dt-bindings: pps: pps-gpio PPS ECHO implementation

[linux-2.6-microblaze.git] / Documentation / devicetree / bindings / pps / pps-gpio.txt

diff --git a/Documentation/devicetree/bindings/pps/pps-gpio.txt b/Documentation/devicetree/bindings/pps/pps-gpio.txt
index 3683874..9012a2a 100644 (file)
--- a/Documentation/devicetree/bindings/pps/pps-gpio.txt
+++ b/Documentation/devicetree/bindings/pps/pps-gpio.txt
@@ -7,6 +7,10 @@ Required properties:
 - compatible: should be "pps-gpio"
 - gpios: one PPS GPIO in the format described by ../gpio/gpio.txt
 
+Additional required properties for the PPS ECHO functionality:
+- echo-gpios: one PPS ECHO GPIO in the format described by ../gpio/gpio.txt
+- echo-active-ms: duration in ms of the active portion of the echo pulse
+
 Optional properties:
 - assert-falling-edge: when present, assert is indicated by a falling edge
                        (instead of by a rising edge)
@@ -19,5 +23,8 @@ Example:
                gpios = <&gpio1 26 GPIO_ACTIVE_HIGH>;
                assert-falling-edge;
 
+               echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;
+               echo-active-ms = <100>;
+
                compatible = "pps-gpio";
        };