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| author | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-12-12 08:59:14 -0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2016-01-11 12:19:11 -0200 |
| commit | b7870d692d7b0718f7153aed9e7a32f0119b525d (patch) | |
| tree | eefa33cda39f1c900b445a98c49942e07a896282 | |
| parent | fdc40b5e95ac6480f6160081774aa2ec24784ccb (diff) | |
| download | lwn-b7870d692d7b0718f7153aed9e7a32f0119b525d.tar.gz lwn-b7870d692d7b0718f7153aed9e7a32f0119b525d.zip | |
[media] DocBook: MC: add the concept of interfaces
The Media Controller next generation patches added a new graph
element type: interfaces. It also allows links between interfaces
and entities. Update the docbook to reflect that.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
| -rw-r--r-- | Documentation/DocBook/media/v4l/media-controller.xml | 40 |
1 files changed, 26 insertions, 14 deletions
diff --git a/Documentation/DocBook/media/v4l/media-controller.xml b/Documentation/DocBook/media/v4l/media-controller.xml index 873ac3a621f0..def4a27aadef 100644 --- a/Documentation/DocBook/media/v4l/media-controller.xml +++ b/Documentation/DocBook/media/v4l/media-controller.xml @@ -58,20 +58,32 @@ <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> + devices and Linux Kernel interfaces are modelled as graph objects on + an oriented graph. The object types that constitute the graph are:</para> + <itemizedlist> + <listitem><para>An <emphasis role="bold">entity</emphasis> + 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></listitem> + <listitem><para>An <emphasis role="bold">interface</emphasis> + is a graph representation of a Linux Kernel userspace API interface, + like a device node or a sysfs file that controls one or more entities + in the graph.</para></listitem> + <listitem><para>A <emphasis role="bold">pad</emphasis> + is a data 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></listitem> + <listitem><para>A <emphasis role="bold">data link</emphasis> + 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></listitem> + <listitem><para>An <emphasis role="bold">interface link</emphasis> + is a point-to-point bidirectional control connection between a Linux + Kernel interface and an entity.m</para></listitem> + </itemizedlist> </section> </chapter> |