_BIT_ONE (1 << 2)
+#define STOP_BIT_TWO (3 << 2)
+
+#define UARTDM_MR2_PARITY_MODE_BMSK 0x3
+
+/* Parity configuration */
+#define NO_PARITY 0x0
+#define EVEN_PARITY 0x1
+#define ODD_PARITY 0x2
+#define SPACE_PARITY 0x3
+
+#define UARTDM_IPR_STALE_TIMEOUT_MSB_BMSK 0xffffff80
+#define UARTDM_IPR_STALE_LSB_BMSK 0x1f
+
+/* These can be used for both ISR and IMR register */
+#define UARTDM_ISR_TX_READY_BMSK        BIT(7)
+#define UARTDM_ISR_CURRENT_CTS_BMSK     BIT(6)
+#define UARTDM_ISR_DELTA_CTS_BMSK       BIT(5)
+#define UARTDM_ISR_RXLEV_BMSK           BIT(4)
+#define UARTDM_ISR_RXSTALE_BMSK         BIT(3)
+#define UARTDM_ISR_RXBREAK_BMSK         BIT(2)
+#define UARTDM_ISR_RXHUNT_BMSK          BIT(1)
+#define UARTDM_ISR_TXLEV_BMSK           BIT(0)
+
+/* Field definitions for UART_DM_DMEN*/
+#define UARTDM_TX_DM_EN_BMSK 0x1
+#define UARTDM_RX_DM_EN_BMSK 0x2
+
+#define UART_FIFOSIZE 64
+#define UARTCLK 7372800
+
+/* Rx DMA request states */
+enum flush_reason {
+	FLUSH_NONE,
+	FLUSH_DATA_READY,
+	FLUSH_DATA_INVALID,  /* values after this indicate invalid data */
+	FLUSH_IGNORE = FLUSH_DATA_INVALID,
+	FLUSH_STOP,
+	FLUSH_SHUTDOWN,
+};
+
+/* UART clock states */
+enum msm_hs_clk_states_e {
+	MSM_HS_CLK_PORT_OFF,     /* port not in use */
+	MSM_HS_CLK_OFF,          /* clock disabled */
+	MSM_HS_CLK_REQUEST_OFF,  /* disable after TX and RX flushed */
+	MSM_HS_CLK_ON,           /* clock enabled */
+};
+
+/* Track the forced RXSTALE flush during clock off sequence.
+ * These states are only valid during MSM_HS_CLK_REQUEST_OFF */
+enum msm_hs_clk_req_off_state_e {
+	CLK_REQ_OFF_START,
+	CLK_REQ_OFF_RXSTALE_ISSUED,
+	CLK_REQ_OFF_FLUSH_ISSUED,
+	CLK_REQ_OFF_RXSTALE_FLUSHED,
+};
+
+/**
+ * struct msm_hs_tx
+ * @tx_ready_int_en: ok to dma more tx?
+ * @dma_in_flight: tx dma in progress
+ * @xfer: top level DMA command pointer structure
+ * @command_ptr: third level command struct pointer
+ * @command_ptr_ptr: second level command list struct pointer
+ * @mapped_cmd_ptr: DMA view of third level command struct
+ * @mapped_cmd_ptr_ptr: DMA view of second level command list struct
+ * @tx_count: number of bytes to transfer in DMA transfer
+ * @dma_base: DMA view of UART xmit buffer
+ *
+ * This structure describes a single Tx DMA transaction. MSM DMA
+ * commands have two levels of indirection. The top level command
+ * ptr points to a list of command ptr which in turn points to a
+ * single DMA 'command'. In our case each Tx transaction consists
+ * of a single second level pointer pointing to a 'box type' command.
+ */
+struct msm_hs_tx {
+	unsigned int tx_ready_int_en;
+	unsigned int dma_in_flight;
+	struct msm_dmov_cmd xfer;
+	dmov_box *command_ptr;
+	u32 *command_ptr_ptr;
+	dma_addr_t mapped_cmd_ptr;
+	dma_addr_t mapped_cmd_ptr_ptr;
+	int tx_count;
+	dma_addr_t dma_base;
+};
+
+/**
+ * struct msm_hs_rx
+ * @flush: Rx DMA request state
+ * @xfer: top level DMA command pointer structure
+ * @cmdptr_dmaaddr: DMA view of second level command structure
+ * @command_ptr: third level DMA command pointer structure
+ * @command_ptr_ptr: second level DMA command list pointer
+ * @mapped_cmd_ptr: DMA view of the third level command structure
+ * @wait: wait for DMA completion before shutdown
+ * @buffer: destination buffer for RX DMA
+ * @rbuffer: DMA view of buffer
+ * @pool: dma pool out of which coherent rx buffer is allocated
+ * @tty_work: private work-queue for tty flip buffer push task
+ *
+ * This structure describes a single Rx DMA transaction. Rx DMA
+ * transactions use box mode DMA commands.
+ */
+struct msm_hs_rx {
+	enum flush_reason flush;
+	struct msm_dmov_cmd xfer;
+	dma_addr_t cmdptr_dmaaddr;
+	dmov_box *command_ptr;
+	u32 *command_ptr_ptr;
+	dma_addr_t mapped_cmd_ptr;
+	wait_queue_head_t wait;
+	dma_addr_t rbuffer;
+	unsigned char *buffer;
+	struct dma_pool *pool;
+	struct work_struct tty_work;
+};
+
+/**
+ * struct msm_hs_rx_wakeup
+ * @irq: IRQ line to be configured as interrupt source on Rx activity
+ * @ignore: boolean value. 1 = ignore the wakeup interrupt
+ * @rx_to_inject: extra character to be inserted to Rx tty on wakeup
+ * @inject_rx: 1 = insert rx_to_inject. 0 = do not insert extra character
+ *
+ * This is an optional structure required for UART Rx GPIO IRQ based
+ * wakeup from low power state. UART wakeup can be triggered by RX activity
+ * (using a wakeup GPIO on the UART RX pin). This should only be used if
+ * there is not a wakeup GPIO on the UART CTS, and the first RX byte is
+ * known (eg., with the Bluetooth Texas Instruments HCILL protocol),
+ * since the first RX byte will always be lost. RTS will be asserted even
+ * while the UART is clocked off in this mode of operation.
+ */
+struct msm_hs_rx_wakeup {
+	int irq;  /* < 0 indicates low power wakeup disabled */
+	unsigned char ignore;
+	unsigned char inject_rx;
+	char rx_to_inject;
+};
+
+/**
+ * struct msm_hs_port
+ * @uport: embedded uart port structure
+ * @imr_reg: shadow value of UARTDM_IMR
+ * @clk: uart input clock handle
+ * @tx: Tx transaction related data structure
+ * @rx: Rx transaction related data structure
+ * @dma_tx_channel: Tx DMA command channel
+ * @dma_rx_channel Rx DMA command channel
+ * @dma_tx_crci: Tx channel rate control interface number
+ * @dma_rx_crci: Rx channel rate control interface number
+ * @clk_off_timer: Timer to poll DMA event completion before clock off
+ * @clk_off_delay: clk_off_timer poll interval
+ * @clk_state: overall clock state
+ * @clk_req_off_state: post flush clock states
+ * @rx_wakeup: optional rx_wakeup feature related data
+ * @exit_lpm_cb: optional callback to exit low power mode
+ *
+ * Low level serial port structure.
+ */
+struct msm_hs_port {
+	struct uart_port uport;
+	unsigned long imr_reg;
+	struct clk *clk;
+	struct msm_hs_tx tx;
+	struct msm_hs_rx rx;
+
+	int dma_tx_channel;
+	int dma_rx_channel;
+	int dma_tx_crci;
+	int dma_rx_crci;
+
+	struct hrtimer clk_off_timer;
+	ktime_t clk_off_delay;
+	enum msm_hs_clk_states_e clk_state;
+	enum msm_hs_clk_req_off_state_e clk_req_off_state;
+
+	struct msm_hs_rx_wakeup rx_wakeup;
+	void (*exit_lpm_cb)(struct uart_port *);
+};
+
+#define MSM_UARTDM_BURST_SIZE 16   /* DM burst size (in bytes) */
+#define UARTDM_TX_BUF_SIZE UART_XMIT_SIZE
+#define UARTDM_RX_BUF_SIZE 512
+
+#define UARTDM_NR 2
+
+static struct msm_hs_port q_uart_port[UARTDM_NR];
+static struct platform_driver msm_serial_hs_platform_driver;
+static struct uart_driver msm_hs_driver;
+static struct uart_ops msm_hs_ops;
+static struct workqueue_struct *msm_hs_workqueue;
+
+#define UARTDM_TO_MSM(uart_port) \
+	container_of((uart_port), struct msm_hs_port, uport)
+
+static unsigned int use_low_power_rx_wakeup(struct msm_hs_port
+						   *msm_uport)
+{
+	return (msm_uport->rx_wakeup.irq >= 0);
+}
+
+static unsigned int msm_hs_read(struct uart_port *uport,
+				       unsigned int offset)
+{
+	return ioread32(uport->membase + offset);
+}
+
+static void msm_hs_write(struct uart_port *uport, unsigned int offset,
+				 unsigned int value)
+{
+	iowrite32(value, uport->membase + offset);
+}
+
+static void msm_hs_release_port(struct uart_port *port)
+{
+	iounmap(port->membase);
+}
+
+static int msm_hs_request_port(struct uart_port *port)
+{
+	port->membase = ioremap(port->mapbase, PAGE_SIZE);
+	if (unlikely(!port->membase))
+		return -ENOMEM;
+
+	/* configure the CR Protection to Enable */
+	msm_hs_write(port, UARTDM_CR_ADDR, CR_PROTECTION_EN);
+	return 0;
+}
+
+static int __devexit msm_hs_remove(struct platform_device *pdev)
+{
+
+	struct msm_hs_port *msm_uport;
+	struct device *dev;
+
+	if (pdev->id < 0 || pdev->id >= UARTDM_NR) {
+		printk(KERN_ERR "Invalid plaform device ID = %d\n", pdev->id);
+		return -EINVAL;
+	}
+
+	msm_uport = &q_uart_port[pdev->id];
+	dev = msm_uport->uport.dev;
+
+	dma_unmap_single(dev, msm_uport->rx.mapped_cmd_ptr, sizeof(dmov_box),
+			 DMA_TO_DEVICE);
+	dma_pool_free(msm_uport->rx.pool, msm_uport->rx.buffer,
+		      msm_uport->rx.rbuffer);
+	dma_pool_destroy(msm_uport->rx.pool);
+
+	dma_unmap_single(dev, msm_uport->rx.cmdptr_dmaaddr, sizeof(u32 *),
+			 DMA_TO_DEVICE);
+	dma_unmap_single(dev, msm_uport->tx.mapped_cmd_ptr_ptr, sizeof(u32 *),
+			 DMA_TO_DEVICE);
+	dma_unmap_single(dev, msm_uport->tx.mapped_cmd_ptr, sizeof(dmov_box),
+			 DMA_TO_DEVICE);
+
+	uart_remove_one_port(&msm_hs_driver, &msm_uport->uport);
+	clk_put(msm_uport->clk);
+
+	/* Free the tx resources */
+	kfree(msm_uport->tx.command_ptr);
+	kfree(msm_uport->tx.command_ptr_ptr);
+
+	/* Free the rx resources */
+	kfree(msm_uport->rx.command_ptr);
+	kfree(msm_uport->rx.command_ptr_ptr);
+
+	iounmap(msm_uport->uport.membase);
+
+	return 0;
+}
+
+static int msm_hs_init_clk_locked(struct uart_port *uport)
+{
+	int ret;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	ret = clk_enable(msm_uport->clk);
+	if (ret) {
+		printk(KERN_ERR "Error could not turn on UART clk\n");
+		return ret;
+	}
+
+	/* Set up the MREG/NREG/DREG/MNDREG */
+	ret = clk_set_rate(msm_uport->clk, uport->uartclk);
+	if (ret) {
+		printk(KERN_WARNING "Error setting clock rate on UART\n");
+		clk_disable(msm_uport->clk);
+		return ret;
+	}
+
+	msm_uport->clk_state = MSM_HS_CLK_ON;
+	return 0;
+}
+
+/* Enable and Disable clocks  (Used for power management) */
+static void msm_hs_pm(struct uart_port *uport, unsigned int state,
+		      unsigned int oldstate)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	if (use_low_power_rx_wakeup(msm_uport) ||
+	    msm_uport->exit_lpm_cb)
+		return;  /* ignore linux PM states,
+			    use msm_hs_request_clock API */
+
+	switch (state) {
+	case 0:
+		clk_enable(msm_uport->clk);
+		break;
+	case 3:
+		clk_disable(msm_uport->clk);
+		break;
+	default:
+		dev_err(uport->dev, "msm_serial: Unknown PM state %d\n",
+			state);
+	}
+}
+
+/*
+ * programs the UARTDM_CSR register with correct bit rates
+ *
+ * Interrupts should be disabled before we are called, as
+ * we modify Set Baud rate
+ * Set receive stale interrupt level, dependant on Bit Rate
+ * Goal is to have around 8 ms before indicate stale.
+ * roundup (((Bit Rate * .008) / 10) + 1
+ */
+static void msm_hs_set_bps_locked(struct uart_port *uport,
+				  unsigned int bps)
+{
+	unsigned long rxstale;
+	unsigned long data;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	switch (bps) {
+	case 300:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_75);
+		rxstale = 1;
+		break;
+	case 600:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_150);
+		rxstale = 1;
+		break;
+	case 1200:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_300);
+		rxstale = 1;
+		break;
+	case 2400:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_600);
+		rxstale = 1;
+		break;
+	case 4800:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_1200);
+		rxstale = 1;
+		break;
+	case 9600:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_2400);
+		rxstale = 2;
+		break;
+	case 14400:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_3600);
+		rxstale = 3;
+		break;
+	case 19200:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_4800);
+		rxstale = 4;
+		break;
+	case 28800:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_7200);
+		rxstale = 6;
+		break;
+	case 38400:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_9600);
+		rxstale = 8;
+		break;
+	case 57600:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_14400);
+		rxstale = 16;
+		break;
+	case 76800:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_19200);
+		rxstale = 16;
+		break;
+	case 115200:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_28800);
+		rxstale = 31;
+		break;
+	case 230400:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_57600);
+		rxstale = 31;
+		break;
+	case 460800:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_115200);
+		rxstale = 31;
+		break;
+	case 4000000:
+	case 3686400:
+	case 3200000:
+	case 3500000:
+	case 3000000:
+	case 2500000:
+	case 1500000:
+	case 1152000:
+	case 1000000:
+	case 921600:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_115200);
+		rxstale = 31;
+		break;
+	default:
+		msm_hs_write(uport, UARTDM_CSR_ADDR, UARTDM_CSR_2400);
+		/* default to 9600 */
+		bps = 9600;
+		rxstale = 2;
+		break;
+	}
+	if (bps > 460800)
+		uport->uartclk = bps * 16;
+	else
+		uport->uartclk = UARTCLK;
+
+	if (clk_set_rate(msm_uport->clk, uport->uartclk)) {
+		printk(KERN_WARNING "Error setting clock rate on UART\n");
+		return;
+	}
+
+	data = rxstale & UARTDM_IPR_STALE_LSB_BMSK;
+	data |= UARTDM_IPR_STALE_TIMEOUT_MSB_BMSK & (rxstale << 2);
+
+	msm_hs_write(uport, UARTDM_IPR_ADDR, data);
+}
+
+/*
+ * termios :  new ktermios
+ * oldtermios:  old ktermios previous setting
+ *
+ * Configure the serial port
+ */
+static void msm_hs_set_termios(struct uart_port *uport,
+			       struct ktermios *termios,
+			       struct ktermios *oldtermios)
+{
+	unsigned int bps;
+	unsigned long data;
+	unsigned long flags;
+	unsigned int c_cflag = termios->c_cflag;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	spin_lock_irqsave(&uport->lock, flags);
+	clk_enable(msm_uport->clk);
+
+	/* 300 is the minimum baud support by the driver  */
+	bps = uart_get_baud_rate(uport, termios, oldtermios, 200, 4000000);
+
+	/* Temporary remapping  200 BAUD to 3.2 mbps */
+	if (bps == 200)
+		bps = 3200000;
+
+	msm_hs_set_bps_locked(uport, bps);
+
+	data = msm_hs_read(uport, UARTDM_MR2_ADDR);
+	data &= ~UARTDM_MR2_PARITY_MODE_BMSK;
+	/* set parity */
+	if (PARENB == (c_cflag & PARENB)) {
+		if (PARODD == (c_cflag & PARODD))
+			data |= ODD_PARITY;
+		else if (CMSPAR == (c_cflag & CMSPAR))
+			data |= SPACE_PARITY;
+		else
+			data |= EVEN_PARITY;
+	}
+
+	/* Set bits per char */
+	data &= ~UARTDM_MR2_BITS_PER_CHAR_BMSK;
+
+	switch (c_cflag & CSIZE) {
+	case CS5:
+		data |= FIVE_BPC;
+		break;
+	case CS6:
+		data |= SIX_BPC;
+		break;
+	case CS7:
+		data |= SEVEN_BPC;
+		break;
+	default:
+		data |= EIGHT_BPC;
+		break;
+	}
+	/* stop bits */
+	if (c_cflag & CSTOPB) {
+		data |= STOP_BIT_TWO;
+	} else {
+		/* otherwise 1 stop bit */
+		data |= STOP_BIT_ONE;
+	}
+	data |= UARTDM_MR2_ERROR_MODE_BMSK;
+	/* write parity/bits per char/stop bit configuration */
+	msm_hs_write(uport, UARTDM_MR2_ADDR, data);
+
+	/* Configure HW flow control */
+	data = msm_hs_read(uport, UARTDM_MR1_ADDR);
+
+	data &= ~(UARTDM_MR1_CTS_CTL_BMSK | UARTDM_MR1_RX_RDY_CTL_BMSK);
+
+	if (c_cflag & CRTSCTS) {
+		data |= UARTDM_MR1_CTS_CTL_BMSK;
+		data |= UARTDM_MR1_RX_RDY_CTL_BMSK;
+	}
+
+	msm_hs_write(uport, UARTDM_MR1_ADDR, data);
+
+	uport->ignore_status_mask = termios->c_iflag & INPCK;
+	uport->ignore_status_mask |= termios->c_iflag & IGNPAR;
+	uport->read_status_mask = (termios->c_cflag & CREAD);
+
+	msm_hs_write(uport, UARTDM_IMR_ADDR, 0);
+
+	/* Set Transmit software time out */
+	uart_update_timeout(uport, c_cflag, bps);
+
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_RX);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_TX);
+
+	if (msm_uport->rx.flush == FLUSH_NONE) {
+		msm_uport->rx.flush = FLUSH_IGNORE;
+		msm_dmov_stop_cmd(msm_uport->dma_rx_channel, NULL, 1);
+	}
+
+	msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+
+	clk_disable(msm_uport->clk);
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+/*
+ *  Standard API, Transmitter
+ *  Any character in the transmit shift register is sent
+ */
+static unsigned int msm_hs_tx_empty(struct uart_port *uport)
+{
+	unsigned int data;
+	unsigned int ret = 0;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	clk_enable(msm_uport->clk);
+
+	data = msm_hs_read(uport, UARTDM_SR_ADDR);
+	if (data & UARTDM_SR_TXEMT_BMSK)
+		ret = TIOCSER_TEMT;
+
+	clk_disable(msm_uport->clk);
+
+	return ret;
+}
+
+/*
+ *  Standard API, Stop transmitter.
+ *  Any character in the transmit shift register is sent as
+ *  well as the current data mover transfer .
+ */
+static void msm_hs_stop_tx_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	msm_uport->tx.tx_ready_int_en = 0;
+}
+
+/*
+ *  Standard API, Stop receiver as soon as possible.
+ *
+ *  Function immediately terminates the operation of the
+ *  channel receiver and any incoming characters are lost. None
+ *  of the receiver status bits are affected by this command and
+ *  characters that are already in the receive FIFO there.
+ */
+static void msm_hs_stop_rx_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+	unsigned int data;
+
+	clk_enable(msm_uport->clk);
+
+	/* disable dlink */
+	data = msm_hs_read(uport, UARTDM_DMEN_ADDR);
+	data &= ~UARTDM_RX_DM_EN_BMSK;
+	msm_hs_write(uport, UARTDM_DMEN_ADDR, data);
+
+	/* Disable the receiver */
+	if (msm_uport->rx.flush == FLUSH_NONE)
+		msm_dmov_stop_cmd(msm_uport->dma_rx_channel, NULL, 1);
+
+	if (msm_uport->rx.flush != FLUSH_SHUTDOWN)
+		msm_uport->rx.flush = FLUSH_STOP;
+
+	clk_disable(msm_uport->clk);
+}
+
+/*  Transmit the next chunk of data */
+static void msm_hs_submit_tx_locked(struct uart_port *uport)
+{
+	int left;
+	int tx_count;
+	dma_addr_t src_addr;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+	struct msm_hs_tx *tx = &msm_uport->tx;
+	struct circ_buf *tx_buf = &msm_uport->uport.state->xmit;
+
+	if (uart_circ_empty(tx_buf) || uport->state->port.tty->stopped) {
+		msm_hs_stop_tx_locked(uport);
+		return;
+	}
+
+	tx->dma_in_flight = 1;
+
+	tx_count = uart_circ_chars_pending(tx_buf);
+
+	if (UARTDM_TX_BUF_SIZE < tx_count)
+		tx_count = UARTDM_TX_BUF_SIZE;
+
+	left = UART_XMIT_SIZE - tx_buf->tail;
+
+	if (tx_count > left)
+		tx_count = left;
+
+	src_addr = tx->dma_base + tx_buf->tail;
+	dma_sync_single_for_device(uport->dev, src_addr, tx_count,
+				   DMA_TO_DEVICE);
+
+	tx->command_ptr->num_rows = (((tx_count + 15) >> 4) << 16) |
+				     ((tx_count + 15) >> 4);
+	tx->command_ptr->src_row_addr = src_addr;
+
+	dma_sync_single_for_device(uport->dev, tx->mapped_cmd_ptr,
+				   sizeof(dmov_box), DMA_TO_DEVICE);
+
+	*tx->command_ptr_ptr = CMD_PTR_LP | DMOV_CMD_ADDR(tx->mapped_cmd_ptr);
+
+	dma_sync_single_for_device(uport->dev, tx->mapped_cmd_ptr_ptr,
+				   sizeof(u32 *), DMA_TO_DEVICE);
+
+	/* Save tx_count to use in Callback */
+	tx->tx_count = tx_count;
+	msm_hs_write(uport, UARTDM_NCF_TX_ADDR, tx_count);
+
+	/* Disable the tx_ready interrupt */
+	msm_uport->imr_reg &= ~UARTDM_ISR_TX_READY_BMSK;
+	msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+	msm_dmov_enqueue_cmd(msm_uport->dma_tx_channel, &tx->xfer);
+}
+
+/* Start to receive the next chunk of data */
+static void msm_hs_start_rx_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_STALE_INT);
+	msm_hs_write(uport, UARTDM_DMRX_ADDR, UARTDM_RX_BUF_SIZE);
+	msm_hs_write(uport, UARTDM_CR_ADDR, STALE_EVENT_ENABLE);
+	msm_uport->imr_reg |= UARTDM_ISR_RXLEV_BMSK;
+	msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+
+	msm_uport->rx.flush = FLUSH_NONE;
+	msm_dmov_enqueue_cmd(msm_uport->dma_rx_channel, &msm_uport->rx.xfer);
+
+	/* might have finished RX and be ready to clock off */
+	hrtimer_start(&msm_uport->clk_off_timer, msm_uport->clk_off_delay,
+			HRTIMER_MODE_REL);
+}
+
+/* Enable the transmitter Interrupt */
+static void msm_hs_start_tx_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	clk_enable(msm_uport->clk);
+
+	if (msm_uport->exit_lpm_cb)
+		msm_uport->exit_lpm_cb(uport);
+
+	if (msm_uport->tx.tx_ready_int_en == 0) {
+		msm_uport->tx.tx_ready_int_en = 1;
+		msm_hs_submit_tx_locked(uport);
+	}
+
+	clk_disable(msm_uport->clk);
+}
+
+/*
+ *  This routine is called when we are done with a DMA transfer
+ *
+ *  This routine is registered with Data mover when we set
+ *  up a Data Mover transfer. It is called from Data mover ISR
+ *  when the DMA transfer is done.
+ */
+static void msm_hs_dmov_tx_callback(struct msm_dmov_cmd *cmd_ptr,
+					unsigned int result,
+					struct msm_dmov_errdata *err)
+{
+	unsigned long flags;
+	struct msm_hs_port *msm_uport;
+
+	/* DMA did not finish properly */
+	WARN_ON((((result & RSLT_FIFO_CNTR_BMSK) >> 28) == 1) &&
+		!(result & RSLT_VLD));
+
+	msm_uport = container_of(cmd_ptr, struct msm_hs_port, tx.xfer);
+
+	spin_lock_irqsave(&msm_uport->uport.lock, flags);
+	clk_enable(msm_uport->clk);
+
+	msm_uport->imr_reg |= UARTDM_ISR_TX_READY_BMSK;
+	msm_hs_write(&msm_uport->uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+
+	clk_disable(msm_uport->clk);
+	spin_unlock_irqrestore(&msm_uport->uport.lock, flags);
+}
+
+/*
+ * This routine is called when we are done with a DMA transfer or the
+ * a flush has been sent to the data mover driver.
+ *
+ * This routine is registered with Data mover when we set up a Data Mover
+ *  transfer. It is called from Data mover ISR when the DMA transfer is done.
+ */
+static void msm_hs_dmov_rx_callback(struct msm_dmov_cmd *cmd_ptr,
+					unsigned int result,
+					struct msm_dmov_errdata *err)
+{
+	int retval;
+	int rx_count;
+	unsigned long status;
+	unsigned int error_f = 0;
+	unsigned long flags;
+	unsigned int flush;
+	struct tty_struct *tty;
+	struct uart_port *uport;
+	struct msm_hs_port *msm_uport;
+
+	msm_uport = container_of(cmd_ptr, struct msm_hs_port, rx.xfer);
+	uport = &msm_uport->uport;
+
+	spin_lock_irqsave(&uport->lock, flags);
+	clk_enable(msm_uport->clk);
+
+	tty = uport->state->port.tty;
+
+	msm_hs_write(uport, UARTDM_CR_ADDR, STALE_EVENT_DISABLE);
+
+	status = msm_hs_read(uport, UARTDM_SR_ADDR);
+
+	/* overflow is not connect to data in a FIFO */
+	if (unlikely((status & UARTDM_SR_OVERRUN_BMSK) &&
+		     (uport->read_status_mask & CREAD))) {
+		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		uport->icount.buf_overrun++;
+		error_f = 1;
+	}
+
+	if (!(uport->ignore_status_mask & INPCK))
+		status = status & ~(UARTDM_SR_PAR_FRAME_BMSK);
+
+	if (unlikely(status & UARTDM_SR_PAR_FRAME_BMSK)) {
+		/* Can not tell difference between parity & frame error */
+		uport->icount.parity++;
+		error_f = 1;
+		if (uport->ignore_status_mask & IGNPAR)
+			tty_insert_flip_char(tty, 0, TTY_PARITY);
+	}
+
+	if (error_f)
+		msm_hs_write(uport, UARTDM_CR_ADDR, RESET_ERROR_STATUS);
+
+	if (msm_uport->clk_req_off_state == CLK_REQ_OFF_FLUSH_ISSUED)
+		msm_uport->clk_req_off_state = CLK_REQ_OFF_RXSTALE_FLUSHED;
+
+	flush = msm_uport->rx.flush;
+	if (flush == FLUSH_IGNORE)
+		msm_hs_start_rx_locked(uport);
+	if (flush == FLUSH_STOP)
+		msm_uport->rx.flush = FLUSH_SHUTDOWN;
+	if (flush >= FLUSH_DATA_INVALID)
+		goto out;
+
+	rx_count = msm_hs_read(uport, UARTDM_RX_TOTAL_SNAP_ADDR);
+
+	if (0 != (uport->read_status_mask & CREAD)) {
+		retval = tty_insert_flip_string(tty, msm_uport->rx.buffer,
+						rx_count);
+		BUG_ON(retval != rx_count);
+	}
+
+	msm_hs_start_rx_locked(uport);
+
+out:
+	clk_disable(msm_uport->clk);
+
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	if (flush < FLUSH_DATA_INVALID)
+		queue_work(msm_hs_workqueue, &msm_uport->rx.tty_work);
+}
+
+static void msm_hs_tty_flip_buffer_work(struct work_struct *work)
+{
+	struct msm_hs_port *msm_uport =
+			container_of(work, struct msm_hs_port, rx.tty_work);
+	struct tty_struct *tty = msm_uport->uport.state->port.tty;
+
+	tty_flip_buffer_push(tty);
+}
+
+/*
+ *  Standard API, Current states of modem control inputs
+ *
+ * Since CTS can be handled entirely by HARDWARE we always
+ * indicate clear to send and count on the TX FIFO to block when
+ * it fills up.
+ *
+ * - TIOCM_DCD
+ * - TIOCM_CTS
+ * - TIOCM_DSR
+ * - TIOCM_RI
+ *  (Unsupported) DCD and DSR will return them high. RI will return low.
+ */
+static unsigned int msm_hs_get_mctrl_locked(struct uart_port *uport)
+{
+	return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;
+}
+
+/*
+ * True enables UART auto RFR, which indicates we are ready for data if the RX
+ * buffer is not full. False disables auto RFR, and deasserts RFR to indicate
+ * we are not ready for data. Must be called with UART clock on.
+ */
+static void set_rfr_locked(struct uart_port *uport, int auto_rfr)
+{
+	unsigned int data;
+
+	data = msm_hs_read(uport, UARTDM_MR1_ADDR);
+
+	if (auto_rfr) {
+		/* enable auto ready-for-receiving */
+		data |= UARTDM_MR1_RX_RDY_CTL_BMSK;
+		msm_hs_write(uport, UARTDM_MR1_ADDR, data);
+	} else {
+		/* disable auto ready-for-receiving */
+		data &= ~UARTDM_MR1_RX_RDY_CTL_BMSK;
+		msm_hs_write(uport, UARTDM_MR1_ADDR, data);
+		/* RFR is active low, set high */
+		msm_hs_write(uport, UARTDM_CR_ADDR, RFR_HIGH);
+	}
+}
+
+/*
+ *  Standard API, used to set or clear RFR
+ */
+static void msm_hs_set_mctrl_locked(struct uart_port *uport,
+				    unsigned int mctrl)
+{
+	unsigned int auto_rfr;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	clk_enable(msm_uport->clk);
+
+	auto_rfr = TIOCM_RTS & mctrl ? 1 : 0;
+	set_rfr_locked(uport, auto_rfr);
+
+	clk_disable(msm_uport->clk);
+}
+
+/* Standard API, Enable modem status (CTS) interrupt  */
+static void msm_hs_enable_ms_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	clk_enable(msm_uport->clk);
+
+	/* Enable DELTA_CTS Interrupt */
+	msm_uport->imr_reg |= UARTDM_ISR_DELTA_CTS_BMSK;
+	msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+
+	clk_disable(msm_uport->clk);
+
+}
+
+/*
+ *  Standard API, Break Signal
+ *
+ * Control the transmission of a break signal. ctl eq 0 => break
+ * signal terminate ctl ne 0 => start break signal
+ */
+static void msm_hs_break_ctl(struct uart_port *uport, int ctl)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	clk_enable(msm_uport->clk);
+	msm_hs_write(uport, UARTDM_CR_ADDR, ctl ? START_BREAK : STOP_BREAK);
+	clk_disable(msm_uport->clk);
+}
+
+static void msm_hs_config_port(struct uart_port *uport, int cfg_flags)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&uport->lock, flags);
+	if (cfg_flags & UART_CONFIG_TYPE) {
+		uport->type = PORT_MSM;
+		msm_hs_request_port(uport);
+	}
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+/*  Handle CTS changes (Called from interrupt handler) */
+static void msm_hs_handle_delta_cts(struct uart_port *uport)
+{
+	unsigned long flags;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	spin_lock_irqsave(&uport->lock, flags);
+	clk_enable(msm_uport->clk);
+
+	/* clear interrupt */
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_CTS);
+	uport->icount.cts++;
+
+	clk_disable(msm_uport->clk);
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	/* clear the IOCTL TIOCMIWAIT if called */
+	wake_up_interruptible(&uport->state->port.delta_msr_wait);
+}
+
+/* check if the TX path is flushed, and if so clock off
+ * returns 0 did not clock off, need to retry (still sending final byte)
+ *        -1 did not clock off, do not retry
+ *         1 if we clocked off
+ */
+static int msm_hs_check_clock_off_locked(struct uart_port *uport)
+{
+	unsigned long sr_status;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+	struct circ_buf *tx_buf = &uport->state->xmit;
+
+	/* Cancel if tx tty buffer is not empty, dma is in flight,
+	 * or tx fifo is not empty, or rx fifo is not empty */
+	if (msm_uport->clk_state != MSM_HS_CLK_REQUEST_OFF ||
+	    !uart_circ_empty(tx_buf) || msm_uport->tx.dma_in_flight ||
+	    (msm_uport->imr_reg & UARTDM_ISR_TXLEV_BMSK) ||
+	    !(msm_uport->imr_reg & UARTDM_ISR_RXLEV_BMSK))  {
+		return -1;
+	}
+
+	/* Make sure the uart is finished with the last byte */
+	sr_status = msm_hs_read(uport, UARTDM_SR_ADDR);
+	if (!(sr_status & UARTDM_SR_TXEMT_BMSK))
+		return 0;  /* retry */
+
+	/* Make sure forced RXSTALE flush complete */
+	switch (msm_uport->clk_req_off_state) {
+	case CLK_REQ_OFF_START:
+		msm_uport->clk_req_off_state = CLK_REQ_OFF_RXSTALE_ISSUED;
+		msm_hs_write(uport, UARTDM_CR_ADDR, FORCE_STALE_EVENT);
+		return 0;  /* RXSTALE flush not complete - retry */
+	case CLK_REQ_OFF_RXSTALE_ISSUED:
+	case CLK_REQ_OFF_FLUSH_ISSUED:
+		return 0;  /* RXSTALE flush not complete - retry */
+	case CLK_REQ_OFF_RXSTALE_FLUSHED:
+		break;  /* continue */
+	}
+
+	if (msm_uport->rx.flush != FLUSH_SHUTDOWN) {
+		if (msm_uport->rx.flush == FLUSH_NONE)
+			msm_hs_stop_rx_locked(uport);
+		return 0;  /* come back later to really clock off */
+	}
+
+	/* we really want to clock off */
+	clk_disable(msm_uport->clk);
+	msm_uport->clk_state = MSM_HS_CLK_OFF;
+
+	if (use_low_power_rx_wakeup(msm_uport)) {
+		msm_uport->rx_wakeup.ignore = 1;
+		enable_irq(msm_uport->rx_wakeup.irq);
+	}
+	return 1;
+}
+
+static enum hrtimer_restart msm_hs_clk_off_retry(struct hrtimer *timer)
+{
+	unsigned long flags;
+	int ret = HRTIMER_NORESTART;
+	struct msm_hs_port *msm_uport = container_of(timer, struct msm_hs_port,
+						     clk_off_timer);
+	struct uart_port *uport = &msm_uport->uport;
+
+	spin_lock_irqsave(&uport->lock, flags);
+
+	if (!msm_hs_check_clock_off_locked(uport)) {
+		hrtimer_forward_now(timer, msm_uport->clk_off_delay);
+		ret = HRTIMER_RESTART;
+	}
+
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	return ret;
+}
+
+static irqreturn_t msm_hs_isr(int irq, void *dev)
+{
+	unsigned long flags;
+	unsigned long isr_status;
+	struct msm_hs_port *msm_uport = dev;
+	struct uart_port *uport = &msm_uport->uport;
+	struct circ_buf *tx_buf = &uport->state->xmit;
+	struct msm_hs_tx *tx = &msm_uport->tx;
+	struct msm_hs_rx *rx = &msm_uport->rx;
+
+	spin_lock_irqsave(&uport->lock, flags);
+
+	isr_status = msm_hs_read(uport, UARTDM_MISR_ADDR);
+
+	/* Uart RX starting */
+	if (isr_status & UARTDM_ISR_RXLEV_BMSK) {
+		msm_uport->imr_reg &= ~UARTDM_ISR_RXLEV_BMSK;
+		msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+	}
+	/* Stale rx interrupt */
+	if (isr_status & UARTDM_ISR_RXSTALE_BMSK) {
+		msm_hs_write(uport, UARTDM_CR_ADDR, STALE_EVENT_DISABLE);
+		msm_hs_write(uport, UARTDM_CR_ADDR, RESET_STALE_INT);
+
+		if (msm_uport->clk_req_off_state == CLK_REQ_OFF_RXSTALE_ISSUED)
+			msm_uport->clk_req_off_state =
+					CLK_REQ_OFF_FLUSH_ISSUED;
+		if (rx->flush == FLUSH_NONE) {
+			rx->flush = FLUSH_DATA_READY;
+			msm_dmov_stop_cmd(msm_uport->dma_rx_channel, NULL, 1);
+		}
+	}
+	/* tx ready interrupt */
+	if (isr_status & UARTDM_ISR_TX_READY_BMSK) {
+		/* Clear  TX Ready */
+		msm_hs_write(uport, UARTDM_CR_ADDR, CLEAR_TX_READY);
+
+		if (msm_uport->clk_state == MSM_HS_CLK_REQUEST_OFF) {
+			msm_uport->imr_reg |= UARTDM_ISR_TXLEV_BMSK;
+			msm_hs_write(uport, UARTDM_IMR_ADDR,
+				     msm_uport->imr_reg);
+		}
+
+		/* Complete DMA TX transactions and submit new transactions */
+		tx_buf->tail = (tx_buf->tail + tx->tx_count) & ~UART_XMIT_SIZE;
+
+		tx->dma_in_flight = 0;
+
+		uport->icount.tx += tx->tx_count;
+		if (tx->tx_ready_int_en)
+			msm_hs_submit_tx_locked(uport);
+
+		if (uart_circ_chars_pending(tx_buf) < WAKEUP_CHARS)
+			uart_write_wakeup(uport);
+	}
+	if (isr_status & UARTDM_ISR_TXLEV_BMSK) {
+		/* TX FIFO is empty */
+		msm_uport->imr_reg &= ~UARTDM_ISR_TXLEV_BMSK;
+		msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+		if (!msm_hs_check_clock_off_locked(uport))
+			hrtimer_start(&msm_uport->clk_off_timer,
+				      msm_uport->clk_off_delay,
+				      HRTIMER_MODE_REL);
+	}
+
+	/* Change in CTS interrupt */
+	if (isr_status & UARTDM_ISR_DELTA_CTS_BMSK)
+		msm_hs_handle_delta_cts(uport);
+
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+void msm_hs_request_clock_off_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	if (msm_uport->clk_state == MSM_HS_CLK_ON) {
+		msm_uport->clk_state = MSM_HS_CLK_REQUEST_OFF;
+		msm_uport->clk_req_off_state = CLK_REQ_OFF_START;
+		if (!use_low_power_rx_wakeup(msm_uport))
+			set_rfr_locked(uport, 0);
+		msm_uport->imr_reg |= UARTDM_ISR_TXLEV_BMSK;
+		msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+	}
+}
+
+/**
+ * msm_hs_request_clock_off - request to (i.e. asynchronously) turn off uart
+ * clock once pending TX is flushed and Rx DMA command is terminated.
+ * @uport: uart_port structure for the device instance.
+ *
+ * This functions puts the device into a partially active low power mode. It
+ * waits to complete all pending tx transactions, flushes ongoing Rx DMA
+ * command and terminates UART side Rx transaction, puts UART HW in non DMA
+ * mode and then clocks off the device. A client calls this when no UART
+ * data is expected. msm_request_clock_on() must be called before any further
+ * UART can be sent or received.
+ */
+void msm_hs_request_clock_off(struct uart_port *uport)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&uport->lock, flags);
+	msm_hs_request_clock_off_locked(uport);
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+void msm_hs_request_clock_on_locked(struct uart_port *uport)
+{
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+	unsigned int data;
+
+	switch (msm_uport->clk_state) {
+	case MSM_HS_CLK_OFF:
+		clk_enable(msm_uport->clk);
+		disable_irq_nosync(msm_uport->rx_wakeup.irq);
+		/* fall-through */
+	case MSM_HS_CLK_REQUEST_OFF:
+		if (msm_uport->rx.flush == FLUSH_STOP ||
+		    msm_uport->rx.flush == FLUSH_SHUTDOWN) {
+			msm_hs_write(uport, UARTDM_CR_ADDR, RESET_RX);
+			data = msm_hs_read(uport, UARTDM_DMEN_ADDR);
+			data |= UARTDM_RX_DM_EN_BMSK;
+			msm_hs_write(uport, UARTDM_DMEN_ADDR, data);
+		}
+		hrtimer_try_to_cancel(&msm_uport->clk_off_timer);
+		if (msm_uport->rx.flush == FLUSH_SHUTDOWN)
+			msm_hs_start_rx_locked(uport);
+		if (!use_low_power_rx_wakeup(msm_uport))
+			set_rfr_locked(uport, 1);
+		if (msm_uport->rx.flush == FLUSH_STOP)
+			msm_uport->rx.flush = FLUSH_IGNORE;
+		msm_uport->clk_state = MSM_HS_CLK_ON;
+		break;
+	case MSM_HS_CLK_ON:
+		break;
+	case MSM_HS_CLK_PORT_OFF:
+		break;
+	}
+}
+
+/**
+ * msm_hs_request_clock_on - Switch the device from partially active low
+ * power mode to fully active (i.e. clock on) mode.
+ * @uport: uart_port structure for the device.
+ *
+ * This function switches on the input clock, puts UART HW into DMA mode
+ * and enqueues an Rx DMA command if the device was in partially active
+ * mode. It has no effect if called with the device in inactive state.
+ */
+void msm_hs_request_clock_on(struct uart_port *uport)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&uport->lock, flags);
+	msm_hs_request_clock_on_locked(uport);
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+static irqreturn_t msm_hs_rx_wakeup_isr(int irq, void *dev)
+{
+	unsigned int wakeup = 0;
+	unsigned long flags;
+	struct msm_hs_port *msm_uport = dev;
+	struct uart_port *uport = &msm_uport->uport;
+	struct tty_struct *tty = NULL;
+
+	spin_lock_irqsave(&uport->lock, flags);
+	if (msm_uport->clk_state == MSM_HS_CLK_OFF) {
+		/* ignore the first irq - it is a pending irq that occured
+		 * before enable_irq() */
+		if (msm_uport->rx_wakeup.ignore)
+			msm_uport->rx_wakeup.ignore = 0;
+		else
+			wakeup = 1;
+	}
+
+	if (wakeup) {
+		/* the uart was clocked off during an rx, wake up and
+		 * optionally inject char into tty rx */
+		msm_hs_request_clock_on_locked(uport);
+		if (msm_uport->rx_wakeup.inject_rx) {
+			tty = uport->state->port.tty;
+			tty_insert_flip_char(tty,
+					     msm_uport->rx_wakeup.rx_to_inject,
+					     TTY_NORMAL);
+			queue_work(msm_hs_workqueue, &msm_uport->rx.tty_work);
+		}
+	}
+
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static const char *msm_hs_type(struct uart_port *port)
+{
+	return (port->type == PORT_MSM) ? "MSM_HS_UART" : NULL;
+}
+
+/* Called when port is opened */
+static int msm_hs_startup(struct uart_port *uport)
+{
+	int ret;
+	int rfr_level;
+	unsigned long flags;
+	unsigned int data;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+	struct circ_buf *tx_buf = &uport->state->xmit;
+	struct msm_hs_tx *tx = &msm_uport->tx;
+	struct msm_hs_rx *rx = &msm_uport->rx;
+
+	rfr_level = uport->fifosize;
+	if (rfr_level > 16)
+		rfr_level -= 16;
+
+	tx->dma_base = dma_map_single(uport->dev, tx_buf->buf, UART_XMIT_SIZE,
+				      DMA_TO_DEVICE);
+
+	/* do not let tty layer execute RX in global workqueue, use a
+	 * dedicated workqueue managed by this driver */
+	uport->state->port.tty->low_latency = 1;
+
+	/* turn on uart clk */
+	ret = msm_hs_init_clk_locked(uport);
+	if (unlikely(ret)) {
+		printk(KERN_ERR "Turning uartclk failed!\n");
+		goto err_msm_hs_init_clk;
+	}
+
+	/* Set auto RFR Level */
+	data = msm_hs_read(uport, UARTDM_MR1_ADDR);
+	data &= ~UARTDM_MR1_AUTO_RFR_LEVEL1_BMSK;
+	data &= ~UARTDM_MR1_AUTO_RFR_LEVEL0_BMSK;
+	data |= (UARTDM_MR1_AUTO_RFR_LEVEL1_BMSK & (rfr_level << 2));
+	data |= (UARTDM_MR1_AUTO_RFR_LEVEL0_BMSK & rfr_level);
+	msm_hs_write(uport, UARTDM_MR1_ADDR, data);
+
+	/* Make sure RXSTALE count is non-zero */
+	data = msm_hs_read(uport, UARTDM_IPR_ADDR);
+	if (!data) {
+		data |= 0x1f & UARTDM_IPR_STALE_LSB_BMSK;
+		msm_hs_write(uport, UARTDM_IPR_ADDR, data);
+	}
+
+	/* Enable Data Mover Mode */
+	data = UARTDM_TX_DM_EN_BMSK | UARTDM_RX_DM_EN_BMSK;
+	msm_hs_write(uport, UARTDM_DMEN_ADDR, data);
+
+	/* Reset TX */
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_TX);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_RX);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_ERROR_STATUS);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_BREAK_INT);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_STALE_INT);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RESET_CTS);
+	msm_hs_write(uport, UARTDM_CR_ADDR, RFR_LOW);
+	/* Turn on Uart Receiver */
+	msm_hs_write(uport, UARTDM_CR_ADDR, UARTDM_CR_RX_EN_BMSK);
+
+	/* Turn on Uart Transmitter */
+	msm_hs_write(uport, UARTDM_CR_ADDR, UARTDM_CR_TX_EN_BMSK);
+
+	/* Initialize the tx */
+	tx->tx_ready_int_en = 0;
+	tx->dma_in_flight = 0;
+
+	tx->xfer.complete_func = msm_hs_dmov_tx_callback;
+	tx->xfer.execute_func = NULL;
+
+	tx->command_ptr->cmd = CMD_LC |
+	    CMD_DST_CRCI(msm_uport->dma_tx_crci) | CMD_MODE_BOX;
+
+	tx->command_ptr->src_dst_len = (MSM_UARTDM_BURST_SIZE << 16)
+					   | (MSM_UARTDM_BURST_SIZE);
+
+	tx->command_ptr->row_offset = (MSM_UARTDM_BURST_SIZE << 16);
+
+	tx->command_ptr->dst_row_addr =
+	    msm_uport->uport.mapbase + UARTDM_TF_ADDR;
+
+
+	/* Turn on Uart Receive */
+	rx->xfer.complete_func = msm_hs_dmov_rx_callback;
+	rx->xfer.execute_func = NULL;
+
+	rx->command_ptr->cmd = CMD_LC |
+	    CMD_SRC_CRCI(msm_uport->dma_rx_crci) | CMD_MODE_BOX;
+
+	rx->command_ptr->src_dst_len = (MSM_UARTDM_BURST_SIZE << 16)
+					   | (MSM_UARTDM_BURST_SIZE);
+	rx->command_ptr->row_offset =  MSM_UARTDM_BURST_SIZE;
+	rx->command_ptr->src_row_addr = uport->mapbase + UARTDM_RF_ADDR;
+
+
+	msm_uport->imr_reg |= UARTDM_ISR_RXSTALE_BMSK;
+	/* Enable reading the current CTS, no harm even if CTS is ignored */
+	msm_uport->imr_reg |= UARTDM_ISR_CURRENT_CTS_BMSK;
+
+	msm_hs_write(uport, UARTDM_TFWR_ADDR, 0);  /* TXLEV on empty TX fifo */
+
+
+	ret = request_irq(uport->irq, msm_hs_isr, IRQF_TRIGGER_HIGH,
+			  "msm_hs_uart", msm_uport);
+	if (unlikely(ret)) {
+		printk(KERN_ERR "Request msm_hs_uart IRQ failed!\n");
+		goto err_request_irq;
+	}
+	if (use_low_power_rx_wakeup(msm_uport)) {
+		ret = request_irq(msm_uport->rx_wakeup.irq,
+				  msm_hs_rx_wakeup_isr,
+				  IRQF_TRIGGER_FALLING,
+				  "msm_hs_rx_wakeup", msm_uport);
+		if (unlikely(ret)) {
+			printk(KERN_ERR "Request msm_hs_rx_wakeup IRQ failed!\n");
+			free_irq(uport->irq, msm_uport);
+			goto err_request_irq;
+		}
+		disable_irq(msm_uport->rx_wakeup.irq);
+	}
+
+	spin_lock_irqsave(&uport->lock, flags);
+
+	msm_hs_write(uport, UARTDM_RFWR_ADDR, 0);
+	msm_hs_start_rx_locked(uport);
+
+	spin_unlock_irqrestore(&uport->lock, flags);
+	ret = pm_runtime_set_active(uport->dev);
+	if (ret)
+		dev_err(uport->dev, "set active error:%d\n", ret);
+	pm_runtime_enable(uport->dev);
+
+	return 0;
+
+err_request_irq:
+err_msm_hs_init_clk:
+	dma_unmap_single(uport->dev, tx->dma_base,
+				UART_XMIT_SIZE, DMA_TO_DEVICE);
+	return ret;
+}
+
+/* Initialize tx and rx data structures */
+static int __devinit uartdm_init_port(struct uart_port *uport)
+{
+	int ret = 0;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+	struct msm_hs_tx *tx = &msm_uport->tx;
+	struct msm_hs_rx *rx = &msm_uport->rx;
+
+	/* Allocate the command pointer. Needs to be 64 bit aligned */
+	tx->command_ptr = kmalloc(sizeof(dmov_box), GFP_KERNEL | __GFP_DMA);
+	if (!tx->command_ptr)
+		return -ENOMEM;
+
+	tx->command_ptr_ptr = kmalloc(sizeof(u32 *), GFP_KERNEL | __GFP_DMA);
+	if (!tx->command_ptr_ptr) {
+		ret = -ENOMEM;
+		goto err_tx_command_ptr_ptr;
+	}
+
+	tx->mapped_cmd_ptr = dma_map_single(uport->dev, tx->command_ptr,
+					    sizeof(dmov_box), DMA_TO_DEVICE);
+	tx->mapped_cmd_ptr_ptr = dma_map_single(uport->dev,
+						tx->command_ptr_ptr,
+						sizeof(u32 *), DMA_TO_DEVICE);
+	tx->xfer.cmdptr = DMOV_CMD_ADDR(tx->mapped_cmd_ptr_ptr);
+
+	init_waitqueue_head(&rx->wait);
+
+	rx->pool = dma_pool_create("rx_buffer_pool", uport->dev,
+				   UARTDM_RX_BUF_SIZE, 16, 0);
+	if (!rx->pool) {
+		pr_err("%s(): cannot allocate rx_buffer_pool", __func__);
+		ret = -ENOMEM;
+		goto err_dma_pool_create;
+	}
+
+	rx->buffer = dma_pool_alloc(rx->pool, GFP_KERNEL, &rx->rbuffer);
+	if (!rx->buffer) {
+		pr_err("%s(): cannot allocate rx->buffer", __func__);
+		ret = -ENOMEM;
+		goto err_dma_pool_alloc;
+	}
+
+	/* Allocate the command pointer. Needs to be 64 bit aligned */
+	rx->command_ptr = kmalloc(sizeof(dmov_box), GFP_KERNEL | __GFP_DMA);
+	if (!rx->command_ptr) {
+		pr_err("%s(): cannot allocate rx->command_ptr", __func__);
+		ret = -ENOMEM;
+		goto err_rx_command_ptr;
+	}
+
+	rx->command_ptr_ptr = kmalloc(sizeof(u32 *), GFP_KERNEL | __GFP_DMA);
+	if (!rx->command_ptr_ptr) {
+		pr_err("%s(): cannot allocate rx->command_ptr_ptr", __func__);
+		ret = -ENOMEM;
+		goto err_rx_command_ptr_ptr;
+	}
+
+	rx->command_ptr->num_rows = ((UARTDM_RX_BUF_SIZE >> 4) << 16) |
+					 (UARTDM_RX_BUF_SIZE >> 4);
+
+	rx->command_ptr->dst_row_addr = rx->rbuffer;
+
+	rx->mapped_cmd_ptr = dma_map_single(uport->dev, rx->command_ptr,
+					    sizeof(dmov_box), DMA_TO_DEVICE);
+
+	*rx->command_ptr_ptr = CMD_PTR_LP | DMOV_CMD_ADDR(rx->mapped_cmd_ptr);
+
+	rx->cmdptr_dmaaddr = dma_map_single(uport->dev, rx->command_ptr_ptr,
+					    sizeof(u32 *), DMA_TO_DEVICE);
+	rx->xfer.cmdptr = DMOV_CMD_ADDR(rx->cmdptr_dmaaddr);
+
+	INIT_WORK(&rx->tty_work, msm_hs_tty_flip_buffer_work);
+
+	return ret;
+
+err_rx_command_ptr_ptr:
+	kfree(rx->command_ptr);
+err_rx_command_ptr:
+	dma_pool_free(msm_uport->rx.pool, msm_uport->rx.buffer,
+						msm_uport->rx.rbuffer);
+err_dma_pool_alloc:
+	dma_pool_destroy(msm_uport->rx.pool);
+err_dma_pool_create:
+	dma_unmap_single(uport->dev, msm_uport->tx.mapped_cmd_ptr_ptr,
+				sizeof(u32 *), DMA_TO_DEVICE);
+	dma_unmap_single(uport->dev, msm_uport->tx.mapped_cmd_ptr,
+				sizeof(dmov_box), DMA_TO_DEVICE);
+	kfree(msm_uport->tx.command_ptr_ptr);
+err_tx_command_ptr_ptr:
+	kfree(msm_uport->tx.command_ptr);
+	return ret;
+}
+
+static int __devinit msm_hs_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct uart_port *uport;
+	struct msm_hs_port *msm_uport;
+	struct resource *resource;
+	const struct msm_serial_hs_platform_data *pdata =
+						pdev->dev.platform_data;
+
+	if (pdev->id < 0 || pdev->id >= UARTDM_NR) {
+		printk(KERN_ERR "Invalid plaform device ID = %d\n", pdev->id);
+		return -EINVAL;
+	}
+
+	msm_uport = &q_uart_port[pdev->id];
+	uport = &msm_uport->uport;
+
+	uport->dev = &pdev->dev;
+
+	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!resource))
+		return -ENXIO;
+
+	uport->mapbase = resource->start;
+	uport->irq = platform_get_irq(pdev, 0);
+	if (unlikely(uport->irq < 0))
+		return -ENXIO;
+
+	if (unlikely(set_irq_wake(uport->irq, 1)))
+		return -ENXIO;
+
+	if (pdata == NULL || pdata->rx_wakeup_irq < 0)
+		msm_uport->rx_wakeup.irq = -1;
+	else {
+		msm_uport->rx_wakeup.irq = pdata->rx_wakeup_irq;
+		msm_uport->rx_wakeup.ignore = 1;
+		msm_uport->rx_wakeup.inject_rx = pdata->inject_rx_on_wakeup;
+		msm_uport->rx_wakeup.rx_to_inject = pdata->rx_to_inject;
+
+		if (unlikely(msm_uport->rx_wakeup.irq < 0))
+			return -ENXIO;
+
+		if (unlikely(set_irq_wake(msm_uport->rx_wakeup.irq, 1)))
+			return -ENXIO;
+	}
+
+	if (pdata == NULL)
+		msm_uport->exit_lpm_cb = NULL;
+	else
+		msm_uport->exit_lpm_cb = pdata->exit_lpm_cb;
+
+	resource = platform_get_resource_byname(pdev, IORESOURCE_DMA,
+						"uartdm_channels");
+	if (unlikely(!resource))
+		return -ENXIO;
+
+	msm_uport->dma_tx_channel = resource->start;
+	msm_uport->dma_rx_channel = resource->end;
+
+	resource = platform_get_resource_byname(pdev, IORESOURCE_DMA,
+						"uartdm_crci");
+	if (unlikely(!resource))
+		return -ENXIO;
+
+	msm_uport->dma_tx_crci = resource->start;
+	msm_uport->dma_rx_crci = resource->end;
+
+	uport->iotype = UPIO_MEM;
+	uport->fifosize = UART_FIFOSIZE;
+	uport->ops = &msm_hs_ops;
+	uport->flags = UPF_BOOT_AUTOCONF;
+	uport->uartclk = UARTCLK;
+	msm_uport->imr_reg = 0x0;
+	msm_uport->clk = clk_get(&pdev->dev, "uartdm_clk");
+	if (IS_ERR(msm_uport->clk))
+		return PTR_ERR(msm_uport->clk);
+
+	ret = uartdm_init_port(uport);
+	if (unlikely(ret))
+		return ret;
+
+	msm_uport->clk_state = MSM_HS_CLK_PORT_OFF;
+	hrtimer_init(&msm_uport->clk_off_timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL);
+	msm_uport->clk_off_timer.function = msm_hs_clk_off_retry;
+	msm_uport->clk_off_delay = ktime_set(0, 1000000);  /* 1ms */
+
+	uport->line = pdev->id;
+	return uart_add_one_port(&msm_hs_driver, uport);
+}
+
+static int __init msm_serial_hs_init(void)
+{
+	int ret, i;
+
+	/* Init all UARTS as non-configured */
+	for (i = 0; i < UARTDM_NR; i++)
+		q_uart_port[i].uport.type = PORT_UNKNOWN;
+
+	msm_hs_workqueue = create_singlethread_workqueue("msm_serial_hs");
+	if (unlikely(!msm_hs_workqueue))
+		return -ENOMEM;
+
+	ret = uart_register_driver(&msm_hs_driver);
+	if (unlikely(ret)) {
+		printk(KERN_ERR "%s failed to load\n", __func__);
+		goto err_uart_register_driver;
+	}
+
+	ret = platform_driver_register(&msm_serial_hs_platform_driver);
+	if (ret) {
+		printk(KERN_ERR "%s failed to load\n", __func__);
+		goto err_platform_driver_register;
+	}
+
+	return ret;
+
+err_platform_driver_register:
+	uart_unregister_driver(&msm_hs_driver);
+err_uart_register_driver:
+	destroy_workqueue(msm_hs_workqueue);
+	return ret;
+}
+module_init(msm_serial_hs_init);
+
+/*
+ *  Called by the upper layer when port is closed.
+ *     - Disables the port
+ *     - Unhook the ISR
+ */
+static void msm_hs_shutdown(struct uart_port *uport)
+{
+	unsigned long flags;
+	struct msm_hs_port *msm_uport = UARTDM_TO_MSM(uport);
+
+	BUG_ON(msm_uport->rx.flush < FLUSH_STOP);
+
+	spin_lock_irqsave(&uport->lock, flags);
+	clk_enable(msm_uport->clk);
+
+	/* Disable the transmitter */
+	msm_hs_write(uport, UARTDM_CR_ADDR, UARTDM_CR_TX_DISABLE_BMSK);
+	/* Disable the receiver */
+	msm_hs_write(uport, UARTDM_CR_ADDR, UARTDM_CR_RX_DISABLE_BMSK);
+
+	pm_runtime_disable(uport->dev);
+	pm_runtime_set_suspended(uport->dev);
+
+	/* Free the interrupt */
+	free_irq(uport->irq, msm_uport);
+	if (use_low_power_rx_wakeup(msm_uport))
+		free_irq(msm_uport->rx_wakeup.irq, msm_uport);
+
+	msm_uport->imr_reg = 0;
+	msm_hs_write(uport, UARTDM_IMR_ADDR, msm_uport->imr_reg);
+
+	wait_event(msm_uport->rx.wait, msm_uport->rx.flush == FLUSH_SHUTDOWN);
+
+	clk_disable(msm_uport->clk);  /* to balance local clk_enable() */
+	if (msm_uport->clk_state != MSM_HS_CLK_OFF)
+		clk_disable(msm_uport->clk);  /* to balance clk_state */
+	msm_uport->clk_state = MSM_HS_CLK_PORT_OFF;
+
+	dma_unmap_single(uport->dev, msm_uport->tx.dma_base,
+			 UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	if (cancel_work_sync(&msm_uport->rx.tty_work))
+		msm_hs_tty_flip_buffer_work(&msm_uport->rx.tty_work);
+}
+
+static void __exit msm_serial_hs_exit(void)
+{
+	flush_workqueue(msm_hs_workqueue);
+	destroy_workqueue(msm_hs_workqueue);
+	platform_driver_unregister(&msm_serial_hs_platform_driver);
+	uart_unregister_driver(&msm_hs_driver);
+}
+module_exit(msm_serial_hs_exit);
+
+#ifdef CONFIG_PM_RUNTIME
+static int msm_hs_runtime_idle(struct device *dev)
+{
+	/*
+	 * returning success from idle results in runtime suspend to be
+	 * called
+	 */
+	return 0;
+}
+
+static int msm_hs_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct
+						    platform_device, dev);
+	struct msm_hs_port *msm_uport = &q_uart_port[pdev->id];
+
+	msm_hs_request_clock_on(&msm_uport->uport);
+	return 0;
+}
+
+static int msm_hs_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct
+						    platform_device, dev);
+	struct msm_hs_port *msm_uport = &q_uart_port[pdev->id];
+
+	msm_hs_request_clock_off(&msm_uport->uport);
+	return 0;
+}
+#else
+#define msm_hs_runtime_idle NULL
+#define msm_hs_runtime_resume NULL
+#define msm_hs_runtime_suspend NULL
+#endif
+
+static const struct dev_pm_ops msm_hs_dev_pm_ops = {
+	.runtime_suspend = msm_hs_runtime_suspend,
+	.runtime_resume  = msm_hs_runtime_resume,
+	.runtime_idle    = msm_hs_runtime_idle,
+};
+
+static struct platform_driver msm_serial_hs_platform_driver = {
+	.probe = msm_hs_probe,
+	.remove = __devexit_p(msm_hs_remove),
+	.driver = {
+		.name = "msm_serial_hs",
+		.owner = THIS_MODULE,
+		.pm   = &msm_hs_dev_pm_ops,
+	},
+};
+
+static struct uart_driver msm_hs_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "msm_serial_hs",
+	.dev_name = "ttyHS",
+	.nr = UARTDM_NR,
+	.cons = 0,
+};
+
+static struct uart_ops msm_hs_ops = {
+	.tx_empty = msm_hs_tx_empty,
+	.set_mctrl = msm_hs_set_mctrl_locked,
+	.get_mctrl = msm_hs_get_mctrl_locked,
+	.stop_tx = msm_hs_stop_tx_locked,
+	.start_tx = msm_hs_start_tx_locked,
+	.stop_rx = msm_hs_stop_rx_locked,
+	.enable_ms = msm_hs_enable_ms_locked,
+	.break_ctl = msm_hs_break_ctl,
+	.startup = msm_hs_startup,
+	.shutdown = msm_hs_shutdown,
+	.set_termios = msm_hs_set_termios,
+	.pm = msm_hs_pm,
+	.type = msm_hs_type,
+	.config_port = msm_hs_config_port,
+	.release_port = msm_hs_release_port,
+	.request_port = msm_hs_request_port,
+};
+
+MODULE_DESCRIPTION("High Speed UART Driver for the MSM chipset");
+MODULE_VERSION("1.2");
+MODULE_LICENSE("GPL v2");

include/linux/platform_data/msm_serial_hs.h

···
+/*
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Nick Pelly <[e-mail]>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __ASM_ARCH_MSM_SERIAL_HS_H
+#define __ASM_ARCH_MSM_SERIAL_HS_H
+
+#include <linux/serial_core.h>
+
+/* API to request the uart clock off or on for low power management
+ * Clients should call request_clock_off() when no uart data is expected,
+ * and must call request_clock_on() before any further uart data can be
+ * received. */
+extern void msm_hs_request_clock_off(struct uart_port *uport);
+extern void msm_hs_request_clock_on(struct uart_port *uport);
+
+/**
+ * struct msm_serial_hs_platform_data
+ * @rx_wakeup_irq: Rx activity irq
+ * @rx_to_inject: extra character to be inserted to Rx tty on wakeup
+ * @inject_rx: 1 = insert rx_to_inject. 0 = do not insert extra character
+ * @exit_lpm_cb: function called before every Tx transaction
+ *
+ * This is an optional structure required for UART Rx GPIO IRQ based
+ * wakeup from low power state. UART wakeup can be triggered by RX activity
+ * (using a wakeup GPIO on the UART RX pin). This should only be used if
+ * there is not a wakeup GPIO on the UART CTS, and the first RX byte is
+ * known (eg., with the Bluetooth Texas Instruments HCILL protocol),
+ * since the first RX byte will always be lost. RTS will be asserted even
+ * while the UART is clocked off in this mode of operation.
+ */
+struct msm_serial_hs_platform_data {
+	int rx_wakeup_irq;
+	unsigned char inject_rx_on_wakeup;
+	char rx_to_inject;
+	void (*exit_lpm_cb)(struct uart_port *);
+};
+
+#endif