0001 # SPDX-License-Identifier: GPL-2.0
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/iio/proximity/devantech-srf04.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: Devantech SRF04 and Maxbotix mb1000 ultrasonic range finder
0008
0009 maintainers:
0010 - Andreas Klinger <ak@it-klinger.de>
0011
0012 description: |
0013 Bit-banging driver using two GPIOs:
0014 - trigger-gpio is raised by the driver to start sending out an ultrasonic
0015 burst
0016 - echo-gpio is held high by the sensor after sending ultrasonic burst
0017 until it is received once again
0018
0019 Specifications about the devices can be found at:
0020 https://www.robot-electronics.co.uk/htm/srf04tech.htm
0021
0022 https://www.maxbotix.com/documents/LV-MaxSonar-EZ_Datasheet.pdf
0023
0024 properties:
0025 compatible:
0026 enum:
0027 - devantech,srf04
0028 - maxbotix,mb1000
0029 - maxbotix,mb1010
0030 - maxbotix,mb1020
0031 - maxbotix,mb1030
0032 - maxbotix,mb1040
0033
0034 trig-gpios:
0035 description:
0036 Definition of the GPIO for the triggering (output)
0037 This GPIO is set for about 10 us by the driver to tell the device it
0038 should initiate the measurement cycle.
0039 See Documentation/devicetree/bindings/gpio/gpio.txt for information
0040 on how to specify a consumer gpio.
0041 maxItems: 1
0042
0043 echo-gpios:
0044 description:
0045 Definition of the GPIO for the echo (input)
0046 This GPIO is set by the device as soon as an ultrasonic burst is sent
0047 out and reset when the first echo is received.
0048 Thus this GPIO is set while the ultrasonic waves are doing one round
0049 trip.
0050 It needs to be an GPIO which is able to deliver an interrupt because
0051 the time between two interrupts is measured in the driver.
0052 maxItems: 1
0053
0054 power-gpios:
0055 description:
0056 Definition of the GPIO for power management of connected peripheral
0057 (output).
0058 This GPIO can be used by the external hardware for power management.
0059 When the device gets suspended it's switched off and when it resumes
0060 it's switched on again. After some period of inactivity the driver
0061 get suspended automatically (autosuspend feature).
0062 maxItems: 1
0063
0064 startup-time-ms:
0065 description:
0066 This is the startup time the device needs after a resume to be up and
0067 running.
0068 minimum: 0
0069 maximum: 1000
0070 default: 100
0071
0072 required:
0073 - compatible
0074 - trig-gpios
0075 - echo-gpios
0076
0077 additionalProperties: false
0078
0079 examples:
0080 - |
0081 #include <dt-bindings/gpio/gpio.h>
0082 proximity {
0083 compatible = "devantech,srf04";
0084 trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
0085 echo-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
0086 };
