From 71511a24eeec900b1a7e81b5f141c95313624ade Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Tue, 28 Mar 2023 15:54:59 +0300 Subject: 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 Reviewed-by: Jacopo Mondi Signed-off-by: Hans Verkuil --- Documentation/driver-api/media/camera-sensor.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'Documentation/driver-api') 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 +` control. + +Sensor drivers shall also report the sensor's mounting orientation with the +:ref:`V4L2_CID_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. -- cgit v1.2.3