pi_fan_hwpwm.service

[Unit]
Description=Hardware PWM control for Raspberry Pi 4 Case Fan
After=syslog.target

[Service]
Type=simple
User=root
WorkingDirectory=/run
PIDFile=/run/pi_fan_hwpwm.pid
ExecStart=/usr/local/sbin/pi_fan_hwpwm
Restart=on-failure

[Install]
WantedBy=multi-user.target