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Diffstat (limited to 'Documentation/DocBook/media/v4l/media-ioc-g-topology.xml')
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diff --git a/Documentation/DocBook/media/v4l/media-ioc-g-topology.xml b/Documentation/DocBook/media/v4l/media-ioc-g-topology.xml new file mode 100644 index 000000000000..63152ab9efba --- /dev/null +++ b/Documentation/DocBook/media/v4l/media-ioc-g-topology.xml @@ -0,0 +1,394 @@ +<refentry id="media-g-topology"> + <refmeta> + <refentrytitle>ioctl MEDIA_IOC_G_TOPOLOGY</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>MEDIA_IOC_G_TOPOLOGY</refname> + <refpurpose>Enumerate the graph topology and graph element properties</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_v2_topology *<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_G_TOPOLOGY</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <para><emphasis role="bold">NOTE:</emphasis> This new ioctl is programmed to be added on Kernel 4.6. Its definition/arguments may change until its final version.</para> + + <para>The typical usage of this ioctl is to call it twice. + On the first call, the structure defined at &media-v2-topology; should + be zeroed. At return, if no errors happen, this ioctl will return the + <constant>topology_version</constant> and the total number of entities, + interfaces, pads and links.</para> + <para>Before the second call, the userspace should allocate arrays to + store the graph elements that are desired, putting the pointers to them + at the ptr_entities, ptr_interfaces, ptr_links and/or ptr_pads, keeping + the other values untouched.</para> + <para>If the <constant>topology_version</constant> remains the same, the + ioctl should fill the desired arrays with the media graph elements.</para> + + <table pgwide="1" frame="none" id="media-v2-topology"> + <title>struct <structname>media_v2_topology</structname></title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + <tbody valign="top"> + <row> + <entry>__u64</entry> + <entry><structfield>topology_version</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Version of the media graph topology. When the graph is + created, this field starts with zero. Every time a graph + element is added or removed, this field is + incremented.</entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>num_entities</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Number of entities in the graph</entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>ptr_entities</structfield></entry> + <entry></entry> + <entry></entry> + <entry>A pointer to a memory area where the entities array + will be stored, converted to a 64-bits integer. + It can be zero. if zero, the ioctl won't store the + entities. It will just update + <constant>num_entities</constant></entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>num_interfaces</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Number of interfaces in the graph</entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>ptr_interfaces</structfield></entry> + <entry></entry> + <entry></entry> + <entry>A pointer to a memory area where the interfaces array + will be stored, converted to a 64-bits integer. + It can be zero. if zero, the ioctl won't store the + interfaces. It will just update + <constant>num_interfaces</constant></entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>num_pads</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Total number of pads in the graph</entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>ptr_pads</structfield></entry> + <entry></entry> + <entry></entry> + <entry>A pointer to a memory area where the pads array + will be stored, converted to a 64-bits integer. + It can be zero. if zero, the ioctl won't store the + pads. It will just update + <constant>num_pads</constant></entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>num_links</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Total number of data and interface links in the graph</entry> + </row> + <row> + <entry>__u64</entry> + <entry><structfield>ptr_links</structfield></entry> + <entry></entry> + <entry></entry> + <entry>A pointer to a memory area where the links array + will be stored, converted to a 64-bits integer. + It can be zero. if zero, the ioctl won't store the + links. It will just update + <constant>num_links</constant></entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="media-v2-entity"> + <title>struct <structname>media_v2_entity</structname></title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>id</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Unique ID for the entity.</entry> + </row> + <row> + <entry>char</entry> + <entry><structfield>name</structfield>[64]</entry> + <entry></entry> + <entry></entry> + <entry>Entity name as an UTF-8 NULL-terminated string.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>function</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Entity main function, see <xref linkend="media-entity-type" /> for details.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[12]</entry> + <entry>Reserved for future extensions. Drivers and applications must + set this array to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="media-v2-interface"> + <title>struct <structname>media_v2_interface</structname></title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>id</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Unique ID for the interface.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>intf_type</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Interface type, see <xref linkend="media-intf-type" /> for details.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Interface flags. Currently unused.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[9]</entry> + <entry></entry> + <entry></entry> + <entry>Reserved for future extensions. Drivers and applications must + set this array to zero.</entry> + </row> + <row> + <entry>struct media_v2_intf_devnode</entry> + <entry><structfield>devnode</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Used only for device node interfaces. See <xref linkend="media-v2-intf-devnode" /> for details..</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="media-v2-intf-devnode"> + <title>struct <structname>media_v2_interface</structname></title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>major</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Device node major number.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>minor</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Device node minor number.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="media-v2-pad"> + <title>struct <structname>media_v2_pad</structname></title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>id</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Unique ID for the pad.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>entity_id</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Unique ID for the entity where this pad belongs.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Pad flags, see <xref linkend="media-pad-flag" /> for more details.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[9]</entry> + <entry></entry> + <entry></entry> + <entry>Reserved for future extensions. Drivers and applications must + set this array to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + <table pgwide="1" frame="none" id="media-v2-link"> + <title>struct <structname>media_v2_pad</structname></title> + <tgroup cols="5"> + <colspec colname="c1" /> + <colspec colname="c2" /> + <colspec colname="c3" /> + <colspec colname="c4" /> + <colspec colname="c5" /> + <tbody valign="top"> + <row> + <entry>__u32</entry> + <entry><structfield>id</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Unique ID for the pad.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>source_id</structfield></entry> + <entry></entry> + <entry></entry> + <entry> + <para>On pad to pad links: unique ID for the source pad.</para> + <para>On interface to entity links: unique ID for the interface.</para> + </entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>sink_id</structfield></entry> + <entry></entry> + <entry></entry> + <entry> + <para>On pad to pad links: unique ID for the sink pad.</para> + <para>On interface to entity links: unique ID for the entity.</para> + </entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry></entry> + <entry></entry> + <entry>Link flags, see <xref linkend="media-link-flag" /> for more details.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[5]</entry> + <entry></entry> + <entry></entry> + <entry>Reserved for future extensions. Drivers and applications must + set this array to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + </refsect1> + + <refsect1> + &return-value; + + <variablelist> + <varlistentry> + <term><errorcode>ENOSPC</errorcode></term> + <listitem> + <para>This is returned when either one or more of the num_entities, + num_interfaces, num_links or num_pads are non-zero and are smaller + than the actual number of elements inside the graph. This may happen + if the <constant>topology_version</constant> changed when compared + to the last time this ioctl was called. Userspace should usually + free the area for the pointers, zero the struct elements and call + this ioctl again.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> +</refentry> |