Commit 31f35939 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

tty_port: Add a port level carrier detect operation 



This is the first step to generalising the various pieces of waiting logic
duplicated in all sorts of serial drivers.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c9b3976e

drivers/char/esp.c

+37 −24
Original line number Diff line number Diff line
@@ -2054,6 +2054,15 @@ static void esp_hangup(struct tty_struct *tty) 
	wake_up_interruptible(&info->port.open_wait);

}



static int esp_carrier_raised(struct tty_port *port)

{

	struct esp_struct *info = container_of(port, struct esp_struct, port);

	serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);

	if (serial_in(info, UART_ESI_STAT2) & UART_MSR_DCD)

		return 1;

	return 0;

}



/*

 * ------------------------------------------------------------

 * esp_open() and friends
@@ -2066,17 +2075,19 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	int		retval;

	int		do_clocal = 0;

	unsigned long	flags;

	int		cd;

	struct tty_port *port = &info->port;



	/*

	 * 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) ||

	    (info->port.flags & ASYNC_CLOSING)) {

		if (info->port.flags & ASYNC_CLOSING)

			interruptible_sleep_on(&info->port.close_wait);

	    (port->flags & ASYNC_CLOSING)) {

		if (port->flags & ASYNC_CLOSING)

			interruptible_sleep_on(&port->close_wait);

#ifdef SERIAL_DO_RESTART

		if (info->port.flags & ASYNC_HUP_NOTIFY)

		if (port->flags & ASYNC_HUP_NOTIFY)

			return -EAGAIN;

		else

			return -ERESTARTSYS;
@@ -2091,7 +2102,7 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	 */

	if ((filp->f_flags & O_NONBLOCK) ||

	    (tty->flags & (1 << TTY_IO_ERROR))) {

		info->port.flags |= ASYNC_NORMAL_ACTIVE;

		port->flags |= ASYNC_NORMAL_ACTIVE;

		return 0;

	}
@@ -2101,20 +2112,20 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	/*

	 * 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->port.count is dropped by one, so that

	 * this loop, port->count is dropped by one, so that

	 * rs_close() knows when to free things.  We restore it upon

	 * exit, either normal or abnormal.

	 */

	retval = 0;

	add_wait_queue(&info->port.open_wait, &wait);

	add_wait_queue(&port->open_wait, &wait);

#ifdef SERIAL_DEBUG_OPEN

	printk(KERN_DEBUG "block_til_ready before block: ttys%d, count = %d\n",

	       info->line, info->port.count);

	       info->line, port->count);

#endif

	spin_lock_irqsave(&info->lock, flags);

	if (!tty_hung_up_p(filp))

		info->port.count--;

	info->port.blocked_open++;

		port->count--;

	port->blocked_open++;

	while (1) {

		if ((tty->termios->c_cflag & CBAUD)) {

			unsigned int scratch;
@@ -2129,9 +2140,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
		}

		set_current_state(TASK_INTERRUPTIBLE);

		if (tty_hung_up_p(filp) ||

		    !(info->port.flags & ASYNC_INITIALIZED)) {

		    !(port->flags & ASYNC_INITIALIZED)) {

#ifdef SERIAL_DO_RESTART

			if (info->port.flags & ASYNC_HUP_NOTIFY)

			if (port->flags & ASYNC_HUP_NOTIFY)

				retval = -EAGAIN;

			else

				retval = -ERESTARTSYS;
@@ -2141,11 +2152,9 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
			break;

		}



		serial_out(info, UART_ESI_CMD1, ESI_GET_UART_STAT);

		if (serial_in(info, UART_ESI_STAT2) & UART_MSR_DCD)

			do_clocal = 1;

		cd = tty_port_carrier_raised(port);



		if (!(info->port.flags & ASYNC_CLOSING) &&

		if (!(port->flags & ASYNC_CLOSING) &&

		    (do_clocal))

			break;

		if (signal_pending(current)) {
@@ -2154,25 +2163,25 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
		}

#ifdef SERIAL_DEBUG_OPEN

		printk(KERN_DEBUG "block_til_ready blocking: ttys%d, count = %d\n",

		       info->line, info->port.count);

		       info->line, port->count);

#endif

		spin_unlock_irqrestore(&info->lock, flags);

		schedule();

		spin_lock_irqsave(&info->lock, flags);

	}

	set_current_state(TASK_RUNNING);

	remove_wait_queue(&info->port.open_wait, &wait);

	remove_wait_queue(&port->open_wait, &wait);

	if (!tty_hung_up_p(filp))

		info->port.count++;

	info->port.blocked_open--;

		port->count++;

	port->blocked_open--;

	spin_unlock_irqrestore(&info->lock, flags);

#ifdef SERIAL_DEBUG_OPEN

	printk(KERN_DEBUG "block_til_ready after blocking: ttys%d, count = %d\n",

	       info->line, info->port.count);

	       info->line, port->count);

#endif

	if (retval)

		return retval;

	info->port.flags |= ASYNC_NORMAL_ACTIVE;

	port->flags |= ASYNC_NORMAL_ACTIVE;

	return 0;

}
@@ -2329,6 +2338,10 @@ static const struct tty_operations esp_ops = { 
	.tiocmset = esp_tiocmset,

};



static const struct tty_port_operations esp_port_ops = {

	.esp_carrier_raised,

};



/*

 * The serial driver boot-time initialization code!

 */
@@ -2415,6 +2428,8 @@ static int __init espserial_init(void) 
	offset = 0;



	do {

		tty_port_init(&info->port);

		info->port.ops = &esp_port_ops;

		info->io_port = esp[i] + offset;

		info->irq = irq[i];

		info->line = (i * 8) + (offset / 8);
@@ -2437,8 +2452,6 @@ static int __init espserial_init(void) 
		info->config.flow_off = flow_off;

		info->config.pio_threshold = pio_threshold;

		info->next_port = ports;

		init_waitqueue_head(&info->port.open_wait);

		init_waitqueue_head(&info->port.close_wait);

		init_waitqueue_head(&info->delta_msr_wait);

		init_waitqueue_head(&info->break_wait);

		ports = info;

drivers/char/generic_serial.c

+22 −21
Original line number Diff line number Diff line
@@ -397,7 +397,8 @@ void gs_hangup(struct tty_struct *tty) 


int gs_block_til_ready(void *port_, struct file * filp)

{

	struct gs_port *port = port_;

	struct gs_port *gp = port_;

	struct tty_port *port = &gp->port;

	DECLARE_WAITQUEUE(wait, current);

	int    retval;

	int    do_clocal = 0;
@@ -409,16 +410,16 @@ int gs_block_til_ready(void *port_, struct file * filp) 


	if (!port) return 0;



	tty = port->port.tty;

	tty = port->tty;



	gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n"); 

	/*

	 * 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) || port->port.flags & ASYNC_CLOSING) {

		interruptible_sleep_on(&port->port.close_wait);

		if (port->port.flags & ASYNC_HUP_NOTIFY)

	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {

		interruptible_sleep_on(&port->close_wait);

		if (port->flags & ASYNC_HUP_NOTIFY)

			return -EAGAIN;

		else

			return -ERESTARTSYS;
@@ -432,7 +433,7 @@ int gs_block_til_ready(void *port_, struct file * filp) 
	 */

	if ((filp->f_flags & O_NONBLOCK) ||

	    (tty->flags & (1 << TTY_IO_ERROR))) {

		port->port.flags |= ASYNC_NORMAL_ACTIVE;

		port->flags |= ASYNC_NORMAL_ACTIVE;

		return 0;

	}
@@ -444,34 +445,34 @@ int gs_block_til_ready(void *port_, struct file * filp) 
	/*

	 * 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, port->port.count is dropped by one, so that

	 * this loop, port->count is dropped by one, so that

	 * rs_close() knows when to free things.  We restore it upon

	 * exit, either normal or abnormal.

	 */

	retval = 0;



	add_wait_queue(&port->port.open_wait, &wait);

	add_wait_queue(&port->open_wait, &wait);



	gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); 

	spin_lock_irqsave(&port->driver_lock, flags);

	spin_lock_irqsave(&gp->driver_lock, flags);

	if (!tty_hung_up_p(filp)) {

		port->port.count--;

		port->count--;

	}

	spin_unlock_irqrestore(&port->driver_lock, flags);

	port->port.blocked_open++;

	spin_unlock_irqrestore(&gp->driver_lock, flags);

	port->blocked_open++;

	while (1) {

		CD = port->rd->get_CD (port);

		CD = tty_port_carrier_raised(port);

		gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);

		set_current_state (TASK_INTERRUPTIBLE);

		if (tty_hung_up_p(filp) ||

		    !(port->port.flags & ASYNC_INITIALIZED)) {

			if (port->port.flags & ASYNC_HUP_NOTIFY)

		    !(port->flags & ASYNC_INITIALIZED)) {

			if (port->flags & ASYNC_HUP_NOTIFY)

				retval = -EAGAIN;

			else

				retval = -ERESTARTSYS;

			break;

		}

		if (!(port->port.flags & ASYNC_CLOSING) &&

		if (!(port->flags & ASYNC_CLOSING) &&

		    (do_clocal || CD))

			break;

		gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n",
@@ -483,17 +484,17 @@ int gs_block_til_ready(void *port_, struct file * filp) 
		schedule();

	}

	gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n",

		    port->port.blocked_open);

		    port->blocked_open);

	set_current_state (TASK_RUNNING);

	remove_wait_queue(&port->port.open_wait, &wait);

	remove_wait_queue(&port->open_wait, &wait);

	if (!tty_hung_up_p(filp)) {

		port->port.count++;

		port->count++;

	}

	port->port.blocked_open--;

	port->blocked_open--;

	if (retval)

		return retval;



	port->port.flags |= ASYNC_NORMAL_ACTIVE;

	port->flags |= ASYNC_NORMAL_ACTIVE;

	func_exit ();

	return 0;

}

drivers/char/isicom.c

+32 −19
Original line number Diff line number Diff line
@@ -830,20 +830,28 @@ static int isicom_setup_port(struct tty_struct *tty) 
	return 0;

}



static int isicom_carrier_raised(struct tty_port *port)

{

	struct isi_port *ip = container_of(port, struct isi_port, port);

	return (ip->status & ISI_DCD)?1 : 0;

}



static int block_til_ready(struct tty_struct *tty, struct file *filp,

	struct isi_port *port)

	struct isi_port *ip)

{

	struct isi_board *card = port->card;

	struct isi_board *card = ip->card;

	struct tty_port *port = &ip->port;

	int do_clocal = 0, retval;

	unsigned long flags;

	DECLARE_WAITQUEUE(wait, current);

	int cd;



	/* block if port is in the process of being closed */



	if (tty_hung_up_p(filp) || port->port.flags & ASYNC_CLOSING) {

	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING) {

		pr_dbg("block_til_ready: close in progress.\n");

		interruptible_sleep_on(&port->port.close_wait);

		if (port->port.flags & ASYNC_HUP_NOTIFY)

		interruptible_sleep_on(&port->close_wait);

		if (port->flags & ASYNC_HUP_NOTIFY)

			return -EAGAIN;

		else

			return -ERESTARTSYS;
@@ -854,7 +862,7 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	if ((filp->f_flags & O_NONBLOCK) ||

			(tty->flags & (1 << TTY_IO_ERROR))) {

		pr_dbg("block_til_ready: non-block mode.\n");

		port->port.flags |= ASYNC_NORMAL_ACTIVE;

		port->flags |= ASYNC_NORMAL_ACTIVE;

		return 0;

	}
@@ -864,29 +872,29 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	/* block waiting for DCD to be asserted, and while

						callout dev is busy */

	retval = 0;

	add_wait_queue(&port->port.open_wait, &wait);

	add_wait_queue(&port->open_wait, &wait);



	spin_lock_irqsave(&card->card_lock, flags);

	if (!tty_hung_up_p(filp))

		port->port.count--;

	port->port.blocked_open++;

		port->count--;

	port->blocked_open++;

	spin_unlock_irqrestore(&card->card_lock, flags);



	while (1) {

		raise_dtr_rts(port);

		raise_dtr_rts(ip);



		set_current_state(TASK_INTERRUPTIBLE);

		if (tty_hung_up_p(filp) || !(port->port.flags & ASYNC_INITIALIZED)) {

			if (port->port.flags & ASYNC_HUP_NOTIFY)

		if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)) {

			if (port->flags & ASYNC_HUP_NOTIFY)

				retval = -EAGAIN;

			else

				retval = -ERESTARTSYS;

			break;

		}

		if (!(port->port.flags & ASYNC_CLOSING) &&

				(do_clocal || (port->status & ISI_DCD))) {

		cd = tty_port_carrier_raised(port);

		if (!(port->flags & ASYNC_CLOSING) &&

				(do_clocal || cd))

			break;

		}

		if (signal_pending(current)) {

			retval = -ERESTARTSYS;

			break;
@@ -894,15 +902,15 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
		schedule();

	}

	set_current_state(TASK_RUNNING);

	remove_wait_queue(&port->port.open_wait, &wait);

	remove_wait_queue(&port->open_wait, &wait);

	spin_lock_irqsave(&card->card_lock, flags);

	if (!tty_hung_up_p(filp))

		port->port.count++;

	port->port.blocked_open--;

		port->count++;

	port->blocked_open--;

	spin_unlock_irqrestore(&card->card_lock, flags);

	if (retval)

		return retval;

	port->port.flags |= ASYNC_NORMAL_ACTIVE;

	port->flags |= ASYNC_NORMAL_ACTIVE;

	return 0;

}
@@ -1452,6 +1460,10 @@ static const struct tty_operations isicom_ops = { 
	.break_ctl		= isicom_send_break,

};



static const struct tty_port_operations isicom_port_ops = {

	.carrier_raised		= isicom_carrier_raised,

};



static int __devinit reset_card(struct pci_dev *pdev,

	const unsigned int card, unsigned int *signature)

{
@@ -1794,6 +1806,7 @@ static int __init isicom_init(void) 
		spin_lock_init(&isi_card[idx].card_lock);

		for (channel = 0; channel < 16; channel++, port++) {

			tty_port_init(&port->port);

			port->port.ops = &isicom_port_ops;

			port->magic = ISICOM_MAGIC;

			port->card = &isi_card[idx];

			port->channel = channel;

drivers/char/istallion.c

+20 −8
Original line number Diff line number Diff line
@@ -151,7 +151,7 @@ static char *stli_drvversion = "5.6.0"; 
static char	*stli_serialname = "ttyE";



static struct tty_driver	*stli_serial;



static const struct tty_port_operations stli_port_ops;



#define	STLI_TXBUFSIZE		4096
@@ -1183,6 +1183,12 @@ static int stli_setport(struct tty_struct *tty) 


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



static int stli_carrier_raised(struct tty_port *port)

{

	struct stliport *portp = container_of(port, struct stliport, port);

	return (portp->sigs & TIOCM_CD) ? 1 : 0;

}



/*

 *	Possibly need to wait for carrier (DCD signal) to come high. Say

 *	maybe because if we are clocal then we don't need to wait...
@@ -1193,6 +1199,7 @@ static int stli_waitcarrier(struct tty_struct *tty, struct stlibrd *brdp, 
{

	unsigned long flags;

	int rc, doclocal;

	struct tty_port *port = &portp->port;



	rc = 0;

	doclocal = 0;
@@ -1203,7 +1210,7 @@ static int stli_waitcarrier(struct tty_struct *tty, struct stlibrd *brdp, 
	spin_lock_irqsave(&stli_lock, flags);

	portp->openwaitcnt++;

	if (! tty_hung_up_p(filp))

		portp->port.count--;

		port->count--;

	spin_unlock_irqrestore(&stli_lock, flags);



	for (;;) {
@@ -1212,27 +1219,27 @@ static int stli_waitcarrier(struct tty_struct *tty, struct stlibrd *brdp, 
		    &portp->asig, sizeof(asysigs_t), 0)) < 0)

			break;

		if (tty_hung_up_p(filp) ||

		    ((portp->port.flags & ASYNC_INITIALIZED) == 0)) {

			if (portp->port.flags & ASYNC_HUP_NOTIFY)

		    ((port->flags & ASYNC_INITIALIZED) == 0)) {

			if (port->flags & ASYNC_HUP_NOTIFY)

				rc = -EBUSY;

			else

				rc = -ERESTARTSYS;

			break;

		}

		if (((portp->port.flags & ASYNC_CLOSING) == 0) &&

		    (doclocal || (portp->sigs & TIOCM_CD))) {

		if (((port->flags & ASYNC_CLOSING) == 0) &&

		    (doclocal || tty_port_carrier_raised(port))) {

			break;

		}

		if (signal_pending(current)) {

			rc = -ERESTARTSYS;

			break;

		}

		interruptible_sleep_on(&portp->port.open_wait);

		interruptible_sleep_on(&port->open_wait);

	}



	spin_lock_irqsave(&stli_lock, flags);

	if (! tty_hung_up_p(filp))

		portp->port.count++;

		port->count++;

	portp->openwaitcnt--;

	spin_unlock_irqrestore(&stli_lock, flags);
@@ -2696,6 +2703,7 @@ static int stli_initports(struct stlibrd *brdp) 
			continue;

		}

		tty_port_init(&portp->port);

		portp->port.ops = &stli_port_ops;

		portp->magic = STLI_PORTMAGIC;

		portp->portnr = i;

		portp->brdnr = brdp->brdnr;
@@ -4518,6 +4526,10 @@ static const struct tty_operations stli_ops = { 
	.tiocmset = stli_tiocmset,

};



static const struct tty_port_operations stli_port_ops = {

	.carrier_raised = stli_carrier_raised,

};



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

/*

 *	Loadable module initialization stuff.

drivers/char/moxa.c

+21 −5
Original line number Diff line number Diff line
@@ -206,6 +206,7 @@ static void moxa_poll(unsigned long); 
static void moxa_set_tty_param(struct tty_struct *, struct ktermios *);

static void moxa_setup_empty_event(struct tty_struct *);

static void moxa_shut_down(struct tty_struct *);

static int moxa_carrier_raised(struct tty_port *);

/*

 * moxa board interface functions:

 */
@@ -405,6 +406,10 @@ static const struct tty_operations moxa_ops = { 
	.tiocmset = moxa_tiocmset,

};



static const struct tty_port_operations moxa_port_ops = {

	.carrier_raised = moxa_carrier_raised,

};



static struct tty_driver *moxaDriver;

static DEFINE_TIMER(moxaTimer, moxa_poll, 0, 0);

static DEFINE_SPINLOCK(moxa_lock);
@@ -826,6 +831,7 @@ static int moxa_init_board(struct moxa_board_conf *brd, struct device *dev) 


	for (i = 0, p = brd->ports; i < MAX_PORTS_PER_BOARD; i++, p++) {

		tty_port_init(&p->port);

		p->port.ops = &moxa_port_ops;

		p->type = PORT_16550A;

		p->cflag = B9600 | CS8 | CREAD | CLOCAL | HUPCL;

	}
@@ -1115,15 +1121,27 @@ static void moxa_close_port(struct tty_struct *tty) 
	tty_port_tty_set(&ch->port, NULL);

}



static int moxa_carrier_raised(struct tty_port *port)

{

	struct moxa_port *ch = container_of(port, struct moxa_port, port);

	int dcd;



	spin_lock_bh(&moxa_lock);

	dcd = ch->DCDState;

	spin_unlock_bh(&moxa_lock);

	return dcd;

}



static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp,

			    struct moxa_port *ch)

{

	struct tty_port *port = &ch->port;

	DEFINE_WAIT(wait);

	int retval = 0;

	u8 dcd;



	while (1) {

		prepare_to_wait(&ch->port.open_wait, &wait, TASK_INTERRUPTIBLE);

		prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);

		if (tty_hung_up_p(filp)) {

#ifdef SERIAL_DO_RESTART

			retval = -ERESTARTSYS;
@@ -1132,9 +1150,7 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp, 
#endif

			break;

		}

		spin_lock_bh(&moxa_lock);

		dcd = ch->DCDState;

		spin_unlock_bh(&moxa_lock);

		dcd = tty_port_carrier_raised(port);

		if (dcd)

			break;
@@ -1144,7 +1160,7 @@ static int moxa_block_till_ready(struct tty_struct *tty, struct file *filp, 
		}

		schedule();

	}

	finish_wait(&ch->port.open_wait, &wait);

	finish_wait(&port->open_wait, &wait);



	return retval;

}