USB: Add usb_endpoint_xfer_control to usb.h

Added a function to check if an endpoint is a control endpoint.
There were similar functions for bulk, interrupt, and isoc,
but not for control endpoints.
Signed-off-by: NSarah Bailey <saharabeara@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

include/linux/usb.h

@@ -556,6 +556,18 @@ static inline int usb_endpoint_xfer_bulk(const struct usb_endpoint_descriptor *e
 		USB_ENDPOINT_XFER_BULK);
 }
 
+/**
+ * usb_endpoint_xfer_control - check if the endpoint has control transfer type
+ * @epd: endpoint to be checked
+ *
+ * Returns true if the endpoint is of type control, otherwise it returns false.
+ */
+static inline int usb_endpoint_xfer_control(const struct usb_endpoint_descriptor *epd)
+{
+	return ((epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+		USB_ENDPOINT_XFER_CONTROL);
+}
+
 /**
  * usb_endpoint_xfer_int - check if the endpoint has interrupt transfer type
  * @epd: endpoint to be checked