diff options
Diffstat (limited to 'Documentation/media/v4l-drivers')
| -rw-r--r-- | Documentation/media/v4l-drivers/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/media/v4l-drivers/vimc.dot | 22 | ||||
| -rw-r--r-- | Documentation/media/v4l-drivers/vimc.rst | 98 | ||||
| -rw-r--r-- | Documentation/media/v4l-drivers/vivid.rst | 5 |
4 files changed, 126 insertions, 0 deletions
diff --git a/Documentation/media/v4l-drivers/index.rst b/Documentation/media/v4l-drivers/index.rst index 33a055907258..c4c78a28654c 100644 --- a/Documentation/media/v4l-drivers/index.rst +++ b/Documentation/media/v4l-drivers/index.rst @@ -64,5 +64,6 @@ For more details see the file COPYING in the source distribution of Linux. si476x soc-camera uvcvideo + vimc vivid zr364xx diff --git a/Documentation/media/v4l-drivers/vimc.dot b/Documentation/media/v4l-drivers/vimc.dot new file mode 100644 index 000000000000..57863a13fa39 --- /dev/null +++ b/Documentation/media/v4l-drivers/vimc.dot @@ -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] +} diff --git a/Documentation/media/v4l-drivers/vimc.rst b/Documentation/media/v4l-drivers/vimc.rst new file mode 100644 index 000000000000..4628b12d417f --- /dev/null +++ b/Documentation/media/v4l-drivers/vimc.rst @@ -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 ``v4l-utils`` +package 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). diff --git a/Documentation/media/v4l-drivers/vivid.rst b/Documentation/media/v4l-drivers/vivid.rst index edb6f33e029c..7082fec4075d 100644 --- a/Documentation/media/v4l-drivers/vivid.rst +++ b/Documentation/media/v4l-drivers/vivid.rst @@ -941,6 +941,11 @@ Digital Video Controls affects the reported colorspace since DVI_D outputs will always use sRGB. +- Display Present: + + sets the presence of a "display" on the HDMI output. This affects + the tx_edid_present, tx_hotplug and tx_rxsense controls. + FM Radio Receiver Controls ~~~~~~~~~~~~~~~~~~~~~~~~~~ |