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