Documentation/userspace-api/media/cec/cec-func-open.rst
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: CEC
.. _cec-func-open:
cec open()
cec-open - Open a cec device
.. code-block:: c
#include <fcntl.h>
.. c:function:: int open( const char *device_name, int flags )
device_name
Device to be opened.
flags
Open flags. Access mode must be O_RDWR.
When the ``O_NONBLOCK`` flag is given, the
:ref:`CEC_RECEIVE <CEC_RECEIVE>` and :ref:`CEC_DQEVENT <CEC_DQEVENT>` ioctls
will return the ``EAGAIN`` error code when no message or event is available, and
ioctls :ref:`CEC_TRANSMIT <CEC_TRANSMIT>`,
:ref:`CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` and
:ref:`CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`
all return 0.
Other flags have no effect.
To open a cec device applications call :c:func:open() with the
desired device name. The function has no side effects; the device
configuration remain unchanged.
When the device is opened in read-only mode, attempts to modify its
configuration will result in an error, and errno will be set to
EBADF.
:c:func:open() returns the new file descriptor on success. On error,
-1 is returned, and errno is set appropriately. Possible error codes
include:
EACCES
The requested access to the file is not allowed.
EMFILE
The process already has the maximum number of files open.
ENFILE
The system limit on the total number of open files has been reached.
ENOMEM
Insufficient kernel memory was available.
ENODEV
Device not found or was removed.