1*4882a593SmuzhiyunDevice-Tree Bindings for a PPS Signal on GPIO 2*4882a593Smuzhiyun 3*4882a593SmuzhiyunThese properties describe a PPS (pulse-per-second) signal connected to 4*4882a593Smuzhiyuna GPIO pin. 5*4882a593Smuzhiyun 6*4882a593SmuzhiyunRequired properties: 7*4882a593Smuzhiyun- compatible: should be "pps-gpio" 8*4882a593Smuzhiyun- gpios: one PPS GPIO in the format described by ../gpio/gpio.txt 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunAdditional required properties for the PPS ECHO functionality: 11*4882a593Smuzhiyun- echo-gpios: one PPS ECHO GPIO in the format described by ../gpio/gpio.txt 12*4882a593Smuzhiyun- echo-active-ms: duration in ms of the active portion of the echo pulse 13*4882a593Smuzhiyun 14*4882a593SmuzhiyunOptional properties: 15*4882a593Smuzhiyun- assert-falling-edge: when present, assert is indicated by a falling edge 16*4882a593Smuzhiyun (instead of by a rising edge) 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunExample: 19*4882a593Smuzhiyun pps { 20*4882a593Smuzhiyun pinctrl-names = "default"; 21*4882a593Smuzhiyun pinctrl-0 = <&pinctrl_pps>; 22*4882a593Smuzhiyun 23*4882a593Smuzhiyun gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>; 24*4882a593Smuzhiyun assert-falling-edge; 25*4882a593Smuzhiyun 26*4882a593Smuzhiyun echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>; 27*4882a593Smuzhiyun echo-active-ms = <100>; 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun compatible = "pps-gpio"; 30*4882a593Smuzhiyun }; 31