Couple minutes ago I finally get the USB HID work ! By changing the USB device name from "Wacom Rip off" to "Wac0m Rip off". I still had no idea why this change make the cursor actually move (as I said earlier that the "evtest" did shows event report). But I suspect that the word "Wacom" is used for driver probing (grep from device name to load driver, Name match ?).

Anyway, There're main 3 problems

1. Y axis is inverted

2. Hovering the pen over the pad does generate event, but cursor doesn't move along unless pen tip is down

3. Sometime Eraser side works with randomly having problem from number 2

The 2 latest commits are on my GitHub repo.