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1651333b LP |
1 | <refentry id="media-ioc-enum-entities"> |
2 | <refmeta> | |
3 | <refentrytitle>ioctl MEDIA_IOC_ENUM_ENTITIES</refentrytitle> | |
4 | &manvol; | |
5 | </refmeta> | |
6 | ||
7 | <refnamediv> | |
8 | <refname>MEDIA_IOC_ENUM_ENTITIES</refname> | |
9 | <refpurpose>Enumerate entities and their properties</refpurpose> | |
10 | </refnamediv> | |
11 | ||
12 | <refsynopsisdiv> | |
13 | <funcsynopsis> | |
14 | <funcprototype> | |
15 | <funcdef>int <function>ioctl</function></funcdef> | |
16 | <paramdef>int <parameter>fd</parameter></paramdef> | |
17 | <paramdef>int <parameter>request</parameter></paramdef> | |
18 | <paramdef>struct media_entity_desc *<parameter>argp</parameter></paramdef> | |
19 | </funcprototype> | |
20 | </funcsynopsis> | |
21 | </refsynopsisdiv> | |
22 | ||
23 | <refsect1> | |
24 | <title>Arguments</title> | |
25 | ||
26 | <variablelist> | |
27 | <varlistentry> | |
28 | <term><parameter>fd</parameter></term> | |
29 | <listitem> | |
30 | <para>File descriptor returned by | |
31 | <link linkend='media-func-open'><function>open()</function></link>.</para> | |
32 | </listitem> | |
33 | </varlistentry> | |
34 | <varlistentry> | |
35 | <term><parameter>request</parameter></term> | |
36 | <listitem> | |
37 | <para>MEDIA_IOC_ENUM_ENTITIES</para> | |
38 | </listitem> | |
39 | </varlistentry> | |
40 | <varlistentry> | |
41 | <term><parameter>argp</parameter></term> | |
42 | <listitem> | |
43 | <para></para> | |
44 | </listitem> | |
45 | </varlistentry> | |
46 | </variablelist> | |
47 | </refsect1> | |
48 | ||
49 | <refsect1> | |
50 | <title>Description</title> | |
51 | <para>To query the attributes of an entity, applications set the id field | |
52 | of a &media-entity-desc; structure and call the MEDIA_IOC_ENUM_ENTITIES | |
53 | ioctl with a pointer to this structure. The driver fills the rest of the | |
54 | structure or returns an &EINVAL; when the id is invalid.</para> | |
55 | <para>Entities can be enumerated by or'ing the id with the | |
56 | <constant>MEDIA_ENT_ID_FLAG_NEXT</constant> flag. The driver will return | |
57 | information about the entity with the smallest id strictly larger than the | |
58 | requested one ('next entity'), or the &EINVAL; if there is none.</para> | |
59 | <para>Entity IDs can be non-contiguous. Applications must | |
60 | <emphasis>not</emphasis> try to enumerate entities by calling | |
61 | MEDIA_IOC_ENUM_ENTITIES with increasing id's until they get an error.</para> | |
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62 | |
63 | <table pgwide="1" frame="none" id="media-entity-desc"> | |
64 | <title>struct <structname>media_entity_desc</structname></title> | |
65 | <tgroup cols="5"> | |
66 | <colspec colname="c1" /> | |
67 | <colspec colname="c2" /> | |
68 | <colspec colname="c3" /> | |
69 | <colspec colname="c4" /> | |
70 | <colspec colname="c5" /> | |
71 | <tbody valign="top"> | |
72 | <row> | |
73 | <entry>__u32</entry> | |
74 | <entry><structfield>id</structfield></entry> | |
75 | <entry></entry> | |
76 | <entry></entry> | |
77 | <entry>Entity id, set by the application. When the id is or'ed with | |
78 | <constant>MEDIA_ENT_ID_FLAG_NEXT</constant>, the driver clears the | |
79 | flag and returns the first entity with a larger id.</entry> | |
80 | </row> | |
81 | <row> | |
82 | <entry>char</entry> | |
83 | <entry><structfield>name</structfield>[32]</entry> | |
84 | <entry></entry> | |
85 | <entry></entry> | |
86 | <entry>Entity name as an UTF-8 NULL-terminated string.</entry> | |
87 | </row> | |
88 | <row> | |
89 | <entry>__u32</entry> | |
90 | <entry><structfield>type</structfield></entry> | |
91 | <entry></entry> | |
92 | <entry></entry> | |
93 | <entry>Entity type, see <xref linkend="media-entity-type" /> for details.</entry> | |
94 | </row> | |
95 | <row> | |
96 | <entry>__u32</entry> | |
97 | <entry><structfield>revision</structfield></entry> | |
98 | <entry></entry> | |
99 | <entry></entry> | |
8ed8c88c | 100 | <entry>Entity revision. Always zero (obsolete)</entry> |
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101 | </row> |
102 | <row> | |
103 | <entry>__u32</entry> | |
104 | <entry><structfield>flags</structfield></entry> | |
105 | <entry></entry> | |
106 | <entry></entry> | |
107 | <entry>Entity flags, see <xref linkend="media-entity-flag" /> for details.</entry> | |
108 | </row> | |
109 | <row> | |
110 | <entry>__u32</entry> | |
111 | <entry><structfield>group_id</structfield></entry> | |
112 | <entry></entry> | |
113 | <entry></entry> | |
8ed8c88c | 114 | <entry>Entity group ID. Always zero (obsolete)</entry> |
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115 | </row> |
116 | <row> | |
117 | <entry>__u16</entry> | |
118 | <entry><structfield>pads</structfield></entry> | |
119 | <entry></entry> | |
120 | <entry></entry> | |
121 | <entry>Number of pads</entry> | |
122 | </row> | |
123 | <row> | |
124 | <entry>__u16</entry> | |
125 | <entry><structfield>links</structfield></entry> | |
126 | <entry></entry> | |
127 | <entry></entry> | |
128 | <entry>Total number of outbound links. Inbound links are not counted | |
129 | in this field.</entry> | |
130 | </row> | |
131 | <row> | |
132 | <entry>union</entry> | |
133 | </row> | |
134 | <row> | |
135 | <entry></entry> | |
136 | <entry>struct</entry> | |
15d20421 | 137 | <entry><structfield>dev</structfield></entry> |
1651333b | 138 | <entry></entry> |
7e182f78 HV |
139 | <entry>Valid for (sub-)devices that create a single device node.</entry> |
140 | </row> | |
141 | <row> | |
142 | <entry></entry> | |
143 | <entry></entry> | |
144 | <entry>__u32</entry> | |
145 | <entry><structfield>major</structfield></entry> | |
146 | <entry>Device node major number.</entry> | |
147 | </row> | |
148 | <row> | |
149 | <entry></entry> | |
150 | <entry></entry> | |
151 | <entry>__u32</entry> | |
152 | <entry><structfield>minor</structfield></entry> | |
153 | <entry>Device node minor number.</entry> | |
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154 | </row> |
155 | <row> | |
156 | <entry></entry> | |
157 | <entry>__u8</entry> | |
15d20421 | 158 | <entry><structfield>raw</structfield>[184]</entry> |
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159 | <entry></entry> |
160 | <entry></entry> | |
161 | </row> | |
162 | </tbody> | |
163 | </tgroup> | |
164 | </table> | |
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165 | </refsect1> |
166 | ||
167 | <refsect1> | |
168 | &return-value; | |
169 | ||
170 | <variablelist> | |
171 | <varlistentry> | |
172 | <term><errorcode>EINVAL</errorcode></term> | |
173 | <listitem> | |
174 | <para>The &media-entity-desc; <structfield>id</structfield> references | |
175 | a non-existing entity.</para> | |
176 | </listitem> | |
177 | </varlistentry> | |
178 | </variablelist> | |
179 | </refsect1> | |
180 | </refentry> |