Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 674 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-camera.rst
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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _camera-controls:
+
+************************
+Camera Control Reference
+************************
+
+The Camera class includes controls for mechanical (or equivalent
+digital) features of a device such as controllable lenses or sensors.
+
+
+.. _camera-control-id:
+
+Camera Control IDs
+==================
+
+``V4L2_CID_CAMERA_CLASS (class)``
+    The Camera class descriptor. Calling
+    :ref:`VIDIOC_QUERYCTRL` for this control will
+    return a description of this control class.
+
+.. _v4l2-exposure-auto-type:
+
+``V4L2_CID_EXPOSURE_AUTO``
+    (enum)
+
+enum v4l2_exposure_auto_type -
+    Enables automatic adjustments of the exposure time and/or iris
+    aperture. The effect of manual changes of the exposure time or iris
+    aperture while these features are enabled is undefined, drivers
+    should ignore such requests. Possible values are:
+
+
+.. tabularcolumns:: |p{7.1cm}|p{10.4cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_EXPOSURE_AUTO``
+      - Automatic exposure time, automatic iris aperture.
+    * - ``V4L2_EXPOSURE_MANUAL``
+      - Manual exposure time, manual iris.
+    * - ``V4L2_EXPOSURE_SHUTTER_PRIORITY``
+      - Manual exposure time, auto iris.
+    * - ``V4L2_EXPOSURE_APERTURE_PRIORITY``
+      - Auto exposure time, manual iris.
+
+
+
+``V4L2_CID_EXPOSURE_ABSOLUTE (integer)``
+    Determines the exposure time of the camera sensor. The exposure time
+    is limited by the frame interval. Drivers should interpret the
+    values as 100 µs units, where the value 1 stands for 1/10000th of a
+    second, 10000 for 1 second and 100000 for 10 seconds.
+
+``V4L2_CID_EXPOSURE_AUTO_PRIORITY (boolean)``
+    When ``V4L2_CID_EXPOSURE_AUTO`` is set to ``AUTO`` or
+    ``APERTURE_PRIORITY``, this control determines if the device may
+    dynamically vary the frame rate. By default this feature is disabled
+    (0) and the frame rate must remain constant.
+
+``V4L2_CID_AUTO_EXPOSURE_BIAS (integer menu)``
+    Determines the automatic exposure compensation, it is effective only
+    when ``V4L2_CID_EXPOSURE_AUTO`` control is set to ``AUTO``,
+    ``SHUTTER_PRIORITY`` or ``APERTURE_PRIORITY``. It is expressed in
+    terms of EV, drivers should interpret the values as 0.001 EV units,
+    where the value 1000 stands for +1 EV.
+
+    Increasing the exposure compensation value is equivalent to
+    decreasing the exposure value (EV) and will increase the amount of
+    light at the image sensor. The camera performs the exposure
+    compensation by adjusting absolute exposure time and/or aperture.
+
+.. _v4l2-exposure-metering:
+
+``V4L2_CID_EXPOSURE_METERING``
+    (enum)
+
+enum v4l2_exposure_metering -
+    Determines how the camera measures the amount of light available for
+    the frame exposure. Possible values are:
+
+.. tabularcolumns:: |p{8.7cm}|p{8.7cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_EXPOSURE_METERING_AVERAGE``
+      - Use the light information coming from the entire frame and average
+	giving no weighting to any particular portion of the metered area.
+    * - ``V4L2_EXPOSURE_METERING_CENTER_WEIGHTED``
+      - Average the light information coming from the entire frame giving
+	priority to the center of the metered area.
+    * - ``V4L2_EXPOSURE_METERING_SPOT``
+      - Measure only very small area at the center of the frame.
+    * - ``V4L2_EXPOSURE_METERING_MATRIX``
+      - A multi-zone metering. The light intensity is measured in several
+	points of the frame and the results are combined. The algorithm of
+	the zones selection and their significance in calculating the
+	final value is device dependent.
+
+
+
+``V4L2_CID_PAN_RELATIVE (integer)``
+    This control turns the camera horizontally by the specified amount.
+    The unit is undefined. A positive value moves the camera to the
+    right (clockwise when viewed from above), a negative value to the
+    left. A value of zero does not cause motion. This is a write-only
+    control.
+
+``V4L2_CID_TILT_RELATIVE (integer)``
+    This control turns the camera vertically by the specified amount.
+    The unit is undefined. A positive value moves the camera up, a
+    negative value down. A value of zero does not cause motion. This is
+    a write-only control.
+
+``V4L2_CID_PAN_RESET (button)``
+    When this control is set, the camera moves horizontally to the
+    default position.
+
+``V4L2_CID_TILT_RESET (button)``
+    When this control is set, the camera moves vertically to the default
+    position.
+
+``V4L2_CID_PAN_ABSOLUTE (integer)``
+    This control turns the camera horizontally to the specified
+    position. Positive values move the camera to the right (clockwise
+    when viewed from above), negative values to the left. Drivers should
+    interpret the values as arc seconds, with valid values between -180
+    * 3600 and +180 * 3600 inclusive.
+
+``V4L2_CID_TILT_ABSOLUTE (integer)``
+    This control turns the camera vertically to the specified position.
+    Positive values move the camera up, negative values down. Drivers
+    should interpret the values as arc seconds, with valid values
+    between -180 * 3600 and +180 * 3600 inclusive.
+
+``V4L2_CID_FOCUS_ABSOLUTE (integer)``
+    This control sets the focal point of the camera to the specified
+    position. The unit is undefined. Positive values set the focus
+    closer to the camera, negative values towards infinity.
+
+``V4L2_CID_FOCUS_RELATIVE (integer)``
+    This control moves the focal point of the camera by the specified
+    amount. The unit is undefined. Positive values move the focus closer
+    to the camera, negative values towards infinity. This is a
+    write-only control.
+
+``V4L2_CID_FOCUS_AUTO (boolean)``
+    Enables continuous automatic focus adjustments. The effect of manual
+    focus adjustments while this feature is enabled is undefined,
+    drivers should ignore such requests.
+
+``V4L2_CID_AUTO_FOCUS_START (button)``
+    Starts single auto focus process. The effect of setting this control
+    when ``V4L2_CID_FOCUS_AUTO`` is set to ``TRUE`` (1) is undefined,
+    drivers should ignore such requests.
+
+``V4L2_CID_AUTO_FOCUS_STOP (button)``
+    Aborts automatic focusing started with ``V4L2_CID_AUTO_FOCUS_START``
+    control. It is effective only when the continuous autofocus is
+    disabled, that is when ``V4L2_CID_FOCUS_AUTO`` control is set to
+    ``FALSE`` (0).
+
+.. _v4l2-auto-focus-status:
+
+``V4L2_CID_AUTO_FOCUS_STATUS (bitmask)``
+    The automatic focus status. This is a read-only control.
+
+    Setting ``V4L2_LOCK_FOCUS`` lock bit of the ``V4L2_CID_3A_LOCK``
+    control may stop updates of the ``V4L2_CID_AUTO_FOCUS_STATUS``
+    control value.
+
+.. tabularcolumns:: |p{6.8cm}|p{10.7cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_AUTO_FOCUS_STATUS_IDLE``
+      - Automatic focus is not active.
+    * - ``V4L2_AUTO_FOCUS_STATUS_BUSY``
+      - Automatic focusing is in progress.
+    * - ``V4L2_AUTO_FOCUS_STATUS_REACHED``
+      - Focus has been reached.
+    * - ``V4L2_AUTO_FOCUS_STATUS_FAILED``
+      - Automatic focus has failed, the driver will not transition from
+	this state until another action is performed by an application.
+
+
+
+.. _v4l2-auto-focus-range:
+
+``V4L2_CID_AUTO_FOCUS_RANGE``
+    (enum)
+
+enum v4l2_auto_focus_range -
+    Determines auto focus distance range for which lens may be adjusted.
+
+.. tabularcolumns:: |p{6.9cm}|p{10.6cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_AUTO_FOCUS_RANGE_AUTO``
+      - The camera automatically selects the focus range.
+    * - ``V4L2_AUTO_FOCUS_RANGE_NORMAL``
+      - Normal distance range, limited for best automatic focus
+	performance.
+    * - ``V4L2_AUTO_FOCUS_RANGE_MACRO``
+      - Macro (close-up) auto focus. The camera will use its minimum
+	possible distance for auto focus.
+    * - ``V4L2_AUTO_FOCUS_RANGE_INFINITY``
+      - The lens is set to focus on an object at infinite distance.
+
+
+
+``V4L2_CID_ZOOM_ABSOLUTE (integer)``
+    Specify the objective lens focal length as an absolute value. The
+    zoom unit is driver-specific and its value should be a positive
+    integer.
+
+``V4L2_CID_ZOOM_RELATIVE (integer)``
+    Specify the objective lens focal length relatively to the current
+    value. Positive values move the zoom lens group towards the
+    telephoto direction, negative values towards the wide-angle
+    direction. The zoom unit is driver-specific. This is a write-only
+    control.
+
+``V4L2_CID_ZOOM_CONTINUOUS (integer)``
+    Move the objective lens group at the specified speed until it
+    reaches physical device limits or until an explicit request to stop
+    the movement. A positive value moves the zoom lens group towards the
+    telephoto direction. A value of zero stops the zoom lens group
+    movement. A negative value moves the zoom lens group towards the
+    wide-angle direction. The zoom speed unit is driver-specific.
+
+``V4L2_CID_IRIS_ABSOLUTE (integer)``
+    This control sets the camera's aperture to the specified value. The
+    unit is undefined. Larger values open the iris wider, smaller values
+    close it.
+
+``V4L2_CID_IRIS_RELATIVE (integer)``
+    This control modifies the camera's aperture by the specified amount.
+    The unit is undefined. Positive values open the iris one step
+    further, negative values close it one step further. This is a
+    write-only control.
+
+``V4L2_CID_PRIVACY (boolean)``
+    Prevent video from being acquired by the camera. When this control
+    is set to ``TRUE`` (1), no image can be captured by the camera.
+    Common means to enforce privacy are mechanical obturation of the
+    sensor and firmware image processing, but the device is not
+    restricted to these methods. Devices that implement the privacy
+    control must support read access and may support write access.
+
+``V4L2_CID_BAND_STOP_FILTER (integer)``
+    Switch the band-stop filter of a camera sensor on or off, or specify
+    its strength. Such band-stop filters can be used, for example, to
+    filter out the fluorescent light component.
+
+.. _v4l2-auto-n-preset-white-balance:
+
+``V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE``
+    (enum)
+
+enum v4l2_auto_n_preset_white_balance -
+    Sets white balance to automatic, manual or a preset. The presets
+    determine color temperature of the light as a hint to the camera for
+    white balance adjustments resulting in most accurate color
+    representation. The following white balance presets are listed in
+    order of increasing color temperature.
+
+.. tabularcolumns:: |p{7.4cm}|p{10.1cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_WHITE_BALANCE_MANUAL``
+      - Manual white balance.
+    * - ``V4L2_WHITE_BALANCE_AUTO``
+      - Automatic white balance adjustments.
+    * - ``V4L2_WHITE_BALANCE_INCANDESCENT``
+      - White balance setting for incandescent (tungsten) lighting. It
+	generally cools down the colors and corresponds approximately to
+	2500...3500 K color temperature range.
+    * - ``V4L2_WHITE_BALANCE_FLUORESCENT``
+      - White balance preset for fluorescent lighting. It corresponds
+	approximately to 4000...5000 K color temperature.
+    * - ``V4L2_WHITE_BALANCE_FLUORESCENT_H``
+      - With this setting the camera will compensate for fluorescent H
+	lighting.
+    * - ``V4L2_WHITE_BALANCE_HORIZON``
+      - White balance setting for horizon daylight. It corresponds
+	approximately to 5000 K color temperature.
+    * - ``V4L2_WHITE_BALANCE_DAYLIGHT``
+      - White balance preset for daylight (with clear sky). It corresponds
+	approximately to 5000...6500 K color temperature.
+    * - ``V4L2_WHITE_BALANCE_FLASH``
+      - With this setting the camera will compensate for the flash light.
+	It slightly warms up the colors and corresponds roughly to
+	5000...5500 K color temperature.
+    * - ``V4L2_WHITE_BALANCE_CLOUDY``
+      - White balance preset for moderately overcast sky. This option
+	corresponds approximately to 6500...8000 K color temperature
+	range.
+    * - ``V4L2_WHITE_BALANCE_SHADE``
+      - White balance preset for shade or heavily overcast sky. It
+	corresponds approximately to 9000...10000 K color temperature.
+
+
+
+.. _v4l2-wide-dynamic-range:
+
+``V4L2_CID_WIDE_DYNAMIC_RANGE (boolean)``
+    Enables or disables the camera's wide dynamic range feature. This
+    feature allows to obtain clear images in situations where intensity
+    of the illumination varies significantly throughout the scene, i.e.
+    there are simultaneously very dark and very bright areas. It is most
+    commonly realized in cameras by combining two subsequent frames with
+    different exposure times.  [#f1]_
+
+.. _v4l2-image-stabilization:
+
+``V4L2_CID_IMAGE_STABILIZATION (boolean)``
+    Enables or disables image stabilization.
+
+``V4L2_CID_ISO_SENSITIVITY (integer menu)``
+    Determines ISO equivalent of an image sensor indicating the sensor's
+    sensitivity to light. The numbers are expressed in arithmetic scale,
+    as per :ref:`iso12232` standard, where doubling the sensor
+    sensitivity is represented by doubling the numerical ISO value.
+    Applications should interpret the values as standard ISO values
+    multiplied by 1000, e.g. control value 800 stands for ISO 0.8.
+    Drivers will usually support only a subset of standard ISO values.
+    The effect of setting this control while the
+    ``V4L2_CID_ISO_SENSITIVITY_AUTO`` control is set to a value other
+    than ``V4L2_CID_ISO_SENSITIVITY_MANUAL`` is undefined, drivers
+    should ignore such requests.
+
+.. _v4l2-iso-sensitivity-auto-type:
+
+``V4L2_CID_ISO_SENSITIVITY_AUTO``
+    (enum)
+
+enum v4l2_iso_sensitivity_type -
+    Enables or disables automatic ISO sensitivity adjustments.
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_CID_ISO_SENSITIVITY_MANUAL``
+      - Manual ISO sensitivity.
+    * - ``V4L2_CID_ISO_SENSITIVITY_AUTO``
+      - Automatic ISO sensitivity adjustments.
+
+
+
+.. _v4l2-scene-mode:
+
+``V4L2_CID_SCENE_MODE``
+    (enum)
+
+enum v4l2_scene_mode -
+    This control allows to select scene programs as the camera automatic
+    modes optimized for common shooting scenes. Within these modes the
+    camera determines best exposure, aperture, focusing, light metering,
+    white balance and equivalent sensitivity. The controls of those
+    parameters are influenced by the scene mode control. An exact
+    behavior in each mode is subject to the camera specification.
+
+    When the scene mode feature is not used, this control should be set
+    to ``V4L2_SCENE_MODE_NONE`` to make sure the other possibly related
+    controls are accessible. The following scene programs are defined:
+
+.. raw:: latex
+
+    \small
+
+.. tabularcolumns:: |p{5.9cm}|p{11.6cm}|
+
+.. cssclass:: longtable
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_SCENE_MODE_NONE``
+      - The scene mode feature is disabled.
+    * - ``V4L2_SCENE_MODE_BACKLIGHT``
+      - Backlight. Compensates for dark shadows when light is coming from
+	behind a subject, also by automatically turning on the flash.
+    * - ``V4L2_SCENE_MODE_BEACH_SNOW``
+      - Beach and snow. This mode compensates for all-white or bright
+	scenes, which tend to look gray and low contrast, when camera's
+	automatic exposure is based on an average scene brightness. To
+	compensate, this mode automatically slightly overexposes the
+	frames. The white balance may also be adjusted to compensate for
+	the fact that reflected snow looks bluish rather than white.
+    * - ``V4L2_SCENE_MODE_CANDLELIGHT``
+      - Candle light. The camera generally raises the ISO sensitivity and
+	lowers the shutter speed. This mode compensates for relatively
+	close subject in the scene. The flash is disabled in order to
+	preserve the ambiance of the light.
+    * - ``V4L2_SCENE_MODE_DAWN_DUSK``
+      - Dawn and dusk. Preserves the colors seen in low natural light
+	before dusk and after down. The camera may turn off the flash, and
+	automatically focus at infinity. It will usually boost saturation
+	and lower the shutter speed.
+    * - ``V4L2_SCENE_MODE_FALL_COLORS``
+      - Fall colors. Increases saturation and adjusts white balance for
+	color enhancement. Pictures of autumn leaves get saturated reds
+	and yellows.
+    * - ``V4L2_SCENE_MODE_FIREWORKS``
+      - Fireworks. Long exposure times are used to capture the expanding
+	burst of light from a firework. The camera may invoke image
+	stabilization.
+    * - ``V4L2_SCENE_MODE_LANDSCAPE``
+      - Landscape. The camera may choose a small aperture to provide deep
+	depth of field and long exposure duration to help capture detail
+	in dim light conditions. The focus is fixed at infinity. Suitable
+	for distant and wide scenery.
+    * - ``V4L2_SCENE_MODE_NIGHT``
+      - Night, also known as Night Landscape. Designed for low light
+	conditions, it preserves detail in the dark areas without blowing
+	out bright objects. The camera generally sets itself to a
+	medium-to-high ISO sensitivity, with a relatively long exposure
+	time, and turns flash off. As such, there will be increased image
+	noise and the possibility of blurred image.
+    * - ``V4L2_SCENE_MODE_PARTY_INDOOR``
+      - Party and indoor. Designed to capture indoor scenes that are lit
+	by indoor background lighting as well as the flash. The camera
+	usually increases ISO sensitivity, and adjusts exposure for the
+	low light conditions.
+    * - ``V4L2_SCENE_MODE_PORTRAIT``
+      - Portrait. The camera adjusts the aperture so that the depth of
+	field is reduced, which helps to isolate the subject against a
+	smooth background. Most cameras recognize the presence of faces in
+	the scene and focus on them. The color hue is adjusted to enhance
+	skin tones. The intensity of the flash is often reduced.
+    * - ``V4L2_SCENE_MODE_SPORTS``
+      - Sports. Significantly increases ISO and uses a fast shutter speed
+	to freeze motion of rapidly-moving subjects. Increased image noise
+	may be seen in this mode.
+    * - ``V4L2_SCENE_MODE_SUNSET``
+      - Sunset. Preserves deep hues seen in sunsets and sunrises. It bumps
+	up the saturation.
+    * - ``V4L2_SCENE_MODE_TEXT``
+      - Text. It applies extra contrast and sharpness, it is typically a
+	black-and-white mode optimized for readability. Automatic focus
+	may be switched to close-up mode and this setting may also involve
+	some lens-distortion correction.
+
+.. raw:: latex
+
+    \normalsize
+
+
+``V4L2_CID_3A_LOCK (bitmask)``
+    This control locks or unlocks the automatic focus, exposure and
+    white balance. The automatic adjustments can be paused independently
+    by setting the corresponding lock bit to 1. The camera then retains
+    the settings until the lock bit is cleared. The following lock bits
+    are defined:
+
+    When a given algorithm is not enabled, drivers should ignore
+    requests to lock it and should return no error. An example might be
+    an application setting bit ``V4L2_LOCK_WHITE_BALANCE`` when the
+    ``V4L2_CID_AUTO_WHITE_BALANCE`` control is set to ``FALSE``. The
+    value of this control may be changed by exposure, white balance or
+    focus controls.
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_LOCK_EXPOSURE``
+      - Automatic exposure adjustments lock.
+    * - ``V4L2_LOCK_WHITE_BALANCE``
+      - Automatic white balance adjustments lock.
+    * - ``V4L2_LOCK_FOCUS``
+      - Automatic focus lock.
+
+
+
+``V4L2_CID_PAN_SPEED (integer)``
+    This control turns the camera horizontally at the specific speed.
+    The unit is undefined. A positive value moves the camera to the
+    right (clockwise when viewed from above), a negative value to the
+    left. A value of zero stops the motion if one is in progress and has
+    no effect otherwise.
+
+``V4L2_CID_TILT_SPEED (integer)``
+    This control turns the camera vertically at the specified speed. The
+    unit is undefined. A positive value moves the camera up, a negative
+    value down. A value of zero stops the motion if one is in progress
+    and has no effect otherwise.
+
+.. _v4l2-camera-sensor-orientation:
+
+``V4L2_CID_CAMERA_ORIENTATION (menu)``
+    This read-only control describes the camera orientation by reporting its
+    mounting position on the device where the camera is installed. The control
+    value is constant and not modifiable by software. This control is
+    particularly meaningful for devices which have a well defined orientation,
+    such as phones, laptops and portable devices since the control is expressed
+    as a position relative to the device's intended usage orientation. For
+    example, a camera installed on the user-facing side of a phone, a tablet or
+    a laptop device is said to be have ``V4L2_CAMERA_ORIENTATION_FRONT``
+    orientation, while a camera installed on the opposite side of the front one
+    is said to be have ``V4L2_CAMERA_ORIENTATION_BACK`` orientation. Camera
+    sensors not directly attached to the device, or attached in a way that
+    allows them to move freely, such as webcams and digital cameras, are said to
+    have the ``V4L2_CAMERA_ORIENTATION_EXTERNAL`` orientation.
+
+
+.. tabularcolumns:: |p{7.7cm}|p{9.8cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_CAMERA_ORIENTATION_FRONT``
+      - The camera is oriented towards the user facing side of the device.
+    * - ``V4L2_CAMERA_ORIENTATION_BACK``
+      - The camera is oriented towards the back facing side of the device.
+    * - ``V4L2_CAMERA_ORIENTATION_EXTERNAL``
+      - The camera is not directly attached to the device and is freely movable.
+
+
+.. _v4l2-camera-sensor-rotation:
+
+``V4L2_CID_CAMERA_SENSOR_ROTATION (integer)``
+    This read-only control describes the rotation correction in degrees in the
+    counter-clockwise direction to be applied to the captured images once
+    captured to memory to compensate for the camera sensor mounting rotation.
+
+    For a precise definition of the sensor mounting rotation refer to the
+    extensive description of the 'rotation' properties in the device tree
+    bindings file 'video-interfaces.txt'.
+
+    A few examples are below reported, using a shark swimming from left to
+    right in front of the user as the example scene to capture. ::
+
+                 0               X-axis
+               0 +------------------------------------->
+                 !
+                 !
+                 !
+                 !           |\____)\___
+                 !           ) _____  __`<
+                 !           |/     )/
+                 !
+                 !
+                 !
+                 V
+               Y-axis
+
+    Example one - Webcam
+
+    Assuming you can bring your laptop with you while swimming with sharks,
+    the camera module of the laptop is installed on the user facing part of a
+    laptop screen casing, and is typically used for video calls. The captured
+    images are meant to be displayed in landscape mode (width > height) on the
+    laptop screen.
+
+    The camera is typically mounted upside-down to compensate the lens optical
+    inversion effect. In this case the value of the
+    V4L2_CID_CAMERA_SENSOR_ROTATION control is 0, no rotation is required to
+    display images correctly to the user.
+
+    If the camera sensor is not mounted upside-down it is required to compensate
+    the lens optical inversion effect and the value of the
+    V4L2_CID_CAMERA_SENSOR_ROTATION control is 180 degrees, as images will
+    result rotated when captured to memory. ::
+
+                 +--------------------------------------+
+                 !                                      !
+                 !                                      !
+                 !                                      !
+                 !              __/(_____/|             !
+                 !            >.___  ____ (             !
+                 !                 \(    \|             !
+                 !                                      !
+                 !                                      !
+                 !                                      !
+                 +--------------------------------------+
+
+    A software rotation correction of 180 degrees has to be applied to correctly
+    display the image on the user screen. ::
+
+                 +--------------------------------------+
+                 !                                      !
+                 !                                      !
+                 !                                      !
+                 !             |\____)\___              !
+                 !             ) _____  __`<            !
+                 !             |/     )/                !
+                 !                                      !
+                 !                                      !
+                 !                                      !
+                 +--------------------------------------+
+
+    Example two - Phone camera
+
+    It is more handy to go and swim with sharks with only your mobile phone
+    with you and take pictures with the camera that is installed on the back
+    side of the device, facing away from the user. The captured images are meant
+    to be displayed in portrait mode (height > width) to match the device screen
+    orientation and the device usage orientation used when taking the picture.
+
+    The camera sensor is typically mounted with its pixel array longer side
+    aligned to the device longer side, upside-down mounted to compensate for
+    the lens optical inversion effect.
+
+    The images once captured to memory will be rotated and the value of the
+    V4L2_CID_CAMERA_SENSOR_ROTATION will report a 90 degree rotation. ::
+
+
+                 +-------------------------------------+
+                 |                 _ _                 |
+                 |                \   /                |
+                 |                 | |                 |
+                 |                 | |                 |
+                 |                 |  >                |
+                 |                <  |                 |
+                 |                 | |                 |
+                 |                   .                 |
+                 |                  V                  |
+                 +-------------------------------------+
+
+    A correction of 90 degrees in counter-clockwise direction has to be
+    applied to correctly display the image in portrait mode on the device
+    screen. ::
+
+                          +--------------------+
+                          |                    |
+                          |                    |
+                          |                    |
+                          |                    |
+                          |                    |
+                          |                    |
+                          |   |\____)\___      |
+                          |   ) _____  __`<    |
+                          |   |/     )/        |
+                          |                    |
+                          |                    |
+                          |                    |
+                          |                    |
+                          |                    |
+                          +--------------------+
+
+
+.. [#f1]
+   This control may be changed to a menu control in the future, if more
+   options are required.
+
+``V4L2_CID_HDR_SENSOR_MODE (menu)``
+    Change the sensor HDR mode. A HDR picture is obtained by merging two
+    captures of the same scene using two different exposure periods. HDR mode
+    describes the way these two captures are merged in the sensor.
+
+    As modes differ for each sensor, menu items are not standardized by this
+    control and are left to the programmer.