On Tue Nov 11 16:15:59 2025 +0000, Daniel Scally wrote:
> Document the mali-c55 parameter setting by expanding the relevant
> pages in both admin-guide/ and userspace-api/.
>
> Tested-by: Lad Prabhakar <[email protected]>
> Reviewed-by: Laurent Pinchart <[email protected]>
> Acked-by: Nayden Kanchev <[email protected]>
> Co-developed-by: Jacopo Mondi <[email protected]>
> Signed-off-by: Jacopo Mondi <[email protected]>
> Signed-off-by: Daniel Scally <[email protected]>
> Signed-off-by: Hans Verkuil <[email protected]>
Patch committed.
Thanks,
Hans Verkuil
Documentation/admin-guide/media/mali-c55.rst | 19 ++++++-
.../media/v4l/metafmt-arm-mali-c55.rst | 61 ++++++++++++++++++++--
2 files changed, 75 insertions(+), 5 deletions(-)
---
diff --git a/Documentation/admin-guide/media/mali-c55.rst
b/Documentation/admin-guide/media/mali-c55.rst
index 03723e0e8e43..315f982000c4 100644
--- a/Documentation/admin-guide/media/mali-c55.rst
+++ b/Documentation/admin-guide/media/mali-c55.rst
@@ -387,9 +387,24 @@ the processing flow the statistics can be drawn from::
+-------------+ | +-------------+
+--> AWB-1
-At present all statistics are drawn from the 0th tap point for each algorithm;
+By default all statistics are drawn from the 0th tap point for each algorithm;
I.E. AEXP statistics from AEXP-0 (A), AWB statistics from AWB-0 and AF
-statistics from AF-0. In the future this will be configurable.
+statistics from AF-0. This is configurable for AEXP and AWB statsistics through
+programming the ISP's parameters.
+
+.. _mali-c55-3a-params:
+
+Programming ISP Parameters
+==========================
+
+The ISP can be programmed with various parameters from userspace to apply to
the
+hardware before and during video stream. This allows userspace to dynamically
+change values such as black level, white balance and lens shading gains and so
+on.
+
+The buffer format and how to populate it are described by the
+:ref:`V4L2_META_FMT_MALI_C55_PARAMS <v4l2-meta-fmt-mali-c55-params>` format,
+which should be set as the data format for the `mali-c55 3a params` video node.
References
==========
diff --git a/Documentation/userspace-api/media/v4l/metafmt-arm-mali-c55.rst
b/Documentation/userspace-api/media/v4l/metafmt-arm-mali-c55.rst
index 0bda9740a6be..696e0a645a7e 100644
--- a/Documentation/userspace-api/media/v4l/metafmt-arm-mali-c55.rst
+++ b/Documentation/userspace-api/media/v4l/metafmt-arm-mali-c55.rst
@@ -1,10 +1,11 @@
.. SPDX-License-Identifier: GPL-2.0
+.. _v4l2-meta-fmt-mali-c55-params:
.. _v4l2-meta-fmt-mali-c55-stats:
-*************************************
-V4L2_META_FMT_MALI_C55_STATS ('C55S')
-*************************************
+*****************************************************************************
+V4L2_META_FMT_MALI_C55_STATS ('C55S'), V4L2_META_FMT_MALI_C55_PARAMS ('C55P')
+*****************************************************************************
3A Statistics
=============
@@ -23,6 +24,60 @@ of the C structure :c:type:`mali_c55_stats_buffer` defined in
For details of the statistics see :c:type:`mali_c55_stats_buffer`.
+Configuration Parameters
+========================
+
+The configuration parameters are passed to the :ref:`mali-c55 3a params
+<mali-c55-3a-params>` metadata output video node, using the
+:c:type:`v4l2_meta_format` interface. Rather than a single struct containing
+sub-structs for each configurable area of the ISP, parameters for the Mali-C55
+use the v4l2-isp parameters system, through which groups of parameters are
+defined as distinct structs or "blocks" which may be added to the data member
of
+:c:type:`v4l2_isp_params_buffer`. Userspace is responsible for populating the
+data member with the blocks that need to be configured by the driver. Each
+block-specific struct embeds :c:type:`v4l2_isp_params_block_header` as its
first
+member and userspace must populate the type member with a value from
+:c:type:`mali_c55_param_block_type`.
+
+.. code-block:: c
+
+ struct v4l2_isp_params_buffer *params =
+ (struct v4l2_isp_params_buffer *)buffer;
+
+ params->version = MALI_C55_PARAM_BUFFER_V1;
+ params->data_size = 0;
+
+ void *data = (void *)params->data;
+
+ struct mali_c55_params_awb_gains *gains =
+ (struct mali_c55_params_awb_gains *)data;
+
+ gains->header.type = MALI_C55_PARAM_BLOCK_AWB_GAINS;
+ gains->header.flags |= V4L2_ISP_PARAMS_FL_BLOCK_ENABLE;
+ gains->header.size = sizeof(struct mali_c55_params_awb_gains);
+
+ gains->gain00 = 256;
+ gains->gain00 = 256;
+ gains->gain00 = 256;
+ gains->gain00 = 256;
+
+ data += sizeof(struct mali_c55_params_awb_gains);
+ params->data_size += sizeof(struct mali_c55_params_awb_gains);
+
+ struct mali_c55_params_sensor_off_preshading *blc =
+ (struct mali_c55_params_sensor_off_preshading *)data;
+
+ blc->header.type = MALI_C55_PARAM_BLOCK_SENSOR_OFFS;
+ blc->header.flags |= V4L2_ISP_PARAMS_FL_BLOCK_ENABLE;
+ blc->header.size = sizeof(struct mali_c55_params_sensor_off_preshading);
+
+ blc->chan00 = 51200;
+ blc->chan01 = 51200;
+ blc->chan10 = 51200;
+ blc->chan11 = 51200;
+
+ params->data_size += sizeof(struct
mali_c55_params_sensor_off_preshading);
+
Arm Mali-C55 uAPI data types
============================
_______________________________________________
linuxtv-commits mailing list -- [email protected]
To unsubscribe send an email to [email protected]
