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Diffstat (limited to 'Documentation/DocBook/media/v4l/media-func-ioctl.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/media-func-ioctl.xml | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/media-func-ioctl.xml b/Documentation/DocBook/media/v4l/media-func-ioctl.xml new file mode 100644 index 00000000000..39478d0fbca --- /dev/null +++ b/Documentation/DocBook/media/v4l/media-func-ioctl.xml @@ -0,0 +1,73 @@ +<refentry id="media-func-ioctl"> + <refmeta> + <refentrytitle>media ioctl()</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>media-ioctl</refname> + <refpurpose>Control a media device</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <sys/ioctl.h></funcsynopsisinfo> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>void *<parameter>argp</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Arguments</title> + + <variablelist> + <varlistentry> + <term><parameter>fd</parameter></term> + <listitem> + <para>&fd;</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>request</parameter></term> + <listitem> + <para>Media ioctl request code as defined in the media.h header file, + for example MEDIA_IOC_SETUP_LINK.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para>Pointer to a request-specific structure.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + <para>The <function>ioctl()</function> function manipulates media device + parameters. The argument <parameter>fd</parameter> must be an open file + descriptor.</para> + <para>The ioctl <parameter>request</parameter> code specifies the media + function to be called. It has encoded in it whether the argument is an + input, output or read/write parameter, and the size of the argument + <parameter>argp</parameter> in bytes.</para> + <para>Macros and structures definitions specifying media ioctl requests and + their parameters are located in the media.h header file. All media ioctl + requests, their respective function and parameters are specified in + <xref linkend="media-user-func" />.</para> + </refsect1> + + <refsect1> + &return-value; + + <para>Request-specific error codes are listed in the + individual requests descriptions.</para> + <para>When an ioctl that takes an output or read/write parameter fails, + the parameter remains unmodified.</para> + </refsect1> +</refentry> |