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Diffstat (limited to 'Documentation/DocBook/v4l/media-ioc-enum-links.xml')
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1 files changed, 0 insertions, 207 deletions
diff --git a/Documentation/DocBook/v4l/media-ioc-enum-links.xml b/Documentation/DocBook/v4l/media-ioc-enum-links.xml deleted file mode 100644 index d2fc73e..0000000 --- a/Documentation/DocBook/v4l/media-ioc-enum-links.xml +++ /dev/null @@ -1,207 +0,0 @@ -<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>struct &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>struct &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 frame="none" pgwide="1" id="media-pad-flag"> - <title>Media pad flags</title> - <tgroup cols="2"> - <colspec colname="c1"/> - <colspec colname="c2"/> - <tbody valign="top"> - <row> - <entry><constant>MEDIA_PAD_FL_SINK</constant></entry> - <entry>Input pad, relative to the entity. Input pads sink data and - are targets of links.</entry> - </row> - <row> - <entry><constant>MEDIA_PAD_FL_SOURCE</constant></entry> - <entry>Output pad, relative to the entity. Output pads source data - and are origins of links.</entry> - </row> - </tbody> - </tgroup> - </table> - - <table pgwide="1" frame="none" id="media-link-desc"> - <title>struct <structname>media_links_desc</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>struct &media-pad-desc;</entry> - <entry><structfield>source</structfield></entry> - <entry>Pad at the origin of this link.</entry> - </row> - <row> - <entry>struct &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> - - <table frame="none" pgwide="1" id="media-link-flag"> - <title>Media link flags</title> - <tgroup cols="2"> - <colspec colname="c1"/> - <colspec colname="c2"/> - <tbody valign="top"> - <row> - <entry><constant>MEDIA_LNK_FL_ENABLED</constant></entry> - <entry>The link is enabled and can be used to transfer media data. - When two or more links target a sink pad, only one of them can be - enabled at a time.</entry> - </row> - <row> - <entry><constant>MEDIA_LNK_FL_IMMUTABLE</constant></entry> - <entry>The link enabled state can't be modified at runtime. An - immutable link is always enabled.</entry> - </row> - <row> - <entry><constant>MEDIA_LNK_FL_DYNAMIC</constant></entry> - <entry>The link enabled state can be modified during streaming. This - flag is set by drivers and is read-only for applications.</entry> - </row> - </tbody> - </tgroup> - </table> - <para>One and only one of <constant>MEDIA_PAD_FL_SINK</constant> and - <constant>MEDIA_PAD_FL_SOURCE</constant> must be set for every pad.</para> - </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> |