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>

1 files changed, 21 insertions, 7 deletions

diff --git a/drivers/char/stallion.c b/drivers/char/stallion.c
index 963b03fb29e5..12aecdaf61ec 100644
--- a/drivers/char/stallion.c
+++ b/drivers/char/stallion.c
@@ -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                           */
 /*****************************************************************************/