The libinput 1.2 release candidate (v1.1.901) features graphics tablet tool support as its primary feature. This tablet tool support includes stylus, eraser, cursor, lens cursor, etc. However, the "pad" part of the tablet tool isn't yet supported.
Libinput 1.2 is also adding three-finger pinch gestures on supported hardware and other improvements.
More details on the tablet work going into libinput 1.2 can be found via today's 1.2 RC release announcement.