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Diffstat (limited to 'Documentation/DocBook/v4l/media-controller.xml')
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diff --git a/Documentation/DocBook/v4l/media-controller.xml b/Documentation/DocBook/v4l/media-controller.xml index 253ddb4426c..f89228d3ec2 100644 --- a/Documentation/DocBook/v4l/media-controller.xml +++ b/Documentation/DocBook/v4l/media-controller.xml @@ -53,4 +53,24 @@ implementing policies that belong to userspace.</para> <para>The media controller API aims at solving those problems.</para> </section> + + <section id="media-controller-model"> + <title>Media device model</title> + <para>Discovering a device internal topology, and configuring it at runtime, + is one of the goals of the media controller API. To achieve this, hardware + devices are modelled as an oriented graph of building blocks called entities + connected through pads.</para> + <para>An entity is a basic media hardware or software building block. It can + correspond to a large variety of logical blocks such as physical hardware + devices (CMOS sensor for instance), logical hardware devices (a building + block in a System-on-Chip image processing pipeline), DMA channels or + physical connectors.</para> + <para>A pad is a connection endpoint through which an entity can interact + with other entities. Data (not restricted to video) produced by an entity + flows from the entity's output to one or more entity inputs. Pads should not + be confused with physical pins at chip boundaries.</para> + <para>A link is a point-to-point oriented connection between two pads, + either on the same entity or on different entities. Data flows from a source + pad to a sink pad.</para> + </section> </chapter> |