Documentation/linux_tv/media/v4l/media-func-open.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _media-func-open:
   4
   5 ************
   6 media open()
   7 ************
   8
   9 *man media-open(2)*
  10
  11 Open a media device
  12
  13
  14 Synopsis
  15 ========
  16
  17 .. code-block:: c
  18
  19     #include <fcntl.h>
  20
  21
  22 .. c:function:: int open( const char *device_name, int flags )
  23
  24 Arguments
  25 =========
  26
  27 ``device_name``
  28     Device to be opened.
  29
  30 ``flags``
  31     Open flags. Access mode must be either ``O_RDONLY`` or ``O_RDWR``.
  32     Other flags have no effect.
  33
  34
  35 Description
  36 ===========
  37
  38 To open a media device applications call :c:func:`open()` with the
  39 desired device name. The function has no side effects; the device
  40 configuration remain unchanged.
  41
  42 When the device is opened in read-only mode, attempts to modify its
  43 configuration will result in an error, and ``errno`` will be set to
  44 EBADF.
  45
  46
  47 Return Value
  48 ============
  49
  50 :c:func:`open()` returns the new file descriptor on success. On error,
  51 -1 is returned, and ``errno`` is set appropriately. Possible error codes
  52 are:
  53
  54 EACCES
  55     The requested access to the file is not allowed.
  56
  57 EMFILE
  58     The process already has the maximum number of files open.
  59
  60 ENFILE
  61     The system limit on the total number of open files has been reached.
  62
  63 ENOMEM
  64     Insufficient kernel memory was available.
  65
  66 ENXIO
  67     No device corresponding to this device special file exists.
  68
  69
  70 .. ------------------------------------------------------------------------------
  71 .. This file was automatically converted from DocBook-XML with the dbxml
  72 .. library (https://github.com/return42/sphkerneldoc). The origin XML comes
  73 .. from the linux kernel, refer to:
  74 ..
  75 .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
  76 .. ------------------------------------------------------------------------------