From 1dd8728e2147820f653e5ea92802002fb26131f1 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Thu, 10 May 2012 05:04:41 -0300 Subject: [PATCH] [media] v4l2-framework.txt: document v4l2_dont_use_cmd Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/video4linux/v4l2-framework.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index e1e6a01..0dace87 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -619,6 +619,16 @@ in your v4l2_file_operations struct. Do not use .ioctl! This is deprecated and will go away in the future. +In some cases you want to tell the core that a function you had specified in +your v4l2_ioctl_ops should be ignored. You can mark such ioctls by calling this +function before video_device_register is called: + +void v4l2_dont_use_cmd(struct video_device *vdev, unsigned int cmd); + +This tends to be needed if based on external factors (e.g. which card is +being used) you want to turns off certain features in v4l2_ioctl_ops without +having to make a new struct. + The v4l2_file_operations struct is a subset of file_operations. The main difference is that the inode argument is omitted since it is never used. -- 2.7.4