pigrrl-shutdown

#!/usr/bin/env python

# Adafruit PiGRRL PCB alternative configuration
# maps buttons to GPIO for connection to PiTFT
# or mounting back to back to a Raspberry Pi Zero
# soft shutdown is supported through L bumper

import time
import signal
import os
import sys
from datetime import datetime
from threading import Timer

try:
    from evdev import uinput, UInput, ecodes as e
except ImportError:
    exit("This library requires the evdev module\nInstall with: sudo pip install evdev")

try:
    import RPi.GPIO as gpio
except ImportError:
    exit("This library requires the RPi.GPIO module\nInstall with: sudo pip install RPi.GPIO")


#time.sleep(30)

os.system("sudo modprobe uinput")

DEBUG = False

PIDFILE = "/var/run/picadehatd.pid"
LOGFILE = "/var/log/picadehatd.log"

BOUNCE_TIME = 0.01 # Debounce time in seconds
SHUTDOWN_HOLD_TIME = 3 # Time in seconds that power button must be held

SHUTDOWN = 4
BUTTON_POWER = 12

UP = 16
DOWN = 26
LEFT = 4
RIGHT = 19

BUTTON1 = 14
BUTTON2 = 15
BUTTON3 = 20
BUTTON4 = 18

ENTER = 5
START= 6

BUTTONS = [ENTER,START,BUTTON1,BUTTON2,BUTTON3,BUTTON4,UP,DOWN,LEFT,RIGHT]

KEYS = {
    ENTER: e.KEY_ENTER,
    START: e.KEY_S,
    UP: e.KEY_UP,
    DOWN: e.KEY_DOWN,
    LEFT: e.KEY_LEFT,
    RIGHT: e.KEY_RIGHT,
    BUTTON1: e.KEY_LEFTCTRL,
    BUTTON2: e.KEY_LEFTALT,
    BUTTON3: e.KEY_SPACE,
    BUTTON4: e.KEY_LEFTSHIFT,
}

states = [False for b in BUTTONS]

shutdown_timer = None

try:
    pid = os.fork()
    if pid > 0:
        sys.exit(0)

except OSError, e:
    print("Fork #1 failed: {} ({})".format(e.errno, e.strerror))
    sys.exit(1)

os.chdir("/")
os.setsid()
os.umask(0)

try:
    pid = os.fork()
    if pid > 0:
        fpid = open(PIDFILE, 'w')
        fpid.write(str(pid))
        fpid.close()
        sys.exit(0)
except OSError, e:
    print("Fork #2 failed: {} ({})".format(e.errno, e.strerror))
    sys.exit(1)

si = file("/dev/null", 'r')
so = file(LOGFILE, 'a+')
se = file("/dev/null", 'a+', 0)

os.dup2(si.fileno(), sys.stdin.fileno())
os.dup2(so.fileno(), sys.stdout.fileno())
os.dup2(se.fileno(), sys.stderr.fileno())

gpio.setmode(gpio.BCM)
gpio.setwarnings(False)
gpio.setup(BUTTONS, gpio.IN, pull_up_down=gpio.PUD_UP)
gpio.setup(BUTTON_POWER, gpio.IN, pull_up_down=gpio.PUD_UP)

try:
    ui = UInput({e.EV_KEY: KEYS.values()}, name="PiGRRL-PCB", bustype=e.BUS_USB)

except uinput.UInputError as e:
    sys.stdout.write(e.message)
    sys.stdout.write("Have you tried running as root? sudo {}".format(sys.argv[0]))
    sys.exit(0)

def log(msg):
    sys.stdout.write(str(datetime.now()))
    sys.stdout.write(": ")
    sys.stdout.write(msg)
    sys.stdout.write("\n")
    sys.stdout.flush()

def handle_button(pin):
    key = KEYS[pin]
    time.sleep(BOUNCE_TIME)
    state = 0 if gpio.input(pin) else 1
    ui.write(e.EV_KEY, key, state)
    ui.syn()
    if DEBUG:
        log("Pin: {}, KeyCode: {}, Event: {}".format(pin, key, 'press' if state else 'release'))

def perform_shutdown():
    log("Shutting down...")
    os.system("sudo shutdown -h now")

def handle_shutdown(pin):
    global shutdown_timer

    time.sleep(BOUNCE_TIME)
    state = 0 if gpio.input(pin) else 1

    if DEBUG:
        log("Power button: {}".format('pressed' if state else 'released'))

    if state and shutdown_timer is None:
        shutdown_timer = Timer(SHUTDOWN_HOLD_TIME, perform_shutdown)
        shutdown_timer.start()

    elif not state and shutdown_timer is not None:
        shutdown_timer.cancel()
        shutdown_timer = None

for button in BUTTONS:
    gpio.add_event_detect(button, gpio.BOTH, callback=handle_button, bouncetime=1)

gpio.add_event_detect(BUTTON_POWER, gpio.BOTH, callback=handle_shutdown, bouncetime=1)

log("Picade HAT daemon running...")

try:
    signal.pause()
except KeyboardInterrupt:
    pass

log("daemon shutting down...")

ui.close()