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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/esp.c
parentc9b3976e3fec266be25c5001a70aa0a890b6c476 (diff)
downloadop-kernel-dev-31f35939d1d9bcfb3099b32c67b896d2792603f9.zip
op-kernel-dev-31f35939d1d9bcfb3099b32c67b896d2792603f9.tar.gz
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/esp.c')
-rw-r--r--drivers/char/esp.c61
1 files changed, 37 insertions, 24 deletions
diff --git a/drivers/char/esp.c b/drivers/char/esp.c
index 7f077c0..45ec263 100644
--- a/drivers/char/esp.c
+++ b/drivers/char/esp.c
@@ -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;
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