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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _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.