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