Document how embedded data support should be implemented for camera sensors, and when and how CCS embedded data format should be referenced. Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> Reviewed-by: Julien Massot <julien.massot@xxxxxxxxxxxxx> --- .../media/drivers/camera-sensor.rst | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/Documentation/userspace-api/media/drivers/camera-sensor.rst b/Documentation/userspace-api/media/drivers/camera-sensor.rst index 919a50e8b9d9..9f3b0da3ad0d 100644 --- a/Documentation/userspace-api/media/drivers/camera-sensor.rst +++ b/Documentation/userspace-api/media/drivers/camera-sensor.rst @@ -102,3 +102,24 @@ register programming sequences shall initialize the :ref:`V4L2_CID_HFLIP values programmed by the register sequences. The default values of these controls shall be 0 (disabled). Especially these controls shall not be inverted, independently of the sensor's mounting rotation. + +Embedded data +------------- + +Many sensors, mostly raw sensors, support embedded data which is used to convey +the sensor configuration for the captured frame back to the host. While CSI-2 is +the most common data interface used by such sensors, embedded data can be +available on other interfaces as well. + +Such sensors expose two internal sink pads (pads that have both the +``MEDIA_PAD_FL_SINK <MEDIA-PAD-FL-SINK>`` and ``MEDIA_PAD_FL_INTERNAL +<MEDIA-PAD-FL-INTERNAL>`` flags set) to model the source of the image and +embedded data streams. Both of these pads produces a single stream, and the +sub-device routes those streams to the external (source) pad. If the sub-device +driver supports disabling embedded data, this can be done by disabling the +embedded data route via the ``VIDIOC_SUBDEV_S_ROUTING`` IOCTL. + +In general, changing the embedded data format from the driver-configured values +is not supported. The height of the metadata is device-specific and the width +is that (or less of that) of the image width, as configured on the pixel data +stream. -- 2.39.2
