mcfserial.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,892 行 · 第 1/4 页

	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;
	current->state = TASK_INTERRUPTIBLE;
	uartp = info->addr;

	local_irq_save(flags);
	uartp[MCFUART_UCR] = MCFUART_UCR_CMDBREAKSTART;
	schedule_timeout(jiffies + 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:
			error = verify_area(VERIFY_WRITE, (void *) arg,
						sizeof(struct serial_struct));
			if (error)
				return error;
			return get_serial_info(info,
					       (struct serial_struct *) arg);
		case TIOCSSERIAL:
			return set_serial_info(info,
					       (struct serial_struct *) arg);
		case TIOCSERGETLSR: /* Get line status register */
			error = verify_area(VERIFY_WRITE, (void *) arg,
				sizeof(unsigned int));
			if (error)
				return error;
			else
			    return get_lsr_info(info, (unsigned int *) arg);

		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 termios *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) {
			current->state = TASK_INTERRUPTIBLE;
			schedule_timeout(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;
		set_current_state(TASK_INTERRUPTIBLE);
		schedule_timeout(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;