devantech-srf04.yaml: transform DT binding to YAML

* Devantech SRF04 ultrasonic range finder

  Bit-banging driver using two GPIOs

Required properties:

 - compatible:	Should be "devantech,srf04"

 - trig-gpios:	Definition of the GPIO for the triggering (output)

		This GPIO is set for about 10 us by the driver to tell the

		device it should initiate the measurement cycle.

 - echo-gpios:	Definition of the GPIO for the echo (input)

		This GPIO is set by the device as soon as an ultrasonic

		burst is sent out and reset when the first echo is

		received.

		Thus this GPIO is set while the ultrasonic waves are doing

		one round trip.

		It needs to be an GPIO which is able to deliver an

		interrupt because the time between two interrupts is

		measured in the driver.

		See Documentation/devicetree/bindings/gpio/gpio.txt for

		information on how to specify a consumer gpio.

Example:

srf04@0 {

	compatible = "devantech,srf04";

	trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;

	echo-gpios = <&gpio2  6 GPIO_ACTIVE_HIGH>;

};

# SPDX-License-Identifier: GPL-2.0

%YAML 1.2

---

$id: http://devicetree.org/schemas/iio/proximity/devantech-srf04.yaml#

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

title: Devantech SRF04 ultrasonic range finder

maintainers:

  - Andreas Klinger <ak@it-klinger.de>

description: |

  Bit-banging driver using two GPIOs:

  - trigger-gpio is raised by the driver to start sending out an ultrasonic

    burst

  - echo-gpio is held high by the sensor after sending ultrasonic burst

    until it is received once again

  Specifications about the driver can be found at:

  http://www.robot-electronics.co.uk/htm/srf04tech.htm

properties:

  compatible:

    items:

      - const: devantech,srf04

  trig-gpios:

    description:

      Definition of the GPIO for the triggering (output) This GPIO is set

      for about 10 us by the driver to tell the device it should initiate

      the measurement cycle.

    maxItems: 1

  echo-gpios:

    description:

      Definition of the GPIO for the echo (input)

      This GPIO is set by the device as soon as an ultrasonic burst is sent

      out and reset when the first echo is received.

      Thus this GPIO is set while the ultrasonic waves are doing one round

      trip.

      It needs to be an GPIO which is able to deliver an interrupt because

      the time between two interrupts is measured in the driver.

      See Documentation/devicetree/bindings/gpio/gpio.txt for information

      on how to specify a consumer gpio.

    maxItems: 1

required:

  - compatible

  - trig-gpios

  - echo-gpios

examples:

  - |

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

    proximity {

        compatible = "devantech,srf04";

        trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;

        echo-gpios = <&gpio2  6 GPIO_ACTIVE_HIGH>;

    };