Re: Replacement for tslib?

Enrico Scholz
2016-08-31T23:54:05Z

Richard Purdie <richard.purdie@linuxfoundation.org> writes:

>> tslib is more or less mandatory for resistive touchscreens but it was
>> removed some days ago. This breaks e.g. meta-qt5 layer which depends
>> on it.
>>
>> Is this removal really final (which would be really bad, because
>> resistive touchscreens are used e.g. in industrial environments)?
> [...]
> Are you sure the kernel interfaces that xinput is using don't work for
> qt4/qt5?

I am not aware of any way how /dev/input/eventX values can be calibrated
within the kernel.

Most capacitive touchscreens are doing this calibration in hardware
so that values correspond 1:1 to screen coordinates. But resistive
touchscreens return usually only the raw 10-12 bit ADC values in
ABS_X/Y.

Enrico