From 371f94490ea97e1bf766ba0d33ffb62f5f5a4ed1 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Fri, 9 Jun 2017 10:15:50 -0300 Subject: [PATCH] [media] v4l: controls: Improve documentation for V4L2_CID_GAIN Elaborate the differences between V4L2_CID_GAIN and gain-type specific V4L2_CID_DIGITAL_GAIN and V4L2_CID_ANALOGUE_GAIN. Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/media/uapi/v4l/control.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/media/uapi/v4l/control.rst b/Documentation/media/uapi/v4l/control.rst index 51112badb804..c1e6adbe83d7 100644 --- a/Documentation/media/uapi/v4l/control.rst +++ b/Documentation/media/uapi/v4l/control.rst @@ -137,6 +137,12 @@ Control IDs ``V4L2_CID_GAIN`` ``(integer)`` Gain control. + Primarily used to control gain on e.g. TV tuners but also on + webcams. Most devices control only digital gain with this control + but on some this could include analogue gain as well. Devices that + recognise the difference between digital and analogue gain use + controls ``V4L2_CID_DIGITAL_GAIN`` and ``V4L2_CID_ANALOGUE_GAIN``. + ``V4L2_CID_HFLIP`` ``(boolean)`` Mirror the picture horizontally. -- 2.20.1