tty_port: add "tty_port_open" helper

[~andy/linux] / drivers / char / tty_port.c

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 2e8552dc5edaef207604f2b3b51a26eff898e3ca..b22a61a4fbe58c0f32a6df3cbc429655c6f2a4d9 100644 (file)
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -99,10 +99,11 @@ EXPORT_SYMBOL(tty_port_tty_set);
 
 static void tty_port_shutdown(struct tty_port *port)
 {
+       mutex_lock(&port->mutex);
        if (port->ops->shutdown &&
                test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags))
                        port->ops->shutdown(port);
-
+       mutex_unlock(&port->mutex);
 }
 
 /**
@@ -219,8 +220,11 @@ int tty_port_block_til_ready(struct tty_port *port,
 
        /* if non-blocking mode is set we can pass directly to open unless
           the port has just hung up or is in another error state */
-       if ((filp->f_flags & O_NONBLOCK) ||
-                       (tty->flags & (1 << TTY_IO_ERROR))) {
+       if (tty->flags & (1 << TTY_IO_ERROR)) {
+               port->flags |= ASYNC_NORMAL_ACTIVE;
+               return 0;
+       }
+       if (filp->f_flags & O_NONBLOCK) {
                /* Indicate we are open */
                if (tty->termios->c_cflag & CBAUD)
                        tty_port_raise_dtr_rts(port);
@@ -378,3 +382,36 @@ void tty_port_close(struct tty_port *port, struct tty_struct *tty,
        tty_port_tty_set(port, NULL);
 }
 EXPORT_SYMBOL(tty_port_close);
+
+int tty_port_open(struct tty_port *port, struct tty_struct *tty,
+                                                        struct file *filp)
+{
+       spin_lock_irq(&port->lock);
+       if (!tty_hung_up_p(filp))
+               ++port->count;
+       spin_unlock_irq(&port->lock);
+       tty_port_tty_set(port, tty);
+
+       /*
+        * Do the device-specific open only if the hardware isn't
+        * already initialized. Serialize open and shutdown using the
+        * port mutex.
+        */
+
+       mutex_lock(&port->mutex);
+
+       if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+               if (port->ops->activate) {
+                       int retval = port->ops->activate(port, tty);
+                       if (retval) {
+                               mutex_unlock(&port->mutex);
+                               return retval;
+                       }
+                }
+               set_bit(ASYNCB_INITIALIZED, &port->flags);
+       }
+       mutex_unlock(&port->mutex);
+       return tty_port_block_til_ready(port, tty, filp);
+}
+
+EXPORT_SYMBOL(tty_port_open);