[ARM PATCH] 1956/2: Re: Motorola i.MX serial driver

Patch from Sascha Hauer

Here is an updated version of the patch:

- updated the patch according to Russell's comments
- added proper sysrq handling
- update rx counter

Sascha Hauer

drivers/serial/Kconfig

@@ -386,6 +386,29 @@ config SERIAL_SA1100_CONSOLE
 	  your boot loader (lilo or loadlin) about how to pass options to the
 	  kernel at boot time.)
 
+config SERIAL_IMX
+	bool "IMX serial port support"
+	depends on ARM && ARCH_IMX
+	select SERIAL_CORE
+	help
+	  If you have a machine based on a Motorola IMX CPU you
+	  can enable its onboard serial port by enabling this option.
+
+config SERIAL_IMX_CONSOLE
+	bool "Console on IMX serial port"
+	depends on SERIAL_IMX
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you have enabled the serial port on the Motorola IMX
+	  CPU you can make it the console by answering Y to this option.
+
+	  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=ttySA0". (Try "man bootparam" or see the documentation of
+	  your boot loader (lilo or loadlin) about how to pass options to the
+	  kernel at boot time.)
+
 config SERIAL_SUNCORE
 	bool
 	depends on SPARC32 || SPARC64

drivers/serial/Makefile

@@ -41,5 +41,6 @@ obj-$(CONFIG_SERIAL_SH_SCI) += sh-sci.o
 obj-$(CONFIG_SERIAL_BAST_SIO) += bast_sio.o
 obj-$(CONFIG_SERIAL_SGI_L1_CONSOLE) += sn_console.o
 obj-$(CONFIG_SERIAL_CPM) += cpm_uart/
+obj-$(CONFIG_SERIAL_IMX) += imx.o
 obj-$(CONFIG_SERIAL_MPC52xx) += mpc52xx_uart.o
 obj-$(CONFIG_SERIAL_M32R_SIO) += m32r_sio.o

drivers/serial/imx.c

+/*
+ *  linux/drivers/serial/imx.c
+ *
+ *  Driver for Motorola IMX serial ports
+ *
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ *  Author: Sascha Hauer <sascha@saschahauer.de>
+ *  Copyright (C) 2004 Pengutronix
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/device.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/hardware.h>
+#include <asm/arch/serial.h>
+#include <asm/mach-types.h>
+
+#if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/serial_core.h>
+
+/* We've been assigned a range on the "Low-density serial ports" major */
+#define SERIAL_IMX_MAJOR	204
+#define MINOR_START		41
+
+#define NR_PORTS		2
+
+#define IMX_ISR_PASS_LIMIT	256
+
+/*
+ * This is the size of our serial port register set.
+ */
+#define UART_PORT_SIZE	0x100
+
+/*
+ * This determines how often we check the modem status signals
+ * for any change.  They generally aren't connected to an IRQ
+ * so we have to poll them.  We also check immediately before
+ * filling the TX fifo incase CTS has been dropped.
+ */
+#define MCTRL_TIMEOUT	(250*HZ/1000)
+
+#define DRIVER_NAME "IMX-uart"
+
+struct imx_port {
+	struct uart_port	port;
+	struct timer_list	timer;
+	unsigned int		old_status;
+	int txirq,rxirq;
+};
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void imx_mctrl_check(struct imx_port *sport)
+{
+	unsigned int status, changed;
+
+	status = sport->port.ops->get_mctrl(&sport->port);
+	changed = status ^ sport->old_status;
+
+	if (changed == 0)
+		return;
+
+	sport->old_status = status;
+
+	if (changed & TIOCM_RI)
+		sport->port.icount.rng++;
+	if (changed & TIOCM_DSR)
+		sport->port.icount.dsr++;
+	if (changed & TIOCM_CAR)
+		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
+	if (changed & TIOCM_CTS)
+		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
+
+	wake_up_interruptible(&sport->port.info->delta_msr_wait);
+}
+
+/*
+ * This is our per-port timeout handler, for checking the
+ * modem status signals.
+ */
+static void imx_timeout(unsigned long data)
+{
+	struct imx_port *sport = (struct imx_port *)data;
+	unsigned long flags;
+
+	if (sport->port.info) {
+		spin_lock_irqsave(&sport->port.lock, flags);
+		imx_mctrl_check(sport);
+		spin_unlock_irqrestore(&sport->port.lock, flags);
+
+		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
+	}
+}
+
+/*
+ * interrupts disabled on entry
+ */
+static void imx_stop_tx(struct uart_port *port, unsigned int tty_stop)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	UCR1((u32)sport->port.membase) &= ~UCR1_TXMPTYEN;
+}
+
+/*
+ * interrupts disabled on entry
+ */
+static void imx_stop_rx(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	UCR2((u32)sport->port.membase) &= ~UCR2_RXEN;
+}
+
+/*
+ * Set the modem control timer to fire immediately.
+ */
+static void imx_enable_ms(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	mod_timer(&sport->timer, jiffies);
+}
+
+static inline void imx_transmit_buffer(struct imx_port *sport)
+{
+	struct circ_buf *xmit = &sport->port.info->xmit;
+
+	do {
+		/* send xmit->buf[xmit->tail]
+		 * out the port here */
+		URTX0((u32)sport->port.membase) = xmit->buf[xmit->tail];
+		xmit->tail = (xmit->tail + 1) &
+		         (UART_XMIT_SIZE - 1);
+		sport->port.icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (!(UTS((u32)sport->port.membase) & UTS_TXFULL));
+
+	if (uart_circ_empty(xmit))
+		imx_stop_tx(&sport->port, 0);
+}
+
+/*
+ * interrupts disabled on entry
+ */
+static void imx_start_tx(struct uart_port *port, unsigned int tty_start)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	UCR1((u32)sport->port.membase) |= UCR1_TXMPTYEN;
+
+	if(UTS((u32)sport->port.membase) & UTS_TXEMPTY)
+		imx_transmit_buffer(sport);
+}
+
+static irqreturn_t imx_txint(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct imx_port *sport = (struct imx_port *)dev_id;
+	struct circ_buf *xmit = &sport->port.info->xmit;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock,flags);
+	if (sport->port.x_char)
+	{
+		/* Send next char */
+		URTX0((u32)sport->port.membase) = sport->port.x_char;
+		goto out;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
+		imx_stop_tx(&sport->port, 0);
+		goto out;
+	}
+
+	imx_transmit_buffer(sport);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&sport->port);
+
+out:
+	spin_unlock_irqrestore(&sport->port.lock,flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_rxint(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct imx_port *sport = dev_id;
+	unsigned int rx,flg,ignored = 0;
+	struct tty_struct *tty = sport->port.info->tty;
+	unsigned long flags;
+
+	rx = URXD0((u32)sport->port.membase);
+	spin_lock_irqsave(&sport->port.lock,flags);
+
+	do {
+		flg = TTY_NORMAL;
+		sport->port.icount.rx++;
+
+		if( USR2((u32)sport->port.membase) & USR2_BRCD ) {
+			USR2((u32)sport->port.membase) |= USR2_BRCD;
+			if(uart_handle_break(&sport->port))
+				goto ignore_char;
+		}
+
+		if (uart_handle_sysrq_char
+		            (&sport->port, (unsigned char)rx, regs))
+			goto ignore_char;
+
+		if( rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) )
+			goto handle_error;
+
+	error_return:
+		*tty->flip.flag_buf_ptr++ = flg;
+		*tty->flip.char_buf_ptr++ = (unsigned char)rx;
+		tty->flip.count++;
+
+		if (tty->flip.count >= TTY_FLIPBUF_SIZE)
+			goto out;
+
+	ignore_char:
+		rx = URXD0((u32)sport->port.membase);
+	} while(rx & URXD_CHARRDY);
+
+out:
+	spin_unlock_irqrestore(&sport->port.lock,flags);
+	tty_flip_buffer_push(tty);
+	return IRQ_HANDLED;
+
+handle_error:
+	if (rx & URXD_PRERR)
+		sport->port.icount.parity++;
+	else if (rx & URXD_FRMERR)
+		sport->port.icount.frame++;
+	if (rx & URXD_OVRRUN)
+		sport->port.icount.overrun++;
+
+	if (rx & sport->port.ignore_status_mask) {
+		if (++ignored > 100)
+			goto out;
+		goto ignore_char;
+	}
+
+	rx &= sport->port.read_status_mask;
+
+	if (rx & URXD_PRERR)
+		flg = TTY_PARITY;
+	else if (rx & URXD_FRMERR)
+		flg = TTY_FRAME;
+	if (rx & URXD_OVRRUN)
+		flg = TTY_OVERRUN;
+
+#ifdef SUPPORT_SYSRQ
+	sport->port.sysrq = 0;
+#endif
+	goto error_return;
+}
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int imx_tx_empty(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	return USR2((u32)sport->port.membase) & USR2_TXDC ?  TIOCSER_TEMT : 0;
+}
+
+static unsigned int imx_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+/*
+ * Interrupts always disabled.
+ */
+static void imx_break_ctl(struct uart_port *port, int break_state)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	if ( break_state != 0 )
+		UCR1((u32)sport->port.membase) |= UCR1_SNDBRK;
+	else
+		UCR1((u32)sport->port.membase) &= ~UCR1_SNDBRK;
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+#define TXTL 2 /* reset default */
+#define RXTL 1 /* reset default */
+
+static int imx_startup(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	int retval;
+	unsigned int val;
+	unsigned long flags;
+
+	/* set receiver / transmitter trigger level. We assume
+	 * that RFDIV has been set by the arch setup or by the bootloader.
+	 */
+	val = (UFCR((u32)sport->port.membase) & UFCR_RFDIV)  | TXTL<<10 | RXTL;
+	UFCR((u32)sport->port.membase) = val;
+
+	/* disable the DREN bit (Data Ready interrupt enable) before
+	 * requesting IRQs
+	 */
+	UCR4((u32)sport->port.membase) &= ~UCR4_DREN;
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(sport->rxirq, imx_rxint, 0,
+			     DRIVER_NAME, sport);
+	if (retval) goto error_out2;
+
+	retval = request_irq(sport->txirq, imx_txint, 0,
+			     "imx-uart", sport);
+	if (retval) goto error_out1;
+
+	/*
+	 * Finally, clear and enable interrupts
+	 */
+
+	UCR1((u32)sport->port.membase) |=
+	                 (UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_UARTEN);
+
+	UCR2((u32)sport->port.membase) |= (UCR2_RXEN | UCR2_TXEN);
+	/*
+	 * Enable modem status interrupts
+	 */
+	spin_lock_irqsave(&sport->port.lock,flags);
+	imx_enable_ms(&sport->port);
+	spin_unlock_irqrestore(&sport->port.lock,flags);
+
+	return 0;
+
+error_out1:
+	free_irq(sport->rxirq, sport);
+error_out2:
+	free_irq(sport->txirq, sport);
+	return retval;
+}
+
+static void imx_shutdown(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	/*
+	 * Stop our timer.
+	 */
+	del_timer_sync(&sport->timer);
+
+	/*
+	 * Free the interrupts
+	 */
+	free_irq(sport->txirq, sport);
+	free_irq(sport->rxirq, sport);
+
+	/*
+	 * Disable all interrupts, port and break condition.
+	 */
+
+	UCR1((u32)sport->port.membase) &=
+	                 ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_UARTEN);
+}
+
+static void
+imx_set_termios(struct uart_port *port, struct termios *termios,
+		   struct termios *old)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	unsigned long flags;
+	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
+	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+
+	/*
+	 * If we don't support modem control lines, don't allow
+	 * these to be set.
+	 */
+	if (0) {
+		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
+		termios->c_cflag |= CLOCAL;
+	}
+
+	/*
+	 * We only support CS7 and CS8.
+	 */
+	while ((termios->c_cflag & CSIZE) != CS7 &&
+	       (termios->c_cflag & CSIZE) != CS8) {
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= old_csize;
+		old_csize = CS8;
+	}
+
+	if ((termios->c_cflag & CSIZE) == CS8)
+		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
+	else
+		ucr2 = UCR2_SRST | UCR2_IRTS;
+
+	if (termios->c_cflag & CSTOPB)
+		ucr2 |= UCR2_STPB;
+	if (termios->c_cflag & PARENB) {
+		ucr2 |= UCR2_PREN;
+		if (!(termios->c_cflag & PARODD))
+			ucr2 |= UCR2_PROE;
+	}
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+	quot = uart_get_divisor(port, baud);
+
+	spin_lock_irqsave(&sport->port.lock, flags);
+
+	sport->port.read_status_mask = 0;
+	if (termios->c_iflag & INPCK)
+		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		sport->port.read_status_mask |= URXD_BRK;
+
+	/*
+	 * Characters to ignore
+	 */
+	sport->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		sport->port.ignore_status_mask |= URXD_PRERR;
+	if (termios->c_iflag & IGNBRK) {
+		sport->port.ignore_status_mask |= URXD_BRK;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			sport->port.ignore_status_mask |= URXD_OVRRUN;
+	}
+
+	del_timer_sync(&sport->timer);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * disable interrupts and drain transmitter
+	 */
+	old_ucr1 = UCR1((u32)sport->port.membase);
+	UCR1((u32)sport->port.membase) &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN);
+
+	while ( !(USR2((u32)sport->port.membase) & USR2_TXDC))
+		barrier();
+
+	/* then, disable everything */
+	old_txrxen = UCR2((u32)sport->port.membase) & ( UCR2_TXEN | UCR2_RXEN );
+	UCR2((u32)sport->port.membase) &= ~( UCR2_TXEN | UCR2_RXEN);
+
+	/* set the parity, stop bits and data size */
+	UCR2((u32)sport->port.membase) = ucr2;
+
+	/* set the baud rate. We assume uartclk = 16 MHz
+	 *
+	 * baud * 16   UBIR - 1
+	 * --------- = --------
+	 *  uartclk    UBMR - 1
+	 */
+	UBIR((u32)sport->port.membase) = (baud / 100) - 1;
+	UBMR((u32)sport->port.membase) = 10000 - 1;
+
+	UCR1((u32)sport->port.membase) = old_ucr1;
+	UCR2((u32)sport->port.membase) |= old_txrxen;
+
+	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
+		imx_enable_ms(&sport->port);
+
+	spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static const char *imx_type(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	return sport->port.type == PORT_IMX ? "IMX" : NULL;
+}
+
+/*
+ * Release the memory region(s) being used by 'port'.
+ */
+static void imx_release_port(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
+}
+
+/*
+ * Request the memory region(s) being used by 'port'.
+ */
+static int imx_request_port(struct uart_port *port)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
+			"imx-uart") != NULL ? 0 : -EBUSY;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void imx_config_port(struct uart_port *port, int flags)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+
+	if (flags & UART_CONFIG_TYPE &&
+	    imx_request_port(&sport->port) == 0)
+		sport->port.type = PORT_IMX;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ * The only change we allow are to the flags and type, and
+ * even then only between PORT_IMX and PORT_UNKNOWN
+ */
+static int
+imx_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	struct imx_port *sport = (struct imx_port *)port;
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
+		ret = -EINVAL;
+	if (sport->port.irq != ser->irq)
+		ret = -EINVAL;
+	if (ser->io_type != UPIO_MEM)
+		ret = -EINVAL;
+	if (sport->port.uartclk / 16 != ser->baud_base)
+		ret = -EINVAL;
+	if ((void *)sport->port.mapbase != ser->iomem_base)
+		ret = -EINVAL;
+	if (sport->port.iobase != ser->port)
+		ret = -EINVAL;
+	if (ser->hub6 != 0)
+		ret = -EINVAL;
+	return ret;
+}
+
+static struct uart_ops imx_pops = {
+	.tx_empty	= imx_tx_empty,
+	.set_mctrl	= imx_set_mctrl,
+	.get_mctrl	= imx_get_mctrl,
+	.stop_tx	= imx_stop_tx,
+	.start_tx	= imx_start_tx,
+	.stop_rx	= imx_stop_rx,
+	.enable_ms	= imx_enable_ms,
+	.break_ctl	= imx_break_ctl,
+	.startup	= imx_startup,
+	.shutdown	= imx_shutdown,
+	.set_termios	= imx_set_termios,
+	.type		= imx_type,
+	.release_port	= imx_release_port,
+	.request_port	= imx_request_port,
+	.config_port	= imx_config_port,
+	.verify_port	= imx_verify_port,
+};
+
+static struct imx_port imx_ports[] = {
+	{
+	.txirq  = UART1_MINT_TX,
+	.rxirq  = UART1_MINT_RX,
+	.port	= {
+		.type		= PORT_IMX,
+		.iotype		= SERIAL_IO_MEM,
+		.membase	= (void *)IMX_UART1_BASE,
+		.mapbase	= IMX_UART1_BASE, /* FIXME */
+		.irq		= UART1_MINT_RX,
+		.uartclk	= 16000000,
+		.fifosize	= 8,
+		.flags		= ASYNC_BOOT_AUTOCONF,
+		.ops		= &imx_pops,
+		.line		= 0,
+	},
+	}, {
+	.txirq  = UART2_MINT_TX,
+	.rxirq  = UART2_MINT_RX,
+	.port	= {
+		.type		= PORT_IMX,
+		.iotype		= SERIAL_IO_MEM,
+		.membase	= (void *)IMX_UART2_BASE,
+		.mapbase	= IMX_UART2_BASE, /* FIXME */
+		.irq		= UART2_MINT_RX,
+		.uartclk	= 16000000,
+		.fifosize	= 8,
+		.flags		= ASYNC_BOOT_AUTOCONF,
+		.ops		= &imx_pops,
+		.line		= 1,
+	},
+	}
+};
+
+/*
+ * Setup the IMX serial ports.
+ * Note also that we support "console=ttySMXx" where "x" is either 0 or 1.
+ * Which serial port this ends up being depends on the machine you're
+ * running this kernel on.  I'm not convinced that this is a good idea,
+ * but that's the way it traditionally works.
+ *
+ */
+static void __init imx_init_ports(void)
+{
+	static int first = 1;
+	int i;
+
+	if (!first)
+		return;
+	first = 0;
+
+	for (i = 0; i < ARRAY_SIZE(imx_ports); i++) {
+		init_timer(&imx_ports[i].timer);
+		imx_ports[i].timer.function = imx_timeout;
+		imx_ports[i].timer.data     = (unsigned long)&imx_ports[i];
+	}
+
+	imx_gpio_mode(PC9_PF_UART1_CTS);
+	imx_gpio_mode(PC10_PF_UART1_RTS);
+	imx_gpio_mode(PC11_PF_UART1_TXD);
+	imx_gpio_mode(PC12_PF_UART1_RXD);
+	imx_gpio_mode(PB28_PF_UART2_CTS);
+	imx_gpio_mode(PB29_PF_UART2_RTS);
+
+	imx_gpio_mode(PB30_PF_UART2_TXD);
+	imx_gpio_mode(PB31_PF_UART2_RXD);
+
+#if 0 /* We don't need these, on the mx1 the _modem_ side of the uart
+       * is implemented.
+       */
+	imx_gpio_mode(PD7_AF_UART2_DTR);
+	imx_gpio_mode(PD8_AF_UART2_DCD);
+	imx_gpio_mode(PD9_AF_UART2_RI);
+	imx_gpio_mode(PD10_AF_UART2_DSR);
+#endif
+
+
+}
+
+#ifdef CONFIG_SERIAL_IMX_CONSOLE
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+imx_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct imx_port *sport = &imx_ports[co->index];
+	unsigned int old_ucr1, old_ucr2, i;
+
+	/*
+	 *	First, save UCR1/2 and then disable interrupts
+	 */
+	old_ucr1 = UCR1((u32)sport->port.membase);
+	old_ucr2 = UCR2((u32)sport->port.membase);
+
+	UCR1((u32)sport->port.membase) =
+	                   (old_ucr1 | UCR1_UARTCLKEN | UCR1_UARTEN)
+	                   & ~(UCR1_TXMPTYEN | UCR1_RRDYEN);
+	UCR2((u32)sport->port.membase) = old_ucr2 | UCR2_TXEN;
+
+	/*
+	 *	Now, do each character
+	 */
+	for (i = 0; i < count; i++) {
+
+		while ((UTS((u32)sport->port.membase) & UTS_TXFULL))
+			barrier();
+
+		URTX0((u32)sport->port.membase) = s[i];
+
+		if (s[i] == '\n') {
+			while ((UTS((u32)sport->port.membase) & UTS_TXFULL))
+				barrier();
+			URTX0((u32)sport->port.membase) = '\r';
+		}
+	}
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore UCR1/2
+	 */
+	while (!(USR2((u32)sport->port.membase) & USR2_TXDC));
+
+	UCR1((u32)sport->port.membase) = old_ucr1;
+	UCR2((u32)sport->port.membase) = old_ucr2;
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+imx_console_get_options(struct imx_port *sport, int *baud,
+			   int *parity, int *bits)
+{
+	if ( UCR1((u32)sport->port.membase) | UCR1_UARTEN ) {
+		/* ok, the port was enabled */
+		unsigned int ucr2, ubir,ubmr, uartclk;
+
+		ucr2 = UCR2((u32)sport->port.membase);
+
+		*parity = 'n';
+		if (ucr2 & UCR2_PREN) {
+			if (ucr2 & UCR2_PROE)
+				*parity = 'o';
+			else
+				*parity = 'e';
+		}
+
+		if (ucr2 & UCR2_WS)
+			*bits = 8;
+		else
+			*bits = 7;
+
+		ubir = UBIR((u32)sport->port.membase) & 0xffff;
+		ubmr = UBMR((u32)sport->port.membase) & 0xffff;
+		uartclk = sport->port.uartclk;
+
+		*baud = ((uartclk/16) * (ubir + 1)) / (ubmr + 1);
+	}
+}
+
+static int __init
+imx_console_setup(struct console *co, char *options)
+{
+	struct imx_port *sport;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
+		co->index = 0;
+	sport = &imx_ports[co->index];
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		imx_console_get_options(sport, &baud, &parity, &bits);
+
+	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
+}
+
+extern struct uart_driver imx_reg;
+static struct console imx_console = {
+	.name		= "ttySMX",
+	.write		= imx_console_write,
+	.device		= uart_console_device,
+	.setup		= imx_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &imx_reg,
+};
+
+static int __init imx_rs_console_init(void)
+{
+	imx_init_ports();
+	register_console(&imx_console);
+	return 0;
+}
+console_initcall(imx_rs_console_init);
+
+#define IMX_CONSOLE	&imx_console
+#else
+#define IMX_CONSOLE	NULL
+#endif
+
+static struct uart_driver imx_reg = {
+	.owner          = THIS_MODULE,
+	.driver_name    = DRIVER_NAME,
+	.dev_name       = "ttySMX",
+	.devfs_name	= "ttsmx/",
+	.major          = SERIAL_IMX_MAJOR,
+	.minor          = MINOR_START,
+	.nr             = ARRAY_SIZE(imx_ports),
+	.cons           = IMX_CONSOLE,
+};
+
+static int serial_imx_suspend(struct device *_dev, u32 state, u32 level)
+{
+        struct imx_port *sport = dev_get_drvdata(_dev);
+
+        if (sport && level == SUSPEND_DISABLE)
+                uart_suspend_port(&imx_reg, &sport->port);
+
+        return 0;
+}
+
+static int serial_imx_resume(struct device *_dev, u32 level)
+{
+        struct imx_port *sport = dev_get_drvdata(_dev);
+
+        if (sport && level == RESUME_ENABLE)
+                uart_resume_port(&imx_reg, &sport->port);
+
+        return 0;
+}
+
+static int serial_imx_probe(struct device *_dev)
+{
+	struct platform_device *dev = to_platform_device(_dev);
+
+	imx_ports[dev->id].port.dev = _dev;
+	uart_add_one_port(&imx_reg, &imx_ports[dev->id].port);
+	dev_set_drvdata(_dev, &imx_ports[dev->id]);
+	return 0;
+}
+
+static int serial_imx_remove(struct device *_dev)
+{
+	struct imx_port *sport = dev_get_drvdata(_dev);
+
+	dev_set_drvdata(_dev, NULL);
+
+	if (sport)
+		uart_remove_one_port(&imx_reg, &sport->port);
+
+	return 0;
+}
+
+static struct device_driver serial_imx_driver = {
+        .name           = "imx-uart",
+        .bus            = &platform_bus_type,
+        .probe          = serial_imx_probe,
+        .remove         = serial_imx_remove,
+
+	.suspend	= serial_imx_suspend,
+	.resume		= serial_imx_resume,
+};
+
+static int __init imx_serial_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Serial: IMX driver\n");
+
+	imx_init_ports();
+
+	ret = uart_register_driver(&imx_reg);
+	if (ret)
+		return ret;
+
+	ret = driver_register(&serial_imx_driver);
+	if (ret != 0)
+		uart_unregister_driver(&imx_reg);
+
+	return 0;
+}
+
+static void __exit imx_serial_exit(void)
+{
+	uart_unregister_driver(&imx_reg);
+}
+
+module_init(imx_serial_init);
+module_exit(imx_serial_exit);
+
+MODULE_AUTHOR("Sascha Hauer");
+MODULE_DESCRIPTION("IMX generic serial port driver");
+MODULE_LICENSE("GPL");