media: uvcvideo: Use control names from framework

The framework already contains a map of IDs to names, lets use it when
possible.
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Suggested-by: Hans Verkuil <hverkuil@xs4all.nl>
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_v4l2.c

@@ -40,7 +40,13 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
 		return -ENOMEM;
 
 	map->id = xmap->id;
-	memcpy(map->name, xmap->name, sizeof(map->name));
+	/* Non standard control id. */
+	if (v4l2_ctrl_get_name(map->id) == NULL) {
+		map->name = kmemdup(xmap->name, sizeof(xmap->name),
+				    GFP_KERNEL);
+		if (!map->name)
+			return -ENOMEM;
+	}
 	memcpy(map->entity, xmap->entity, sizeof(map->entity));
 	map->selector = xmap->selector;
 	map->size = xmap->size;

drivers/media/usb/uvc/uvcvideo.h

@@ -241,7 +241,7 @@ struct uvc_control_mapping {
 	struct list_head ev_subs;
 
 	u32 id;
-	u8 name[32];
+	char *name;
 	u8 entity[16];
 	u8 selector;