diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 33a7201edb61..544ddd1bdcbe 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -344,12 +344,32 @@ struct v4l2_mbus_frame_desc_entry {
 
 #define V4L2_FRAME_DESC_ENTRY_MAX	4
 
+/**
+ * enum v4l2_mbus_frame_desc_type - media bus frame description type
+ *
+ * @V4L2_MBUS_FRAME_DESC_TYPE_UNDEFINED:
+ *	Undefined frame desc type. Drivers should not use this, it is
+ *	for backwards compatibility.
+ * @V4L2_MBUS_FRAME_DESC_TYPE_PARALLEL:
+ *	Parallel media bus.
+ * @V4L2_MBUS_FRAME_DESC_TYPE_CSI2:
+ *	CSI-2 media bus. Frame desc parameters must be set in
+ *	&struct v4l2_mbus_frame_desc_entry->csi2.
+ */
+enum v4l2_mbus_frame_desc_type {
+	V4L2_MBUS_FRAME_DESC_TYPE_UNDEFINED = 0,
+	V4L2_MBUS_FRAME_DESC_TYPE_PARALLEL,
+	V4L2_MBUS_FRAME_DESC_TYPE_CSI2,
+};
+
 /**
  * struct v4l2_mbus_frame_desc - media bus data frame description
+ * @type: type of the bus (enum v4l2_mbus_frame_desc_type)
  * @entry: frame descriptors array
  * @num_entries: number of entries in @entry array
  */
 struct v4l2_mbus_frame_desc {
+	enum v4l2_mbus_frame_desc_type type;
 	struct v4l2_mbus_frame_desc_entry entry[V4L2_FRAME_DESC_ENTRY_MAX];
 	unsigned short num_entries;
 };