1*4882a593Smuzhiyun# SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) 2*4882a593Smuzhiyun%YAML 1.2 3*4882a593Smuzhiyun--- 4*4882a593Smuzhiyun$id: http://devicetree.org/schemas/iio/proximity/parallax-ping.yaml# 5*4882a593Smuzhiyun$schema: http://devicetree.org/meta-schemas/core.yaml# 6*4882a593Smuzhiyun 7*4882a593Smuzhiyuntitle: Parallax PING))) and LaserPING range finder 8*4882a593Smuzhiyun 9*4882a593Smuzhiyunmaintainers: 10*4882a593Smuzhiyun - Andreas Klinger <ak@it-klinger.de> 11*4882a593Smuzhiyun 12*4882a593Smuzhiyundescription: | 13*4882a593Smuzhiyun Bit-banging driver using one GPIO: 14*4882a593Smuzhiyun - ping-gpios is raised by the driver to start measurement 15*4882a593Smuzhiyun - direction of ping-gpio is then switched into input with an interrupt 16*4882a593Smuzhiyun for receiving distance value as PWM signal 17*4882a593Smuzhiyun 18*4882a593Smuzhiyun Specifications about the devices can be found at: 19*4882a593Smuzhiyun http://parallax.com/sites/default/files/downloads/28041-LaserPING-2m-Rangefinder-Guide.pdf 20*4882a593Smuzhiyun http://parallax.com/sites/default/files/downloads/28015-PING-Documentation-v1.6.pdf 21*4882a593Smuzhiyun 22*4882a593Smuzhiyunproperties: 23*4882a593Smuzhiyun compatible: 24*4882a593Smuzhiyun enum: 25*4882a593Smuzhiyun - parallax,ping 26*4882a593Smuzhiyun - parallax,laserping 27*4882a593Smuzhiyun 28*4882a593Smuzhiyun ping-gpios: 29*4882a593Smuzhiyun description: 30*4882a593Smuzhiyun Definition of the GPIO for the triggering and echo (output and input) 31*4882a593Smuzhiyun This GPIO is set for about 5 us by the driver to tell the device it 32*4882a593Smuzhiyun should initiate the measurement cycle. Afterwards the GPIO is switched 33*4882a593Smuzhiyun to input direction with an interrupt. The device sets it and the 34*4882a593Smuzhiyun length of the input signal corresponds to the measured distance. 35*4882a593Smuzhiyun It needs to be an GPIO which is able to deliver an interrupt because 36*4882a593Smuzhiyun the time between two interrupts is measured in the driver. 37*4882a593Smuzhiyun See Documentation/devicetree/bindings/gpio/gpio.txt for information 38*4882a593Smuzhiyun on how to specify a consumer gpio. 39*4882a593Smuzhiyun maxItems: 1 40*4882a593Smuzhiyun 41*4882a593Smuzhiyunrequired: 42*4882a593Smuzhiyun - compatible 43*4882a593Smuzhiyun - ping-gpios 44*4882a593Smuzhiyun 45*4882a593SmuzhiyunadditionalProperties: false 46*4882a593Smuzhiyun 47*4882a593Smuzhiyunexamples: 48*4882a593Smuzhiyun - | 49*4882a593Smuzhiyun #include <dt-bindings/gpio/gpio.h> 50*4882a593Smuzhiyun proximity { 51*4882a593Smuzhiyun compatible = "parallax,laserping"; 52*4882a593Smuzhiyun ping-gpios = <&gpio0 26 GPIO_ACTIVE_HIGH>; 53*4882a593Smuzhiyun }; 54