ircomm_tty.c

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			-EAGAIN : -ERESTARTSYS);
#else
		return -EAGAIN;
#endif
	}

	/* Check if this is a "normal" ircomm device, or an irlpt device */
	if (line < 0x10) {
		self->service_type = IRCOMM_3_WIRE | IRCOMM_9_WIRE;
		self->settings.service_type = IRCOMM_9_WIRE; /* Default */
		IRDA_DEBUG(2, __FUNCTION__ "(), IrCOMM device\n");
	} else {
		IRDA_DEBUG(2, __FUNCTION__ "(), IrLPT device\n");
		self->service_type = IRCOMM_3_WIRE_RAW;
		self->settings.service_type = IRCOMM_3_WIRE_RAW; /* Default */
	}

	ret = ircomm_tty_startup(self);
	if (ret)
		return ret;

	ret = ircomm_tty_block_til_ready(self, filp);
	if (ret) {
		/* MOD_DEC_USE_COUNT; "info->tty" will cause this? */
		IRDA_DEBUG(2, __FUNCTION__ 
		      "(), returning after block_til_ready with %d\n",
		      ret);

		return ret;
	}

	self->session = current->session;
	self->pgrp = current->pgrp;

	return 0;
}

/*
 * Function ircomm_tty_close (tty, filp)
 *
 *    This routine is called when a particular tty device is closed.
 *
 */
static void ircomm_tty_close(struct tty_struct *tty, struct file *filp)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;
	unsigned long flags;

	IRDA_DEBUG(0, __FUNCTION__ "()\n");

	if (!tty)
		return;

	save_flags(flags); 
	cli();

	if (tty_hung_up_p(filp)) {
		MOD_DEC_USE_COUNT;
		restore_flags(flags);

		IRDA_DEBUG(0, __FUNCTION__ "(), returning 1\n");
		return;
	}

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return;);

	if ((tty->count == 1) && (self->open_count != 1)) {
		/*
		 * Uh, oh.  tty->count is 1, which means that the tty
		 * structure will be freed.  state->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.
		 */
		IRDA_DEBUG(0, __FUNCTION__ "(), bad serial port count; "
			   "tty->count is 1, state->count is %d\n", 
			   self->open_count);
		self->open_count = 1;
	}

	if (--self->open_count < 0) {
		ERROR(__FUNCTION__ 
		      "(), bad serial port count for ttys%d: %d\n",
		      self->line, self->open_count);
		self->open_count = 0;
	}
	if (self->open_count) {
		MOD_DEC_USE_COUNT;
		restore_flags(flags);

		IRDA_DEBUG(0, __FUNCTION__ "(), open count > 0\n");
		return;
	}
	self->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 (self->closing_wait != ASYNC_CLOSING_WAIT_NONE)
		tty_wait_until_sent(tty, self->closing_wait);

	ircomm_tty_shutdown(self);

	if (tty->driver.flush_buffer)
		tty->driver.flush_buffer(tty);
	if (tty->ldisc.flush_buffer)
		tty->ldisc.flush_buffer(tty);

	tty->closing = 0;
	self->tty = 0;

	if (self->blocked_open) {
		if (self->close_delay) {
			current->state = TASK_INTERRUPTIBLE;
			schedule_timeout(self->close_delay);
		}
		wake_up_interruptible(&self->open_wait);
	}

	self->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CALLOUT_ACTIVE|
			 ASYNC_CLOSING);
	wake_up_interruptible(&self->close_wait);

	MOD_DEC_USE_COUNT;
	restore_flags(flags);
}

/*
 * Function ircomm_tty_flush_buffer (tty)
 *
 *    
 *
 */
static void ircomm_tty_flush_buffer(struct tty_struct *tty)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return;);

	/* 
	 * Let do_softint() do this to avoid race condition with 
	 * do_softint() ;-) 
	 */
	queue_task(&self->tqueue, &tq_immediate);
	mark_bh(IMMEDIATE_BH);
}

/*
 * Function ircomm_tty_do_softint (private_)
 *
 *    We use this routine to give the write wakeup to the user at at a
 *    safe time (as fast as possible after write have completed). This 
 *    can be compared to the Tx interrupt.
 */
static void ircomm_tty_do_softint(void *private_)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) private_;
	struct tty_struct *tty;
	unsigned long flags;
	struct sk_buff *skb, *ctrl_skb;

	IRDA_DEBUG(2, __FUNCTION__ "()\n");

	if (!self || self->magic != IRCOMM_TTY_MAGIC)
		return;

	tty = self->tty;
	if (!tty)
		return;

	/* Unlink control buffer */
	save_flags(flags);
	cli();

	ctrl_skb = self->ctrl_skb;
	self->ctrl_skb = NULL;

	restore_flags(flags);

	/* Flush control buffer if any */
	if (ctrl_skb && self->flow == FLOW_START)
		ircomm_control_request(self->ircomm, ctrl_skb);

	if (tty->hw_stopped)
		return;

	/* Unlink transmit buffer */
	save_flags(flags);
	cli();
	
	skb = self->tx_skb;
	self->tx_skb = NULL;

	restore_flags(flags);	

	/* Flush transmit buffer if any */
	if (skb)
		ircomm_tty_do_event(self, IRCOMM_TTY_DATA_REQUEST, skb, NULL);
		
	/* Check if user (still) wants to be waken up */
	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) && 
	    tty->ldisc.write_wakeup)
	{
		(tty->ldisc.write_wakeup)(tty);
	}
	wake_up_interruptible(&tty->write_wait);
}

/*
 * Function ircomm_tty_write (tty, from_user, buf, count)
 *
 *    This routine is called by the kernel to write a series of characters
 *    to the tty device. The characters may come from user space or kernel
 *    space. This routine will return the number of characters actually
 *    accepted for writing. This routine is mandatory.
 */
static int ircomm_tty_write(struct tty_struct *tty, int from_user,
			    const unsigned char *buf, int count)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;
	unsigned long flags;
	struct sk_buff *skb;
	int tailroom = 0;
	int len = 0;
	int size;

	IRDA_DEBUG(2, __FUNCTION__ "(), count=%d, hw_stopped=%d\n", count,
		   tty->hw_stopped);

	ASSERT(self != NULL, return -1;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	save_flags(flags);
	cli();

	/* Fetch current transmit buffer */
	skb = self->tx_skb;

	/*  
	 * Send out all the data we get, possibly as multiple fragmented
	 * frames, but this will only happen if the data is larger than the
	 * max data size. The normal case however is just the opposite, and
	 * this function may be called multiple times, and will then actually
	 * defragment the data and send it out as one packet as soon as 
	 * possible, but at a safer point in time
	 */
	while (count) {
		size = count;

		/* Adjust data size to the max data size */
		if (size > self->max_data_size)
			size = self->max_data_size;
		
		/* 
		 * Do we already have a buffer ready for transmit, or do
		 * we need to allocate a new frame 
		 */
		if (skb) {			
			/* 
			 * Any room for more data at the end of the current 
			 * transmit buffer? Cannot use skb_tailroom, since
			 * dev_alloc_skb gives us a larger skb than we 
			 * requested
			 */
			if ((tailroom = (self->max_data_size-skb->len)) > 0) {
				/* Adjust data to tailroom */
				if (size > tailroom)
					size = tailroom;
			} else {
				/* 
				 * Current transmit frame is full, so break 
				 * out, so we can send it as soon as possible
				 */
				break;
			}
		} else {
			/* Prepare a full sized frame */
			skb = dev_alloc_skb(self->max_data_size+
					    self->max_header_size);
			if (!skb) {
				restore_flags(flags);
				return -ENOBUFS;
			}
			skb_reserve(skb, self->max_header_size);
			self->tx_skb = skb;
		}
		
		/* Copy data */
		if (from_user)
			copy_from_user(skb_put(skb,size), buf+len, size);
		else
			memcpy(skb_put(skb,size), buf+len, size);
		
		count -= size;
		len += size;
	}

	restore_flags(flags);

	/*     
	 * Schedule a new thread which will transmit the frame as soon
	 * as possible, but at a safe point in time. We do this so the
	 * "user" can give us data multiple times, as PPP does (because of
	 * its 256 byte tx buffer). We will then defragment and send out
	 * all this data as one single packet.  
	 */
	queue_task(&self->tqueue, &tq_immediate);
	mark_bh(IMMEDIATE_BH);
	
	return len;
}

/*
 * Function ircomm_tty_write_room (tty)
 *
 *    This routine returns the numbers of characters the tty driver will
 *    accept for queuing to be written. This number is subject to change as
 *    output buffers get emptied, or if the output flow control is acted.
 */
static int ircomm_tty_write_room(struct tty_struct *tty)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;
	unsigned long flags;
	int ret;

	ASSERT(self != NULL, return -1;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	/* Check if we are allowed to transmit any data */
	if (tty->hw_stopped)
		ret = 0;
	else {
		save_flags(flags);
		cli();
		if (self->tx_skb)
			ret = self->max_data_size - self->tx_skb->len;
		else
			ret = self->max_data_size;
		restore_flags(flags);
	}
	IRDA_DEBUG(2, __FUNCTION__ "(), ret=%d\n", ret);

	return ret;
}

/*
 * Function ircomm_tty_wait_until_sent (tty, timeout)
 *
 *    This routine waits until the device has written out all of the
 *    characters in its transmitter FIFO.
 */
static void ircomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;
	unsigned long orig_jiffies, poll_time;
	
	IRDA_DEBUG(2, __FUNCTION__ "()\n");

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return;);

	orig_jiffies = jiffies;

	/* Set poll time to 200 ms */
	poll_time = IRDA_MIN(timeout, MSECS_TO_JIFFIES(200));

	while (self->tx_skb && self->tx_skb->len) {
		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout(poll_time);
		if (signal_pending(current))
			break;
		if (timeout && time_after(jiffies, orig_jiffies + timeout))
			break;
	}
	current->state = TASK_RUNNING;
}

/*
 * Function ircomm_tty_throttle (tty)
 *
 *    This routine notifies the tty driver that input buffers for the line
 *    discipline are close to full, and it should somehow signal that no
 *    more characters should be sent to the tty.  
 */
static void ircomm_tty_throttle(struct tty_struct *tty)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;

	IRDA_DEBUG(2, __FUNCTION__ "()\n");

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return;);

	/* Software flow control? */
	if (I_IXOFF(tty))
		ircomm_tty_send_xchar(tty, STOP_CHAR(tty));
	
	/* Hardware flow control? */
	if (tty->termios->c_cflag & CRTSCTS) {
		self->settings.dte &= ~IRCOMM_RTS;
		self->settings.dte |= IRCOMM_DELTA_RTS;
	
		ircomm_param_request(self, IRCOMM_DTE, TRUE);
	}

        ircomm_flow_request(self->ircomm, FLOW_STOP);
}

/*
 * Function ircomm_tty_unthrottle (tty)
 *
 *    This routine notifies the tty drivers that it should signals that
 *    characters can now be sent to the tty without fear of overrunning the
 *    input buffers of the line disciplines.
 */
static void ircomm_tty_unthrottle(struct tty_struct *tty)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;

	IRDA_DEBUG(2, __FUNCTION__ "()\n");

	ASSERT(self != NULL, return;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return;);

	/* Using software flow control? */
	if (I_IXOFF(tty)) {
		ircomm_tty_send_xchar(tty, START_CHAR(tty));
	}

	/* Using hardware flow control? */
	if (tty->termios->c_cflag & CRTSCTS) {
		self->settings.dte |= (IRCOMM_RTS|IRCOMM_DELTA_RTS);

		ircomm_param_request(self, IRCOMM_DTE, TRUE);
		IRDA_DEBUG(1, __FUNCTION__"(), FLOW_START\n");
	}
        ircomm_flow_request(self->ircomm, FLOW_START);
}

/*
 * Function ircomm_tty_chars_in_buffer (tty)
 *
 *    Indicates if there are any data in the buffer
 *
 */
static int ircomm_tty_chars_in_buffer(struct tty_struct *tty)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) tty->driver_data;
	unsigned long flags;
	int len = 0;

	ASSERT(self != NULL, return -1;);
	ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	save_flags(flags);
	cli();