dt-bindings: watchdog: Convert stm32 watchdog bindings to json-schema

STM32 Independent WatchDoG (IWDG)

---------------------------------

Required properties:

- compatible: Should be either:

  - "st,stm32-iwdg"

  - "st,stm32mp1-iwdg"

- reg: Physical base address and length of the registers set for the device

- clocks: Reference to the clock entry lsi. Additional pclk clock entry

  is required only for st,stm32mp1-iwdg.

- clock-names: Name of the clocks used.

  "lsi" for st,stm32-iwdg

  "lsi", "pclk" for st,stm32mp1-iwdg

Optional Properties:

- timeout-sec: Watchdog timeout value in seconds.

Example:

iwdg: watchdog@40003000 {

	compatible = "st,stm32-iwdg";

	reg = <0x40003000 0x400>;

	clocks = <&clk_lsi>;

	clock-names = "lsi";

	timeout-sec = <32>;

};

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/watchdog/st,stm32-iwdg.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: STMicroelectronics STM32 Independent WatchDoG (IWDG) bindings

maintainers:

  - Yannick Fertre <yannick.fertre@st.com>

  - Christophe Roullier <christophe.roullier@st.com>

allOf:

  - $ref: "watchdog.yaml#"

properties:

  compatible:

    enum:

      - st,stm32-iwdg

      - st,stm32mp1-iwdg

  reg:

    maxItems: 1

  clocks:

    items:

      - description: Low speed clock

      - description: Optional peripheral clock

    minItems: 1

    maxItems: 2

  clock-names:

    items:

      enum:

        - lsi

        - pclk

    minItems: 1

    maxItems: 2

required:

  - compatible

  - reg

  - clocks

  - clock-names

examples:

  - |

    #include <dt-bindings/clock/stm32mp1-clks.h>

    watchdog@5a002000 {

      compatible = "st,stm32mp1-iwdg";

      reg = <0x5a002000 0x400>;

      clocks = <&rcc IWDG2>, <&rcc CK_LSI>;

      clock-names = "pclk", "lsi";

      timeout-sec = <32>;

    };

...