1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2%YAML 1.2 3--- 4$id: http://devicetree.org/schemas/watchdog/linux,wdt-gpio.yaml# 5$schema: http://devicetree.org/meta-schemas/core.yaml# 6 7title: GPIO-controlled Watchdog 8 9maintainers: 10 - Guenter Roeck <linux@roeck-us.net> 11 - Robert Marko <robert.marko@sartura.hr> 12 13properties: 14 compatible: 15 const: linux,wdt-gpio 16 17 gpios: 18 description: gpio connection to WDT reset pin 19 maxItems: 1 20 21 hw_algo: 22 description: The algorithm used by the driver. 23 oneOf: 24 - description: 25 Either a high-to-low or a low-to-high transition clears the WDT counter. 26 The watchdog timer is disabled when GPIO is left floating or connected 27 to a three-state buffer. 28 const: toggle 29 - description: 30 Low or high level starts counting WDT timeout, the opposite level 31 disables the WDT. 32 Active level is determined by the GPIO flags. 33 const: level 34 35 hw_margin_ms: 36 description: Maximum time to reset watchdog circuit (milliseconds). 37 $ref: /schemas/types.yaml#/definitions/uint32 38 minimum: 2 39 maximum: 65535 40 41 always-running: 42 type: boolean 43 description: 44 If the watchdog timer cannot be disabled, add this flag to have the driver 45 keep toggling the signal without a client. 46 It will only cease to toggle the signal when the device is open and the 47 timeout elapsed. 48 49required: 50 - compatible 51 - gpios 52 - hw_algo 53 - hw_margin_ms 54 55allOf: 56 - $ref: watchdog.yaml# 57 58unevaluatedProperties: false 59 60examples: 61 - | 62 #include <dt-bindings/gpio/gpio.h> 63 watchdog { 64 compatible = "linux,wdt-gpio"; 65 gpios = <&gpio3 9 GPIO_ACTIVE_LOW>; 66 hw_algo = "toggle"; 67 hw_margin_ms = <1600>; 68 }; 69