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mcfserial.c

/*
 * mcfserial.c -- serial driver for ColdFire internal UARTS.
 *
 * Copyright (C) 1999-2003 Greg Ungerer <gerg@snapgear.com>
 * Copyright (c) 2000-2001 Lineo, Inc. <www.lineo.com> 
 * Copyright (C) 2001-2002 SnapGear Inc. <www.snapgear.com> 
 *
 * Based on code from 68332serial.c which was:
 *
 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1998 TSHG
 * Copyright (c) 1999 Rt-Control Inc. <jeff@uclinux.org>
 *
 * Changes:
 * 08/07/2003    Daniele Bellucci <bellucda@tiscali.it>
 *               some cleanups in mcfrs_write.
 *
 */
 
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/console.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/semaphore.h>
#include <asm/delay.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
#include <asm/mcfuart.h>
#include <asm/nettel.h>
#include <asm/uaccess.h>
#include "mcfserial.h"

struct timer_list mcfrs_timer_struct;

/*
 *    Default console baud rate,  we use this as the default
 *    for all ports so init can just open /dev/console and
 *    keep going.  Perhaps one day the cflag settings for the
 *    console can be used instead.
 */
#if defined(CONFIG_HW_FEITH)
#define     CONSOLE_BAUD_RATE 38400
#define     DEFAULT_CBAUD           B38400
#elif defined(CONFIG_MOD5272) || defined(CONFIG_M5208EVB) || \
      defined(CONFIG_M5329EVB) || defined(CONFIG_GILBARCO)
#define CONSOLE_BAUD_RATE     115200
#define DEFAULT_CBAUD         B115200
#elif defined(CONFIG_ARNEWSH) || defined(CONFIG_FREESCALE) || \
      defined(CONFIG_senTec) || defined(CONFIG_SNEHA) || defined(CONFIG_AVNET)
#define     CONSOLE_BAUD_RATE 19200
#define     DEFAULT_CBAUD           B19200
#endif

#ifndef CONSOLE_BAUD_RATE
#define     CONSOLE_BAUD_RATE 9600
#define     DEFAULT_CBAUD           B9600
#endif

int mcfrs_console_inited = 0;
int mcfrs_console_port = -1;
int mcfrs_console_baud = CONSOLE_BAUD_RATE;
int mcfrs_console_cbaud = DEFAULT_CBAUD;

/*
 *    Driver data structures.
 */
static struct tty_driver *mcfrs_serial_driver;

/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256

/* Debugging...
 */
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW

#if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \
    defined(CONFIG_M520x) || defined(CONFIG_M532x)
#define     IRQBASE     (MCFINT_VECBASE+MCFINT_UART0)
#else
#define     IRQBASE     73
#endif

/*
 *    Configuration table, UARTs to look for at startup.
 */
static struct mcf_serial mcfrs_table[] = {
      {  /* ttyS0 */
            .magic = 0,
            .addr = (volatile unsigned char *) (MCF_MBAR+MCFUART_BASE1),
            .irq = IRQBASE,
            .flags = ASYNC_BOOT_AUTOCONF,
      },
#ifdef MCFUART_BASE2
      {  /* ttyS1 */
            .magic = 0,
            .addr = (volatile unsigned char *) (MCF_MBAR+MCFUART_BASE2),
            .irq = IRQBASE+1,
            .flags = ASYNC_BOOT_AUTOCONF,
      },
#endif
#ifdef MCFUART_BASE3
      {  /* ttyS2 */
            .magic = 0,
            .addr = (volatile unsigned char *) (MCF_MBAR+MCFUART_BASE3),
            .irq = IRQBASE+2,
            .flags = ASYNC_BOOT_AUTOCONF,
      },
#endif
#ifdef MCFUART_BASE4
      {  /* ttyS3 */
            .magic = 0,
            .addr = (volatile unsigned char *) (MCF_MBAR+MCFUART_BASE4),
            .irq = IRQBASE+3,
            .flags = ASYNC_BOOT_AUTOCONF,
      },
#endif
};


#define     NR_PORTS    (sizeof(mcfrs_table) / sizeof(struct mcf_serial))

/*
 * This is used to figure out the divisor speeds and the timeouts.
 */
static int mcfrs_baud_table[] = {
      0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
      9600, 19200, 38400, 57600, 115200, 230400, 460800, 0
};
#define MCFRS_BAUD_TABLE_SIZE \
                  (sizeof(mcfrs_baud_table)/sizeof(mcfrs_baud_table[0]))


#ifdef CONFIG_MAGIC_SYSRQ
/*
 *    Magic system request keys. Used for debugging...
 */
extern int  magic_sysrq_key(int ch);
#endif


/*
 *    Forware declarations...
 */
static void mcfrs_change_speed(struct mcf_serial *info);
static void mcfrs_wait_until_sent(struct tty_struct *tty, int timeout);


static inline int serial_paranoia_check(struct mcf_serial *info,
                              char *name, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
      static const char badmagic[] =
            "MCFRS(warning): bad magic number for serial struct %s in %s\n";
      static const char badinfo[] =
            "MCFRS(warning): null mcf_serial for %s in %s\n";

      if (!info) {
            printk(badinfo, name, routine);
            return 1;
      }
      if (info->magic != SERIAL_MAGIC) {
            printk(badmagic, name, routine);
            return 1;
      }
#endif
      return 0;
}

/*
 *    Sets or clears DTR and RTS on the requested line.
 */
static void mcfrs_setsignals(struct mcf_serial *info, int dtr, int rts)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;
      
#if 0
      printk("%s(%d): mcfrs_setsignals(info=%x,dtr=%d,rts=%d)\n",
            __FILE__, __LINE__, info, dtr, rts);
#endif

      local_irq_save(flags);
      if (dtr >= 0) {
#ifdef MCFPP_DTR0
            if (info->line)
                  mcf_setppdata(MCFPP_DTR1, (dtr ? 0 : MCFPP_DTR1));
            else
                  mcf_setppdata(MCFPP_DTR0, (dtr ? 0 : MCFPP_DTR0));
#endif
      }
      if (rts >= 0) {
            uartp = info->addr;
            if (rts) {
                  info->sigs |= TIOCM_RTS;
                  uartp[MCFUART_UOP1] = MCFUART_UOP_RTS;
            } else {
                  info->sigs &= ~TIOCM_RTS;
                  uartp[MCFUART_UOP0] = MCFUART_UOP_RTS;
            }
      }
      local_irq_restore(flags);
      return;
}

/*
 *    Gets values of serial signals.
 */
static int mcfrs_getsignals(struct mcf_serial *info)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;
      int               sigs;
#if defined(CONFIG_NETtel) && defined(CONFIG_M5307)
      unsigned short          ppdata;
#endif

#if 0
      printk("%s(%d): mcfrs_getsignals(info=%x)\n", __FILE__, __LINE__);
#endif

      local_irq_save(flags);
      uartp = info->addr;
      sigs = (uartp[MCFUART_UIPR] & MCFUART_UIPR_CTS) ? 0 : TIOCM_CTS;
      sigs |= (info->sigs & TIOCM_RTS);

#ifdef MCFPP_DCD0
{
      unsigned int ppdata;
      ppdata = mcf_getppdata();
      if (info->line == 0) {
            sigs |= (ppdata & MCFPP_DCD0) ? 0 : TIOCM_CD;
            sigs |= (ppdata & MCFPP_DTR0) ? 0 : TIOCM_DTR;
      } else if (info->line == 1) {
            sigs |= (ppdata & MCFPP_DCD1) ? 0 : TIOCM_CD;
            sigs |= (ppdata & MCFPP_DTR1) ? 0 : TIOCM_DTR;
      }
}
#endif

      local_irq_restore(flags);
      return(sigs);
}

/*
 * ------------------------------------------------------------
 * mcfrs_stop() and mcfrs_start()
 *
 * This routines are called before setting or resetting tty->stopped.
 * They enable or disable transmitter interrupts, as necessary.
 * ------------------------------------------------------------
 */
static void mcfrs_stop(struct tty_struct *tty)
{
      volatile unsigned char  *uartp;
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      unsigned long           flags;

      if (serial_paranoia_check(info, tty->name, "mcfrs_stop"))
            return;
      
      local_irq_save(flags);
      uartp = info->addr;
      info->imr &= ~MCFUART_UIR_TXREADY;
      uartp[MCFUART_UIMR] = info->imr;
      local_irq_restore(flags);
}

static void mcfrs_start(struct tty_struct *tty)
{
      volatile unsigned char  *uartp;
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      unsigned long           flags;
      
      if (serial_paranoia_check(info, tty->name, "mcfrs_start"))
            return;

      local_irq_save(flags);
      if (info->xmit_cnt && info->xmit_buf) {
            uartp = info->addr;
            info->imr |= MCFUART_UIR_TXREADY;
            uartp[MCFUART_UIMR] = info->imr;
      }
      local_irq_restore(flags);
}

/*
 * ----------------------------------------------------------------------
 *
 * Here starts the interrupt handling routines.  All of the following
 * subroutines are declared as inline and are folded into
 * mcfrs_interrupt().  They were separated out for readability's sake.
 *
 * Note: mcfrs_interrupt() is a "fast" interrupt, which means that it
 * runs with interrupts turned off.  People who may want to modify
 * mcfrs_interrupt() should try to keep the interrupt handler as fast as
 * possible.  After you are done making modifications, it is not a bad
 * idea to do:
 * 
 * gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
 *
 * and look at the resulting assemble code in serial.s.
 *
 *                      - Ted Ts'o (tytso@mit.edu), 7-Mar-93
 * -----------------------------------------------------------------------
 */

static inline void receive_chars(struct mcf_serial *info)
{
      volatile unsigned char  *uartp;
      struct tty_struct *tty = info->tty;
      unsigned char           status, ch, flag;

      if (!tty)
            return;

      uartp = info->addr;

      while ((status = uartp[MCFUART_USR]) & MCFUART_USR_RXREADY) {
            ch = uartp[MCFUART_URB];
            info->stats.rx++;

#ifdef CONFIG_MAGIC_SYSRQ
            if (mcfrs_console_inited && (info->line == mcfrs_console_port)) {
                  if (magic_sysrq_key(ch))
                        continue;
            }
#endif

            flag = TTY_NORMAL;
            if (status & MCFUART_USR_RXERR) {
                  uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETERR;
                  if (status & MCFUART_USR_RXBREAK) {
                        info->stats.rxbreak++;
                        flag = TTY_BREAK;
                  } else if (status & MCFUART_USR_RXPARITY) {
                        info->stats.rxparity++;
                        flag = TTY_PARITY;
                  } else if (status & MCFUART_USR_RXOVERRUN) {
                        info->stats.rxoverrun++;
                        flag = TTY_OVERRUN;
                  } else if (status & MCFUART_USR_RXFRAMING) {
                        info->stats.rxframing++;
                        flag = TTY_FRAME;
                  }
            }
            tty_insert_flip_char(tty, ch, flag);
      }
      tty_schedule_flip(tty);
      return;
}

static inline void transmit_chars(struct mcf_serial *info)
{
      volatile unsigned char  *uartp;

      uartp = info->addr;

      if (info->x_char) {
            /* Send special char - probably flow control */
            uartp[MCFUART_UTB] = info->x_char;
            info->x_char = 0;
            info->stats.tx++;
      }

      if ((info->xmit_cnt <= 0) || info->tty->stopped) {
            info->imr &= ~MCFUART_UIR_TXREADY;
            uartp[MCFUART_UIMR] = info->imr;
            return;
      }

      while (uartp[MCFUART_USR] & MCFUART_USR_TXREADY) {
            uartp[MCFUART_UTB] = info->xmit_buf[info->xmit_tail++];
            info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
            info->stats.tx++;
            if (--info->xmit_cnt <= 0)
                  break;
      }

      if (info->xmit_cnt < WAKEUP_CHARS)
            schedule_work(&info->tqueue);
      return;
}

/*
 * This is the serial driver's generic interrupt routine
 */
irqreturn_t mcfrs_interrupt(int irq, void *dev_id)
{
      struct mcf_serial *info;
      unsigned char           isr;

      info = &mcfrs_table[(irq - IRQBASE)];
      isr = info->addr[MCFUART_UISR] & info->imr;

      if (isr & MCFUART_UIR_RXREADY)
            receive_chars(info);
      if (isr & MCFUART_UIR_TXREADY)
            transmit_chars(info);
      return IRQ_HANDLED;
}

/*
 * -------------------------------------------------------------------
 * Here ends the serial interrupt routines.
 * -------------------------------------------------------------------
 */

static void mcfrs_offintr(struct work_struct *work)
{
      struct mcf_serial *info = container_of(work, struct mcf_serial, tqueue);
      struct tty_struct *tty = info->tty;
      
      if (tty)
            tty_wakeup(tty);
}


/*
 *    Change of state on a DCD line.
 */
void mcfrs_modem_change(struct mcf_serial *info, int dcd)
{
      if (info->count == 0)
            return;

      if (info->flags & ASYNC_CHECK_CD) {
            if (dcd)
                  wake_up_interruptible(&info->open_wait);
            else 
                  schedule_work(&info->tqueue_hangup);
      }
}


#ifdef MCFPP_DCD0

unsigned short    mcfrs_ppstatus;

/*
 * This subroutine is called when the RS_TIMER goes off. It is used
 * to monitor the state of the DCD lines - since they have no edge
 * sensors and interrupt generators.
 */
static void mcfrs_timer(void)
{
      unsigned int      ppstatus, dcdval, i;

      ppstatus = mcf_getppdata() & (MCFPP_DCD0 | MCFPP_DCD1);

      if (ppstatus != mcfrs_ppstatus) {
            for (i = 0; (i < 2); i++) {
                  dcdval = (i ? MCFPP_DCD1 : MCFPP_DCD0);
                  if ((ppstatus & dcdval) != (mcfrs_ppstatus & dcdval)) {
                        mcfrs_modem_change(&mcfrs_table[i],
                              ((ppstatus & dcdval) ? 0 : 1));
                  }
            }
      }
      mcfrs_ppstatus = ppstatus;

      /* Re-arm timer */
      mcfrs_timer_struct.expires = jiffies + HZ/25;
      add_timer(&mcfrs_timer_struct);
}

#endif      /* MCFPP_DCD0 */


/*
 * This routine is called from the scheduler tqueue when the interrupt
 * routine has signalled that a hangup has occurred. The path of
 * hangup processing is:
 *
 *    serial interrupt routine -> (scheduler tqueue) ->
 *    do_serial_hangup() -> tty->hangup() -> mcfrs_hangup()
 * 
 */
static void do_serial_hangup(struct work_struct *work)
{
      struct mcf_serial *info = container_of(work, struct mcf_serial, tqueue_hangup);
      struct tty_struct *tty = info->tty;
      
      if (tty)
            tty_hangup(tty);
}

static int startup(struct mcf_serial * info)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;
      
      if (info->flags & ASYNC_INITIALIZED)
            return 0;

      if (!info->xmit_buf) {
            info->xmit_buf = (unsigned char *) __get_free_page(GFP_KERNEL);
            if (!info->xmit_buf)
                  return -ENOMEM;
      }

      local_irq_save(flags);

#ifdef SERIAL_DEBUG_OPEN
      printk("starting up ttyS%d (irq %d)...\n", info->line, info->irq);
#endif

      /*
       *    Reset UART, get it into known state...
       */
      uartp = info->addr;
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETRX;  /* reset RX */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETTX;  /* reset TX */
      mcfrs_setsignals(info, 1, 1);

      if (info->tty)
            clear_bit(TTY_IO_ERROR, &info->tty->flags);
      info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;

      /*
       * and set the speed of the serial port
       */
      mcfrs_change_speed(info);

      /*
       * Lastly enable the UART transmitter and receiver, and
       * interrupt enables.
       */
      info->imr = MCFUART_UIR_RXREADY;
      uartp[MCFUART_UCR] = MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE;
      uartp[MCFUART_UIMR] = info->imr;

      info->flags |= ASYNC_INITIALIZED;
      local_irq_restore(flags);
      return 0;
}

/*
 * This routine will shutdown a serial port; interrupts are disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void shutdown(struct mcf_serial * info)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;

      if (!(info->flags & ASYNC_INITIALIZED))
            return;

#ifdef SERIAL_DEBUG_OPEN
      printk("Shutting down serial port %d (irq %d)....\n", info->line,
             info->irq);
#endif
      
      local_irq_save(flags);

      uartp = info->addr;
      uartp[MCFUART_UIMR] = 0;  /* mask all interrupts */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETRX;  /* reset RX */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETTX;  /* reset TX */

      if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
            mcfrs_setsignals(info, 0, 0);

      if (info->xmit_buf) {
            free_page((unsigned long) info->xmit_buf);
            info->xmit_buf = 0;
      }

      if (info->tty)
            set_bit(TTY_IO_ERROR, &info->tty->flags);
      
      info->flags &= ~ASYNC_INITIALIZED;
      local_irq_restore(flags);
}


/*
 * This routine is called to set the UART divisor registers to match
 * the specified baud rate for a serial port.
 */
static void mcfrs_change_speed(struct mcf_serial *info)
{
      volatile unsigned char  *uartp;
      unsigned int            baudclk, cflag;
      unsigned long           flags;
      unsigned char           mr1, mr2;
      int               i;
#ifdef      CONFIG_M5272
      unsigned int            fraction;
#endif

      if (!info->tty || !info->tty->termios)
            return;
      cflag = info->tty->termios->c_cflag;
      if (info->addr == 0)
            return;

#if 0
      printk("%s(%d): mcfrs_change_speed()\n", __FILE__, __LINE__);
#endif

      i = cflag & CBAUD;
      if (i & CBAUDEX) {
            i &= ~CBAUDEX;
            if (i < 1 || i > 4)
                  info->tty->termios->c_cflag &= ~CBAUDEX;
            else
                  i += 15;
      }
      if (i == 0) {
            mcfrs_setsignals(info, 0, -1);
            return;
      }

      /* compute the baudrate clock */
#ifdef      CONFIG_M5272
      /*
       * For the MCF5272, also compute the baudrate fraction.
       */
      baudclk = (MCF_BUSCLK / mcfrs_baud_table[i]) / 32;
      fraction = MCF_BUSCLK - (baudclk * 32 * mcfrs_baud_table[i]);
      fraction *= 16;
      fraction /= (32 * mcfrs_baud_table[i]);
#else
      baudclk = ((MCF_BUSCLK / mcfrs_baud_table[i]) + 16) / 32;
#endif

      info->baud = mcfrs_baud_table[i];

      mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
      mr2 = 0;

      switch (cflag & CSIZE) {
      case CS5:   mr1 |= MCFUART_MR1_CS5; break;
      case CS6:   mr1 |= MCFUART_MR1_CS6; break;
      case CS7:   mr1 |= MCFUART_MR1_CS7; break;
      case CS8:
      default:    mr1 |= MCFUART_MR1_CS8; break;
      }

      if (cflag & PARENB) {
            if (cflag & CMSPAR) {
                  if (cflag & PARODD)
                        mr1 |= MCFUART_MR1_PARITYMARK;
                  else
                        mr1 |= MCFUART_MR1_PARITYSPACE;
            } else {
                  if (cflag & PARODD)
                        mr1 |= MCFUART_MR1_PARITYODD;
                  else
                        mr1 |= MCFUART_MR1_PARITYEVEN;
            }
      } else {
            mr1 |= MCFUART_MR1_PARITYNONE;
      }

      if (cflag & CSTOPB)
            mr2 |= MCFUART_MR2_STOP2;
      else
            mr2 |= MCFUART_MR2_STOP1;

      if (cflag & CRTSCTS) {
            mr1 |= MCFUART_MR1_RXRTS;
            mr2 |= MCFUART_MR2_TXCTS;
      }

      if (cflag & CLOCAL)
            info->flags &= ~ASYNC_CHECK_CD;
      else
            info->flags |= ASYNC_CHECK_CD;

      uartp = info->addr;

      local_irq_save(flags);
#if 0
      printk("%s(%d): mr1=%x mr2=%x baudclk=%x\n", __FILE__, __LINE__,
            mr1, mr2, baudclk);
#endif
      /*
        Note: pg 12-16 of MCF5206e User's Manual states that a
        software reset should be performed prior to changing
        UMR1,2, UCSR, UACR, bit 7
      */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETRX;    /* reset RX */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETTX;    /* reset TX */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETMRPTR; /* reset MR pointer */
      uartp[MCFUART_UMR] = mr1;
      uartp[MCFUART_UMR] = mr2;
      uartp[MCFUART_UBG1] = (baudclk & 0xff00) >> 8;  /* set msb byte */
      uartp[MCFUART_UBG2] = (baudclk & 0xff);         /* set lsb byte */
#ifdef      CONFIG_M5272
      uartp[MCFUART_UFPD] = (fraction & 0xf);         /* set fraction */
#endif
      uartp[MCFUART_UCSR] = MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER;
      uartp[MCFUART_UCR] = MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE;
      mcfrs_setsignals(info, 1, -1);
      local_irq_restore(flags);
      return;
}

static void mcfrs_flush_chars(struct tty_struct *tty)
{
      volatile unsigned char  *uartp;
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      unsigned long           flags;

      if (serial_paranoia_check(info, tty->name, "mcfrs_flush_chars"))
            return;

      uartp = (volatile unsigned char *) info->addr;

      /*
       * re-enable receiver interrupt
       */
      local_irq_save(flags);
      if ((!(info->imr & MCFUART_UIR_RXREADY)) &&
          (info->flags & ASYNC_INITIALIZED) ) {
            info->imr |= MCFUART_UIR_RXREADY;
            uartp[MCFUART_UIMR] = info->imr;
      }
      local_irq_restore(flags);

      if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
          !info->xmit_buf)
            return;

      /* Enable transmitter */
      local_irq_save(flags);
      info->imr |= MCFUART_UIR_TXREADY;
      uartp[MCFUART_UIMR] = info->imr;
      local_irq_restore(flags);
}

static int mcfrs_write(struct tty_struct * tty,
                const unsigned char *buf, int count)
{
      volatile unsigned char  *uartp;
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      unsigned long           flags;
      int               c, total = 0;

#if 0
      printk("%s(%d): mcfrs_write(tty=%x,buf=%x,count=%d)\n",
            __FILE__, __LINE__, (int)tty, (int)buf, count);
#endif

      if (serial_paranoia_check(info, tty->name, "mcfrs_write"))
            return 0;

      if (!tty || !info->xmit_buf)
            return 0;
      
      local_save_flags(flags);
      while (1) {
            local_irq_disable();          
            c = min(count, (int) min(((int)SERIAL_XMIT_SIZE) - info->xmit_cnt - 1,
                  ((int)SERIAL_XMIT_SIZE) - info->xmit_head));
            local_irq_restore(flags);

            if (c <= 0)
                  break;

            memcpy(info->xmit_buf + info->xmit_head, buf, c);

            local_irq_disable();
            info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
            info->xmit_cnt += c;
            local_irq_restore(flags);

            buf += c;
            count -= c;
            total += c;
      }

      local_irq_disable();
      uartp = info->addr;
      info->imr |= MCFUART_UIR_TXREADY;
      uartp[MCFUART_UIMR] = info->imr;
      local_irq_restore(flags);

      return total;
}

static int mcfrs_write_room(struct tty_struct *tty)
{
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      int   ret;

      if (serial_paranoia_check(info, tty->name, "mcfrs_write_room"))
            return 0;
      ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
      if (ret < 0)
            ret = 0;
      return ret;
}

static int mcfrs_chars_in_buffer(struct tty_struct *tty)
{
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;

      if (serial_paranoia_check(info, tty->name, "mcfrs_chars_in_buffer"))
            return 0;
      return info->xmit_cnt;
}

static void mcfrs_flush_buffer(struct tty_struct *tty)
{
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      unsigned long           flags;

      if (serial_paranoia_check(info, tty->name, "mcfrs_flush_buffer"))
            return;

      local_irq_save(flags);
      info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
      local_irq_restore(flags);

      tty_wakeup(tty);
}

/*
 * ------------------------------------------------------------
 * mcfrs_throttle()
 * 
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void mcfrs_throttle(struct tty_struct * tty)
{
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
#ifdef SERIAL_DEBUG_THROTTLE
      char  buf[64];
      
      printk("throttle %s: %d....\n", tty_name(tty, buf),
             tty->ldisc.chars_in_buffer(tty));
#endif

      if (serial_paranoia_check(info, tty->name, "mcfrs_throttle"))
            return;
      
      if (I_IXOFF(tty))
            info->x_char = STOP_CHAR(tty);

      /* Turn off RTS line (do this atomic) */
}

static void mcfrs_unthrottle(struct tty_struct * tty)
{
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
#ifdef SERIAL_DEBUG_THROTTLE
      char  buf[64];
      
      printk("unthrottle %s: %d....\n", tty_name(tty, buf),
             tty->ldisc.chars_in_buffer(tty));
#endif

      if (serial_paranoia_check(info, tty->name, "mcfrs_unthrottle"))
            return;
      
      if (I_IXOFF(tty)) {
            if (info->x_char)
                  info->x_char = 0;
            else
                  info->x_char = START_CHAR(tty);
      }

      /* Assert RTS line (do this atomic) */
}

/*
 * ------------------------------------------------------------
 * mcfrs_ioctl() and friends
 * ------------------------------------------------------------
 */

static int get_serial_info(struct mcf_serial * info,
                     struct serial_struct * retinfo)
{
      struct serial_struct tmp;
  
      if (!retinfo)
            return -EFAULT;
      memset(&tmp, 0, sizeof(tmp));
      tmp.type = info->type;
      tmp.line = info->line;
      tmp.port = (unsigned int) info->addr;
      tmp.irq = info->irq;
      tmp.flags = info->flags;
      tmp.baud_base = info->baud_base;
      tmp.close_delay = info->close_delay;
      tmp.closing_wait = info->closing_wait;
      tmp.custom_divisor = info->custom_divisor;
      return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
}

static int set_serial_info(struct mcf_serial * info,
                     struct serial_struct * new_info)
{
      struct serial_struct new_serial;
      struct mcf_serial old_info;
      int   retval = 0;

      if (!new_info)
            return -EFAULT;
      if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
            return -EFAULT;
      old_info = *info;

      if (!capable(CAP_SYS_ADMIN)) {
            if ((new_serial.baud_base != info->baud_base) ||
                (new_serial.type != info->type) ||
                (new_serial.close_delay != info->close_delay) ||
                ((new_serial.flags & ~ASYNC_USR_MASK) !=
                 (info->flags & ~ASYNC_USR_MASK)))
                  return -EPERM;
            info->flags = ((info->flags & ~ASYNC_USR_MASK) |
                         (new_serial.flags & ASYNC_USR_MASK));
            info->custom_divisor = new_serial.custom_divisor;
            goto check_and_exit;
      }

      if (info->count > 1)
            return -EBUSY;

      /*
       * OK, past this point, all the error checking has been done.
       * At this point, we start making changes.....
       */

      info->baud_base = new_serial.baud_base;
      info->flags = ((info->flags & ~ASYNC_FLAGS) |
                  (new_serial.flags & ASYNC_FLAGS));
      info->type = new_serial.type;
      info->close_delay = new_serial.close_delay;
      info->closing_wait = new_serial.closing_wait;

check_and_exit:
      retval = startup(info);
      return retval;
}

/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 *        is emptied.  On bus types like RS485, the transmitter must
 *        release the bus after transmitting. This must be done when
 *        the transmit shift register is empty, not be done when the
 *        transmit holding register is empty.  This functionality
 *        allows an RS485 driver to be written in user space. 
 */
static int get_lsr_info(struct mcf_serial * info, unsigned int *value)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;
      unsigned char           status;

      local_irq_save(flags);
      uartp = info->addr;
      status = (uartp[MCFUART_USR] & MCFUART_USR_TXEMPTY) ? TIOCSER_TEMT : 0;
      local_irq_restore(flags);

      return put_user(status,value);
}

/*
 * This routine sends a break character out the serial port.
 */
static void send_break( struct mcf_serial * info, int duration)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;

      if (!info->addr)
            return;
      set_current_state(TASK_INTERRUPTIBLE);
      uartp = info->addr;

      local_irq_save(flags);
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDBREAKSTART;
      schedule_timeout(duration);
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDBREAKSTOP;
      local_irq_restore(flags);
}

static int mcfrs_tiocmget(struct tty_struct *tty, struct file *file)
{
      struct mcf_serial * info = (struct mcf_serial *)tty->driver_data;

      if (serial_paranoia_check(info, tty->name, "mcfrs_ioctl"))
            return -ENODEV;
      if (tty->flags & (1 << TTY_IO_ERROR))
            return -EIO;

      return mcfrs_getsignals(info);
}

static int mcfrs_tiocmset(struct tty_struct *tty, struct file *file,
                    unsigned int set, unsigned int clear)
{
      struct mcf_serial * info = (struct mcf_serial *)tty->driver_data;
      int rts = -1, dtr = -1;

      if (serial_paranoia_check(info, tty->name, "mcfrs_ioctl"))
            return -ENODEV;
      if (tty->flags & (1 << TTY_IO_ERROR))
            return -EIO;

      if (set & TIOCM_RTS)
            rts = 1;
      if (set & TIOCM_DTR)
            dtr = 1;
      if (clear & TIOCM_RTS)
            rts = 0;
      if (clear & TIOCM_DTR)
            dtr = 0;

      mcfrs_setsignals(info, dtr, rts);

      return 0;
}

static int mcfrs_ioctl(struct tty_struct *tty, struct file * file,
                unsigned int cmd, unsigned long arg)
{
      struct mcf_serial * info = (struct mcf_serial *)tty->driver_data;
      int retval, error;

      if (serial_paranoia_check(info, tty->name, "mcfrs_ioctl"))
            return -ENODEV;

      if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
          (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
          (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
            if (tty->flags & (1 << TTY_IO_ERROR))
                return -EIO;
      }
      
      switch (cmd) {
            case TCSBRK:      /* SVID version: non-zero arg --> no break */
                  retval = tty_check_change(tty);
                  if (retval)
                        return retval;
                  tty_wait_until_sent(tty, 0);
                  if (!arg)
                        send_break(info, HZ/4); /* 1/4 second */
                  return 0;
            case TCSBRKP:     /* support for POSIX tcsendbreak() */
                  retval = tty_check_change(tty);
                  if (retval)
                        return retval;
                  tty_wait_until_sent(tty, 0);
                  send_break(info, arg ? arg*(HZ/10) : HZ/4);
                  return 0;
            case TIOCGSOFTCAR:
                  error = put_user(C_CLOCAL(tty) ? 1 : 0,
                            (unsigned long *) arg);
                  if (error)
                        return error;
                  return 0;
            case TIOCSSOFTCAR:
                  get_user(arg, (unsigned long *) arg);
                  tty->termios->c_cflag =
                        ((tty->termios->c_cflag & ~CLOCAL) |
                         (arg ? CLOCAL : 0));
                  return 0;
            case TIOCGSERIAL:
                  if (access_ok(VERIFY_WRITE, (void *) arg,
                                    sizeof(struct serial_struct)))
                        return get_serial_info(info,
                                     (struct serial_struct *) arg);
                  return -EFAULT;
            case TIOCSSERIAL:
                  return set_serial_info(info,
                                     (struct serial_struct *) arg);
            case TIOCSERGETLSR: /* Get line status register */
                  if (access_ok(VERIFY_WRITE, (void *) arg,
                                    sizeof(unsigned int)))
                        return get_lsr_info(info, (unsigned int *) arg);
                  return -EFAULT;
            case TIOCSERGSTRUCT:
                  error = copy_to_user((struct mcf_serial *) arg,
                            info, sizeof(struct mcf_serial));
                  if (error)
                        return -EFAULT;
                  return 0;
                  
#ifdef TIOCSET422
            case TIOCSET422: {
                  unsigned int val;
                  get_user(val, (unsigned int *) arg);
                  mcf_setpa(MCFPP_PA11, (val ? 0 : MCFPP_PA11));
                  break;
            }
            case TIOCGET422: {
                  unsigned int val;
                  val = (mcf_getpa() & MCFPP_PA11) ? 0 : 1;
                  put_user(val, (unsigned int *) arg);
                  break;
            }
#endif

            default:
                  return -ENOIOCTLCMD;
            }
      return 0;
}

static void mcfrs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;

      if (tty->termios->c_cflag == old_termios->c_cflag)
            return;

      mcfrs_change_speed(info);

      if ((old_termios->c_cflag & CRTSCTS) &&
          !(tty->termios->c_cflag & CRTSCTS)) {
            tty->hw_stopped = 0;
            mcfrs_setsignals(info, -1, 1);
#if 0
            mcfrs_start(tty);
#endif
      }
}

/*
 * ------------------------------------------------------------
 * mcfrs_close()
 * 
 * This routine is called when the serial port gets closed.  First, we
 * wait for the last remaining data to be sent.  Then, we unlink its
 * S structure from the interrupt chain if necessary, and we free
 * that IRQ if nothing is left in the chain.
 * ------------------------------------------------------------
 */
static void mcfrs_close(struct tty_struct *tty, struct file * filp)
{
      volatile unsigned char  *uartp;
      struct mcf_serial *info = (struct mcf_serial *)tty->driver_data;
      unsigned long           flags;

      if (!info || serial_paranoia_check(info, tty->name, "mcfrs_close"))
            return;
      
      local_irq_save(flags);
      
      if (tty_hung_up_p(filp)) {
            local_irq_restore(flags);
            return;
      }
      
#ifdef SERIAL_DEBUG_OPEN
      printk("mcfrs_close ttyS%d, count = %d\n", info->line, info->count);
#endif
      if ((tty->count == 1) && (info->count != 1)) {
            /*
             * Uh, oh.  tty->count is 1, which means that the tty
             * structure will be freed.  Info->count should always
             * be one in these conditions.  If it's greater than
             * one, we've got real problems, since it means the
             * serial port won't be shutdown.
             */
            printk("MCFRS: bad serial port count; tty->count is 1, "
                   "info->count is %d\n", info->count);
            info->count = 1;
      }
      if (--info->count < 0) {
            printk("MCFRS: bad serial port count for ttyS%d: %d\n",
                   info->line, info->count);
            info->count = 0;
      }
      if (info->count) {
            local_irq_restore(flags);
            return;
      }
      info->flags |= ASYNC_CLOSING;

      /*
       * Now we wait for the transmit buffer to clear; and we notify 
       * the line discipline to only process XON/XOFF characters.
       */
      tty->closing = 1;
      if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
            tty_wait_until_sent(tty, info->closing_wait);

      /*
       * At this point we stop accepting input.  To do this, we
       * disable the receive line status interrupts, and tell the
       * interrupt driver to stop checking the data ready bit in the
       * line status register.
       */
      info->imr &= ~MCFUART_UIR_RXREADY;
      uartp = info->addr;
      uartp[MCFUART_UIMR] = info->imr;

#if 0
      /* FIXME: do we need to keep this enabled for console?? */
      if (mcfrs_console_inited && (mcfrs_console_port == info->line)) {
            /* Do not disable the UART */ ;
      } else
#endif
      shutdown(info);
      if (tty->driver->flush_buffer)
            tty->driver->flush_buffer(tty);
      tty_ldisc_flush(tty);
      
      tty->closing = 0;
      info->event = 0;
      info->tty = 0;
#if 0 
      if (tty->ldisc.num != ldiscs[N_TTY].num) {
            if (tty->ldisc.close)
                  (tty->ldisc.close)(tty);
            tty->ldisc = ldiscs[N_TTY];
            tty->termios->c_line = N_TTY;
            if (tty->ldisc.open)
                  (tty->ldisc.open)(tty);
      }
#endif      
      if (info->blocked_open) {
            if (info->close_delay) {
                  msleep_interruptible(jiffies_to_msecs(info->close_delay));
            }
            wake_up_interruptible(&info->open_wait);
      }
      info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
      wake_up_interruptible(&info->close_wait);
      local_irq_restore(flags);
}

/*
 * mcfrs_wait_until_sent() --- wait until the transmitter is empty
 */
static void
mcfrs_wait_until_sent(struct tty_struct *tty, int timeout)
{
#ifdef      CONFIG_M5272
#define     MCF5272_FIFO_SIZE 25          /* fifo size + shift reg */

      struct mcf_serial * info = (struct mcf_serial *)tty->driver_data;
      volatile unsigned char *uartp;
      unsigned long orig_jiffies, fifo_time, char_time, fifo_cnt;

      if (serial_paranoia_check(info, tty->name, "mcfrs_wait_until_sent"))
            return;

      orig_jiffies = jiffies;

      /*
       * Set the check interval to be 1/5 of the approximate time
       * to send the entire fifo, and make it at least 1.  The check
       * interval should also be less than the timeout.
       *
       * Note: we have to use pretty tight timings here to satisfy
       * the NIST-PCTS.
       */
      fifo_time = (MCF5272_FIFO_SIZE * HZ * 10) / info->baud;
      char_time = fifo_time / 5;
      if (char_time == 0)
            char_time = 1;
      if (timeout && timeout < char_time)
            char_time = timeout;

      /*
       * Clamp the timeout period at 2 * the time to empty the
       * fifo.  Just to be safe, set the minimum at .5 seconds.
       */
      fifo_time *= 2;
      if (fifo_time < (HZ/2))
            fifo_time = HZ/2;
      if (!timeout || timeout > fifo_time)
            timeout = fifo_time;

      /*
       * Account for the number of bytes in the UART
       * transmitter FIFO plus any byte being shifted out.
       */
      uartp = (volatile unsigned char *) info->addr;
      for (;;) {
            fifo_cnt = (uartp[MCFUART_UTF] & MCFUART_UTF_TXB);
            if ((uartp[MCFUART_USR] & (MCFUART_USR_TXREADY|
                        MCFUART_USR_TXEMPTY)) ==
                  MCFUART_USR_TXREADY)
                  fifo_cnt++;
            if (fifo_cnt == 0)
                  break;
            msleep_interruptible(jiffies_to_msecs(char_time));
            if (signal_pending(current))
                  break;
            if (timeout && time_after(jiffies, orig_jiffies + timeout))
                  break;
      }
#else
      /*
       * For the other coldfire models, assume all data has been sent
       */
#endif
}

/*
 * mcfrs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
void mcfrs_hangup(struct tty_struct *tty)
{
      struct mcf_serial * info = (struct mcf_serial *)tty->driver_data;
      
      if (serial_paranoia_check(info, tty->name, "mcfrs_hangup"))
            return;
      
      mcfrs_flush_buffer(tty);
      shutdown(info);
      info->event = 0;
      info->count = 0;
      info->flags &= ~ASYNC_NORMAL_ACTIVE;
      info->tty = 0;
      wake_up_interruptible(&info->open_wait);
}

/*
 * ------------------------------------------------------------
 * mcfrs_open() and friends
 * ------------------------------------------------------------
 */
static int block_til_ready(struct tty_struct *tty, struct file * filp,
                     struct mcf_serial *info)
{
      DECLARE_WAITQUEUE(wait, current);
      int   retval;
      int   do_clocal = 0;

      /*
       * If the device is in the middle of being closed, then block
       * until it's done, and then try again.
       */
      if (info->flags & ASYNC_CLOSING) {
            interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
            if (info->flags & ASYNC_HUP_NOTIFY)
                  return -EAGAIN;
            else
                  return -ERESTARTSYS;
#else
            return -EAGAIN;
#endif
      }
      
      /*
       * If non-blocking mode is set, or the port is not enabled,
       * then make the check up front and then exit.
       */
      if ((filp->f_flags & O_NONBLOCK) ||
          (tty->flags & (1 << TTY_IO_ERROR))) {
            info->flags |= ASYNC_NORMAL_ACTIVE;
            return 0;
      }

      if (tty->termios->c_cflag & CLOCAL)
            do_clocal = 1;

      /*
       * Block waiting for the carrier detect and the line to become
       * free (i.e., not in use by the callout).  While we are in
       * this loop, info->count is dropped by one, so that
       * mcfrs_close() knows when to free things.  We restore it upon
       * exit, either normal or abnormal.
       */
      retval = 0;
      add_wait_queue(&info->open_wait, &wait);
#ifdef SERIAL_DEBUG_OPEN
      printk("block_til_ready before block: ttyS%d, count = %d\n",
             info->line, info->count);
#endif
      info->count--;
      info->blocked_open++;
      while (1) {
            local_irq_disable();
            mcfrs_setsignals(info, 1, 1);
            local_irq_enable();
            current->state = TASK_INTERRUPTIBLE;
            if (tty_hung_up_p(filp) ||
                !(info->flags & ASYNC_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
                  if (info->flags & ASYNC_HUP_NOTIFY)
                        retval = -EAGAIN;
                  else
                        retval = -ERESTARTSYS;  
#else
                  retval = -EAGAIN;
#endif
                  break;
            }
            if (!(info->flags & ASYNC_CLOSING) &&
                (do_clocal || (mcfrs_getsignals(info) & TIOCM_CD)))
                  break;
            if (signal_pending(current)) {
                  retval = -ERESTARTSYS;
                  break;
            }
#ifdef SERIAL_DEBUG_OPEN
            printk("block_til_ready blocking: ttyS%d, count = %d\n",
                   info->line, info->count);
#endif
            schedule();
      }
      current->state = TASK_RUNNING;
      remove_wait_queue(&info->open_wait, &wait);
      if (!tty_hung_up_p(filp))
            info->count++;
      info->blocked_open--;
#ifdef SERIAL_DEBUG_OPEN
      printk("block_til_ready after blocking: ttyS%d, count = %d\n",
             info->line, info->count);
#endif
      if (retval)
            return retval;
      info->flags |= ASYNC_NORMAL_ACTIVE;
      return 0;
}     

/*
 * This routine is called whenever a serial port is opened. It
 * enables interrupts for a serial port, linking in its structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
int mcfrs_open(struct tty_struct *tty, struct file * filp)
{
      struct mcf_serial *info;
      int               retval, line;

      line = tty->index;
      if ((line < 0) || (line >= NR_PORTS))
            return -ENODEV;
      info = mcfrs_table + line;
      if (serial_paranoia_check(info, tty->name, "mcfrs_open"))
            return -ENODEV;
#ifdef SERIAL_DEBUG_OPEN
      printk("mcfrs_open %s, count = %d\n", tty->name, info->count);
#endif
      info->count++;
      tty->driver_data = info;
      info->tty = tty;

      /*
       * Start up serial port
       */
      retval = startup(info);
      if (retval)
            return retval;

      retval = block_til_ready(tty, filp, info);
      if (retval) {
#ifdef SERIAL_DEBUG_OPEN
            printk("mcfrs_open returning after block_til_ready with %d\n",
                   retval);
#endif
            return retval;
      }

#ifdef SERIAL_DEBUG_OPEN
      printk("mcfrs_open %s successful...\n", tty->name);
#endif
      return 0;
}

/*
 *    Based on the line number set up the internal interrupt stuff.
 */
static void mcfrs_irqinit(struct mcf_serial *info)
{
#if defined(CONFIG_M5272)
      volatile unsigned long  *icrp;
      volatile unsigned long  *portp;
      volatile unsigned char  *uartp;

      uartp = info->addr;
      icrp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_ICR2);

      switch (info->line) {
      case 0:
            *icrp = 0xe0000000;
            break;
      case 1:
            *icrp = 0x0e000000;
            break;
      default:
            printk("MCFRS: don't know how to handle UART %d interrupt?\n",
                  info->line);
            return;
      }

      /* Enable the output lines for the serial ports */
      portp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_PBCNT);
      *portp = (*portp & ~0x000000ff) | 0x00000055;
      portp = (volatile unsigned long *) (MCF_MBAR + MCFSIM_PDCNT);
      *portp = (*portp & ~0x000003fc) | 0x000002a8;
#elif defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x)
      volatile unsigned char *icrp, *uartp;
      volatile unsigned long *imrp;

      uartp = info->addr;

      icrp = (volatile unsigned char *) (MCF_MBAR + MCFICM_INTC0 +
            MCFINTC_ICR0 + MCFINT_UART0 + info->line);
      *icrp = 0x30 + info->line; /* level 6, line based priority */

      imrp = (volatile unsigned long *) (MCF_MBAR + MCFICM_INTC0 +
            MCFINTC_IMRL);
      *imrp &= ~((1 << (info->irq - MCFINT_VECBASE)) | 1);
#if defined(CONFIG_M527x)
      {
            /*
             * External Pin Mask Setting & Enable External Pin for Interface
             * mrcbis@aliceposta.it
             */
            u16 *serpin_enable_mask;
            serpin_enable_mask = (u16 *) (MCF_IPSBAR + MCF_GPIO_PAR_UART);
            if (info->line == 0)
                  *serpin_enable_mask |= UART0_ENABLE_MASK;
            else if (info->line == 1)
                  *serpin_enable_mask |= UART1_ENABLE_MASK;
            else if (info->line == 2)
                  *serpin_enable_mask |= UART2_ENABLE_MASK;
      }
#endif
#if defined(CONFIG_M528x)
      /* make sure PUAPAR is set for UART0 and UART1 */
      if (info->line < 2) {
            volatile unsigned char *portp = (volatile unsigned char *) (MCF_MBAR + MCF5282_GPIO_PUAPAR);
            *portp |= (0x03 << (info->line * 2));
      }
#endif
#elif defined(CONFIG_M520x)
      volatile unsigned char *icrp, *uartp;
      volatile unsigned long *imrp;

      uartp = info->addr;

      icrp = (volatile unsigned char *) (MCF_MBAR + MCFICM_INTC0 +
            MCFINTC_ICR0 + MCFINT_UART0 + info->line);
      *icrp = 0x03;

      imrp = (volatile unsigned long *) (MCF_MBAR + MCFICM_INTC0 +
            MCFINTC_IMRL);
      *imrp &= ~((1 << (info->irq - MCFINT_VECBASE)) | 1);
      if (info->line < 2) {
            unsigned short *uart_par;
            uart_par = (unsigned short *)(MCF_IPSBAR + MCF_GPIO_PAR_UART);
            if (info->line == 0)
                  *uart_par |=  MCF_GPIO_PAR_UART_PAR_UTXD0
                          | MCF_GPIO_PAR_UART_PAR_URXD0;
            else if (info->line == 1)
                  *uart_par |=  MCF_GPIO_PAR_UART_PAR_UTXD1
                          | MCF_GPIO_PAR_UART_PAR_URXD1;
            } else if (info->line == 2) {
                  unsigned char *feci2c_par;
                  feci2c_par = (unsigned char *)(MCF_IPSBAR +  MCF_GPIO_PAR_FECI2C);
                  *feci2c_par &= ~0x0F;
                  *feci2c_par |=  MCF_GPIO_PAR_FECI2C_PAR_SCL_UTXD2
                            | MCF_GPIO_PAR_FECI2C_PAR_SDA_URXD2;
            }
#elif defined(CONFIG_M532x)
      volatile unsigned char *uartp;
      uartp = info->addr;
      switch (info->line) {
      case 0:
            MCF_INTC0_ICR26 = 0x3;
            MCF_INTC0_CIMR = 26;
            /* GPIO initialization */
            MCF_GPIO_PAR_UART |= 0x000F;
            break;
      case 1:
            MCF_INTC0_ICR27 = 0x3;
            MCF_INTC0_CIMR = 27;
            /* GPIO initialization */
            MCF_GPIO_PAR_UART |= 0x0FF0;
            break;
      case 2:
            MCF_INTC0_ICR28 = 0x3;
            MCF_INTC0_CIMR = 28;
            /* GPIOs also must be initalized, depends on board */
            break;
      }
#else
      volatile unsigned char  *icrp, *uartp;

      switch (info->line) {
      case 0:
            icrp = (volatile unsigned char *) (MCF_MBAR + MCFSIM_UART1ICR);
            *icrp = /*MCFSIM_ICR_AUTOVEC |*/ MCFSIM_ICR_LEVEL6 |
                  MCFSIM_ICR_PRI1;
            mcf_setimr(mcf_getimr() & ~MCFSIM_IMR_UART1);
            break;
      case 1:
            icrp = (volatile unsigned char *) (MCF_MBAR + MCFSIM_UART2ICR);
            *icrp = /*MCFSIM_ICR_AUTOVEC |*/ MCFSIM_ICR_LEVEL6 |
                  MCFSIM_ICR_PRI2;
            mcf_setimr(mcf_getimr() & ~MCFSIM_IMR_UART2);
            break;
      default:
            printk("MCFRS: don't know how to handle UART %d interrupt?\n",
                  info->line);
            return;
      }

      uartp = info->addr;
      uartp[MCFUART_UIVR] = info->irq;
#endif

      /* Clear mask, so no surprise interrupts. */
      uartp[MCFUART_UIMR] = 0;

      if (request_irq(info->irq, mcfrs_interrupt, IRQF_DISABLED,
          "ColdFire UART", NULL)) {
            printk("MCFRS: Unable to attach ColdFire UART %d interrupt "
                  "vector=%d\n", info->line, info->irq);
      }

      return;
}


char *mcfrs_drivername = "ColdFire internal UART serial driver version 1.00\n";


/*
 * Serial stats reporting...
 */
int mcfrs_readproc(char *page, char **start, off_t off, int count,
                     int *eof, void *data)
{
      struct mcf_serial *info;
      char              str[20];
      int               len, sigs, i;

      len = sprintf(page, mcfrs_drivername);
      for (i = 0; (i < NR_PORTS); i++) {
            info = &mcfrs_table[i];
            len += sprintf((page + len), "%d: port:%x irq=%d baud:%d ",
                  i, (unsigned int) info->addr, info->irq, info->baud);
            if (info->stats.rx || info->stats.tx)
                  len += sprintf((page + len), "tx:%d rx:%d ",
                  info->stats.tx, info->stats.rx);
            if (info->stats.rxframing)
                  len += sprintf((page + len), "fe:%d ",
                  info->stats.rxframing);
            if (info->stats.rxparity)
                  len += sprintf((page + len), "pe:%d ",
                  info->stats.rxparity);
            if (info->stats.rxbreak)
                  len += sprintf((page + len), "brk:%d ",
                  info->stats.rxbreak);
            if (info->stats.rxoverrun)
                  len += sprintf((page + len), "oe:%d ",
                  info->stats.rxoverrun);

            str[0] = str[1] = 0;
            if ((sigs = mcfrs_getsignals(info))) {
                  if (sigs & TIOCM_RTS)
                        strcat(str, "|RTS");
                  if (sigs & TIOCM_CTS)
                        strcat(str, "|CTS");
                  if (sigs & TIOCM_DTR)
                        strcat(str, "|DTR");
                  if (sigs & TIOCM_CD)
                        strcat(str, "|CD");
            }

            len += sprintf((page + len), "%s\n", &str[1]);
      }

      return(len);
}


/* Finally, routines used to initialize the serial driver. */

static void show_serial_version(void)
{
      printk(mcfrs_drivername);
}

static const struct tty_operations mcfrs_ops = {
      .open = mcfrs_open,
      .close = mcfrs_close,
      .write = mcfrs_write,
      .flush_chars = mcfrs_flush_chars,
      .write_room = mcfrs_write_room,
      .chars_in_buffer = mcfrs_chars_in_buffer,
      .flush_buffer = mcfrs_flush_buffer,
      .ioctl = mcfrs_ioctl,
      .throttle = mcfrs_throttle,
      .unthrottle = mcfrs_unthrottle,
      .set_termios = mcfrs_set_termios,
      .stop = mcfrs_stop,
      .start = mcfrs_start,
      .hangup = mcfrs_hangup,
      .read_proc = mcfrs_readproc,
      .wait_until_sent = mcfrs_wait_until_sent,
      .tiocmget = mcfrs_tiocmget,
      .tiocmset = mcfrs_tiocmset,
};

/* mcfrs_init inits the driver */
static int __init
mcfrs_init(void)
{
      struct mcf_serial *info;
      unsigned long           flags;
      int               i;

      /* Setup base handler, and timer table. */
#ifdef MCFPP_DCD0
      init_timer(&mcfrs_timer_struct);
      mcfrs_timer_struct.function = mcfrs_timer;
      mcfrs_timer_struct.data = 0;
      mcfrs_timer_struct.expires = jiffies + HZ/25;
      add_timer(&mcfrs_timer_struct);
      mcfrs_ppstatus = mcf_getppdata() & (MCFPP_DCD0 | MCFPP_DCD1);
#endif
      mcfrs_serial_driver = alloc_tty_driver(NR_PORTS);
      if (!mcfrs_serial_driver)
            return -ENOMEM;

      show_serial_version();

      /* Initialize the tty_driver structure */
      mcfrs_serial_driver->owner = THIS_MODULE;
      mcfrs_serial_driver->name = "ttyS";
      mcfrs_serial_driver->driver_name = "mcfserial";
      mcfrs_serial_driver->major = TTY_MAJOR;
      mcfrs_serial_driver->minor_start = 64;
      mcfrs_serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
      mcfrs_serial_driver->subtype = SERIAL_TYPE_NORMAL;
      mcfrs_serial_driver->init_termios = tty_std_termios;

      mcfrs_serial_driver->init_termios.c_cflag =
            mcfrs_console_cbaud | CS8 | CREAD | HUPCL | CLOCAL;
      mcfrs_serial_driver->flags = TTY_DRIVER_REAL_RAW;

      tty_set_operations(mcfrs_serial_driver, &mcfrs_ops);

      if (tty_register_driver(mcfrs_serial_driver)) {
            printk("MCFRS: Couldn't register serial driver\n");
            put_tty_driver(mcfrs_serial_driver);
            return(-EBUSY);
      }

      local_irq_save(flags);

      /*
       *    Configure all the attached serial ports.
       */
      for (i = 0, info = mcfrs_table; (i < NR_PORTS); i++, info++) {
            info->magic = SERIAL_MAGIC;
            info->line = i;
            info->tty = 0;
            info->custom_divisor = 16;
            info->close_delay = 50;
            info->closing_wait = 3000;
            info->x_char = 0;
            info->event = 0;
            info->count = 0;
            info->blocked_open = 0;
            INIT_WORK(&info->tqueue, mcfrs_offintr);
            INIT_WORK(&info->tqueue_hangup, do_serial_hangup);
            init_waitqueue_head(&info->open_wait);
            init_waitqueue_head(&info->close_wait);

            info->imr = 0;
            mcfrs_setsignals(info, 0, 0);
            mcfrs_irqinit(info);

            printk("ttyS%d at 0x%04x (irq = %d)", info->line,
                  (unsigned int) info->addr, info->irq);
            printk(" is a builtin ColdFire UART\n");
      }

      local_irq_restore(flags);
      return 0;
}

module_init(mcfrs_init);

/****************************************************************************/
/*                          Serial Console                                  */
/****************************************************************************/

/*
 *    Quick and dirty UART initialization, for console output.
 */

void mcfrs_init_console(void)
{
      volatile unsigned char  *uartp;
      unsigned int            clk;

      /*
       *    Reset UART, get it into known state...
       */
      uartp = (volatile unsigned char *) (MCF_MBAR +
            (mcfrs_console_port ? MCFUART_BASE2 : MCFUART_BASE1));

      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETRX;  /* reset RX */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETTX;  /* reset TX */
      uartp[MCFUART_UCR] = MCFUART_UCR_CMDRESETMRPTR;  /* reset MR pointer */

      /*
       * Set port for defined baud , 8 data bits, 1 stop bit, no parity.
       */
      uartp[MCFUART_UMR] = MCFUART_MR1_PARITYNONE | MCFUART_MR1_CS8;
      uartp[MCFUART_UMR] = MCFUART_MR2_STOP1;

#ifdef      CONFIG_M5272
{
      /*
       * For the MCF5272, also compute the baudrate fraction.
       */
      int fraction = MCF_BUSCLK - (clk * 32 * mcfrs_console_baud);
      fraction *= 16;
      fraction /= (32 * mcfrs_console_baud);
      uartp[MCFUART_UFPD] = (fraction & 0xf);         /* set fraction */
      clk = (MCF_BUSCLK / mcfrs_console_baud) / 32;
}
#else
      clk = ((MCF_BUSCLK / mcfrs_console_baud) + 16) / 32; /* set baud */
#endif

      uartp[MCFUART_UBG1] = (clk & 0xff00) >> 8;  /* set msb baud */
      uartp[MCFUART_UBG2] = (clk & 0xff);  /* set lsb baud */
      uartp[MCFUART_UCSR] = MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER;
      uartp[MCFUART_UCR] = MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE;

      mcfrs_console_inited++;
      return;
}


/*
 *    Setup for console. Argument comes from the boot command line.
 */

int mcfrs_console_setup(struct console *cp, char *arg)
{
      int         i, n = CONSOLE_BAUD_RATE;

      if (!cp)
            return(-1);

      if (!strncmp(cp->name, "ttyS", 4))
            mcfrs_console_port = cp->index;
      else if (!strncmp(cp->name, "cua", 3))
            mcfrs_console_port = cp->index;
      else
            return(-1);

      if (arg)
            n = simple_strtoul(arg,NULL,0);
      for (i = 0; i < MCFRS_BAUD_TABLE_SIZE; i++)
            if (mcfrs_baud_table[i] == n)
                  break;
      if (i < MCFRS_BAUD_TABLE_SIZE) {
            mcfrs_console_baud = n;
            mcfrs_console_cbaud = 0;
            if (i > 15) {
                  mcfrs_console_cbaud |= CBAUDEX;
                  i -= 15;
            }
            mcfrs_console_cbaud |= i;
      }
      mcfrs_init_console(); /* make sure baud rate changes */
      return(0);
}


static struct tty_driver *mcfrs_console_device(struct console *c, int *index)
{
      *index = c->index;
      return mcfrs_serial_driver;
}


/*
 *    Output a single character, using UART polled mode.
 *    This is used for console output.
 */

void mcfrs_put_char(char ch)
{
      volatile unsigned char  *uartp;
      unsigned long           flags;
      int               i;

      uartp = (volatile unsigned char *) (MCF_MBAR +
            (mcfrs_console_port ? MCFUART_BASE2 : MCFUART_BASE1));

      local_irq_save(flags);
      for (i = 0; (i < 0x10000); i++) {
            if (uartp[MCFUART_USR] & MCFUART_USR_TXREADY)
                  break;
      }
      if (i < 0x10000) {
            uartp[MCFUART_UTB] = ch;
            for (i = 0; (i < 0x10000); i++)
                  if (uartp[MCFUART_USR] & MCFUART_USR_TXEMPTY)
                        break;
      }
      if (i >= 0x10000)
            mcfrs_init_console(); /* try and get it back */
      local_irq_restore(flags);

      return;
}


/*
 * rs_console_write is registered for printk output.
 */

void mcfrs_console_write(struct console *cp, const char *p, unsigned len)
{
      if (!mcfrs_console_inited)
            mcfrs_init_console();
      while (len-- > 0) {
            if (*p == '\n')
                  mcfrs_put_char('\r');
            mcfrs_put_char(*p++);
      }
}

/*
 * declare our consoles
 */

struct console mcfrs_console = {
      .name       = "ttyS",
      .write            = mcfrs_console_write,
      .device           = mcfrs_console_device,
      .setup            = mcfrs_console_setup,
      .flags            = CON_PRINTBUFFER,
      .index            = -1,
};

static int __init mcfrs_console_init(void)
{
      register_console(&mcfrs_console);
      return 0;
}

console_initcall(mcfrs_console_init);

/****************************************************************************/

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