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>
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

View File

@@ -130,6 +130,8 @@ static char stl_unwanted[SC26198_RXFIFOSIZE];
static DEFINE_MUTEX(stl_brdslock);
static struct stlbrd *stl_brds[STL_MAXBRDS];
static const struct tty_port_operations stl_port_ops;
/*
* Per board state flags. Used with the state field of the board struct.
* Not really much here!
@@ -786,6 +788,12 @@ static int stl_open(struct tty_struct *tty, struct file *filp)
/*****************************************************************************/
static int stl_carrier_raised(struct tty_port *port)
{
struct stlport *portp = container_of(port, struct stlport, 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...
@@ -796,6 +804,7 @@ static int stl_waitcarrier(struct tty_struct *tty, struct stlport *portp,
{
unsigned long flags;
int rc, doclocal;
struct tty_port *port = &portp->port;
pr_debug("stl_waitcarrier(portp=%p,filp=%p)\n", portp, filp);
@@ -809,32 +818,32 @@ static int stl_waitcarrier(struct tty_struct *tty, struct stlport *portp,
portp->openwaitcnt++;
if (! tty_hung_up_p(filp))
portp->port.count--;
port->count--;
for (;;) {
/* Takes brd_lock internally */
stl_setsignals(portp, 1, 1);
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;
}
/* FIXME */
interruptible_sleep_on(&portp->port.open_wait);
interruptible_sleep_on(&port->open_wait);
}
if (! tty_hung_up_p(filp))
portp->port.count++;
port->count++;
portp->openwaitcnt--;
spin_unlock_irqrestore(&stallion_lock, flags);
@@ -1776,6 +1785,7 @@ static int __devinit stl_initports(struct stlbrd *brdp, struct stlpanel *panelp)
break;
}
tty_port_init(&portp->port);
portp->port.ops = &stl_port_ops;
portp->magic = STL_PORTMAGIC;
portp->portnr = i;
portp->brdnr = panelp->brdnr;
@@ -2659,6 +2669,10 @@ static const struct tty_operations stl_ops = {
.tiocmset = stl_tiocmset,
};
static const struct tty_port_operations stl_port_ops = {
.carrier_raised = stl_carrier_raised,
};
/*****************************************************************************/
/* CD1400 HARDWARE FUNCTIONS */
/*****************************************************************************/