media: pixfmt-meta-rkisp1.rst: add description of rkisp1 metadata formats in pixfmt-meta-rkisp1.rst

The metadata formats V4L2_META_FMT_RK_ISP1_PARAMS,
V4L2_META_FMT_RK_ISP1_STAT_3A are currently described in
two files under
drivers/staging/media/rkisp1/Documentation/media/uapi/v4l

This patch moves the description to one file:
Documentation/userspace-api/media/v4l/pixfmt-meta-rkisp1.rst
The patch also extends the description and adds the rst file to
toctree.
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/v4l/meta-formats.rst

@@ -14,6 +14,7 @@ These formats are used for the :ref:`metadata` interface only.
 
     pixfmt-meta-d4xx
     pixfmt-meta-intel-ipu3
+    pixfmt-meta-rkisp1
     pixfmt-meta-uvc
     pixfmt-meta-vsp1-hgo
     pixfmt-meta-vsp1-hgt

Documentation/userspace-api/media/v4l/pixfmt-meta-rkisp1.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+.. _v4l2-meta-fmt-params-rkisp1:
+.. _v4l2-meta-fmt-stat-rkisp1:
+
+*****************************************************************************
+V4L2_META_FMT_RK_ISP1_PARAMS ('rk1p'), V4L2_META_FMT_RK_ISP1_STAT_3A ('rk1s')
+*****************************************************************************
+
+Configuration parameters
+========================
+
+The configuration 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:
+
+.. code-block:: c
+
+	struct rkisp1_params_cfg *params = (struct rkisp1_params_cfg*) buffer;
+
+.. rkisp1_stat_buffer
+
+3A and histogram statistics
+===========================
+
+The ISP1 device collects different statistics over an input Bayer frame.
+Those statistics are obtained from the :ref:`rkisp1_stats <rkisp1_stats>`
+metadata capture video node,
+using the :c:type:`v4l2_meta_format` interface. The buffer contains a single
+instance of the C structure :c:type:`rkisp1_stat_buffer` defined in
+``rkisp1-config.h``. So the structure can be obtained from the buffer by:
+
+.. code-block:: c
+
+	struct rkisp1_stat_buffer *stats = (struct rkisp1_stat_buffer*) buffer;
+
+The statistics collected are Exposure, AWB (Auto-white balance), Histogram and
+AF (Auto-focus). See :c:type:`rkisp1_stat_buffer` for details of the statistics.
+
+The 3A statistics and configuration parameters described here are usually
+consumed and produced by dedicated user space libraries that comprise the
+important tuning tools using software control loop.
+
+rkisp1 uAPI data types
+======================
+
+.. kernel-doc:: drivers/staging/media/rkisp1/uapi/rkisp1-config.h

drivers/staging/media/rkisp1/Documentation/media/uapi/v4l/pixfmt-meta-rkisp1-params.rst

-.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
-
-.. _v4l2-meta-fmt-rkisp1-params:
-
-============================
-V4L2_META_FMT_RK_ISP1_PARAMS
-============================
-
-Rockchip ISP1 Parameters Data
-
-Description
-===========
-
-This format describes input parameters for the Rockchip ISP1.
-
-It uses c-struct :c:type:`rkisp1_params_cfg`, which is defined in
-the ``linux/rkisp1-config.h`` header file.
-
-The parameters consist of multiple modules.
-The module won't be updated if the corresponding bit was not set in module_*_update.
-
-.. kernel-doc:: include/uapi/linux/rkisp1-config.h
-   :functions: rkisp1_params_cfg

drivers/staging/media/rkisp1/Documentation/media/uapi/v4l/pixfmt-meta-rkisp1-stat.rst

-.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
-
-.. _v4l2-meta-fmt-rkisp1-stat:
-
-=============================
-V4L2_META_FMT_RK_ISP1_STAT_3A
-=============================
-
-
-Rockchip ISP1 Statistics Data
-
-Description
-===========
-
-This format describes image color statistics information generated by the Rockchip
-ISP1.
-
-It uses c-struct :c:type:`rkisp1_stat_buffer`, which is defined in
-the ``linux/rkisp1-config.h`` header file.
-
-.. kernel-doc:: include/uapi/linux/rkisp1-config.h
-   :functions: rkisp1_stat_buffer