xref: /openbmc/linux/Documentation/devicetree/bindings/watchdog/realtek,otto-wdt.yaml (revision 495cbe36)

# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/watchdog/realtek,otto-wdt.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Realtek Otto watchdog timer

maintainers:
  - Sander Vanheule <sander@svanheule.net>

description: |
  The timer has two timeout phases. Both phases have a maximum duration of 32
  prescaled clock ticks, which is ca. 43s with a bus clock of 200MHz. The
  minimum duration of each phase is one tick. Each phase can trigger an
  interrupt, although the phase 2 interrupt will occur with the system reset.
  - Phase 1: During this phase, the WDT can be pinged to reset the timeout.
  - Phase 2: Starts after phase 1 has timed out, and only serves to give the
    system some time to clean up, or notify others that it's going to reset.
    During this phase, pinging the WDT has no effect, and a reset is
    unavoidable, unless the WDT is disabled.

allOf:
  - $ref: watchdog.yaml#

properties:
  compatible:
    enum:
      - realtek,rtl8380-wdt
      - realtek,rtl8390-wdt
      - realtek,rtl9300-wdt
      - realtek,rtl9310-wdt

  reg:
    maxItems: 1

  clocks:
    maxItems: 1

  interrupts:
    items:
      - description: interrupt specifier for pretimeout
      - description: interrupt specifier for timeout

  interrupt-names:
    items:
      - const: phase1
      - const: phase2

  realtek,reset-mode:
    $ref: /schemas/types.yaml#/definitions/string
    description: |
      Specify how the system is reset after a timeout. Defaults to "cpu" if
      left unspecified.
    oneOf:
      - description: Reset the entire chip
        const: soc
      - description: |
          Reset the CPU and IPsec engine, but leave other peripherals untouched
        const: cpu
      - description: |
          Reset the execution pointer, but don't actually reset any hardware
        const: software

required:
  - compatible
  - reg
  - clocks
  - interrupts
  - interrupt-names

unevaluatedProperties: false

examples:
  - |
    watchdog: watchdog@3150 {
        compatible = "realtek,rtl8380-wdt";
        reg = <0x3150 0xc>;

        realtek,reset-mode = "soc";

        clocks = <&lxbus_clock>;
        timeout-sec = <20>;

        interrupt-parent = <&rtlintc>;
        interrupt-names = "phase1", "phase2";
        interrupts = <19>, <18>;
    };

...