moxa.c

linux 内核源代码

	}
	if (!MoxaPortIsValid(port)) {
		tty->driver_data = NULL;
		return (-ENODEV);
	}

	ch = &moxa_ports[port];
	ch->count++;
	tty->driver_data = ch;
	ch->tty = tty;
	if (!(ch->asyncflags & ASYNC_INITIALIZED)) {
		ch->statusflags = 0;
		moxa_set_tty_param(tty);
		MoxaPortLineCtrl(ch->port, 1, 1);
		MoxaPortEnable(ch->port);
		ch->asyncflags |= ASYNC_INITIALIZED;
	}
	retval = moxa_block_till_ready(tty, filp, ch);

	moxa_unthrottle(tty);

	if (ch->type == PORT_16550A) {
		MoxaSetFifo(ch->port, 1);
	} else {
		MoxaSetFifo(ch->port, 0);
	}

	return (retval);
}

static void moxa_close(struct tty_struct *tty, struct file *filp)
{
	struct moxa_port *ch;
	int port;

	port = tty->index;
	if (port == MAX_PORTS) {
		return;
	}
	if (!MoxaPortIsValid(port)) {
		pr_debug("Invalid portno in moxa_close\n");
		tty->driver_data = NULL;
		return;
	}
	if (tty->driver_data == NULL) {
		return;
	}
	if (tty_hung_up_p(filp)) {
		return;
	}
	ch = (struct moxa_port *) tty->driver_data;

	if ((tty->count == 1) && (ch->count != 1)) {
		printk(KERN_WARNING "moxa_close: bad serial port count; "
			"tty->count is 1, ch->count is %d\n", ch->count);
		ch->count = 1;
	}
	if (--ch->count < 0) {
		printk(KERN_WARNING "moxa_close: bad serial port count, "
			"device=%s\n", tty->name);
		ch->count = 0;
	}
	if (ch->count) {
		return;
	}
	ch->asyncflags |= ASYNC_CLOSING;

	ch->cflag = tty->termios->c_cflag;
	if (ch->asyncflags & ASYNC_INITIALIZED) {
		moxa_setup_empty_event(tty);
		tty_wait_until_sent(tty, 30 * HZ);	/* 30 seconds timeout */
		del_timer_sync(&moxa_ports[ch->port].emptyTimer);
	}
	moxa_shut_down(ch);
	MoxaPortFlushData(port, 2);

	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);
	tty_ldisc_flush(tty);
			
	tty->closing = 0;
	ch->event = 0;
	ch->tty = NULL;
	if (ch->blocked_open) {
		if (ch->close_delay) {
			msleep_interruptible(jiffies_to_msecs(ch->close_delay));
		}
		wake_up_interruptible(&ch->open_wait);
	}
	ch->asyncflags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
	complete_all(&ch->close_wait);
}

static int moxa_write(struct tty_struct *tty,
		      const unsigned char *buf, int count)
{
	struct moxa_port *ch;
	int len, port;
	unsigned long flags;

	ch = (struct moxa_port *) tty->driver_data;
	if (ch == NULL)
		return (0);
	port = ch->port;

	spin_lock_irqsave(&moxa_lock, flags);
	len = MoxaPortWriteData(port, (unsigned char *) buf, count);
	spin_unlock_irqrestore(&moxa_lock, flags);

	/*********************************************
	if ( !(ch->statusflags & LOWWAIT) &&
	     ((len != count) || (MoxaPortTxFree(port) <= 100)) )
	************************************************/
	ch->statusflags |= LOWWAIT;
	return (len);
}

static int moxa_write_room(struct tty_struct *tty)
{
	struct moxa_port *ch;

	if (tty->stopped)
		return (0);
	ch = (struct moxa_port *) tty->driver_data;
	if (ch == NULL)
		return (0);
	return (MoxaPortTxFree(ch->port));
}

static void moxa_flush_buffer(struct tty_struct *tty)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	if (ch == NULL)
		return;
	MoxaPortFlushData(ch->port, 1);
	tty_wakeup(tty);
}

static int moxa_chars_in_buffer(struct tty_struct *tty)
{
	int chars;
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	/*
	 * Sigh...I have to check if driver_data is NULL here, because
	 * if an open() fails, the TTY subsystem eventually calls
	 * tty_wait_until_sent(), which calls the driver's chars_in_buffer()
	 * routine.  And since the open() failed, we return 0 here.  TDJ
	 */
	if (ch == NULL)
		return (0);
	chars = MoxaPortTxQueue(ch->port);
	if (chars) {
		/*
		 * Make it possible to wakeup anything waiting for output
		 * in tty_ioctl.c, etc.
		 */
		if (!(ch->statusflags & EMPTYWAIT))
			moxa_setup_empty_event(tty);
	}
	return (chars);
}

static void moxa_flush_chars(struct tty_struct *tty)
{
	/*
	 * Don't think I need this, because this is called to empty the TX
	 * buffer for the 16450, 16550, etc.
	 */
}

static void moxa_put_char(struct tty_struct *tty, unsigned char c)
{
	struct moxa_port *ch;
	int port;
	unsigned long flags;

	ch = (struct moxa_port *) tty->driver_data;
	if (ch == NULL)
		return;
	port = ch->port;
	spin_lock_irqsave(&moxa_lock, flags);
	MoxaPortWriteData(port, &c, 1);
	spin_unlock_irqrestore(&moxa_lock, flags);
	/************************************************
	if ( !(ch->statusflags & LOWWAIT) && (MoxaPortTxFree(port) <= 100) )
	*************************************************/
	ch->statusflags |= LOWWAIT;
}

static int moxa_tiocmget(struct tty_struct *tty, struct file *file)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;
	int port;
	int flag = 0, dtr, rts;

	port = tty->index;
	if ((port != MAX_PORTS) && (!ch))
		return (-EINVAL);

	MoxaPortGetLineOut(ch->port, &dtr, &rts);
	if (dtr)
		flag |= TIOCM_DTR;
	if (rts)
		flag |= TIOCM_RTS;
	dtr = MoxaPortLineStatus(ch->port);
	if (dtr & 1)
		flag |= TIOCM_CTS;
	if (dtr & 2)
		flag |= TIOCM_DSR;
	if (dtr & 4)
		flag |= TIOCM_CD;
	return flag;
}

static int moxa_tiocmset(struct tty_struct *tty, struct file *file,
			 unsigned int set, unsigned int clear)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;
	int port;
	int dtr, rts;

	port = tty->index;
	if ((port != MAX_PORTS) && (!ch))
		return (-EINVAL);

	MoxaPortGetLineOut(ch->port, &dtr, &rts);
	if (set & TIOCM_RTS)
		rts = 1;
	if (set & TIOCM_DTR)
		dtr = 1;
	if (clear & TIOCM_RTS)
		rts = 0;
	if (clear & TIOCM_DTR)
		dtr = 0;
	MoxaPortLineCtrl(ch->port, dtr, rts);
	return 0;
}

static int moxa_ioctl(struct tty_struct *tty, struct file *file,
		      unsigned int cmd, unsigned long arg)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;
	register int port;
	void __user *argp = (void __user *)arg;
	int retval;

	port = tty->index;
	if ((port != MAX_PORTS) && (!ch))
		return (-EINVAL);

	switch (cmd) {
	case TCSBRK:		/* SVID version: non-zero arg --> no break */
		retval = tty_check_change(tty);
		if (retval)
			return (retval);
		moxa_setup_empty_event(tty);
		tty_wait_until_sent(tty, 0);
		if (!arg)
			MoxaPortSendBreak(ch->port, 0);
		return (0);
	case TCSBRKP:		/* support for POSIX tcsendbreak() */
		retval = tty_check_change(tty);
		if (retval)
			return (retval);
		moxa_setup_empty_event(tty);
		tty_wait_until_sent(tty, 0);
		MoxaPortSendBreak(ch->port, arg);
		return (0);
	case TIOCGSOFTCAR:
		return put_user(C_CLOCAL(tty) ? 1 : 0, (unsigned long __user *) argp);
	case TIOCSSOFTCAR:
		if(get_user(retval, (unsigned long __user *) argp))
			return -EFAULT;
		arg = retval;
		tty->termios->c_cflag = ((tty->termios->c_cflag & ~CLOCAL) |
					 (arg ? CLOCAL : 0));
		if (C_CLOCAL(tty))
			ch->asyncflags &= ~ASYNC_CHECK_CD;
		else
			ch->asyncflags |= ASYNC_CHECK_CD;
		return (0);
	case TIOCGSERIAL:
		return moxa_get_serial_info(ch, argp);

	case TIOCSSERIAL:
		return moxa_set_serial_info(ch, argp);
	default:
		retval = MoxaDriverIoctl(cmd, arg, port);
	}
	return (retval);
}

static void moxa_throttle(struct tty_struct *tty)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	ch->statusflags |= THROTTLE;
}

static void moxa_unthrottle(struct tty_struct *tty)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	ch->statusflags &= ~THROTTLE;
}

static void moxa_set_termios(struct tty_struct *tty,
			     struct ktermios *old_termios)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	if (ch == NULL)
		return;
	moxa_set_tty_param(tty);
	if (!(old_termios->c_cflag & CLOCAL) &&
	    (tty->termios->c_cflag & CLOCAL))
		wake_up_interruptible(&ch->open_wait);
}

static void moxa_stop(struct tty_struct *tty)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	if (ch == NULL)
		return;
	MoxaPortTxDisable(ch->port);
	ch->statusflags |= TXSTOPPED;
}


static void moxa_start(struct tty_struct *tty)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	if (ch == NULL)
		return;

	if (!(ch->statusflags & TXSTOPPED))
		return;

	MoxaPortTxEnable(ch->port);
	ch->statusflags &= ~TXSTOPPED;
}

static void moxa_hangup(struct tty_struct *tty)
{
	struct moxa_port *ch = (struct moxa_port *) tty->driver_data;

	moxa_flush_buffer(tty);
	moxa_shut_down(ch);
	ch->event = 0;
	ch->count = 0;
	ch->asyncflags &= ~ASYNC_NORMAL_ACTIVE;
	ch->tty = NULL;
	wake_up_interruptible(&ch->open_wait);
}

static void moxa_poll(unsigned long ignored)
{
	register int card;
	struct moxa_port *ch;
	struct tty_struct *tp;
	int i, ports;

	del_timer(&moxaTimer);

	if (MoxaDriverPoll() < 0) {
		mod_timer(&moxaTimer, jiffies + HZ / 50);
		return;
	}
	for (card = 0; card < MAX_BOARDS; card++) {
		if ((ports = MoxaPortsOfCard(card)) <= 0)
			continue;
		ch = &moxa_ports[card * MAX_PORTS_PER_BOARD];
		for (i = 0; i < ports; i++, ch++) {
			if ((ch->asyncflags & ASYNC_INITIALIZED) == 0)
				continue;
			if (!(ch->statusflags & THROTTLE) &&
			    (MoxaPortRxQueue(ch->port) > 0))
				moxa_receive_data(ch);
			if ((tp = ch->tty) == 0)
				continue;
			if (ch->statusflags & LOWWAIT) {
				if (MoxaPortTxQueue(ch->port) <= WAKEUP_CHARS) {
					if (!tp->stopped) {
						ch->statusflags &= ~LOWWAIT;
						tty_wakeup(tp);
					}
				}
			}
			if (!I_IGNBRK(tp) && (MoxaPortResetBrkCnt(ch->port) > 0)) {
				tty_insert_flip_char(tp, 0, TTY_BREAK);
				tty_schedule_flip(tp);
			}
			if (MoxaPortDCDChange(ch->port)) {
				if (ch->asyncflags & ASYNC_CHECK_CD) {
					if (MoxaPortDCDON(ch->port))
						wake_up_interruptible(&ch->open_wait);
					else {
						tty_hangup(tp);
						wake_up_interruptible(&ch->open_wait);
						ch->asyncflags &= ~ASYNC_NORMAL_ACTIVE;
					}
				}
			}
		}
	}

	mod_timer(&moxaTimer, jiffies + HZ / 50);
}

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

static void moxa_set_tty_param(struct tty_struct *tty)
{
	register struct ktermios *ts;
	struct moxa_port *ch;
	int rts, cts, txflow, rxflow, xany;

	ch = (struct moxa_port *) tty->driver_data;
	ts = tty->termios;
	if (ts->c_cflag & CLOCAL)
		ch->asyncflags &= ~ASYNC_CHECK_CD;
	else
		ch->asyncflags |= ASYNC_CHECK_CD;
	rts = cts = txflow = rxflow = xany = 0;
	if (ts->c_cflag & CRTSCTS)
		rts = cts = 1;
	if (ts->c_iflag & IXON)
		txflow = 1;
	if (ts->c_iflag & IXOFF)
		rxflow = 1;
	if (ts->c_iflag & IXANY)
		xany = 1;
	MoxaPortFlowCtrl(ch->port, rts, cts, txflow, rxflow, xany);
	MoxaPortSetTermio(ch->port, ts, tty_get_baud_rate(tty));
}

static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,
			    struct moxa_port *ch)
{
	DECLARE_WAITQUEUE(wait,current);
	unsigned long flags;
	int retval;
	int do_clocal = C_CLOCAL(tty);

	/*
	 * If the device is in the middle of being closed, then block
	 * until it's done, and then try again.
	 */
	if (tty_hung_up_p(filp) || (ch->asyncflags & ASYNC_CLOSING)) {
		if (ch->asyncflags & ASYNC_CLOSING)
			wait_for_completion_interruptible(&ch->close_wait);
#ifdef SERIAL_DO_RESTART
		if (ch->asyncflags & ASYNC_HUP_NOTIFY)
			return (-EAGAIN);
		else
			return (-ERESTARTSYS);
#else
		return (-EAGAIN);
#endif
	}
	/*
	 * If non-blocking mode is set, then make the check up front
	 * and then exit.
	 */
	if (filp->f_flags & O_NONBLOCK) {
		ch->asyncflags |= ASYNC_NORMAL_ACTIVE;
		return (0);
	}
	/*
	 * Block waiting for the carrier detect and the line to become free
	 */
	retval = 0;
	add_wait_queue(&ch->open_wait, &wait);
	pr_debug("block_til_ready before block: ttys%d, count = %d\n",
		ch->port, ch->count);
	spin_lock_irqsave(&moxa_lock, flags);
	if (!tty_hung_up_p(filp))
		ch->count--;
	ch->blocked_open++;
	spin_unlock_irqrestore(&moxa_lock, flags);

	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (tty_hung_up_p(filp) ||
		    !(ch->asyncflags & ASYNC_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART