Bindings/rtc/st,stm32-rtc.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/rtc/st,stm32-rtc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: STMicroelectronics STM32 Real Time Clock

maintainers:
  - Gabriel Fernandez <gabriel.fernandez@foss.st.com>

properties:
  compatible:
    enum:
      - st,stm32-rtc
      - st,stm32h7-rtc
      - st,stm32mp1-rtc
      - st,stm32mp25-rtc

  reg:
    maxItems: 1

  clocks:
    minItems: 1
    maxItems: 2

  clock-names:
    items:
      - const: pclk
      - const: rtc_ck

  interrupts:
    maxItems: 1

  st,syscfg:
    $ref: /schemas/types.yaml#/definitions/phandle-array
    items:
      minItems: 3
      maxItems: 3
    description: |
      Phandle/offset/mask triplet. The phandle to pwrcfg used to
      access control register at offset, and change the dbp (Disable Backup
      Protection) bit represented by the mask, mandatory to disable/enable backup
      domain (RTC registers) write protection.

  assigned-clocks:
    description: |
      override default rtc_ck parent clock reference to the rtc_ck clock entry
    maxItems: 1

  assigned-clock-parents:
    description: |
      override default rtc_ck parent clock phandle of the new parent clock of rtc_ck
    maxItems: 1

patternProperties:
  "^rtc-[a-z]+-[0-9]+$":
    type: object
    $ref: /schemas/pinctrl/pinmux-node.yaml
    description: |
      Configuration of STM32 RTC pins description. STM32 RTC is able to output
      some signals on specific pins:
      - LSCO (Low Speed Clock Output) that allow to output LSE clock on a pin.
      - Alarm out that allow to send a pulse on a pin when alarm A of the RTC
        expires.
    additionalProperties: false
    properties:
      function:
        enum:
          - lsco
          - alarm-a
      pins:
        enum:
          - out1
          - out2
          - out2_rmp

allOf:
  - if:
      properties:
        compatible:
          contains:
            const: st,stm32-rtc

    then:
      properties:
        clocks:
          minItems: 1
          maxItems: 1

        clock-names: false

      patternProperties:
        "^rtc-[a-z]+-[0-9]+$": false

      required:
        - st,syscfg

  - if:
      properties:
        compatible:
          contains:
            const: st,stm32h7-rtc

    then:
      properties:
        clocks:
          minItems: 2
          maxItems: 2

      patternProperties:
        "^rtc-[a-z]+-[0-9]+$": false

      required:
        - clock-names
        - st,syscfg

  - if:
      properties:
        compatible:
          contains:
            enum:
              - st,stm32mp1-rtc
              - st,stm32mp25-rtc

    then:
      properties:
        clocks:
          minItems: 2
          maxItems: 2

        assigned-clocks: false
        assigned-clock-parents: false

      required:
        - clock-names

required:
  - compatible
  - reg
  - clocks
  - interrupts

additionalProperties: false

examples:
  - |
    #include <dt-bindings/mfd/stm32f4-rcc.h>
    #include <dt-bindings/clock/stm32fx-clock.h>
    rtc@40002800 {
      compatible = "st,stm32-rtc";
      reg = <0x40002800 0x400>;
      clocks = <&rcc 1 CLK_RTC>;
      assigned-clocks = <&rcc 1 CLK_RTC>;
      assigned-clock-parents = <&rcc 1 CLK_LSE>;
      interrupt-parent = <&exti>;
      interrupts = <17 1>;
      st,syscfg = <&pwrcfg 0x00 0x100>;
    };

  - |
    #include <dt-bindings/interrupt-controller/arm-gic.h>
    #include <dt-bindings/clock/stm32mp1-clks.h>
    rtc@5c004000 {
      compatible = "st,stm32mp1-rtc";
      reg = <0x5c004000 0x400>;
      clocks = <&rcc RTCAPB>, <&rcc RTC>;
      clock-names = "pclk", "rtc_ck";
      interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
    };

...