[v4,02/13] media: Documentation: Add description for StarFive ISP metadata formats

Commit Message

Changhuang Liang April 2, 2024, 10 a.m. UTC

Add description for V4L2_META_FMT_STF_ISP_PARAMS and
V4L2_META_FMT_STF_ISP_STAT_3A meta data formats.

Signed-off-by: Changhuang Liang <[e-mail]>
---
 .../media/v4l/metafmt-starfive-isp.rst        | 75 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 76 insertions(+)
 create mode 100644 Documentation/userspace-api/media/v4l/metafmt-starfive-isp.rst

Patch

diff --git a/Documentation/userspace-api/media/v4l/metafmt-starfive-isp.rst b/Documentation/userspace-api/media/v4l/metafmt-starfive-isp.rst
new file mode 100644
index 000000000000..ebb4291833d6
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/metafmt-starfive-isp.rst
@@ -0,0 +1,75 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _v4l2-meta-fmt-stf-isp-params:
+
+.. _v4l2-meta-fmt-stf-isp-stat-3a:
+
+*****************************************************************************
+V4L2_META_FMT_STF_ISP_PARAMS ('stfp'), V4L2_META_FMT_STF_ISP_STAT_3A ('stfs')
+*****************************************************************************
+
+.. jh7110_isp_params_buffer
+
+Configuration parameters
+========================
+
+The configuration parameters are passed to the "output_params" metadata output
+video node, using the :c:type:`v4l2_meta_format` interface. They are formatted
+as described by the :c:type:`jh7110_isp_params_buffer` structure.
+
+.. code-block:: c
+
+	struct jh7110_isp_params_buffer {
+		__u32 enable_setting;
+		struct jh7110_isp_wb_setting wb_setting;
+		struct jh7110_isp_car_setting car_setting;
+		struct jh7110_isp_ccm_setting ccm_setting;
+		struct jh7110_isp_cfa_setting cfa_setting;
+		struct jh7110_isp_ctc_setting ctc_setting;
+		struct jh7110_isp_dbc_setting dbc_setting;
+		struct jh7110_isp_dnyuv_setting dnyuv_setting;
+		struct jh7110_isp_gmargb_setting gmargb_setting;
+		struct jh7110_isp_lccf_setting lccf_setting;
+		struct jh7110_isp_obc_setting obc_setting;
+		struct jh7110_isp_oecf_setting oecf_setting;
+		struct jh7110_isp_r2y_setting r2y_setting;
+		struct jh7110_isp_sat_setting sat_setting;
+		struct jh7110_isp_sharp_setting sharp_setting;
+		struct jh7110_isp_ycrv_setting ycrv_setting;
+		struct jh7110_isp_sc_setting sc_setting;
+	};
+
+.. jh7110_isp_sc_buffer
+
+3A and histogram statistics
+===========================
+
+The ISP device collects different statistics over an input Bayer frame.
+Those statistics are obtained from the "capture_scd" metadata capture video
+node, using the :c:type:`v4l2_meta_format` interface. They are formatted as
+described by the :c:type:`jh7110_isp_sc_buffer` structure.
+
+.. code-block:: c
+
+	struct jh7110_isp_sc_buffer {
+		__u32 y_histogram[64];
+		__u32 reserv0[33];
+		__u32 bright_sc[4096];
+		__u32 reserv1[96];
+		__u32 ae_hist_y[128];
+		__u32 reserv2[511];
+		__u16 flag;
+	};
+
+The statistics collected are Auto Exposure, AWB (Auto-white balance), Histogram
+and AF (Auto-focus). See :c:type:`jh7110_isp_sc_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.
+
+JH7110 ISP uAPI data types
+======================
+
+.. kernel-doc:: include/uapi/linux/jh7110-isp.h
diff --git a/MAINTAINERS b/MAINTAINERS
index e5ed3c876a55..4ec5977a47f4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20954,6 +20954,7 @@  L:	[e-mail]
 S:	Maintained
 F:	Documentation/admin-guide/media/starfive_camss.rst
 F:	Documentation/devicetree/bindings/media/starfive,jh7110-camss.yaml
+F:	Documentation/userspace-api/media/v4l/metafmt-starfive-isp.rst
 F:	drivers/staging/media/starfive/camss
 F:	include/uapi/linux/jh7110-isp.h