Documentation/linux_tv/media/dvb/fe-read-status.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _FE_READ_STATUS:
   4
   5 ********************
   6 ioctl FE_READ_STATUS
   7 ********************
   8
   9 *man FE_READ_STATUS(2)*
  10
  11 Returns status information about the front-end. This call only requires
  12 read-only access to the device
  13
  14
  15 Synopsis
  16 ========
  17
  18 .. c:function:: int ioctl( int fd, int request, unsigned int *status )
  19
  20 Arguments
  21 =========
  22
  23 ``fd``
  24     File descriptor returned by :ref:`open() <frontend_f_open>`.
  25
  26 ``request``
  27     FE_READ_STATUS
  28
  29 ``status``
  30     pointer to a bitmask integer filled with the values defined by enum
  31     :ref:`fe_status <fe-status>`.
  32
  33
  34 Description
  35 ===========
  36
  37 All DVB frontend devices support the ``FE_READ_STATUS`` ioctl. It is
  38 used to check about the locking status of the frontend after being
  39 tuned. The ioctl takes a pointer to an integer where the status will be
  40 written.
  41
  42 NOTE: the size of status is actually sizeof(enum fe_status), with
  43 varies according with the architecture. This needs to be fixed in the
  44 future.
  45
  46 RETURN VALUE
  47
  48 On success 0 is returned, on error -1 and the ``errno`` variable is set
  49 appropriately. The generic error codes are described at the
  50 :ref:`Generic Error Codes <gen-errors>` chapter.
  51
  52
  53 .. _fe-status-t:
  54
  55 int fe_status
  56 =============
  57
  58 The fe_status parameter is used to indicate the current state and/or
  59 state changes of the frontend hardware. It is produced using the enum
  60 :ref:`fe_status <fe-status>` values on a bitmask
  61
  62
  63 .. _fe-status:
  64
  65 .. flat-table:: enum fe_status
  66     :header-rows:  1
  67     :stub-columns: 0
  68
  69
  70     -  .. row 1
  71
  72        -  ID
  73
  74        -  Description
  75
  76     -  .. row 2
  77
  78        -  .. _`FE-HAS-SIGNAL`:
  79
  80           ``FE_HAS_SIGNAL``
  81
  82        -  The frontend has found something above the noise level
  83
  84     -  .. row 3
  85
  86        -  .. _`FE-HAS-CARRIER`:
  87
  88           ``FE_HAS_CARRIER``
  89
  90        -  The frontend has found a DVB signal
  91
  92     -  .. row 4
  93
  94        -  .. _`FE-HAS-VITERBI`:
  95
  96           ``FE_HAS_VITERBI``
  97
  98        -  The frontend FEC inner coding (Viterbi, LDPC or other inner code)
  99           is stable
 100
 101     -  .. row 5
 102
 103        -  .. _`FE-HAS-SYNC`:
 104
 105           ``FE_HAS_SYNC``
 106
 107        -  Synchronization bytes was found
 108
 109     -  .. row 6
 110
 111        -  .. _`FE-HAS-LOCK`:
 112
 113           ``FE_HAS_LOCK``
 114
 115        -  The DVB were locked and everything is working
 116
 117     -  .. row 7
 118
 119        -  .. _`FE-TIMEDOUT`:
 120
 121           ``FE_TIMEDOUT``
 122
 123        -  no lock within the last about 2 seconds
 124
 125     -  .. row 8
 126
 127        -  .. _`FE-REINIT`:
 128
 129           ``FE_REINIT``
 130
 131        -  The frontend was reinitialized, application is recommended to
 132           reset DiSEqC, tone and parameters
 133
 134
 135
 136
 137 .. ------------------------------------------------------------------------------
 138 .. This file was automatically converted from DocBook-XML with the dbxml
 139 .. library (https://github.com/return42/sphkerneldoc). The origin XML comes
 140 .. from the linux kernel, refer to:
 141 ..
 142 .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
 143 .. ------------------------------------------------------------------------------