5fec921f49
As MEDIA_IOC_G_TOPOLOGY shares the data types already declared for entities, pads and links, we should move those to a separate part of the document, and use cross-references where needed. So, move the following tables to a separate section at the DocBook: media-entity-type media-entity-flag media-pad-flag media-link-flag Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
161 lines
5.0 KiB
XML
161 lines
5.0 KiB
XML
<refentry id="media-ioc-enum-links">
|
|
<refmeta>
|
|
<refentrytitle>ioctl MEDIA_IOC_ENUM_LINKS</refentrytitle>
|
|
&manvol;
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>MEDIA_IOC_ENUM_LINKS</refname>
|
|
<refpurpose>Enumerate all pads and links for a given entity</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_links_enum *<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_ENUM_LINKS</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><parameter>argp</parameter></term>
|
|
<listitem>
|
|
<para></para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>To enumerate pads and/or links for a given entity, applications set
|
|
the entity field of a &media-links-enum; structure and initialize the
|
|
&media-pad-desc; and &media-link-desc; structure arrays pointed by the
|
|
<structfield>pads</structfield> and <structfield>links</structfield> fields.
|
|
They then call the MEDIA_IOC_ENUM_LINKS ioctl with a pointer to this
|
|
structure.</para>
|
|
<para>If the <structfield>pads</structfield> field is not NULL, the driver
|
|
fills the <structfield>pads</structfield> array with information about the
|
|
entity's pads. The array must have enough room to store all the entity's
|
|
pads. The number of pads can be retrieved with the &MEDIA-IOC-ENUM-ENTITIES;
|
|
ioctl.</para>
|
|
<para>If the <structfield>links</structfield> field is not NULL, the driver
|
|
fills the <structfield>links</structfield> array with information about the
|
|
entity's outbound links. The array must have enough room to store all the
|
|
entity's outbound links. The number of outbound links can be retrieved with
|
|
the &MEDIA-IOC-ENUM-ENTITIES; ioctl.</para>
|
|
<para>Only forward links that originate at one of the entity's source pads
|
|
are returned during the enumeration process.</para>
|
|
|
|
<table pgwide="1" frame="none" id="media-links-enum">
|
|
<title>struct <structname>media_links_enum</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>entity</structfield></entry>
|
|
<entry>Entity id, set by the application.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&media-pad-desc;</entry>
|
|
<entry>*<structfield>pads</structfield></entry>
|
|
<entry>Pointer to a pads array allocated by the application. Ignored
|
|
if NULL.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&media-link-desc;</entry>
|
|
<entry>*<structfield>links</structfield></entry>
|
|
<entry>Pointer to a links array allocated by the application. Ignored
|
|
if NULL.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<table pgwide="1" frame="none" id="media-pad-desc">
|
|
<title>struct <structname>media_pad_desc</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>entity</structfield></entry>
|
|
<entry>ID of the entity this pad belongs to.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u16</entry>
|
|
<entry><structfield>index</structfield></entry>
|
|
<entry>0-based pad index.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>flags</structfield></entry>
|
|
<entry>Pad flags, see <xref linkend="media-pad-flag" /> for more details.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
<table pgwide="1" frame="none" id="media-link-desc">
|
|
<title>struct <structname>media_link_desc</structname></title>
|
|
<tgroup cols="3">
|
|
&cs-str;
|
|
<tbody valign="top">
|
|
<row>
|
|
<entry>&media-pad-desc;</entry>
|
|
<entry><structfield>source</structfield></entry>
|
|
<entry>Pad at the origin of this link.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>&media-pad-desc;</entry>
|
|
<entry><structfield>sink</structfield></entry>
|
|
<entry>Pad at the target of this link.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>__u32</entry>
|
|
<entry><structfield>flags</structfield></entry>
|
|
<entry>Link flags, see <xref linkend="media-link-flag" /> for more details.</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</table>
|
|
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
&return-value;
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><errorcode>EINVAL</errorcode></term>
|
|
<listitem>
|
|
<para>The &media-links-enum; <structfield>id</structfield> references
|
|
a non-existing entity.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect1>
|
|
</refentry>
|