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| author | Jacopo Mondi <jacopo@jmondi.org> | 2022-11-03 17:17:51 +0100 |
|---|---|---|
| committer | Jacopo Mondi <jacopo@jmondi.org> | 2022-11-23 18:44:35 +0100 |
| commit | 29d6d0e93b0193b70c6c0564eb424f2b6accf4a8 (patch) | |
| tree | 65baf0ad8f0f39d89ce185cc6b6f6251b5312d03 /Documentation/sensor_driver_requirements.rst | |
| parent | a857a150e13d71abdc0b321984f08bd0a173a3b2 (diff) | |
libcamera: Move IPA sensor controls validation to CameraSensor
The CameraSensor class validates that the sensor driver in use supports
the controls required for IPA modules to work correctly.
For in-tree IPA modules, whose pipeline handlers already use
CameraSensor there's no need to validate such controls again.
Remove controls validation from the IPU3 and RkISP1 IPA modules and rely
on CameraSensor doing that at initialization time.
The list of mandatory controls is expanded to add V4L2_CID_ANALOGUE_GAIN
without which IPA modules cannot function.
The new requirement only applies to RAW sensors, platforms like UVC and
Simple are not impacted by this change.
While at it, expand the sensor driver requirements documentation to
include V4L2_ANALOGUE_GAIN in the list of mandatory controls a sensor
driver has to support.
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Diffstat (limited to 'Documentation/sensor_driver_requirements.rst')
| -rw-r--r-- | Documentation/sensor_driver_requirements.rst | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/sensor_driver_requirements.rst b/Documentation/sensor_driver_requirements.rst index b0854be3..3abc8f35 100644 --- a/Documentation/sensor_driver_requirements.rst +++ b/Documentation/sensor_driver_requirements.rst @@ -24,16 +24,23 @@ The sensor driver is assumed to be fully compliant with the V4L2 specification. For RAW sensors, the sensor driver shall support the following V4L2 controls: +* `V4L2_CID_ANALOGUE_GAIN`_ * `V4L2_CID_EXPOSURE`_ * `V4L2_CID_HBLANK`_ * `V4L2_CID_PIXEL_RATE`_ * `V4L2_CID_VBLANK`_ +.. _V4L2_CID_ANALOGUE_GAIN: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html .. _V4L2_CID_EXPOSURE: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/control.html .. _V4L2_CID_HBLANK: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html .. _V4L2_CID_PIXEL_RATE: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-process.html .. _V4L2_CID_VBLANK: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html +The ``ANALOGUE_GAIN`` control units are sensor-specific. libcamera requires +a sensor-specific CameraSensorHelper implementation to translate between the +sensor specific ``gain code`` and the analogue ``gain value`` expressed as an +absolute number as defined by ``controls::AnalogueGain``. + While V4L2 doesn't specify a unit for the ``EXPOSURE`` control, libcamera requires it to be expressed as a number of image lines. Camera sensor drivers that do not comply with this requirement will need to be adapted or will produce |