usb: gadget: Add gadget_is_superspeed_plus()

Add a function to check for SuperSpeedPlus capable gadgets.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index d82d006..d6a1bda 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -729,6 +729,16 @@
 }
 
 /**
+ * gadget_is_superspeed_plus() - return true if the hardware handles
+ *	superspeed plus
+ * @g: controller that might support superspeed plus
+ */
+static inline int gadget_is_superspeed_plus(struct usb_gadget *g)
+{
+	return g->max_speed >= USB_SPEED_SUPER_PLUS;
+}
+
+/**
  * gadget_is_otg - return true iff the hardware is OTG-ready
  * @g: controller that might have a Mini-AB connector
  *