[media] v4l: subdev: Generic ioctl support

Instead of returning an error when receiving an ioctl call with an
unsupported command, forward the call to the subdev core::ioctl handler.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index 77d96f4..f2df31b 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -405,6 +405,11 @@
 	To properly support events, the poll() file operation is also
 	implemented.
 
+Private ioctls
+
+	All ioctls not in the above list are passed directly to the sub-device
+	driver through the core::ioctl operation.
+
 
 I2C sub-device drivers
 ----------------------
diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
index 6e76f73..0b80644 100644
--- a/drivers/media/video/v4l2-subdev.c
+++ b/drivers/media/video/v4l2-subdev.c
@@ -276,7 +276,7 @@
 	}
 #endif
 	default:
-		return -ENOIOCTLCMD;
+		return v4l2_subdev_call(sd, core, ioctl, cmd, arg);
 	}
 
 	return 0;