diff --git a/Documentation/devicetree/bindings/mfd/mt6397.txt b/Documentation/devicetree/bindings/mfd/mt6397.txt
index ab3163a60929..5fccf987865b 100644
--- a/Documentation/devicetree/bindings/mfd/mt6397.txt
+++ b/Documentation/devicetree/bindings/mfd/mt6397.txt
@@ -22,8 +22,10 @@ compatible: "mediatek,mt6397" or "mediatek,mt6323"
 Optional subnodes:
 
 - rtc
-	Required properties:
+	Required properties: Should be one of follows
+		- compatible: "mediatek,mt6323-rtc"
 		- compatible: "mediatek,mt6397-rtc"
+	For details, see ../rtc/rtc-mt6397.txt
 - regulators
 	Required properties:
 		- compatible: "mediatek,mt6397-regulator"