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1 | .. -*- coding: utf-8; mode: rst -*- |
2 | ||
d2c68150 | 3 | .. _media_ioc_enum_entities: |
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4 | |
5 | ***************************** | |
6 | ioctl MEDIA_IOC_ENUM_ENTITIES | |
7 | ***************************** | |
8 | ||
15e7d615 | 9 | Name |
586027ce | 10 | ==== |
5377d91f | 11 | |
586027ce | 12 | MEDIA_IOC_ENUM_ENTITIES - Enumerate entities and their properties |
5377d91f | 13 | |
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14 | |
15 | Synopsis | |
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16 | ======== |
17 | ||
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18 | .. c:function:: int ioctl( int fd, MEDIA_IOC_ENUM_ENTITIES, struct media_entity_desc *argp ) |
19 | :name: MEDIA_IOC_ENUM_ENTITIES | |
5377d91f | 20 | |
586027ce | 21 | |
15e7d615 | 22 | Arguments |
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23 | ========= |
24 | ||
25 | ``fd`` | |
26 | File descriptor returned by :ref:`open() <media-func-open>`. | |
27 | ||
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28 | ``argp`` |
29 | ||
30 | ||
15e7d615 | 31 | Description |
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32 | =========== |
33 | ||
34 | To query the attributes of an entity, applications set the id field of a | |
e8be7e97 | 35 | struct :c:type:`media_entity_desc` structure and |
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36 | call the MEDIA_IOC_ENUM_ENTITIES ioctl with a pointer to this |
37 | structure. The driver fills the rest of the structure or returns an | |
38 | EINVAL error code when the id is invalid. | |
39 | ||
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40 | .. _media-ent-id-flag-next: |
41 | ||
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42 | Entities can be enumerated by or'ing the id with the |
43 | ``MEDIA_ENT_ID_FLAG_NEXT`` flag. The driver will return information | |
44 | about the entity with the smallest id strictly larger than the requested | |
cdb4af0f | 45 | one ('next entity'), or the ``EINVAL`` error code if there is none. |
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46 | |
47 | Entity IDs can be non-contiguous. Applications must *not* try to | |
48 | enumerate entities by calling MEDIA_IOC_ENUM_ENTITIES with increasing | |
49 | id's until they get an error. | |
50 | ||
51 | ||
e8be7e97 | 52 | .. c:type:: media_entity_desc |
5377d91f | 53 | |
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54 | .. tabularcolumns:: |p{1.5cm}|p{1.5cm}|p{1.5cm}|p{1.5cm}|p{11.5cm}| |
55 | ||
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56 | .. flat-table:: struct media_entity_desc |
57 | :header-rows: 0 | |
58 | :stub-columns: 0 | |
2ceb5d7b | 59 | :widths: 1 1 1 1 8 |
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60 | |
61 | ||
62 | - .. row 1 | |
63 | ||
64 | - __u32 | |
65 | ||
66 | - ``id`` | |
67 | ||
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68 | - |
69 | - | |
5377d91f | 70 | - Entity id, set by the application. When the id is or'ed with |
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71 | ``MEDIA_ENT_ID_FLAG_NEXT``, the driver clears the flag and returns |
72 | the first entity with a larger id. | |
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73 | |
74 | - .. row 2 | |
75 | ||
76 | - char | |
77 | ||
8968da9b | 78 | - ``name``\ [32] |
5377d91f | 79 | |
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80 | - |
81 | - | |
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82 | - Entity name as an UTF-8 NULL-terminated string. |
83 | ||
84 | - .. row 3 | |
85 | ||
86 | - __u32 | |
87 | ||
88 | - ``type`` | |
89 | ||
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90 | - |
91 | - | |
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92 | - Entity type, see :ref:`media-entity-type` for details. |
93 | ||
94 | - .. row 4 | |
95 | ||
96 | - __u32 | |
97 | ||
98 | - ``revision`` | |
99 | ||
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100 | - |
101 | - | |
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102 | - Entity revision. Always zero (obsolete) |
103 | ||
104 | - .. row 5 | |
105 | ||
106 | - __u32 | |
107 | ||
108 | - ``flags`` | |
109 | ||
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110 | - |
111 | - | |
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112 | - Entity flags, see :ref:`media-entity-flag` for details. |
113 | ||
114 | - .. row 6 | |
115 | ||
116 | - __u32 | |
117 | ||
118 | - ``group_id`` | |
119 | ||
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120 | - |
121 | - | |
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122 | - Entity group ID. Always zero (obsolete) |
123 | ||
124 | - .. row 7 | |
125 | ||
126 | - __u16 | |
127 | ||
128 | - ``pads`` | |
129 | ||
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130 | - |
131 | - | |
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132 | - Number of pads |
133 | ||
134 | - .. row 8 | |
135 | ||
136 | - __u16 | |
137 | ||
138 | - ``links`` | |
139 | ||
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140 | - |
141 | - | |
5377d91f | 142 | - Total number of outbound links. Inbound links are not counted in |
0579e6e3 | 143 | this field. |
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144 | |
145 | - .. row 9 | |
146 | ||
147 | - union | |
148 | ||
149 | - .. row 10 | |
150 | ||
0579e6e3 | 151 | - |
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152 | - struct |
153 | ||
154 | - ``dev`` | |
155 | ||
0579e6e3 | 156 | - |
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157 | - Valid for (sub-)devices that create a single device node. |
158 | ||
159 | - .. row 11 | |
160 | ||
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161 | - |
162 | - | |
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163 | - __u32 |
164 | ||
165 | - ``major`` | |
166 | ||
167 | - Device node major number. | |
168 | ||
169 | - .. row 12 | |
170 | ||
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171 | - |
172 | - | |
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173 | - __u32 |
174 | ||
175 | - ``minor`` | |
176 | ||
177 | - Device node minor number. | |
178 | ||
179 | - .. row 13 | |
180 | ||
0579e6e3 | 181 | - |
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182 | - __u8 |
183 | ||
8968da9b | 184 | - ``raw``\ [184] |
5377d91f | 185 | |
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186 | - |
187 | - | |
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188 | |
189 | ||
15e7d615 | 190 | Return Value |
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191 | ============ |
192 | ||
193 | On success 0 is returned, on error -1 and the ``errno`` variable is set | |
194 | appropriately. The generic error codes are described at the | |
195 | :ref:`Generic Error Codes <gen-errors>` chapter. | |
196 | ||
197 | EINVAL | |
e8be7e97 | 198 | The struct :c:type:`media_entity_desc` ``id`` |
5377d91f | 199 | references a non-existing entity. |