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bfin_5xx.c

/*
 * 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
 *
 * 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>

#ifdef CONFIG_KGDB_UART
#include <linux/kgdb.h>
#include <asm/irq_regs.h>
#endif

#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;

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

#ifdef CONFIG_SERIAL_BFIN_DMA
      disable_dma(uart->tx_dma_channel);
#else
#ifdef CONFIG_BF54x
      /* Waiting for Transmission Finished */
      while (!(UART_GET_LSR(uart) & TFI))
            continue;
      /* Clear TFI bit */
      UART_PUT_LSR(uart, TFI);
      UART_CLEAR_IER(uart, ETBEI);
#else
      unsigned short ier;

      ier = UART_GET_IER(uart);
      ier &= ~ETBEI;
      UART_PUT_IER(uart, ier);
#endif
#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
#ifdef CONFIG_BF54x
      UART_SET_IER(uart, ETBEI);
#else
      unsigned short ier;
      ier = UART_GET_IER(uart);
      ier |= ETBEI;
      UART_PUT_IER(uart, ier);
#endif
      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;
#ifdef      CONFIG_KGDB_UART
      if (uart->port.line != CONFIG_KGDB_UART_PORT) {
#endif
#ifdef CONFIG_BF54x
      UART_CLEAR_IER(uart, ERBFI);
#else
      unsigned short ier;

      ier = UART_GET_IER(uart);
      ier &= ~ERBFI;
      UART_PUT_IER(uart, ier);
#endif
#ifdef      CONFIG_KGDB_UART
      }
#endif
}

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

#ifdef CONFIG_KGDB_UART
static int kgdb_entry_state;

void kgdb_put_debug_char(int chr)
{
      struct bfin_serial_port *uart;
      
      if (CONFIG_KGDB_UART_PORT<0 || CONFIG_KGDB_UART_PORT>=NR_PORTS)
            uart = &bfin_serial_ports[0];
      else
            uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
      
      while (!(UART_GET_LSR(uart) & THRE)) {
            SSYNC();
      }

#ifndef CONFIG_BF54x
      UART_PUT_LCR(uart, UART_GET_LCR(uart)&(~DLAB));
      SSYNC();
#endif
      UART_PUT_CHAR(uart, (unsigned char)chr);
      SSYNC();
}

int kgdb_get_debug_char(void)
{
      struct bfin_serial_port *uart;
      unsigned char chr;

      if (CONFIG_KGDB_UART_PORT<0 || CONFIG_KGDB_UART_PORT>=NR_PORTS)
            uart = &bfin_serial_ports[0];
      else
            uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
      
      while(!(UART_GET_LSR(uart) & DR)) {
            SSYNC();
      }
#ifndef CONFIG_BF54x
      UART_PUT_LCR(uart, UART_GET_LCR(uart)&(~DLAB));
      SSYNC();
#endif
      chr = UART_GET_CHAR(uart);
      SSYNC();

      return chr;
}
#endif

#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->tty;
      unsigned int status, ch, flg;
      static int in_break = 0;
#ifdef CONFIG_KGDB_UART
      struct pt_regs *regs = get_irq_regs();
#endif

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

#ifdef CONFIG_KGDB_UART
      if (uart->port.line == CONFIG_KGDB_UART_PORT) {
            if (uart->port.cons->index == CONFIG_KGDB_UART_PORT && ch == 0x1) { /* Ctrl + A */
                  kgdb_breakkey_pressed(regs);
                  return;
            } else if (kgdb_entry_state == 0 && ch == '$') {/* connection from KGDB */
                  kgdb_entry_state = 1;
            } else if (kgdb_entry_state == 1 && ch == 'q') {
                  kgdb_entry_state = 0;
                  kgdb_breakkey_pressed(regs);
                  return;
            } else if (ch == 0x3) {/* Ctrl + C */
                  kgdb_entry_state = 0;
                  kgdb_breakkey_pressed(regs);
                  return;
            } else {
                  kgdb_entry_state = 0;
            }
      }
#endif

      if (ANOMALY_05000230) {
            /* 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.
             * Note: While Anomaly 05000230 does not directly address this,
             *       the changes that went in for it also fixed this issue.
             */
            if (in_break) {
                  if (ch != 0) {
                        in_break = 0;
                        ch = UART_GET_CHAR(uart);
                        if (bfin_revid() < 5)
                              return;
                  } else
                        return;
            }
      }

      if (status & BI) {
            if (ANOMALY_05000230)
                  in_break = 1;
            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.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_rx_int(int irq, void *dev_id)
{
      struct bfin_serial_port *uart = dev_id;

#ifdef CONFIG_BF54x
      unsigned short status;
      spin_lock(&uart->port.lock);
      status = UART_GET_LSR(uart);
      while ((UART_GET_IER(uart) & ERBFI) && (status & DR)) {
            bfin_serial_rx_chars(uart);
            status = UART_GET_LSR(uart);
      }
      spin_unlock(&uart->port.lock);
#else
      spin_lock(&uart->port.lock);
      while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_RX_READY)
            bfin_serial_rx_chars(uart);
      spin_unlock(&uart->port.lock);
#endif
      return IRQ_HANDLED;
}

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

#ifdef CONFIG_BF54x
      unsigned short status;
      spin_lock(&uart->port.lock);
      status = UART_GET_LSR(uart);
      while ((UART_GET_IER(uart) & ETBEI) && (status & THRE)) {
            bfin_serial_tx_chars(uart);
            status = UART_GET_LSR(uart);
      }
      spin_unlock(&uart->port.lock);
#else
      spin_lock(&uart->port.lock);
      while ((UART_GET_IIR(uart) & IIR_STATUS) == IIR_TX_READY)
            bfin_serial_tx_chars(uart);
      spin_unlock(&uart->port.lock);
#endif
      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);
#ifdef CONFIG_BF54x
      UART_SET_IER(uart, ETBEI);
#else
      ier = UART_GET_IER(uart);
      ier |= ETBEI;
      UART_PUT_IER(uart, ier);
#endif
      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;
            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.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, 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;
      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);
#ifdef CONFIG_BF54x
            UART_CLEAR_IER(uart, ETBEI);
#else
            ier = UART_GET_IER(uart);
            ier &= ~ETBEI;
            UART_PUT_IER(uart, ier);
#endif
            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)
{
      struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
      u16 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));
      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_rx_int, IRQF_DISABLED,
           "BFIN_UART_RX", uart)) {
# ifdef     CONFIG_KGDB_UART
            if (uart->port.line != CONFIG_KGDB_UART_PORT) {
# endif
            printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
            return -EBUSY;
# ifdef     CONFIG_KGDB_UART
            }
# endif
      }


      if (request_irq
          (uart->port.irq+1, bfin_serial_tx_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
#ifdef CONFIG_BF54x
      UART_SET_IER(uart, ERBFI);
#else
      UART_PUT_IER(uart, UART_GET_IER(uart) | ERBFI);
#endif
      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
#ifdef      CONFIG_KGDB_UART
      if (uart->port.line != CONFIG_KGDB_UART_PORT)
#endif
      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;
      if (termios->c_cflag & CMSPAR)
            lcr |= STP;

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

      do {
            lsr = UART_GET_LSR(uart);
      } while (!(lsr & TEMT));

      /* Disable UART */
      ier = UART_GET_IER(uart);
#ifdef CONFIG_BF54x
      UART_CLEAR_IER(uart, 0xF);
#else
      UART_PUT_IER(uart, 0);
#endif

#ifndef CONFIG_BF54x
      /* Set DLAB in LCR to Access DLL and DLH */
      val = UART_GET_LCR(uart);
      val |= DLAB;
      UART_PUT_LCR(uart, val);
      SSYNC();
#endif

      UART_PUT_DLL(uart, quot & 0xFF);
      SSYNC();
      UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
      SSYNC();

#ifndef CONFIG_BF54x
      /* Clear DLAB in LCR to Access THR RBR IER */
      val = UART_GET_LCR(uart);
      val &= ~DLAB;
      UART_PUT_LCR(uart, val);
      SSYNC();
#endif

      UART_PUT_LCR(uart, lcr);

      /* Enable UART */
#ifdef CONFIG_BF54x
      UART_SET_IER(uart, ier);
#else
      UART_PUT_IER(uart, ier);
#endif

      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
/*
 * 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;
            }
#ifndef CONFIG_BF54x
            /* Set DLAB in LCR to Access DLL and DLH */
            val = UART_GET_LCR(uart);
            val |= DLAB;
            UART_PUT_LCR(uart, val);
#endif

            dll = UART_GET_DLL(uart);
            dlh = UART_GET_DLH(uart);

#ifndef CONFIG_BF54x
            /* Clear DLAB in LCR to Access THR RBR IER */
            val = UART_GET_LCR(uart);
            val &= ~DLAB;
            UART_PUT_LCR(uart, val);
#endif

            *baud = get_sclk() / (16*(dll | dlh << 8));
      }
      pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __FUNCTION__, *baud, *parity, *bits);
}
#endif

#if defined(CONFIG_SERIAL_BFIN_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
static struct uart_driver bfin_serial_reg;

static int __init
bfin_serial_console_setup(struct console *co, char *options)
{
      struct bfin_serial_port *uart;
# ifdef CONFIG_SERIAL_BFIN_CONSOLE
      int baud = 57600;
      int bits = 8;
      int parity = 'n';
#  ifdef CONFIG_SERIAL_BFIN_CTSRTS
      int flow = 'r';
#  else
      int flow = 'n';
#  endif
# 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];

# ifdef CONFIG_SERIAL_BFIN_CONSOLE
      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);
# else
      return 0;
# endif
}
#endif /* defined (CONFIG_SERIAL_BFIN_CONSOLE) ||
                         defined (CONFIG_EARLY_PRINTK) */

#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) & THRE))
            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);

}

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);
#ifdef CONFIG_KGDB_UART
      kgdb_entry_state = 0;
      init_kgdb_uart();
#endif
      return 0;
}
console_initcall(bfin_serial_rs_console_init);

#define BFIN_SERIAL_CONSOLE   &bfin_serial_console
#else
#define BFIN_SERIAL_CONSOLE   NULL
#endif /* CONFIG_SERIAL_BFIN_CONSOLE */


#ifdef CONFIG_EARLY_PRINTK
static __init void early_serial_putc(struct uart_port *port, int ch)
{
      unsigned timeout = 0xffff;
      struct bfin_serial_port *uart = (struct bfin_serial_port *)port;

      while ((!(UART_GET_LSR(uart) & THRE)) && --timeout)
            cpu_relax();
      UART_PUT_CHAR(uart, ch);
}

static __init void early_serial_write(struct console *con, const char *s,
                              unsigned int n)
{
      struct bfin_serial_port *uart = &bfin_serial_ports[con->index];
      unsigned int i;

      for (i = 0; i < n; i++, s++) {
            if (*s == '\n')
                  early_serial_putc(&uart->port, '\r');
            early_serial_putc(&uart->port, *s);
      }
}

static struct __init console bfin_early_serial_console = {
      .name = "early_BFuart",
      .write = early_serial_write,
      .device = uart_console_device,
      .flags = CON_PRINTBUFFER,
      .setup = bfin_serial_console_setup,
      .index = -1,
      .data  = &bfin_serial_reg,
};

struct console __init *bfin_earlyserial_init(unsigned int port,
                                    unsigned int cflag)
{
      struct bfin_serial_port *uart;
      struct ktermios t;

      if (port == -1 || port >= nr_ports)
            port = 0;
      bfin_serial_init_ports();
      bfin_early_serial_console.index = port;
      uart = &bfin_serial_ports[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(&uart->port, &t, &t);
      return &bfin_early_serial_console;
}

#endif /* CONFIG_SERIAL_BFIN_CONSOLE */

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;
#ifdef CONFIG_KGDB_UART
      struct bfin_serial_port *uart = &bfin_serial_ports[CONFIG_KGDB_UART_PORT];
      struct ktermios t;
#endif

      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);
            }
      }
#ifdef CONFIG_KGDB_UART
      if (uart->port.cons->index != CONFIG_KGDB_UART_PORT) {
            request_irq(uart->port.irq, bfin_serial_rx_int,
                  IRQF_DISABLED, "BFIN_UART_RX", uart);
            pr_info("Request irq for kgdb uart port\n");
#ifdef CONFIG_BF54x
            UART_SET_IER(uart, ERBFI);
#else
            UART_PUT_IER(uart, UART_GET_IER(uart) | ERBFI);
#endif
            SSYNC();
            t.c_cflag = CS8|B57600;
            t.c_iflag = 0;
            t.c_oflag = 0;
            t.c_lflag = ICANON;
            t.c_line = CONFIG_KGDB_UART_PORT;
            bfin_serial_set_termios(&uart->port, &t, &t);
      }
#endif
      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);

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