The stylus I'm using operates independently from the capacitive touchscreen and is presented as a separate input device by libinput. The stylus needs external p

The stylus I'm using operates independently from the capacitive touchscreen and is presented as a separate input device by libinput. The stylus needs external power and the input reports not just xy, but z coordinates. Physically I am not sure whats going on, and struggled to find anything authoritative on the subject.