media: uvcvideo: Allow extra entities

Increase the size of the id, to avoid collisions with entities
implemented by the driver that are not part of the UVC device.

Entities exposed by the UVC device use IDs 0-255, extra entities
implemented by the driver (such as the GPIO entity) use IDs 256 and
up.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/usb/uvc/uvc_driver.c

@@ -1024,7 +1024,7 @@ static const u8 uvc_media_transport_input_guid[16] =
 	UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT;
 static const u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;
 
-static struct uvc_entity *uvc_alloc_entity(u16 type, u8 id,
+static struct uvc_entity *uvc_alloc_entity(u16 type, u16 id,
 		unsigned int num_pads, unsigned int extra_size)
 {
 	struct uvc_entity *entity;

drivers/media/usb/uvc/uvcvideo.h

@@ -301,7 +301,12 @@ struct uvc_entity {
 					 * chain. */
 	unsigned int flags;
 
-	u8 id;
+	/*
+	 * Entities exposed by the UVC device use IDs 0-255, extra entities
+	 * implemented by the driver (such as the GPIO entity) use IDs 256 and
+	 * up.
+	 */
+	u16 id;
 	u16 type;
 	char name[64];
 	u8 guid[16];