usb: gadget: configfs: add a method to unregister the gadget

Add a method to unregister the gadget using its config_item.

There can be functions (e.g. mass storage), which in some circumstances
need the gadget stopped. Add a method of stopping the gadget.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/configfs.c

@@ -991,6 +991,14 @@ static struct configfs_subsystem gadget_subsys = {
 	.su_mutex = __MUTEX_INITIALIZER(gadget_subsys.su_mutex),
 };
 
+void unregister_gadget_item(struct config_item *item)
+{
+	struct gadget_info *gi = to_gadget_info(item);
+
+	unregister_gadget(gi);
+}
+EXPORT_SYMBOL(unregister_gadget_item);
+
 static int __init gadget_cfs_init(void)
 {
 	int ret;

drivers/usb/gadget/configfs.h

@@ -0,0 +1,6 @@
+#ifndef USB__GADGET__CONFIGFS__H
+#define USB__GADGET__CONFIGFS__H
+
+void unregister_gadget_item(struct config_item *item);
+
+#endif /*  USB__GADGET__CONFIGFS__H */