serial: Add auart driver for i.MX23/28
authorSascha Hauer <s.hauer@pengutronix.de>
Tue, 11 Jan 2011 14:54:54 +0000 (15:54 +0100)
committerSascha Hauer <s.hauer@pengutronix.de>
Tue, 25 Jan 2011 07:37:20 +0000 (08:37 +0100)
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
drivers/serial/Kconfig
drivers/serial/Makefile
drivers/serial/mxs-auart.c [new file with mode: 0644]

index c1df7676a73d6f04cf6357e2d01a044556164fca..b7a4d81e643dda266753a05b126c0207ce144105 100644 (file)
@@ -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
index 8ea92e9c73b046cb66cb43ee3d6daa9ddd3049ab..c8550719de5ac26f27635241e1046a6ae84fbb98 100644 (file)
@@ -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 (file)
index 0000000..6d01ac9
--- /dev/null
@@ -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");