Files
agnos-builder/userspace/usr/comma/power_drop_monitor.py
T
2023-04-24 14:15:35 -07:00

131 lines
3.7 KiB
Python
Executable File

#!/usr/bin/env python
import os
import time
import smbus2
import select
import datetime
import subprocess
ALERT_VOLTAGE_THRESHOLD_mV = 4000
POWER_ALERT_GPIO_PIN = 1264
INA231_BUS = 0
INA231_ADDRESS = 0x40
INA231_MASK_REG = 0x06
INA231_LIMIT_REG = 0x07
INA231_MASK_CONFIG = (1 << 12) # Bus undervoltage, not latching
INA231_BUS_VOLTAGE_LSB_mV = 1.25
VOLTAGE_FILE = "/sys/class/hwmon/hwmon1/in1_input"
PARAM_FILE = "/data/params/d/LastPowerDropDetected"
alert_pin_base = f"/sys/class/gpio/gpio{POWER_ALERT_GPIO_PIN}/"
def set_screen_power(on):
with open("/sys/class/backlight/panel0-backlight/bl_power", "w") as f:
f.write("0\n" if on else "4\n")
def get_screen_power():
with open("/sys/class/backlight/panel0-backlight/bl_power", "r") as f:
return f.read(1) == "0"
def swap_word_bytes(val):
return ((val & 0xFF) << 8) | ((val & 0xFF00) >> 8)
def write_once(path, value):
with open(path, 'w') as f:
f.write(value)
def init_alert_pin():
write_once(os.path.join(alert_pin_base, 'direction'), 'in')
write_once(os.path.join(alert_pin_base, 'edge'), 'falling')
def init_voltage_alert():
with smbus2.SMBus(INA231_BUS) as bus:
bus.write_word_data(INA231_ADDRESS, INA231_MASK_REG, swap_word_bytes(INA231_MASK_CONFIG), force=True)
bus.write_word_data(INA231_ADDRESS, INA231_LIMIT_REG, swap_word_bytes(int(ALERT_VOLTAGE_THRESHOLD_mV / INA231_BUS_VOLTAGE_LSB_mV)), force=True)
def read_voltage_mV():
with open(VOLTAGE_FILE, "r") as f:
return int(f.read().strip())
def read_current_mA():
with open("/sys/class/hwmon/hwmon1/curr1_input", "r") as f:
return int(f.read().strip())
def update_param(stage, v_initial, i_initial, v_final, i_final):
try:
os.umask(0)
with open(os.open(PARAM_FILE, os.O_CREAT | os.O_WRONLY, 0o777), 'a') as f:
f.write(f"{stage} {datetime.datetime.now()}, ({v_initial=} mV, {i_initial=} mA) -> ({v_final=} mV, {i_final=} mA)\n")
f.flush()
os.fdatasync(f.fileno())
os.fsync(f.fileno())
except Exception:
print("Failed to update LastControlledShutdown param")
def printk(msg):
with open('/dev/kmsg', 'w') as kmsg:
kmsg.write(f"<3>[power drop monitor] {msg}\n")
print(msg)
def perform_controlled_shutdown():
printk("Power alert received!")
prev_screen_power = get_screen_power()
set_screen_power(False)
v_initial = read_voltage_mV()
i_initial = read_current_mA()
update_param("PREP", v_initial, i_initial, None, None)
# Wait 100ms before checking voltage level again
t = time.monotonic()
while time.monotonic() - t < 0.1:
time.sleep(0.01)
v_now = read_voltage_mV()
i_now = read_current_mA()
if v_now > ALERT_VOLTAGE_THRESHOLD_mV:
printk("Voltage restored. Not shutting down!")
update_param("ABORT", v_initial, i_initial, v_now, i_now)
set_screen_power(prev_screen_power)
return
update_param("SHUTDOWN", v_initial, i_initial, v_now, i_now)
# TODO: let loggerd cleanly finish writing logs
printk("Unmount NVMe")
subprocess.call(["/usr/bin/umount", "-l", "/dev/nvme0"])
# TODO: turn off nvme regulator. Currently no userspace control over this
# Kill services that draw a lot of power
printk("Killing services")
subprocess.call(["/usr/bin/systemctl", "kill", "--signal=9", "weston", "comma"])
set_screen_power(False)
printk("Halt")
subprocess.call(["/usr/sbin/halt", "-f"])
if __name__ == '__main__':
init_alert_pin()
init_voltage_alert()
# Setup interrupt
f = open(os.path.join(alert_pin_base, 'value'), 'r')
po = select.poll()
po.register(f, select.POLLPRI)
# Interrupt loop
f.read()
while True:
try:
events = po.poll(60000)
if events:
f.seek(0)
state_last = f.read().strip()
if int(state_last) == 0:
perform_controlled_shutdown()
except Exception:
pass