Documentation / devicetree / bindings / rtc / rtc-cmos.yaml


Based on kernel version 7.3. Page generated on 2026-10-19 13:17 EDT.

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/rtc/rtc-cmos.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Motorola mc146818 compatible RTC

maintainers:
  - Alexandre Belloni <alexandre.belloni@bootlin.com>

properties:
  compatible:
    oneOf:
      - const: motorola,mc146818

      - items:
          - const: intel,ce4100-rtc
          - const: motorola,mc146818

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

  ctrl-reg:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Initial value of the control register
      (also known as Register B).

  freq-reg:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Initial value of the frequency register
      (also known as Register A).

required:
  - compatible
  - reg

allOf:
  - $ref: rtc.yaml#

unevaluatedProperties: false

examples:
  - |
    bus {
        #address-cells = <2>;
        #size-cells = <1>;
 
        rtc@1,70 {
            compatible = "motorola,mc146818";
            reg = <0x1 0x70 0x2>;
 
            interrupts = <8 3>;
 
            ctrl-reg = <2>;
            freq-reg = <0x26>;
        };
    };