diff options
Diffstat (limited to 'Documentation/userspace-api/media')
14 files changed, 344 insertions, 63 deletions
diff --git a/Documentation/userspace-api/media/drivers/aspeed-video.rst b/Documentation/userspace-api/media/drivers/aspeed-video.rst index 1b0cb1e3eba8..567387aca6b0 100644 --- a/Documentation/userspace-api/media/drivers/aspeed-video.rst +++ b/Documentation/userspace-api/media/drivers/aspeed-video.rst @@ -23,7 +23,7 @@ proprietary mode. More details on the ASPEED video hardware operations can be found in *chapter 6.2.16 KVM Video Driver* of SDK_User_Guide which available on -AspeedTech-BMC/openbmc/releases. +`github <https://github.com/AspeedTech-BMC/openbmc/releases/>`__. The ASPEED video driver implements the following driver-specific control: diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst index 915dbf0f4db5..6708d649afd7 100644 --- a/Documentation/userspace-api/media/drivers/index.rst +++ b/Documentation/userspace-api/media/drivers/index.rst @@ -37,7 +37,6 @@ For more details see the file COPYING in the source distribution of Linux. dw100 imx-uapi max2175 - meye-uapi omap3isp-uapi st-vgxy61 uvcvideo diff --git a/Documentation/userspace-api/media/drivers/meye-uapi.rst b/Documentation/userspace-api/media/drivers/meye-uapi.rst deleted file mode 100644 index 66b1c142f920..000000000000 --- a/Documentation/userspace-api/media/drivers/meye-uapi.rst +++ /dev/null @@ -1,53 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -.. include:: <isonum.txt> - -Vaio Picturebook Motion Eye Camera Driver -========================================= - -Copyright |copy| 2001-2004 Stelian Pop <stelian@popies.net> - -Copyright |copy| 2001-2002 Alcôve <www.alcove.com> - -Copyright |copy| 2000 Andrew Tridgell <tridge@samba.org> - -Private API ------------ - -The driver supports frame grabbing with the video4linux API, -so all video4linux tools (like xawtv) should work with this driver. - -Besides the video4linux interface, the driver has a private interface -for accessing the Motion Eye extended parameters (camera sharpness, -agc, video framerate), the snapshot and the MJPEG capture facilities. - -This interface consists of several ioctls (prototypes and structures -can be found in include/linux/meye.h): - -MEYEIOC_G_PARAMS and MEYEIOC_S_PARAMS - Get and set the extended parameters of the motion eye camera. - The user should always query the current parameters with - MEYEIOC_G_PARAMS, change what he likes and then issue the - MEYEIOC_S_PARAMS call (checking for -EINVAL). The extended - parameters are described by the meye_params structure. - - -MEYEIOC_QBUF_CAPT - Queue a buffer for capture (the buffers must have been - obtained with a VIDIOCGMBUF call and mmap'ed by the - application). The argument to MEYEIOC_QBUF_CAPT is the - buffer number to queue (or -1 to end capture). The first - call to MEYEIOC_QBUF_CAPT starts the streaming capture. - -MEYEIOC_SYNC - Takes as an argument the buffer number you want to sync. - This ioctl blocks until the buffer is filled and ready - for the application to use. It returns the buffer size. - -MEYEIOC_STILLCAPT and MEYEIOC_STILLJCAPT - Takes a snapshot in an uncompressed or compressed jpeg format. - This ioctl blocks until the snapshot is done and returns (for - jpeg snapshot) the size of the image. The image data is - available from the first mmap'ed buffer. - -Look at the 'motioneye' application code for an actual example. diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst index fd1de0a73a9f..a4f1df7093e8 100644 --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst @@ -29,6 +29,8 @@ will feature a character device node on which ioctls can be called to - negotiate image formats on individual pads +- inspect and modify internal data routing between pads of the same entity + Sub-device character device nodes, conventionally named ``/dev/v4l-subdev*``, use major number 81. @@ -404,6 +406,8 @@ pixel array is not rectangular but cross-shaped or round. The maximum size may also be smaller than the BOUNDS rectangle. +.. _format-propagation: + Order of configuration and format propagation --------------------------------------------- @@ -501,3 +505,165 @@ source pads. :maxdepth: 1 subdev-formats + +Streams, multiplexed media pads and internal routing +---------------------------------------------------- + +Simple V4L2 sub-devices do not support multiple, unrelated video streams, +and only a single stream can pass through a media link and a media pad. +Thus each pad contains a format and selection configuration for that +single stream. A subdev can do stream processing and split a stream into +two or compose two streams into one, but the inputs and outputs for the +subdev are still a single stream per pad. + +Some hardware, e.g. MIPI CSI-2, support multiplexed streams, that is, multiple +data streams are transmitted on the same bus, which is represented by a media +link connecting a transmitter source pad with a sink pad on the receiver. For +example, a camera sensor can produce two distinct streams, a pixel stream and a +metadata stream, which are transmitted on the multiplexed data bus, represented +by a media link which connects the single sensor's source pad with the receiver +sink pad. The stream-aware receiver will de-multiplex the streams received on +the its sink pad and allows to route them individually to one of its source +pads. + +Subdevice drivers that support multiplexed streams are compatible with +non-multiplexed subdev drivers, but, of course, require a routing configuration +where the link between those two types of drivers contains only a single +stream. + +Understanding streams +^^^^^^^^^^^^^^^^^^^^^ + +A stream is a stream of content (e.g. pixel data or metadata) flowing through +the media pipeline from a source (e.g. a sensor) towards the final sink (e.g. a +receiver and demultiplexer in a SoC). Each media link carries all the enabled +streams from one end of the link to the other, and sub-devices have routing +tables which describe how the incoming streams from sink pads are routed to the +source pads. + +A stream ID is a media pad-local identifier for a stream. Streams IDs of +the same stream must be equal on both ends of a link. In other words, +a particular stream ID must exist on both sides of a media +link, but another stream ID can be used for the same stream at the other side +of the sub-device. + +A stream at a specific point in the media pipeline is identified by the +sub-device and a (pad, stream) pair. For sub-devices that do not support +multiplexed streams the 'stream' field is always 0. + +Interaction between routes, streams, formats and selections +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The addition of streams to the V4L2 sub-device interface moves the sub-device +formats and selections from pads to (pad, stream) pairs. Besides the +usual pad, also the stream ID needs to be provided for setting formats and +selections. The order of configuring formats and selections along a stream is +the same as without streams (see :ref:`format-propagation`). + +Instead of the sub-device wide merging of streams from all sink pads +towards all source pads, data flows for each route are separate from each +other. Any number of routes from streams on sink pads towards streams on +source pads is allowed, to the extent supported by drivers. For every +stream on a source pad, however, only a single route is allowed. + +Any configurations of a stream within a pad, such as format or selections, +are independent of similar configurations on other streams. This is +subject to change in the future. + +Configuring streams +^^^^^^^^^^^^^^^^^^^ + +The configuration of the streams is done individually for each sub-device and +the validity of the streams between sub-devices is validated when the pipeline +is started. + +There are three steps in configuring the streams: + +1) Set up links. Connect the pads between sub-devices using the :ref:`Media +Controller API <media_controller>` + +2) Streams. Streams are declared and their routing is configured by +setting the routing table for the sub-device using +:ref:`VIDIOC_SUBDEV_S_ROUTING <VIDIOC_SUBDEV_G_ROUTING>` ioctl. Note that +setting the routing table will reset formats and selections in the +sub-device to default values. + +3) Configure formats and selections. Formats and selections of each stream +are configured separately as documented for plain sub-devices in +:ref:`format-propagation`. The stream ID is set to the same stream ID +associated with either sink or source pads of routes configured using the +:ref:`VIDIOC_SUBDEV_S_ROUTING <VIDIOC_SUBDEV_G_ROUTING>` ioctl. + +Multiplexed streams setup example +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +A simple example of a multiplexed stream setup might be as follows: + +- Two identical sensors (Sensor A and Sensor B). Each sensor has a single source + pad (pad 0) which carries a pixel data stream. + +- Multiplexer bridge (Bridge). The bridge has two sink pads, connected to the + sensors (pads 0, 1), and one source pad (pad 2), which outputs two streams. + +- Receiver in the SoC (Receiver). The receiver has a single sink pad (pad 0), + connected to the bridge, and two source pads (pads 1-2), going to the DMA + engine. The receiver demultiplexes the incoming streams to the source pads. + +- DMA Engines in the SoC (DMA Engine), one for each stream. Each DMA engine is + connected to a single source pad in the receiver. + +The sensors, the bridge and the receiver are modeled as V4L2 sub-devices, +exposed to userspace via /dev/v4l-subdevX device nodes. The DMA engines are +modeled as V4L2 devices, exposed to userspace via /dev/videoX nodes. + +To configure this pipeline, the userspace must take the following steps: + +1) Set up media links between entities: connect the sensors to the bridge, +bridge to the receiver, and the receiver to the DMA engines. This step does +not differ from normal non-multiplexed media controller setup. + +2) Configure routing + +.. flat-table:: Bridge routing table + :header-rows: 1 + + * - Sink Pad/Stream + - Source Pad/Stream + - Routing Flags + - Comments + * - 0/0 + - 2/0 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Pixel data stream from Sensor A + * - 1/0 + - 2/1 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Pixel data stream from Sensor B + +.. flat-table:: Receiver routing table + :header-rows: 1 + + * - Sink Pad/Stream + - Source Pad/Stream + - Routing Flags + - Comments + * - 0/0 + - 1/0 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Pixel data stream from Sensor A + * - 0/1 + - 2/0 + - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - Pixel data stream from Sensor B + +3) Configure formats and selections + +After configuring routing, the next step is configuring the formats and +selections for the streams. This is similar to performing this step without +streams, with just one exception: the ``stream`` field needs to be assigned +to the value of the stream ID. + +A common way to accomplish this is to start from the sensors and propagate the +configurations along the stream towards the receiver, +using :ref:`VIDIOC_SUBDEV_S_FMT <VIDIOC_SUBDEV_G_FMT>` ioctls to configure each +stream endpoint in each sub-device. diff --git a/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst b/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst index 73cd99828010..58f6ae25b2e7 100644 --- a/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst +++ b/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst @@ -271,7 +271,7 @@ please make a proposal on the linux-media mailing list. The implementation is based on AST2600 A3 datasheet, revision 0.9, which is not publicly available. Or you can reference Video stream data format – ASPEED mode compression of SDK_User_Guide which available on - AspeedTech-BMC/openbmc/releases. + `github <https://github.com/AspeedTech-BMC/openbmc/releases/>`__. Decoder's implementation can be found here, `aspeed_codec <https://github.com/AspeedTech-BMC/aspeed_codec/>`__ diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst index 53e604bd7d60..228c1521f190 100644 --- a/Documentation/userspace-api/media/v4l/user-func.rst +++ b/Documentation/userspace-api/media/v4l/user-func.rst @@ -70,6 +70,7 @@ Function Reference vidioc-subdev-g-crop vidioc-subdev-g-fmt vidioc-subdev-g-frame-interval + vidioc-subdev-g-routing vidioc-subdev-g-selection vidioc-subdev-querycap vidioc-subscribe-event diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-interval.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-interval.rst index 3703943b412f..8def4c05d3da 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-interval.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-interval.rst @@ -92,7 +92,10 @@ multiple pads of the same sub-device is not defined. - Frame intervals to be enumerated, from enum :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. * - __u32 - - ``reserved``\ [8] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [7] - Reserved for future extensions. Applications and drivers must set the array to zero. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst index c25a9896df0e..3ef361c0dca7 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-frame-size.rst @@ -97,7 +97,10 @@ information about try formats. - Frame sizes to be enumerated, from enum :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. * - __u32 - - ``reserved``\ [8] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [7] - Reserved for future extensions. Applications and drivers must set the array to zero. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst index 417f1a19bcc4..248f6f9ee7c5 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-enum-mbus-code.rst @@ -73,7 +73,10 @@ information about the try formats. - ``flags`` - See :ref:`v4l2-subdev-mbus-code-flags` * - __u32 - - ``reserved``\ [7] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [6] - Reserved for future extensions. Applications and drivers must set the array to zero. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst index bd15c0a5a66b..1d267f7e7991 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst @@ -96,7 +96,10 @@ modified format should be as close as possible to the original request. - ``rect`` - Crop rectangle boundaries, in pixels. * - __u32 - - ``reserved``\ [8] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [7] - Reserved for future extensions. Applications and drivers must set the array to zero. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst index 7acdbb939d89..ed253a1e44b7 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst @@ -102,7 +102,10 @@ should be as close as possible to the original request. - Definition of an image format, see :c:type:`v4l2_mbus_framefmt` for details. * - __u32 - - ``reserved``\ [8] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [7] - Reserved for future extensions. Applications and drivers must set the array to zero. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst index d7fe7543c506..842f962d2aea 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst @@ -90,7 +90,10 @@ the same sub-device is not defined. - ``interval`` - Period, in seconds, between consecutive video frames. * - __u32 - - ``reserved``\ [9] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [8] - Reserved for future extensions. Applications and drivers must set the array to zero. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst new file mode 100644 index 000000000000..68ca343c3b44 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst @@ -0,0 +1,147 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_SUBDEV_G_ROUTING: + +****************************************************** +ioctl VIDIOC_SUBDEV_G_ROUTING, VIDIOC_SUBDEV_S_ROUTING +****************************************************** + +Name +==== + +VIDIOC_SUBDEV_G_ROUTING - VIDIOC_SUBDEV_S_ROUTING - Get or set routing between streams of media pads in a media entity. + + +Synopsis +======== + +.. c:macro:: VIDIOC_SUBDEV_G_ROUTING + +``int ioctl(int fd, VIDIOC_SUBDEV_G_ROUTING, struct v4l2_subdev_routing *argp)`` + +.. c:macro:: VIDIOC_SUBDEV_S_ROUTING + +``int ioctl(int fd, VIDIOC_SUBDEV_S_ROUTING, struct v4l2_subdev_routing *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``argp`` + Pointer to struct :c:type:`v4l2_subdev_routing`. + + +Description +=========== + +These ioctls are used to get and set the routing in a media entity. +The routing configuration determines the flows of data inside an entity. + +Drivers report their current routing tables using the +``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes +with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and +setting or clearing flags of the ``flags`` field of a +struct :c:type:`v4l2_subdev_route`. + +All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This +means that the userspace must reconfigure all streams after calling the ioctl +with e.g. ``VIDIOC_SUBDEV_S_FMT``. + +Only subdevices which have both sink and source pads can support routing. + +When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application +provided ``num_routes`` is not big enough to contain all the available routes +the subdevice exposes, drivers return the ENOSPC error code and adjust the +value of the ``num_routes`` field. Application should then reserve enough memory +for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again. + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + +.. c:type:: v4l2_subdev_routing + +.. flat-table:: struct v4l2_subdev_routing + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``which`` + - Format to modified, from enum + :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. + * - struct :c:type:`v4l2_subdev_route` + - ``routes[]`` + - Array of struct :c:type:`v4l2_subdev_route` entries + * - __u32 + - ``num_routes`` + - Number of entries of the routes array + * - __u32 + - ``reserved``\ [5] + - Reserved for future extensions. Applications and drivers must set + the array to zero. + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + +.. c:type:: v4l2_subdev_route + +.. flat-table:: struct v4l2_subdev_route + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``sink_pad`` + - Sink pad number. + * - __u32 + - ``sink_stream`` + - Sink pad stream number. + * - __u32 + - ``source_pad`` + - Source pad number. + * - __u32 + - ``source_stream`` + - Source pad stream number. + * - __u32 + - ``flags`` + - Route enable/disable flags + :ref:`v4l2_subdev_routing_flags <v4l2-subdev-routing-flags>`. + * - __u32 + - ``reserved``\ [5] + - Reserved for future extensions. Applications and drivers must set + the array to zero. + +.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| + +.. _v4l2-subdev-routing-flags: + +.. flat-table:: enum v4l2_subdev_routing_flags + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - 0 + - The route is enabled. Set by applications. + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +ENOSPC + The application provided ``num_routes`` is not big enough to contain + all the available routes the subdevice exposes. + +EINVAL + The sink or source pad identifiers reference a non-existing pad, or reference + pads of different types (ie. the sink_pad identifiers refers to a source pad) + or the sink or source stream identifiers reference a non-existing stream on + the sink or source pad. + +E2BIG + The application provided ``num_routes`` for ``VIDIOC_SUBDEV_S_ROUTING`` is + larger than the number of routes the driver can handle. diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst index f9172a42f036..6b629c19168c 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst @@ -94,7 +94,10 @@ Selection targets and flags are documented in - ``r`` - Selection rectangle, in pixels. * - __u32 - - ``reserved``\ [8] + - ``stream`` + - Stream identifier. + * - __u32 + - ``reserved``\ [7] - Reserved for future extensions. Applications and drivers must set the array to zero. |