Documentation/media/uapi/dvb/fe-get-property.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _FE_GET_PROPERTY:
   4
   5 **************************************
   6 ioctl FE_SET_PROPERTY, FE_GET_PROPERTY
   7 **************************************
   8
   9 Name
  10 ====
  11
  12 FE_SET_PROPERTY - FE_GET_PROPERTY - FE_SET_PROPERTY sets one or more frontend properties. - FE_GET_PROPERTY returns one or more frontend properties.
  13
  14
  15 Synopsis
  16 ========
  17
  18 .. cpp:function:: int ioctl( int fd, int request, struct dtv_properties *argp )
  19
  20
  21 Arguments
  22 =========
  23
  24 ``fd``
  25     File descriptor returned by :ref:`open() <frontend_f_open>`.
  26
  27 ``request``
  28     FE_SET_PROPERTY, FE_GET_PROPERTY
  29
  30 ``argp``
  31     pointer to struct :ref:`dtv_properties <dtv-properties>`
  32
  33
  34 Description
  35 ===========
  36
  37 All DVB frontend devices support the ``FE_SET_PROPERTY`` and
  38 ``FE_GET_PROPERTY`` ioctls. The supported properties and statistics
  39 depends on the delivery system and on the device:
  40
  41 -  ``FE_SET_PROPERTY:``
  42
  43    -  This ioctl is used to set one or more frontend properties.
  44
  45    -  This is the basic command to request the frontend to tune into
  46       some frequency and to start decoding the digital TV signal.
  47
  48    -  This call requires read/write access to the device.
  49
  50    -  At return, the values are updated to reflect the actual parameters
  51       used.
  52
  53 -  ``FE_GET_PROPERTY:``
  54
  55    -  This ioctl is used to get properties and statistics from the
  56       frontend.
  57
  58    -  No properties are changed, and statistics aren't reset.
  59
  60    -  This call only requires read-only access to the device.
  61
  62
  63 Return Value
  64 ============
  65
  66 On success 0 is returned, on error -1 and the ``errno`` variable is set
  67 appropriately. The generic error codes are described at the
  68 :ref:`Generic Error Codes <gen-errors>` chapter.