| <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_ENTITY_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>ALSA, VBI and video nodes that carry the same media |
| stream</listitem> |
| <listitem>lens and flash controllers associated with a sensor</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_ENTITY_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_ENTITY_TYPE_DEVNODE</constant></entry> |
| <entry>Unknown device node</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_DEVNODE_V4L</constant></entry> |
| <entry>V4L video, radio or vbi device node</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_DEVNODE_FB</constant></entry> |
| <entry>Frame buffer device node</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_DEVNODE_ALSA</constant></entry> |
| <entry>ALSA card</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_DEVNODE_DVB</constant></entry> |
| <entry>DVB card</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_V4L2_SUBDEV</constant></entry> |
| <entry>Unknown V4L sub-device</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_V4L2_SUBDEV_SENSOR</constant></entry> |
| <entry>Video sensor</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_V4L2_SUBDEV_FLASH</constant></entry> |
| <entry>Flash controller</entry> |
| </row> |
| <row> |
| <entry><constant>MEDIA_ENTITY_TYPE_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_ENTITY_FLAG_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> |