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-rw-r--r-- | Documentation/media/uapi/cec/cec-func-open.rst | 78 |
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diff --git a/Documentation/media/uapi/cec/cec-func-open.rst b/Documentation/media/uapi/cec/cec-func-open.rst new file mode 100644 index 000000000..5d6663a64 --- /dev/null +++ b/Documentation/media/uapi/cec/cec-func-open.rst @@ -0,0 +1,78 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _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 ) + :name: cec-open + + +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() <cec-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() <cec-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. |