serial: Add auart driver for i.MX23/28

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 815 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index c1df7676a73d..b7a4d81e643d 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1595,4 +1595,19 @@ config SERIAL_PCH_UART
           This driver is for PCH(Platform controller Hub) UART of Intel EG20T
           which is an IOH(Input/Output Hub) for x86 embedded processor.
           Enabling PCH_DMA, this PCH UART works as DMA mode.
+
+config SERIAL_MXS_AUART
+        depends on ARCH_MXS
+        tristate "MXS AUART support"
+        select SERIAL_CORE
+        help
+          This driver supports the MXS Application UART (AUART) port.
+
+config SERIAL_MXS_AUART_CONSOLE
+        bool "MXS AUART console support"
+        depends on SERIAL_MXS_AUART=y
+        select SERIAL_CORE_CONSOLE
+        help
+          Enable a MXS AUART port to be the system console.
+
 endmenu
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 8ea92e9c73b0..c8550719de5a 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -92,3 +92,4 @@ obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)    += mfd.o
 obj-$(CONFIG_SERIAL_IFX6X60)    += ifx6x60.o
 obj-$(CONFIG_SERIAL_PCH_UART)   += pch_uart.o
+obj-$(CONFIG_SERIAL_MXS_AUART) += mxs-auart.o
diff --git a/drivers/serial/mxs-auart.c b/drivers/serial/mxs-auart.c
new file mode 100644
index 000000000000..6d01ac968103
--- /dev/null
+++ b/drivers/serial/mxs-auart.c
@@ -0,0 +1,799 @@
+/*
+ * Freescale STMP37XX/STMP378X Application UART driver
+ *
+ * Author: dmitry pervushin <dimka@embeddedalley.com>
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/tty_flip.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#include <asm/cacheflush.h>
+
+#define MXS_AUART_PORTS 5
+
+#define AUART_CTRL0                     0x00000000
+#define AUART_CTRL0_SET                 0x00000004
+#define AUART_CTRL0_CLR                 0x00000008
+#define AUART_CTRL0_TOG                 0x0000000c
+#define AUART_CTRL1                     0x00000010
+#define AUART_CTRL1_SET                 0x00000014
+#define AUART_CTRL1_CLR                 0x00000018
+#define AUART_CTRL1_TOG                 0x0000001c
+#define AUART_CTRL2                     0x00000020
+#define AUART_CTRL2_SET                 0x00000024
+#define AUART_CTRL2_CLR                 0x00000028
+#define AUART_CTRL2_TOG                 0x0000002c
+#define AUART_LINECTRL                  0x00000030
+#define AUART_LINECTRL_SET              0x00000034
+#define AUART_LINECTRL_CLR              0x00000038
+#define AUART_LINECTRL_TOG              0x0000003c
+#define AUART_LINECTRL2                 0x00000040
+#define AUART_LINECTRL2_SET             0x00000044
+#define AUART_LINECTRL2_CLR             0x00000048
+#define AUART_LINECTRL2_TOG             0x0000004c
+#define AUART_INTR                      0x00000050
+#define AUART_INTR_SET                  0x00000054
+#define AUART_INTR_CLR                  0x00000058
+#define AUART_INTR_TOG                  0x0000005c
+#define AUART_DATA                      0x00000060
+#define AUART_STAT                      0x00000070
+#define AUART_DEBUG                     0x00000080
+#define AUART_VERSION                   0x00000090
+#define AUART_AUTOBAUD                  0x000000a0
+
+#define AUART_CTRL0_SFTRST                      (1 << 31)
+#define AUART_CTRL0_CLKGATE                     (1 << 30)
+
+#define AUART_CTRL2_CTSEN                       (1 << 15)
+#define AUART_CTRL2_RTS                         (1 << 11)
+#define AUART_CTRL2_RXE                         (1 << 9)
+#define AUART_CTRL2_TXE                         (1 << 8)
+#define AUART_CTRL2_UARTEN                      (1 << 0)
+
+#define AUART_LINECTRL_BAUD_DIVINT_SHIFT        16
+#define AUART_LINECTRL_BAUD_DIVINT_MASK         0xffff0000
+#define AUART_LINECTRL_BAUD_DIVINT(v)           (((v) & 0xffff) << 16)
+#define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT       8
+#define AUART_LINECTRL_BAUD_DIVFRAC_MASK        0x00003f00
+#define AUART_LINECTRL_BAUD_DIVFRAC(v)          (((v) & 0x3f) << 8)
+#define AUART_LINECTRL_WLEN_MASK                0x00000060
+#define AUART_LINECTRL_WLEN(v)                  (((v) & 0x3) << 5)
+#define AUART_LINECTRL_FEN                      (1 << 4)
+#define AUART_LINECTRL_STP2                     (1 << 3)
+#define AUART_LINECTRL_EPS                      (1 << 2)
+#define AUART_LINECTRL_PEN                      (1 << 1)
+#define AUART_LINECTRL_BRK                      (1 << 0)
+
+#define AUART_INTR_RTIEN                        (1 << 22)
+#define AUART_INTR_TXIEN                        (1 << 21)
+#define AUART_INTR_RXIEN                        (1 << 20)
+#define AUART_INTR_CTSMIEN                      (1 << 17)
+#define AUART_INTR_RTIS                         (1 << 6)
+#define AUART_INTR_TXIS                         (1 << 5)
+#define AUART_INTR_RXIS                         (1 << 4)
+#define AUART_INTR_CTSMIS                       (1 << 1)
+
+#define AUART_STAT_BUSY                         (1 << 29)
+#define AUART_STAT_CTS                          (1 << 28)
+#define AUART_STAT_TXFE                         (1 << 27)
+#define AUART_STAT_TXFF                         (1 << 25)
+#define AUART_STAT_RXFE                         (1 << 24)
+#define AUART_STAT_OERR                         (1 << 19)
+#define AUART_STAT_BERR                         (1 << 18)
+#define AUART_STAT_PERR                         (1 << 17)
+#define AUART_STAT_FERR                         (1 << 16)
+
+static struct uart_driver auart_driver;
+
+struct mxs_auart_port {
+        struct uart_port port;
+
+        unsigned int flags;
+        unsigned int ctrl;
+
+        unsigned int irq;
+
+        struct clk *clk;
+        struct device *dev;
+};
+
+static void mxs_auart_stop_tx(struct uart_port *u);
+
+#define to_auart_port(u) container_of(u, struct mxs_auart_port, port)
+
+static inline void mxs_auart_tx_chars(struct mxs_auart_port *s)
+{
+        struct circ_buf *xmit = &s->port.state->xmit;
+
+        while (!(readl(s->port.membase + AUART_STAT) &
+                 AUART_STAT_TXFF)) {
+                if (s->port.x_char) {
+                        s->port.icount.tx++;
+                        writel(s->port.x_char,
+                                     s->port.membase + AUART_DATA);
+                        s->port.x_char = 0;
+                        continue;
+                }
+                if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) {
+                        s->port.icount.tx++;
+                        writel(xmit->buf[xmit->tail],
+                                     s->port.membase + AUART_DATA);
+                        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+                        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+                                uart_write_wakeup(&s->port);
+                } else
+                        break;
+        }
+        if (uart_circ_empty(&(s->port.state->xmit)))
+                writel(AUART_INTR_TXIEN,
+                             s->port.membase + AUART_INTR_CLR);
+        else
+                writel(AUART_INTR_TXIEN,
+                             s->port.membase + AUART_INTR_SET);
+
+        if (uart_tx_stopped(&s->port))
+                mxs_auart_stop_tx(&s->port);
+}
+
+static void mxs_auart_rx_char(struct mxs_auart_port *s)
+{
+        int flag;
+        u32 stat;
+        u8 c;
+
+        c = readl(s->port.membase + AUART_DATA);
+        stat = readl(s->port.membase + AUART_STAT);
+
+        flag = TTY_NORMAL;
+        s->port.icount.rx++;
+
+        if (stat & AUART_STAT_BERR) {
+                s->port.icount.brk++;
+                if (uart_handle_break(&s->port))
+                        goto out;
+        } else if (stat & AUART_STAT_PERR) {
+                s->port.icount.parity++;
+        } else if (stat & AUART_STAT_FERR) {
+                s->port.icount.frame++;
+        }
+
+        /*
+         * Mask off conditions which should be ingored.
+         */
+        stat &= s->port.read_status_mask;
+
+        if (stat & AUART_STAT_BERR) {
+                flag = TTY_BREAK;
+        } else if (stat & AUART_STAT_PERR)
+                flag = TTY_PARITY;
+        else if (stat & AUART_STAT_FERR)
+                flag = TTY_FRAME;
+
+        if (stat & AUART_STAT_OERR)
+                s->port.icount.overrun++;
+
+        if (uart_handle_sysrq_char(&s->port, c))
+                goto out;
+
+        uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag);
+out:
+        writel(stat, s->port.membase + AUART_STAT);
+}
+
+static void mxs_auart_rx_chars(struct mxs_auart_port *s)
+{
+        struct tty_struct *tty = s->port.state->port.tty;
+        u32 stat = 0;
+
+        for (;;) {
+                stat = readl(s->port.membase + AUART_STAT);
+                if (stat & AUART_STAT_RXFE)
+                        break;
+                mxs_auart_rx_char(s);
+        }
+
+        writel(stat, s->port.membase + AUART_STAT);
+        tty_flip_buffer_push(tty);
+}
+
+static int mxs_auart_request_port(struct uart_port *u)
+{
+        return 0;
+}
+
+static int mxs_auart_verify_port(struct uart_port *u,
+                                    struct serial_struct *ser)
+{
+        if (u->type != PORT_UNKNOWN && u->type != PORT_IMX)
+                return -EINVAL;
+        return 0;
+}
+
+static void mxs_auart_config_port(struct uart_port *u, int flags)
+{
+}
+
+static const char *mxs_auart_type(struct uart_port *u)
+{
+        struct mxs_auart_port *s = to_auart_port(u);
+
+        return dev_name(s->dev);
+}
+
+static void mxs_auart_release_port(struct uart_port *u)
+{
+}
+
+static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
+{
+        struct mxs_auart_port *s = to_auart_port(u);
+
+        u32 ctrl = readl(u->membase + AUART_CTRL2);
+
+        ctrl &= ~AUART_CTRL2_RTS;
+        if (mctrl & TIOCM_RTS)
+                ctrl |= AUART_CTRL2_RTS;
+        s->ctrl = mctrl;
+        writel(ctrl, u->membase + AUART_CTRL2);
+}
+
+static u32 mxs_auart_get_mctrl(struct uart_port *u)
+{
+        struct mxs_auart_port *s = to_auart_port(u);
+        u32 stat = readl(u->membase + AUART_STAT);
+        int ctrl2 = readl(u->membase + AUART_CTRL2);
+        u32 mctrl = s->ctrl;
+
+        mctrl &= ~TIOCM_CTS;
+        if (stat & AUART_STAT_CTS)
+                mctrl |= TIOCM_CTS;
+
+        if (ctrl2 & AUART_CTRL2_RTS)
+                mctrl |= TIOCM_RTS;
+
+        return mctrl;
+}
+
+static void mxs_auart_settermios(struct uart_port *u,
+                                 struct ktermios *termios,
+                                 struct ktermios *old)
+{
+        u32 bm, ctrl, ctrl2, div;
+        unsigned int cflag, baud;
+
+        cflag = termios->c_cflag;
+
+        ctrl = AUART_LINECTRL_FEN;
+        ctrl2 = readl(u->membase + AUART_CTRL2);
+
+        /* byte size */
+        switch (cflag & CSIZE) {
+        case CS5:
+                bm = 0;
+                break;
+        case CS6:
+                bm = 1;
+                break;
+        case CS7:
+                bm = 2;
+                break;
+        case CS8:
+                bm = 3;
+                break;
+        default:
+                return;
+        }
+
+        ctrl |= AUART_LINECTRL_WLEN(bm);
+
+        /* parity */
+        if (cflag & PARENB) {
+                ctrl |= AUART_LINECTRL_PEN;
+                if ((cflag & PARODD) == 0)
+                        ctrl |= AUART_LINECTRL_EPS;
+        }
+
+        u->read_status_mask = 0;
+
+        if (termios->c_iflag & INPCK)
+                u->read_status_mask |= AUART_STAT_PERR;
+        if (termios->c_iflag & (BRKINT | PARMRK))
+                u->read_status_mask |= AUART_STAT_BERR;
+
+        /*
+         * Characters to ignore
+         */
+        u->ignore_status_mask = 0;
+        if (termios->c_iflag & IGNPAR)
+                u->ignore_status_mask |= AUART_STAT_PERR;
+        if (termios->c_iflag & IGNBRK) {
+                u->ignore_status_mask |= AUART_STAT_BERR;
+                /*
+                 * If we're ignoring parity and break indicators,
+                 * ignore overruns too (for real raw support).
+                 */
+                if (termios->c_iflag & IGNPAR)
+                        u->ignore_status_mask |= AUART_STAT_OERR;
+        }
+
+        /*
+         * ignore all characters if CREAD is not set
+         */
+        if (cflag & CREAD)
+                ctrl2 |= AUART_CTRL2_RXE;
+        else
+                ctrl2 &= ~AUART_CTRL2_RXE;
+
+        /* figure out the stop bits requested */
+        if (cflag & CSTOPB)
+                ctrl |= AUART_LINECTRL_STP2;
+
+        /* figure out the hardware flow control settings */
+        if (cflag & CRTSCTS)
+                ctrl2 |= AUART_CTRL2_CTSEN;
+        else
+                ctrl2 &= ~AUART_CTRL2_CTSEN;
+
+        /* set baud rate */
+        baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk);
+        div = u->uartclk * 32 / baud;
+        ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F);
+        ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6);
+
+        writel(ctrl, u->membase + AUART_LINECTRL);
+        writel(ctrl2, u->membase + AUART_CTRL2);
+}
+
+static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
+{
+        u32 istatus, istat;
+        struct mxs_auart_port *s = context;
+        u32 stat = readl(s->port.membase + AUART_STAT);
+
+        istatus = istat = readl(s->port.membase + AUART_INTR);
+
+        if (istat & AUART_INTR_CTSMIS) {
+                uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS);
+                writel(AUART_INTR_CTSMIS,
+                                s->port.membase + AUART_INTR_CLR);
+                istat &= ~AUART_INTR_CTSMIS;
+        }
+
+        if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) {
+                mxs_auart_rx_chars(s);
+                istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS);
+        }
+
+        if (istat & AUART_INTR_TXIS) {
+                mxs_auart_tx_chars(s);
+                istat &= ~AUART_INTR_TXIS;
+        }
+
+        writel(istatus & (AUART_INTR_RTIS
+                | AUART_INTR_TXIS
+                | AUART_INTR_RXIS
+                | AUART_INTR_CTSMIS),
+                        s->port.membase + AUART_INTR_CLR);
+
+        return IRQ_HANDLED;
+}
+
+static void mxs_auart_reset(struct uart_port *u)
+{
+        int i;
+        unsigned int reg;
+
+        writel(AUART_CTRL0_SFTRST, u->membase + AUART_CTRL0_CLR);
+
+        for (i = 0; i < 10000; i++) {
+                reg = readl(u->membase + AUART_CTRL0);
+                if (!(reg & AUART_CTRL0_SFTRST))
+                        break;
+                udelay(3);
+        }
+        writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
+}
+
+static int mxs_auart_startup(struct uart_port *u)
+{
+        struct mxs_auart_port *s = to_auart_port(u);
+
+        clk_enable(s->clk);
+
+        writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR);
+
+        writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_SET);
+
+        writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
+                        u->membase + AUART_INTR);
+
+        /*
+         * Enable fifo so all four bytes of a DMA word are written to
+         * output (otherwise, only the LSB is written, ie. 1 in 4 bytes)
+         */
+        writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET);
+
+        return 0;
+}
+
+static void mxs_auart_shutdown(struct uart_port *u)
+{
+        struct mxs_auart_port *s = to_auart_port(u);
+
+        writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR);
+
+        writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET);
+
+        writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
+                        u->membase + AUART_INTR_CLR);
+
+        clk_disable(s->clk);
+}
+
+static unsigned int mxs_auart_tx_empty(struct uart_port *u)
+{
+        if (readl(u->membase + AUART_STAT) & AUART_STAT_TXFE)
+                return TIOCSER_TEMT;
+        else
+                return 0;
+}
+
+static void mxs_auart_start_tx(struct uart_port *u)
+{
+        struct mxs_auart_port *s = to_auart_port(u);
+
+        /* enable transmitter */
+        writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_SET);
+
+        mxs_auart_tx_chars(s);
+}
+
+static void mxs_auart_stop_tx(struct uart_port *u)
+{
+        writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_CLR);
+}
+
+static void mxs_auart_stop_rx(struct uart_port *u)
+{
+        writel(AUART_CTRL2_RXE, u->membase + AUART_CTRL2_CLR);
+}
+
+static void mxs_auart_break_ctl(struct uart_port *u, int ctl)
+{
+        if (ctl)
+                writel(AUART_LINECTRL_BRK,
+                             u->membase + AUART_LINECTRL_SET);
+        else
+                writel(AUART_LINECTRL_BRK,
+                             u->membase + AUART_LINECTRL_CLR);
+}
+
+static void mxs_auart_enable_ms(struct uart_port *port)
+{
+        /* just empty */
+}
+
+static struct uart_ops mxs_auart_ops = {
+        .tx_empty       = mxs_auart_tx_empty,
+        .start_tx       = mxs_auart_start_tx,
+        .stop_tx        = mxs_auart_stop_tx,
+        .stop_rx        = mxs_auart_stop_rx,
+        .enable_ms      = mxs_auart_enable_ms,
+        .break_ctl      = mxs_auart_break_ctl,
+        .set_mctrl      = mxs_auart_set_mctrl,
+        .get_mctrl      = mxs_auart_get_mctrl,
+        .startup        = mxs_auart_startup,
+        .shutdown       = mxs_auart_shutdown,
+        .set_termios    = mxs_auart_settermios,
+        .type           = mxs_auart_type,
+        .release_port   = mxs_auart_release_port,
+        .request_port   = mxs_auart_request_port,
+        .config_port    = mxs_auart_config_port,
+        .verify_port    = mxs_auart_verify_port,
+};
+
+static struct mxs_auart_port *auart_port[MXS_AUART_PORTS];
+
+#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
+static void mxs_auart_console_putchar(struct uart_port *port, int ch)
+{
+        unsigned int to = 1000;
+
+        while (readl(port->membase + AUART_STAT) & AUART_STAT_TXFF) {
+                if (!to--)
+                        break;
+                udelay(1);
+        }
+
+        writel(ch, port->membase + AUART_DATA);
+}
+
+static void
+auart_console_write(struct console *co, const char *str, unsigned int count)
+{
+        struct mxs_auart_port *s;
+        struct uart_port *port;
+        unsigned int old_ctrl0, old_ctrl2;
+        unsigned int to = 1000;
+
+        if (co->index > MXS_AUART_PORTS || co->index < 0)
+                return;
+
+        s = auart_port[co->index];
+        port = &s->port;
+
+        clk_enable(s->clk);
+
+        /* First save the CR then disable the interrupts */
+        old_ctrl2 = readl(port->membase + AUART_CTRL2);
+        old_ctrl0 = readl(port->membase + AUART_CTRL0);
+
+        writel(AUART_CTRL0_CLKGATE,
+                     port->membase + AUART_CTRL0_CLR);
+        writel(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE,
+                     port->membase + AUART_CTRL2_SET);
+
+        uart_console_write(port, str, count, mxs_auart_console_putchar);
+
+        /*
+         * Finally, wait for transmitter to become empty
+         * and restore the TCR
+         */
+        while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) {
+                if (!to--)
+                        break;
+                udelay(1);
+        }
+
+        writel(old_ctrl0, port->membase + AUART_CTRL0);
+        writel(old_ctrl2, port->membase + AUART_CTRL2);
+
+        clk_disable(s->clk);
+}
+
+static void __init
+auart_console_get_options(struct uart_port *port, int *baud,
+                          int *parity, int *bits)
+{
+        unsigned int lcr_h, quot;
+
+        if (!(readl(port->membase + AUART_CTRL2) & AUART_CTRL2_UARTEN))
+                return;
+
+        lcr_h = readl(port->membase + AUART_LINECTRL);
+
+        *parity = 'n';
+        if (lcr_h & AUART_LINECTRL_PEN) {
+                if (lcr_h & AUART_LINECTRL_EPS)
+                        *parity = 'e';
+                else
+                        *parity = 'o';
+        }
+
+        if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2))
+                *bits = 7;
+        else
+                *bits = 8;
+
+        quot = ((readl(port->membase + AUART_LINECTRL)
+                        & AUART_LINECTRL_BAUD_DIVINT_MASK))
+                            >> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6);
+        quot |= ((readl(port->membase + AUART_LINECTRL)
+                        & AUART_LINECTRL_BAUD_DIVFRAC_MASK))
+                                >> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT;
+        if (quot == 0)
+                quot = 1;
+
+        *baud = (port->uartclk << 2) / quot;
+}
+
+static int __init
+auart_console_setup(struct console *co, char *options)
+{
+        struct mxs_auart_port *s;
+        int baud = 9600;
+        int bits = 8;
+        int parity = 'n';
+        int flow = 'n';
+        int ret;
+
+        /*
+         * 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(auart_port))
+                co->index = 0;
+        s = auart_port[co->index];
+        if (!s)
+                return -ENODEV;
+
+        clk_enable(s->clk);
+
+        if (options)
+                uart_parse_options(options, &baud, &parity, &bits, &flow);
+        else
+                auart_console_get_options(&s->port, &baud, &parity, &bits);
+
+        ret = uart_set_options(&s->port, co, baud, parity, bits, flow);
+
+        clk_disable(s->clk);
+
+        return ret;
+}
+
+static struct console auart_console = {
+        .name           = "ttyAPP",
+        .write          = auart_console_write,
+        .device         = uart_console_device,
+        .setup          = auart_console_setup,
+        .flags          = CON_PRINTBUFFER,
+        .index          = -1,
+        .data           = &auart_driver,
+};
+#endif
+
+static struct uart_driver auart_driver = {
+        .owner          = THIS_MODULE,
+        .driver_name    = "ttyAPP",
+        .dev_name       = "ttyAPP",
+        .major          = 0,
+        .minor          = 0,
+        .nr             = MXS_AUART_PORTS,
+#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE
+        .cons =         &auart_console,
+#endif
+};
+
+static int __devinit mxs_auart_probe(struct platform_device *pdev)
+{
+        struct mxs_auart_port *s;
+        u32 version;
+        int ret = 0;
+        struct resource *r;
+
+        s = kzalloc(sizeof(struct mxs_auart_port), GFP_KERNEL);
+        if (!s) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        s->clk = clk_get(&pdev->dev, NULL);
+        if (IS_ERR(s->clk)) {
+                ret = PTR_ERR(s->clk);
+                goto out_free;
+        }
+
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!r) {
+                ret = -ENXIO;
+                goto out_free_clk;
+        }
+
+        s->port.mapbase = r->start;
+        s->port.membase = ioremap(r->start, resource_size(r));
+        s->port.ops = &mxs_auart_ops;
+        s->port.iotype = UPIO_MEM;
+        s->port.line = pdev->id < 0 ? 0 : pdev->id;
+        s->port.fifosize = 16;
+        s->port.uartclk = clk_get_rate(s->clk);
+        s->port.type = PORT_IMX;
+        s->port.dev = s->dev = get_device(&pdev->dev);
+
+        s->flags = 0;
+        s->ctrl = 0;
+
+        s->irq = platform_get_irq(pdev, 0);
+        s->port.irq = s->irq;
+        ret = request_irq(s->irq, mxs_auart_irq_handle, 0, dev_name(&pdev->dev), s);
+        if (ret)
+                goto out_free_clk;
+
+        platform_set_drvdata(pdev, s);
+
+        auart_port[pdev->id] = s;
+
+        mxs_auart_reset(&s->port);
+
+        ret = uart_add_one_port(&auart_driver, &s->port);
+        if (ret)
+                goto out_free_irq;
+
+        version = readl(s->port.membase + AUART_VERSION);
+        dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n",
+               (version >> 24) & 0xff,
+               (version >> 16) & 0xff, version & 0xffff);
+
+        return 0;
+
+out_free_irq:
+        auart_port[pdev->id] = NULL;
+        free_irq(s->irq, s);
+out_free_clk:
+        clk_put(s->clk);
+out_free:
+        kfree(s);
+out:
+        return ret;
+}
+
+static int __devexit mxs_auart_remove(struct platform_device *pdev)
+{
+        struct mxs_auart_port *s = platform_get_drvdata(pdev);
+
+        uart_remove_one_port(&auart_driver, &s->port);
+
+        auart_port[pdev->id] = NULL;
+
+        clk_put(s->clk);
+        free_irq(s->irq, s);
+        kfree(s);
+
+        return 0;
+}
+
+static struct platform_driver mxs_auart_driver = {
+        .probe = mxs_auart_probe,
+        .remove = __devexit_p(mxs_auart_remove),
+        .driver = {
+                .name = "mxs-auart",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init mxs_auart_init(void)
+{
+        int r;
+
+        r = uart_register_driver(&auart_driver);
+        if (r)
+                goto out;
+
+        r = platform_driver_register(&mxs_auart_driver);
+        if (r)
+                goto out_err;
+
+        return 0;
+out_err:
+        uart_unregister_driver(&auart_driver);
+out:
+        return r;
+}
+
+static void __exit mxs_auart_exit(void)
+{
+        platform_driver_unregister(&mxs_auart_driver);
+        uart_unregister_driver(&auart_driver);
+}
+
+module_init(mxs_auart_init);
+module_exit(mxs_auart_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Freescale MXS application uart driver");