diff --git a/drivers/staging/greybus/greybus_protocols.h b/drivers/staging/greybus/greybus_protocols.h
index 290b85f6ff68..b95d24bd8e62 100644
--- a/drivers/staging/greybus/greybus_protocols.h
+++ b/drivers/staging/greybus/greybus_protocols.h
@@ -99,6 +99,10 @@ struct gb_operation_msg_hdr {
 };
 
 
+/* Generic request numbers supported by all modules */
+#define GB_REQUEST_TYPE_INVALID			0x00
+#define GB_REQUEST_TYPE_PROTOCOL_VERSION	0x01
+
 /* Control Protocol */
 
 /* version request has no payload */