1* GPIO-controlled Watchdog 2 3Required Properties: 4- compatible: Should contain "linux,wdt-gpio". 5- gpios: From common gpio binding; gpio connection to WDT reset pin. 6- hw_algo: The algorithm used by the driver. Should be one of the 7 following values: 8 - toggle: Either a high-to-low or a low-to-high transition clears 9 the WDT counter. The watchdog timer is disabled when GPIO is 10 left floating or connected to a three-state buffer. 11 - level: Low or high level starts counting WDT timeout, 12 the opposite level disables the WDT. Active level is determined 13 by the GPIO flags. 14- hw_margin_ms: Maximum time to reset watchdog circuit (milliseconds). 15 16Optional Properties: 17- always-running: If the watchdog timer cannot be disabled, add this flag to 18 have the driver keep toggling the signal without a client. It will only cease 19 to toggle the signal when the device is open and the timeout elapsed. 20 21Example: 22 watchdog: watchdog { 23 /* ADM706 */ 24 compatible = "linux,wdt-gpio"; 25 gpios = <&gpio3 9 GPIO_ACTIVE_LOW>; 26 hw_algo = "toggle"; 27 hw_margin_ms = <1600>; 28 }; 29