This patch implements the device tree changes required for the pps
echo functionality for pps-gpio, that sysfs claims is available
already.
This patch was originally written by Lukas Senger as part of a masters
thesis project and modified for inclusion into the linux kernel by Tom
Burkart.
Signed-off-by: Lukas Senger <lu...@fridolin.com>
Signed-off-by: Tom Burkart <t...@aussec.com>
---
Documentation/devicetree/bindings/pps/pps-gpio.txt | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/Documentation/devicetree/bindings/pps/pps-gpio.txt
b/Documentation/devicetree/bindings/pps/pps-gpio.txt
index 6c9fc0998d94..f85dbe4ce0b3 100644
--- a/Documentation/devicetree/bindings/pps/pps-gpio.txt
+++ b/Documentation/devicetree/bindings/pps/pps-gpio.txt
@@ -9,10 +9,15 @@ Required properties:
Alternatively (DEPRECATED), instead of pps-gpios above, it may have:
- gpios: one PPS GPIO as above
+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)
- capture-clear: when present, also capture the PPS clear event
+- invert-pps-echo: when present, invert the PPS ECHO pulse
Example:
pps {
@@ -23,5 +28,9 @@ Example:
assert-falling-edge;
capture-clear;
+ echo-gpios = <&gpio1 27 GPIO_ACTIVE_HIGH>;
+ echo-active-ms = <100>;
+ invert-pps-echo;
+
compatible = "pps-gpio";
};
--
2.12.3
