87 lines
2.5 KiB
YAML
87 lines
2.5 KiB
YAML
# SPDX-License-Identifier: GPL-2.0
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/iio/proximity/devantech-srf04.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: Devantech SRF04 and Maxbotix mb1000 ultrasonic range finder
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maintainers:
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- Andreas Klinger <ak@it-klinger.de>
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description: |
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Bit-banging driver using two GPIOs:
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- trigger-gpio is raised by the driver to start sending out an ultrasonic
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burst
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- echo-gpio is held high by the sensor after sending ultrasonic burst
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until it is received once again
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Specifications about the devices can be found at:
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https://www.robot-electronics.co.uk/htm/srf04tech.htm
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https://www.maxbotix.com/documents/LV-MaxSonar-EZ_Datasheet.pdf
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properties:
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compatible:
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enum:
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- devantech,srf04
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- maxbotix,mb1000
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- maxbotix,mb1010
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- maxbotix,mb1020
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- maxbotix,mb1030
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- maxbotix,mb1040
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trig-gpios:
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description:
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Definition of the GPIO for the triggering (output)
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This GPIO is set for about 10 us by the driver to tell the device it
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should initiate the measurement cycle.
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See Documentation/devicetree/bindings/gpio/gpio.txt for information
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on how to specify a consumer gpio.
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maxItems: 1
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echo-gpios:
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description:
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Definition of the GPIO for the echo (input)
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This GPIO is set by the device as soon as an ultrasonic burst is sent
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out and reset when the first echo is received.
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Thus this GPIO is set while the ultrasonic waves are doing one round
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trip.
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It needs to be an GPIO which is able to deliver an interrupt because
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the time between two interrupts is measured in the driver.
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maxItems: 1
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power-gpios:
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description:
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Definition of the GPIO for power management of connected peripheral
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(output).
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This GPIO can be used by the external hardware for power management.
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When the device gets suspended it's switched off and when it resumes
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it's switched on again. After some period of inactivity the driver
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get suspended automatically (autosuspend feature).
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maxItems: 1
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startup-time-ms:
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description:
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This is the startup time the device needs after a resume to be up and
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running.
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minimum: 0
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maximum: 1000
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default: 100
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required:
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- compatible
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- trig-gpios
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- echo-gpios
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additionalProperties: false
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examples:
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- |
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#include <dt-bindings/gpio/gpio.h>
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proximity {
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compatible = "devantech,srf04";
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trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
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echo-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
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};
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