extended-controls.rst: split up per control class

The extended-controls.rst file had become too big. Split it up: each
control class reference gets its own rst file, and this file just
describes the Extended Control API.

Each control class reference is also moved up one level into the
table of contents to make it easier to find e.g. the codec control
reference.

Finally I rearranged the order so that all camera-related control
classes are grouped together, ditto for codec/jpeg and fm-rx/tx.

The ext-ctrls-codec.rst is still pretty big and it is a candidate
to split up further in the future, possibly per codec.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/uapi/v4l/common.rst

@@ -46,6 +46,17 @@ applicable to all devices.
     dv-timings
     control
     extended-controls
+    ext-ctrls-camera
+    ext-ctrls-flash
+    ext-ctrls-image-source
+    ext-ctrls-image-process
+    ext-ctrls-codec
+    ext-ctrls-jpeg
+    ext-ctrls-dv
+    ext-ctrls-rf-tuner
+    ext-ctrls-fm-tx
+    ext-ctrls-fm-rx
+    ext-ctrls-detect
     format
     planar-apis
     selection-api

Documentation/media/uapi/v4l/ext-ctrls-detect.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _detect-controls:
+
+************************
+Detect Control Reference
+************************
+
+The Detect class includes controls for common features of various motion
+or object detection capable devices.
+
+
+.. _detect-control-id:
+
+Detect Control IDs
+==================
+
+``V4L2_CID_DETECT_CLASS (class)``
+    The Detect class descriptor. Calling
+    :ref:`VIDIOC_QUERYCTRL` for this control will
+    return a description of this control class.
+
+``V4L2_CID_DETECT_MD_MODE (menu)``
+    Sets the motion detection mode.
+
+.. tabularcolumns:: |p{7.5cm}|p{10.0cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_DETECT_MD_MODE_DISABLED``
+      - Disable motion detection.
+    * - ``V4L2_DETECT_MD_MODE_GLOBAL``
+      - Use a single motion detection threshold.
+    * - ``V4L2_DETECT_MD_MODE_THRESHOLD_GRID``
+      - The image is divided into a grid, each cell with its own motion
+	detection threshold. These thresholds are set through the
+	``V4L2_CID_DETECT_MD_THRESHOLD_GRID`` matrix control.
+    * - ``V4L2_DETECT_MD_MODE_REGION_GRID``
+      - The image is divided into a grid, each cell with its own region
+	value that specifies which per-region motion detection thresholds
+	should be used. Each region has its own thresholds. How these
+	per-region thresholds are set up is driver-specific. The region
+	values for the grid are set through the
+	``V4L2_CID_DETECT_MD_REGION_GRID`` matrix control.
+
+
+
+``V4L2_CID_DETECT_MD_GLOBAL_THRESHOLD (integer)``
+    Sets the global motion detection threshold to be used with the
+    ``V4L2_DETECT_MD_MODE_GLOBAL`` motion detection mode.
+
+``V4L2_CID_DETECT_MD_THRESHOLD_GRID (__u16 matrix)``
+    Sets the motion detection thresholds for each cell in the grid. To
+    be used with the ``V4L2_DETECT_MD_MODE_THRESHOLD_GRID`` motion
+    detection mode. Matrix element (0, 0) represents the cell at the
+    top-left of the grid.
+
+``V4L2_CID_DETECT_MD_REGION_GRID (__u8 matrix)``
+    Sets the motion detection region value for each cell in the grid. To
+    be used with the ``V4L2_DETECT_MD_MODE_REGION_GRID`` motion
+    detection mode. Matrix element (0, 0) represents the cell at the
+    top-left of the grid.

Documentation/media/uapi/v4l/ext-ctrls-dv.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _dv-controls:
+
+*******************************
+Digital Video Control Reference
+*******************************
+
+The Digital Video control class is intended to control receivers and
+transmitters for `VGA <http://en.wikipedia.org/wiki/Vga>`__,
+`DVI <http://en.wikipedia.org/wiki/Digital_Visual_Interface>`__
+(Digital Visual Interface), HDMI (:ref:`hdmi`) and DisplayPort
+(:ref:`dp`). These controls are generally expected to be private to
+the receiver or transmitter subdevice that implements them, so they are
+only exposed on the ``/dev/v4l-subdev*`` device node.
+
+.. note::
+
+   Note that these devices can have multiple input or output pads which are
+   hooked up to e.g. HDMI connectors. Even though the subdevice will
+   receive or transmit video from/to only one of those pads, the other pads
+   can still be active when it comes to EDID (Extended Display
+   Identification Data, :ref:`vesaedid`) and HDCP (High-bandwidth Digital
+   Content Protection System, :ref:`hdcp`) processing, allowing the
+   device to do the fairly slow EDID/HDCP handling in advance. This allows
+   for quick switching between connectors.
+
+These pads appear in several of the controls in this section as
+bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad
+1, etc. The maximum value of the control is the set of valid pads.
+
+
+.. _dv-control-id:
+
+Digital Video Control IDs
+=========================
+
+``V4L2_CID_DV_CLASS (class)``
+    The Digital Video class descriptor.
+
+``V4L2_CID_DV_TX_HOTPLUG (bitmask)``
+    Many connectors have a hotplug pin which is high if EDID information
+    is available from the source. This control shows the state of the
+    hotplug pin as seen by the transmitter. Each bit corresponds to an
+    output pad on the transmitter. If an output pad does not have an
+    associated hotplug pin, then the bit for that pad will be 0. This
+    read-only control is applicable to DVI-D, HDMI and DisplayPort
+    connectors.
+
+``V4L2_CID_DV_TX_RXSENSE (bitmask)``
+    Rx Sense is the detection of pull-ups on the TMDS clock lines. This
+    normally means that the sink has left/entered standby (i.e. the
+    transmitter can sense that the receiver is ready to receive video).
+    Each bit corresponds to an output pad on the transmitter. If an
+    output pad does not have an associated Rx Sense, then the bit for
+    that pad will be 0. This read-only control is applicable to DVI-D
+    and HDMI devices.
+
+``V4L2_CID_DV_TX_EDID_PRESENT (bitmask)``
+    When the transmitter sees the hotplug signal from the receiver it
+    will attempt to read the EDID. If set, then the transmitter has read
+    at least the first block (= 128 bytes). Each bit corresponds to an
+    output pad on the transmitter. If an output pad does not support
+    EDIDs, then the bit for that pad will be 0. This read-only control
+    is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
+
+``V4L2_CID_DV_TX_MODE``
+    (enum)
+
+enum v4l2_dv_tx_mode -
+    HDMI transmitters can transmit in DVI-D mode (just video) or in HDMI
+    mode (video + audio + auxiliary data). This control selects which
+    mode to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
+    This control is applicable to HDMI connectors.
+
+``V4L2_CID_DV_TX_RGB_RANGE``
+    (enum)
+
+enum v4l2_dv_rgb_range -
+    Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
+    follows the RGB quantization range specified in the standard for the
+    video interface (ie. :ref:`cea861` for HDMI).
+    V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the
+    standard to be compatible with sinks that have not implemented the
+    standard correctly (unfortunately quite common for HDMI and DVI-D).
+    Full range allows all possible values to be used whereas limited
+    range sets the range to (16 << (N-8)) - (235 << (N-8)) where N is
+    the number of bits per component. This control is applicable to VGA,
+    DVI-A/D, HDMI and DisplayPort connectors.
+
+``V4L2_CID_DV_TX_IT_CONTENT_TYPE``
+    (enum)
+
+enum v4l2_dv_it_content_type -
+    Configures the IT Content Type of the transmitted video. This
+    information is sent over HDMI and DisplayPort connectors as part of
+    the AVI InfoFrame. The term 'IT Content' is used for content that
+    originates from a computer as opposed to content from a TV broadcast
+    or an analog source. The enum v4l2_dv_it_content_type defines
+    the possible content types:
+
+.. tabularcolumns:: |p{7.0cm}|p{10.5cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_DV_IT_CONTENT_TYPE_GRAPHICS``
+      - Graphics content. Pixel data should be passed unfiltered and
+	without analog reconstruction.
+    * - ``V4L2_DV_IT_CONTENT_TYPE_PHOTO``
+      - Photo content. The content is derived from digital still pictures.
+	The content should be passed through with minimal scaling and
+	picture enhancements.
+    * - ``V4L2_DV_IT_CONTENT_TYPE_CINEMA``
+      - Cinema content.
+    * - ``V4L2_DV_IT_CONTENT_TYPE_GAME``
+      - Game content. Audio and video latency should be minimized.
+    * - ``V4L2_DV_IT_CONTENT_TYPE_NO_ITC``
+      - No IT Content information is available and the ITC bit in the AVI
+	InfoFrame is set to 0.
+
+
+
+``V4L2_CID_DV_RX_POWER_PRESENT (bitmask)``
+    Detects whether the receiver receives power from the source (e.g.
+    HDMI carries 5V on one of the pins). This is often used to power an
+    eeprom which contains EDID information, such that the source can
+    read the EDID even if the sink is in standby/power off. Each bit
+    corresponds to an input pad on the receiver. If an input pad
+    cannot detect whether power is present, then the bit for that pad
+    will be 0. This read-only control is applicable to DVI-D, HDMI and
+    DisplayPort connectors.
+
+``V4L2_CID_DV_RX_RGB_RANGE``
+    (enum)
+
+enum v4l2_dv_rgb_range -
+    Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
+    follows the RGB quantization range specified in the standard for the
+    video interface (ie. :ref:`cea861` for HDMI).
+    V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the
+    standard to be compatible with sources that have not implemented the
+    standard correctly (unfortunately quite common for HDMI and DVI-D).
+    Full range allows all possible values to be used whereas limited
+    range sets the range to (16 << (N-8)) - (235 << (N-8)) where N is
+    the number of bits per component. This control is applicable to VGA,
+    DVI-A/D, HDMI and DisplayPort connectors.
+
+``V4L2_CID_DV_RX_IT_CONTENT_TYPE``
+    (enum)
+
+enum v4l2_dv_it_content_type -
+    Reads the IT Content Type of the received video. This information is
+    sent over HDMI and DisplayPort connectors as part of the AVI
+    InfoFrame. The term 'IT Content' is used for content that originates
+    from a computer as opposed to content from a TV broadcast or an
+    analog source. See ``V4L2_CID_DV_TX_IT_CONTENT_TYPE`` for the
+    available content types.

Documentation/media/uapi/v4l/ext-ctrls-flash.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _flash-controls:
+
+***********************
+Flash Control Reference
+***********************
+
+The V4L2 flash controls are intended to provide generic access to flash
+controller devices. Flash controller devices are typically used in
+digital cameras.
+
+The interface can support both LED and xenon flash devices. As of
+writing this, there is no xenon flash driver using this interface.
+
+
+.. _flash-controls-use-cases:
+
+Supported use cases
+===================
+
+
+Unsynchronised LED flash (software strobe)
+------------------------------------------
+
+Unsynchronised LED flash is controlled directly by the host as the
+sensor. The flash must be enabled by the host before the exposure of the
+image starts and disabled once it ends. The host is fully responsible
+for the timing of the flash.
+
+Example of such device: Nokia N900.
+
+
+Synchronised LED flash (hardware strobe)
+----------------------------------------
+
+The synchronised LED flash is pre-programmed by the host (power and
+timeout) but controlled by the sensor through a strobe signal from the
+sensor to the flash.
+
+The sensor controls the flash duration and timing. This information
+typically must be made available to the sensor.
+
+
+LED flash as torch
+------------------
+
+LED flash may be used as torch in conjunction with another use case
+involving camera or individually.
+
+
+.. _flash-control-id:
+
+Flash Control IDs
+-----------------
+
+``V4L2_CID_FLASH_CLASS (class)``
+    The FLASH class descriptor.
+
+``V4L2_CID_FLASH_LED_MODE (menu)``
+    Defines the mode of the flash LED, the high-power white LED attached
+    to the flash controller. Setting this control may not be possible in
+    presence of some faults. See V4L2_CID_FLASH_FAULT.
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_FLASH_LED_MODE_NONE``
+      - Off.
+    * - ``V4L2_FLASH_LED_MODE_FLASH``
+      - Flash mode.
+    * - ``V4L2_FLASH_LED_MODE_TORCH``
+      - Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.
+
+
+
+``V4L2_CID_FLASH_STROBE_SOURCE (menu)``
+    Defines the source of the flash LED strobe.
+
+.. tabularcolumns:: |p{7.0cm}|p{10.5cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_FLASH_STROBE_SOURCE_SOFTWARE``
+      - The flash strobe is triggered by using the
+	V4L2_CID_FLASH_STROBE control.
+    * - ``V4L2_FLASH_STROBE_SOURCE_EXTERNAL``
+      - The flash strobe is triggered by an external source. Typically
+	this is a sensor, which makes it possible to synchronises the
+	flash strobe start to exposure start.
+
+
+
+``V4L2_CID_FLASH_STROBE (button)``
+    Strobe flash. Valid when V4L2_CID_FLASH_LED_MODE is set to
+    V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
+    is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
+    control may not be possible in presence of some faults. See
+    V4L2_CID_FLASH_FAULT.
+
+``V4L2_CID_FLASH_STROBE_STOP (button)``
+    Stop flash strobe immediately.
+
+``V4L2_CID_FLASH_STROBE_STATUS (boolean)``
+    Strobe status: whether the flash is strobing at the moment or not.
+    This is a read-only control.
+
+``V4L2_CID_FLASH_TIMEOUT (integer)``
+    Hardware timeout for flash. The flash strobe is stopped after this
+    period of time has passed from the start of the strobe.
+
+``V4L2_CID_FLASH_INTENSITY (integer)``
+    Intensity of the flash strobe when the flash LED is in flash mode
+    (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps (mA)
+    if possible.
+
+``V4L2_CID_FLASH_TORCH_INTENSITY (integer)``
+    Intensity of the flash LED in torch mode
+    (V4L2_FLASH_LED_MODE_TORCH). The unit should be milliamps (mA)
+    if possible. Setting this control may not be possible in presence of
+    some faults. See V4L2_CID_FLASH_FAULT.
+
+``V4L2_CID_FLASH_INDICATOR_INTENSITY (integer)``
+    Intensity of the indicator LED. The indicator LED may be fully
+    independent of the flash LED. The unit should be microamps (uA) if
+    possible.
+
+``V4L2_CID_FLASH_FAULT (bitmask)``
+    Faults related to the flash. The faults tell about specific problems
+    in the flash chip itself or the LEDs attached to it. Faults may
+    prevent further use of some of the flash controls. In particular,
+    V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
+    if the fault affects the flash LED. Exactly which faults have such
+    an effect is chip dependent. Reading the faults resets the control
+    and returns the chip to a usable state if possible.
+
+.. tabularcolumns:: |p{8.0cm}|p{9.5cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_FLASH_FAULT_OVER_VOLTAGE``
+      - Flash controller voltage to the flash LED has exceeded the limit
+	specific to the flash controller.
+    * - ``V4L2_FLASH_FAULT_TIMEOUT``
+      - The flash strobe was still on when the timeout set by the user ---
+	V4L2_CID_FLASH_TIMEOUT control --- has expired. Not all flash
+	controllers may set this in all such conditions.
+    * - ``V4L2_FLASH_FAULT_OVER_TEMPERATURE``
+      - The flash controller has overheated.
+    * - ``V4L2_FLASH_FAULT_SHORT_CIRCUIT``
+      - The short circuit protection of the flash controller has been
+	triggered.
+    * - ``V4L2_FLASH_FAULT_OVER_CURRENT``
+      - Current in the LED power supply has exceeded the limit specific to
+	the flash controller.
+    * - ``V4L2_FLASH_FAULT_INDICATOR``
+      - The flash controller has detected a short or open circuit
+	condition on the indicator LED.
+    * - ``V4L2_FLASH_FAULT_UNDER_VOLTAGE``
+      - Flash controller voltage to the flash LED has been below the
+	minimum limit specific to the flash controller.
+    * - ``V4L2_FLASH_FAULT_INPUT_VOLTAGE``
+      - The input voltage of the flash controller is below the limit under
+	which strobing the flash at full current will not be possible.The
+	condition persists until this flag is no longer set.
+    * - ``V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE``
+      - The temperature of the LED has exceeded its allowed upper limit.
+
+
+
+``V4L2_CID_FLASH_CHARGE (boolean)``
+    Enable or disable charging of the xenon flash capacitor.
+
+``V4L2_CID_FLASH_READY (boolean)``
+    Is the flash ready to strobe? Xenon flashes require their capacitors
+    charged before strobing. LED flashes often require a cooldown period
+    after strobe during which another strobe will not be possible. This
+    is a read-only control.

Documentation/media/uapi/v4l/ext-ctrls-fm-rx.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _fm-rx-controls:
+
+*****************************
+FM Receiver Control Reference
+*****************************
+
+The FM Receiver (FM_RX) class includes controls for common features of
+FM Reception capable devices.
+
+
+.. _fm-rx-control-id:
+
+FM_RX Control IDs
+=================
+
+``V4L2_CID_FM_RX_CLASS (class)``
+    The FM_RX class descriptor. Calling
+    :ref:`VIDIOC_QUERYCTRL` for this control will
+    return a description of this control class.
+
+``V4L2_CID_RDS_RECEPTION (boolean)``
+    Enables/disables RDS reception by the radio tuner
+
+``V4L2_CID_RDS_RX_PTY (integer)``
+    Gets RDS Programme Type field. This encodes up to 31 pre-defined
+    programme types.
+
+``V4L2_CID_RDS_RX_PS_NAME (string)``
+    Gets the Programme Service name (PS_NAME). It is intended for
+    static display on a receiver. It is the primary aid to listeners in
+    programme service identification and selection. In Annex E of
+    :ref:`iec62106`, the RDS specification, there is a full
+    description of the correct character encoding for Programme Service
+    name strings. Also from RDS specification, PS is usually a single
+    eight character text. However, it is also possible to find receivers
+    which can scroll strings sized as 8 x N characters. So, this control
+    must be configured with steps of 8 characters. The result is it must
+    always contain a string with size multiple of 8.
+
+``V4L2_CID_RDS_RX_RADIO_TEXT (string)``
+    Gets the Radio Text info. It is a textual description of what is
+    being broadcasted. RDS Radio Text can be applied when broadcaster
+    wishes to transmit longer PS names, programme-related information or
+    any other text. In these cases, RadioText can be used in addition to
+    ``V4L2_CID_RDS_RX_PS_NAME``. The encoding for Radio Text strings is
+    also fully described in Annex E of :ref:`iec62106`. The length of
+    Radio Text strings depends on which RDS Block is being used to
+    transmit it, either 32 (2A block) or 64 (2B block). However, it is
+    also possible to find receivers which can scroll strings sized as 32
+    x N or 64 x N characters. So, this control must be configured with
+    steps of 32 or 64 characters. The result is it must always contain a
+    string with size multiple of 32 or 64.
+
+``V4L2_CID_RDS_RX_TRAFFIC_ANNOUNCEMENT (boolean)``
+    If set, then a traffic announcement is in progress.
+
+``V4L2_CID_RDS_RX_TRAFFIC_PROGRAM (boolean)``
+    If set, then the tuned programme carries traffic announcements.
+
+``V4L2_CID_RDS_RX_MUSIC_SPEECH (boolean)``
+    If set, then this channel broadcasts music. If cleared, then it
+    broadcasts speech. If the transmitter doesn't make this distinction,
+    then it will be set.
+
+``V4L2_CID_TUNE_DEEMPHASIS``
+    (enum)
+
+enum v4l2_deemphasis -
+    Configures the de-emphasis value for reception. A de-emphasis filter
+    is applied to the broadcast to accentuate the high audio
+    frequencies. Depending on the region, a time constant of either 50
+    or 75 useconds is used. The enum v4l2_deemphasis defines possible
+    values for de-emphasis. Here they are:
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_DEEMPHASIS_DISABLED``
+      - No de-emphasis is applied.
+    * - ``V4L2_DEEMPHASIS_50_uS``
+      - A de-emphasis of 50 uS is used.
+    * - ``V4L2_DEEMPHASIS_75_uS``
+      - A de-emphasis of 75 uS is used.

Documentation/media/uapi/v4l/ext-ctrls-fm-tx.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _fm-tx-controls:
+
+********************************
+FM Transmitter Control Reference
+********************************
+
+The FM Transmitter (FM_TX) class includes controls for common features
+of FM transmissions capable devices. Currently this class includes
+parameters for audio compression, pilot tone generation, audio deviation
+limiter, RDS transmission and tuning power features.
+
+
+.. _fm-tx-control-id:
+
+FM_TX Control IDs
+=================
+
+``V4L2_CID_FM_TX_CLASS (class)``
+    The FM_TX class descriptor. Calling
+    :ref:`VIDIOC_QUERYCTRL` for this control will
+    return a description of this control class.
+
+``V4L2_CID_RDS_TX_DEVIATION (integer)``
+    Configures RDS signal frequency deviation level in Hz. The range and
+    step are driver-specific.
+
+``V4L2_CID_RDS_TX_PI (integer)``
+    Sets the RDS Programme Identification field for transmission.
+
+``V4L2_CID_RDS_TX_PTY (integer)``
+    Sets the RDS Programme Type field for transmission. This encodes up
+    to 31 pre-defined programme types.
+
+``V4L2_CID_RDS_TX_PS_NAME (string)``
+    Sets the Programme Service name (PS_NAME) for transmission. It is
+    intended for static display on a receiver. It is the primary aid to
+    listeners in programme service identification and selection. In
+    Annex E of :ref:`iec62106`, the RDS specification, there is a full
+    description of the correct character encoding for Programme Service
+    name strings. Also from RDS specification, PS is usually a single
+    eight character text. However, it is also possible to find receivers
+    which can scroll strings sized as 8 x N characters. So, this control
+    must be configured with steps of 8 characters. The result is it must
+    always contain a string with size multiple of 8.
+
+``V4L2_CID_RDS_TX_RADIO_TEXT (string)``
+    Sets the Radio Text info for transmission. It is a textual
+    description of what is being broadcasted. RDS Radio Text can be
+    applied when broadcaster wishes to transmit longer PS names,
+    programme-related information or any other text. In these cases,
+    RadioText should be used in addition to ``V4L2_CID_RDS_TX_PS_NAME``.
+    The encoding for Radio Text strings is also fully described in Annex
+    E of :ref:`iec62106`. The length of Radio Text strings depends on
+    which RDS Block is being used to transmit it, either 32 (2A block)
+    or 64 (2B block). However, it is also possible to find receivers
+    which can scroll strings sized as 32 x N or 64 x N characters. So,
+    this control must be configured with steps of 32 or 64 characters.
+    The result is it must always contain a string with size multiple of
+    32 or 64.
+
+``V4L2_CID_RDS_TX_MONO_STEREO (boolean)``
+    Sets the Mono/Stereo bit of the Decoder Identification code. If set,
+    then the audio was recorded as stereo.
+
+``V4L2_CID_RDS_TX_ARTIFICIAL_HEAD (boolean)``
+    Sets the
+    `Artificial Head <http://en.wikipedia.org/wiki/Artificial_head>`__
+    bit of the Decoder Identification code. If set, then the audio was
+    recorded using an artificial head.
+
+``V4L2_CID_RDS_TX_COMPRESSED (boolean)``
+    Sets the Compressed bit of the Decoder Identification code. If set,
+    then the audio is compressed.
+
+``V4L2_CID_RDS_TX_DYNAMIC_PTY (boolean)``
+    Sets the Dynamic PTY bit of the Decoder Identification code. If set,
+    then the PTY code is dynamically switched.
+
+``V4L2_CID_RDS_TX_TRAFFIC_ANNOUNCEMENT (boolean)``
+    If set, then a traffic announcement is in progress.
+
+``V4L2_CID_RDS_TX_TRAFFIC_PROGRAM (boolean)``
+    If set, then the tuned programme carries traffic announcements.
+
+``V4L2_CID_RDS_TX_MUSIC_SPEECH (boolean)``
+    If set, then this channel broadcasts music. If cleared, then it
+    broadcasts speech. If the transmitter doesn't make this distinction,
+    then it should be set.
+
+``V4L2_CID_RDS_TX_ALT_FREQS_ENABLE (boolean)``
+    If set, then transmit alternate frequencies.
+
+``V4L2_CID_RDS_TX_ALT_FREQS (__u32 array)``
+    The alternate frequencies in kHz units. The RDS standard allows for
+    up to 25 frequencies to be defined. Drivers may support fewer
+    frequencies so check the array size.
+
+``V4L2_CID_AUDIO_LIMITER_ENABLED (boolean)``
+    Enables or disables the audio deviation limiter feature. The limiter
+    is useful when trying to maximize the audio volume, minimize
+    receiver-generated distortion and prevent overmodulation.
+
+``V4L2_CID_AUDIO_LIMITER_RELEASE_TIME (integer)``
+    Sets the audio deviation limiter feature release time. Unit is in
+    useconds. Step and range are driver-specific.
+
+``V4L2_CID_AUDIO_LIMITER_DEVIATION (integer)``
+    Configures audio frequency deviation level in Hz. The range and step
+    are driver-specific.
+
+``V4L2_CID_AUDIO_COMPRESSION_ENABLED (boolean)``
+    Enables or disables the audio compression feature. This feature
+    amplifies signals below the threshold by a fixed gain and compresses
+    audio signals above the threshold by the ratio of Threshold/(Gain +
+    Threshold).
+
+``V4L2_CID_AUDIO_COMPRESSION_GAIN (integer)``
+    Sets the gain for audio compression feature. It is a dB value. The
+    range and step are driver-specific.
+
+``V4L2_CID_AUDIO_COMPRESSION_THRESHOLD (integer)``
+    Sets the threshold level for audio compression freature. It is a dB
+    value. The range and step are driver-specific.
+
+``V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME (integer)``
+    Sets the attack time for audio compression feature. It is a useconds
+    value. The range and step are driver-specific.
+
+``V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME (integer)``
+    Sets the release time for audio compression feature. It is a
+    useconds value. The range and step are driver-specific.
+
+``V4L2_CID_PILOT_TONE_ENABLED (boolean)``
+    Enables or disables the pilot tone generation feature.
+
+``V4L2_CID_PILOT_TONE_DEVIATION (integer)``
+    Configures pilot tone frequency deviation level. Unit is in Hz. The
+    range and step are driver-specific.
+
+``V4L2_CID_PILOT_TONE_FREQUENCY (integer)``
+    Configures pilot tone frequency value. Unit is in Hz. The range and
+    step are driver-specific.
+
+``V4L2_CID_TUNE_PREEMPHASIS``
+    (enum)
+
+enum v4l2_preemphasis -
+    Configures the pre-emphasis value for broadcasting. A pre-emphasis
+    filter is applied to the broadcast to accentuate the high audio
+    frequencies. Depending on the region, a time constant of either 50
+    or 75 useconds is used. The enum v4l2_preemphasis defines possible
+    values for pre-emphasis. Here they are:
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_PREEMPHASIS_DISABLED``
+      - No pre-emphasis is applied.
+    * - ``V4L2_PREEMPHASIS_50_uS``
+      - A pre-emphasis of 50 uS is used.
+    * - ``V4L2_PREEMPHASIS_75_uS``
+      - A pre-emphasis of 75 uS is used.
+
+
+
+``V4L2_CID_TUNE_POWER_LEVEL (integer)``
+    Sets the output power level for signal transmission. Unit is in
+    dBuV. Range and step are driver-specific.
+
+``V4L2_CID_TUNE_ANTENNA_CAPACITOR (integer)``
+    This selects the value of antenna tuning capacitor manually or
+    automatically if set to zero. Unit, range and step are
+    driver-specific.
+
+For more details about RDS specification, refer to :ref:`iec62106`
+document, from CENELEC.

Documentation/media/uapi/v4l/ext-ctrls-image-process.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _image-process-controls:
+
+*******************************
+Image Process Control Reference
+*******************************
+
+The Image Process control class is intended for low-level control of
+image processing functions. Unlike ``V4L2_CID_IMAGE_SOURCE_CLASS``, the
+controls in this class affect processing the image, and do not control
+capturing of it.
+
+
+.. _image-process-control-id:
+
+Image Process Control IDs
+=========================
+
+``V4L2_CID_IMAGE_PROC_CLASS (class)``
+    The IMAGE_PROC class descriptor.
+
+``V4L2_CID_LINK_FREQ (integer menu)``
+    Data bus frequency. Together with the media bus pixel code, bus type
+    (clock cycles per sample), the data bus frequency defines the pixel
+    rate (``V4L2_CID_PIXEL_RATE``) in the pixel array (or possibly
+    elsewhere, if the device is not an image sensor). The frame rate can
+    be calculated from the pixel clock, image width and height and
+    horizontal and vertical blanking. While the pixel rate control may
+    be defined elsewhere than in the subdev containing the pixel array,
+    the frame rate cannot be obtained from that information. This is
+    because only on the pixel array it can be assumed that the vertical
+    and horizontal blanking information is exact: no other blanking is
+    allowed in the pixel array. The selection of frame rate is performed
+    by selecting the desired horizontal and vertical blanking. The unit
+    of this control is Hz.
+
+``V4L2_CID_PIXEL_RATE (64-bit integer)``
+    Pixel rate in the source pads of the subdev. This control is
+    read-only and its unit is pixels / second.
+
+``V4L2_CID_TEST_PATTERN (menu)``
+    Some capture/display/sensor devices have the capability to generate
+    test pattern images. These hardware specific test patterns can be
+    used to test if a device is working properly.
+
+``V4L2_CID_DEINTERLACING_MODE (menu)``
+    The video deinterlacing mode (such as Bob, Weave, ...). The menu items are
+    driver specific and are documented in :ref:`v4l-drivers`.
+
+``V4L2_CID_DIGITAL_GAIN (integer)``
+    Digital gain is the value by which all colour components
+    are multiplied by. Typically the digital gain applied is the
+    control value divided by e.g. 0x100, meaning that to get no
+    digital gain the control value needs to be 0x100. The no-gain
+    configuration is also typically the default.

Documentation/media/uapi/v4l/ext-ctrls-image-source.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _image-source-controls:
+
+******************************
+Image Source Control Reference
+******************************
+
+The Image Source control class is intended for low-level control of
+image source devices such as image sensors. The devices feature an
+analogue to digital converter and a bus transmitter to transmit the
+image data out of the device.
+
+
+.. _image-source-control-id:
+
+Image Source Control IDs
+========================
+
+``V4L2_CID_IMAGE_SOURCE_CLASS (class)``
+    The IMAGE_SOURCE class descriptor.
+
+``V4L2_CID_VBLANK (integer)``
+    Vertical blanking. The idle period after every frame during which no
+    image data is produced. The unit of vertical blanking is a line.
+    Every line has length of the image width plus horizontal blanking at
+    the pixel rate defined by ``V4L2_CID_PIXEL_RATE`` control in the
+    same sub-device.
+
+``V4L2_CID_HBLANK (integer)``
+    Horizontal blanking. The idle period after every line of image data
+    during which no image data is produced. The unit of horizontal
+    blanking is pixels.
+
+``V4L2_CID_ANALOGUE_GAIN (integer)``
+    Analogue gain is gain affecting all colour components in the pixel
+    matrix. The gain operation is performed in the analogue domain
+    before A/D conversion.
+
+``V4L2_CID_TEST_PATTERN_RED (integer)``
+    Test pattern red colour component.
+
+``V4L2_CID_TEST_PATTERN_GREENR (integer)``
+    Test pattern green (next to red) colour component.
+
+``V4L2_CID_TEST_PATTERN_BLUE (integer)``
+    Test pattern blue colour component.
+
+``V4L2_CID_TEST_PATTERN_GREENB (integer)``
+    Test pattern green (next to blue) colour component.

Documentation/media/uapi/v4l/ext-ctrls-jpeg.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _jpeg-controls:
+
+**********************
+JPEG Control Reference
+**********************
+
+The JPEG class includes controls for common features of JPEG encoders
+and decoders. Currently it includes features for codecs implementing
+progressive baseline DCT compression process with Huffman entrophy
+coding.
+
+
+.. _jpeg-control-id:
+
+JPEG Control IDs
+================
+
+``V4L2_CID_JPEG_CLASS (class)``
+    The JPEG class descriptor. Calling
+    :ref:`VIDIOC_QUERYCTRL` for this control will
+    return a description of this control class.
+
+``V4L2_CID_JPEG_CHROMA_SUBSAMPLING (menu)``
+    The chroma subsampling factors describe how each component of an
+    input image is sampled, in respect to maximum sample rate in each
+    spatial dimension. See :ref:`itu-t81`, clause A.1.1. for more
+    details. The ``V4L2_CID_JPEG_CHROMA_SUBSAMPLING`` control determines
+    how Cb and Cr components are downsampled after converting an input
+    image from RGB to Y'CbCr color space.
+
+.. tabularcolumns:: |p{7.0cm}|p{10.5cm}|
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_JPEG_CHROMA_SUBSAMPLING_444``
+      - No chroma subsampling, each pixel has Y, Cr and Cb values.
+    * - ``V4L2_JPEG_CHROMA_SUBSAMPLING_422``
+      - Horizontally subsample Cr, Cb components by a factor of 2.
+    * - ``V4L2_JPEG_CHROMA_SUBSAMPLING_420``
+      - Subsample Cr, Cb components horizontally and vertically by 2.
+    * - ``V4L2_JPEG_CHROMA_SUBSAMPLING_411``
+      - Horizontally subsample Cr, Cb components by a factor of 4.
+    * - ``V4L2_JPEG_CHROMA_SUBSAMPLING_410``
+      - Subsample Cr, Cb components horizontally by 4 and vertically by 2.
+    * - ``V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY``
+      - Use only luminance component.
+
+
+
+``V4L2_CID_JPEG_RESTART_INTERVAL (integer)``
+    The restart interval determines an interval of inserting RSTm
+    markers (m = 0..7). The purpose of these markers is to additionally
+    reinitialize the encoder process, in order to process blocks of an
+    image independently. For the lossy compression processes the restart
+    interval unit is MCU (Minimum Coded Unit) and its value is contained
+    in DRI (Define Restart Interval) marker. If
+    ``V4L2_CID_JPEG_RESTART_INTERVAL`` control is set to 0, DRI and RSTm
+    markers will not be inserted.
+
+.. _jpeg-quality-control:
+
+``V4L2_CID_JPEG_COMPRESSION_QUALITY (integer)``
+    ``V4L2_CID_JPEG_COMPRESSION_QUALITY`` control determines trade-off
+    between image quality and size. It provides simpler method for
+    applications to control image quality, without a need for direct
+    reconfiguration of luminance and chrominance quantization tables. In
+    cases where a driver uses quantization tables configured directly by
+    an application, using interfaces defined elsewhere,
+    ``V4L2_CID_JPEG_COMPRESSION_QUALITY`` control should be set by
+    driver to 0.
+
+    The value range of this control is driver-specific. Only positive,
+    non-zero values are meaningful. The recommended range is 1 - 100,
+    where larger values correspond to better image quality.
+
+.. _jpeg-active-marker-control:
+
+``V4L2_CID_JPEG_ACTIVE_MARKER (bitmask)``
+    Specify which JPEG markers are included in compressed stream. This
+    control is valid only for encoders.
+
+
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_JPEG_ACTIVE_MARKER_APP0``
+      - Application data segment APP\ :sub:`0`.
+    * - ``V4L2_JPEG_ACTIVE_MARKER_APP1``
+      - Application data segment APP\ :sub:`1`.
+    * - ``V4L2_JPEG_ACTIVE_MARKER_COM``
+      - Comment segment.
+    * - ``V4L2_JPEG_ACTIVE_MARKER_DQT``
+      - Quantization tables segment.
+    * - ``V4L2_JPEG_ACTIVE_MARKER_DHT``
+      - Huffman tables segment.
+
+
+
+For more details about JPEG specification, refer to :ref:`itu-t81`,
+:ref:`jfif`, :ref:`w3c-jpeg-jfif`.

Documentation/media/uapi/v4l/ext-ctrls-rf-tuner.rst

+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/media/uapi/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _rf-tuner-controls:
+
+**************************
+RF Tuner Control Reference
+**************************
+
+The RF Tuner (RF_TUNER) class includes controls for common features of
+devices having RF tuner.
+
+In this context, RF tuner is radio receiver circuit between antenna and
+demodulator. It receives radio frequency (RF) from the antenna and
+converts that received signal to lower intermediate frequency (IF) or
+baseband frequency (BB). Tuners that could do baseband output are often
+called Zero-IF tuners. Older tuners were typically simple PLL tuners
+inside a metal box, while newer ones are highly integrated chips
+without a metal box "silicon tuners". These controls are mostly
+applicable for new feature rich silicon tuners, just because older
+tuners does not have much adjustable features.
+
+For more information about RF tuners see
+`Tuner (radio) <http://en.wikipedia.org/wiki/Tuner_%28radio%29>`__
+and `RF front end <http://en.wikipedia.org/wiki/RF_front_end>`__
+from Wikipedia.
+
+
+.. _rf-tuner-control-id:
+
+RF_TUNER Control IDs
+====================
+
+``V4L2_CID_RF_TUNER_CLASS (class)``
+    The RF_TUNER class descriptor. Calling
+    :ref:`VIDIOC_QUERYCTRL` for this control will
+    return a description of this control class.
+
+``V4L2_CID_RF_TUNER_BANDWIDTH_AUTO (boolean)``
+    Enables/disables tuner radio channel bandwidth configuration. In
+    automatic mode bandwidth configuration is performed by the driver.
+
+``V4L2_CID_RF_TUNER_BANDWIDTH (integer)``
+    Filter(s) on tuner signal path are used to filter signal according
+    to receiving party needs. Driver configures filters to fulfill
+    desired bandwidth requirement. Used when
+    V4L2_CID_RF_TUNER_BANDWIDTH_AUTO is not set. Unit is in Hz. The
+    range and step are driver-specific.
+
+``V4L2_CID_RF_TUNER_LNA_GAIN_AUTO (boolean)``
+    Enables/disables LNA automatic gain control (AGC)
+
+``V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO (boolean)``
+    Enables/disables mixer automatic gain control (AGC)
+
+``V4L2_CID_RF_TUNER_IF_GAIN_AUTO (boolean)``
+    Enables/disables IF automatic gain control (AGC)
+
+``V4L2_CID_RF_TUNER_RF_GAIN (integer)``
+    The RF amplifier is the very first amplifier on the receiver signal
+    path, just right after the antenna input. The difference between the
+    LNA gain and the RF gain in this document is that the LNA gain is
+    integrated in the tuner chip while the RF gain is a separate chip.
+    There may be both RF and LNA gain controls in the same device. The
+    range and step are driver-specific.
+
+``V4L2_CID_RF_TUNER_LNA_GAIN (integer)``
+    LNA (low noise amplifier) gain is first gain stage on the RF tuner
+    signal path. It is located very close to tuner antenna input. Used
+    when ``V4L2_CID_RF_TUNER_LNA_GAIN_AUTO`` is not set. See
+    ``V4L2_CID_RF_TUNER_RF_GAIN`` to understand how RF gain and LNA gain
+    differs from the each others. The range and step are
+    driver-specific.
+
+``V4L2_CID_RF_TUNER_MIXER_GAIN (integer)``
+    Mixer gain is second gain stage on the RF tuner signal path. It is
+    located inside mixer block, where RF signal is down-converted by the
+    mixer. Used when ``V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO`` is not set.
+    The range and step are driver-specific.
+
+``V4L2_CID_RF_TUNER_IF_GAIN (integer)``
+    IF gain is last gain stage on the RF tuner signal path. It is
+    located on output of RF tuner. It controls signal level of
+    intermediate frequency output or baseband output. Used when
+    ``V4L2_CID_RF_TUNER_IF_GAIN_AUTO`` is not set. The range and step
+    are driver-specific.
+
+``V4L2_CID_RF_TUNER_PLL_LOCK (boolean)``
+    Is synthesizer PLL locked? RF tuner is receiving given frequency
+    when that control is set. This is a read-only control.