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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _media_ioc_enum_entities:
+
+*****************************
+ioctl MEDIA_IOC_ENUM_ENTITIES
+*****************************
+
+Name
+====
+
+MEDIA_IOC_ENUM_ENTITIES - Enumerate entities and their properties
+
+
+Synopsis
+========
+
+.. cpp:function:: int ioctl( int fd, int request, struct media_entity_desc *argp )
+
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :ref:`open() <media-func-open>`.
+
+``request``
+ MEDIA_IOC_ENUM_ENTITIES
+
+``argp``
+
+
+Description
+===========
+
+To query the attributes of an entity, applications set the id field of a
+struct :ref:`media_entity_desc <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 error code when the id is invalid.
+
+.. _media-ent-id-flag-next:
+
+Entities can be enumerated by or'ing the id with the
+``MEDIA_ENT_ID_FLAG_NEXT`` flag. The driver will return information
+about the entity with the smallest id strictly larger than the requested
+one ('next entity'), or the ``EINVAL`` error code if there is none.
+
+Entity IDs can be non-contiguous. Applications must *not* try to
+enumerate entities by calling MEDIA_IOC_ENUM_ENTITIES with increasing
+id's until they get an error.
+
+
+.. _media-entity-desc:
+
+.. flat-table:: struct media_entity_desc
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 1 1 8
+
+
+ - .. row 1
+
+ - __u32
+
+ - ``id``
+
+ -
+ -
+ - Entity id, set by the application. When the id is or'ed with
+ ``MEDIA_ENT_ID_FLAG_NEXT``, the driver clears the flag and returns
+ the first entity with a larger id.
+
+ - .. row 2
+
+ - char
+
+ - ``name``\ [32]
+
+ -
+ -
+ - Entity name as an UTF-8 NULL-terminated string.
+
+ - .. row 3
+
+ - __u32
+
+ - ``type``
+
+ -
+ -
+ - Entity type, see :ref:`media-entity-type` for details.
+
+ - .. row 4
+
+ - __u32
+
+ - ``revision``
+
+ -
+ -
+ - Entity revision. Always zero (obsolete)
+
+ - .. row 5
+
+ - __u32
+
+ - ``flags``
+
+ -
+ -
+ - Entity flags, see :ref:`media-entity-flag` for details.
+
+ - .. row 6
+
+ - __u32
+
+ - ``group_id``
+
+ -
+ -
+ - Entity group ID. Always zero (obsolete)
+
+ - .. row 7
+
+ - __u16
+
+ - ``pads``
+
+ -
+ -
+ - Number of pads
+
+ - .. row 8
+
+ - __u16
+
+ - ``links``
+
+ -
+ -
+ - Total number of outbound links. Inbound links are not counted in
+ this field.
+
+ - .. row 9
+
+ - union
+
+ - .. row 10
+
+ -
+ - struct
+
+ - ``dev``
+
+ -
+ - Valid for (sub-)devices that create a single device node.
+
+ - .. row 11
+
+ -
+ -
+ - __u32
+
+ - ``major``
+
+ - Device node major number.
+
+ - .. row 12
+
+ -
+ -
+ - __u32
+
+ - ``minor``
+
+ - Device node minor number.
+
+ - .. row 13
+
+ -
+ - __u8
+
+ - ``raw``\ [184]
+
+ -
+ -
+
+
+Return Value
+============
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.
+
+EINVAL
+ The struct :ref:`media_entity_desc <media-entity-desc>` ``id``
+ references a non-existing entity.