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-rw-r--r-- | Documentation/userspace-api/media/mediactl/media-func-open.rst | 65 |
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diff --git a/Documentation/userspace-api/media/mediactl/media-func-open.rst b/Documentation/userspace-api/media/mediactl/media-func-open.rst new file mode 100644 index 000000000..24487cb0a --- /dev/null +++ b/Documentation/userspace-api/media/mediactl/media-func-open.rst @@ -0,0 +1,65 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: MC + +.. _media-func-open: + +************ +media open() +************ + +Name +==== + +media-open - Open a media 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 either ``O_RDONLY`` or ``O_RDWR``. + Other flags have no effect. + +Description +=========== + +To open a media 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 +are: + +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. |