From a75210a62b81ce8cfbe9e10e29880d870ce94b8d Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Thu, 24 Sep 2020 21:57:52 +0200 Subject: media: v4l: uapi: ccs: Add controls for CCS alternative analogue gain Add two new controls for alternative analogue gain some CCS compliant camera sensors support. Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- Documentation/userspace-api/media/drivers/ccs.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'Documentation/userspace-api/media') diff --git a/Documentation/userspace-api/media/drivers/ccs.rst b/Documentation/userspace-api/media/drivers/ccs.rst index a95d7941533d..ea09c8139c23 100644 --- a/Documentation/userspace-api/media/drivers/ccs.rst +++ b/Documentation/userspace-api/media/drivers/ccs.rst @@ -81,4 +81,17 @@ obtained from the following controls: The analogue gain (``x`` in the formula) is controlled through ``V4L2_CID_ANALOGUE_GAIN`` in this case. +Alternate analogue gain model +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The CCS defines another analogue gain model called alternate analogue gain. In +this case, the formula to calculate actual gain consists of linear and +exponential parts: + + gain = linear * 2 ^ exponent + +The ``linear`` and ``exponent`` factors can be set using the +``V4L2_CID_CCS_ANALOGUE_LINEAR_GAIN`` and +``V4L2_CID_CCS_ANALOGUE_EXPONENTIAL_GAIN`` controls, respectively + **Copyright** |copy| 2020 Intel Corporation -- cgit v1.2.3