pnx8xxx_uart.c

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/*
 * UART driver for PNX8XXX SoCs
 *
 * Author: Per Hallsmark [email protected]
 * Ported to 2.6 kernel by EmbeddedAlley
 * Reworked by Vitaly Wool <[email protected]>
 *
 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 * Copyright (C) 2000 Deep Blue Solutions Ltd.
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of
 * any kind, whether express or implied.
 *
 */

#if defined(CONFIG_SERIAL_PNX8XXX_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/device.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/serial_pnx8xxx.h>

#include <asm/io.h>
#include <asm/irq.h>

/* We'll be using StrongARM sa1100 serial port major/minor */
#define SERIAL_PNX8XXX_MAJOR    204
#define MINOR_START     5

#define NR_PORTS        2

#define PNX8XXX_ISR_PASS_LIMIT  256

/*
 * Convert from ignore_status_mask or read_status_mask to FIFO
 * and interrupt status bits
 */
#define SM_TO_FIFO(x)   ((x) >> 10)
#define SM_TO_ISTAT(x)  ((x) & 0x000001ff)
#define FIFO_TO_SM(x)   ((x) << 10)
#define ISTAT_TO_SM(x)  ((x) & 0x000001ff)

/*
 * This is the size of our serial port register set.
 */
#define UART_PORT_SIZE  0x1000

/*
 * 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)

extern struct pnx8xxx_port pnx8xxx_ports[];

static inline int serial_in(struct pnx8xxx_port *sport, int offset)
{
    return (__raw_readl(sport->port.membase + offset));
}

static inline void serial_out(struct pnx8xxx_port *sport, int offset, int value)
{
    __raw_writel(value, sport->port.membase + offset);
}

/*
 * Handle any change of modem status signal since we were last called.
 */
static void pnx8xxx_mctrl_check(struct pnx8xxx_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 pnx8xxx_timeout(unsigned long data)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)data;
    unsigned long flags;

    if (sport->port.state) {
        spin_lock_irqsave(&sport->port.lock, flags);
        pnx8xxx_mctrl_check(sport);
        spin_unlock_irqrestore(&sport->port.lock, flags);

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

/*
 * interrupts disabled on entry
 */
static void pnx8xxx_stop_tx(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    u32 ien;

    /* Disable TX intr */
    ien = serial_in(sport, PNX8XXX_IEN);
    serial_out(sport, PNX8XXX_IEN, ien & ~PNX8XXX_UART_INT_ALLTX);

    /* Clear all pending TX intr */
    serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLTX);
}

/*
 * interrupts may not be disabled on entry
 */
static void pnx8xxx_start_tx(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    u32 ien;

    /* Clear all pending TX intr */
    serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLTX);

    /* Enable TX intr */
    ien = serial_in(sport, PNX8XXX_IEN);
    serial_out(sport, PNX8XXX_IEN, ien | PNX8XXX_UART_INT_ALLTX);
}

/*
 * Interrupts enabled
 */
static void pnx8xxx_stop_rx(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    u32 ien;

    /* Disable RX intr */
    ien = serial_in(sport, PNX8XXX_IEN);
    serial_out(sport, PNX8XXX_IEN, ien & ~PNX8XXX_UART_INT_ALLRX);

    /* Clear all pending RX intr */
    serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX);
}

/*
 * Set the modem control timer to fire immediately.
 */
static void pnx8xxx_enable_ms(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;

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

static void pnx8xxx_rx_chars(struct pnx8xxx_port *sport)
{
    struct tty_struct *tty = sport->port.state->port.tty;
    unsigned int status, ch, flg;

    status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
         ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
    while (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFIFO)) {
        ch = serial_in(sport, PNX8XXX_FIFO) & 0xff;

        sport->port.icount.rx++;

        flg = TTY_NORMAL;

        /*
         * note that the error handling code is
         * out of the main execution path
         */
        if (status & (FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE |
                    PNX8XXX_UART_FIFO_RXPAR |
                    PNX8XXX_UART_FIFO_RXBRK) |
                  ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))) {
            if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXBRK)) {
                status &= ~(FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
                    FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR));
                sport->port.icount.brk++;
                if (uart_handle_break(&sport->port))
                    goto ignore_char;
            } else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
                sport->port.icount.parity++;
            else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
                sport->port.icount.frame++;
            if (status & ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))
                sport->port.icount.overrun++;

            status &= sport->port.read_status_mask;

            if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR))
                flg = TTY_PARITY;
            else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE))
                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,
                ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN), ch, flg);

    ignore_char:
        serial_out(sport, PNX8XXX_LCR, serial_in(sport, PNX8XXX_LCR) |
                PNX8XXX_UART_LCR_RX_NEXT);
        status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) |
             ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT));
    }
    tty_flip_buffer_push(tty);
}

static void pnx8xxx_tx_chars(struct pnx8xxx_port *sport)
{
    struct circ_buf *xmit = &sport->port.state->xmit;

    if (sport->port.x_char) {
        serial_out(sport, PNX8XXX_FIFO, sport->port.x_char);
        sport->port.icount.tx++;
        sport->port.x_char = 0;
        return;
    }

    /*
     * Check the modem control lines before
     * transmitting anything.
     */
    pnx8xxx_mctrl_check(sport);

    if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
        pnx8xxx_stop_tx(&sport->port);
        return;
    }

    /*
     * TX while bytes available
     */
    while (((serial_in(sport, PNX8XXX_FIFO) &
                    PNX8XXX_UART_FIFO_TXFIFO) >> 16) < 16) {
        serial_out(sport, PNX8XXX_FIFO, 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))
        pnx8xxx_stop_tx(&sport->port);
}

static irqreturn_t pnx8xxx_int(int irq, void *dev_id)
{
    struct pnx8xxx_port *sport = dev_id;
    unsigned int status;

    spin_lock(&sport->port.lock);
    /* Get the interrupts */
    status  = serial_in(sport, PNX8XXX_ISTAT) & serial_in(sport, PNX8XXX_IEN);

    /* Byte or break signal received */
    if (status & (PNX8XXX_UART_INT_RX | PNX8XXX_UART_INT_BREAK))
        pnx8xxx_rx_chars(sport);

    /* TX holding register empty - transmit a byte */
    if (status & PNX8XXX_UART_INT_TX)
        pnx8xxx_tx_chars(sport);

    /* Clear the ISTAT register */
    serial_out(sport, PNX8XXX_ICLR, status);

    spin_unlock(&sport->port.lock);
    return IRQ_HANDLED;
}

/*
 * Return TIOCSER_TEMT when transmitter is not busy.
 */
static unsigned int pnx8xxx_tx_empty(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;

    return serial_in(sport, PNX8XXX_FIFO) & PNX8XXX_UART_FIFO_TXFIFO_STA ? 0 : TIOCSER_TEMT;
}

static unsigned int pnx8xxx_get_mctrl(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    unsigned int mctrl = TIOCM_DSR;
    unsigned int msr;

    /* REVISIT */

    msr = serial_in(sport, PNX8XXX_MCR);

    mctrl |= msr & PNX8XXX_UART_MCR_CTS ? TIOCM_CTS : 0;
    mctrl |= msr & PNX8XXX_UART_MCR_DCD ? TIOCM_CAR : 0;

    return mctrl;
}

static void pnx8xxx_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
#if 0   /* FIXME */
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    unsigned int msr;
#endif
}

/*
 * Interrupts always disabled.
 */
static void pnx8xxx_break_ctl(struct uart_port *port, int break_state)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    unsigned long flags;
    unsigned int lcr;

    spin_lock_irqsave(&sport->port.lock, flags);
    lcr = serial_in(sport, PNX8XXX_LCR);
    if (break_state == -1)
        lcr |= PNX8XXX_UART_LCR_TXBREAK;
    else
        lcr &= ~PNX8XXX_UART_LCR_TXBREAK;
    serial_out(sport, PNX8XXX_LCR, lcr);
    spin_unlock_irqrestore(&sport->port.lock, flags);
}

static int pnx8xxx_startup(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    int retval;

    /*
     * Allocate the IRQ
     */
    retval = request_irq(sport->port.irq, pnx8xxx_int, 0,
                 "pnx8xxx-uart", sport);
    if (retval)
        return retval;

    /*
     * Finally, clear and enable interrupts
     */

    serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX |
                 PNX8XXX_UART_INT_ALLTX);

    serial_out(sport, PNX8XXX_IEN, serial_in(sport, PNX8XXX_IEN) |
                PNX8XXX_UART_INT_ALLRX |
                PNX8XXX_UART_INT_ALLTX);

    /*
     * Enable modem status interrupts
     */
    spin_lock_irq(&sport->port.lock);
    pnx8xxx_enable_ms(&sport->port);
    spin_unlock_irq(&sport->port.lock);

    return 0;
}

static void pnx8xxx_shutdown(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    int lcr;

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

    /*
     * Disable all interrupts
     */
    serial_out(sport, PNX8XXX_IEN, 0);

    /*
     * Reset the Tx and Rx FIFOS, disable the break condition
     */
    lcr = serial_in(sport, PNX8XXX_LCR);
    lcr &= ~PNX8XXX_UART_LCR_TXBREAK;
    lcr |= PNX8XXX_UART_LCR_TX_RST | PNX8XXX_UART_LCR_RX_RST;
    serial_out(sport, PNX8XXX_LCR, lcr);

    /*
     * Clear all interrupts
     */
    serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX |
                 PNX8XXX_UART_INT_ALLTX);

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

static void
pnx8xxx_set_termios(struct uart_port *port, struct ktermios *termios,
           struct ktermios *old)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    unsigned long flags;
    unsigned int lcr_fcr, old_ien, 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)
        lcr_fcr = PNX8XXX_UART_LCR_8BIT;
    else
        lcr_fcr = 0;

    if (termios->c_cflag & CSTOPB)
        lcr_fcr |= PNX8XXX_UART_LCR_2STOPB;
    if (termios->c_cflag & PARENB) {
        lcr_fcr |= PNX8XXX_UART_LCR_PAREN;
        if (!(termios->c_cflag & PARODD))
            lcr_fcr |= PNX8XXX_UART_LCR_PAREVN;
    }

    /*
     * 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 = ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN) |
                ISTAT_TO_SM(PNX8XXX_UART_INT_EMPTY) |
                ISTAT_TO_SM(PNX8XXX_UART_INT_RX);
    if (termios->c_iflag & INPCK)
        sport->port.read_status_mask |=
            FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
            FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR);
    if (termios->c_iflag & (BRKINT | PARMRK))
        sport->port.read_status_mask |=
            ISTAT_TO_SM(PNX8XXX_UART_INT_BREAK);

    /*
     * Characters to ignore
     */
    sport->port.ignore_status_mask = 0;
    if (termios->c_iflag & IGNPAR)
        sport->port.ignore_status_mask |=
            FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) |
            FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR);
    if (termios->c_iflag & IGNBRK) {
        sport->port.ignore_status_mask |=
            ISTAT_TO_SM(PNX8XXX_UART_INT_BREAK);
        /*
         * 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 |=
                ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN);
    }

    /*
     * ignore all characters if CREAD is not set
     */
    if ((termios->c_cflag & CREAD) == 0)
        sport->port.ignore_status_mask |=
            ISTAT_TO_SM(PNX8XXX_UART_INT_RX);

    del_timer_sync(&sport->timer);

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

    /*
     * disable interrupts and drain transmitter
     */
    old_ien = serial_in(sport, PNX8XXX_IEN);
    serial_out(sport, PNX8XXX_IEN, old_ien & ~(PNX8XXX_UART_INT_ALLTX |
                    PNX8XXX_UART_INT_ALLRX));

    while (serial_in(sport, PNX8XXX_FIFO) & PNX8XXX_UART_FIFO_TXFIFO_STA)
        barrier();

    /* then, disable everything */
    serial_out(sport, PNX8XXX_IEN, 0);

    /* Reset the Rx and Tx FIFOs too */
    lcr_fcr |= PNX8XXX_UART_LCR_TX_RST;
    lcr_fcr |= PNX8XXX_UART_LCR_RX_RST;

    /* set the parity, stop bits and data size */
    serial_out(sport, PNX8XXX_LCR, lcr_fcr);

    /* set the baud rate */
    quot -= 1;
    serial_out(sport, PNX8XXX_BAUD, quot);

    serial_out(sport, PNX8XXX_ICLR, -1);

    serial_out(sport, PNX8XXX_IEN, old_ien);

    if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
        pnx8xxx_enable_ms(&sport->port);

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

static const char *pnx8xxx_type(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;

    return sport->port.type == PORT_PNX8XXX ? "PNX8XXX" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'.
 */
static void pnx8xxx_release_port(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;

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

/*
 * Request the memory region(s) being used by 'port'.
 */
static int pnx8xxx_request_port(struct uart_port *port)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
            "pnx8xxx-uart") != NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void pnx8xxx_config_port(struct uart_port *port, int flags)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;

    if (flags & UART_CONFIG_TYPE &&
        pnx8xxx_request_port(&sport->port) == 0)
        sport->port.type = PORT_PNX8XXX;
}

/*
 * Verify the new serial_struct (for TIOCSSERIAL).
 * The only change we allow are to the flags and type, and
 * even then only between PORT_PNX8XXX and PORT_UNKNOWN
 */
static int
pnx8xxx_verify_port(struct uart_port *port, struct serial_struct *ser)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    int ret = 0;

    if (ser->type != PORT_UNKNOWN && ser->type != PORT_PNX8XXX)
        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 pnx8xxx_pops = {
    .tx_empty   = pnx8xxx_tx_empty,
    .set_mctrl  = pnx8xxx_set_mctrl,
    .get_mctrl  = pnx8xxx_get_mctrl,
    .stop_tx    = pnx8xxx_stop_tx,
    .start_tx   = pnx8xxx_start_tx,
    .stop_rx    = pnx8xxx_stop_rx,
    .enable_ms  = pnx8xxx_enable_ms,
    .break_ctl  = pnx8xxx_break_ctl,
    .startup    = pnx8xxx_startup,
    .shutdown   = pnx8xxx_shutdown,
    .set_termios    = pnx8xxx_set_termios,
    .type       = pnx8xxx_type,
    .release_port   = pnx8xxx_release_port,
    .request_port   = pnx8xxx_request_port,
    .config_port    = pnx8xxx_config_port,
    .verify_port    = pnx8xxx_verify_port,
};


/*
 * Setup the PNX8XXX serial ports.
 *
 * Note also that we support "console=ttySx" where "x" is either 0 or 1.
 */
static void __init pnx8xxx_init_ports(void)
{
    static int first = 1;
    int i;

    if (!first)
        return;
    first = 0;

    for (i = 0; i < NR_PORTS; i++) {
        init_timer(&pnx8xxx_ports[i].timer);
        pnx8xxx_ports[i].timer.function = pnx8xxx_timeout;
        pnx8xxx_ports[i].timer.data     = (unsigned long)&pnx8xxx_ports[i];
        pnx8xxx_ports[i].port.ops = &pnx8xxx_pops;
    }
}

#ifdef CONFIG_SERIAL_PNX8XXX_CONSOLE

static void pnx8xxx_console_putchar(struct uart_port *port, int ch)
{
    struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port;
    int status;

    do {
        /* Wait for UART_TX register to empty */
        status = serial_in(sport, PNX8XXX_FIFO);
    } while (status & PNX8XXX_UART_FIFO_TXFIFO);
    serial_out(sport, PNX8XXX_FIFO, ch);
}

/*
 * Interrupts are disabled on entering
 */static void
pnx8xxx_console_write(struct console *co, const char *s, unsigned int count)
{
    struct pnx8xxx_port *sport = &pnx8xxx_ports[co->index];
    unsigned int old_ien, status;

    /*
     *  First, save IEN and then disable interrupts
     */
    old_ien = serial_in(sport, PNX8XXX_IEN);
    serial_out(sport, PNX8XXX_IEN, old_ien & ~(PNX8XXX_UART_INT_ALLTX |
                    PNX8XXX_UART_INT_ALLRX));

    uart_console_write(&sport->port, s, count, pnx8xxx_console_putchar);

    /*
     *  Finally, wait for transmitter to become empty
     *  and restore IEN
     */
    do {
        /* Wait for UART_TX register to empty */
        status = serial_in(sport, PNX8XXX_FIFO);
    } while (status & PNX8XXX_UART_FIFO_TXFIFO);

    /* Clear TX and EMPTY interrupt */
    serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_TX |
                 PNX8XXX_UART_INT_EMPTY);

    serial_out(sport, PNX8XXX_IEN, old_ien);
}

static int __init
pnx8xxx_console_setup(struct console *co, char *options)
{
    struct pnx8xxx_port *sport;
    int baud = 38400;
    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 = &pnx8xxx_ports[co->index];

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

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

static struct uart_driver pnx8xxx_reg;
static struct console pnx8xxx_console = {
    .name       = "ttyS",
    .write      = pnx8xxx_console_write,
    .device     = uart_console_device,
    .setup      = pnx8xxx_console_setup,
    .flags      = CON_PRINTBUFFER,
    .index      = -1,
    .data       = &pnx8xxx_reg,
};

static int __init pnx8xxx_rs_console_init(void)
{
    pnx8xxx_init_ports();
    register_console(&pnx8xxx_console);
    return 0;
}
console_initcall(pnx8xxx_rs_console_init);

#define PNX8XXX_CONSOLE &pnx8xxx_console
#else
#define PNX8XXX_CONSOLE NULL
#endif

static struct uart_driver pnx8xxx_reg = {
    .owner          = THIS_MODULE,
    .driver_name        = "ttyS",
    .dev_name       = "ttyS",
    .major          = SERIAL_PNX8XXX_MAJOR,
    .minor          = MINOR_START,
    .nr         = NR_PORTS,
    .cons           = PNX8XXX_CONSOLE,
};

static int pnx8xxx_serial_suspend(struct platform_device *pdev, pm_message_t state)
{
    struct pnx8xxx_port *sport = platform_get_drvdata(pdev);

    return uart_suspend_port(&pnx8xxx_reg, &sport->port);
}

static int pnx8xxx_serial_resume(struct platform_device *pdev)
{
    struct pnx8xxx_port *sport = platform_get_drvdata(pdev);

    return uart_resume_port(&pnx8xxx_reg, &sport->port);
}

static int pnx8xxx_serial_probe(struct platform_device *pdev)
{
    struct resource *res = pdev->resource;
    int i;

    for (i = 0; i < pdev->num_resources; i++, res++) {
        if (!(res->flags & IORESOURCE_MEM))
            continue;

        for (i = 0; i < NR_PORTS; i++) {
            if (pnx8xxx_ports[i].port.mapbase != res->start)
                continue;

            pnx8xxx_ports[i].port.dev = &pdev->dev;
            uart_add_one_port(&pnx8xxx_reg, &pnx8xxx_ports[i].port);
            platform_set_drvdata(pdev, &pnx8xxx_ports[i]);
            break;
        }
    }

    return 0;
}

static int pnx8xxx_serial_remove(struct platform_device *pdev)
{
    struct pnx8xxx_port *sport = platform_get_drvdata(pdev);

    platform_set_drvdata(pdev, NULL);

    if (sport)
        uart_remove_one_port(&pnx8xxx_reg, &sport->port);

    return 0;
}

static struct platform_driver pnx8xxx_serial_driver = {
    .driver     = {
        .name   = "pnx8xxx-uart",
        .owner  = THIS_MODULE,
    },
    .probe      = pnx8xxx_serial_probe,
    .remove     = pnx8xxx_serial_remove,
    .suspend    = pnx8xxx_serial_suspend,
    .resume     = pnx8xxx_serial_resume,
};

static int __init pnx8xxx_serial_init(void)
{
    int ret;

    printk(KERN_INFO "Serial: PNX8XXX driver\n");

    pnx8xxx_init_ports();

    ret = uart_register_driver(&pnx8xxx_reg);
    if (ret == 0) {
        ret = platform_driver_register(&pnx8xxx_serial_driver);
        if (ret)
            uart_unregister_driver(&pnx8xxx_reg);
    }
    return ret;
}

static void __exit pnx8xxx_serial_exit(void)
{
    platform_driver_unregister(&pnx8xxx_serial_driver);
    uart_unregister_driver(&pnx8xxx_reg);
}

module_init(pnx8xxx_serial_init);
module_exit(pnx8xxx_serial_exit);

MODULE_AUTHOR("Embedded Alley Solutions, Inc.");
MODULE_DESCRIPTION("PNX8XXX SoCs serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_PNX8XXX_MAJOR);
MODULE_ALIAS("platform:pnx8xxx-uart");