diff options
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/driver-model/devres.rst | 1 | ||||
| -rw-r--r-- | Documentation/driver-api/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/driver-api/media/camera-sensor.rst | 22 | ||||
| -rw-r--r-- | Documentation/driver-api/wmi.rst | 21 |
4 files changed, 45 insertions, 0 deletions
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index 4249eb4239e0..8be086b3f829 100644 --- a/Documentation/driver-api/driver-model/devres.rst +++ b/Documentation/driver-api/driver-model/devres.rst @@ -364,6 +364,7 @@ MEM devm_kmalloc_array() devm_kmemdup() devm_krealloc() + devm_krealloc_array() devm_kstrdup() devm_kstrdup_const() devm_kvasprintf() diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index ff9aa1afdc62..1e16a40da3ba 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -113,6 +113,7 @@ available subsections can be seen below. xillybus zorro hte/index + wmi .. only:: subproject and html 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. diff --git a/Documentation/driver-api/wmi.rst b/Documentation/driver-api/wmi.rst new file mode 100644 index 000000000000..6ca58c8249e5 --- /dev/null +++ b/Documentation/driver-api/wmi.rst @@ -0,0 +1,21 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +============== +WMI Driver API +============== + +The WMI driver core supports a more modern bus-based interface for interacting +with WMI devices, and an older GUID-based interface. The latter interface is +considered to be deprecated, so new WMI drivers should generally avoid it since +it has some issues with multiple WMI devices and events sharing the same GUIDs +and/or notification IDs. The modern bus-based interface instead maps each +WMI device to a :c:type:`struct wmi_device <wmi_device>`, so it supports +WMI devices sharing GUIDs and/or notification IDs. Drivers can then register +a :c:type:`struct wmi_driver <wmi_driver>`, which will be bound to compatible +WMI devices by the driver core. + +.. kernel-doc:: include/linux/wmi.h + :internal: + +.. kernel-doc:: drivers/platform/x86/wmi.c + :export: |