1* Devantech SRF04 ultrasonic range finder 2 Bit-banging driver using two GPIOs 3 4Required properties: 5 - compatible: Should be "devantech,srf04" 6 7 - trig-gpios: Definition of the GPIO for the triggering (output) 8 This GPIO is set for about 10 us by the driver to tell the 9 device it should initiate the measurement cycle. 10 11 - echo-gpios: Definition of the GPIO for the echo (input) 12 This GPIO is set by the device as soon as an ultrasonic 13 burst is sent out and reset when the first echo is 14 received. 15 Thus this GPIO is set while the ultrasonic waves are doing 16 one round trip. 17 It needs to be an GPIO which is able to deliver an 18 interrupt because the time between two interrupts is 19 measured in the driver. 20 See Documentation/devicetree/bindings/gpio/gpio.txt for 21 information on how to specify a consumer gpio. 22 23Example: 24srf04@0 { 25 compatible = "devantech,srf04"; 26 trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>; 27 echo-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>; 28}; 29