Re: [PATCH] usb: generic calibration support

[Richard Purdie <rpurdie@rpsys.net>]

On Fri, 2006-11-17 at 15:53 +0100, Holger Schurig wrote:
> > I believe tslib handles this.
> 
> The special X server "KDrive" supports tslib, this is used in 
> many embedded projects, e.g. by images created via 
> http://www.openembedded.org. But mainline X.org server, e.g. 
> what is in Debian unstable (7.1.0), doesn't support tslib.

Someone should add tslib support to the main xorg server then ;-). All
tslib supported devices will then just work...

> Also I don't know if X/tslib allows re-calibration on-the-fly, 
> but I guess it does. 

It does.

> However, tslib usually does not work via 
> the input subsystem (/dev/input/eventX is just one of them), 
> most devices use proprietary kernel interfaces.

tslib does work via the input subsystem for almost every 2.6 kernel
based device I can think of in OpenEmbedded and we made an active effort
to get into that position. The only proprietary interfaces are old 2.4
kernels.

> Qt/Embedded for Qt 2 and Qt 3 doesn't handle tslib 
> out-of-the-box, (heck, the don't even know 
> about /dev/input/eventX), but patches exist.

Qt/E 2/3 have a ton of other input issues beside this (e.e keymap
problems) so the lack of merged tslib support is only a minor one and as
you say, patches exist.

IMO, calibration in the kernel would be a backwards step (especially
when tslib can do more besides like filtering and hopefully in the
future rescaling).

Regards,

Richard