[Q] Software control of LCD backlight?

[Alex Deucher]

On 8/10/07, Hal V. Engel <hvengel at astound.net> wrote:
> On Friday 10 August 2007 14:31, Xavier Bestel wrote:
> > Le vendredi 10 août 2007 à 15:30 -0400, Alex Deucher a écrit :
> > > I don't know anything much about the ddc/ci spec, but it would be
> > > pretty easy to expose the i2c interface for each output in randr.
> > > What's we'd do wtih that interface depends on what's needed for
> > > ddc/ci.
> >
> > Then ddccontrol has lots of interesting code, and a pretty monitor
> > database in xml format (all monitors inheriting from the VESA settings),
> > but once again this code is GPL.
> >
> >       Xav
>
> At one time the main ddccontrol developers were looking for a way to
> incorporate thier code base into a larger project.  They contacted the
> lm-sensors project about this.  Other than lm-sensors also using the i2c
> interface it was not a good fit and the lm-sensors project was not
> interested.     On the other hand the functionality in the ddccontrol library
> is a good fit for X.Org and I am perplexed that they didn't make a similar
> proposal to X.Org at that time.   There are only 6 developers on the project
> and so it seems to me that it might be possible to convice them to relicense
> the library code (the project has a library, a command line front end and a
> GTK front end) to something that works for X.Org as a prelude to migrating
> the library functionality to be a standard X.Org library.  Just a thought.
>
> On the other hand looking at the code base it looks like most of the code in
> the library is there to deal with i2c interfacing so it may not be too big of
> a deal to just start from scratch if the randr folks intend to expose the i2c
> interface anyway.

On the xorg side, we could just release a lib the exposes the xserver
i2c interface.  the randr could just expose i2c bus pointers from the
outputs.  any app that wanted access to the i2c buses could use the
lib to do stuff (dump edid, do ddc/ci, etc.).  if we ever add a GPU
level randr, we could also expose non-output related i2c buses for
multi-media and whatnot.

Alex