Commit a75210a6 authored by Sakari Ailus's avatar Sakari Ailus Committed by Mauro Carvalho Chehab
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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: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent ee25e211

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

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@@ -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

include/uapi/linux/ccs.h

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@@ -10,5 +10,7 @@ 
#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)

#define V4L2_CID_CCS_ANALOGUE_LINEAR_GAIN	(V4L2_CID_USER_CCS_BASE + 5)

#define V4L2_CID_CCS_ANALOGUE_EXPONENTIAL_GAIN	(V4L2_CID_USER_CCS_BASE + 6)



#endif