[Xorg] DDC/CI, need advice on implementation

[Nicolas Boichat]

Thanks for the idea, you're probably right.

I have a nVidia card so I'll work on a kernel driver.

Best regards,

Nicolas

Le lun 05/07/2004 à 23:54, Jon Smirl a écrit :
> Does the fbdev driver for your card have a kernel level I2C driver? For
> example matrox and radeon have this already. In that case you can load
> the i2c-dev driver and control the bus from simple user space apps. 
> 
> If not, it might be simpler to implement a kernel I2C driver for your
> card than to mess around with the one in xfree. It is not hard to make
> one, just look at the kernel driver for Matrox (mga) and the xfree
> source code. That will provide everything you need to build your own.
> 
> --- Nicolas Boichat <nicolas at boichat.ch> wrote:
> > Hello
> > 
> > I reverse-engineered a part of the DDC/CI protocol. This protocol is
> > used to control a monitor by software, without using the OSD.
> > 
> > I'll soon write some web pages explaining what I did to
> > reverse-engineer
> > it, and on the protocol itself.
> > 
> > I modified the DDC driver
> > (xc/programs/Xserver/hw/xfree86/ddc/xf86DDC.c), because it is the
> > easiest place to get access to the graphics card I2C bus (DDC2 and
> > DDC/CI are located on the same I2C bus), and I'm now able to read
> > values
> > from my Mitsubishi Diamond Pro 2060u (I mean read contrast,
> > brightness,
> > red, green and blue levels for example), but I still can't write
> > values
> > (I don't think I'm very far).
> > 
> > Now I have a problem, I need to have access to the DDC/CI bus from an
> > external application, because, of course, I don't want to change the
> > monitor parameters only when the server loads.
> > 
> > I don't know much about XFree/Xorg, so I need your help:
> >  - Should I create a new shared library in xc/lib? (for example
> > Xxf86ddcci)
> >  - Or Should I add functions to an existing library ? (in this case,
> > which one? Xxf86vm? Xxf86misc?)
> >  - Or should I do something else??
> > 
> > I would like to add in this library simple wrappers to functions that
> > are in I2C and DDC modules, is it possible and well designed ?
> > 
> > I hope I've been clear enough, if it is not the case please ask me.
> > 
> > Best regards,
> > 
> > Nicolas Boichat
> > 
> > 
> > _______________________________________________
> > xorg mailing list
> > xorg at freedesktop.org
> > http://freedesktop.org/mailman/listinfo/xorg
> > 
> 
> 
> =====
> Jon Smirl
> jonsmirl at yahoo.com
> 
> 
> 		
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