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+.. SPDX-License-Identifier: GPL-2.0
+.. c:namespace:: V4L
+
+.. _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_EXT_PARAMS ('rk1e')
+************************************************************************************************************************
+
+========================
+Configuration parameters
+========================
+
+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 `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
+===========================
+
+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:: include/uapi/linux/rkisp1-config.h