https://www.waveshare.com/rtc-watchdog-hat.htm
watchdog-device = /dev/watchdog1
interval = 30
/dts-v1/;
/plugin/;
/ {
compatible = "brcm,bcm2708";
fragment@0 {
target = <&soc>;
__overlay__ {
gpio_watchdog {
compatible = "linux,wdt-gpio";
gpios = <&gpio 4 0>;
hw_algo = "toggle";
hw_margin_ms = <1000>;
};
};
};
};
dtc -@ -I dts -O dtb -o max705-wdt.dtbo max705-wdt.dts
cp max-705-wdt.dtbo /boot/overlays/