cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ext-ctrls-rf-tuner.rst (3758B)


      1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
      2
      3.. _rf-tuner-controls:
      4
      5**************************
      6RF Tuner Control Reference
      7**************************
      8
      9The RF Tuner (RF_TUNER) class includes controls for common features of
     10devices having RF tuner.
     11
     12In this context, RF tuner is radio receiver circuit between antenna and
     13demodulator. It receives radio frequency (RF) from the antenna and
     14converts that received signal to lower intermediate frequency (IF) or
     15baseband frequency (BB). Tuners that could do baseband output are often
     16called Zero-IF tuners. Older tuners were typically simple PLL tuners
     17inside a metal box, while newer ones are highly integrated chips
     18without a metal box "silicon tuners". These controls are mostly
     19applicable for new feature rich silicon tuners, just because older
     20tuners does not have much adjustable features.
     21
     22For more information about RF tuners see
     23`Tuner (radio) <http://en.wikipedia.org/wiki/Tuner_%28radio%29>`__
     24and `RF front end <http://en.wikipedia.org/wiki/RF_front_end>`__
     25from Wikipedia.
     26
     27
     28.. _rf-tuner-control-id:
     29
     30RF_TUNER Control IDs
     31====================
     32
     33``V4L2_CID_RF_TUNER_CLASS (class)``
     34    The RF_TUNER class descriptor. Calling
     35    :ref:`VIDIOC_QUERYCTRL` for this control will
     36    return a description of this control class.
     37
     38``V4L2_CID_RF_TUNER_BANDWIDTH_AUTO (boolean)``
     39    Enables/disables tuner radio channel bandwidth configuration. In
     40    automatic mode bandwidth configuration is performed by the driver.
     41
     42``V4L2_CID_RF_TUNER_BANDWIDTH (integer)``
     43    Filter(s) on tuner signal path are used to filter signal according
     44    to receiving party needs. Driver configures filters to fulfill
     45    desired bandwidth requirement. Used when
     46    V4L2_CID_RF_TUNER_BANDWIDTH_AUTO is not set. Unit is in Hz. The
     47    range and step are driver-specific.
     48
     49``V4L2_CID_RF_TUNER_LNA_GAIN_AUTO (boolean)``
     50    Enables/disables LNA automatic gain control (AGC)
     51
     52``V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO (boolean)``
     53    Enables/disables mixer automatic gain control (AGC)
     54
     55``V4L2_CID_RF_TUNER_IF_GAIN_AUTO (boolean)``
     56    Enables/disables IF automatic gain control (AGC)
     57
     58``V4L2_CID_RF_TUNER_RF_GAIN (integer)``
     59    The RF amplifier is the very first amplifier on the receiver signal
     60    path, just right after the antenna input. The difference between the
     61    LNA gain and the RF gain in this document is that the LNA gain is
     62    integrated in the tuner chip while the RF gain is a separate chip.
     63    There may be both RF and LNA gain controls in the same device. The
     64    range and step are driver-specific.
     65
     66``V4L2_CID_RF_TUNER_LNA_GAIN (integer)``
     67    LNA (low noise amplifier) gain is first gain stage on the RF tuner
     68    signal path. It is located very close to tuner antenna input. Used
     69    when ``V4L2_CID_RF_TUNER_LNA_GAIN_AUTO`` is not set. See
     70    ``V4L2_CID_RF_TUNER_RF_GAIN`` to understand how RF gain and LNA gain
     71    differs from the each others. The range and step are
     72    driver-specific.
     73
     74``V4L2_CID_RF_TUNER_MIXER_GAIN (integer)``
     75    Mixer gain is second gain stage on the RF tuner signal path. It is
     76    located inside mixer block, where RF signal is down-converted by the
     77    mixer. Used when ``V4L2_CID_RF_TUNER_MIXER_GAIN_AUTO`` is not set.
     78    The range and step are driver-specific.
     79
     80``V4L2_CID_RF_TUNER_IF_GAIN (integer)``
     81    IF gain is last gain stage on the RF tuner signal path. It is
     82    located on output of RF tuner. It controls signal level of
     83    intermediate frequency output or baseband output. Used when
     84    ``V4L2_CID_RF_TUNER_IF_GAIN_AUTO`` is not set. The range and step
     85    are driver-specific.
     86
     87``V4L2_CID_RF_TUNER_PLL_LOCK (boolean)``
     88    Is synthesizer PLL locked? RF tuner is receiving given frequency
     89    when that control is set. This is a read-only control.