Hi,
  Currently, the 'usbtouchscreen' module sends raw data from the
touchscreen directly to the user. However, in general, touchscreens
need to be calibrated, and the raw data needs to be transformed
according to the calibration, before the data can be used as an input
device. Currently, some special purpose drivers exists for this in X,
but the situation is a bit messy. I propose to add support for
calibration parameters in the kernel. That way, we can also get usable
touchscreens without X, without having to write special purpose
drivers to handle the data from the touchscreen. The attached patch
adds support for this. A module parameter (transform_xy)
enables/disables this behavior, so the patch is not very intrusive,
and should cause issues to current users.

Comments would be appricated,
S=F8ren

P.S. I'm not subscribed to the list so please keep me in the CC.