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author | Sakari Ailus <sakari.ailus@linux.intel.com> | 2023-03-28 15:54:59 +0300 |
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committer | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2023-05-25 17:21:21 +0300 |
commit | 71511a24eeec900b1a7e81b5f141c95313624ade (patch) | |
tree | 662b6e815a9ee411ca129c7cddd26f02726943b3 /Documentation/driver-api/media | |
parent | a73206f33bd1e7f9c7579a0555e2ad634455fddf (diff) | |
download | linux-71511a24eeec900b1a7e81b5f141c95313624ade.tar.xz |
Documentation: v4l: Document rotation and orientation for sensor drivers
Document how rotation and orientation should be taken into account in
writing camera sensor drivers.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Diffstat (limited to 'Documentation/driver-api/media')
-rw-r--r-- | Documentation/driver-api/media/camera-sensor.rst | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/driver-api/media/camera-sensor.rst b/Documentation/driver-api/media/camera-sensor.rst index c7d4891bd24e..93f4f2536c25 100644 --- a/Documentation/driver-api/media/camera-sensor.rst +++ b/Documentation/driver-api/media/camera-sensor.rst @@ -151,3 +151,25 @@ used to obtain device's power state after the power state transition: The function returns a non-zero value if it succeeded getting the power count or runtime PM was disabled, in either of which cases the driver may proceed to access the device. + +Rotation, orientation and flipping +---------------------------------- + +Some systems have the camera sensor mounted upside down compared to its natural +mounting rotation. In such cases, drivers shall expose the information to +userspace with the :ref:`V4L2_CID_CAMERA_SENSOR_ROTATION +<v4l2-camera-sensor-rotation>` control. + +Sensor drivers shall also report the sensor's mounting orientation with the +:ref:`V4L2_CID_CAMERA_SENSOR_ORIENTATION <v4l2-camera-sensor-orientation>`. + +Use ``v4l2_fwnode_device_parse()`` to obtain rotation and orientation +information from system firmware and ``v4l2_ctrl_new_fwnode_properties()`` to +register the appropriate controls. + +Sensor drivers that have any vertical or horizontal flips embedded in the +register programming sequences shall initialize the V4L2_CID_HFLIP and +V4L2_CID_VFLIP controls with the 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. |