Documentation/media/uapi/dvb/fe-set-tone.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _FE_SET_TONE:
   4
   5 *****************
   6 ioctl FE_SET_TONE
   7 *****************
   8
   9 Name
  10 ====
  11
  12 FE_SET_TONE - Sets/resets the generation of the continuous 22kHz tone.
  13
  14
  15 Synopsis
  16 ========
  17
  18 .. cpp:function:: int ioctl( int fd, int request, enum fe_sec_tone_mode *tone )
  19
  20
  21 Arguments
  22 =========
  23
  24 ``fd``
  25     File descriptor returned by :ref:`open() <frontend_f_open>`.
  26
  27 ``request``
  28     FE_SET_TONE
  29
  30 ``tone``
  31     pointer to enum :ref:`fe_sec_tone_mode <fe-sec-tone-mode>`
  32
  33
  34 Description
  35 ===========
  36
  37 This ioctl is used to set the generation of the continuous 22kHz tone.
  38 This call requires read/write permissions.
  39
  40 Usually, satellite antenna subsystems require that the digital TV device
  41 to send a 22kHz tone in order to select between high/low band on some
  42 dual-band LNBf. It is also used to send signals to DiSEqC equipment, but
  43 this is done using the DiSEqC ioctls.
  44
  45 .. attention:: If more than one device is connected to the same antenna,
  46    setting a tone may interfere on other devices, as they may lose the
  47    capability of selecting the band. So, it is recommended that applications
  48    would change to SEC_TONE_OFF when the device is not used.
  49
  50 .. _fe-sec-tone-mode-t:
  51
  52 enum fe_sec_tone_mode
  53 =====================
  54
  55 .. _fe-sec-tone-mode:
  56
  57 .. flat-table:: enum fe_sec_tone_mode
  58     :header-rows:  1
  59     :stub-columns: 0
  60
  61
  62     -  .. row 1
  63
  64        -  ID
  65
  66        -  Description
  67
  68     -  .. row 2
  69
  70        -  .. _SEC-TONE-ON:
  71
  72           ``SEC_TONE_ON``
  73
  74        -  Sends a 22kHz tone burst to the antenna
  75
  76     -  .. row 3
  77
  78        -  .. _SEC-TONE-OFF:
  79
  80           ``SEC_TONE_OFF``
  81
  82        -  Don't send a 22kHz tone to the antenna (except if the
  83           FE_DISEQC_* ioctls are called)
  84
  85
  86 Return Value
  87 ============
  88
  89 On success 0 is returned, on error -1 and the ``errno`` variable is set
  90 appropriately. The generic error codes are described at the
  91 :ref:`Generic Error Codes <gen-errors>` chapter.