/*
 * 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

/* 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);
}

#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)
{
        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)
                return;
#endif
        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(&uart->port.state->port);
}

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)
{
        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(&uart->port.state->port);
}

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

        spin_lock_irqsave(&uart->rx_lock, flags);

        /* 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_irqrestore(&uart->rx_lock, flags);

        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,
                        0, "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;
        unsigned long timeout;

#ifdef CONFIG_SERIAL_BFIN_CTSRTS
        if (old == NULL && uart->cts_pin != -1)
                termios->c_cflag |= CRTSCTS;
        else if (uart->cts_pin == -1)
                termios->c_cflag &= ~CRTSCTS;
#endif

        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 length 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 & (IGNBRK | 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);

        /* Wait till the transfer buffer is empty */
        timeout = jiffies + msecs_to_jiffies(10);
        while (UART_GET_GCTL(uart) & UCEN && !(UART_GET_LSR(uart) & TEMT))
                if (time_after(jiffies, timeout)) {
                        dev_warn(port->dev, "timeout waiting for TX buffer empty\n");
                        break;
                }

        /* 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

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,
        .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,
#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 console bfin_early_serial_console __initdata = {
        .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(
                        dev_get_platdata(&pdev->dev),
                        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;

                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(dev_get_platdata(&pdev->dev));
out_error_free_mem:
                kfree(uart);
                bfin_serial_ports[pdev->id] = NULL;
        }

        return ret;
}

static int 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(dev_get_platdata(&pdev->dev));
                kfree(uart);
                bfin_serial_ports[pdev->id] = NULL;
        }

        return 0;
}

static struct platform_driver bfin_serial_driver = {
        .probe          = bfin_serial_probe,
        .remove         = 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 struct early_platform_driver early_bfin_serial_driver __initdata = {
        .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(dev_get_platdata(&pdev->dev),
                                        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(dev_get_platdata(&pdev->dev));

        return ret;
}

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

static struct early_platform_driver early_bfin_earlyprintk_driver __initdata = {
        .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");