[PATCH v8 2/8] media: admin-guide: Add starfive_camss.rst for Starfive Camera Subsystem

Jack Zhu
2023-08-24T08:03:42Z

Add starfive_camss.rst file that documents the Starfive Camera
Subsystem driver which is used for handing image sensor data.

Signed-off-by: Jack Zhu <jack.zhu@starfivetech.com>
---
.../admin-guide/media/starfive_camss.rst | 72 +++++++++++++++++++
.../media/starfive_camss_graph.dot | 12 ++++
.../admin-guide/media/v4l-drivers.rst | 1 +
MAINTAINERS | 1 +
4 files changed, 86 insertions(+)
create mode 100644 Documentation/admin-guide/media/starfive_camss.rst
create mode 100644 Documentation/admin-guide/media/starfive_camss_graph.dot

diff --git a/Documentation/admin-guide/media/starfive_camss.rst b/Documentation/admin-guide/media/starfive_camss.rst
new file mode 100644
index 000000000000..ca42e9447c47
--- /dev/null
+++ b/Documentation/admin-guide/media/starfive_camss.rst
@@ -0,0 +1,72 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. include:: <isonum.txt>
+
+================================
+Starfive Camera Subsystem driver
+================================
+
+Introduction
+------------
+
+This file documents the driver for the Starfive Camera Subsystem found on
+Starfive JH7110 SoC. The driver is located under drivers/staging/media/starfive/
+camss.
+
+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 successfully used on the Gstreamer 1.18.5 with v4l2src
+plugin.
+
+
+Starfive Camera Subsystem hardware
+----------------------------------
+
+The Starfive Camera Subsystem hardware consists of::
+
+ |\ +---------------+ +-----------+
+ +----------+ | \ | | | |
+ | | | | | | | |
+ | MIPI |----->| |----->| ISP |----->| |
+ | | | | | | | |
+ +----------+ | | | | | Memory |
+ |MUX| +---------------+ | Interface |
+ +----------+ | | | |
+ | | | |---------------------------->| |
+ | Parallel |----->| | | |
+ | | | | | |
+ +----------+ | / | |
+ |/ +-----------+
+
+- MIPI: The MIPI interface, receiving data from a MIPI CSI-2 camera sensor.
+
+- Parallel: The parallel interface, receiving data from a parallel sensor.
+
+- ISP: The ISP, processing raw Bayer data from an image sensor and producing
+ YUV frames.
+
+
+Topology
+--------
+
+The media controller pipeline graph is as follows:
+
+.. _starfive_camss_graph:
+
+.. kernel-figure:: starfive_camss_graph.dot
+ :alt: starfive_camss_graph.dot
+ :align: center
+
+The driver has 2 video devices:
+
+- capture_raw: The capture device, capturing image data directly from a sensor.
+- capture_yuv: The capture device, capturing YUV frame data processed by the
+ ISP module
+
+The driver has 3 subdevices:
+
+- stf_isp: is responsible for all the isp operations, outputs YUV frames.
+- cdns_csi2rx: a CSI-2 bridge supporting up to 4 CSI lanes in input, and 4
+ different pixel streams in output.
+- imx219: an image sensor, image data is sent through MIPI CSI-2.
diff --git a/Documentation/admin-guide/media/starfive_camss_graph.dot b/Documentation/admin-guide/media/starfive_camss_graph.dot
new file mode 100644
index 000000000000..8eff1f161ac7
--- /dev/null
+++ b/Documentation/admin-guide/media/starfive_camss_graph.dot
@@ -0,0 +1,12 @@
+digraph board {
+ rankdir=TB
+ n00000001 [label="{{<port0> 0} | stf_isp\n/dev/v4l-subdev0 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000001:port1 -> n00000008 [style=dashed]
+ n00000004 [label="capture_raw\n/dev/video0", shape=box, style=filled, fillcolor=yellow]
+ n00000008 [label="capture_yuv\n/dev/video1", shape=box, style=filled, fillcolor=yellow]
+ n0000000e [label="{{<port0> 0} | cdns_csi2rx.19800000.csi-bridge\n | {<port1> 1 | <port2> 2 | <port3> 3 | <port4> 4}}", shape=Mrecord, style=filled, fillcolor=green]
+ n0000000e:port1 -> n00000001:port0 [style=dashed]
+ n0000000e:port1 -> n00000004 [style=dashed]
+ n00000018 [label="{{} | imx219 6-0010\n/dev/v4l-subdev1 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000018:port0 -> n0000000e:port0 [style=bold]
+}
diff --git a/Documentation/admin-guide/media/v4l-drivers.rst b/Documentation/admin-guide/media/v4l-drivers.rst
index 1c41f87c3917..2274fd29c1d7 100644
--- a/Documentation/admin-guide/media/v4l-drivers.rst
+++ b/Documentation/admin-guide/media/v4l-drivers.rst
@@ -27,6 +27,7 @@ Video4Linux (V4L) driver-specific documentation
si470x
si4713
si476x
+ starfive_camss
vimc
visl
vivid
diff --git a/MAINTAINERS b/MAINTAINERS
index a2263f9bbead..4c63c0a85301 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20256,6 +20256,7 @@ M: Jack Zhu <jack.zhu@starfivetech.com>
M: Changhuang Liang <changhuang.liang@starfivetech.com>
L: linux-media@vger.kernel.org
S: Maintained
+F: Documentation/admin-guide/media/starfive_camss.rst
F: Documentation/devicetree/bindings/media/starfive,jh7110-camss.yaml

STARFIVE CRYPTO DRIVER
--
2.34.1