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tty_port: Add a port level carrier detect operation

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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>
This commit is contained in:
Alan Cox
2009-01-02 13:45:05 +00:00
committed by Linus Torvalds
parent c9b3976e3f
commit 31f35939d1
19 changed files with 428 additions and 240 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/char/riscom8.c
+40 -25
View File
@@ -857,23 +857,40 @@ static void rc_shutdown_port(struct tty_struct *tty,
rc_shutdown_board(bp);
}
static int carrier_raised(struct tty_port *port)
{
struct riscom_port *p = container_of(port, struct riscom_port, port);
struct riscom_board *bp = port_Board(p);
unsigned long flags;
int CD;
spin_lock_irqsave(&riscom_lock, flags);
rc_out(bp, CD180_CAR, port_No(p));
CD = rc_in(bp, CD180_MSVR) & MSVR_CD;
rc_out(bp, CD180_MSVR, MSVR_RTS);
bp->DTR &= ~(1u << port_No(p));
rc_out(bp, RC_DTR, bp->DTR);
spin_unlock_irqrestore(&riscom_lock, flags);
return CD;
}
static int block_til_ready(struct tty_struct *tty, struct file *filp,
struct riscom_port *port)
struct riscom_port *rp)
{
DECLARE_WAITQUEUE(wait, current);
struct riscom_board *bp = port_Board(port);
int retval;
int do_clocal = 0;
int CD;
unsigned long flags;
struct tty_port *port = &rp->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) || 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;
@@ -885,7 +902,7 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
*/
if ((filp->f_flags & O_NONBLOCK) ||
(tty->flags & (1 << TTY_IO_ERROR))) {
port->port.flags |= ASYNC_NORMAL_ACTIVE;
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
@@ -900,37 +917,29 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
* exit, either normal or abnormal.
*/
retval = 0;
add_wait_queue(&port->port.open_wait, &wait);
add_wait_queue(&port->open_wait, &wait);
spin_lock_irqsave(&riscom_lock, flags);
if (!tty_hung_up_p(filp))
port->port.count--;
port->count--;
spin_unlock_irqrestore(&riscom_lock, flags);
port->port.blocked_open++;
port->blocked_open++;
while (1) {
spin_lock_irqsave(&riscom_lock, flags);
rc_out(bp, CD180_CAR, port_No(port));
CD = rc_in(bp, CD180_MSVR) & MSVR_CD;
rc_out(bp, CD180_MSVR, MSVR_RTS);
bp->DTR &= ~(1u << port_No(port));
rc_out(bp, RC_DTR, bp->DTR);
spin_unlock_irqrestore(&riscom_lock, flags);
CD = tty_port_carrier_raised(port);
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;
if (signal_pending(current)) {
@@ -940,14 +949,14 @@ 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);
if (!tty_hung_up_p(filp))
port->port.count++;
port->port.blocked_open--;
port->count++;
port->blocked_open--;
if (retval)
return retval;
port->port.flags |= ASYNC_NORMAL_ACTIVE;
port->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
@@ -1510,6 +1519,11 @@ static const struct tty_operations riscom_ops = {
.break_ctl = rc_send_break,
};
static const struct tty_port_operations riscom_port_ops = {
.carrier_raised = carrier_raised,
};
static int __init rc_init_drivers(void)
{
int error;
@@ -1541,6 +1555,7 @@ static int __init rc_init_drivers(void)
memset(rc_port, 0, sizeof(rc_port));
for (i = 0; i < RC_NPORT * RC_NBOARD; i++) {
tty_port_init(&rc_port[i].port);
rc_port[i].port.ops = &riscom_port_ops;
rc_port[i].magic = RISCOM8_MAGIC;
}
return 0;