dt-bindings: rng: timeriomem_rng: convert TimerIO RNG to dtschema

HWRNG support for the timeriomem_rng driver

Required properties:

- compatible : "timeriomem_rng"

- reg : base address to sample from

- period : wait time in microseconds to use between samples

Optional properties:

- quality : estimated number of bits of true entropy per 1024 bits read from the

            rng.  Defaults to zero which causes the kernel's default quality to

            be used instead.  Note that the default quality is usually zero

            which disables using this rng to automatically fill the kernel's

            entropy pool.

N.B. currently 'reg' must be at least four bytes wide and 32-bit aligned

Example:

hwrng@44 {

	#address-cells = <1>;

	#size-cells = <1>;

	compatible = "timeriomem_rng";

	reg = <0x44 0x04>;

	period = <1000000>;

};

# SPDX-License-Identifier: GPL-2.0-only

%YAML 1.2

---

$id: http://devicetree.org/schemas/rng/timeriomem_rng.yaml#

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

title: TimerIO Random Number Generator

maintainers:

  - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

properties:

  compatible:

    const: timeriomem_rng

  period:

    $ref: /schemas/types.yaml#/definitions/uint32

    description: wait time in microseconds to use between samples

  quality:

    $ref: /schemas/types.yaml#/definitions/uint32

    default: 0

    description:

      Estimated number of bits of true entropy per 1024 bits read from the rng.

      Defaults to zero which causes the kernel's default quality to be used

      instead.  Note that the default quality is usually zero which disables

      using this rng to automatically fill the kernel's entropy pool.

  reg:

    maxItems: 1

    description:

      Base address to sample from. Currently 'reg' must be at least four bytes

      wide and 32-bit aligned.

required:

  - compatible

  - period

  - reg

additionalProperties: false

examples:

  - |

    rng@44 {

        compatible = "timeriomem_rng";

        reg = <0x44 0x04>;

        period = <1000000>;

    };