[PATCH v2 02/10] media: v4l2-ctrl: Document V4L2_CID_CAMERA_SENSOR_LOCATION

[Jacopo Mondi <jacopo@jmondi.org>]

Add documentation for the V4L2_CID_CAMERA_SENSOR_LOCATION camera
control. The newly added read-only control reports the camera device
mounting position.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 .../media/uapi/v4l/ext-ctrls-camera.rst       | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/Documentation/media/uapi/v4l/ext-ctrls-camera.rst b/Documentation/media/uapi/v4l/ext-ctrls-camera.rst
index 51c1d5c9eb00..ecf151f3f0f4 100644
--- a/Documentation/media/uapi/v4l/ext-ctrls-camera.rst
+++ b/Documentation/media/uapi/v4l/ext-ctrls-camera.rst
@@ -510,6 +510,40 @@ enum v4l2_scene_mode -
     value down. A value of zero stops the motion if one is in progress
     and has no effect otherwise.
 
+``V4L2_CID_CAMERA_SENSOR_LOCATION (integer)``
+    This read-only control describes the camera sensor location by
+    reporting its mounting position on the device where the camera is
+    installed. The control value is constant and not modifiable by software
+    and its value is retrieved from the firmware interface by parsing the
+    'location' property. This control is particularly meaningful for
+    devices which have a well defined orientation, such as phones, laptops
+    and portable devices as the camera location is expressed as a position
+    relative to the device intended usage orientation. In example, a camera
+    sensor installed on the user-facing side of a phone, a tablet or a
+    laptop device is said to be installed in the ``V4L2_LOCATION_FRONT``
+    location while camera sensors installed on the side opposed to the
+    front one are said to be installed in the ``V4L2_LOCATION_BACK``
+    location. Camera sensors connected to the device by extension cables
+    which are freely movable regardless of the device orientation, such as
+    webcams and digital cameras, are said to be have
+    ``V4L2_LOCATION_EXTERNAL`` location.
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_LOCATION_FRONT``
+      - The camera sensor is located on the front side of the device.
+    * - ``V4L2_LOCATION_BACK``
+      - The camera sensor is located on the back side of the device.
+    * - ``V4L2_LOCATION_EXTERNAL``
+      - The camera sensor is connected by extension cables to the device and
+        it's freely movable.
+
+
+
 .. [#f1]
    This control may be changed to a menu control in the future, if more
    options are required.
-- 
2.23.0