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, 22 insertions, 21 deletions

diff --git a/drivers/char/generic_serial.c b/drivers/char/generic_serial.c
index c6090f84a2e4..2356994ee010 100644
--- a/drivers/char/generic_serial.c
+++ b/drivers/char/generic_serial.c
@@ -397,7 +397,8 @@ void gs_hangup(struct tty_struct *tty)
 
 int gs_block_til_ready(void *port_, struct file * filp)
 {
-        struct gs_port *port = port_;
+        struct gs_port *gp = port_;
+        struct tty_port *port = &gp->port;
         DECLARE_WAITQUEUE(wait, current);
         int    retval;
         int    do_clocal = 0;
@@ -409,16 +410,16 @@ int gs_block_til_ready(void *port_, struct file * filp)
 
         if (!port) return 0;
 
-        tty = port->port.tty;
+        tty = port->tty;
 
         gs_dprintk (GS_DEBUG_BTR, "Entering gs_block_till_ready.\n"); 
         /*
          * 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;
@@ -432,7 +433,7 @@ int gs_block_til_ready(void *port_, 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;
         }
 
@@ -444,34 +445,34 @@ int gs_block_til_ready(void *port_, 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, port->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(&port->port.open_wait, &wait);
+        add_wait_queue(&port->open_wait, &wait);
 
         gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); 
-        spin_lock_irqsave(&port->driver_lock, flags);
+        spin_lock_irqsave(&gp->driver_lock, flags);
         if (!tty_hung_up_p(filp)) {
-                port->port.count--;
+                port->count--;
         }
-        spin_unlock_irqrestore(&port->driver_lock, flags);
-        port->port.blocked_open++;
+        spin_unlock_irqrestore(&gp->driver_lock, flags);
+        port->blocked_open++;
         while (1) {
-                CD = port->rd->get_CD (port);
+                CD = tty_port_carrier_raised(port);
                 gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);
                 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;
                 gs_dprintk (GS_DEBUG_BTR, "signal_pending is now: %d (%lx)\n", 
@@ -483,17 +484,17 @@ int gs_block_til_ready(void *port_, struct file * filp)
                 schedule();
         }
         gs_dprintk (GS_DEBUG_BTR, "Got out of the loop. (%d)\n",
-                    port->port.blocked_open);
+                    port->blocked_open);
         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->count++;
         }
-        port->port.blocked_open--;
+        port->blocked_open--;
         if (retval)
                 return retval;
 
-        port->port.flags |= ASYNC_NORMAL_ACTIVE;
+        port->flags |= ASYNC_NORMAL_ACTIVE;
         func_exit ();
         return 0;
 }