mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-26 19:00:25 +00:00
Code Issues Releases Wiki Activity

[media] DocBook: MC: add the concept of interfaces

Browse source 
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:
Mauro Carvalho Chehab 2015-12-12 08:59:14 -02:00
parent fdc40b5e95
commit b7870d692d
1 changed files with 26 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

40
Documentation/DocBook/media/v4l/media-controller.xml
View file

@ -58,20 +58,32 @@
<title>Media device model</title> <title>Media device model</title>
<para>Discovering a device internal topology, and configuring it at runtime, <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 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 devices and Linux Kernel interfaces are modelled as graph objects on
connected through pads.</para> an oriented graph. The object types that constitute the graph are:</para>
<para>An entity is a basic media hardware or software building block. It can <itemizedlist>
correspond to a large variety of logical blocks such as physical hardware <listitem><para>An <emphasis role="bold">entity</emphasis>
devices (CMOS sensor for instance), logical hardware devices (a building is a basic media hardware or software building block. It can correspond to
block in a System-on-Chip image processing pipeline), DMA channels or a large variety of logical blocks such as physical hardware devices
physical connectors.</para> (CMOS sensor for instance), logical hardware devices (a building block in
<para>A pad is a connection endpoint through which an entity can interact a System-on-Chip image processing pipeline), DMA channels or physical
with other entities. Data (not restricted to video) produced by an entity connectors.</para></listitem>
flows from the entity's output to one or more entity inputs. Pads should not <listitem><para>An <emphasis role="bold">interface</emphasis>
be confused with physical pins at chip boundaries.</para> is a graph representation of a Linux Kernel userspace API interface,
<para>A link is a point-to-point oriented connection between two pads, like a device node or a sysfs file that controls one or more entities
either on the same entity or on different entities. Data flows from a source in the graph.</para></listitem>
pad to a sink pad.</para> <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> </section>
</chapter> </chapter>