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media: uapi: videodev2: Add V4L2_META_FMT_RK_ISP1_EXT_PARAMS

The rkisp1 driver stores ISP configuration parameters in the fixed
rkisp1_params_cfg structure. As the members of the structure are part of
the userspace API, the structure layout is immutable and cannot be
extended further. Introducing new parameters or modifying the existing
ones would change the buffer layout and cause breakages in existing
applications.

The allow for future extensions to the ISP parameters, introduce a new
extensible parameters format, with a new format 4CC. Document usage of
the new format in the rkisp1 admin guide.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This commit is contained in:
Jacopo Mondi 2024-08-08 22:40:55 +02:00 committed by Laurent Pinchart
parent e9d05e9d5d
commit 1fc379f624
4 changed files with 59 additions and 11 deletions

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@ -114,11 +114,18 @@ to be applied to the hardware during a video stream, allowing userspace
to dynamically modify values such as black level, cross talk corrections
and others.
The buffer format is defined by struct :c:type:`rkisp1_params_cfg`, and
userspace should set
The ISP driver supports two different parameters configuration methods, the
`fixed parameters format` or the `extensible parameters format`.
When using the `fixed parameters` method the buffer format is defined by struct
:c:type:`rkisp1_params_cfg`, and userspace should set
:ref:`V4L2_META_FMT_RK_ISP1_PARAMS <v4l2-meta-fmt-rk-isp1-params>` as the
dataformat.
When using the `extensible parameters` method the buffer format is defined by
struct :c:type:`rkisp1_ext_params_cfg`, and userspace should set
:ref:`V4L2_META_FMT_RK_ISP1_EXT_PARAMS <v4l2-meta-fmt-rk-isp1-ext-params>` as
the dataformat.
Capturing Video Frames Example
==============================

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@ -1,28 +1,67 @@
.. SPDX-License-Identifier: GPL-2.0
.. _v4l2-meta-fmt-rk-isp1-params:
.. _v4l2-meta-fmt-rk-isp1-stat-3a:
*****************************************************************************
V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s')
*****************************************************************************
************************************************************************************************************************
V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s'), V4L2_META_FMT_RK_ISP1_EXT_PARAMS ('rk1e')
************************************************************************************************************************
========================
Configuration parameters
========================
The configuration parameters are passed to the
The configuration of the RkISP1 ISP is performed by userspace by providing
parameters for the ISP to the driver using the :c:type:`v4l2_meta_format`
interface.
There are two methods that allow to configure the ISP, the `fixed parameters`
configuration format and the `extensible parameters` configuration
format.
.. _v4l2-meta-fmt-rk-isp1-params:
Fixed parameters configuration format
=====================================
When using the fixed configuration format, parameters are passed to the
:ref:`rkisp1_params <rkisp1_params>` metadata output video node, using
the :c:type:`v4l2_meta_format` interface. The buffer contains
a single instance of the C structure :c:type:`rkisp1_params_cfg` defined in
``rkisp1-config.h``. So the structure can be obtained from the buffer by:
the `V4L2_META_FMT_RK_ISP1_PARAMS` meta format.
The buffer contains a single instance of the C structure
:c:type:`rkisp1_params_cfg` defined in ``rkisp1-config.h``. So the structure can
be obtained from the buffer by:
.. code-block:: c
struct rkisp1_params_cfg *params = (struct rkisp1_params_cfg*) buffer;
This method supports a subset of the ISP features only, new applications should
use the extensible parameters method.
.. _v4l2-meta-fmt-rk-isp1-ext-params:
Extensible parameters configuration format
==========================================
When using the extensible configuration format, parameters are passed to the
:ref:`rkisp1_params <rkisp1_params>` metadata output video node, using
the `V4L2_META_FMT_RK_ISP1_EXT_PARAMS` meta format.
The buffer contains a single instance of the C structure
:c:type:`rkisp1_ext_params_cfg` defined in ``rkisp1-config.h``. The
:c:type:`rkisp1_ext_params_cfg` structure is designed to allow userspace to
populate the data buffer with only the configuration data for the ISP blocks it
intends to configure. The extensible parameters format design allows developers
to define new block types to support new configuration parameters, and defines a
versioning scheme so that it can be extended and versioned without breaking
compatibility with existing applications.
For these reasons, this configuration method is preferred over the `fixed
parameters` format alternative.
.. rkisp1_stat_buffer
===========================
3A and histogram statistics
===========================

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@ -1458,6 +1458,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
case V4L2_META_FMT_VIVID: descr = "Vivid Metadata"; break;
case V4L2_META_FMT_RK_ISP1_PARAMS: descr = "Rockchip ISP1 3A Parameters"; break;
case V4L2_META_FMT_RK_ISP1_STAT_3A: descr = "Rockchip ISP1 3A Statistics"; break;
case V4L2_META_FMT_RK_ISP1_EXT_PARAMS: descr = "Rockchip ISP1 Ext 3A Params"; break;
case V4L2_PIX_FMT_NV12_8L128: descr = "NV12 (8x128 Linear)"; break;
case V4L2_PIX_FMT_NV12M_8L128: descr = "NV12M (8x128 Linear)"; break;
case V4L2_PIX_FMT_NV12_10BE_8L128: descr = "10-bit NV12 (8x128 Linear, BE)"; break;

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@ -854,6 +854,7 @@ struct v4l2_pix_format {
/* Vendor specific - used for RK_ISP1 camera sub-system */
#define V4L2_META_FMT_RK_ISP1_PARAMS v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
#define V4L2_META_FMT_RK_ISP1_STAT_3A v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
#define V4L2_META_FMT_RK_ISP1_EXT_PARAMS v4l2_fourcc('R', 'K', '1', 'E') /* Rockchip ISP1 3a Extensible Parameters */
/* Vendor specific - used for RaspberryPi PiSP */
#define V4L2_META_FMT_RPI_BE_CFG v4l2_fourcc('R', 'P', 'B', 'C') /* PiSP BE configuration */