USB: suspend support for usb serial

this implements generic support for suspend/resume for usb serial.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 87f3788..e3e3728 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -46,6 +46,8 @@
 	.name =		"usbserial",
 	.probe =	usb_serial_probe,
 	.disconnect =	usb_serial_disconnect,
+	.suspend =	usb_serial_suspend,
+	.resume =	usb_serial_resume,
 	.no_dynamic_id = 	1,
 };
 
@@ -1069,6 +1071,35 @@
 	dev_info(dev, "device disconnected\n");
 }
 
+int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct usb_serial *serial = usb_get_intfdata(intf);
+	struct usb_serial_port *port;
+	int i, r = 0;
+
+	if (serial) {
+		for (i = 0; i < serial->num_ports; ++i) {
+			port = serial->port[i];
+			if (port)
+				kill_traffic(port);
+		}
+	}
+
+	if (serial->type->suspend)
+		serial->type->suspend(serial, message);
+
+	return r;
+}
+EXPORT_SYMBOL(usb_serial_suspend);
+
+int usb_serial_resume(struct usb_interface *intf)
+{
+	struct usb_serial *serial = usb_get_intfdata(intf);
+
+	return serial->type->resume(serial);
+}
+EXPORT_SYMBOL(usb_serial_resume);
+
 static const struct tty_operations serial_ops = {
 	.open =			serial_open,
 	.close =		serial_close,