Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
64 lines
1.5 KiB
ReStructuredText
64 lines
1.5 KiB
ReStructuredText
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
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.. c:namespace:: CEC
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.. _cec-func-ioctl:
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***********
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cec ioctl()
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***********
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Name
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====
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cec-ioctl - Control a cec device
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Synopsis
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========
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.. code-block:: c
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#include <sys/ioctl.h>
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``int ioctl(int fd, int request, void *argp)``
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Arguments
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=========
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``fd``
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File descriptor returned by :c:func:`open()`.
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``request``
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CEC ioctl request code as defined in the cec.h header file, for
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example :ref:`CEC_ADAP_G_CAPS <CEC_ADAP_G_CAPS>`.
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``argp``
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Pointer to a request-specific structure.
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Description
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===========
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The :c:func:`ioctl()` function manipulates cec device parameters. The
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argument ``fd`` must be an open file descriptor.
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The ioctl ``request`` code specifies the cec function to be called. It
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has encoded in it whether the argument is an input, output or read/write
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parameter, and the size of the argument ``argp`` in bytes.
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Macros and structures definitions specifying cec ioctl requests and
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their parameters are located in the cec.h header file. All cec ioctl
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requests, their respective function and parameters are specified in
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:ref:`cec-user-func`.
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Return Value
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============
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On success 0 is returned, on error -1 and the ``errno`` variable is set
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appropriately. The generic error codes are described at the
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:ref:`Generic Error Codes <gen-errors>` chapter.
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Request-specific error codes are listed in the individual requests
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descriptions.
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When an ioctl that takes an output or read/write parameter fails, the
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parameter remains unmodified.
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