usb: gadget: epautoconf: add usb_ep_autoconfig_release() function

This patch introduces usb_ep_autoconfig_release() function which allows
to release endpoint previously obtained from usb_ep_autoconfig() during
USB function bind.

Signed-off-by: Robert Baldyga <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/gadget/epautoconf.c

···
 EXPORT_SYMBOL_GPL(usb_ep_autoconfig);
 
 /**
+ * usb_ep_autoconfig_release - releases endpoint and set it to initial state
+ * @ep: endpoint which should be released
+ *
+ * This function can be used during function bind for endpoints obtained
+ * from usb_ep_autoconfig(). It unclaims endpoint claimed by
+ * usb_ep_autoconfig() to make it available for other functions. Endpoint
+ * which was released is no longer invalid and shouldn't be used in
+ * context of function which released it.
+ */
+void usb_ep_autoconfig_release(struct usb_ep *ep)
+{
+	ep->claimed = false;
+	ep->driver_data = NULL;
+}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_release);
+
+/**
  * usb_ep_autoconfig_reset - reset endpoint autoconfig state
  * @gadget: device for which autoconfig state will be reset
  *

include/linux/usb/gadget.h

···
 			struct usb_endpoint_descriptor *,
 			struct usb_ss_ep_comp_descriptor *);
 
+extern void usb_ep_autoconfig_release(struct usb_ep *);
+
 extern void usb_ep_autoconfig_reset(struct usb_gadget *);
 
 #endif /* __LINUX_USB_GADGET_H */