USB: gadget: composite: added disconnect callback

Added a disconnect() callback to composite devices which
is called by composite glue when its disconnect callback
is called by gadget.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/composite.c

@@ -956,6 +956,8 @@ static void composite_disconnect(struct usb_gadget *gadget)
 	spin_lock_irqsave(&cdev->lock, flags);
 	if (cdev->config)
 		reset_config(cdev);
+	if (composite->disconnect)
+		composite->disconnect(cdev);
 	spin_unlock_irqrestore(&cdev->lock, flags);
 }
 

include/linux/usb/composite.h

@@ -276,6 +276,8 @@ struct usb_composite_driver {
 	int			(*bind)(struct usb_composite_dev *);
 	int			(*unbind)(struct usb_composite_dev *);
 
+	void			(*disconnect)(struct usb_composite_dev *);
+
 	/* global suspend hooks */
 	void			(*suspend)(struct usb_composite_dev *);
 	void			(*resume)(struct usb_composite_dev *);