blob: d4dc7a227e2ed8840cf2ca861661dd9bedd1cdee (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
|
* Devantech SRF04 ultrasonic range finder
Bit-banging driver using two GPIOs
Required properties:
- compatible: Should be "devantech,srf04"
- trig-gpios: Definition of the GPIO for the triggering (output)
This GPIO is set for about 10 us by the driver to tell the
device it should initiate the measurement cycle.
- echo-gpios: Definition of the GPIO for the echo (input)
This GPIO is set by the device as soon as an ultrasonic
burst is sent out and reset when the first echo is
received.
Thus this GPIO is set while the ultrasonic waves are doing
one round trip.
It needs to be an GPIO which is able to deliver an
interrupt because the time between two interrupts is
measured in the driver.
See Documentation/devicetree/bindings/gpio/gpio.txt for
information on how to specify a consumer gpio.
Example:
srf04@0 {
compatible = "devantech,srf04";
trig-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
echo-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
};
|
