Documentation/media/uapi/dvb/fe-read-snr.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _FE_READ_SNR:
   4
   5 ***********
   6 FE_READ_SNR
   7 ***********
   8
   9 Name
  10 ====
  11
  12 FE_READ_SNR
  13
  14
  15 Synopsis
  16 ========
  17
  18 .. cpp:function:: int  ioctl(int fd, int request = FE_READ_SNR, int16_t *snr)
  19
  20
  21 Arguments
  22 =========
  23
  24 .. flat-table::
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  26     :stub-columns: 0
  27
  28
  29     -  .. row 1
  30
  31        -  int fd
  32
  33        -  File descriptor returned by a previous call to open().
  34
  35     -  .. row 2
  36
  37        -  int request
  38
  39        -  Equals :ref:`FE_READ_SNR` for this command.
  40
  41     -  .. row 3
  42
  43        -  uint16_t \*snr
  44
  45        -  The signal-to-noise ratio is stored into \*snr.
  46
  47
  48 Description
  49 ===========
  50
  51 This ioctl call returns the signal-to-noise ratio for the signal
  52 currently received by the front-end. For this command, read-only access
  53 to the device is sufficient.
  54
  55
  56 Return Value
  57 ============
  58
  59 On success 0 is returned, on error -1 and the ``errno`` variable is set
  60 appropriately. The generic error codes are described at the
  61 :ref:`Generic Error Codes <gen-errors>` chapter.