e7121ab405
Those files are meant to be dual GPL 2.0 and GFDL without implicit sections. However, by a wrong cut-and-paste, I ended by applying a GPL 2+ license text to it, while still using the GPL 2.0 SPDX tag, with would cause an ambiguity about the licensing model. Solve this by explicitly mentioning that the dual licensing is between GPL 2.0 and GFDL and correcting the text. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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2.7 KiB
ReStructuredText
92 lines
2.7 KiB
ReStructuredText
.. This file is dual-licensed: you can use it either under the terms
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.. of the GPL 2.0 or the GFDL 1.1+ license, at your option. Note that this
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.. dual licensing only applies to this file, and not this project as a
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.. whole.
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..
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.. a) This file is free software; you can redistribute it and/or
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.. modify it under the terms of the GNU General Public License as
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.. published by the Free Software Foundation version 2 of
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.. the License.
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..
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.. This file is distributed in the hope that it will be useful,
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.. but WITHOUT ANY WARRANTY; without even the implied warranty of
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.. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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.. GNU General Public License for more details.
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..
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.. Or, alternatively,
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..
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.. b) Permission is granted to copy, distribute and/or modify this
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.. document under the terms of the GNU Free Documentation License,
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.. Version 1.1 or any later version published by the Free Software
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.. Foundation, with no Invariant Sections, no Front-Cover Texts
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.. and no Back-Cover Texts. A copy of the license is included at
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.. Documentation/media/uapi/fdl-appendix.rst.
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..
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.. TODO: replace it to GPL-2.0 OR GFDL-1.1-or-later WITH no-invariant-sections
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.. _request-func-ioctl:
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***************
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request ioctl()
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***************
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Name
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====
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request-ioctl - Control a request file descriptor
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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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.. c:function:: int ioctl( int fd, int cmd, void *argp )
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:name: req-ioctl
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Arguments
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=========
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``fd``
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File descriptor returned by :ref:`MEDIA_IOC_REQUEST_ALLOC`.
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``cmd``
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The request ioctl command code as defined in the media.h header file, for
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example :ref:`MEDIA_REQUEST_IOC_QUEUE`.
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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 :ref:`ioctl() <request-func-ioctl>` function manipulates request
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parameters. The argument ``fd`` must be an open file descriptor.
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The ioctl ``cmd`` code specifies the request 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 request ioctl commands and
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their parameters are located in the media.h header file. All request ioctl
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commands, their respective function and parameters are specified in
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:ref:`media-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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Command-specific error codes are listed in the individual command
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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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