diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index c735303..c9cfa83 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1675,3 +1675,10 @@
 Contact:	linux-iio@vger.kernel.org
 Description:
 		Raw counter device counters direction for channel Y.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_phaseY_raw
+KernelVersion:	4.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Raw (unscaled) phase difference reading from channel Y
+		that can be processed to radians.
\ No newline at end of file