usb: interface authorization: Introduces the USB interface authorization

The kernel supports the device authorization because of wireless USB.
These is usable for wired USB devices, too.
These new interface authorization allows to enable or disable
individual interfaces instead a whole device.

If a deauthorized interface will be authorized so the driver probing must
be triggered manually by writing INTERFACE to /sys/bus/usb/drivers_probe

Signed-off-by: Stefan Koch <stefan.koch10@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 3d25d89..c090f50 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1555,6 +1555,44 @@
 	kfree(intf);
 }
 
+/*
+ * usb_deauthorize_interface - deauthorize an USB interface
+ *
+ * @intf: USB interface structure
+ */
+void usb_deauthorize_interface(struct usb_interface *intf)
+{
+	struct device *dev = &intf->dev;
+
+	device_lock(dev->parent);
+
+	if (intf->authorized) {
+		device_lock(dev);
+		intf->authorized = 0;
+		device_unlock(dev);
+
+		usb_forced_unbind_intf(intf);
+	}
+
+	device_unlock(dev->parent);
+}
+
+/*
+ * usb_authorize_interface - authorize an USB interface
+ *
+ * @intf: USB interface structure
+ */
+void usb_authorize_interface(struct usb_interface *intf)
+{
+	struct device *dev = &intf->dev;
+
+	if (!intf->authorized) {
+		device_lock(dev);
+		intf->authorized = 1; /* authorize interface */
+		device_unlock(dev);
+	}
+}
+
 static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct usb_device *usb_dev;