dt-bindings: counter: add interrupt-counter binding

# SPDX-License-Identifier: GPL-2.0

%YAML 1.2

---

$id: http://devicetree.org/schemas/counter/interrupt-counter.yaml#

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

title: Interrupt counter

maintainers:

  - Oleksij Rempel <o.rempel@pengutronix.de>

description: |

  A generic interrupt counter to measure interrupt frequency. It was developed

  and used for agricultural devices to measure rotation speed of wheels or

  other tools. Since the direction of rotation is not important, only one

  signal line is needed.

  Interrupts or gpios are required. If both are defined, the interrupt will

  take precedence for counting interrupts.

properties:

  compatible:

    const: interrupt-counter

  interrupts:

    maxItems: 1

  gpios:

    maxItems: 1

required:

  - compatible

anyOf:

  - required: [ interrupts-extended ]

  - required: [ interrupts ]

  - required: [ gpios ]

additionalProperties: false

examples:

  - |

    #include <dt-bindings/interrupt-controller/irq.h>

    #include <dt-bindings/gpio/gpio.h>

    counter-0 {

        compatible = "interrupt-counter";

        interrupts-extended = <&gpio 0 IRQ_TYPE_EDGE_RISING>;

    };

    counter-1 {

        compatible = "interrupt-counter";

        gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;

    };

    counter-2 {

        compatible = "interrupt-counter";

        interrupts-extended = <&gpio 2 IRQ_TYPE_EDGE_RISING>;

        gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;

    };

...