serial167.c

powerpc内核mpc8241linux系统下char驱动程序

#ifdef SERIAL_DEBUG_OPEN
    printk("cy_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("cy_close: bad serial port count; tty->count is 1, "
	   "info->count is %d\n", info->count);
	info->count = 1;
    }
#ifdef SERIAL_DEBUG_COUNT
    printk("cyc: %d: decrementing count to %d\n", __LINE__, info->count - 1);
#endif
    if (--info->count < 0) {
	printk("cy_close: bad serial port count for ttys%d: %d\n",
	       info->line, info->count);
#ifdef SERIAL_DEBUG_COUNT
    printk("cyc: %d: setting count to 0\n", __LINE__);
#endif
	info->count = 0;
    }
    if (info->count)
	return;
    info->flags |= ASYNC_CLOSING;
    /*
     * Save the termios structure, since this port may have
     * separate termios for callout and dialin.
     */
    if (info->flags & ASYNC_NORMAL_ACTIVE)
	info->normal_termios = *tty->termios;
    if (info->flags & ASYNC_CALLOUT_ACTIVE)
	info->callout_termios = *tty->termios;
    if (info->flags & ASYNC_INITIALIZED)
	tty_wait_until_sent(tty, 3000); /* 30 seconds timeout */
    shutdown(info);
    if (tty->driver.flush_buffer)
	tty->driver.flush_buffer(tty);
    if (tty->ldisc.flush_buffer)
	tty->ldisc.flush_buffer(tty);
    info->event = 0;
    info->tty = 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);
    }
    if (info->blocked_open) {
	if (info->close_delay) {
	    current->state = TASK_INTERRUPTIBLE;
	    schedule_timeout(info->close_delay);
	}
	wake_up_interruptible(&info->open_wait);
    }
    info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE|
		     ASYNC_CLOSING);
    wake_up_interruptible(&info->close_wait);

#ifdef SERIAL_DEBUG_OTHER
    printk("cy_close done\n");
#endif

    return;
} /* cy_close */

/*
 * cy_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
void
cy_hangup(struct tty_struct *tty)
{
  struct cyclades_port * info = (struct cyclades_port *)tty->driver_data;
	
#ifdef SERIAL_DEBUG_OTHER
    printk("cy_hangup ttyS%d\n", info->line); /* */
#endif

    if (serial_paranoia_check(info, tty->device, "cy_hangup"))
	return;
    
    shutdown(info);
#if 0
    info->event = 0;
    info->count = 0;
#ifdef SERIAL_DEBUG_COUNT
    printk("cyc: %d: setting count to 0\n", __LINE__);
#endif
    info->tty = 0;
#endif
    info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE);
    wake_up_interruptible(&info->open_wait);
} /* cy_hangup */



/*
 * ------------------------------------------------------------
 * cy_open() and friends
 * ------------------------------------------------------------
 */

static int
block_til_ready(struct tty_struct *tty, struct file * filp,
                           struct cyclades_port *info)
{
  struct wait_queue wait = { current, NULL };
  unsigned long flags;
  int channel;
  int retval;
  volatile u_char *base_addr = (u_char *)BASE_ADDR;

    /*
     * 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);
	if (info->flags & ASYNC_HUP_NOTIFY){
	    return -EAGAIN;
	}else{
	    return -ERESTARTSYS;
	}
    }

    /*
     * If this is a callout device, then just make sure the normal
     * device isn't being used.
     */
    if (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
	if (info->flags & ASYNC_NORMAL_ACTIVE){
	    return -EBUSY;
	}
	if ((info->flags & ASYNC_CALLOUT_ACTIVE) &&
	    (info->flags & ASYNC_SESSION_LOCKOUT) &&
	    (info->session != current->session)){
	    return -EBUSY;
	}
	if ((info->flags & ASYNC_CALLOUT_ACTIVE) &&
	    (info->flags & ASYNC_PGRP_LOCKOUT) &&
	    (info->pgrp != current->pgrp)){
	    return -EBUSY;
	}
	info->flags |= ASYNC_CALLOUT_ACTIVE;
	return 0;
    }

    /*
     * If non-blocking mode is set, then make the check up front
     * and then exit.
     */
    if (filp->f_flags & O_NONBLOCK) {
	if (info->flags & ASYNC_CALLOUT_ACTIVE){
	    return -EBUSY;
	}
	info->flags |= ASYNC_NORMAL_ACTIVE;
	return 0;
    }

    /*
     * 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
     * cy_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--;
#ifdef SERIAL_DEBUG_COUNT
    printk("cyc: %d: decrementing count to %d\n", __LINE__, info->count);
#endif
    info->blocked_open++;

    channel = info->line;

    while (1) {
	save_flags(flags); cli();
	    if (!(info->flags & ASYNC_CALLOUT_ACTIVE)){
		base_addr[CyCAR] = (u_char)channel;
		base_addr[CyMSVR1] = CyRTS;
/* CP('S');CP('4'); */
		base_addr[CyMSVR2] = CyDTR;
#ifdef SERIAL_DEBUG_DTR
                printk("cyc: %d: raising DTR\n", __LINE__);
                printk("     status: 0x%x, 0x%x\n", base_addr[CyMSVR1], base_addr[CyMSVR2]);
#endif
	    }
	restore_flags(flags);
	current->state = TASK_INTERRUPTIBLE;
	if (tty_hung_up_p(filp)
	|| !(info->flags & ASYNC_INITIALIZED) ){
	    if (info->flags & ASYNC_HUP_NOTIFY) {
		retval = -EAGAIN;
	    }else{
		retval = -ERESTARTSYS;
	    }
	    break;
	}
	save_flags(flags); cli();
	    base_addr[CyCAR] = (u_char)channel;
/* CP('L');CP1(1 && C_CLOCAL(tty)); CP1(1 && (base_addr[CyMSVR1] & CyDCD) ); */
	    if (!(info->flags & ASYNC_CALLOUT_ACTIVE)
	    && !(info->flags & ASYNC_CLOSING)
	    && (C_CLOCAL(tty)
	        || (base_addr[CyMSVR1] & CyDCD))) {
		    restore_flags(flags);
		    break;
	    }
	restore_flags(flags);
	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++;
#ifdef SERIAL_DEBUG_COUNT
    printk("cyc: %d: incrementing count to %d\n", __LINE__, info->count);
#endif
    }
    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;
} /* block_til_ready */

/*
 * This routine is called whenever a serial port is opened.  It
 * performs the serial-specific initialization for the tty structure.
 */
int
cy_open(struct tty_struct *tty, struct file * filp)
{
  struct cyclades_port  *info;
  int retval, line;

/* CP('O'); */
    line = MINOR(tty->device) - tty->driver.minor_start;
    if ((line < 0) || (NR_PORTS <= line)){
        return -ENODEV;
    }
    info = &cy_port[line];
    if (info->line < 0){
        return -ENODEV;
    }
#ifdef SERIAL_DEBUG_OTHER
    printk("cy_open ttyS%d\n", info->line); /* */
#endif
    if (serial_paranoia_check(info, tty->device, "cy_open")){
        return -ENODEV;
    }
#ifdef SERIAL_DEBUG_OPEN
    printk("cy_open ttyS%d, count = %d\n", info->line, info->count);/**/
#endif
    info->count++;
#ifdef SERIAL_DEBUG_COUNT
    printk("cyc: %d: incrementing count to %d\n", __LINE__, info->count);
#endif
    tty->driver_data = info;
    info->tty = tty;

    if (!tmp_buf) {
	tmp_buf = (unsigned char *) get_free_page(GFP_KERNEL);
	if (!tmp_buf){
	    return -ENOMEM;
        }
    }

    if ((info->count == 1) && (info->flags & ASYNC_SPLIT_TERMIOS)) {
	if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
	    *tty->termios = info->normal_termios;
	else 
	    *tty->termios = info->callout_termios;
    }
    /*
     * 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("cy_open returning after block_til_ready with %d\n",
	       retval);
#endif
	return retval;
    }

    info->session = current->session;
    info->pgrp = current->pgrp;

#ifdef SERIAL_DEBUG_OPEN
    printk("cy_open done\n");/**/
#endif
    return 0;
} /* cy_open */



/*
 * ---------------------------------------------------------------------
 * serial167_init() and friends
 *
 * serial167_init() is called at boot-time to initialize the serial driver.
 * ---------------------------------------------------------------------
 */

/*
 * This routine prints out the appropriate serial driver version
 * number, and identifies which options were configured into this
 * driver.
 */
static void
show_version(void)
{
    printk("MVME166/167 cd2401 driver\n");
} /* show_version */

/* initialize chips on card -- return number of valid
   chips (which is number of ports/4) */

/*
 * This initialises the hardware to a reasonable state.  It should
 * probe the chip first so as to copy 166-Bug setup as a default for
 * port 0.  It initialises CMR to CyASYNC; that is never done again, so
 * as to limit the number of CyINIT_CHAN commands in normal running.
 *
 * ... I wonder what I should do if this fails ...
 */

void
mvme167_serial_console_setup(int cflag)
{
	volatile unsigned char* base_addr = (u_char *)BASE_ADDR;
	int ch;
	u_char spd;
	u_char rcor, rbpr, badspeed = 0;
	unsigned long flags;

	save_flags(flags); cli();

	/*
	 * First probe channel zero of the chip, to see what speed has
	 * been selected.
	 */

	base_addr[CyCAR] = 0;

	rcor = base_addr[CyRCOR] << 5;
	rbpr = base_addr[CyRBPR];

	for (spd = 0; spd < sizeof(baud_bpr); spd++)
		if (rbpr == baud_bpr[spd] && rcor == baud_co[spd])
			break;
	if (spd >= sizeof(baud_bpr)) {
		spd = 14;	/* 19200 */
		badspeed = 1;	/* Failed to identify speed */
	}
	initial_console_speed = spd;

	/* OK, we have chosen a speed, now reset and reinitialise */

        my_udelay(20000L);	/* Allow time for any active o/p to complete */
        if(base_addr[CyCCR] != 0x00){
            /* printk(" chip is never idle (CCR != 0)\n"); */
            return;
        }

        base_addr[CyCCR] = CyCHIP_RESET;	/* Reset the chip */
        my_udelay(1000L);

        if(base_addr[CyGFRCR] == 0x00){
            /* printk(" chip is not responding (GFRCR stayed 0)\n"); */
            return;
        }

	/*
	 * System clock is 20Mhz, divided by 2048, so divide by 10 for a 1.0ms
	 * tick
	 */

	base_addr[CyTPR] = 10;

	base_addr[CyPILR1] = 0x01;    /* Interrupt level for modem change */
	base_addr[CyPILR2] = 0x02;    /* Interrupt level for tx ints */
	base_addr[CyPILR3] = 0x03;    /* Interrupt level for rx ints */

	/*
	 * Attempt to set up all channels to something reasonable, and
	 * bang out a INIT_CHAN command.  We should then be able to limit
	 * the ammount of fiddling we have to do in normal running.
	 */

	for (ch = 3; ch >= 0 ; ch--) {
		base_addr[CyCAR] = (u_char)ch;
		base_addr[CyIER] = 0;
		base_addr[CyCMR] = CyASYNC;
		base_addr[CyLICR] = (u_char)ch << 2;
		base_addr[CyLIVR] = 0x5c;
		base_addr[CyTCOR] = baud_co[spd];
		base_addr[CyTBPR] = baud_bpr[spd];
		base_addr[CyRCOR] = baud_co[spd] >> 5;
		base_addr[CyRBPR] = baud_bpr[spd];
		base_addr[CySCHR1] = 'Q' & 0x1f;
		base_addr[CySCHR2] = 'X' & 0x1f;
		base_addr[CySCRL] = 0;
		base_addr[CySCRH] = 0;
		base_addr[CyCOR1] = Cy_8_BITS | CyPARITY_NONE;
		base_addr[CyCOR2] = 0;
		base_addr[CyCOR3] = Cy_1_STOP;
		base_addr[CyCOR4] = baud_cor4[spd];
		base_addr[CyCOR5] = 0;
		base_addr[CyCOR6] = 0;
		base_addr[CyCOR7] = 0;
		base_addr[CyRTPRL] = 2;
		base_addr[CyRTPRH] = 0;
	        base_addr[CyMSVR1] = 0;
	        base_addr[CyMSVR2] = 0;
		write_cy_cmd(base_addr,CyINIT_CHAN|CyDIS_RCVR|CyDIS_XMTR);
	}

	/*
	 * Now do specials for channel zero....
	 */

        base_addr[CyMSVR1] = CyRTS;
        base_addr[CyMSVR2] = CyDTR;
	base_addr[CyIER] = CyRxData;
	write_cy_cmd(base_addr,CyENB_RCVR|CyENB_XMTR);

	restore_flags(flags);

	my_udelay(20000L);	/* Let it all settle down */

        printk("CD2401 initialised,  chip is rev 0x%02x\n", base_addr[CyGFRCR]);
	if (badspeed)
        	printk("  WARNING:  Failed to identify line speed, rcor=%02x,rbpr=%02x\n",
					rcor >> 5, rbpr);
} /* serial_console_init */

/* The serial driver boot-time initialization code!
    Hardware I/O ports are mapped to character special devices on a
    first found, f