From: Keke Li Date: Sun, 27 Apr 2025 06:27:18 +0000 (+0800) Subject: Documentation: media: Add documentation file c3-isp.rst X-Git-Tag: v6.16-rc1~145^2~18 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8953ee959546ae8faaa20f405647e5aecc42614;p=thirdparty%2Flinux.git Documentation: media: Add documentation file c3-isp.rst Add the file 'c3-isp.rst' that documents the c3-isp driver. Signed-off-by: Keke Li Signed-off-by: Jacopo Mondi Signed-off-by: Hans Verkuil --- diff --git a/Documentation/admin-guide/media/c3-isp.dot b/Documentation/admin-guide/media/c3-isp.dot new file mode 100644 index 0000000000000..42dc931ee84a7 --- /dev/null +++ b/Documentation/admin-guide/media/c3-isp.dot @@ -0,0 +1,26 @@ +digraph board { + rankdir=TB + n00000001 [label="{{ 0 | 1} | c3-isp-core\n/dev/v4l-subdev0 | { 2 | 3 | 4 | 5}}", shape=Mrecord, style=filled, fillcolor=green] + n00000001:port3 -> n00000008:port0 + n00000001:port4 -> n0000000b:port0 + n00000001:port5 -> n0000000e:port0 + n00000001:port2 -> n00000027 + n00000008 [label="{{ 0} | c3-isp-resizer0\n/dev/v4l-subdev1 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n00000008:port1 -> n00000016 [style=bold] + n0000000b [label="{{ 0} | c3-isp-resizer1\n/dev/v4l-subdev2 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n0000000b:port1 -> n0000001a [style=bold] + n0000000e [label="{{ 0} | c3-isp-resizer2\n/dev/v4l-subdev3 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n0000000e:port1 -> n00000023 [style=bold] + n00000011 [label="{{ 0} | c3-mipi-adapter\n/dev/v4l-subdev4 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n00000011:port1 -> n00000001:port0 [style=bold] + n00000016 [label="c3-isp-cap0\n/dev/video0", shape=box, style=filled, fillcolor=yellow] + n0000001a [label="c3-isp-cap1\n/dev/video1", shape=box, style=filled, fillcolor=yellow] + n0000001e [label="{{ 0} | c3-mipi-csi2\n/dev/v4l-subdev5 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n0000001e:port1 -> n00000011:port0 [style=bold] + n00000023 [label="c3-isp-cap2\n/dev/video2", shape=box, style=filled, fillcolor=yellow] + n00000027 [label="c3-isp-stats\n/dev/video3", shape=box, style=filled, fillcolor=yellow] + n0000002b [label="c3-isp-params\n/dev/video4", shape=box, style=filled, fillcolor=yellow] + n0000002b -> n00000001:port1 + n0000003f [label="{{} | imx290 2-001a\n/dev/v4l-subdev6 | { 0}}", shape=Mrecord, style=filled, fillcolor=green] + n0000003f:port0 -> n0000001e:port0 [style=bold] +} diff --git a/Documentation/admin-guide/media/c3-isp.rst b/Documentation/admin-guide/media/c3-isp.rst new file mode 100644 index 0000000000000..ac508b8c68319 --- /dev/null +++ b/Documentation/admin-guide/media/c3-isp.rst @@ -0,0 +1,101 @@ +.. SPDX-License-Identifier: (GPL-2.0-only OR MIT) + +.. include:: + +================================================= +Amlogic C3 Image Signal Processing (C3ISP) driver +================================================= + +Introduction +============ + +This file documents the Amlogic C3ISP driver located under +drivers/media/platform/amlogic/c3/isp. + +The current version of the driver supports the C3ISP found on +Amlogic C308L processor. + +The driver implements V4L2, Media controller and V4L2 subdev interfaces. +Camera sensor using V4L2 subdev interface in the kernel is supported. + +The driver has been tested on AW419-C308L-Socket platform. + +Amlogic C3 ISP +============== + +The Camera hardware found on C308L processors and supported by +the driver consists of: + +- 1 MIPI-CSI-2 module: handles the physical layer of the MIPI CSI-2 receiver and + receives data from the connected camera sensor. +- 1 MIPI-ADAPTER module: organizes MIPI data to meet ISP input requirements and + send MIPI data to ISP. +- 1 ISP (Image Signal Processing) module: contains a pipeline of image processing + hardware blocks. The ISP pipeline contains three resizers at the end each of + them connected to a DMA interface which writes the output data to memory. + +A high-level functional view of the C3 ISP is presented below.:: + + +----------+ +-------+ + | Resizer |--->| WRMIF | + +---------+ +------------+ +--------------+ +-------+ |----------+ +-------+ + | Sensor |--->| MIPI CSI-2 |--->| MIPI ADAPTER |--->| ISP |---|----------+ +-------+ + +---------+ +------------+ +--------------+ +-------+ | Resizer |--->| WRMIF | + +----------+ +-------+ + |----------+ +-------+ + | Resizer |--->| WRMIF | + +----------+ +-------+ + +Driver architecture and design +============================== + +With the goal to model the hardware links between the modules and to expose a +clean, logical and usable interface, the driver registers the following V4L2 +sub-devices: + +- 1 `c3-mipi-csi2` sub-device - the MIPI CSI-2 receiver +- 1 `c3-mipi-adapter` sub-device - the MIPI adapter +- 1 `c3-isp-core` sub-device - the ISP core +- 3 `c3-isp-resizer` sub-devices - the ISP resizers + +The `c3-isp-core` sub-device is linked to 2 video device nodes for statistics +capture and parameters programming: + +- the `c3-isp-stats` capture video device node for statistics capture +- the `c3-isp-params` output video device for parameters programming + +Each `c3-isp-resizer` sub-device is linked to a capture video device node where +frames are captured from: + +- `c3-isp-resizer0` is linked to the `c3-isp-cap0` capture video device +- `c3-isp-resizer1` is linked to the `c3-isp-cap1` capture video device +- `c3-isp-resizer2` is linked to the `c3-isp-cap2` capture video device + +The media controller pipeline graph is as follows (with connected a +IMX290 camera sensor): + +.. _isp_topology_graph: + +.. kernel-figure:: c3-isp.dot + :alt: c3-isp.dot + :align: center + + Media pipeline topology + +Implementation +============== + +Runtime configuration of the ISP hardware is performed on the `c3-isp-params` +video device node using the :ref:`V4L2_META_FMT_C3ISP_PARAMS +` as data format. The buffer structure is defined by +:c:type:`c3_isp_params_cfg`. + +Statistics are captured from the `c3-isp-stats` video device node using the +:ref:`V4L2_META_FMT_C3ISP_STATS ` data format. + +The final picture size and format is configured using the V4L2 video +capture interface on the `c3-isp-cap[0, 2]` video device nodes. + +The Amlogic C3 ISP is supported by `libcamera `_ with a +dedicated pipeline handler and algorithms that perform run-time image correction +and enhancement. diff --git a/Documentation/admin-guide/media/v4l-drivers.rst b/Documentation/admin-guide/media/v4l-drivers.rst index e8761561b2fe7..3bac5165b1341 100644 --- a/Documentation/admin-guide/media/v4l-drivers.rst +++ b/Documentation/admin-guide/media/v4l-drivers.rst @@ -10,6 +10,7 @@ Video4Linux (V4L) driver-specific documentation :maxdepth: 2 bttv + c3-isp cafe_ccic cx88 fimc diff --git a/MAINTAINERS b/MAINTAINERS index 627d6e755b166..137122d3dc4e4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1258,6 +1258,8 @@ AMLOGIC ISP DRIVER M: Keke Li L: linux-media@vger.kernel.org S: Maintained +F: Documentation/admin-guide/media/c3-isp.dot +F: Documentation/admin-guide/media/c3-isp.rst F: Documentation/devicetree/bindings/media/amlogic,c3-isp.yaml F: Documentation/userspace-api/media/v4l/metafmt-c3-isp.rst F: drivers/media/platform/amlogic/c3/isp/