blackfin: serial driver

This patch implements the driver necessary use the Analog Devices Blackfin
processor's Serial Port.

Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1012 insertions, 0 deletions

diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
new file mode 100644
index 000000000000..408390f93db9
--- /dev/null
+++ b/drivers/serial/bfin_5xx.c
@@ -0,0 +1,1012 @@
+/*
+ * File:         drivers/serial/bfin_5xx.c
+ * Based on:     Based on drivers/serial/sa1100.c
+ * Author:       Aubrey Li <aubrey.li@analog.com>
+ *
+ * Created:
+ * Description:  Driver for blackfin 5xx serial ports
+ *
+ * Rev:          $Id: bfin_5xx.c,v 1.19 2006/09/24 02:33:53 aubrey Exp $
+ *
+ * Modified:
+ *               Copyright 2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+
+#include <asm/gpio.h>
+#include <asm/mach/bfin_serial_5xx.h>
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+#include <linux/dma-mapping.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/cacheflush.h>
+#endif
+
+/* UART name and device definitions */
+#define BFIN_SERIAL_NAME        "ttyBF"
+#define BFIN_SERIAL_MAJOR       204
+#define BFIN_SERIAL_MINOR       64
+
+/*
+ * 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    5
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
+#else
+static void bfin_serial_do_work(struct work_struct *work);
+static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
+static void local_put_char(struct bfin_serial_port *uart, char ch);
+#endif
+
+static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
+
+/*
+ * 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
+        disable_dma(uart->tx_dma_channel);
+#else
+        unsigned short ier;
+
+        ier = UART_GET_IER(uart);
+        ier &= ~ETBEI;
+        UART_PUT_IER(uart, ier);
+#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;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+        bfin_serial_dma_tx_chars(uart);
+#else
+        unsigned short ier;
+        ier = UART_GET_IER(uart);
+        ier |= ETBEI;
+        UART_PUT_IER(uart, ier);
+        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;
+        unsigned short ier;
+
+        ier = UART_GET_IER(uart);
+        ier &= ~ERBFI;
+        UART_PUT_IER(uart, ier);
+}
+
+/*
+ * Set the modem control timer to fire immediately.
+ */
+static void bfin_serial_enable_ms(struct uart_port *port)
+{
+}
+
+#ifdef CONFIG_SERIAL_BFIN_PIO
+static void local_put_char(struct bfin_serial_port *uart, char ch)
+{
+        unsigned short status;
+        int flags = 0;
+
+        spin_lock_irqsave(&uart->port.lock, flags);
+
+        do {
+                status = UART_GET_LSR(uart);
+        } while (!(status & THRE));
+
+        UART_PUT_CHAR(uart, ch);
+        SSYNC();
+
+        spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
+{
+        struct tty_struct *tty = uart->port.info?uart->port.info->tty:0;
+        unsigned int status, ch, flg;
+#ifdef BF533_FAMILY
+        static int in_break = 0;
+#endif
+
+        status = UART_GET_LSR(uart);
+        ch = UART_GET_CHAR(uart);
+        uart->port.icount.rx++;
+
+#ifdef BF533_FAMILY
+        /* The BF533 family of processors have a nice misbehavior where
+         * they continuously generate characters for a "single" break.
+         * We have to basically ignore this flood until the "next" valid
+         * character comes across.  All other Blackfin families operate
+         * properly though.
+         */
+        if (in_break) {
+                if (ch != 0) {
+                        in_break = 0;
+                        ch = UART_GET_CHAR(uart);
+                }
+                return;
+        }
+#endif
+
+        if (status & BI) {
+#ifdef BF533_FAMILY
+                in_break = 1;
+#endif
+                uart->port.icount.brk++;
+                if (uart_handle_break(&uart->port))
+                        goto ignore_char;
+                flg = TTY_BREAK;
+        } else if (status & PE) {
+                flg = TTY_PARITY;
+                uart->port.icount.parity++;
+        } else if (status & OE) {
+                flg = TTY_OVERRUN;
+                uart->port.icount.overrun++;
+        } else if (status & FE) {
+                flg = TTY_FRAME;
+                uart->port.icount.frame++;
+        } else
+                flg = TTY_NORMAL;
+
+        if (uart_handle_sysrq_char(&uart->port, ch))
+                goto ignore_char;
+        if (tty)
+                uart_insert_char(&uart->port, status, 2, ch, flg);
+
+ignore_char:
+        if (tty)
+                tty_flip_buffer_push(tty);
+}
+
+static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
+{
+        struct circ_buf *xmit = &uart->port.info->xmit;
+
+        if (uart->port.x_char) {
+                UART_PUT_CHAR(uart, uart->port.x_char);
+                uart->port.icount.tx++;
+                uart->port.x_char = 0;
+                return;
+        }
+        /*
+         * Check the modem control lines before
+         * transmitting anything.
+         */
+        bfin_serial_mctrl_check(uart);
+
+        if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+                bfin_serial_stop_tx(&uart->port);
+                return;
+        }
+
+        local_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);
+
+        if (uart_circ_empty(xmit))
+                bfin_serial_stop_tx(&uart->port);
+}
+
+static irqreturn_t bfin_serial_int(int irq, void *dev_id)
+{
+        struct bfin_serial_port *uart = dev_id;
+        unsigned short status;
+
+        spin_lock(&uart->port.lock);
+        status = UART_GET_IIR(uart);
+        do {
+                if ((status & IIR_STATUS) == IIR_TX_READY)
+                        bfin_serial_tx_chars(uart);
+                if ((status & IIR_STATUS) == IIR_RX_READY)
+                        bfin_serial_rx_chars(uart);
+                status = UART_GET_IIR(uart);
+        } while (status & (IIR_TX_READY | IIR_RX_READY));
+        spin_unlock(&uart->port.lock);
+        return IRQ_HANDLED;
+}
+
+static void bfin_serial_do_work(struct work_struct *work)
+{
+        struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
+
+        bfin_serial_mctrl_check(uart);
+}
+
+#endif
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
+{
+        struct circ_buf *xmit = &uart->port.info->xmit;
+        unsigned short ier;
+        int flags = 0;
+
+        if (!uart->tx_done)
+                return;
+
+        uart->tx_done = 0;
+
+        if (uart->port.x_char) {
+                UART_PUT_CHAR(uart, uart->port.x_char);
+                uart->port.icount.tx++;
+                uart->port.x_char = 0;
+                uart->tx_done = 1;
+                return;
+        }
+        /*
+         * Check the modem control lines before
+         * transmitting anything.
+         */
+        bfin_serial_mctrl_check(uart);
+
+        if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+                bfin_serial_stop_tx(&uart->port);
+                uart->tx_done = 1;
+                return;
+        }
+
+        spin_lock_irqsave(&uart->port.lock, flags);
+        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));
+        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);
+        enable_dma(uart->tx_dma_channel);
+        ier = UART_GET_IER(uart);
+        ier |= ETBEI;
+        UART_PUT_IER(uart, ier);
+        spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static void bfin_serial_dma_rx_chars(struct bfin_serial_port * uart)
+{
+        struct tty_struct *tty = uart->port.info->tty;
+        int i, flg, status;
+
+        status = UART_GET_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;
+                flg = TTY_BREAK;
+        } else if (status & PE) {
+                flg = TTY_PARITY;
+                uart->port.icount.parity++;
+        } else if (status & OE) {
+                flg = TTY_OVERRUN;
+                uart->port.icount.overrun++;
+        } else if (status & FE) {
+                flg = TTY_FRAME;
+                uart->port.icount.frame++;
+        } else
+                flg = TTY_NORMAL;
+
+        for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
+                if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
+                        goto dma_ignore_char;
+                uart_insert_char(&uart->port, status, 2, 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;
+        int flags = 0;
+
+        bfin_serial_dma_tx_chars(uart);
+
+        spin_lock_irqsave(&uart->port.lock, flags);
+        x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);
+        if (x_pos == DMA_RX_XCOUNT)
+                x_pos = 0;
+
+        pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
+
+        if (pos>uart->rx_dma_buf.tail) {
+                uart->rx_dma_buf.tail = pos;
+                bfin_serial_dma_rx_chars(uart);
+                uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
+        }
+        spin_unlock_irqrestore(&uart->port.lock, flags);
+        uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
+        add_timer(&(uart->rx_dma_timer));
+}
+
+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.info->xmit;
+        unsigned short ier;
+
+        spin_lock(&uart->port.lock);
+        if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
+                clear_dma_irqstat(uart->tx_dma_channel);
+                disable_dma(uart->tx_dma_channel);
+                ier = UART_GET_IER(uart);
+                ier &= ~ETBEI;
+                UART_PUT_IER(uart, ier);
+                xmit->tail = (xmit->tail+uart->tx_count) &(UART_XMIT_SIZE -1);
+                uart->port.icount.tx+=uart->tx_count;
+
+                if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+                        uart_write_wakeup(&uart->port);
+
+                if (uart_circ_empty(xmit))
+                        bfin_serial_stop_tx(&uart->port);
+                uart->tx_done = 1;
+        }
+
+        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 short irqstat;
+
+        uart->rx_dma_nrows++;
+        if (uart->rx_dma_nrows == DMA_RX_YCOUNT) {
+                uart->rx_dma_nrows = 0;
+                uart->rx_dma_buf.tail = DMA_RX_XCOUNT*DMA_RX_YCOUNT;
+                bfin_serial_dma_rx_chars(uart);
+                uart->rx_dma_buf.head = uart->rx_dma_buf.tail = 0;
+        }
+        spin_lock(&uart->port.lock);
+        irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
+        clear_dma_irqstat(uart->rx_dma_channel);
+
+        spin_unlock(&uart->port.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 short lsr;
+
+        lsr = UART_GET_LSR(uart);
+        if (lsr & TEMT)
+                return TIOCSER_TEMT;
+        else
+                return 0;
+}
+
+static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+        struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+        if (uart->cts_pin < 0)
+                return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+        if (gpio_get_value(uart->cts_pin))
+                return TIOCM_DSR | TIOCM_CAR;
+        else
+#endif
+                return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+        struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+        if (uart->rts_pin < 0)
+                return;
+
+        if (mctrl & TIOCM_RTS)
+                gpio_set_value(uart->rts_pin, 0);
+        else
+                gpio_set_value(uart->rts_pin, 1);
+#endif
+}
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+        unsigned int status;
+# ifdef CONFIG_SERIAL_BFIN_DMA
+        struct uart_info *info = uart->port.info;
+        struct tty_struct *tty = info->tty;
+
+        status = bfin_serial_get_mctrl(&uart->port);
+        if (!(status & TIOCM_CTS)) {
+                tty->hw_stopped = 1;
+        } else {
+                tty->hw_stopped = 0;
+        }
+# else
+        status = bfin_serial_get_mctrl(&uart->port);
+        uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
+        if (!(status & TIOCM_CTS))
+                schedule_work(&uart->cts_workqueue);
+# endif
+#endif
+}
+
+/*
+ * Interrupts are always disabled.
+ */
+static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+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));
+        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 (request_irq
+            (uart->port.irq, bfin_serial_int, IRQF_DISABLED,
+             "BFIN_UART_RX", uart)) {
+                printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
+                return -EBUSY;
+        }
+
+        if (request_irq
+            (uart->port.irq+1, bfin_serial_int, IRQF_DISABLED,
+             "BFIN_UART_TX", uart)) {
+                printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
+                free_irq(uart->port.irq, uart);
+                return -EBUSY;
+        }
+#endif
+        UART_PUT_IER(uart, UART_GET_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));
+#else
+        free_irq(uart->port.irq, uart);
+        free_irq(uart->port.irq+1, 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 short val, ier, lsr, 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",
+                        __FUNCTION__);
+        }
+
+        if (termios->c_cflag & CSTOPB)
+                lcr |= STB;
+        if (termios->c_cflag & PARENB) {
+                lcr |= PEN;
+                if (!(termios->c_cflag & PARODD))
+                        lcr |= EPS;
+        }
+
+        /* These controls are not implemented for this port */
+        termios->c_iflag |= INPCK | BRKINT | PARMRK;
+        termios->c_iflag &= ~(IGNPAR | IGNBRK);
+
+        /* These controls are not implemented for this port */
+        termios->c_iflag |= INPCK | BRKINT | PARMRK;
+        termios->c_iflag &= ~(IGNPAR | IGNBRK);
+
+        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+        quot = uart_get_divisor(port, baud);
+        spin_lock_irqsave(&uart->port.lock, flags);
+
+        do {
+                lsr = UART_GET_LSR(uart);
+        } while (!(lsr & TEMT));
+
+        /* Disable UART */
+        ier = UART_GET_IER(uart);
+        UART_PUT_IER(uart, 0);
+
+        /* Set DLAB in LCR to Access DLL and DLH */
+        val = UART_GET_LCR(uart);
+        val |= DLAB;
+        UART_PUT_LCR(uart, val);
+        SSYNC();
+
+        UART_PUT_DLL(uart, quot & 0xFF);
+        SSYNC();
+        UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
+        SSYNC();
+
+        /* Clear DLAB in LCR to Access THR RBR IER */
+        val = UART_GET_LCR(uart);
+        val &= ~DLAB;
+        UART_PUT_LCR(uart, val);
+        SSYNC();
+
+        UART_PUT_LCR(uart, lcr);
+
+        /* Enable UART */
+        UART_PUT_IER(uart, ier);
+
+        val = UART_GET_GCTL(uart);
+        val |= UCEN;
+        UART_PUT_GCTL(uart, val);
+
+        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;
+}
+
+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,
+        .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,
+};
+
+static void __init bfin_serial_init_ports(void)
+{
+        static int first = 1;
+        int i;
+
+        if (!first)
+                return;
+        first = 0;
+
+        for (i = 0; i < nr_ports; i++) {
+                bfin_serial_ports[i].port.uartclk   = get_sclk();
+                bfin_serial_ports[i].port.ops       = &bfin_serial_pops;
+                bfin_serial_ports[i].port.line      = i;
+                bfin_serial_ports[i].port.iotype    = UPIO_MEM;
+                bfin_serial_ports[i].port.membase   =
+                        (void __iomem *)bfin_serial_resource[i].uart_base_addr;
+                bfin_serial_ports[i].port.mapbase   =
+                        bfin_serial_resource[i].uart_base_addr;
+                bfin_serial_ports[i].port.irq       =
+                        bfin_serial_resource[i].uart_irq;
+                bfin_serial_ports[i].port.flags     = UPF_BOOT_AUTOCONF;
+#ifdef CONFIG_SERIAL_BFIN_DMA
+                bfin_serial_ports[i].tx_done        = 1;
+                bfin_serial_ports[i].tx_count       = 0;
+                bfin_serial_ports[i].tx_dma_channel =
+                        bfin_serial_resource[i].uart_tx_dma_channel;
+                bfin_serial_ports[i].rx_dma_channel =
+                        bfin_serial_resource[i].uart_rx_dma_channel;
+                init_timer(&(bfin_serial_ports[i].rx_dma_timer));
+#else
+                INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
+#endif
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+                bfin_serial_ports[i].cts_pin        =
+                        bfin_serial_resource[i].uart_cts_pin;
+                bfin_serial_ports[i].rts_pin        =
+                        bfin_serial_resource[i].uart_rts_pin;
+#endif
+                bfin_serial_hw_init(&bfin_serial_ports[i]);
+
+        }
+}
+
+#ifdef CONFIG_SERIAL_BFIN_CONSOLE
+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)))
+                barrier();
+        UART_PUT_CHAR(uart, ch);
+        SSYNC();
+}
+
+/*
+ * 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];
+        int flags = 0;
+
+        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);
+
+}
+
+/*
+ * 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 short status;
+
+        status = UART_GET_IER(uart) & (ERBFI | ETBEI);
+        if (status == (ERBFI | ETBEI)) {
+                /* ok, the port was enabled */
+                unsigned short lcr, val;
+                unsigned short dlh, dll;
+
+                lcr = UART_GET_LCR(uart);
+
+                *parity = 'n';
+                if (lcr & PEN) {
+                        if (lcr & EPS)
+                                *parity = 'e';
+                        else
+                                *parity = 'o';
+                }
+                switch (lcr & 0x03) {
+                        case 0: *bits = 5; break;
+                        case 1: *bits = 6; break;
+                        case 2: *bits = 7; break;
+                        case 3: *bits = 8; break;
+                }
+                /* Set DLAB in LCR to Access DLL and DLH */
+                val = UART_GET_LCR(uart);
+                val |= DLAB;
+                UART_PUT_LCR(uart, val);
+
+                dll = UART_GET_DLL(uart);
+                dlh = UART_GET_DLH(uart);
+
+                /* Clear DLAB in LCR to Access THR RBR IER */
+                val = UART_GET_LCR(uart);
+                val &= ~DLAB;
+                UART_PUT_LCR(uart, val);
+
+                *baud = get_sclk() / (16*(dll | dlh << 8));
+        }
+        pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __FUNCTION__, *baud, *parity, *bits);
+}
+
+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';
+#ifdef CONFIG_SERIAL_BFIN_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 == -1 || co->index >= nr_ports)
+                co->index = 0;
+        uart = &bfin_serial_ports[co->index];
+
+        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 uart_driver bfin_serial_reg;
+static struct console bfin_serial_console = {
+        .name           = BFIN_SERIAL_NAME,
+        .write          = bfin_serial_console_write,
+        .device         = uart_console_device,
+        .setup          = bfin_serial_console_setup,
+        .flags          = CON_PRINTBUFFER,
+        .index          = -1,
+        .data           = &bfin_serial_reg,
+};
+
+static int __init bfin_serial_rs_console_init(void)
+{
+        bfin_serial_init_ports();
+        register_console(&bfin_serial_console);
+        return 0;
+}
+console_initcall(bfin_serial_rs_console_init);
+
+#define BFIN_SERIAL_CONSOLE     &bfin_serial_console
+#else
+#define BFIN_SERIAL_CONSOLE     NULL
+#endif
+
+static struct uart_driver bfin_serial_reg = {
+        .owner                  = THIS_MODULE,
+        .driver_name            = "bfin-uart",
+        .dev_name               = BFIN_SERIAL_NAME,
+        .major                  = BFIN_SERIAL_MAJOR,
+        .minor                  = BFIN_SERIAL_MINOR,
+        .nr                     = NR_PORTS,
+        .cons                   = BFIN_SERIAL_CONSOLE,
+};
+
+static int bfin_serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+        struct bfin_serial_port *uart = platform_get_drvdata(dev);
+
+        if (uart)
+                uart_suspend_port(&bfin_serial_reg, &uart->port);
+
+        return 0;
+}
+
+static int bfin_serial_resume(struct platform_device *dev)
+{
+        struct bfin_serial_port *uart = platform_get_drvdata(dev);
+
+        if (uart)
+                uart_resume_port(&bfin_serial_reg, &uart->port);
+
+        return 0;
+}
+
+static int bfin_serial_probe(struct platform_device *dev)
+{
+        struct resource *res = dev->resource;
+        int i;
+
+        for (i = 0; i < dev->num_resources; i++, res++)
+                if (res->flags & IORESOURCE_MEM)
+                        break;
+
+        if (i < dev->num_resources) {
+                for (i = 0; i < nr_ports; i++, res++) {
+                        if (bfin_serial_ports[i].port.mapbase != res->start)
+                                continue;
+                        bfin_serial_ports[i].port.dev = &dev->dev;
+                        uart_add_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
+                        platform_set_drvdata(dev, &bfin_serial_ports[i]);
+                }
+        }
+
+        return 0;
+}
+
+static int bfin_serial_remove(struct platform_device *pdev)
+{
+        struct bfin_serial_port *uart = platform_get_drvdata(pdev);
+
+
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+        gpio_free(uart->cts_pin);
+        gpio_free(uart->rts_pin);
+#endif
+
+        platform_set_drvdata(pdev, NULL);
+
+        if (uart)
+                uart_remove_one_port(&bfin_serial_reg, &uart->port);
+
+        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   = "bfin-uart",
+        },
+};
+
+static int __init bfin_serial_init(void)
+{
+        int ret;
+
+        pr_info("Serial: Blackfin serial driver\n");
+
+        bfin_serial_init_ports();
+
+        ret = uart_register_driver(&bfin_serial_reg);
+        if (ret == 0) {
+                ret = platform_driver_register(&bfin_serial_driver);
+                if (ret) {
+                        pr_debug("uart register failed\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("Aubrey.Li <aubrey.li@analog.com>");
+MODULE_DESCRIPTION("Blackfin generic serial port driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(BFIN_SERIAL_MAJOR);