* Devantech SRF04 ultrasonic range finder
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Bit-banging driver using two GPIOs
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Required properties:
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- compatible: Should be "devantech,srf04"
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- trig-gpios: 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
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device it should initiate the measurement cycle.
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- echo-gpios: Definition of the GPIO for the echo (input)
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This GPIO is set by the device as soon as an ultrasonic
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burst is sent out and reset when the first echo is
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received.
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Thus this GPIO is set while the ultrasonic waves are doing
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one round trip.
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It needs to be an GPIO which is able to deliver an
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interrupt because the time between two interrupts is
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measured in the driver.
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See Documentation/devicetree/bindings/gpio/gpio.txt for
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information on how to specify a consumer gpio.
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Example:
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srf04@0 {
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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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