[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>
This commit is contained in:
parent
fdc40b5e95
commit
b7870d692d
|
@ -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>
|
||||
|
||||
|
|
Loading…
Reference in a new issue