diff --git a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
index 0ec68141f85a..a10d1f6d85c6 100644
--- a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
+++ b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt
@@ -18,6 +18,8 @@ Optional properties:
 			 format depends on the interrupt controller.
 			 It should be a DCF interrupt. When DDR DVFS finishes
 			 a DCF interrupt is triggered.
+- rockchip,pmu:		 Phandle to the syscon managing the "PMU general register
+			 files".
 
 Following properties relate to DDR timing: