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1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)2%YAML 1.23---4$id: http://devicetree.org/schemas/watchdog/linux,wdt-gpio.yaml#5$schema: http://devicetree.org/meta-schemas/core.yaml#6 7title: GPIO-controlled Watchdog8 9maintainers:10 - Guenter Roeck <linux@roeck-us.net>11 - Robert Marko <robert.marko@sartura.hr>12 13properties:14 compatible:15 const: linux,wdt-gpio16 17 gpios:18 description: gpio connection to WDT reset pin19 maxItems: 120 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 connected27 to a three-state buffer.28 const: toggle29 - description:30 Low or high level starts counting WDT timeout, the opposite level31 disables the WDT.32 Active level is determined by the GPIO flags.33 const: level34 35 hw_margin_ms:36 description: Maximum time to reset watchdog circuit (milliseconds).37 $ref: /schemas/types.yaml#/definitions/uint3238 minimum: 239 maximum: 6553540 41 always-running:42 type: boolean43 description:44 If the watchdog timer cannot be disabled, add this flag to have the driver45 keep toggling the signal without a client.46 It will only cease to toggle the signal when the device is open and the47 timeout elapsed.48 49required:50 - compatible51 - gpios52 - hw_algo53 - hw_margin_ms54 55allOf:56 - $ref: watchdog.yaml#57 58unevaluatedProperties: false59 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