bfin_uart.c

Go to the documentation of this file.

/*
 * Blackfin On-Chip Serial Driver
 *
 * Copyright 2006-2011 Analog Devices Inc.
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Licensed under the GPL-2 or later.
 */

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

#define DRIVER_NAME "bfin-uart"
#define pr_fmt(fmt) DRIVER_NAME ": " fmt

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/gfp.h>
#include <linux/io.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/gpio.h>
#include <linux/irq.h>
#include <linux/kgdb.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>

#include <asm/portmux.h>
#include <asm/cacheflush.h>
#include <asm/dma.h>
#include <asm/bfin_serial.h>

#ifdef CONFIG_SERIAL_BFIN_MODULE
# undef CONFIG_EARLY_PRINTK
#endif

#ifdef CONFIG_SERIAL_BFIN_MODULE
# undef CONFIG_EARLY_PRINTK
#endif

/* UART name and device definitions */
#define BFIN_SERIAL_DEV_NAME    "ttyBF"
#define BFIN_SERIAL_MAJOR   204
#define BFIN_SERIAL_MINOR   64

static struct bfin_serial_port *bfin_serial_ports[BFIN_UART_NR_PORTS];

#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
    defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)

# ifndef CONFIG_SERIAL_BFIN_PIO
#  error KGDB only support UART in PIO mode.
# endif

static int kgdboc_port_line;
static int kgdboc_break_enabled;
#endif
/*
 * Setup for console. Argument comes from the menuconfig
 */
#define DMA_RX_XCOUNT       512
#define DMA_RX_YCOUNT       (PAGE_SIZE / DMA_RX_XCOUNT)

#define DMA_RX_FLUSH_JIFFIES    (HZ / 50)

#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
#else
static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
#endif

static void bfin_serial_reset_irda(struct uart_port *port);

#if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
    defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    if (uart->cts_pin < 0)
        return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;

    /* CTS PIN is negative assertive. */
    if (UART_GET_CTS(uart))
        return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
    else
        return TIOCM_DSR | TIOCM_CAR;
}

static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    if (uart->rts_pin < 0)
        return;

    /* RTS PIN is negative assertive. */
    if (mctrl & TIOCM_RTS)
        UART_ENABLE_RTS(uart);
    else
        UART_DISABLE_RTS(uart);
}

/*
 * Handle any change of modem status signal.
 */
static irqreturn_t bfin_serial_mctrl_cts_int(int irq, void *dev_id)
{
    struct bfin_serial_port *uart = dev_id;
    unsigned int status = bfin_serial_get_mctrl(&uart->port);
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
    struct tty_struct *tty = uart->port.state->port.tty;

    UART_CLEAR_SCTS(uart);
    if (tty->hw_stopped) {
        if (status) {
            tty->hw_stopped = 0;
            uart_write_wakeup(&uart->port);
        }
    } else {
        if (!status)
            tty->hw_stopped = 1;
    }
#endif
    uart_handle_cts_change(&uart->port, status & TIOCM_CTS);

    return IRQ_HANDLED;
}
#else
static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
{
    return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
}

static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
#endif

/*
 * interrupts are disabled on entry
 */
static void bfin_serial_stop_tx(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_SERIAL_BFIN_DMA
    struct circ_buf *xmit = &uart->port.state->xmit;
#endif

    while (!(UART_GET_LSR(uart) & TEMT))
        cpu_relax();

#ifdef CONFIG_SERIAL_BFIN_DMA
    disable_dma(uart->tx_dma_channel);
    xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);
    uart->port.icount.tx += uart->tx_count;
    uart->tx_count = 0;
    uart->tx_done = 1;
#else
#if defined(CONFIG_BF54x) || defined(CONFIG_BF60x)
    /* Clear TFI bit */
    UART_PUT_LSR(uart, TFI);
#endif
    UART_CLEAR_IER(uart, ETBEI);
#endif
}

/*
 * port is locked and interrupts are disabled
 */
static void bfin_serial_start_tx(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    struct tty_struct *tty = uart->port.state->port.tty;

    /*
     * To avoid losting RX interrupt, we reset IR function
     * before sending data.
     */
    if (tty->termios.c_line == N_IRDA)
        bfin_serial_reset_irda(port);

#ifdef CONFIG_SERIAL_BFIN_DMA
    if (uart->tx_done)
        bfin_serial_dma_tx_chars(uart);
#else
    UART_SET_IER(uart, ETBEI);
    bfin_serial_tx_chars(uart);
#endif
}

/*
 * Interrupts are enabled
 */
static void bfin_serial_stop_rx(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

    UART_CLEAR_IER(uart, ERBFI);
}

/*
 * Set the modem control timer to fire immediately.
 */
static void bfin_serial_enable_ms(struct uart_port *port)
{
}


#if ANOMALY_05000363 && defined(CONFIG_SERIAL_BFIN_PIO)
# define UART_GET_ANOMALY_THRESHOLD(uart)    ((uart)->anomaly_threshold)
# define UART_SET_ANOMALY_THRESHOLD(uart, v) ((uart)->anomaly_threshold = (v))
#else
# define UART_GET_ANOMALY_THRESHOLD(uart)    0
# define UART_SET_ANOMALY_THRESHOLD(uart, v)
#endif

#ifdef CONFIG_SERIAL_BFIN_PIO
static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
{
    struct tty_struct *tty = NULL;
    unsigned int status, ch, flg;
    static struct timeval anomaly_start = { .tv_sec = 0 };

    status = UART_GET_LSR(uart);
    UART_CLEAR_LSR(uart);

    ch = UART_GET_CHAR(uart);
    uart->port.icount.rx++;

#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
    defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
    if (kgdb_connected && kgdboc_port_line == uart->port.line
        && kgdboc_break_enabled)
        if (ch == 0x3) {/* Ctrl + C */
            kgdb_breakpoint();
            return;
        }

    if (!uart->port.state || !uart->port.state->port.tty)
        return;
#endif
    tty = uart->port.state->port.tty;

    if (ANOMALY_05000363) {
        /* The BF533 (and BF561) family of processors have a nice anomaly
         * where they continuously generate characters for a "single" break.
         * We have to basically ignore this flood until the "next" valid
         * character comes across.  Due to the nature of the flood, it is
         * not possible to reliably catch bytes that are sent too quickly
         * after this break.  So application code talking to the Blackfin
         * which sends a break signal must allow at least 1.5 character
         * times after the end of the break for things to stabilize.  This
         * timeout was picked as it must absolutely be larger than 1
         * character time +/- some percent.  So 1.5 sounds good.  All other
         * Blackfin families operate properly.  Woo.
         */
        if (anomaly_start.tv_sec) {
            struct timeval curr;
            suseconds_t usecs;

            if ((~ch & (~ch + 1)) & 0xff)
                goto known_good_char;

            do_gettimeofday(&curr);
            if (curr.tv_sec - anomaly_start.tv_sec > 1)
                goto known_good_char;

            usecs = 0;
            if (curr.tv_sec != anomaly_start.tv_sec)
                usecs += USEC_PER_SEC;
            usecs += curr.tv_usec - anomaly_start.tv_usec;

            if (usecs > UART_GET_ANOMALY_THRESHOLD(uart))
                goto known_good_char;

            if (ch)
                anomaly_start.tv_sec = 0;
            else
                anomaly_start = curr;

            return;

 known_good_char:
            status &= ~BI;
            anomaly_start.tv_sec = 0;
        }
    }

    if (status & BI) {
        if (ANOMALY_05000363)
            if (bfin_revid() < 5)
                do_gettimeofday(&anomaly_start);
        uart->port.icount.brk++;
        if (uart_handle_break(&uart->port))
            goto ignore_char;
        status &= ~(PE | FE);
    }
    if (status & PE)
        uart->port.icount.parity++;
    if (status & OE)
        uart->port.icount.overrun++;
    if (status & FE)
        uart->port.icount.frame++;

    status &= uart->port.read_status_mask;

    if (status & BI)
        flg = TTY_BREAK;
    else if (status & PE)
        flg = TTY_PARITY;
    else if (status & FE)
        flg = TTY_FRAME;
    else
        flg = TTY_NORMAL;

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

    uart_insert_char(&uart->port, status, OE, ch, flg);

 ignore_char:
    tty_flip_buffer_push(tty);
}

static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
{
    struct circ_buf *xmit = &uart->port.state->xmit;

    if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
#if defined(CONFIG_BF54x) || defined(CONFIG_BF60x)
        /* Clear TFI bit */
        UART_PUT_LSR(uart, TFI);
#endif
        /* Anomaly notes:
         *  05000215 -  we always clear ETBEI within last UART TX
         *      interrupt to end a string. It is always set
         *      when start a new tx.
         */
        UART_CLEAR_IER(uart, ETBEI);
        return;
    }

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

    while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
        UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
        uart->port.icount.tx++;
    }

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

static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
{
    struct bfin_serial_port *uart = dev_id;

    while (UART_GET_LSR(uart) & DR)
        bfin_serial_rx_chars(uart);

    return IRQ_HANDLED;
}

static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
{
    struct bfin_serial_port *uart = dev_id;

    spin_lock(&uart->port.lock);
    if (UART_GET_LSR(uart) & THRE)
        bfin_serial_tx_chars(uart);
    spin_unlock(&uart->port.lock);

    return IRQ_HANDLED;
}
#endif

#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
{
    struct circ_buf *xmit = &uart->port.state->xmit;

    uart->tx_done = 0;

    if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
        uart->tx_count = 0;
        uart->tx_done = 1;
        return;
    }

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

    uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
    if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
        uart->tx_count = UART_XMIT_SIZE - xmit->tail;
    blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
                    (unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
    set_dma_config(uart->tx_dma_channel,
        set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
            INTR_ON_BUF,
            DIMENSION_LINEAR,
            DATA_SIZE_8,
            DMA_SYNC_RESTART));
    set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
    set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
    set_dma_x_modify(uart->tx_dma_channel, 1);
    SSYNC();
    enable_dma(uart->tx_dma_channel);

    UART_SET_IER(uart, ETBEI);
}

static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
{
    struct tty_struct *tty = uart->port.state->port.tty;
    int i, flg, status;

    status = UART_GET_LSR(uart);
    UART_CLEAR_LSR(uart);

    uart->port.icount.rx +=
        CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
        UART_XMIT_SIZE);

    if (status & BI) {
        uart->port.icount.brk++;
        if (uart_handle_break(&uart->port))
            goto dma_ignore_char;
        status &= ~(PE | FE);
    }
    if (status & PE)
        uart->port.icount.parity++;
    if (status & OE)
        uart->port.icount.overrun++;
    if (status & FE)
        uart->port.icount.frame++;

    status &= uart->port.read_status_mask;

    if (status & BI)
        flg = TTY_BREAK;
    else if (status & PE)
        flg = TTY_PARITY;
    else if (status & FE)
        flg = TTY_FRAME;
    else
        flg = TTY_NORMAL;

    for (i = uart->rx_dma_buf.tail; ; i++) {
        if (i >= UART_XMIT_SIZE)
            i = 0;
        if (i == uart->rx_dma_buf.head)
            break;
        if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
            uart_insert_char(&uart->port, status, OE,
                uart->rx_dma_buf.buf[i], flg);
    }

 dma_ignore_char:
    tty_flip_buffer_push(tty);
}

void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
{
    int x_pos, pos;

    dma_disable_irq_nosync(uart->rx_dma_channel);
    spin_lock_bh(&uart->rx_lock);

    /* 2D DMA RX buffer ring is used. Because curr_y_count and
     * curr_x_count can't be read as an atomic operation,
     * curr_y_count should be read before curr_x_count. When
     * curr_x_count is read, curr_y_count may already indicate
     * next buffer line. But, the position calculated here is
     * still indicate the old line. The wrong position data may
     * be smaller than current buffer tail, which cause garbages
     * are received if it is not prohibit.
     */
    uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
    x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
    uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
    if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
        uart->rx_dma_nrows = 0;
    x_pos = DMA_RX_XCOUNT - x_pos;
    if (x_pos == DMA_RX_XCOUNT)
        x_pos = 0;

    pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
    /* Ignore receiving data if new position is in the same line of
     * current buffer tail and small.
     */
    if (pos > uart->rx_dma_buf.tail ||
        uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
        uart->rx_dma_buf.head = pos;
        bfin_serial_dma_rx_chars(uart);
        uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
    }

    spin_unlock_bh(&uart->rx_lock);
    dma_enable_irq(uart->rx_dma_channel);

    mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
}

static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
{
    struct bfin_serial_port *uart = dev_id;
    struct circ_buf *xmit = &uart->port.state->xmit;

    spin_lock(&uart->port.lock);
    if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
        disable_dma(uart->tx_dma_channel);
        clear_dma_irqstat(uart->tx_dma_channel);
        /* Anomaly notes:
         *  05000215 -  we always clear ETBEI within last UART TX
         *      interrupt to end a string. It is always set
         *      when start a new tx.
         */
        UART_CLEAR_IER(uart, ETBEI);
        uart->port.icount.tx += uart->tx_count;
        if (!(xmit->tail == 0 && xmit->head == 0)) {
            xmit->tail = (xmit->tail + uart->tx_count) & (UART_XMIT_SIZE - 1);

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

        bfin_serial_dma_tx_chars(uart);
    }

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

static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
{
    struct bfin_serial_port *uart = dev_id;
    unsigned int irqstat;
    int x_pos, pos;

    spin_lock(&uart->rx_lock);
    irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
    clear_dma_irqstat(uart->rx_dma_channel);

    uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
    x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
    uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
    if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
        uart->rx_dma_nrows = 0;

    pos = uart->rx_dma_nrows * DMA_RX_XCOUNT;
    if (pos > uart->rx_dma_buf.tail ||
        uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
        uart->rx_dma_buf.head = pos;
        bfin_serial_dma_rx_chars(uart);
        uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
    }

    spin_unlock(&uart->rx_lock);

    return IRQ_HANDLED;
}
#endif

/*
 * Return TIOCSER_TEMT when transmitter is not busy.
 */
static unsigned int bfin_serial_tx_empty(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    unsigned int lsr;

    lsr = UART_GET_LSR(uart);
    if (lsr & TEMT)
        return TIOCSER_TEMT;
    else
        return 0;
}

static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    u32 lcr = UART_GET_LCR(uart);
    if (break_state)
        lcr |= SB;
    else
        lcr &= ~SB;
    UART_PUT_LCR(uart, lcr);
    SSYNC();
}

static int bfin_serial_startup(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

#ifdef CONFIG_SERIAL_BFIN_DMA
    dma_addr_t dma_handle;

    if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
        printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
        return -EBUSY;
    }

    if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
        printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
        free_dma(uart->rx_dma_channel);
        return -EBUSY;
    }

    set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
    set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);

    uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
    uart->rx_dma_buf.head = 0;
    uart->rx_dma_buf.tail = 0;
    uart->rx_dma_nrows = 0;

    set_dma_config(uart->rx_dma_channel,
        set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
                INTR_ON_ROW, DIMENSION_2D,
                DATA_SIZE_8,
                DMA_SYNC_RESTART));
    set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
    set_dma_x_modify(uart->rx_dma_channel, 1);
    set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
    set_dma_y_modify(uart->rx_dma_channel, 1);
    set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
    enable_dma(uart->rx_dma_channel);

    uart->rx_dma_timer.data = (unsigned long)(uart);
    uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
    uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
    add_timer(&(uart->rx_dma_timer));
#else
# if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
    defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
    if (kgdboc_port_line == uart->port.line && kgdboc_break_enabled)
        kgdboc_break_enabled = 0;
    else {
# endif
    if (request_irq(uart->rx_irq, bfin_serial_rx_int, 0,
         "BFIN_UART_RX", uart)) {
        printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
        return -EBUSY;
    }

    if (request_irq
        (uart->tx_irq, bfin_serial_tx_int, 0,
         "BFIN_UART_TX", uart)) {
        printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
        free_irq(uart->rx_irq, uart);
        return -EBUSY;
    }

# ifdef CONFIG_BF54x
    {
        /*
         * UART2 and UART3 on BF548 share interrupt PINs and DMA
         * controllers with SPORT2 and SPORT3. UART rx and tx
         * interrupts are generated in PIO mode only when configure
         * their peripheral mapping registers properly, which means
         * request corresponding DMA channels in PIO mode as well.
         */
        unsigned uart_dma_ch_rx, uart_dma_ch_tx;

        switch (uart->rx_irq) {
        case IRQ_UART3_RX:
            uart_dma_ch_rx = CH_UART3_RX;
            uart_dma_ch_tx = CH_UART3_TX;
            break;
        case IRQ_UART2_RX:
            uart_dma_ch_rx = CH_UART2_RX;
            uart_dma_ch_tx = CH_UART2_TX;
            break;
        default:
            uart_dma_ch_rx = uart_dma_ch_tx = 0;
            break;
        };

        if (uart_dma_ch_rx &&
            request_dma(uart_dma_ch_rx, "BFIN_UART_RX") < 0) {
            printk(KERN_NOTICE"Fail to attach UART interrupt\n");
            free_irq(uart->rx_irq, uart);
            free_irq(uart->tx_irq, uart);
            return -EBUSY;
        }
        if (uart_dma_ch_tx &&
            request_dma(uart_dma_ch_tx, "BFIN_UART_TX") < 0) {
            printk(KERN_NOTICE "Fail to attach UART interrupt\n");
            free_dma(uart_dma_ch_rx);
            free_irq(uart->rx_irq, uart);
            free_irq(uart->tx_irq, uart);
            return -EBUSY;
        }
    }
# endif
# if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
    defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
    }
# endif
#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS
    if (uart->cts_pin >= 0) {
        if (request_irq(gpio_to_irq(uart->cts_pin),
            bfin_serial_mctrl_cts_int,
            IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
            0, "BFIN_UART_CTS", uart)) {
            uart->cts_pin = -1;
            pr_info("Unable to attach BlackFin UART CTS interrupt. So, disable it.\n");
        }
    }
    if (uart->rts_pin >= 0) {
        if (gpio_request(uart->rts_pin, DRIVER_NAME)) {
            pr_info("fail to request RTS PIN at GPIO_%d\n", uart->rts_pin);
            uart->rts_pin = -1;
        } else
            gpio_direction_output(uart->rts_pin, 0);
    }
#endif
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
    if (uart->cts_pin >= 0) {
        if (request_irq(uart->status_irq, bfin_serial_mctrl_cts_int,
            IRQF_DISABLED, "BFIN_UART_MODEM_STATUS", uart)) {
            uart->cts_pin = -1;
            dev_info(port->dev, "Unable to attach BlackFin UART Modem Status interrupt.\n");
        }

        /* CTS RTS PINs are negative assertive. */
        UART_PUT_MCR(uart, UART_GET_MCR(uart) | ACTS);
        UART_SET_IER(uart, EDSSI);
    }
#endif

    UART_SET_IER(uart, ERBFI);
    return 0;
}

static void bfin_serial_shutdown(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

#ifdef CONFIG_SERIAL_BFIN_DMA
    disable_dma(uart->tx_dma_channel);
    free_dma(uart->tx_dma_channel);
    disable_dma(uart->rx_dma_channel);
    free_dma(uart->rx_dma_channel);
    del_timer(&(uart->rx_dma_timer));
    dma_free_coherent(NULL, PAGE_SIZE, uart->rx_dma_buf.buf, 0);
#else
#ifdef CONFIG_BF54x
    switch (uart->port.irq) {
    case IRQ_UART3_RX:
        free_dma(CH_UART3_RX);
        free_dma(CH_UART3_TX);
        break;
    case IRQ_UART2_RX:
        free_dma(CH_UART2_RX);
        free_dma(CH_UART2_TX);
        break;
    default:
        break;
    };
#endif
    free_irq(uart->rx_irq, uart);
    free_irq(uart->tx_irq, uart);
#endif

#ifdef CONFIG_SERIAL_BFIN_CTSRTS
    if (uart->cts_pin >= 0)
        free_irq(gpio_to_irq(uart->cts_pin), uart);
    if (uart->rts_pin >= 0)
        gpio_free(uart->rts_pin);
#endif
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
    if (uart->cts_pin >= 0)
        free_irq(uart->status_irq, uart);
#endif
}

static void
bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
           struct ktermios *old)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    unsigned long flags;
    unsigned int baud, quot;
    unsigned int ier, lcr = 0;

    switch (termios->c_cflag & CSIZE) {
    case CS8:
        lcr = WLS(8);
        break;
    case CS7:
        lcr = WLS(7);
        break;
    case CS6:
        lcr = WLS(6);
        break;
    case CS5:
        lcr = WLS(5);
        break;
    default:
        printk(KERN_ERR "%s: word lengh not supported\n",
            __func__);
    }

    /* Anomaly notes:
     *  05000231 -  STOP bit is always set to 1 whatever the user is set.
     */
    if (termios->c_cflag & CSTOPB) {
        if (ANOMALY_05000231)
            printk(KERN_WARNING "STOP bits other than 1 is not "
                "supported in case of anomaly 05000231.\n");
        else
            lcr |= STB;
    }
    if (termios->c_cflag & PARENB)
        lcr |= PEN;
    if (!(termios->c_cflag & PARODD))
        lcr |= EPS;
    if (termios->c_cflag & CMSPAR)
        lcr |= STP;

    spin_lock_irqsave(&uart->port.lock, flags);

    port->read_status_mask = OE;
    if (termios->c_iflag & INPCK)
        port->read_status_mask |= (FE | PE);
    if (termios->c_iflag & (BRKINT | PARMRK))
        port->read_status_mask |= BI;

    /*
     * Characters to ignore
     */
    port->ignore_status_mask = 0;
    if (termios->c_iflag & IGNPAR)
        port->ignore_status_mask |= FE | PE;
    if (termios->c_iflag & IGNBRK) {
        port->ignore_status_mask |= BI;
        /*
         * If we're ignoring parity and break indicators,
         * ignore overruns too (for real raw support).
         */
        if (termios->c_iflag & IGNPAR)
            port->ignore_status_mask |= OE;
    }

    baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
    quot = uart_get_divisor(port, baud);

    /* If discipline is not IRDA, apply ANOMALY_05000230 */
    if (termios->c_line != N_IRDA)
        quot -= ANOMALY_05000230;

    UART_SET_ANOMALY_THRESHOLD(uart, USEC_PER_SEC / baud * 15);

    /* Disable UART */
    ier = UART_GET_IER(uart);
    UART_PUT_GCTL(uart, UART_GET_GCTL(uart) & ~UCEN);
    UART_DISABLE_INTS(uart);

    /* Set DLAB in LCR to Access CLK */
    UART_SET_DLAB(uart);

    UART_PUT_CLK(uart, quot);
    SSYNC();

    /* Clear DLAB in LCR to Access THR RBR IER */
    UART_CLEAR_DLAB(uart);

    UART_PUT_LCR(uart, (UART_GET_LCR(uart) & ~LCR_MASK) | lcr);

    /* Enable UART */
    UART_ENABLE_INTS(uart, ier);
    UART_PUT_GCTL(uart, UART_GET_GCTL(uart) | UCEN);

    /* Port speed changed, update the per-port timeout. */
    uart_update_timeout(port, termios->c_cflag, baud);

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

static const char *bfin_serial_type(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

    return uart->port.type == PORT_BFIN ? "BFIN-UART" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'.
 */
static void bfin_serial_release_port(struct uart_port *port)
{
}

/*
 * Request the memory region(s) being used by 'port'.
 */
static int bfin_serial_request_port(struct uart_port *port)
{
    return 0;
}

/*
 * Configure/autoconfigure the port.
 */
static void bfin_serial_config_port(struct uart_port *port, int flags)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

    if (flags & UART_CONFIG_TYPE &&
        bfin_serial_request_port(&uart->port) == 0)
        uart->port.type = PORT_BFIN;
}

/*
 * Verify the new serial_struct (for TIOCSSERIAL).
 * The only change we allow are to the flags and type, and
 * even then only between PORT_BFIN and PORT_UNKNOWN
 */
static int
bfin_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
{
    return 0;
}

/*
 * Enable the IrDA function if tty->ldisc.num is N_IRDA.
 * In other cases, disable IrDA function.
 */
static void bfin_serial_set_ldisc(struct uart_port *port, int ld)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    unsigned int val;

    switch (ld) {
    case N_IRDA:
        val = UART_GET_GCTL(uart);
        val |= (UMOD_IRDA | RPOLC);
        UART_PUT_GCTL(uart, val);
        break;
    default:
        val = UART_GET_GCTL(uart);
        val &= ~(UMOD_MASK | RPOLC);
        UART_PUT_GCTL(uart, val);
    }
}

static void bfin_serial_reset_irda(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    unsigned int val;

    val = UART_GET_GCTL(uart);
    val &= ~(UMOD_MASK | RPOLC);
    UART_PUT_GCTL(uart, val);
    SSYNC();
    val |= (UMOD_IRDA | RPOLC);
    UART_PUT_GCTL(uart, val);
    SSYNC();
}

#ifdef CONFIG_CONSOLE_POLL
/* Anomaly notes:
 *  05000099 -  Because we only use THRE in poll_put and DR in poll_get,
 *      losing other bits of UART_LSR is not a problem here.
 */
static void bfin_serial_poll_put_char(struct uart_port *port, unsigned char chr)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

    while (!(UART_GET_LSR(uart) & THRE))
        cpu_relax();

    UART_CLEAR_DLAB(uart);
    UART_PUT_CHAR(uart, (unsigned char)chr);
}

static int bfin_serial_poll_get_char(struct uart_port *port)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    unsigned char chr;

    while (!(UART_GET_LSR(uart) & DR))
        cpu_relax();

    UART_CLEAR_DLAB(uart);
    chr = UART_GET_CHAR(uart);

    return chr;
}
#endif

#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
    defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
static void bfin_kgdboc_port_shutdown(struct uart_port *port)
{
    if (kgdboc_break_enabled) {
        kgdboc_break_enabled = 0;
        bfin_serial_shutdown(port);
    }
}

static int bfin_kgdboc_port_startup(struct uart_port *port)
{
    kgdboc_port_line = port->line;
    kgdboc_break_enabled = !bfin_serial_startup(port);
    return 0;
}
#endif

static struct uart_ops bfin_serial_pops = {
    .tx_empty   = bfin_serial_tx_empty,
    .set_mctrl  = bfin_serial_set_mctrl,
    .get_mctrl  = bfin_serial_get_mctrl,
    .stop_tx    = bfin_serial_stop_tx,
    .start_tx   = bfin_serial_start_tx,
    .stop_rx    = bfin_serial_stop_rx,
    .enable_ms  = bfin_serial_enable_ms,
    .break_ctl  = bfin_serial_break_ctl,
    .startup    = bfin_serial_startup,
    .shutdown   = bfin_serial_shutdown,
    .set_termios    = bfin_serial_set_termios,
    .set_ldisc  = bfin_serial_set_ldisc,
    .type       = bfin_serial_type,
    .release_port   = bfin_serial_release_port,
    .request_port   = bfin_serial_request_port,
    .config_port    = bfin_serial_config_port,
    .verify_port    = bfin_serial_verify_port,
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
    defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
    .kgdboc_port_startup    = bfin_kgdboc_port_startup,
    .kgdboc_port_shutdown   = bfin_kgdboc_port_shutdown,
#endif
#ifdef CONFIG_CONSOLE_POLL
    .poll_put_char  = bfin_serial_poll_put_char,
    .poll_get_char  = bfin_serial_poll_get_char,
#endif
};

#if defined(CONFIG_SERIAL_BFIN_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
/*
 * If the port was already initialised (eg, by a boot loader),
 * try to determine the current setup.
 */
static void __init
bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
               int *parity, int *bits)
{
    unsigned int status;

    status = UART_GET_IER(uart) & (ERBFI | ETBEI);
    if (status == (ERBFI | ETBEI)) {
        /* ok, the port was enabled */
        u32 lcr, clk;

        lcr = UART_GET_LCR(uart);

        *parity = 'n';
        if (lcr & PEN) {
            if (lcr & EPS)
                *parity = 'e';
            else
                *parity = 'o';
        }
        *bits = ((lcr & WLS_MASK) >> WLS_OFFSET) + 5;

        /* Set DLAB in LCR to Access CLK */
        UART_SET_DLAB(uart);

        clk = UART_GET_CLK(uart);

        /* Clear DLAB in LCR to Access THR RBR IER */
        UART_CLEAR_DLAB(uart);

        *baud = get_sclk() / (16*clk);
    }
    pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __func__, *baud, *parity, *bits);
}

static struct uart_driver bfin_serial_reg;

static void bfin_serial_console_putchar(struct uart_port *port, int ch)
{
    struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
    while (!(UART_GET_LSR(uart) & THRE))
        barrier();
    UART_PUT_CHAR(uart, ch);
}

#endif /* defined (CONFIG_SERIAL_BFIN_CONSOLE) ||
         defined (CONFIG_EARLY_PRINTK) */

#ifdef CONFIG_SERIAL_BFIN_CONSOLE
#define CLASS_BFIN_CONSOLE  "bfin-console"
/*
 * Interrupts are disabled on entering
 */
static void
bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
{
    struct bfin_serial_port *uart = bfin_serial_ports[co->index];
    unsigned long flags;

    spin_lock_irqsave(&uart->port.lock, flags);
    uart_console_write(&uart->port, s, count, bfin_serial_console_putchar);
    spin_unlock_irqrestore(&uart->port.lock, flags);

}

static int __init
bfin_serial_console_setup(struct console *co, char *options)
{
    struct bfin_serial_port *uart;
    int baud = 57600;
    int bits = 8;
    int parity = 'n';
# if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
    defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
    int flow = 'r';
# else
    int flow = 'n';
# endif

    /*
     * 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 < 0 || co->index >= BFIN_UART_NR_PORTS)
        return -ENODEV;

    uart = bfin_serial_ports[co->index];
    if (!uart)
        return -ENODEV;

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

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

static struct console bfin_serial_console = {
    .name       = BFIN_SERIAL_DEV_NAME,
    .write      = bfin_serial_console_write,
    .device     = uart_console_device,
    .setup      = bfin_serial_console_setup,
    .flags      = CON_PRINTBUFFER,
    .index      = -1,
    .data       = &bfin_serial_reg,
};
#define BFIN_SERIAL_CONSOLE (&bfin_serial_console)
#else
#define BFIN_SERIAL_CONSOLE NULL
#endif /* CONFIG_SERIAL_BFIN_CONSOLE */

#ifdef  CONFIG_EARLY_PRINTK
static struct bfin_serial_port bfin_earlyprintk_port;
#define CLASS_BFIN_EARLYPRINTK  "bfin-earlyprintk"

/*
 * Interrupts are disabled on entering
 */
static void
bfin_earlyprintk_console_write(struct console *co, const char *s, unsigned int count)
{
    unsigned long flags;

    if (bfin_earlyprintk_port.port.line != co->index)
        return;

    spin_lock_irqsave(&bfin_earlyprintk_port.port.lock, flags);
    uart_console_write(&bfin_earlyprintk_port.port, s, count,
        bfin_serial_console_putchar);
    spin_unlock_irqrestore(&bfin_earlyprintk_port.port.lock, flags);
}

/*
 * This should have a .setup or .early_setup in it, but then things get called
 * without the command line options, and the baud rate gets messed up - so
 * don't let the common infrastructure play with things. (see calls to setup
 * & earlysetup in ./kernel/printk.c:register_console()
 */
static struct __initdata console bfin_early_serial_console = {
    .name = "early_BFuart",
    .write = bfin_earlyprintk_console_write,
    .device = uart_console_device,
    .flags = CON_PRINTBUFFER,
    .index = -1,
    .data  = &bfin_serial_reg,
};
#endif

static struct uart_driver bfin_serial_reg = {
    .owner          = THIS_MODULE,
    .driver_name        = DRIVER_NAME,
    .dev_name       = BFIN_SERIAL_DEV_NAME,
    .major          = BFIN_SERIAL_MAJOR,
    .minor          = BFIN_SERIAL_MINOR,
    .nr         = BFIN_UART_NR_PORTS,
    .cons           = BFIN_SERIAL_CONSOLE,
};

static int bfin_serial_suspend(struct platform_device *pdev, pm_message_t state)
{
    struct bfin_serial_port *uart = platform_get_drvdata(pdev);

    return uart_suspend_port(&bfin_serial_reg, &uart->port);
}

static int bfin_serial_resume(struct platform_device *pdev)
{
    struct bfin_serial_port *uart = platform_get_drvdata(pdev);

    return uart_resume_port(&bfin_serial_reg, &uart->port);
}

static int bfin_serial_probe(struct platform_device *pdev)
{
    struct resource *res;
    struct bfin_serial_port *uart = NULL;
    int ret = 0;

    if (pdev->id < 0 || pdev->id >= BFIN_UART_NR_PORTS) {
        dev_err(&pdev->dev, "Wrong bfin uart platform device id.\n");
        return -ENOENT;
    }

    if (bfin_serial_ports[pdev->id] == NULL) {

        uart = kzalloc(sizeof(*uart), GFP_KERNEL);
        if (!uart) {
            dev_err(&pdev->dev,
                "fail to malloc bfin_serial_port\n");
            return -ENOMEM;
        }
        bfin_serial_ports[pdev->id] = uart;

#ifdef CONFIG_EARLY_PRINTK
        if (!(bfin_earlyprintk_port.port.membase
            && bfin_earlyprintk_port.port.line == pdev->id)) {
            /*
             * If the peripheral PINs of current port is allocated
             * in earlyprintk probe stage, don't do it again.
             */
#endif
        ret = peripheral_request_list(
            (unsigned short *)pdev->dev.platform_data, DRIVER_NAME);
        if (ret) {
            dev_err(&pdev->dev,
                "fail to request bfin serial peripherals\n");
            goto out_error_free_mem;
        }
#ifdef CONFIG_EARLY_PRINTK
        }
#endif

        spin_lock_init(&uart->port.lock);
        uart->port.uartclk   = get_sclk();
        uart->port.fifosize  = BFIN_UART_TX_FIFO_SIZE;
        uart->port.ops       = &bfin_serial_pops;
        uart->port.line      = pdev->id;
        uart->port.iotype    = UPIO_MEM;
        uart->port.flags     = UPF_BOOT_AUTOCONF;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL) {
            dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
            ret = -ENOENT;
            goto out_error_free_peripherals;
        }

        uart->port.membase = ioremap(res->start, resource_size(res));
        if (!uart->port.membase) {
            dev_err(&pdev->dev, "Cannot map uart IO\n");
            ret = -ENXIO;
            goto out_error_free_peripherals;
        }
        uart->port.mapbase = res->start;

        uart->tx_irq = platform_get_irq(pdev, 0);
        if (uart->tx_irq < 0) {
            dev_err(&pdev->dev, "No uart TX IRQ specified\n");
            ret = -ENOENT;
            goto out_error_unmap;
        }

        uart->rx_irq = platform_get_irq(pdev, 1);
        if (uart->rx_irq < 0) {
            dev_err(&pdev->dev, "No uart RX IRQ specified\n");
            ret = -ENOENT;
            goto out_error_unmap;
        }
        uart->port.irq = uart->rx_irq;

        uart->status_irq = platform_get_irq(pdev, 2);
        if (uart->status_irq < 0) {
            dev_err(&pdev->dev, "No uart status IRQ specified\n");
            ret = -ENOENT;
            goto out_error_unmap;
        }

#ifdef CONFIG_SERIAL_BFIN_DMA
        spin_lock_init(&uart->rx_lock);
        uart->tx_done       = 1;
        uart->tx_count      = 0;

        res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
        if (res == NULL) {
            dev_err(&pdev->dev, "No uart TX DMA channel specified\n");
            ret = -ENOENT;
            goto out_error_unmap;
        }
        uart->tx_dma_channel = res->start;

        res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
        if (res == NULL) {
            dev_err(&pdev->dev, "No uart RX DMA channel specified\n");
            ret = -ENOENT;
            goto out_error_unmap;
        }
        uart->rx_dma_channel = res->start;

        init_timer(&(uart->rx_dma_timer));
#endif

#if defined(CONFIG_SERIAL_BFIN_CTSRTS) || \
    defined(CONFIG_SERIAL_BFIN_HARD_CTSRTS)
        res = platform_get_resource(pdev, IORESOURCE_IO, 0);
        if (res == NULL)
            uart->cts_pin = -1;
        else {
            uart->cts_pin = res->start;
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
            uart->port.flags |= ASYNC_CTS_FLOW;
#endif
        }

        res = platform_get_resource(pdev, IORESOURCE_IO, 1);
        if (res == NULL)
            uart->rts_pin = -1;
        else
            uart->rts_pin = res->start;
#endif
    }

#ifdef CONFIG_SERIAL_BFIN_CONSOLE
    if (!is_early_platform_device(pdev)) {
#endif
        uart = bfin_serial_ports[pdev->id];
        uart->port.dev = &pdev->dev;
        dev_set_drvdata(&pdev->dev, uart);
        ret = uart_add_one_port(&bfin_serial_reg, &uart->port);
#ifdef CONFIG_SERIAL_BFIN_CONSOLE
    }
#endif

    if (!ret)
        return 0;

    if (uart) {
out_error_unmap:
        iounmap(uart->port.membase);
out_error_free_peripherals:
        peripheral_free_list(
            (unsigned short *)pdev->dev.platform_data);
out_error_free_mem:
        kfree(uart);
        bfin_serial_ports[pdev->id] = NULL;
    }

    return ret;
}

static int __devexit bfin_serial_remove(struct platform_device *pdev)
{
    struct bfin_serial_port *uart = platform_get_drvdata(pdev);

    dev_set_drvdata(&pdev->dev, NULL);

    if (uart) {
        uart_remove_one_port(&bfin_serial_reg, &uart->port);
        iounmap(uart->port.membase);
        peripheral_free_list(
            (unsigned short *)pdev->dev.platform_data);
        kfree(uart);
        bfin_serial_ports[pdev->id] = NULL;
    }

    return 0;
}

static struct platform_driver bfin_serial_driver = {
    .probe      = bfin_serial_probe,
    .remove     = __devexit_p(bfin_serial_remove),
    .suspend    = bfin_serial_suspend,
    .resume     = bfin_serial_resume,
    .driver     = {
        .name   = DRIVER_NAME,
        .owner  = THIS_MODULE,
    },
};

#if defined(CONFIG_SERIAL_BFIN_CONSOLE)
static __initdata struct early_platform_driver early_bfin_serial_driver = {
    .class_str = CLASS_BFIN_CONSOLE,
    .pdrv = &bfin_serial_driver,
    .requested_id = EARLY_PLATFORM_ID_UNSET,
};

static int __init bfin_serial_rs_console_init(void)
{
    early_platform_driver_register(&early_bfin_serial_driver, DRIVER_NAME);

    early_platform_driver_probe(CLASS_BFIN_CONSOLE, BFIN_UART_NR_PORTS, 0);

    register_console(&bfin_serial_console);

    return 0;
}
console_initcall(bfin_serial_rs_console_init);
#endif

#ifdef CONFIG_EARLY_PRINTK
/*
 * Memory can't be allocated dynamically during earlyprink init stage.
 * So, do individual probe for earlyprink with a static uart port variable.
 */
static int bfin_earlyprintk_probe(struct platform_device *pdev)
{
    struct resource *res;
    int ret;

    if (pdev->id < 0 || pdev->id >= BFIN_UART_NR_PORTS) {
        dev_err(&pdev->dev, "Wrong earlyprintk platform device id.\n");
        return -ENOENT;
    }

    ret = peripheral_request_list(
        (unsigned short *)pdev->dev.platform_data, DRIVER_NAME);
    if (ret) {
        dev_err(&pdev->dev,
                "fail to request bfin serial peripherals\n");
            return ret;
    }

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (res == NULL) {
        dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
        ret = -ENOENT;
        goto out_error_free_peripherals;
    }

    bfin_earlyprintk_port.port.membase = ioremap(res->start,
                             resource_size(res));
    if (!bfin_earlyprintk_port.port.membase) {
        dev_err(&pdev->dev, "Cannot map uart IO\n");
        ret = -ENXIO;
        goto out_error_free_peripherals;
    }
    bfin_earlyprintk_port.port.mapbase = res->start;
    bfin_earlyprintk_port.port.line = pdev->id;
    bfin_earlyprintk_port.port.uartclk = get_sclk();
    bfin_earlyprintk_port.port.fifosize  = BFIN_UART_TX_FIFO_SIZE;
    spin_lock_init(&bfin_earlyprintk_port.port.lock);

    return 0;

out_error_free_peripherals:
    peripheral_free_list(
        (unsigned short *)pdev->dev.platform_data);

    return ret;
}

static struct platform_driver bfin_earlyprintk_driver = {
    .probe      = bfin_earlyprintk_probe,
    .driver     = {
        .name   = DRIVER_NAME,
        .owner  = THIS_MODULE,
    },
};

static __initdata struct early_platform_driver early_bfin_earlyprintk_driver = {
    .class_str = CLASS_BFIN_EARLYPRINTK,
    .pdrv = &bfin_earlyprintk_driver,
    .requested_id = EARLY_PLATFORM_ID_UNSET,
};

struct console __init *bfin_earlyserial_init(unsigned int port,
                        unsigned int cflag)
{
    struct ktermios t;
    char port_name[20];

    if (port < 0 || port >= BFIN_UART_NR_PORTS)
        return NULL;

    /*
     * Only probe resource of the given port in earlyprintk boot arg.
     * The expected port id should be indicated in port name string.
     */
    snprintf(port_name, 20, DRIVER_NAME ".%d", port);
    early_platform_driver_register(&early_bfin_earlyprintk_driver,
        port_name);
    early_platform_driver_probe(CLASS_BFIN_EARLYPRINTK, 1, 0);

    if (!bfin_earlyprintk_port.port.membase)
        return NULL;

#ifdef CONFIG_SERIAL_BFIN_CONSOLE
    /*
     * If we are using early serial, don't let the normal console rewind
     * log buffer, since that causes things to be printed multiple times
     */
    bfin_serial_console.flags &= ~CON_PRINTBUFFER;
#endif

    bfin_early_serial_console.index = port;
    t.c_cflag = cflag;
    t.c_iflag = 0;
    t.c_oflag = 0;
    t.c_lflag = ICANON;
    t.c_line = port;
    bfin_serial_set_termios(&bfin_earlyprintk_port.port, &t, &t);

    return &bfin_early_serial_console;
}
#endif /* CONFIG_EARLY_PRINTK */

static int __init bfin_serial_init(void)
{
    int ret;

    pr_info("Blackfin serial driver\n");

    ret = uart_register_driver(&bfin_serial_reg);
    if (ret) {
        pr_err("failed to register %s:%d\n",
            bfin_serial_reg.driver_name, ret);
    }

    ret = platform_driver_register(&bfin_serial_driver);
    if (ret) {
        pr_err("fail to register bfin uart\n");
        uart_unregister_driver(&bfin_serial_reg);
    }

    return ret;
}

static void __exit bfin_serial_exit(void)
{
    platform_driver_unregister(&bfin_serial_driver);
    uart_unregister_driver(&bfin_serial_reg);
}


module_init(bfin_serial_init);
module_exit(bfin_serial_exit);

MODULE_AUTHOR("Sonic Zhang, Aubrey Li");
MODULE_DESCRIPTION("Blackfin generic serial port driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(BFIN_SERIAL_MAJOR);
MODULE_ALIAS("platform:bfin-uart");