tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: CEC
3
4.. _cec-func-open:
5
6**********
7cec open()
8**********
9
10Name
11====
12
13cec-open - Open a cec device
14
15Synopsis
16========
17
18.. code-block:: c
19
20 #include <fcntl.h>
21
22.. c:function:: int open( const char *device_name, int flags )
23
24Arguments
25=========
26
27``device_name``
28 Device to be opened.
29
30``flags``
31 Open flags. Access mode must be ``O_RDWR``.
32
33 When the ``O_NONBLOCK`` flag is given, the
34 :ref:`CEC_RECEIVE <CEC_RECEIVE>` and :ref:`CEC_DQEVENT <CEC_DQEVENT>` ioctls
35 will return the ``EAGAIN`` error code when no message or event is available, and
36 ioctls :ref:`CEC_TRANSMIT <CEC_TRANSMIT>`,
37 :ref:`CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` and
38 :ref:`CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`
39 all return 0.
40
41 Other flags have no effect.
42
43Description
44===========
45
46To open a cec device applications call :c:func:`open()` with the
47desired device name. The function has no side effects; the device
48configuration remain unchanged.
49
50When the device is opened in read-only mode, attempts to modify its
51configuration will result in an error, and ``errno`` will be set to
52EBADF.
53
54Return Value
55============
56
57:c:func:`open()` returns the new file descriptor on success. On error,
58-1 is returned, and ``errno`` is set appropriately. Possible error codes
59include:
60
61``EACCES``
62 The requested access to the file is not allowed.
63
64``EMFILE``
65 The process already has the maximum number of files open.
66
67``ENFILE``
68 The system limit on the total number of open files has been reached.
69
70``ENOMEM``
71 Insufficient kernel memory was available.
72
73``ENXIO``
74 No device corresponding to this device special file exists.