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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/cec/cec-func-open.rst | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/cec/cec-func-open.rst')
-rw-r--r-- | Documentation/userspace-api/media/cec/cec-func-open.rst | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/cec/cec-func-open.rst b/Documentation/userspace-api/media/cec/cec-func-open.rst new file mode 100644 index 000000000..d86563a34 --- /dev/null +++ b/Documentation/userspace-api/media/cec/cec-func-open.rst @@ -0,0 +1,74 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: CEC + +.. _cec-func-open: + +********** +cec open() +********** + +Name +==== + +cec-open - Open a cec device + +Synopsis +======== + +.. code-block:: c + + #include <fcntl.h> + +.. c:function:: int open( const char *device_name, int flags ) + +Arguments +========= + +``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. + +Description +=========== + +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. + +Return Value +============ + +: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. + +``ENXIO`` + No device corresponding to this device special file exists. |