dt-bindings: pps: pps-gpio: Convert to yaml

Device-Tree Bindings for a PPS Signal on GPIO

These properties describe a PPS (pulse-per-second) signal connected to

a GPIO pin.

Required properties:

- compatible: should be "pps-gpio"

- gpios: one PPS GPIO in the format described by ../gpio/gpio.txt

Additional required properties for the PPS ECHO functionality:

- echo-gpios: one PPS ECHO GPIO in the format described by ../gpio/gpio.txt

- echo-active-ms: duration in ms of the active portion of the echo pulse

Optional properties:

- assert-falling-edge: when present, assert is indicated by a falling edge

                       (instead of by a rising edge)

Example:

	pps {

		pinctrl-names = "default";

		pinctrl-0 = <&pinctrl_pps>;

		gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;

		assert-falling-edge;

		echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;

		echo-active-ms = <100>;

		compatible = "pps-gpio";

	};

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

%YAML 1.2

---

$id: http://devicetree.org/schemas/pps/pps-gpio.yaml#

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

title: PPS Signal via GPIO

maintainers:

  - Fabio Estevam <festevam@gmail.com>

properties:

  compatible:

    const: pps-gpio

  gpios:

    description: The GPIO that provides the PPS signal.

    maxItems: 1

  echo-gpios:

    description: The GPIO that provides the PPS ECHO signal.

    maxItems: 1

  echo-active-ms:

    description: Duration in ms of the active portion of the echo pulse.

  assert-falling-edge:

    description: Indicates a falling edge assert, when present. Rising edge if absent.

    type: boolean

required:

  - compatible

  - gpios

additionalProperties: false

examples:

  - |

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

      pps {

          compatible = "pps-gpio";

          pinctrl-names = "default";

          pinctrl-0 = <&pinctrl_pps>;

          gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;

          assert-falling-edge;

          echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;

          echo-active-ms = <100>;

      };