msm_serial: serial driver for MSM7K onboard serial peripheral.

Signed-off-by: Brian Swetland <swetland@google.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 898 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 1132c5cae7ab..037c1e0b7c4c 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1320,6 +1320,16 @@ config SERIAL_SGI_IOC3
 	  If you have an SGI Altix with an IOC3 serial card,
 	  say Y or M.  Otherwise, say N.
 
+config SERIAL_MSM
+	bool "MSM on-chip serial port support"
+	depends on ARM && ARCH_MSM
+	select SERIAL_CORE
+
+config SERIAL_MSM_CONSOLE
+	bool "MSM serial console support"
+	depends on SERIAL_MSM=y
+	select SERIAL_CORE_CONSOLE
+
 config SERIAL_NETX
 	tristate "NetX serial port support"
 	depends on ARM && ARCH_NETX
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 45a8658f54d5..d5a29981c6c4 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o
 obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o
 obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
 obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
+obj-$(CONFIG_SERIAL_MSM) += msm_serial.o
 obj-$(CONFIG_SERIAL_NETX) += netx-serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
diff --git a/drivers/serial/msm_serial.c b/drivers/serial/msm_serial.c
new file mode 100644
index 000000000000..1a7c856f76f8
--- /dev/null
+++ b/drivers/serial/msm_serial.c
@@ -0,0 +1,767 @@
+/*
+ * drivers/serial/msm_serial.c - driver for msm7k serial device and console
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Author: Robert Love <rlove@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+# define SUPPORT_SYSRQ
+#endif
+
+#include <linux/hrtimer.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+
+#include "msm_serial.h"
+
+struct msm_port {
+	struct uart_port	uart;
+	char			name[16];
+	struct clk		*clk;
+	unsigned int		imr;
+};
+
+#define UART_TO_MSM(uart_port)	((struct msm_port *) uart_port)
+
+static inline void msm_write(struct uart_port *port, unsigned int val,
+			     unsigned int off)
+{
+	__raw_writel(val, port->membase + off);
+}
+
+static inline unsigned int msm_read(struct uart_port *port, unsigned int off)
+{
+	return __raw_readl(port->membase + off);
+}
+
+static void msm_stop_tx(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	msm_port->imr &= ~UART_IMR_TXLEV;
+	msm_write(port, msm_port->imr, UART_IMR);
+}
+
+static void msm_start_tx(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	msm_port->imr |= UART_IMR_TXLEV;
+	msm_write(port, msm_port->imr, UART_IMR);
+}
+
+static void msm_stop_rx(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE);
+	msm_write(port, msm_port->imr, UART_IMR);
+}
+
+static void msm_enable_ms(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	msm_port->imr |= UART_IMR_DELTA_CTS;
+	msm_write(port, msm_port->imr, UART_IMR);
+}
+
+static void handle_rx(struct uart_port *port)
+{
+	struct tty_struct *tty = port->info->port.tty;
+	unsigned int sr;
+
+	/*
+	 * Handle overrun. My understanding of the hardware is that overrun
+	 * is not tied to the RX buffer, so we handle the case out of band.
+	 */
+	if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) {
+		port->icount.overrun++;
+		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
+	}
+
+	/* and now the main RX loop */
+	while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) {
+		unsigned int c;
+		char flag = TTY_NORMAL;
+
+		c = msm_read(port, UART_RF);
+
+		if (sr & UART_SR_RX_BREAK) {
+			port->icount.brk++;
+			if (uart_handle_break(port))
+				continue;
+		} else if (sr & UART_SR_PAR_FRAME_ERR) {
+			port->icount.frame++;
+		} else {
+			port->icount.rx++;
+		}
+
+		/* Mask conditions we're ignorning. */
+		sr &= port->read_status_mask;
+
+		if (sr & UART_SR_RX_BREAK) {
+			flag = TTY_BREAK;
+		} else if (sr & UART_SR_PAR_FRAME_ERR) {
+			flag = TTY_FRAME;
+		}
+
+		if (!uart_handle_sysrq_char(port, c))
+			tty_insert_flip_char(tty, c, flag);
+	}
+
+	tty_flip_buffer_push(tty);
+}
+
+static void handle_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->info->xmit;
+	struct msm_port *msm_port = UART_TO_MSM(port);
+	int sent_tx;
+
+	if (port->x_char) {
+		msm_write(port, port->x_char, UART_TF);
+		port->icount.tx++;
+		port->x_char = 0;
+	}
+
+	while (msm_read(port, UART_SR) & UART_SR_TX_READY) {
+		if (uart_circ_empty(xmit)) {
+			/* disable tx interrupts */
+			msm_port->imr &= ~UART_IMR_TXLEV;
+			msm_write(port, msm_port->imr, UART_IMR);
+			break;
+		}
+
+		msm_write(port, xmit->buf[xmit->tail], UART_TF);
+
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		sent_tx = 1;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+}
+
+static void handle_delta_cts(struct uart_port *port)
+{
+	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
+	port->icount.cts++;
+	wake_up_interruptible(&port->info->delta_msr_wait);
+}
+
+static irqreturn_t msm_irq(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct msm_port *msm_port = UART_TO_MSM(port);
+	unsigned int misr;
+
+	spin_lock(&port->lock);
+	misr = msm_read(port, UART_MISR);
+	msm_write(port, 0, UART_IMR); /* disable interrupt */
+
+	if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE))
+		handle_rx(port);
+	if (misr & UART_IMR_TXLEV)
+		handle_tx(port);
+	if (misr & UART_IMR_DELTA_CTS)
+		handle_delta_cts(port);
+
+	msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */
+	spin_unlock(&port->lock);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int msm_tx_empty(struct uart_port *port)
+{
+	return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int msm_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS;
+}
+
+static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int mr;
+
+	mr = msm_read(port, UART_MR1);
+
+	if (!(mctrl & TIOCM_RTS)) {
+		mr &= ~UART_MR1_RX_RDY_CTL;
+		msm_write(port, mr, UART_MR1);
+		msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR);
+	} else {
+		mr |= UART_MR1_RX_RDY_CTL;
+		msm_write(port, mr, UART_MR1);
+	}
+}
+
+static void msm_break_ctl(struct uart_port *port, int break_ctl)
+{
+	if (break_ctl)
+		msm_write(port, UART_CR_CMD_START_BREAK, UART_CR);
+	else
+		msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR);
+}
+
+static void msm_set_baud_rate(struct uart_port *port, unsigned int baud)
+{
+	unsigned int baud_code, rxstale, watermark;
+
+	switch (baud) {
+	case 300:
+		baud_code = UART_CSR_300;
+		rxstale = 1;
+		break;
+	case 600:
+		baud_code = UART_CSR_600;
+		rxstale = 1;
+		break;
+	case 1200:
+		baud_code = UART_CSR_1200;
+		rxstale = 1;
+		break;
+	case 2400:
+		baud_code = UART_CSR_2400;
+		rxstale = 1;
+		break;
+	case 4800:
+		baud_code = UART_CSR_4800;
+		rxstale = 1;
+		break;
+	case 9600:
+		baud_code = UART_CSR_9600;
+		rxstale = 2;
+		break;
+	case 14400:
+		baud_code = UART_CSR_14400;
+		rxstale = 3;
+		break;
+	case 19200:
+		baud_code = UART_CSR_19200;
+		rxstale = 4;
+		break;
+	case 28800:
+		baud_code = UART_CSR_28800;
+		rxstale = 6;
+		break;
+	case 38400:
+		baud_code = UART_CSR_38400;
+		rxstale = 8;
+		break;
+	case 57600:
+		baud_code = UART_CSR_57600;
+		rxstale = 16;
+		break;
+	case 115200:
+	default:
+		baud_code = UART_CSR_115200;
+		rxstale = 31;
+		break;
+	}
+
+	msm_write(port, baud_code, UART_CSR);
+
+	/* RX stale watermark */
+	watermark = UART_IPR_STALE_LSB & rxstale;
+	watermark |= UART_IPR_RXSTALE_LAST;
+	watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2);
+	msm_write(port, watermark, UART_IPR);
+
+	/* set RX watermark */
+	watermark = (port->fifosize * 3) / 4;
+	msm_write(port, watermark, UART_RFWR);
+
+	/* set TX watermark */
+	msm_write(port, 10, UART_TFWR);
+}
+
+static void msm_reset(struct uart_port *port)
+{
+	/* reset everything */
+	msm_write(port, UART_CR_CMD_RESET_RX, UART_CR);
+	msm_write(port, UART_CR_CMD_RESET_TX, UART_CR);
+	msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR);
+	msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR);
+	msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR);
+	msm_write(port, UART_CR_CMD_SET_RFR, UART_CR);
+}
+
+static void msm_init_clock(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	clk_enable(msm_port->clk);
+
+	msm_write(port, 0xC0, UART_MREG);
+	msm_write(port, 0xB2, UART_NREG);
+	msm_write(port, 0x7D, UART_DREG);
+	msm_write(port, 0x1C, UART_MNDREG);
+}
+
+static int msm_startup(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+	unsigned int data, rfr_level;
+	int ret;
+
+	snprintf(msm_port->name, sizeof(msm_port->name),
+		 "msm_serial%d", port->line);
+
+	ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH,
+			  msm_port->name, port);
+	if (unlikely(ret))
+		return ret;
+
+	msm_init_clock(port);
+
+	if (likely(port->fifosize > 12))
+		rfr_level = port->fifosize - 12;
+	else
+		rfr_level = port->fifosize;
+
+	/* set automatic RFR level */
+	data = msm_read(port, UART_MR1);
+	data &= ~UART_MR1_AUTO_RFR_LEVEL1;
+	data &= ~UART_MR1_AUTO_RFR_LEVEL0;
+	data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2);
+	data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level;
+	msm_write(port, data, UART_MR1);
+
+	/* make sure that RXSTALE count is non-zero */
+	data = msm_read(port, UART_IPR);
+	if (unlikely(!data)) {
+		data |= UART_IPR_RXSTALE_LAST;
+		data |= UART_IPR_STALE_LSB;
+		msm_write(port, data, UART_IPR);
+	}
+
+	msm_reset(port);
+
+	msm_write(port, 0x05, UART_CR);	/* enable TX & RX */
+
+	/* turn on RX and CTS interrupts */
+	msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE |
+			UART_IMR_CURRENT_CTS;
+	msm_write(port, msm_port->imr, UART_IMR);
+
+	return 0;
+}
+
+static void msm_shutdown(struct uart_port *port)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	msm_port->imr = 0;
+	msm_write(port, 0, UART_IMR); /* disable interrupts */
+
+	clk_disable(msm_port->clk);
+
+	free_irq(port->irq, port);
+}
+
+static void msm_set_termios(struct uart_port *port, struct ktermios *termios,
+			    struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, mr;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* calculate and set baud rate */
+	baud = uart_get_baud_rate(port, termios, old, 300, 115200);
+	msm_set_baud_rate(port, baud);
+
+	/* calculate parity */
+	mr = msm_read(port, UART_MR2);
+	mr &= ~UART_MR2_PARITY_MODE;
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & PARODD)
+			mr |= UART_MR2_PARITY_MODE_ODD;
+		else if (termios->c_cflag & CMSPAR)
+			mr |= UART_MR2_PARITY_MODE_SPACE;
+		else
+			mr |= UART_MR2_PARITY_MODE_EVEN;
+	}
+
+	/* calculate bits per char */
+	mr &= ~UART_MR2_BITS_PER_CHAR;
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		mr |= UART_MR2_BITS_PER_CHAR_5;
+		break;
+	case CS6:
+		mr |= UART_MR2_BITS_PER_CHAR_6;
+		break;
+	case CS7:
+		mr |= UART_MR2_BITS_PER_CHAR_7;
+		break;
+	case CS8:
+	default:
+		mr |= UART_MR2_BITS_PER_CHAR_8;
+		break;
+	}
+
+	/* calculate stop bits */
+	mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO);
+	if (termios->c_cflag & CSTOPB)
+		mr |= UART_MR2_STOP_BIT_LEN_TWO;
+	else
+		mr |= UART_MR2_STOP_BIT_LEN_ONE;
+
+	/* set parity, bits per char, and stop bit */
+	msm_write(port, mr, UART_MR2);
+
+	/* calculate and set hardware flow control */
+	mr = msm_read(port, UART_MR1);
+	mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL);
+	if (termios->c_cflag & CRTSCTS) {
+		mr |= UART_MR1_CTS_CTL;
+		mr |= UART_MR1_RX_RDY_CTL;
+	}
+	msm_write(port, mr, UART_MR1);
+
+	/* Configure status bits to ignore based on termio flags. */
+	port->read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART_SR_PAR_FRAME_ERR;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		port->read_status_mask |= UART_SR_RX_BREAK;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *msm_type(struct uart_port *port)
+{
+	return "MSM";
+}
+
+static void msm_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *resource;
+	resource_size_t size;
+
+	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!resource))
+		return;
+	size = resource->end - resource->start + 1;
+
+	release_mem_region(port->mapbase, size);
+	iounmap(port->membase);
+	port->membase = NULL;
+}
+
+static int msm_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *resource;
+	resource_size_t size;
+
+	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!resource))
+		return -ENXIO;
+	size = resource->end - resource->start + 1;
+
+	if (unlikely(!request_mem_region(port->mapbase, size, "msm_serial")))
+		return -EBUSY;
+
+	port->membase = ioremap(port->mapbase, size);
+	if (!port->membase) {
+		release_mem_region(port->mapbase, size);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+static void msm_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_MSM;
+		msm_request_port(port);
+	}
+}
+
+static int msm_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM))
+		return -EINVAL;
+	if (unlikely(port->irq != ser->irq))
+		return -EINVAL;
+	return 0;
+}
+
+static void msm_power(struct uart_port *port, unsigned int state,
+		      unsigned int oldstate)
+{
+	struct msm_port *msm_port = UART_TO_MSM(port);
+
+	switch (state) {
+	case 0:
+		clk_enable(msm_port->clk);
+		break;
+	case 3:
+		clk_disable(msm_port->clk);
+		break;
+	default:
+		printk(KERN_ERR "msm_serial: Unknown PM state %d\n", state);
+	}
+}
+
+static struct uart_ops msm_uart_pops = {
+	.tx_empty = msm_tx_empty,
+	.set_mctrl = msm_set_mctrl,
+	.get_mctrl = msm_get_mctrl,
+	.stop_tx = msm_stop_tx,
+	.start_tx = msm_start_tx,
+	.stop_rx = msm_stop_rx,
+	.enable_ms = msm_enable_ms,
+	.break_ctl = msm_break_ctl,
+	.startup = msm_startup,
+	.shutdown = msm_shutdown,
+	.set_termios = msm_set_termios,
+	.type = msm_type,
+	.release_port = msm_release_port,
+	.request_port = msm_request_port,
+	.config_port = msm_config_port,
+	.verify_port = msm_verify_port,
+	.pm = msm_power,
+};
+
+static struct msm_port msm_uart_ports[] = {
+	{
+		.uart = {
+			.iotype = UPIO_MEM,
+			.ops = &msm_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.fifosize = 512,
+			.line = 0,
+		},
+	},
+	{
+		.uart = {
+			.iotype = UPIO_MEM,
+			.ops = &msm_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.fifosize = 512,
+			.line = 1,
+		},
+	},
+	{
+		.uart = {
+			.iotype = UPIO_MEM,
+			.ops = &msm_uart_pops,
+			.flags = UPF_BOOT_AUTOCONF,
+			.fifosize = 64,
+			.line = 2,
+		},
+	},
+};
+
+#define UART_NR	ARRAY_SIZE(msm_uart_ports)
+
+static inline struct uart_port *get_port_from_line(unsigned int line)
+{
+	return &msm_uart_ports[line].uart;
+}
+
+#ifdef CONFIG_SERIAL_MSM_CONSOLE
+
+static void msm_console_putchar(struct uart_port *port, int c)
+{
+	while (!(msm_read(port, UART_SR) & UART_SR_TX_READY))
+		;
+	msm_write(port, c, UART_TF);
+}
+
+static void msm_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	struct uart_port *port;
+	struct msm_port *msm_port;
+
+	BUG_ON(co->index < 0 || co->index >= UART_NR);
+
+	port = get_port_from_line(co->index);
+	msm_port = UART_TO_MSM(port);
+
+	spin_lock(&port->lock);
+	uart_console_write(port, s, count, msm_console_putchar);
+	spin_unlock(&port->lock);
+}
+
+static int __init msm_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud, flow, bits, parity;
+
+	if (unlikely(co->index >= UART_NR || co->index < 0))
+		return -ENXIO;
+
+	port = get_port_from_line(co->index);
+
+	if (unlikely(!port->membase))
+		return -ENXIO;
+
+	port->cons = co;
+
+	msm_init_clock(port);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	bits = 8;
+	parity = 'n';
+	flow = 'n';
+	msm_write(port, UART_MR2_BITS_PER_CHAR_8 | UART_MR2_STOP_BIT_LEN_ONE,
+		  UART_MR2);	/* 8N1 */
+
+	if (baud < 300 || baud > 115200)
+		baud = 115200;
+	msm_set_baud_rate(port, baud);
+
+	msm_reset(port);
+
+	printk(KERN_INFO "msm_serial: console setup on port #%d\n", port->line);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver msm_uart_driver;
+
+static struct console msm_console = {
+	.name = "ttyMSM",
+	.write = msm_console_write,
+	.device = uart_console_device,
+	.setup = msm_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &msm_uart_driver,
+};
+
+#define MSM_CONSOLE	(&msm_console)
+
+#else
+#define MSM_CONSOLE	NULL
+#endif
+
+static struct uart_driver msm_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = "msm_serial",
+	.dev_name = "ttyMSM",
+	.nr = UART_NR,
+	.cons = MSM_CONSOLE,
+};
+
+static int __init msm_serial_probe(struct platform_device *pdev)
+{
+	struct msm_port *msm_port;
+	struct resource *resource;
+	struct uart_port *port;
+
+	if (unlikely(pdev->id < 0 || pdev->id >= UART_NR))
+		return -ENXIO;
+
+	printk(KERN_INFO "msm_serial: detected port #%d\n", pdev->id);
+
+	port = get_port_from_line(pdev->id);
+	port->dev = &pdev->dev;
+	msm_port = UART_TO_MSM(port);
+
+	msm_port->clk = clk_get(&pdev->dev, "uart_clk");
+	if (unlikely(IS_ERR(msm_port->clk)))
+		return PTR_ERR(msm_port->clk);
+	port->uartclk = clk_get_rate(msm_port->clk);
+
+	resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!resource))
+		return -ENXIO;
+	port->mapbase = resource->start;
+
+	port->irq = platform_get_irq(pdev, 0);
+	if (unlikely(port->irq < 0))
+		return -ENXIO;
+
+	platform_set_drvdata(pdev, port);
+
+	return uart_add_one_port(&msm_uart_driver, port);
+}
+
+static int __devexit msm_serial_remove(struct platform_device *pdev)
+{
+	struct msm_port *msm_port = platform_get_drvdata(pdev);
+
+	clk_put(msm_port->clk);
+
+	return 0;
+}
+
+static struct platform_driver msm_platform_driver = {
+	.probe = msm_serial_probe,
+	.remove = msm_serial_remove,
+	.driver = {
+		.name = "msm_serial",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init msm_serial_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&msm_uart_driver);
+	if (unlikely(ret))
+		return ret;
+
+	ret = platform_driver_probe(&msm_platform_driver, msm_serial_probe);
+	if (unlikely(ret))
+		uart_unregister_driver(&msm_uart_driver);
+
+	printk(KERN_INFO "msm_serial: driver initialized\n");
+
+	return ret;
+}
+
+static void __exit msm_serial_exit(void)
+{
+#ifdef CONFIG_SERIAL_MSM_CONSOLE
+	unregister_console(&msm_console);
+#endif
+	platform_driver_unregister(&msm_platform_driver);
+	uart_unregister_driver(&msm_uart_driver);
+}
+
+module_init(msm_serial_init);
+module_exit(msm_serial_exit);
+
+MODULE_AUTHOR("Robert Love <rlove@google.com>");
+MODULE_DESCRIPTION("Driver for msm7x serial device");
+MODULE_LICENSE("GPL");
diff --git a/drivers/serial/msm_serial.h b/drivers/serial/msm_serial.h
new file mode 100644
index 000000000000..689f1fa0e84e
--- /dev/null
+++ b/drivers/serial/msm_serial.h
@@ -0,0 +1,117 @@
+/*
+ * drivers/serial/msm_serial.h
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Author: Robert Love <rlove@google.com>
+ *
+ * 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 __DRIVERS_SERIAL_MSM_SERIAL_H
+#define __DRIVERS_SERIAL_MSM_SERIAL_H
+
+#define UART_MR1			0x0000
+
+#define UART_MR1_AUTO_RFR_LEVEL0	0x3F
+#define UART_MR1_AUTO_RFR_LEVEL1	0x3FF00
+#define UART_MR1_RX_RDY_CTL    		(1 << 7)
+#define UART_MR1_CTS_CTL       		(1 << 6)
+
+#define UART_MR2			0x0004
+#define UART_MR2_ERROR_MODE		(1 << 6)
+#define UART_MR2_BITS_PER_CHAR		0x30
+#define UART_MR2_BITS_PER_CHAR_5	(0x0 << 4)
+#define UART_MR2_BITS_PER_CHAR_6	(0x1 << 4)
+#define UART_MR2_BITS_PER_CHAR_7	(0x2 << 4)
+#define UART_MR2_BITS_PER_CHAR_8	(0x3 << 4)
+#define UART_MR2_STOP_BIT_LEN_ONE	(0x1 << 2)
+#define UART_MR2_STOP_BIT_LEN_TWO	(0x3 << 2)
+#define UART_MR2_PARITY_MODE_NONE	0x0
+#define UART_MR2_PARITY_MODE_ODD	0x1
+#define UART_MR2_PARITY_MODE_EVEN	0x2
+#define UART_MR2_PARITY_MODE_SPACE	0x3
+#define UART_MR2_PARITY_MODE		0x3
+
+#define UART_CSR	0x0008
+#define UART_CSR_115200	0xFF
+#define UART_CSR_57600	0xEE
+#define UART_CSR_38400	0xDD
+#define UART_CSR_28800	0xCC
+#define UART_CSR_19200	0xBB
+#define UART_CSR_14400	0xAA
+#define UART_CSR_9600	0x99
+#define UART_CSR_4800	0x77
+#define UART_CSR_2400	0x55
+#define UART_CSR_1200	0x44
+#define UART_CSR_600	0x33
+#define UART_CSR_300	0x22
+
+#define UART_TF		0x000C
+
+#define UART_CR				0x0010
+#define UART_CR_CMD_NULL		(0 << 4)
+#define UART_CR_CMD_RESET_RX		(1 << 4)
+#define UART_CR_CMD_RESET_TX		(2 << 4)
+#define UART_CR_CMD_RESET_ERR		(3 << 4)
+#define UART_CR_CMD_RESET_BREAK_INT	(4 << 4)
+#define UART_CR_CMD_START_BREAK		(5 << 4)
+#define UART_CR_CMD_STOP_BREAK		(6 << 4)
+#define UART_CR_CMD_RESET_CTS		(7 << 4)
+#define UART_CR_CMD_PACKET_MODE		(9 << 4)
+#define UART_CR_CMD_MODE_RESET		(12 << 4)
+#define UART_CR_CMD_SET_RFR		(13 << 4)
+#define UART_CR_CMD_RESET_RFR		(14 << 4)
+#define UART_CR_TX_DISABLE		(1 << 3)
+#define UART_CR_TX_ENABLE		(1 << 3)
+#define UART_CR_RX_DISABLE		(1 << 3)
+#define UART_CR_RX_ENABLE		(1 << 3)
+
+#define UART_IMR		0x0014
+#define UART_IMR_TXLEV		(1 << 0)
+#define UART_IMR_RXSTALE	(1 << 3)
+#define UART_IMR_RXLEV		(1 << 4)
+#define UART_IMR_DELTA_CTS	(1 << 5)
+#define UART_IMR_CURRENT_CTS	(1 << 6)
+
+#define UART_IPR_RXSTALE_LAST		0x20
+#define UART_IPR_STALE_LSB		0x1F
+#define UART_IPR_STALE_TIMEOUT_MSB	0x3FF80
+
+#define UART_IPR	0x0018
+#define UART_TFWR	0x001C
+#define UART_RFWR	0x0020
+#define UART_HCR	0x0024
+
+#define UART_MREG		0x0028
+#define UART_NREG		0x002C
+#define UART_DREG		0x0030
+#define UART_MNDREG		0x0034
+#define UART_IRDA		0x0038
+#define UART_MISR_MODE		0x0040
+#define UART_MISR_RESET		0x0044
+#define UART_MISR_EXPORT	0x0048
+#define UART_MISR_VAL		0x004C
+#define UART_TEST_CTRL		0x0050
+
+#define UART_SR			0x0008
+#define UART_SR_HUNT_CHAR	(1 << 7)
+#define UART_SR_RX_BREAK	(1 << 6)
+#define UART_SR_PAR_FRAME_ERR	(1 << 5)
+#define UART_SR_OVERRUN		(1 << 4)
+#define UART_SR_TX_EMPTY	(1 << 3)
+#define UART_SR_TX_READY	(1 << 2)
+#define UART_SR_RX_FULL		(1 << 1)
+#define UART_SR_RX_READY	(1 << 0)
+
+#define UART_RF		0x000C
+#define UART_MISR	0x0010
+#define UART_ISR	0x0014
+
+#endif	/* __DRIVERS_SERIAL_MSM_SERIAL_H */
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 6fd80c4243f1..23d2fb051f97 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -171,6 +171,9 @@
 /* Timberdale UART */
 #define PORT_TIMBUART	87
 
+/* Qualcomm MSM SoCs */
+#define PORT_MSM	88
+
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>