linux-toradex.git/Documentation/userspace-api/media/v4l, branch master

media: rppx1: Add framework to support Dreamchip RPPX1 ISP

2026-07-30T17:51:35+00:00

Add a framework driver for Dreamchip RPPX1 ISP. The driver aims to
provide a framework for other V4L2 based drivers to drive the RPPX1
functionality. The reason for this split is that the RPPX1 IP itself do
not provide any DMA engines to drive data to/from the device, instead it
depends on other IP blocks to implement these features.

While the peripherals around the RPPX1 ISP used in different designs and
by different vendors are different the RPPX1 core itself is the same.
For this reason the framework solution to be able to split the Dreamchip
RPPX1 driver from vendors usage of it have been picked in hope to reduce
duplication of the common parts.

The design is to try and keep the surface of this framework as small as
possible. The intention of this change is to be able to fill all needs
of this.

  * Two functions to create and destroy a RPPX1 instance, rppx1_create()
    and rppx1_destory(). These are intended to be called in the users
    probe and remove code paths.

  * Two functions to start and stop the RPPX1 processing, rppx1_start()
    and rppx1_stop(). These are intended to be called in the users
    stream on and stream off code paths.

  * One function to ask the RPPX1 to process parameters buffer prepared
    by user space, rppx1_params(). The intention is to call this
    function when the parameter buffer is queued to the V4L2 driver and
    the result stored by the driver until the time it needs to be
    written to the RPPX1. It's the users responsibility to write it
    either using MMIO or other means.

  * One function to fill in a statistic buffer based on the current
    status of the RPPX1, rppx1_stats_fill_isr(). The intention is that
    the user call's this in its interrupt handler when it knows the
    RPPX1 is done processing a frame.

  * One function to ack and retrieve the interrupts generated by the
    RPPX1, rppx1_interrupt(). The intention is to call this function
    when the users interrupt handler detects the RPPX1 have raised and
    interrupt. There is no need for the user to understand, or act, on
    the actual RPPX1 interrupt, but it can if it wants too.

The initial support in the framework is limited and do not implement any
ISP processing algorithms other then configuring the RPPX1 to process
any Bayer (8-, 10, or 12-bit) image and produce either a RGB or YUYV
output. It do however probe all function blocks of the RPPX1 and provide
an interface to interact with both parameter and statistic bufferers.
The user of the framework will not change as algorithms for the
different function blocks of the ISP are being added.

Signed-off-by: Niklas Söderlund 
Co-developed-by: Jai Luthra 
Signed-off-by: Jai Luthra 
Co-developed-by: Jacopo Mondi 
Signed-off-by: Jacopo Mondi 
Reviewed-by: Jacopo Mondi 
Signed-off-by: Sakari Ailus

media: Documentation: uapi: Update V4L2 ISP for extensible stats

2026-07-30T17:51:12+00:00

Rework the userspace-api documentation of V4L2 ISP to support
statistics.

Update all occurences of 'v4l2_isp_param' types to match the uAPI
changes and add a section to document the statistics serialization
format.

Signed-off-by: Antoine Bouyer 
Reviewed-by: Niklas Söderlund 
[Update on uAPI changes]
Signed-off-by: Jacopo Mondi 
Signed-off-by: Sakari Ailus

Documentation: media: fix spelling errors

2026-07-28T14:48:10+00:00

Fix spelling errors reported by codespell:

  thare -> there  (vidioc-subdev-g-routing.rst)
  stuct -> struct (legacy_dvb_video.rst)

No functional change.

Signed-off-by: shaikh.kamal 
Signed-off-by: Hans Verkuil

media: v4l2-ctrls: Allow unknown HDR10 white point and luminance

2026-07-28T13:17:54+00:00

SMPTE ST 2086 defines the nominal ranges for mastering display
chromaticity and luminance values. Its Annex A also documents that
CTA 861-G uses zero maximum and minimum luminance values to signal
that the corresponding values are unknown, and the xy chromaticity
coordinate (0, 0) to signal that the white point chromaticity is
unknown.

The V4L2 HDR10 mastering display compound control currently rejects
these values. Consequently, an unknown white point or luminance value
prevents the entire compound control from being updated, making the
other valid mastering display metadata unavailable to userspace.

Accept (0, 0) as an unknown white point and zero as an unknown maximum
or minimum mastering luminance. Continue to reject partially zero white
point coordinates and non-zero values outside the nominal ranges.
Display primary validation remains unchanged.

Document the newly accepted unknown values in the V4L2 userspace API.

Fixes: 1ad0de78e794 ("media: v4l: Add HDR10 static metadata controls")
Cc: stable@vger.kernel.org
Signed-off-by: Ming Qian 
Signed-off-by: Hans Verkuil

Documentation: media: vidioc-g-ext-ctrls: clarify try/set behavior

2026-07-17T08:13:44+00:00

It was not clearly stated in the documentation that calling
VIDIOC_S_EXT_CTRLS implies an internal VIDIOC_TRY_EXT_CTRLS
call.

Clarify this.

Signed-off-by: Hans Verkuil 
Acked-by: Linus Walleij 
Link: https://lore.kernel.org/linux-media/20260701-v4l2-doc-v1-1-9cce64b7a1c2@kernel.org/
Signed-off-by: Mauro Carvalho Chehab

media: Documentation: Improve LINK_FREQ documentation

2026-05-07T10:23:47+00:00

Add a reference to the LINK_FREQ control and clarify the meaning of the
control as for C-PHY the matter is less obvious.

Signed-off-by: Sakari Ailus 
Reviewed-by: Mirela Rabulea 
Reviewed-by: Jacopo Mondi 
Reviewed-by: Laurent Pinchart

media: v4l2-controls: Add control for background detection

2026-05-04T06:35:14+00:00

Add a generic V4L2 boolean control V4L2_CID_MPEG_VIDEO_BACKGROUND_DETECTION
that allows encoders to detect background regions in a frame and use fewer
bits or skip mode to encode them, potentially reducing bitrate for streams
with stationary scenes.

Signed-off-by: Jackson Lee 
Signed-off-by: Nas Chung 
Reviewed-by: Nicolas Dufresne 
Signed-off-by: Nicolas Dufresne 
Signed-off-by: Hans Verkuil

Documentation: media: Fix v4l2_vp9_segmentation

2026-05-04T06:35:14+00:00

feature_data is defined as __s16 in the header.

Signed-off-by: Fritz Koenig 
Reviewed-by: Nicolas Dufresne 
Signed-off-by: Nicolas Dufresne 
Signed-off-by: Hans Verkuil

media: uapi: Clarify MBUS color component order for serial buses

2026-03-24T10:58:02+00:00

The subdev format documentation has a subsection describing how to use
the media bus pixel codes for serial buses. While it describes the
sampling part well, it doesn't really describe the current convention
used for the components order.

Let's improve that.

Reviewed-by: Laurent Pinchart 
Signed-off-by: Maxime Ripard 
Signed-off-by: Sakari Ailus 
Signed-off-by: Hans Verkuil

Merge tag 'media/v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

2026-02-11T20:20:25+00:00

Pull media updates from Mauro Carvalho Chehab:

 - Add support for GMSL1 and GMSL‑coax modules (PCI mgb4)

 - Add driver for TI VIP

 - AV1 – first kernel support (pixel‑format, decoder, transcoder)

 - Three new camera‑sensor drivers (os05b10, s5k3m5, s5kjn1)

 - Synopsys CSI‑2 receiver driver

 - Verisilicon & rkvdec – major fixes and enhancements

 - IPU6 (and 7) fixes and preparation for metadata

 - omap3isp: v4l2-compliance updates

 - Fix DVB streaming, drop wait_prepare/finish (dvb/vb2)

* tag 'media/v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (307 commits)
  media: uvcvideo: Pass allocation size directly to uvc_alloc_urb_buffer
  media: uvcvideo: Fix allocation for small frame sizes
  media: uvcvideo: Return queued buffers on start_streaming() failure
  media: uvcvideo: Create an ID namespace for streaming output terminals
  media: rkvdec: Add HEVC support for the VDPU383 variant
  media: rkvdec: Add HEVC support for the VDPU381 variant
  media: rkvdec: Add H264 support for the VDPU383 variant
  media: rkvdec: Add H264 support for the VDPU381 variant
  media: rkvdec: Disable multicore support
  media: rkvdec: Enable all clocks without naming them
  media: rkvdec: Support per-variant interrupt handler
  media: rkvdec: Add RCB and SRAM support
  media: rkvdec: Add variant specific coded formats list
  media: rkvdec: Move hevc functions to common file
  media: rkvdec: Move h264 functions to common file
  media: rkvdec: Use structs to represent the HW RPS
  media: rkvdec: Move cabac tables to their own source file
  media: rkvdec: Switch to using structs instead of writel
  media: visl: Add HEVC short and long term RPS sets
  media: v4l2-ctrls: Add hevc_ext_sps_[ls]t_rps controls
  ...