Patchwork [v2] serial: Add OMAP high-speed UART driver

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Submitter Govindraj.R
Date May 24, 2010, 1:43 p.m.
Message ID <58269.192.168.10.88.1274708590.squirrel@dbdmail.itg.ti.com>
Download mbox | patch
Permalink /patch/101874/
State New, archived
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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 0000000..0d6f076
--- /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 f55c494..4346bfa 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1387,6 +1387,33 @@  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_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 6aa4723..87e4d7a 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -83,3 +83,4 @@  obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
 obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.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 0000000..b40a911
--- /dev/null
+++ b/drivers/serial/omap-serial.c
@@ -0,0 +1,1318 @@ 
+/*
+ * 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 <asm/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;
+	}
+
+	xmit = &up->port.state->xmit;
+	if (uart_circ_empty(xmit) || up->uart_dma.tx_dma_used)
+		return;
+
+	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;
+	}
+
+	start = up->uart_dma.tx_buf_dma_phys +
+				(xmit->tail & (UART_XMIT_SIZE - 1));
+	spin_lock(&(up->uart_dma.tx_lock));
+	up->uart_dma.tx_dma_used = true;
+	spin_unlock(&(up->uart_dma.tx_lock));
+
+	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)
+{
+	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_IER_RLSI) {
+		if (!up->use_dma) {
+			if (lsr & UART_LSR_DR)
+				receive_chars(up, &lsr);
+		} else {
+			up->ier &= ~UART_IER_RDI;
+			serial_out(up, UART_IER, up->ier);
+			if (serial_omap_start_rxdma(up) != 0)
+				if (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) {
+		int tmp;
+		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;
+		tmp = serial_in(up, UART_OMAP_SYSC) & OMAP_UART_SYSC_RESET;
+		serial_out(up, UART_OMAP_SYSC, tmp); /* force-idle */
+	}
+	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, 0);
+	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 int ier;
+
+	/*
+	 * 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);
+}
+
+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';
+	int r;
+
+	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);
+
+	r = uart_set_options(&up->port, co, baud, parity, bits, flow);
+
+	return r;
+}
+
+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
+
+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;
+			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;
+			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;
+	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(pdev, IORESOURCE_DMA, 0);
+	if (!dma_rx) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	dma_tx = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+	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 = 1;
+		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,
+	},
+};
+
+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;
+}
+
+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 78dd1e7..caaa311 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -182,6 +182,9 @@ 
 /* Aeroflex Gaisler GRLIB APBUART */
 #define PORT_APBUART    90

+/* TI OMAP-UART */
+#define PORT_OMAP	91
+
 #ifdef __KERNEL__

 #include <linux/compiler.h>