dfcf4f9d97
Instead of having their own generic error codes at the MC API, move its section to the generic one and be sure that all media ioctl's will point to it. Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
73 lines
2.3 KiB
XML
73 lines
2.3 KiB
XML
<refentry id="media-func-ioctl">
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<refmeta>
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<refentrytitle>media ioctl()</refentrytitle>
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&manvol;
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</refmeta>
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<refnamediv>
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<refname>media-ioctl</refname>
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<refpurpose>Control a media device</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>#include <sys/ioctl.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>int <function>ioctl</function></funcdef>
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<paramdef>int <parameter>fd</parameter></paramdef>
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<paramdef>int <parameter>request</parameter></paramdef>
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<paramdef>void *<parameter>argp</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Arguments</title>
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<variablelist>
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<varlistentry>
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<term><parameter>fd</parameter></term>
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<listitem>
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<para>&fd;</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>request</parameter></term>
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<listitem>
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<para>Media ioctl request code as defined in the media.h header file,
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for example MEDIA_IOC_SETUP_LINK.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>argp</parameter></term>
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<listitem>
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<para>Pointer to a request-specific structure.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>Description</title>
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<para>The <function>ioctl()</function> function manipulates media device
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parameters. The argument <parameter>fd</parameter> must be an open file
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descriptor.</para>
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<para>The ioctl <parameter>request</parameter> code specifies the media
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function to be called. It has encoded in it whether the argument is an
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input, output or read/write parameter, and the size of the argument
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<parameter>argp</parameter> in bytes.</para>
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<para>Macros and structures definitions specifying media ioctl requests and
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their parameters are located in the media.h header file. All media ioctl
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requests, their respective function and parameters are specified in
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<xref linkend="media-user-func" />.</para>
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</refsect1>
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<refsect1>
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&return-value;
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<para>Request-specific error codes are listed in the
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individual requests descriptions.</para>
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<para>When an ioctl that takes an output or read/write parameter fails,
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the parameter remains unmodified.</para>
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</refsect1>
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</refentry>
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