Commit a8a2d75b authored by Sakari Ailus's avatar Sakari Ailus Committed by Mauro Carvalho Chehab
Browse files

media: v4l: uapi: ccs: Add controls for analogue gain constants 



Add V4L2 controls for analogue gain constants required to control
analogue gain. The values are device specific and thus need to be obtained
from the driver.

Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent db08f69e

Documentation/userspace-api/media/drivers/ccs.rst

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@@ -56,4 +56,29 @@ analogue data is never read from the pixel matrix that are outside the 
configured selection rectangle that designates crop. The difference has an

effect in device timing and likely also in power consumption.



Private controls

----------------



The MIPI CCS driver implements a number of private controls under

``V4L2_CID_USER_BASE_CCS`` to control the MIPI CCS compliant camera sensors.



Analogue gain model

~~~~~~~~~~~~~~~~~~~



The CCS defines an analogue gain model where the gain can be calculated using

the following formula:



	gain = m0 * x + c0 / (m1 * x + c1)



Either m0 or c0 will be zero. The constants that are device specific, can be

obtained from the following controls:



	V4L2_CID_CCS_ANALOGUE_GAIN_M0

	V4L2_CID_CCS_ANALOGUE_GAIN_M1

	V4L2_CID_CCS_ANALOGUE_GAIN_C0

	V4L2_CID_CCS_ANALOGUE_GAIN_C1



The analogue gain (``x`` in the formula) is controlled through

``V4L2_CID_ANALOGUE_GAIN`` in this case.



**Copyright** |copy| 2020 Intel Corporation

MAINTAINERS

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@@ -11840,6 +11840,7 @@ F: Documentation/userspace-api/media/drivers/ccs.rst 
F:	drivers/media/i2c/ccs-pll.c

F:	drivers/media/i2c/ccs-pll.h

F:	drivers/media/i2c/ccs/

F:	include/uapi/linux/ccs.h

F:	include/uapi/linux/smiapp.h









MIPS
































include/uapi/linux/ccs.h
0 → 100644



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/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */









/* Copyright (C) 2020 Intel Corporation */



















#ifndef __UAPI_CCS_H__









#define __UAPI_CCS_H__



















#include <linux/v4l2-controls.h>



















#define V4L2_CID_CCS_ANALOGUE_GAIN_M0		(V4L2_CID_USER_CCS_BASE + 1)









#define V4L2_CID_CCS_ANALOGUE_GAIN_C0		(V4L2_CID_USER_CCS_BASE + 2)









#define V4L2_CID_CCS_ANALOGUE_GAIN_M1		(V4L2_CID_USER_CCS_BASE + 3)









#define V4L2_CID_CCS_ANALOGUE_GAIN_C1		(V4L2_CID_USER_CCS_BASE + 4)



















#endif