tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1.. -*- coding: utf-8; mode: rst -*-
2
3.. _cec-func-open:
4
5**********
6cec open()
7**********
8
9Name
10====
11
12cec-open - Open a cec device
13
14Synopsis
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 :name: cec-open
24
25
26Arguments
27=========
28
29``device_name``
30 Device to be opened.
31
32``flags``
33 Open flags. Access mode must be ``O_RDWR``.
34
35 When the ``O_NONBLOCK`` flag is given, the
36 :ref:`CEC_RECEIVE <CEC_RECEIVE>` and :ref:`CEC_DQEVENT <CEC_DQEVENT>` ioctls
37 will return the ``EAGAIN`` error code when no message or event is available, and
38 ioctls :ref:`CEC_TRANSMIT <CEC_TRANSMIT>`,
39 :ref:`CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` and
40 :ref:`CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`
41 all return 0.
42
43 Other flags have no effect.
44
45
46Description
47===========
48
49To open a cec device applications call :c:func:`open() <cec-open>` with the
50desired device name. The function has no side effects; the device
51configuration remain unchanged.
52
53When the device is opened in read-only mode, attempts to modify its
54configuration will result in an error, and ``errno`` will be set to
55EBADF.
56
57
58Return Value
59============
60
61:c:func:`open() <cec-open>` returns the new file descriptor on success. On error,
62-1 is returned, and ``errno`` is set appropriately. Possible error codes
63include:
64
65``EACCES``
66 The requested access to the file is not allowed.
67
68``EMFILE``
69 The process already has the maximum number of files open.
70
71``ENFILE``
72 The system limit on the total number of open files has been reached.
73
74``ENOMEM``
75 Insufficient kernel memory was available.
76
77``ENXIO``
78 No device corresponding to this device special file exists.