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>
diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 12d327a..8b0da97 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -206,6 +206,7 @@
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 @@
.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 @@
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 @@
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 @@
#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 @@
}
schedule();
}
- finish_wait(&ch->port.open_wait, &wait);
+ finish_wait(&port->open_wait, &wait);
return retval;
}