aboutsummaryrefslogtreecommitdiff
path: root/Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml')
-rw-r--r--Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml308
1 files changed, 308 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml b/Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml
new file mode 100644
index 00000000..576b68b3
--- /dev/null
+++ b/Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml
@@ -0,0 +1,308 @@
+<refentry id="media-ioc-enum-entities">
+ <refmeta>
+ <refentrytitle>ioctl MEDIA_IOC_ENUM_ENTITIES</refentrytitle>
+ &manvol;
+ </refmeta>
+
+ <refnamediv>
+ <refname>MEDIA_IOC_ENUM_ENTITIES</refname>
+ <refpurpose>Enumerate entities and their 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_entity_desc *<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_ENTITIES</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>argp</parameter></term>
+ <listitem>
+ <para></para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Description</title>
+ <para>To query the attributes of an entity, applications set the id field
+ of a &media-entity-desc; structure and call the MEDIA_IOC_ENUM_ENTITIES
+ ioctl with a pointer to this structure. The driver fills the rest of the
+ structure or returns an &EINVAL; when the id is invalid.</para>
+ <para>Entities can be enumerated by or'ing the id with the
+ <constant>MEDIA_ENT_ID_FLAG_NEXT</constant> flag. The driver will return
+ information about the entity with the smallest id strictly larger than the
+ requested one ('next entity'), or the &EINVAL; if there is none.</para>
+ <para>Entity IDs can be non-contiguous. Applications must
+ <emphasis>not</emphasis> try to enumerate entities by calling
+ MEDIA_IOC_ENUM_ENTITIES with increasing id's until they get an error.</para>
+ <para>Two or more entities that share a common non-zero
+ <structfield>group_id</structfield> value are considered as logically
+ grouped. Groups are used to report
+ <itemizedlist>
+ <listitem><para>ALSA, VBI and video nodes that carry the same media
+ stream</para></listitem>
+ <listitem><para>lens and flash controllers associated with a sensor</para></listitem>
+ </itemizedlist>
+ </para>
+
+ <table pgwide="1" frame="none" id="media-entity-desc">
+ <title>struct <structname>media_entity_desc</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>Entity id, set by the application. When the id is or'ed with
+ <constant>MEDIA_ENT_ID_FLAG_NEXT</constant>, the driver clears the
+ flag and returns the first entity with a larger id.</entry>
+ </row>
+ <row>
+ <entry>char</entry>
+ <entry><structfield>name</structfield>[32]</entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Entity name as an UTF-8 NULL-terminated string.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>type</structfield></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Entity type, see <xref linkend="media-entity-type" /> for details.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>revision</structfield></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Entity revision in a driver/hardware specific format.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>flags</structfield></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Entity flags, see <xref linkend="media-entity-flag" /> for details.</entry>
+ </row>
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>group_id</structfield></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Entity group ID</entry>
+ </row>
+ <row>
+ <entry>__u16</entry>
+ <entry><structfield>pads</structfield></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Number of pads</entry>
+ </row>
+ <row>
+ <entry>__u16</entry>
+ <entry><structfield>links</structfield></entry>
+ <entry></entry>
+ <entry></entry>
+ <entry>Total number of outbound links. Inbound links are not counted
+ in this field.</entry>
+ </row>
+ <row>
+ <entry>union</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>struct</entry>
+ <entry><structfield>v4l</structfield></entry>
+ <entry></entry>
+ <entry>Valid for V4L sub-devices and nodes only.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>major</structfield></entry>
+ <entry>V4L device node major number. For V4L sub-devices with no
+ device node, set by the driver to 0.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>minor</structfield></entry>
+ <entry>V4L device node minor number. For V4L sub-devices with no
+ device node, set by the driver to 0.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>struct</entry>
+ <entry><structfield>fb</structfield></entry>
+ <entry></entry>
+ <entry>Valid for frame buffer nodes only.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>major</structfield></entry>
+ <entry>Frame buffer device node major number.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>minor</structfield></entry>
+ <entry>Frame buffer device node minor number.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>struct</entry>
+ <entry><structfield>alsa</structfield></entry>
+ <entry></entry>
+ <entry>Valid for ALSA devices only.</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>card</structfield></entry>
+ <entry>ALSA card number</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>device</structfield></entry>
+ <entry>ALSA device number</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry></entry>
+ <entry>__u32</entry>
+ <entry><structfield>subdevice</structfield></entry>
+ <entry>ALSA sub-device number</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>int</entry>
+ <entry><structfield>dvb</structfield></entry>
+ <entry></entry>
+ <entry>DVB card number</entry>
+ </row>
+ <row>
+ <entry></entry>
+ <entry>__u8</entry>
+ <entry><structfield>raw</structfield>[180]</entry>
+ <entry></entry>
+ <entry></entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <table frame="none" pgwide="1" id="media-entity-type">
+ <title>Media entity types</title>
+ <tgroup cols="2">
+ <colspec colname="c1"/>
+ <colspec colname="c2"/>
+ <tbody valign="top">
+ <row>
+ <entry><constant>MEDIA_ENT_T_DEVNODE</constant></entry>
+ <entry>Unknown device node</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_DEVNODE_V4L</constant></entry>
+ <entry>V4L video, radio or vbi device node</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_DEVNODE_FB</constant></entry>
+ <entry>Frame buffer device node</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_DEVNODE_ALSA</constant></entry>
+ <entry>ALSA card</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_DEVNODE_DVB</constant></entry>
+ <entry>DVB card</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_V4L2_SUBDEV</constant></entry>
+ <entry>Unknown V4L sub-device</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_SENSOR</constant></entry>
+ <entry>Video sensor</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_FLASH</constant></entry>
+ <entry>Flash controller</entry>
+ </row>
+ <row>
+ <entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_LENS</constant></entry>
+ <entry>Lens controller</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <table frame="none" pgwide="1" id="media-entity-flag">
+ <title>Media entity flags</title>
+ <tgroup cols="2">
+ <colspec colname="c1"/>
+ <colspec colname="c2"/>
+ <tbody valign="top">
+ <row>
+ <entry><constant>MEDIA_ENT_FL_DEFAULT</constant></entry>
+ <entry>Default entity for its type. Used to discover the default
+ audio, VBI and video devices, the default camera sensor, ...</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </refsect1>
+
+ <refsect1>
+ &return-value;
+
+ <variablelist>
+ <varlistentry>
+ <term><errorcode>EINVAL</errorcode></term>
+ <listitem>
+ <para>The &media-entity-desc; <structfield>id</structfield> references
+ a non-existing entity.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+</refentry>