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authorAlan Cox <alan@redhat.com>2009-01-02 13:45:05 +0000
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-02 10:19:38 -0800
commit31f35939d1d9bcfb3099b32c67b896d2792603f9 (patch)
tree39b6ceaf0e7477e0357ff8235814f579adad3f28 /drivers/char/synclink.c
parentc9b3976e3fec266be25c5001a70aa0a890b6c476 (diff)
downloadlinux-31f35939d1d9bcfb3099b32c67b896d2792603f9.tar.bz2
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: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char/synclink.c')
-rw-r--r--drivers/char/synclink.c61
1 files changed, 41 insertions, 20 deletions
diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
index 500f5176b6ba..fb2e6b5e0ef1 100644
--- a/drivers/char/synclink.c
+++ b/drivers/char/synclink.c
@@ -3281,6 +3281,23 @@ static void mgsl_hangup(struct tty_struct *tty)
} /* end of mgsl_hangup() */
+/*
+ * carrier_raised()
+ *
+ * Return true if carrier is raised
+ */
+
+static int carrier_raised(struct tty_port *port)
+{
+ unsigned long flags;
+ struct mgsl_struct *info = container_of(port, struct mgsl_struct, port);
+
+ spin_lock_irqsave(&info->irq_spinlock, flags);
+ usc_get_serial_signals(info);
+ spin_unlock_irqrestore(&info->irq_spinlock, flags);
+ return (info->serial_signals & SerialSignal_DCD) ? 1 : 0;
+}
+
/* block_til_ready()
*
* Block the current process until the specified port
@@ -3302,6 +3319,8 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
bool do_clocal = false;
bool extra_count = false;
unsigned long flags;
+ int dcd;
+ struct tty_port *port = &info->port;
if (debug_level >= DEBUG_LEVEL_INFO)
printk("%s(%d):block_til_ready on %s\n",
@@ -3309,7 +3328,7 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
if (filp->f_flags & O_NONBLOCK || tty->flags & (1 << TTY_IO_ERROR)){
/* nonblock mode is set or port is not enabled */
- info->port.flags |= ASYNC_NORMAL_ACTIVE;
+ port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
@@ -3318,25 +3337,25 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
/* Wait for 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
* mgsl_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);
if (debug_level >= DEBUG_LEVEL_INFO)
printk("%s(%d):block_til_ready before block on %s count=%d\n",
- __FILE__,__LINE__, tty->driver->name, info->port.count );
+ __FILE__,__LINE__, tty->driver->name, port->count );
spin_lock_irqsave(&info->irq_spinlock, flags);
if (!tty_hung_up_p(filp)) {
extra_count = true;
- info->port.count--;
+ port->count--;
}
spin_unlock_irqrestore(&info->irq_spinlock, flags);
- info->port.blocked_open++;
+ port->blocked_open++;
while (1) {
if (tty->termios->c_cflag & CBAUD) {
@@ -3348,20 +3367,16 @@ 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)){
- retval = (info->port.flags & ASYNC_HUP_NOTIFY) ?
+ if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)){
+ retval = (port->flags & ASYNC_HUP_NOTIFY) ?
-EAGAIN : -ERESTARTSYS;
break;
}
- spin_lock_irqsave(&info->irq_spinlock,flags);
- usc_get_serial_signals(info);
- spin_unlock_irqrestore(&info->irq_spinlock,flags);
+ dcd = tty_port_carrier_raised(&info->port);
- if (!(info->port.flags & ASYNC_CLOSING) &&
- (do_clocal || (info->serial_signals & SerialSignal_DCD)) ) {
+ if (!(port->flags & ASYNC_CLOSING) && (do_clocal || dcd))
break;
- }
if (signal_pending(current)) {
retval = -ERESTARTSYS;
@@ -3370,24 +3385,24 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
if (debug_level >= DEBUG_LEVEL_INFO)
printk("%s(%d):block_til_ready blocking on %s count=%d\n",
- __FILE__,__LINE__, tty->driver->name, info->port.count );
+ __FILE__,__LINE__, tty->driver->name, port->count );
schedule();
}
set_current_state(TASK_RUNNING);
- remove_wait_queue(&info->port.open_wait, &wait);
+ remove_wait_queue(&port->open_wait, &wait);
if (extra_count)
- info->port.count++;
- info->port.blocked_open--;
+ port->count++;
+ port->blocked_open--;
if (debug_level >= DEBUG_LEVEL_INFO)
printk("%s(%d):block_til_ready after blocking on %s count=%d\n",
- __FILE__,__LINE__, tty->driver->name, info->port.count );
+ __FILE__,__LINE__, tty->driver->name, port->count );
if (!retval)
- info->port.flags |= ASYNC_NORMAL_ACTIVE;
+ port->flags |= ASYNC_NORMAL_ACTIVE;
return retval;
@@ -4304,6 +4319,11 @@ static void mgsl_add_device( struct mgsl_struct *info )
} /* end of mgsl_add_device() */
+static const struct tty_port_operations mgsl_port_ops = {
+ .carrier_raised = carrier_raised,
+};
+
+
/* mgsl_allocate_device()
*
* Allocate and initialize a device instance structure
@@ -4322,6 +4342,7 @@ static struct mgsl_struct* mgsl_allocate_device(void)
printk("Error can't allocate device instance data\n");
} else {
tty_port_init(&info->port);
+ info->port.ops = &mgsl_port_ops;
info->magic = MGSL_MAGIC;
INIT_WORK(&info->task, mgsl_bh_handler);
info->max_frame_size = 4096;