(Arnd: sorry for not cc-ing you on v5 of our with Sylwester V4L2 DT RFC. An archive link is below, I'm also CCing ALKML in this mail, as you requested. You might actually also have the RFC in your mail archives from the devicetree-discuss list)
On Wed, 5 Sep 2012, Mauro Carvalho Chehab wrote:
Em 05-09-2012 08:50, Guennadi Liakhovetski escreveu:
On Mon, 3 Sep 2012, Hans Verkuil wrote:
On Mon September 3 2012 19:32:22 Mauro Carvalho Chehab wrote:
[snip]
While not officially at the workshop's agenda, it would be valuable if you could add the DT x V4L2 notes also there (sorry, at the end, I couldn't went there - got busy with some other unrelated stuff).
It would be best if Guennadi would do that: I was too unfamiliar with DT to give a good report of that meeting. Guennadi made some notes of the meeting as well.
Is this my recent post of v5 of the RFC
http://www.mail-archive.com/linux-media@vger.kernel.org/msg51420.html
sufficient or would you like me to prepare a text, suitable for direct inclusion in the workshop notes?
It would be nice to have a text for inclusion at workshop notes. It can point to the RFC proposal in order to provide more details.
How about this:
An RFC to add Device Tree bindings to the V4L2 subsystem has been discussed. Version 4 of that RFC has been developed jointly by Sylwester Nawrocki and Guennadi Liakhovetski and posted to the linux-media mailing list shortly before the conference. Both V4L2 developers and developers from other areas of the kernel with rich experience in designing device-tree bindings took part in the discussion and provided their valuable comments.
The high-level design of the V4L2 DT implementation defines DT nodes of multiple types: camera sensors, TV decoders and encoders and similar devices, typically controlled over I2C or a similar bus, should also reside on their respective (control) busses. Video bridge engines and other data processing units, typically implemented in respective SoCs, are also each represented by a separate DT node. An important part of the media hardware representation is a description of data links between all the above parts, especially between the SoCs and external components. Such links are represented by child nodes of both receiver and transmitter DT nodes.
During the conference the general concept has been approved. Multiple improvement suggestions have been provided for clock bindings within media DT nodes, property naming, location of the bus-width property and similar properties, describing the data bus topology. An important amendment to the RFC is the addition of a "port" DT node level. Now the afore mentioned link sub-nodes should be placed under these port nodes.
As a result of the discussion, version 5 of the RFC has been designed and posted: http://www.mail-archive.com/linux-media@vger.kernel.org/msg51420.html After further cosmetic improvements it should lead to a proper patch, adding V4L2 DT bindings to the kernel documentation and their implementation in the media drivers.
Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/