USB: serial: add tiocmiwait subdriver operation

Add tiocmiwait operation to struct usb_serial_driver.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 12 insertions, 4 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 0b39d013c505..ada400d6594b 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -402,10 +402,17 @@ static int serial_ioctl(struct tty_struct *tty,
 
         dev_dbg(tty->dev, "%s - cmd 0x%.4x\n", __func__, cmd);
 
-        if (port->serial->type->ioctl)
-                retval = port->serial->type->ioctl(tty, cmd, arg);
-        else
-                retval = -ENOIOCTLCMD;
+        switch (cmd) {
+        case TIOCMIWAIT:
+                if (port->serial->type->tiocmiwait)
+                        retval = port->serial->type->tiocmiwait(tty, arg);
+                break;
+        default:
+                if (port->serial->type->ioctl)
+                        retval = port->serial->type->ioctl(tty, cmd, arg);
+                else
+                        retval = -ENOIOCTLCMD;
+        }
 
         return retval;
 }
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 3f8f5e3c76d5..9c8b53f80f48 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -272,6 +272,7 @@ struct usb_serial_driver {
         int  (*tiocmget)(struct tty_struct *tty);
         int  (*tiocmset)(struct tty_struct *tty,
                          unsigned int set, unsigned int clear);
+        int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
         int  (*get_icount)(struct tty_struct *tty,
                         struct serial_icounter_struct *icount);
         /* Called by the tty layer for port level work. There may or may not