Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Documentation: media: mali-c55: Document the mali-c55 parameter setting
Document the mali-c55 parameter setting by expanding the relevant
pages in both admin-guide/ and userspace-api/.
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Nayden Kanchev <nayden.kanchev@arm.com>
Co-developed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
authored by
Daniel Scally
and committed by
Hans Verkuil
87b214dd
01535ea0
+75
-5
+17
-2
Documentation/admin-guide/media/mali-c55.rst
+17
-2
Documentation/admin-guide/media/mali-c55.rst
···
387
387
+-------------+ | +-------------+
388
388
+--> AWB-1
389
389
390
-
At present all statistics are drawn from the 0th tap point for each algorithm;
390
+
By default all statistics are drawn from the 0th tap point for each algorithm;
391
391
I.E. AEXP statistics from AEXP-0 (A), AWB statistics from AWB-0 and AF
392
-
statistics from AF-0. In the future this will be configurable.
392
+
statistics from AF-0. This is configurable for AEXP and AWB statsistics through
393
+
programming the ISP's parameters.
394
+
395
+
.. _mali-c55-3a-params:
396
+
397
+
Programming ISP Parameters
398
+
==========================
399
+
400
+
The ISP can be programmed with various parameters from userspace to apply to the
401
+
hardware before and during video stream. This allows userspace to dynamically
402
+
change values such as black level, white balance and lens shading gains and so
403
+
on.
404
+
405
+
The buffer format and how to populate it are described by the
406
+
:ref:`V4L2_META_FMT_MALI_C55_PARAMS <v4l2-meta-fmt-mali-c55-params>` format,
407
+
which should be set as the data format for the `mali-c55 3a params` video node.
393
408
394
409
References
395
410
==========
+58
-3
Documentation/userspace-api/media/v4l/metafmt-arm-mali-c55.rst
+58
-3
Documentation/userspace-api/media/v4l/metafmt-arm-mali-c55.rst
···
1
1
.. SPDX-License-Identifier: GPL-2.0
2
2
3
+
.. _v4l2-meta-fmt-mali-c55-params:
3
4
.. _v4l2-meta-fmt-mali-c55-stats:
4
5
5
-
*************************************
6
-
V4L2_META_FMT_MALI_C55_STATS ('C55S')
7
-
*************************************
6
+
*****************************************************************************
7
+
V4L2_META_FMT_MALI_C55_STATS ('C55S'), V4L2_META_FMT_MALI_C55_PARAMS ('C55P')
8
+
*****************************************************************************
8
9
9
10
3A Statistics
10
11
=============
···
23
22
(struct mali_c55_stats_buffer *)buf;
24
23
25
24
For details of the statistics see :c:type:`mali_c55_stats_buffer`.
25
+
26
+
Configuration Parameters
27
+
========================
28
+
29
+
The configuration parameters are passed to the :ref:`mali-c55 3a params
30
+
<mali-c55-3a-params>` metadata output video node, using the
31
+
:c:type:`v4l2_meta_format` interface. Rather than a single struct containing
32
+
sub-structs for each configurable area of the ISP, parameters for the Mali-C55
33
+
use the v4l2-isp parameters system, through which groups of parameters are
34
+
defined as distinct structs or "blocks" which may be added to the data member of
35
+
:c:type:`v4l2_isp_params_buffer`. Userspace is responsible for populating the
36
+
data member with the blocks that need to be configured by the driver. Each
37
+
block-specific struct embeds :c:type:`v4l2_isp_params_block_header` as its first
38
+
member and userspace must populate the type member with a value from
39
+
:c:type:`mali_c55_param_block_type`.
40
+
41
+
.. code-block:: c
42
+
43
+
struct v4l2_isp_params_buffer *params =
44
+
(struct v4l2_isp_params_buffer *)buffer;
45
+
46
+
params->version = MALI_C55_PARAM_BUFFER_V1;
47
+
params->data_size = 0;
48
+
49
+
void *data = (void *)params->data;
50
+
51
+
struct mali_c55_params_awb_gains *gains =
52
+
(struct mali_c55_params_awb_gains *)data;
53
+
54
+
gains->header.type = MALI_C55_PARAM_BLOCK_AWB_GAINS;
55
+
gains->header.flags |= V4L2_ISP_PARAMS_FL_BLOCK_ENABLE;
56
+
gains->header.size = sizeof(struct mali_c55_params_awb_gains);
57
+
58
+
gains->gain00 = 256;
59
+
gains->gain00 = 256;
60
+
gains->gain00 = 256;
61
+
gains->gain00 = 256;
62
+
63
+
data += sizeof(struct mali_c55_params_awb_gains);
64
+
params->data_size += sizeof(struct mali_c55_params_awb_gains);
65
+
66
+
struct mali_c55_params_sensor_off_preshading *blc =
67
+
(struct mali_c55_params_sensor_off_preshading *)data;
68
+
69
+
blc->header.type = MALI_C55_PARAM_BLOCK_SENSOR_OFFS;
70
+
blc->header.flags |= V4L2_ISP_PARAMS_FL_BLOCK_ENABLE;
71
+
blc->header.size = sizeof(struct mali_c55_params_sensor_off_preshading);
72
+
73
+
blc->chan00 = 51200;
74
+
blc->chan01 = 51200;
75
+
blc->chan10 = 51200;
76
+
blc->chan11 = 51200;
77
+
78
+
params->data_size += sizeof(struct mali_c55_params_sensor_off_preshading);
26
79
27
80
Arm Mali-C55 uAPI data types
28
81
============================