gistfile1.py

#!/usr/bin/env python
from evdev import InputDevice, list_devices, ecodes
from os import system

FILTER_ALL = 0x10
FILTER_STYLUS = 0x04

DEFAULT_FILTER = FILTER_ALL

device = None
devices = [InputDevice(fn) for fn in list_devices()]
for dev in devices:
	if dev.phys == "gpio-keys/input0":
		device = dev
		break

penout = 0
lidon = 0

def refresh_filter():
	state = "enable"
	if lidon != 0:
		state = "disable"
	system("xinput " + state + " touch")

	code = DEFAULT_FILTER
	if penout != 0:
		code = FILTER_STYLUS
	with open("/sys/class/misc/touch/report_mode", "w") as f:
		f.write(str(code) + "\n")

sw_events = ecodes.bytype[ecodes.EV_SW]
for event in device.read_loop():
	if event.type == ecodes.EV_SW:
		if sw_events[event.code] == "SW_TABLET_MODE":
			penout = event.value
		elif sw_events[event.code] == "SW_LID":
			lidon = event.value
		refresh_filter()