xref: /linux/Documentation/devicetree/bindings/iio/proximity/devantech-srf04.yaml (revision 932f98922f6fca9f8c45274346b49058dd50d51a) 
1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/iio/proximity/devantech-srf04.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Devantech SRF04 ultrasonic range finder
8
9maintainers:
10  - Andreas Klinger <ak@it-klinger.de>
11
12description: |
13  Bit-banging driver using two GPIOs:
14  - trigger-gpio is raised by the driver to start sending out an ultrasonic
15    burst
16  - echo-gpio is held high by the sensor after sending ultrasonic burst
17    until it is received once again
18
19  Specifications about the driver can be found at:
20  http://www.robot-electronics.co.uk/htm/srf04tech.htm
21
22properties:
23  compatible:
24    items:
25      - const: devantech,srf04
26
27  trig-gpios:
28    description:
29      Definition of the GPIO for the triggering (output) This GPIO is set
30      for about 10 us by the driver to tell the device it should initiate
31      the measurement cycle.
32    maxItems: 1
33
34  echo-gpios:
35    description:
36      Definition of the GPIO for the echo (input)
37      This GPIO is set by the device as soon as an ultrasonic burst is sent
38      out and reset when the first echo is received.
39      Thus this GPIO is set while the ultrasonic waves are doing one round
40      trip.
41      It needs to be an GPIO which is able to deliver an interrupt because
42      the time between two interrupts is measured in the driver.
43      See Documentation/devicetree/bindings/gpio/gpio.txt for information
44      on how to specify a consumer gpio.
45    maxItems: 1
46
47required:
48  - compatible
49  - trig-gpios
50  - echo-gpios
51
52examples:
53  - |
54    #include <dt-bindings/gpio/gpio.h>
55    proximity {
56        compatible = "devantech,srf04";
57        trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
58        echo-gpios = <&gpio2  6 GPIO_ACTIVE_HIGH>;
59    };
60