sa1100.c

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/*
 *  Driver for SA11x0 serial ports
 *
 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 *
 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
 *
 * 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
 */

#if defined(CONFIG_SERIAL_SA1100_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/io.h>

#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
#include <asm/mach/serial_sa1100.h>

/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_SA1100_MAJOR 204
#define MINOR_START     5

#define NR_PORTS        3

#define SA1100_ISR_PASS_LIMIT   256

/*
 * Convert from ignore_status_mask or read_status_mask to UTSR[01]
 */
#define SM_TO_UTSR0(x)  ((x) & 0xff)
#define SM_TO_UTSR1(x)  ((x) >> 8)
#define UTSR0_TO_SM(x)  ((x))
#define UTSR1_TO_SM(x)  ((x) << 8)

#define UART_GET_UTCR0(sport)   __raw_readl((sport)->port.membase + UTCR0)
#define UART_GET_UTCR1(sport)   __raw_readl((sport)->port.membase + UTCR1)
#define UART_GET_UTCR2(sport)   __raw_readl((sport)->port.membase + UTCR2)
#define UART_GET_UTCR3(sport)   __raw_readl((sport)->port.membase + UTCR3)
#define UART_GET_UTSR0(sport)   __raw_readl((sport)->port.membase + UTSR0)
#define UART_GET_UTSR1(sport)   __raw_readl((sport)->port.membase + UTSR1)
#define UART_GET_CHAR(sport)    __raw_readl((sport)->port.membase + UTDR)

#define UART_PUT_UTCR0(sport,v) __raw_writel((v),(sport)->port.membase + UTCR0)
#define UART_PUT_UTCR1(sport,v) __raw_writel((v),(sport)->port.membase + UTCR1)
#define UART_PUT_UTCR2(sport,v) __raw_writel((v),(sport)->port.membase + UTCR2)
#define UART_PUT_UTCR3(sport,v) __raw_writel((v),(sport)->port.membase + UTCR3)
#define UART_PUT_UTSR0(sport,v) __raw_writel((v),(sport)->port.membase + UTSR0)
#define UART_PUT_UTSR1(sport,v) __raw_writel((v),(sport)->port.membase + UTSR1)
#define UART_PUT_CHAR(sport,v)  __raw_writel((v),(sport)->port.membase + UTDR)

/*
 * This is the size of our serial port register set.
 */
#define UART_PORT_SIZE  0x24

/*
 * 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)

struct sa1100_port {
    struct uart_port    port;
    struct timer_list   timer;
    unsigned int        old_status;
};

/*
 * Handle any change of modem status signal since we were last called.
 */
static void sa1100_mctrl_check(struct sa1100_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.state->port.delta_msr_wait);
}

/*
 * This is our per-port timeout handler, for checking the
 * modem status signals.
 */
static void sa1100_timeout(unsigned long data)
{
    struct sa1100_port *sport = (struct sa1100_port *)data;
    unsigned long flags;

    if (sport->port.state) {
        spin_lock_irqsave(&sport->port.lock, flags);
        sa1100_mctrl_check(sport);
        spin_unlock_irqrestore(&sport->port.lock, flags);

        mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
    }
}

/*
 * interrupts disabled on entry
 */
static void sa1100_stop_tx(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    u32 utcr3;

    utcr3 = UART_GET_UTCR3(sport);
    UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_TIE);
    sport->port.read_status_mask &= ~UTSR0_TO_SM(UTSR0_TFS);
}

/*
 * port locked and interrupts disabled
 */
static void sa1100_start_tx(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    u32 utcr3;

    utcr3 = UART_GET_UTCR3(sport);
    sport->port.read_status_mask |= UTSR0_TO_SM(UTSR0_TFS);
    UART_PUT_UTCR3(sport, utcr3 | UTCR3_TIE);
}

/*
 * Interrupts enabled
 */
static void sa1100_stop_rx(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    u32 utcr3;

    utcr3 = UART_GET_UTCR3(sport);
    UART_PUT_UTCR3(sport, utcr3 & ~UTCR3_RIE);
}

/*
 * Set the modem control timer to fire immediately.
 */
static void sa1100_enable_ms(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    mod_timer(&sport->timer, jiffies);
}

static void
sa1100_rx_chars(struct sa1100_port *sport)
{
    struct tty_struct *tty = sport->port.state->port.tty;
    unsigned int status, ch, flg;

    status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
         UTSR0_TO_SM(UART_GET_UTSR0(sport));
    while (status & UTSR1_TO_SM(UTSR1_RNE)) {
        ch = UART_GET_CHAR(sport);

        sport->port.icount.rx++;

        flg = TTY_NORMAL;

        /*
         * note that the error handling code is
         * out of the main execution path
         */
        if (status & UTSR1_TO_SM(UTSR1_PRE | UTSR1_FRE | UTSR1_ROR)) {
            if (status & UTSR1_TO_SM(UTSR1_PRE))
                sport->port.icount.parity++;
            else if (status & UTSR1_TO_SM(UTSR1_FRE))
                sport->port.icount.frame++;
            if (status & UTSR1_TO_SM(UTSR1_ROR))
                sport->port.icount.overrun++;

            status &= sport->port.read_status_mask;

            if (status & UTSR1_TO_SM(UTSR1_PRE))
                flg = TTY_PARITY;
            else if (status & UTSR1_TO_SM(UTSR1_FRE))
                flg = TTY_FRAME;

#ifdef SUPPORT_SYSRQ
            sport->port.sysrq = 0;
#endif
        }

        if (uart_handle_sysrq_char(&sport->port, ch))
            goto ignore_char;

        uart_insert_char(&sport->port, status, UTSR1_TO_SM(UTSR1_ROR), ch, flg);

    ignore_char:
        status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |
             UTSR0_TO_SM(UART_GET_UTSR0(sport));
    }
    tty_flip_buffer_push(tty);
}

static void sa1100_tx_chars(struct sa1100_port *sport)
{
    struct circ_buf *xmit = &sport->port.state->xmit;

    if (sport->port.x_char) {
        UART_PUT_CHAR(sport, sport->port.x_char);
        sport->port.icount.tx++;
        sport->port.x_char = 0;
        return;
    }

    /*
     * Check the modem control lines before
     * transmitting anything.
     */
    sa1100_mctrl_check(sport);

    if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
        sa1100_stop_tx(&sport->port);
        return;
    }

    /*
     * Tried using FIFO (not checking TNF) for fifo fill:
     * still had the '4 bytes repeated' problem.
     */
    while (UART_GET_UTSR1(sport) & UTSR1_TNF) {
        UART_PUT_CHAR(sport, xmit->buf[xmit->tail]);
        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
        sport->port.icount.tx++;
        if (uart_circ_empty(xmit))
            break;
    }

    if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
        uart_write_wakeup(&sport->port);

    if (uart_circ_empty(xmit))
        sa1100_stop_tx(&sport->port);
}

static irqreturn_t sa1100_int(int irq, void *dev_id)
{
    struct sa1100_port *sport = dev_id;
    unsigned int status, pass_counter = 0;

    spin_lock(&sport->port.lock);
    status = UART_GET_UTSR0(sport);
    status &= SM_TO_UTSR0(sport->port.read_status_mask) | ~UTSR0_TFS;
    do {
        if (status & (UTSR0_RFS | UTSR0_RID)) {
            /* Clear the receiver idle bit, if set */
            if (status & UTSR0_RID)
                UART_PUT_UTSR0(sport, UTSR0_RID);
            sa1100_rx_chars(sport);
        }

        /* Clear the relevant break bits */
        if (status & (UTSR0_RBB | UTSR0_REB))
            UART_PUT_UTSR0(sport, status & (UTSR0_RBB | UTSR0_REB));

        if (status & UTSR0_RBB)
            sport->port.icount.brk++;

        if (status & UTSR0_REB)
            uart_handle_break(&sport->port);

        if (status & UTSR0_TFS)
            sa1100_tx_chars(sport);
        if (pass_counter++ > SA1100_ISR_PASS_LIMIT)
            break;
        status = UART_GET_UTSR0(sport);
        status &= SM_TO_UTSR0(sport->port.read_status_mask) |
              ~UTSR0_TFS;
    } while (status & (UTSR0_TFS | UTSR0_RFS | UTSR0_RID));
    spin_unlock(&sport->port.lock);

    return IRQ_HANDLED;
}

/*
 * Return TIOCSER_TEMT when transmitter is not busy.
 */
static unsigned int sa1100_tx_empty(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    return UART_GET_UTSR1(sport) & UTSR1_TBY ? 0 : TIOCSER_TEMT;
}

static unsigned int sa1100_get_mctrl(struct uart_port *port)
{
    return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}

static void sa1100_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}

/*
 * Interrupts always disabled.
 */
static void sa1100_break_ctl(struct uart_port *port, int break_state)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    unsigned long flags;
    unsigned int utcr3;

    spin_lock_irqsave(&sport->port.lock, flags);
    utcr3 = UART_GET_UTCR3(sport);
    if (break_state == -1)
        utcr3 |= UTCR3_BRK;
    else
        utcr3 &= ~UTCR3_BRK;
    UART_PUT_UTCR3(sport, utcr3);
    spin_unlock_irqrestore(&sport->port.lock, flags);
}

static int sa1100_startup(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    int retval;

    /*
     * Allocate the IRQ
     */
    retval = request_irq(sport->port.irq, sa1100_int, 0,
                 "sa11x0-uart", sport);
    if (retval)
        return retval;

    /*
     * Finally, clear and enable interrupts
     */
    UART_PUT_UTSR0(sport, -1);
    UART_PUT_UTCR3(sport, UTCR3_RXE | UTCR3_TXE | UTCR3_RIE);

    /*
     * Enable modem status interrupts
     */
    spin_lock_irq(&sport->port.lock);
    sa1100_enable_ms(&sport->port);
    spin_unlock_irq(&sport->port.lock);

    return 0;
}

static void sa1100_shutdown(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    /*
     * Stop our timer.
     */
    del_timer_sync(&sport->timer);

    /*
     * Free the interrupt
     */
    free_irq(sport->port.irq, sport);

    /*
     * Disable all interrupts, port and break condition.
     */
    UART_PUT_UTCR3(sport, 0);
}

static void
sa1100_set_termios(struct uart_port *port, struct ktermios *termios,
           struct ktermios *old)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    unsigned long flags;
    unsigned int utcr0, old_utcr3, baud, quot;
    unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;

    /*
     * 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)
        utcr0 = UTCR0_DSS;
    else
        utcr0 = 0;

    if (termios->c_cflag & CSTOPB)
        utcr0 |= UTCR0_SBS;
    if (termios->c_cflag & PARENB) {
        utcr0 |= UTCR0_PE;
        if (!(termios->c_cflag & PARODD))
            utcr0 |= UTCR0_OES;
    }

    /*
     * 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 &= UTSR0_TO_SM(UTSR0_TFS);
    sport->port.read_status_mask |= UTSR1_TO_SM(UTSR1_ROR);
    if (termios->c_iflag & INPCK)
        sport->port.read_status_mask |=
                UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
    if (termios->c_iflag & (BRKINT | PARMRK))
        sport->port.read_status_mask |=
                UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);

    /*
     * Characters to ignore
     */
    sport->port.ignore_status_mask = 0;
    if (termios->c_iflag & IGNPAR)
        sport->port.ignore_status_mask |=
                UTSR1_TO_SM(UTSR1_FRE | UTSR1_PRE);
    if (termios->c_iflag & IGNBRK) {
        sport->port.ignore_status_mask |=
                UTSR0_TO_SM(UTSR0_RBB | UTSR0_REB);
        /*
         * 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 |=
                UTSR1_TO_SM(UTSR1_ROR);
    }

    del_timer_sync(&sport->timer);

    /*
     * Update the per-port timeout.
     */
    uart_update_timeout(port, termios->c_cflag, baud);

    /*
     * disable interrupts and drain transmitter
     */
    old_utcr3 = UART_GET_UTCR3(sport);
    UART_PUT_UTCR3(sport, old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE));

    while (UART_GET_UTSR1(sport) & UTSR1_TBY)
        barrier();

    /* then, disable everything */
    UART_PUT_UTCR3(sport, 0);

    /* set the parity, stop bits and data size */
    UART_PUT_UTCR0(sport, utcr0);

    /* set the baud rate */
    quot -= 1;
    UART_PUT_UTCR1(sport, ((quot & 0xf00) >> 8));
    UART_PUT_UTCR2(sport, (quot & 0xff));

    UART_PUT_UTSR0(sport, -1);

    UART_PUT_UTCR3(sport, old_utcr3);

    if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
        sa1100_enable_ms(&sport->port);

    spin_unlock_irqrestore(&sport->port.lock, flags);
}

static const char *sa1100_type(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    return sport->port.type == PORT_SA1100 ? "SA1100" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'.
 */
static void sa1100_release_port(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
}

/*
 * Request the memory region(s) being used by 'port'.
 */
static int sa1100_request_port(struct uart_port *port)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
            "sa11x0-uart") != NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void sa1100_config_port(struct uart_port *port, int flags)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    if (flags & UART_CONFIG_TYPE &&
        sa1100_request_port(&sport->port) == 0)
        sport->port.type = PORT_SA1100;
}

/*
 * Verify the new serial_struct (for TIOCSSERIAL).
 * The only change we allow are to the flags and type, and
 * even then only between PORT_SA1100 and PORT_UNKNOWN
 */
static int
sa1100_verify_port(struct uart_port *port, struct serial_struct *ser)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;
    int ret = 0;

    if (ser->type != PORT_UNKNOWN && ser->type != PORT_SA1100)
        ret = -EINVAL;
    if (sport->port.irq != ser->irq)
        ret = -EINVAL;
    if (ser->io_type != SERIAL_IO_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 sa1100_pops = {
    .tx_empty   = sa1100_tx_empty,
    .set_mctrl  = sa1100_set_mctrl,
    .get_mctrl  = sa1100_get_mctrl,
    .stop_tx    = sa1100_stop_tx,
    .start_tx   = sa1100_start_tx,
    .stop_rx    = sa1100_stop_rx,
    .enable_ms  = sa1100_enable_ms,
    .break_ctl  = sa1100_break_ctl,
    .startup    = sa1100_startup,
    .shutdown   = sa1100_shutdown,
    .set_termios    = sa1100_set_termios,
    .type       = sa1100_type,
    .release_port   = sa1100_release_port,
    .request_port   = sa1100_request_port,
    .config_port    = sa1100_config_port,
    .verify_port    = sa1100_verify_port,
};

static struct sa1100_port sa1100_ports[NR_PORTS];

/*
 * Setup the SA1100 serial ports.  Note that we don't include the IrDA
 * port here since we have our own SIR/FIR driver (see drivers/net/irda)
 *
 * Note also that we support "console=ttySAx" 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.
 *
 * Note that NanoEngine UART3 becomes UART2, and UART2 is no longer
 * used here.
 */
static void __init sa1100_init_ports(void)
{
    static int first = 1;
    int i;

    if (!first)
        return;
    first = 0;

    for (i = 0; i < NR_PORTS; i++) {
        sa1100_ports[i].port.uartclk   = 3686400;
        sa1100_ports[i].port.ops       = &sa1100_pops;
        sa1100_ports[i].port.fifosize  = 8;
        sa1100_ports[i].port.line      = i;
        sa1100_ports[i].port.iotype    = UPIO_MEM;
        init_timer(&sa1100_ports[i].timer);
        sa1100_ports[i].timer.function = sa1100_timeout;
        sa1100_ports[i].timer.data     = (unsigned long)&sa1100_ports[i];
    }

    /*
     * make transmit lines outputs, so that when the port
     * is closed, the output is in the MARK state.
     */
    PPDR |= PPC_TXD1 | PPC_TXD3;
    PPSR |= PPC_TXD1 | PPC_TXD3;
}

void __devinit sa1100_register_uart_fns(struct sa1100_port_fns *fns)
{
    if (fns->get_mctrl)
        sa1100_pops.get_mctrl = fns->get_mctrl;
    if (fns->set_mctrl)
        sa1100_pops.set_mctrl = fns->set_mctrl;

    sa1100_pops.pm       = fns->pm;
    sa1100_pops.set_wake = fns->set_wake;
}

void __init sa1100_register_uart(int idx, int port)
{
    if (idx >= NR_PORTS) {
        printk(KERN_ERR "%s: bad index number %d\n", __func__, idx);
        return;
    }

    switch (port) {
    case 1:
        sa1100_ports[idx].port.membase = (void __iomem *)&Ser1UTCR0;
        sa1100_ports[idx].port.mapbase = _Ser1UTCR0;
        sa1100_ports[idx].port.irq     = IRQ_Ser1UART;
        sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
        break;

    case 2:
        sa1100_ports[idx].port.membase = (void __iomem *)&Ser2UTCR0;
        sa1100_ports[idx].port.mapbase = _Ser2UTCR0;
        sa1100_ports[idx].port.irq     = IRQ_Ser2ICP;
        sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
        break;

    case 3:
        sa1100_ports[idx].port.membase = (void __iomem *)&Ser3UTCR0;
        sa1100_ports[idx].port.mapbase = _Ser3UTCR0;
        sa1100_ports[idx].port.irq     = IRQ_Ser3UART;
        sa1100_ports[idx].port.flags   = UPF_BOOT_AUTOCONF;
        break;

    default:
        printk(KERN_ERR "%s: bad port number %d\n", __func__, port);
    }
}


#ifdef CONFIG_SERIAL_SA1100_CONSOLE
static void sa1100_console_putchar(struct uart_port *port, int ch)
{
    struct sa1100_port *sport = (struct sa1100_port *)port;

    while (!(UART_GET_UTSR1(sport) & UTSR1_TNF))
        barrier();
    UART_PUT_CHAR(sport, ch);
}

/*
 * Interrupts are disabled on entering
 */
static void
sa1100_console_write(struct console *co, const char *s, unsigned int count)
{
    struct sa1100_port *sport = &sa1100_ports[co->index];
    unsigned int old_utcr3, status;

    /*
     *  First, save UTCR3 and then disable interrupts
     */
    old_utcr3 = UART_GET_UTCR3(sport);
    UART_PUT_UTCR3(sport, (old_utcr3 & ~(UTCR3_RIE | UTCR3_TIE)) |
                UTCR3_TXE);

    uart_console_write(&sport->port, s, count, sa1100_console_putchar);

    /*
     *  Finally, wait for transmitter to become empty
     *  and restore UTCR3
     */
    do {
        status = UART_GET_UTSR1(sport);
    } while (status & UTSR1_TBY);
    UART_PUT_UTCR3(sport, old_utcr3);
}

/*
 * If the port was already initialised (eg, by a boot loader),
 * try to determine the current setup.
 */
static void __init
sa1100_console_get_options(struct sa1100_port *sport, int *baud,
               int *parity, int *bits)
{
    unsigned int utcr3;

    utcr3 = UART_GET_UTCR3(sport) & (UTCR3_RXE | UTCR3_TXE);
    if (utcr3 == (UTCR3_RXE | UTCR3_TXE)) {
        /* ok, the port was enabled */
        unsigned int utcr0, quot;

        utcr0 = UART_GET_UTCR0(sport);

        *parity = 'n';
        if (utcr0 & UTCR0_PE) {
            if (utcr0 & UTCR0_OES)
                *parity = 'e';
            else
                *parity = 'o';
        }

        if (utcr0 & UTCR0_DSS)
            *bits = 8;
        else
            *bits = 7;

        quot = UART_GET_UTCR2(sport) | UART_GET_UTCR1(sport) << 8;
        quot &= 0xfff;
        *baud = sport->port.uartclk / (16 * (quot + 1));
    }
}

static int __init
sa1100_console_setup(struct console *co, char *options)
{
    struct sa1100_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 >= NR_PORTS)
        co->index = 0;
    sport = &sa1100_ports[co->index];

    if (options)
        uart_parse_options(options, &baud, &parity, &bits, &flow);
    else
        sa1100_console_get_options(sport, &baud, &parity, &bits);

    return uart_set_options(&sport->port, co, baud, parity, bits, flow);
}

static struct uart_driver sa1100_reg;
static struct console sa1100_console = {
    .name       = "ttySA",
    .write      = sa1100_console_write,
    .device     = uart_console_device,
    .setup      = sa1100_console_setup,
    .flags      = CON_PRINTBUFFER,
    .index      = -1,
    .data       = &sa1100_reg,
};

static int __init sa1100_rs_console_init(void)
{
    sa1100_init_ports();
    register_console(&sa1100_console);
    return 0;
}
console_initcall(sa1100_rs_console_init);

#define SA1100_CONSOLE  &sa1100_console
#else
#define SA1100_CONSOLE  NULL
#endif

static struct uart_driver sa1100_reg = {
    .owner          = THIS_MODULE,
    .driver_name        = "ttySA",
    .dev_name       = "ttySA",
    .major          = SERIAL_SA1100_MAJOR,
    .minor          = MINOR_START,
    .nr         = NR_PORTS,
    .cons           = SA1100_CONSOLE,
};

static int sa1100_serial_suspend(struct platform_device *dev, pm_message_t state)
{
    struct sa1100_port *sport = platform_get_drvdata(dev);

    if (sport)
        uart_suspend_port(&sa1100_reg, &sport->port);

    return 0;
}

static int sa1100_serial_resume(struct platform_device *dev)
{
    struct sa1100_port *sport = platform_get_drvdata(dev);

    if (sport)
        uart_resume_port(&sa1100_reg, &sport->port);

    return 0;
}

static int sa1100_serial_probe(struct platform_device *dev)
{
    struct resource *res = dev->resource;
    int i;

    for (i = 0; i < dev->num_resources; i++, res++)
        if (res->flags & IORESOURCE_MEM)
            break;

    if (i < dev->num_resources) {
        for (i = 0; i < NR_PORTS; i++) {
            if (sa1100_ports[i].port.mapbase != res->start)
                continue;

            sa1100_ports[i].port.dev = &dev->dev;
            uart_add_one_port(&sa1100_reg, &sa1100_ports[i].port);
            platform_set_drvdata(dev, &sa1100_ports[i]);
            break;
        }
    }

    return 0;
}

static int sa1100_serial_remove(struct platform_device *pdev)
{
    struct sa1100_port *sport = platform_get_drvdata(pdev);

    platform_set_drvdata(pdev, NULL);

    if (sport)
        uart_remove_one_port(&sa1100_reg, &sport->port);

    return 0;
}

static struct platform_driver sa11x0_serial_driver = {
    .probe      = sa1100_serial_probe,
    .remove     = sa1100_serial_remove,
    .suspend    = sa1100_serial_suspend,
    .resume     = sa1100_serial_resume,
    .driver     = {
        .name   = "sa11x0-uart",
        .owner  = THIS_MODULE,
    },
};

static int __init sa1100_serial_init(void)
{
    int ret;

    printk(KERN_INFO "Serial: SA11x0 driver\n");

    sa1100_init_ports();

    ret = uart_register_driver(&sa1100_reg);
    if (ret == 0) {
        ret = platform_driver_register(&sa11x0_serial_driver);
        if (ret)
            uart_unregister_driver(&sa1100_reg);
    }
    return ret;
}

static void __exit sa1100_serial_exit(void)
{
    platform_driver_unregister(&sa11x0_serial_driver);
    uart_unregister_driver(&sa1100_reg);
}

module_init(sa1100_serial_init);
module_exit(sa1100_serial_exit);

MODULE_AUTHOR("Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("SA1100 generic serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_SA1100_MAJOR);
MODULE_ALIAS("platform:sa11x0-uart");