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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
%YAML 1.2
---
$id: http://devicetree.org/schemas/watchdog/atmel,at91sam9-wdt.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Atmel Watchdog Timers
maintainers:
- Eugen Hristev <eugen.hristev@microchip.com>
properties:
compatible:
const: atmel,at91sam9260-wdt
reg:
maxItems: 1
clocks:
maxItems: 1
interrupts:
maxItems: 1
atmel,max-heartbeat-sec:
description:
Should contain the maximum heartbeat value in seconds. This value
should be less or equal to 16. It is used to compute the WDV field.
maximum: 16
atmel,min-heartbeat-sec:
description:
Should contain the minimum heartbeat value in seconds. This value
must be smaller than the max-heartbeat-sec value. It is used to
compute the WDD field.
maximum: 16
atmel,watchdog-type:
$ref: /schemas/types.yaml#/definitions/string
description: |
Should be hardware or software.
oneOf:
- description:
Hardware watchdog uses the at91 watchdog reset.
const: hardware
- description: |
Software watchdog uses the watchdog interrupt
to trigger a software reset.
const: software
default: hardware
atmel,reset-type:
$ref: /schemas/types.yaml#/definitions/string
description: |
Should be proc or all. This is valid only when using hardware watchdog.
oneOf:
- description:
Assert peripherals and processor reset signals.
const: all
- description:
Assert the processor reset signal.
const: proc
default: all
atmel,disable:
$ref: /schemas/types.yaml#/definitions/flag
description:
Should be present if you want to stop the watchdog.
atmel,idle-halt:
$ref: /schemas/types.yaml#/definitions/flag
description: |
Should be present if you want to stop the watchdog when
entering idle state.
CAUTION: This property should be used with care, it actually makes the
watchdog not counting when the CPU is in idle state, therefore the
watchdog reset time depends on mean CPU usage and will not reset at all
if the CPU stops working while it is in idle state, which is probably
not what you want.
atmel,dbg-halt:
$ref: /schemas/types.yaml#/definitions/flag
description: |
Should be present if you want to stop the watchdog when
entering debug state.
required:
- compatible
- reg
- clocks
allOf:
- $ref: watchdog.yaml#
- if:
properties:
atmel,reset-type:
enum:
- all
- proc
then:
properties:
atmel,watchdog-type:
const: hardware
dependencies:
atmel,reset-type: ['atmel,watchdog-type']
unevaluatedProperties: false
examples:
- |
#include <dt-bindings/interrupt-controller/irq.h>
watchdog@fffffd40 {
compatible = "atmel,at91sam9260-wdt";
reg = <0xfffffd40 0x10>;
interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
clocks = <&clk32k>;
timeout-sec = <15>;
atmel,watchdog-type = "hardware";
atmel,reset-type = "all";
atmel,dbg-halt;
atmel,idle-halt;
atmel,max-heartbeat-sec = <16>;
atmel,min-heartbeat-sec = <0>;
};