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+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/userspace-api/media/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _media_ioc_enum_entities:
+
+*****************************
+ioctl MEDIA_IOC_ENUM_ENTITIES
+*****************************
+
+Name
+====
+
+MEDIA_IOC_ENUM_ENTITIES - Enumerate entities and their properties
+
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, MEDIA_IOC_ENUM_ENTITIES, struct media_entity_desc *argp )
+    :name: MEDIA_IOC_ENUM_ENTITIES
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <media-func-open>`.
+
+``argp``
+    Pointer to struct :c:type:`media_entity_desc`.
+
+
+Description
+===========
+
+To query the attributes of an entity, applications set the id field of a
+struct :c:type:`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.
+
+
+.. c:type:: media_entity_desc
+
+.. tabularcolumns:: |p{1.5cm}|p{1.7cm}|p{1.6cm}|p{1.5cm}|p{11.2cm}|
+
+.. flat-table:: struct media_entity_desc
+    :header-rows:  0
+    :stub-columns: 0
+    :widths: 2 2 1 8
+
+    *  -  __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. Do not expect that the ID will
+	  always be the same for each instance of the device. In other words,
+	  do not hardcode entity IDs in an application.
+
+    *  -  char
+       -  ``name``\ [32]
+       -
+       -  Entity name as an UTF-8 NULL-terminated string. This name must be unique
+          within the media topology.
+
+    *  -  __u32
+       -  ``type``
+       -
+       -  Entity type, see :ref:`media-entity-functions` for details.
+
+    *  -  __u32
+       -  ``revision``
+       -
+       -  Entity revision. Always zero (obsolete)
+
+    *  -  __u32
+       -  ``flags``
+       -
+       -  Entity flags, see :ref:`media-entity-flag` for details.
+
+    *  -  __u32
+       -  ``group_id``
+       -
+       -  Entity group ID. Always zero (obsolete)
+
+    *  -  __u16
+       -  ``pads``
+       -
+       -  Number of pads
+
+    *  -  __u16
+       -  ``links``
+       -
+       -  Total number of outbound links. Inbound links are not counted in
+	  this field.
+
+    *  -  __u32
+       -  ``reserved[4]``
+       -
+       -  Reserved for future extensions. Drivers and applications must set
+          the array to zero.
+
+    *  -  union {
+       -  (anonymous)
+
+    *  -  struct
+       -  ``dev``
+       -
+       -  Valid for (sub-)devices that create a single device node.
+
+    *  -
+       -  __u32
+       -  ``major``
+       -  Device node major number.
+
+    *  -
+       -  __u32
+       -  ``minor``
+       -  Device node minor number.
+
+    *  -  __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 :c:type:`media_entity_desc` ``id``
+    references a non-existing entity.