atmel,at91sam9-wdt.yaml

  1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
  2# Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
  3%YAML 1.2
  4---
  5$id: http://devicetree.org/schemas/watchdog/atmel,at91sam9-wdt.yaml#
  6$schema: http://devicetree.org/meta-schemas/core.yaml#
  7
  8title: Atmel Watchdog Timers
  9
 10maintainers:
 11  - Eugen Hristev <eugen.hristev@microchip.com>
 12
 13properties:
 14  compatible:
 15    const: atmel,at91sam9260-wdt
 16
 17  reg:
 18    maxItems: 1
 19
 20  clocks:
 21    maxItems: 1
 22
 23  interrupts:
 24    maxItems: 1
 25
 26  atmel,max-heartbeat-sec:
 27    description:
 28      Should contain the maximum heartbeat value in seconds. This value
 29      should be less or equal to 16. It is used to compute the WDV field.
 30    maximum: 16
 31
 32  atmel,min-heartbeat-sec:
 33    description:
 34      Should contain the minimum heartbeat value in seconds. This value
 35      must be smaller than the max-heartbeat-sec value. It is used to
 36      compute the WDD field.
 37    maximum: 16
 38
 39  atmel,watchdog-type:
 40    $ref: /schemas/types.yaml#/definitions/string
 41    description: |
 42      Should be hardware or software.
 43    oneOf:
 44      - description:
 45          Hardware watchdog uses the at91 watchdog reset.
 46        const: hardware
 47      - description: |
 48          Software watchdog uses the watchdog interrupt
 49          to trigger a software reset.
 50        const: software
 51    default: hardware
 52
 53  atmel,reset-type:
 54    $ref: /schemas/types.yaml#/definitions/string
 55    description: |
 56      Should be proc or all. This is valid only when using hardware watchdog.
 57    oneOf:
 58      - description:
 59          Assert peripherals and processor reset signals.
 60        const: all
 61      - description:
 62          Assert the processor reset signal.
 63        const: proc
 64    default: all
 65
 66  atmel,disable:
 67    $ref: /schemas/types.yaml#/definitions/flag
 68    description:
 69      Should be present if you want to stop the watchdog.
 70
 71  atmel,idle-halt:
 72    $ref: /schemas/types.yaml#/definitions/flag
 73    description: |
 74      Should be present if you want to stop the watchdog when
 75      entering idle state.
 76      CAUTION: This property should be used with care, it actually makes the
 77      watchdog not counting when the CPU is in idle state, therefore the
 78      watchdog reset time depends on mean CPU usage and will not reset at all
 79      if the CPU stops working while it is in idle state, which is probably
 80      not what you want.
 81
 82  atmel,dbg-halt:
 83    $ref: /schemas/types.yaml#/definitions/flag
 84    description: |
 85      Should be present if you want to stop the watchdog when
 86      entering debug state.
 87
 88required:
 89  - compatible
 90  - reg
 91  - clocks
 92
 93allOf:
 94  - $ref: watchdog.yaml#
 95  - if:
 96      properties:
 97        atmel,reset-type:
 98          enum:
 99            - all
100            - proc
101    then:
102      properties:
103        atmel,watchdog-type:
104          const: hardware
105
106dependencies:
107  atmel,reset-type: ['atmel,watchdog-type']
108
109unevaluatedProperties: false
110
111examples:
112  - |
113    #include <dt-bindings/interrupt-controller/irq.h>
114
115    watchdog@fffffd40 {
116        compatible = "atmel,at91sam9260-wdt";
117        reg = <0xfffffd40 0x10>;
118        interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
119        clocks = <&clk32k>;
120        timeout-sec = <15>;
121        atmel,watchdog-type = "hardware";
122        atmel,reset-type = "all";
123        atmel,dbg-halt;
124        atmel,idle-halt;
125        atmel,max-heartbeat-sec = <16>;
126        atmel,min-heartbeat-sec = <0>;
127    };