@@ -64,5 +64,6 @@ For more details see the file COPYING in the source distribution of Linux.
si476x
soc-camera
uvcvideo
+ vimc
vivid
zr364xx
new file mode 100644
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+
+digraph board {
+ rankdir=TB
+ n00000001 [label="{{} | Sensor A\n/dev/v4l-subdev0 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000001:port0 -> n00000005:port0 [style=bold]
+ n00000001:port0 -> n0000000b [style=bold]
+ n00000003 [label="{{} | Sensor B\n/dev/v4l-subdev1 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000003:port0 -> n00000008:port0 [style=bold]
+ n00000003:port0 -> n0000000f [style=bold]
+ n00000005 [label="{{<port0> 0} | Debayer A\n/dev/v4l-subdev2 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000005:port1 -> n00000017:port0
+ n00000008 [label="{{<port0> 0} | Debayer B\n/dev/v4l-subdev3 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000008:port1 -> n00000017:port0 [style=dashed]
+ n0000000b [label="Raw Capture 0\n/dev/video0", shape=box, style=filled, fillcolor=yellow]
+ n0000000f [label="Raw Capture 1\n/dev/video1", shape=box, style=filled, fillcolor=yellow]
+ n00000013 [label="RGB/YUV Input\n/dev/video2", shape=box, style=filled, fillcolor=yellow]
+ n00000013 -> n00000017:port0 [style=dashed]
+ n00000017 [label="{{<port0> 0} | Scaler\n/dev/v4l-subdev4 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green]
+ n00000017:port1 -> n0000001a [style=bold]
+ n0000001a [label="RGB/YUV Capture\n/dev/video3", shape=box, style=filled, fillcolor=yellow]
+}
new file mode 100644
@@ -0,0 +1,98 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The Virtual Media Controller Driver (vimc)
+==========================================
+
+The vimc driver emulates complex video hardware using the V4L2 API and the Media
+API. It has a capture device and three subdevices: sensor, debayer and scaler.
+
+Topology
+--------
+
+The topology is hardcoded, although you could modify it in vimc-core and
+recompile the driver to achieve your own topology. This is the default topology:
+
+.. _vimc_topology_graph:
+
+.. kernel-figure:: vimc.dot
+ :alt: vimc.dot
+ :align: center
+
+ Media pipeline graph on vimc
+
+Configuring the topology
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Each subdevice will come with its default configuration (pixelformat, height,
+width, ...). One needs to configure the topology in order to match the
+configuration on each linked subdevice to stream frames through the pipeline.
+If the configuration doesn't match, the stream will fail. The ``v4l2-utils``
+is a bundle of user-space applications, that comes with ``media-ctl`` and
+``v4l2-ctl`` that can be used to configure the vimc configuration. This sequence
+of commands fits for the default topology:
+
+.. code-block:: bash
+
+ media-ctl -d platform:vimc -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]'
+ media-ctl -d platform:vimc -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]'
+ media-ctl -d platform:vimc -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]'
+ media-ctl -d platform:vimc -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]'
+ v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
+ v4l2-ctl -z platform:vimc -d "Raw Capture 0" -v pixelformat=BA81
+ v4l2-ctl -z platform:vimc -d "Raw Capture 1" -v pixelformat=BA81
+
+Subdevices
+----------
+
+Subdevices define the behavior of an entity in the topology. Depending on the
+subdevice, the entity can have multiple pads of type source or sink.
+
+vimc-sensor:
+ Generates images in several formats using video test pattern generator.
+ Exposes:
+
+ * 1 Pad source
+
+vimc-debayer:
+ Transforms images in bayer format into a non-bayer format.
+ Exposes:
+
+ * 1 Pad sink
+ * 1 Pad source
+
+vimc-scaler:
+ Scale up the image by a factor of 3. E.g.: a 640x480 image becomes a
+ 1920x1440 image. (this value can be configured, see at
+ `Module options`_).
+ Exposes:
+
+ * 1 Pad sink
+ * 1 Pad source
+
+vimc-capture:
+ Exposes node /dev/videoX to allow userspace to capture the stream.
+ Exposes:
+
+ * 1 Pad sink
+ * 1 Pad source
+
+Module options
+---------------
+
+Vimc has a few module parameters to configure the driver. You should pass
+those arguments to each subdevice, not to the vimc module. For example::
+
+ vimc_subdevice.param=value
+
+* ``vimc_scaler.sca_mult=<unsigned int>``
+
+ Image size multiplier factor to be used to multiply both width and
+ height, so the image size will be ``sca_mult^2`` bigger than the
+ original one. Currently, only supports scaling up (the default value
+ is 3).
+
+* ``vimc_debayer.deb_mean_win_size=<unsigned int>``
+
+ Window size to calculate the mean. Note: the window size needs to be an
+ odd number, as the main pixel stays in the center of the window,
+ otherwise the next odd number is considered (the default value is 3).
Create vimc documentation file to explain it basics features, it's topology, how to configure it and to document vimc's subdevices. Signed-off-by: André Almeida <andrealmeid@collabora.com> Suggested-by: Helen Koike <helen.koike@collabora.com> --- Commit extracted from [PATCH 0/4] media: vimc: Minor code cleanup and documentation Changes in v2: - Fix typos - Make clear what does means scale factor Documentation/media/v4l-drivers/index.rst | 1 + Documentation/media/v4l-drivers/vimc.dot | 22 +++++ Documentation/media/v4l-drivers/vimc.rst | 98 +++++++++++++++++++++++ 3 files changed, 121 insertions(+) create mode 100644 Documentation/media/v4l-drivers/vimc.dot create mode 100644 Documentation/media/v4l-drivers/vimc.rst