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+<refentry id="media-ioc-device-info">
+ <refmeta>
+ <refentrytitle>ioctl MEDIA_IOC_DEVICE_INFO</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>MEDIA_IOC_DEVICE_INFO</refname>
+ <refpurpose>Query device information</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>int <function>ioctl</function></funcdef>
+ <paramdef>int <parameter>fd</parameter></paramdef>
+ <paramdef>int <parameter>request</parameter></paramdef>
+ <paramdef>struct media_device_info *<parameter>argp</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Arguments</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><parameter>fd</parameter></term>
+ <listitem>
+ <para>File descriptor returned by
+ <link linkend='media-func-open'><function>open()</function></link>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>request</parameter></term>
+ <listitem>
+ <para>MEDIA_IOC_DEVICE_INFO</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>argp</parameter></term>
+ <listitem>
+ <para></para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>All media devices must support the <constant>MEDIA_IOC_DEVICE_INFO</constant>
+ ioctl. To query device information, applications call the ioctl with a
+ pointer to a &media-device-info;. The driver fills the structure and returns
+ the information to the application.
+ The ioctl never fails.</para>
+
+ <table pgwide="1" frame="none" id="media-device-info">
+ <title>struct <structname>media_device_info</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>char</entry>
+ <entry><structfield>driver</structfield>[16]</entry>
+ <entry><para>Name of the driver implementing the media API as a
+ NUL-terminated ASCII string. The driver version is stored in the
+ <structfield>driver_version</structfield> field.</para>
+ <para>Driver specific applications can use this information to
+ verify the driver identity. It is also useful to work around
+ known bugs, or to identify drivers in error reports.</para></entry>
+ </row>
+ <row>
+ <entry>char</entry>
+ <entry><structfield>model</structfield>[32]</entry>
+ <entry>Device model name as a NUL-terminated UTF-8 string. The
+ device version is stored in the <structfield>device_version</structfield>
+ field and is not be appended to the model name.</entry>
+ </row>
+ <row>
+ <entry>char</entry>
+ <entry><structfield>serial</structfield>[40]</entry>
+ <entry>Serial number as a NUL-terminated ASCII string.</entry>
+ </row>
+ <row>
+ <entry>char</entry>
+ <entry><structfield>bus_info</structfield>[32]</entry>
+ <entry>Location of the device in the system as a NUL-terminated
+ ASCII string. This includes the bus type name (PCI, USB, ...) and a
+ bus-specific identifier.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>media_version</structfield></entry>
+ <entry>Media API version, formatted with the
+ <constant>KERNEL_VERSION()</constant> macro.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>hw_revision</structfield></entry>
+ <entry>Hardware device revision in a driver-specific format.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>media_version</structfield></entry>
+ <entry>Media device driver version, formatted with the
+ <constant>KERNEL_VERSION()</constant> macro. Together with the
+ <structfield>driver</structfield> field this identifies a particular
+ driver.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>reserved</structfield>[31]</entry>
+ <entry>Reserved for future extensions. Drivers and applications must
+ set this array to zero.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>The <structfield>serial</structfield> and <structfield>bus_info</structfield>
+ fields can be used to distinguish between multiple instances of otherwise
+ identical hardware. The serial number takes precedence when provided and can
+ be assumed to be unique. If the serial number is an empty string, the
+ <structfield>bus_info</structfield> field can be used instead. The
+ <structfield>bus_info</structfield> field is guaranteed to be unique, but
+ can vary across reboots or device unplug/replug.</para>
+ </refsect1>
+
+ <refsect1>
+ &return-value;
+ </refsect1>
+</refentry>