@@ -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
==============================
@@ -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
===========================
@@ -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;
@@ -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 */