serial: Add OMAP high-speed UART driver

This patch adds driver support for OMAP2/3/4 high speed UART.

The driver is made separate from 8250 driver as we cannot
over load 8250 driver with omap platform specific configuration for
features like DMA, it makes easier to implement features like DMA and
hardware flow control and software flow control configuration with
this driver as required for the omap-platform.
This patch involves only the core driver and its dependent.

Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

5 files changed, 1493 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
new file mode 100644
index 00000000000..0d6f076cf74
--- /dev/null
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -0,0 +1,129 @@
+/*
+ * Driver for OMAP-UART controller.
+ * Based on drivers/serial/8250.c
+ *
+ * Copyright (C) 2010 Texas Instruments.
+ *
+ * Authors:
+ *	Govindraj R	<govindraj.raja@ti.com>
+ *	Thara Gopinath	<thara@ti.com>
+ *
+ * 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.
+ */
+
+#ifndef __OMAP_SERIAL_H__
+#define __OMAP_SERIAL_H__
+
+#include <linux/serial_core.h>
+#include <linux/platform_device.h>
+
+#include <plat/control.h>
+#include <plat/mux.h>
+
+#define DRIVER_NAME	"omap-hsuart"
+
+/*
+ * Use tty device name as ttyO, [O -> OMAP]
+ * in bootargs we specify as console=ttyO0 if uart1
+ * is used as console uart.
+ */
+#define OMAP_SERIAL_NAME	"ttyO"
+
+#define OMAP_MDR1_DISABLE	0x07
+#define OMAP_MDR1_MODE13X	0x03
+#define OMAP_MDR1_MODE16X	0x00
+#define OMAP_MODE13X_SPEED	230400
+
+/*
+ * LCR = 0XBF: Switch to Configuration Mode B.
+ * In configuration mode b allow access
+ * to EFR,DLL,DLH.
+ * Reference OMAP TRM Chapter 17
+ * Section: 1.4.3 Mode Selection
+ */
+#define OMAP_UART_LCR_CONF_MDB	0XBF
+
+/* WER = 0x7F
+ * Enable module level wakeup in WER reg
+ */
+#define OMAP_UART_WER_MOD_WKUP	0X7F
+
+/* Enable XON/XOFF flow control on output */
+#define OMAP_UART_SW_TX		0x04
+
+/* Enable XON/XOFF flow control on input */
+#define OMAP_UART_SW_RX		0x04
+
+#define OMAP_UART_SYSC_RESET	0X07
+#define OMAP_UART_TCR_TRIG	0X0F
+#define OMAP_UART_SW_CLR	0XF0
+#define OMAP_UART_FIFO_CLR	0X06
+
+#define OMAP_UART_DMA_CH_FREE	-1
+
+#define RX_TIMEOUT		(3 * HZ)
+#define OMAP_MAX_HSUART_PORTS	4
+
+#define MSR_SAVE_FLAGS		UART_MSR_ANY_DELTA
+
+struct omap_uart_port_info {
+	bool			dma_enabled;	/* To specify DMA Mode */
+	unsigned int		uartclk;	/* UART clock rate */
+	void __iomem		*membase;	/* ioremap cookie or NULL */
+	resource_size_t		mapbase;	/* resource base */
+	unsigned long		irqflags;	/* request_irq flags */
+	upf_t			flags;		/* UPF_* flags */
+};
+
+struct uart_omap_dma {
+	u8			uart_dma_tx;
+	u8			uart_dma_rx;
+	int			rx_dma_channel;
+	int			tx_dma_channel;
+	dma_addr_t		rx_buf_dma_phys;
+	dma_addr_t		tx_buf_dma_phys;
+	unsigned int		uart_base;
+	/*
+	 * Buffer for rx dma.It is not required for tx because the buffer
+	 * comes from port structure.
+	 */
+	unsigned char		*rx_buf;
+	unsigned int		prev_rx_dma_pos;
+	int			tx_buf_size;
+	int			tx_dma_used;
+	int			rx_dma_used;
+	spinlock_t		tx_lock;
+	spinlock_t		rx_lock;
+	/* timer to poll activity on rx dma */
+	struct timer_list	rx_timer;
+	int			rx_buf_size;
+	int			rx_timeout;
+};
+
+struct uart_omap_port {
+	struct uart_port	port;
+	struct uart_omap_dma	uart_dma;
+	struct platform_device	*pdev;
+
+	unsigned char		ier;
+	unsigned char		lcr;
+	unsigned char		mcr;
+	unsigned char		fcr;
+	unsigned char		efr;
+
+	int			use_dma;
+	/*
+	 * Some bits in registers are cleared on a read, so they must
+	 * be saved whenever the register is read but the bits will not
+	 * be immediately processed.
+	 */
+	unsigned int		lsr_break_flag;
+	unsigned char		msr_saved_flags;
+	char			name[20];
+	unsigned long		port_activity;
+};
+
+#endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 12900f7083b..8d8b975ce78 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1416,6 +1416,33 @@ config SERIAL_OF_PLATFORM
 	  Currently, only 8250 compatible ports are supported, but
 	  others can easily be added.
 
+config SERIAL_OMAP
+	tristate "OMAP serial port support"
+	depends on ARCH_OMAP2 || ARCH_OMAP3 || ARCH_OMAP4
+	select SERIAL_CORE
+	help
+	  If you have a machine based on an Texas Instruments OMAP CPU you
+	  can enable its onboard serial ports by enabling this option.
+
+	  By enabling this option you take advantage of dma feature available
+	  with the omap-serial driver. DMA support can be enabled from platform
+	  data.
+
+config SERIAL_OMAP_CONSOLE
+	bool "Console on OMAP serial port"
+	depends on SERIAL_OMAP
+	select SERIAL_CORE_CONSOLE
+	help
+	  Select this option if you would like to use omap serial port as
+	  console.
+
+	  Even if you say Y here, the currently visible virtual console
+	  (/dev/tty0) will still be used as the system console by default, but
+	  you can alter that using a kernel command line option such as
+	  "console=ttyOx". (Try "man bootparam" or see the documentation of
+	  your boot loader about how to pass options to the kernel at
+	  boot time.)
+
 config SERIAL_OF_PLATFORM_NWPSERIAL
 	tristate "NWP serial port driver"
 	depends on PPC_OF && PPC_DCR
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 1ca4fd599ff..c5705765454 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -88,3 +88,4 @@ obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
 obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
 obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
+obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
diff --git a/drivers/serial/omap-serial.c b/drivers/serial/omap-serial.c
new file mode 100644
index 00000000000..2ee1d3282a8
--- /dev/null
+++ b/drivers/serial/omap-serial.c
@@ -0,0 +1,1333 @@
+/*
+ * Driver for OMAP-UART controller.
+ * Based on drivers/serial/8250.c
+ *
+ * Copyright (C) 2010 Texas Instruments.
+ *
+ * Authors:
+ *	Govindraj R	<govindraj.raja@ti.com>
+ *	Thara Gopinath	<thara@ti.com>
+ *
+ * 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.
+ *
+ * Note: This driver is made seperate from 8250 driver as we cannot
+ * over load 8250 driver with omap platform specific configuration for
+ * features like DMA, it makes easier to implement features like DMA and
+ * hardware flow control and software flow control configuration with
+ * this driver as required for the omap-platform.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/serial_reg.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/clk.h>
+#include <linux/serial_core.h>
+#include <linux/irq.h>
+
+#include <plat/dma.h>
+#include <plat/dmtimer.h>
+#include <plat/omap-serial.h>
+
+static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
+
+/* Forward declaration of functions */
+static void uart_tx_dma_callback(int lch, u16 ch_status, void *data);
+static void serial_omap_rx_timeout(unsigned long uart_no);
+static int serial_omap_start_rxdma(struct uart_omap_port *up);
+
+static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
+{
+	offset <<= up->port.regshift;
+	return readw(up->port.membase + offset);
+}
+
+static inline void serial_out(struct uart_omap_port *up, int offset, int value)
+{
+	offset <<= up->port.regshift;
+	writew(value, up->port.membase + offset);
+}
+
+static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
+{
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+		       UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_FCR, 0);
+}
+
+/*
+ * serial_omap_get_divisor - calculate divisor value
+ * @port: uart port info
+ * @baud: baudrate for which divisor needs to be calculated.
+ *
+ * We have written our own function to get the divisor so as to support
+ * 13x mode. 3Mbps Baudrate as an different divisor.
+ * Reference OMAP TRM Chapter 17:
+ * Table 17-1. UART Mode Baud Rates, Divisor Values, and Error Rates
+ * referring to oversampling - divisor value
+ * baudrate 460,800 to 3,686,400 all have divisor 13
+ * except 3,000,000 which has divisor value 16
+ */
+static unsigned int
+serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
+{
+	unsigned int divisor;
+
+	if (baud > OMAP_MODE13X_SPEED && baud != 3000000)
+		divisor = 13;
+	else
+		divisor = 16;
+	return port->uartclk/(baud * divisor);
+}
+
+static void serial_omap_stop_rxdma(struct uart_omap_port *up)
+{
+	if (up->uart_dma.rx_dma_used) {
+		del_timer(&up->uart_dma.rx_timer);
+		omap_stop_dma(up->uart_dma.rx_dma_channel);
+		omap_free_dma(up->uart_dma.rx_dma_channel);
+		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
+		up->uart_dma.rx_dma_used = false;
+	}
+}
+
+static void serial_omap_enable_ms(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+
+	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->pdev->id);
+	up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static void serial_omap_stop_tx(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+
+	if (up->use_dma &&
+		up->uart_dma.tx_dma_channel != OMAP_UART_DMA_CH_FREE) {
+		/*
+		 * Check if dma is still active. If yes do nothing,
+		 * return. Else stop dma
+		 */
+		if (omap_get_dma_active_status(up->uart_dma.tx_dma_channel))
+			return;
+		omap_stop_dma(up->uart_dma.tx_dma_channel);
+		omap_free_dma(up->uart_dma.tx_dma_channel);
+		up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
+	}
+
+	if (up->ier & UART_IER_THRI) {
+		up->ier &= ~UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static void serial_omap_stop_rx(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+
+	if (up->use_dma)
+		serial_omap_stop_rxdma(up);
+	up->ier &= ~UART_IER_RLSI;
+	up->port.read_status_mask &= ~UART_LSR_DR;
+	serial_out(up, UART_IER, up->ier);
+}
+
+static inline void receive_chars(struct uart_omap_port *up, int *status)
+{
+	struct tty_struct *tty = up->port.state->port.tty;
+	unsigned int flag;
+	unsigned char ch, lsr = *status;
+	int max_count = 256;
+
+	do {
+		if (likely(lsr & UART_LSR_DR))
+			ch = serial_in(up, UART_RX);
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
+			/*
+			 * For statistics only
+			 */
+			if (lsr & UART_LSR_BI) {
+				lsr &= ~(UART_LSR_FE | UART_LSR_PE);
+				up->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(&up->port))
+					goto ignore_char;
+			} else if (lsr & UART_LSR_PE) {
+				up->port.icount.parity++;
+			} else if (lsr & UART_LSR_FE) {
+				up->port.icount.frame++;
+			}
+
+			if (lsr & UART_LSR_OE)
+				up->port.icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ignored.
+			 */
+			lsr &= up->port.read_status_mask;
+
+#ifdef CONFIG_SERIAL_OMAP_CONSOLE
+			if (up->port.line == up->port.cons->index) {
+				/* Recover the break flag from console xmit */
+				lsr |= up->lsr_break_flag;
+				up->lsr_break_flag = 0;
+			}
+#endif
+			if (lsr & UART_LSR_BI)
+				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(&up->port, ch))
+			goto ignore_char;
+		uart_insert_char(&up->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(&up->port.lock);
+	tty_flip_buffer_push(tty);
+	spin_lock(&up->port.lock);
+}
+
+static void transmit_chars(struct uart_omap_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int count;
+
+	if (up->port.x_char) {
+		serial_out(up, UART_TX, up->port.x_char);
+		up->port.icount.tx++;
+		up->port.x_char = 0;
+		return;
+	}
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
+		serial_omap_stop_tx(&up->port);
+		return;
+	}
+	count = up->port.fifosize / 4;
+	do {
+		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		up->port.icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (uart_circ_empty(xmit))
+		serial_omap_stop_tx(&up->port);
+}
+
+static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
+{
+	if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static void serial_omap_start_tx(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	struct circ_buf *xmit;
+	unsigned int start;
+	int ret = 0;
+
+	if (!up->use_dma) {
+		serial_omap_enable_ier_thri(up);
+		return;
+	}
+
+	if (up->uart_dma.tx_dma_used)
+		return;
+
+	xmit = &up->port.state->xmit;
+
+	if (up->uart_dma.tx_dma_channel == OMAP_UART_DMA_CH_FREE) {
+		ret = omap_request_dma(up->uart_dma.uart_dma_tx,
+				"UART Tx DMA",
+				(void *)uart_tx_dma_callback, up,
+				&(up->uart_dma.tx_dma_channel));
+
+		if (ret < 0) {
+			serial_omap_enable_ier_thri(up);
+			return;
+		}
+	}
+	spin_lock(&(up->uart_dma.tx_lock));
+	up->uart_dma.tx_dma_used = true;
+	spin_unlock(&(up->uart_dma.tx_lock));
+
+	start = up->uart_dma.tx_buf_dma_phys +
+				(xmit->tail & (UART_XMIT_SIZE - 1));
+
+	up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit);
+	/*
+	 * It is a circular buffer. See if the buffer has wounded back.
+	 * If yes it will have to be transferred in two separate dma
+	 * transfers
+	 */
+	if (start + up->uart_dma.tx_buf_size >=
+			up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE)
+		up->uart_dma.tx_buf_size =
+			(up->uart_dma.tx_buf_dma_phys +
+			UART_XMIT_SIZE) - start;
+
+	omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0,
+				OMAP_DMA_AMODE_CONSTANT,
+				up->uart_dma.uart_base, 0, 0);
+	omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0,
+				OMAP_DMA_AMODE_POST_INC, start, 0, 0);
+	omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel,
+				OMAP_DMA_DATA_TYPE_S8,
+				up->uart_dma.tx_buf_size, 1,
+				OMAP_DMA_SYNC_ELEMENT,
+				up->uart_dma.uart_dma_tx, 0);
+	/* FIXME: Cache maintenance needed here? */
+	omap_start_dma(up->uart_dma.tx_dma_channel);
+}
+
+static unsigned int check_modem_status(struct uart_omap_port *up)
+{
+	unsigned int status;
+
+	status = serial_in(up, UART_MSR);
+	status |= up->msr_saved_flags;
+	up->msr_saved_flags = 0;
+	if ((status & UART_MSR_ANY_DELTA) == 0)
+		return status;
+
+	if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
+	    up->port.state != NULL) {
+		if (status & UART_MSR_TERI)
+			up->port.icount.rng++;
+		if (status & UART_MSR_DDSR)
+			up->port.icount.dsr++;
+		if (status & UART_MSR_DDCD)
+			uart_handle_dcd_change
+				(&up->port, status & UART_MSR_DCD);
+		if (status & UART_MSR_DCTS)
+			uart_handle_cts_change
+				(&up->port, status & UART_MSR_CTS);
+		wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+	}
+
+	return status;
+}
+
+/**
+ * serial_omap_irq() - This handles the interrupt from one port
+ * @irq: uart port irq number
+ * @dev_id: uart port info
+ */
+static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
+{
+	struct uart_omap_port *up = dev_id;
+	unsigned int iir, lsr;
+	unsigned long flags;
+
+	iir = serial_in(up, UART_IIR);
+	if (iir & UART_IIR_NO_INT)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	lsr = serial_in(up, UART_LSR);
+	if (iir & UART_IIR_RLSI) {
+		if (!up->use_dma) {
+			if (lsr & UART_LSR_DR)
+				receive_chars(up, &lsr);
+		} else {
+			up->ier &= ~(UART_IER_RDI | UART_IER_RLSI);
+			serial_out(up, UART_IER, up->ier);
+			if ((serial_omap_start_rxdma(up) != 0) &&
+					(lsr & UART_LSR_DR))
+				receive_chars(up, &lsr);
+		}
+	}
+
+	check_modem_status(up);
+	if ((lsr & UART_LSR_THRE) && (iir & UART_IIR_THRI))
+		transmit_chars(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	up->port_activity = jiffies;
+	return IRQ_HANDLED;
+}
+
+static unsigned int serial_omap_tx_empty(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned long flags = 0;
+	unsigned int ret = 0;
+
+	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->pdev->id);
+	spin_lock_irqsave(&up->port.lock, flags);
+	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return ret;
+}
+
+static unsigned int serial_omap_get_mctrl(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned char status;
+	unsigned int ret = 0;
+
+	status = check_modem_status(up);
+	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->pdev->id);
+
+	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;
+}
+
+static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned char mcr = 0;
+
+	dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->pdev->id);
+	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 |= up->mcr;
+	serial_out(up, UART_MCR, mcr);
+}
+
+static void serial_omap_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned long flags = 0;
+
+	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->pdev->id);
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_out(up, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int serial_omap_startup(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned long flags = 0;
+	int retval;
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
+				up->name, up);
+	if (retval)
+		return retval;
+
+	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->pdev->id);
+
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	serial_omap_clear_fifos(up);
+	/* For Hardware flow control */
+	serial_out(up, UART_MCR, UART_MCR_RTS);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) serial_in(up, UART_LSR);
+	if (serial_in(up, UART_LSR) & UART_LSR_DR)
+		(void) serial_in(up, UART_RX);
+	(void) serial_in(up, UART_IIR);
+	(void) serial_in(up, UART_MSR);
+
+	/*
+	 * Now, initialize the UART
+	 */
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
+	spin_lock_irqsave(&up->port.lock, flags);
+	/*
+	 * Most PC uarts need OUT2 raised to enable interrupts.
+	 */
+	up->port.mctrl |= TIOCM_OUT2;
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	up->msr_saved_flags = 0;
+	if (up->use_dma) {
+		free_page((unsigned long)up->port.state->xmit.buf);
+		up->port.state->xmit.buf = dma_alloc_coherent(NULL,
+			UART_XMIT_SIZE,
+			(dma_addr_t *)&(up->uart_dma.tx_buf_dma_phys),
+			0);
+		init_timer(&(up->uart_dma.rx_timer));
+		up->uart_dma.rx_timer.function = serial_omap_rx_timeout;
+		up->uart_dma.rx_timer.data = up->pdev->id;
+		/* Currently the buffer size is 4KB. Can increase it */
+		up->uart_dma.rx_buf = dma_alloc_coherent(NULL,
+			up->uart_dma.rx_buf_size,
+			(dma_addr_t *)&(up->uart_dma.rx_buf_dma_phys), 0);
+	}
+	/*
+	 * 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_out(up, UART_IER, up->ier);
+
+	up->port_activity = jiffies;
+	return 0;
+}
+
+static void serial_omap_shutdown(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned long flags = 0;
+
+	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->pdev->id);
+	/*
+	 * Disable interrupts from this port
+	 */
+	up->ier = 0;
+	serial_out(up, UART_IER, 0);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->port.mctrl &= ~TIOCM_OUT2;
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/*
+	 * Disable break condition and FIFOs
+	 */
+	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
+	serial_omap_clear_fifos(up);
+
+	/*
+	 * Read data port to reset things, and then free the irq
+	 */
+	if (serial_in(up, UART_LSR) & UART_LSR_DR)
+		(void) serial_in(up, UART_RX);
+	if (up->use_dma) {
+		dma_free_coherent(up->port.dev,
+			UART_XMIT_SIZE,	up->port.state->xmit.buf,
+			up->uart_dma.tx_buf_dma_phys);
+		up->port.state->xmit.buf = NULL;
+		serial_omap_stop_rx(port);
+		dma_free_coherent(up->port.dev,
+			up->uart_dma.rx_buf_size, up->uart_dma.rx_buf,
+			up->uart_dma.rx_buf_dma_phys);
+		up->uart_dma.rx_buf = NULL;
+	}
+	free_irq(up->port.irq, up);
+}
+
+static inline void
+serial_omap_configure_xonxoff
+		(struct uart_omap_port *up, struct ktermios *termios)
+{
+	unsigned char efr = 0;
+
+	up->lcr = serial_in(up, UART_LCR);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+	up->efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB);
+
+	serial_out(up, UART_XON1, termios->c_cc[VSTART]);
+	serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
+
+	/* clear SW control mode bits */
+	efr = up->efr;
+	efr &= OMAP_UART_SW_CLR;
+
+	/*
+	 * IXON Flag:
+	 * Enable XON/XOFF flow control on output.
+	 * Transmit XON1, XOFF1
+	 */
+	if (termios->c_iflag & IXON)
+		efr |= OMAP_UART_SW_TX;
+
+	/*
+	 * IXOFF Flag:
+	 * Enable XON/XOFF flow control on input.
+	 * Receiver compares XON1, XOFF1.
+	 */
+	if (termios->c_iflag & IXOFF)
+		efr |= OMAP_UART_SW_RX;
+
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+	serial_out(up, UART_LCR, UART_LCR_DLAB);
+
+	up->mcr = serial_in(up, UART_MCR);
+
+	/*
+	 * IXANY Flag:
+	 * Enable any character to restart output.
+	 * Operation resumes after receiving any
+	 * character after recognition of the XOFF character
+	 */
+	if (termios->c_iflag & IXANY)
+		up->mcr |= UART_MCR_XONANY;
+
+	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+	serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
+	/* Enable special char function UARTi.EFR_REG[5] and
+	 * load the new software flow control mode IXON or IXOFF
+	 * and restore the UARTi.EFR_REG[4] ENHANCED_EN value.
+	 */
+	serial_out(up, UART_EFR, efr | UART_EFR_SCD);
+	serial_out(up, UART_LCR, UART_LCR_DLAB);
+
+	serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR);
+	serial_out(up, UART_LCR, up->lcr);
+}
+
+static void
+serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
+			struct ktermios *old)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned char cval = 0;
+	unsigned char efr = 0;
+	unsigned long flags = 0;
+	unsigned int baud, quot;
+
+	switch (termios->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 (termios->c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (termios->c_cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(termios->c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
+	quot = serial_omap_get_divisor(port, baud);
+
+	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
+			UART_FCR_ENABLE_FIFO;
+	if (up->use_dma)
+		up->fcr |= UART_FCR_DMA_SELECT;
+
+	/*
+	 * Ok, we're now changing the port state. Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		up->port.read_status_mask |= UART_LSR_BI;
+
+	/*
+	 * Characters to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		up->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)
+			up->port.ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * Modem status interrupts
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+	serial_out(up, UART_LCR, cval);		/* reset DLAB */
+
+	/* FIFOs and DMA Settings */
+
+	/* FCR can be changed only when the
+	 * baud clock is not running
+	 * DLL_REG and DLH_REG set to 0.
+	 */
+	serial_out(up, UART_LCR, UART_LCR_DLAB);
+	serial_out(up, UART_DLL, 0);
+	serial_out(up, UART_DLM, 0);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+
+	up->efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+
+	serial_out(up, UART_LCR, UART_LCR_DLAB);
+	up->mcr = serial_in(up, UART_MCR);
+	serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+	/* FIFO ENABLE, DMA MODE */
+	serial_out(up, UART_FCR, up->fcr);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+
+	if (up->use_dma) {
+		serial_out(up, UART_TI752_TLR, 0);
+		serial_out(up, UART_OMAP_SCR,
+			(UART_FCR_TRIGGER_4 | UART_FCR_TRIGGER_8));
+	}
+
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, UART_LCR_DLAB);
+	serial_out(up, UART_MCR, up->mcr);
+
+	/* Protocol, Baud Rate, and Interrupt Settings */
+
+	serial_out(up, UART_OMAP_MDR1, OMAP_MDR1_DISABLE);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+
+	up->efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+
+	serial_out(up, UART_LCR, 0);
+	serial_out(up, UART_IER, 0);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+
+	serial_out(up, UART_DLL, quot & 0xff);          /* LS of divisor */
+	serial_out(up, UART_DLM, quot >> 8);            /* MS of divisor */
+
+	serial_out(up, UART_LCR, 0);
+	serial_out(up, UART_IER, up->ier);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+
+	serial_out(up, UART_EFR, up->efr);
+	serial_out(up, UART_LCR, cval);
+
+	if (baud > 230400 && baud != 3000000)
+		serial_out(up, UART_OMAP_MDR1, OMAP_MDR1_MODE13X);
+	else
+		serial_out(up, UART_OMAP_MDR1, OMAP_MDR1_MODE16X);
+
+	/* Hardware Flow Control Configuration */
+
+	if (termios->c_cflag & CRTSCTS) {
+		efr |= (UART_EFR_CTS | UART_EFR_RTS);
+		serial_out(up, UART_LCR, UART_LCR_DLAB);
+
+		up->mcr = serial_in(up, UART_MCR);
+		serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
+
+		serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+		up->efr = serial_in(up, UART_EFR);
+		serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
+
+		serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
+		serial_out(up, UART_EFR, efr); /* Enable AUTORTS and AUTOCTS */
+		serial_out(up, UART_LCR, UART_LCR_DLAB);
+		serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS);
+		serial_out(up, UART_LCR, cval);
+	}
+
+	serial_omap_set_mctrl(&up->port, up->port.mctrl);
+	/* Software Flow Control Configuration */
+	if (termios->c_iflag & (IXON | IXOFF))
+		serial_omap_configure_xonxoff(up, termios);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->pdev->id);
+}
+
+static void
+serial_omap_pm(struct uart_port *port, unsigned int state,
+	       unsigned int oldstate)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+	unsigned char efr;
+
+	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->pdev->id);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+	efr = serial_in(up, UART_EFR);
+	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
+	serial_out(up, UART_LCR, 0);
+
+	serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
+	serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB);
+	serial_out(up, UART_EFR, efr);
+	serial_out(up, UART_LCR, 0);
+	/* Enable module level wake up */
+	serial_out(up, UART_OMAP_WER,
+		(state != 0) ? OMAP_UART_WER_MOD_WKUP : 0);
+}
+
+static void serial_omap_release_port(struct uart_port *port)
+{
+	dev_dbg(port->dev, "serial_omap_release_port+\n");
+}
+
+static int serial_omap_request_port(struct uart_port *port)
+{
+	dev_dbg(port->dev, "serial_omap_request_port+\n");
+	return 0;
+}
+
+static void serial_omap_config_port(struct uart_port *port, int flags)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+
+	dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
+							up->pdev->id);
+	up->port.type = PORT_OMAP;
+}
+
+static int
+serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* we don't want the core code to modify any port params */
+	dev_dbg(port->dev, "serial_omap_verify_port+\n");
+	return -EINVAL;
+}
+
+static const char *
+serial_omap_type(struct uart_port *port)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+
+	dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->pdev->id);
+	return up->name;
+}
+
+#ifdef CONFIG_SERIAL_OMAP_CONSOLE
+
+static struct uart_omap_port *serial_omap_console_ports[4];
+
+static struct uart_driver serial_omap_reg;
+
+#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
+
+static inline void wait_for_xmitr(struct uart_omap_port *up)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	do {
+		status = serial_in(up, UART_LSR);
+
+		if (status & UART_LSR_BI)
+			up->lsr_break_flag = UART_LSR_BI;
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		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);
+		}
+	}
+}
+
+static void serial_omap_console_putchar(struct uart_port *port, int ch)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)port;
+
+	wait_for_xmitr(up);
+	serial_out(up, UART_TX, ch);
+}
+
+static void
+serial_omap_console_write(struct console *co, const char *s,
+		unsigned int count)
+{
+	struct uart_omap_port *up = serial_omap_console_ports[co->index];
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	local_irq_save(flags);
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&up->port.lock);
+	else
+		spin_lock(&up->port.lock);
+
+	/*
+	 * First save the IER then disable the interrupts
+	 */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, 0);
+
+	uart_console_write(&up->port, s, count, serial_omap_console_putchar);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, 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)
+		check_modem_status(up);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+	local_irq_restore(flags);
+}
+
+static int __init
+serial_omap_console_setup(struct console *co, char *options)
+{
+	struct uart_omap_port *up;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (serial_omap_console_ports[co->index] == NULL)
+		return -ENODEV;
+	up = serial_omap_console_ports[co->index];
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&up->port, co, baud, parity, bits, flow);
+}
+
+static struct console serial_omap_console = {
+	.name		= OMAP_SERIAL_NAME,
+	.write		= serial_omap_console_write,
+	.device		= uart_console_device,
+	.setup		= serial_omap_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial_omap_reg,
+};
+
+static void serial_omap_add_console_port(struct uart_omap_port *up)
+{
+	serial_omap_console_ports[up->pdev->id] = up;
+}
+
+#define OMAP_CONSOLE	(&serial_omap_console)
+
+#else
+
+#define OMAP_CONSOLE	NULL
+
+static inline void serial_omap_add_console_port(struct uart_omap_port *up)
+{}
+
+#endif
+
+static struct uart_ops serial_omap_pops = {
+	.tx_empty	= serial_omap_tx_empty,
+	.set_mctrl	= serial_omap_set_mctrl,
+	.get_mctrl	= serial_omap_get_mctrl,
+	.stop_tx	= serial_omap_stop_tx,
+	.start_tx	= serial_omap_start_tx,
+	.stop_rx	= serial_omap_stop_rx,
+	.enable_ms	= serial_omap_enable_ms,
+	.break_ctl	= serial_omap_break_ctl,
+	.startup	= serial_omap_startup,
+	.shutdown	= serial_omap_shutdown,
+	.set_termios	= serial_omap_set_termios,
+	.pm		= serial_omap_pm,
+	.type		= serial_omap_type,
+	.release_port	= serial_omap_release_port,
+	.request_port	= serial_omap_request_port,
+	.config_port	= serial_omap_config_port,
+	.verify_port	= serial_omap_verify_port,
+};
+
+static struct uart_driver serial_omap_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "OMAP-SERIAL",
+	.dev_name	= OMAP_SERIAL_NAME,
+	.nr		= OMAP_MAX_HSUART_PORTS,
+	.cons		= OMAP_CONSOLE,
+};
+
+static int
+serial_omap_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct uart_omap_port *up = platform_get_drvdata(pdev);
+
+	if (up)
+		uart_suspend_port(&serial_omap_reg, &up->port);
+	return 0;
+}
+
+static int serial_omap_resume(struct platform_device *dev)
+{
+	struct uart_omap_port *up = platform_get_drvdata(dev);
+
+	if (up)
+		uart_resume_port(&serial_omap_reg, &up->port);
+	return 0;
+}
+
+static void serial_omap_rx_timeout(unsigned long uart_no)
+{
+	struct uart_omap_port *up = ui[uart_no];
+	unsigned int curr_dma_pos, curr_transmitted_size;
+	unsigned int ret = 0;
+
+	curr_dma_pos = omap_get_dma_dst_pos(up->uart_dma.rx_dma_channel);
+	if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) ||
+			     (curr_dma_pos == 0)) {
+		if (jiffies_to_msecs(jiffies - up->port_activity) <
+							RX_TIMEOUT) {
+			mod_timer(&up->uart_dma.rx_timer, jiffies +
+				usecs_to_jiffies(up->uart_dma.rx_timeout));
+		} else {
+			serial_omap_stop_rxdma(up);
+			up->ier |= (UART_IER_RDI | UART_IER_RLSI);
+			serial_out(up, UART_IER, up->ier);
+		}
+		return;
+	}
+
+	curr_transmitted_size = curr_dma_pos -
+					up->uart_dma.prev_rx_dma_pos;
+	up->port.icount.rx += curr_transmitted_size;
+	tty_insert_flip_string(up->port.state->port.tty,
+			up->uart_dma.rx_buf +
+			(up->uart_dma.prev_rx_dma_pos -
+			up->uart_dma.rx_buf_dma_phys),
+			curr_transmitted_size);
+	tty_flip_buffer_push(up->port.state->port.tty);
+	up->uart_dma.prev_rx_dma_pos = curr_dma_pos;
+	if (up->uart_dma.rx_buf_size +
+			up->uart_dma.rx_buf_dma_phys == curr_dma_pos) {
+		ret = serial_omap_start_rxdma(up);
+		if (ret < 0) {
+			serial_omap_stop_rxdma(up);
+			up->ier |= (UART_IER_RDI | UART_IER_RLSI);
+			serial_out(up, UART_IER, up->ier);
+		}
+	} else  {
+		mod_timer(&up->uart_dma.rx_timer, jiffies +
+			usecs_to_jiffies(up->uart_dma.rx_timeout));
+	}
+	up->port_activity = jiffies;
+}
+
+static void uart_rx_dma_callback(int lch, u16 ch_status, void *data)
+{
+	return;
+}
+
+static int serial_omap_start_rxdma(struct uart_omap_port *up)
+{
+	int ret = 0;
+
+	if (up->uart_dma.rx_dma_channel == -1) {
+		ret = omap_request_dma(up->uart_dma.uart_dma_rx,
+				"UART Rx DMA",
+				(void *)uart_rx_dma_callback, up,
+				&(up->uart_dma.rx_dma_channel));
+		if (ret < 0)
+			return ret;
+
+		omap_set_dma_src_params(up->uart_dma.rx_dma_channel, 0,
+				OMAP_DMA_AMODE_CONSTANT,
+				up->uart_dma.uart_base, 0, 0);
+		omap_set_dma_dest_params(up->uart_dma.rx_dma_channel, 0,
+				OMAP_DMA_AMODE_POST_INC,
+				up->uart_dma.rx_buf_dma_phys, 0, 0);
+		omap_set_dma_transfer_params(up->uart_dma.rx_dma_channel,
+				OMAP_DMA_DATA_TYPE_S8,
+				up->uart_dma.rx_buf_size, 1,
+				OMAP_DMA_SYNC_ELEMENT,
+				up->uart_dma.uart_dma_rx, 0);
+	}
+	up->uart_dma.prev_rx_dma_pos = up->uart_dma.rx_buf_dma_phys;
+	/* FIXME: Cache maintenance needed here? */
+	omap_start_dma(up->uart_dma.rx_dma_channel);
+	mod_timer(&up->uart_dma.rx_timer, jiffies +
+				usecs_to_jiffies(up->uart_dma.rx_timeout));
+	up->uart_dma.rx_dma_used = true;
+	return ret;
+}
+
+static void serial_omap_continue_tx(struct uart_omap_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	unsigned int start = up->uart_dma.tx_buf_dma_phys
+			+ (xmit->tail & (UART_XMIT_SIZE - 1));
+
+	if (uart_circ_empty(xmit))
+		return;
+
+	up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit);
+	/*
+	 * It is a circular buffer. See if the buffer has wounded back.
+	 * If yes it will have to be transferred in two separate dma
+	 * transfers
+	 */
+	if (start + up->uart_dma.tx_buf_size >=
+			up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE)
+		up->uart_dma.tx_buf_size =
+			(up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE) - start;
+	omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0,
+				OMAP_DMA_AMODE_CONSTANT,
+				up->uart_dma.uart_base, 0, 0);
+	omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0,
+				OMAP_DMA_AMODE_POST_INC, start, 0, 0);
+	omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel,
+				OMAP_DMA_DATA_TYPE_S8,
+				up->uart_dma.tx_buf_size, 1,
+				OMAP_DMA_SYNC_ELEMENT,
+				up->uart_dma.uart_dma_tx, 0);
+	/* FIXME: Cache maintenance needed here? */
+	omap_start_dma(up->uart_dma.tx_dma_channel);
+}
+
+static void uart_tx_dma_callback(int lch, u16 ch_status, void *data)
+{
+	struct uart_omap_port *up = (struct uart_omap_port *)data;
+	struct circ_buf *xmit = &up->port.state->xmit;
+
+	xmit->tail = (xmit->tail + up->uart_dma.tx_buf_size) & \
+			(UART_XMIT_SIZE - 1);
+	up->port.icount.tx += up->uart_dma.tx_buf_size;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (uart_circ_empty(xmit)) {
+		spin_lock(&(up->uart_dma.tx_lock));
+		serial_omap_stop_tx(&up->port);
+		up->uart_dma.tx_dma_used = false;
+		spin_unlock(&(up->uart_dma.tx_lock));
+	} else {
+		omap_stop_dma(up->uart_dma.tx_dma_channel);
+		serial_omap_continue_tx(up);
+	}
+	up->port_activity = jiffies;
+	return;
+}
+
+static int serial_omap_probe(struct platform_device *pdev)
+{
+	struct uart_omap_port	*up;
+	struct resource		*mem, *irq, *dma_tx, *dma_rx;
+	struct omap_uart_port_info *omap_up_info = pdev->dev.platform_data;
+	int ret = -ENOSPC;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "no mem resource?\n");
+		return -ENODEV;
+	}
+
+	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!irq) {
+		dev_err(&pdev->dev, "no irq resource?\n");
+		return -ENODEV;
+	}
+
+	if (!request_mem_region(mem->start, (mem->end - mem->start) + 1,
+				     pdev->dev.driver->name)) {
+		dev_err(&pdev->dev, "memory region already claimed\n");
+		return -EBUSY;
+	}
+
+	dma_rx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx");
+	if (!dma_rx) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	dma_tx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx");
+	if (!dma_tx) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	up = kzalloc(sizeof(*up), GFP_KERNEL);
+	if (up == NULL) {
+		ret = -ENOMEM;
+		goto do_release_region;
+	}
+	sprintf(up->name, "OMAP UART%d", pdev->id);
+	up->pdev = pdev;
+	up->port.dev = &pdev->dev;
+	up->port.type = PORT_OMAP;
+	up->port.iotype = UPIO_MEM;
+	up->port.irq = irq->start;
+
+	up->port.regshift = 2;
+	up->port.fifosize = 64;
+	up->port.ops = &serial_omap_pops;
+	up->port.line = pdev->id;
+
+	up->port.membase = omap_up_info->membase;
+	up->port.mapbase = omap_up_info->mapbase;
+	up->port.flags = omap_up_info->flags;
+	up->port.irqflags = omap_up_info->irqflags;
+	up->port.uartclk = omap_up_info->uartclk;
+	up->uart_dma.uart_base = mem->start;
+
+	if (omap_up_info->dma_enabled) {
+		up->uart_dma.uart_dma_tx = dma_tx->start;
+		up->uart_dma.uart_dma_rx = dma_rx->start;
+		up->use_dma = 1;
+		up->uart_dma.rx_buf_size = 4096;
+		up->uart_dma.rx_timeout = 2;
+		spin_lock_init(&(up->uart_dma.tx_lock));
+		spin_lock_init(&(up->uart_dma.rx_lock));
+		up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
+		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
+	}
+
+	ui[pdev->id] = up;
+	serial_omap_add_console_port(up);
+
+	ret = uart_add_one_port(&serial_omap_reg, &up->port);
+	if (ret != 0)
+		goto do_release_region;
+
+	platform_set_drvdata(pdev, up);
+	return 0;
+err:
+	dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n",
+				pdev->id, __func__, ret);
+do_release_region:
+	release_mem_region(mem->start, (mem->end - mem->start) + 1);
+	return ret;
+}
+
+static int serial_omap_remove(struct platform_device *dev)
+{
+	struct uart_omap_port *up = platform_get_drvdata(dev);
+
+	platform_set_drvdata(dev, NULL);
+	if (up) {
+		uart_remove_one_port(&serial_omap_reg, &up->port);
+		kfree(up);
+	}
+	return 0;
+}
+
+static struct platform_driver serial_omap_driver = {
+	.probe          = serial_omap_probe,
+	.remove         = serial_omap_remove,
+
+	.suspend	= serial_omap_suspend,
+	.resume		= serial_omap_resume,
+	.driver		= {
+		.name	= DRIVER_NAME,
+	},
+};
+
+static int __init serial_omap_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&serial_omap_reg);
+	if (ret != 0)
+		return ret;
+	ret = platform_driver_register(&serial_omap_driver);
+	if (ret != 0)
+		uart_unregister_driver(&serial_omap_reg);
+	return ret;
+}
+
+static void __exit serial_omap_exit(void)
+{
+	platform_driver_unregister(&serial_omap_driver);
+	uart_unregister_driver(&serial_omap_reg);
+}
+
+module_init(serial_omap_init);
+module_exit(serial_omap_exit);
+
+MODULE_DESCRIPTION("OMAP High Speed UART driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Texas Instruments Inc");
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 563e2340091..295e89817de 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -196,6 +196,9 @@
 /* High Speed UART for Medfield */
 #define PORT_MFD	95
 
+/* TI OMAP-UART */
+#define PORT_OMAP	96
+
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>