diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,audsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,audsys.txt
index 9b8f578d5e19..97b304eaa47c 100644
--- a/Documentation/devicetree/bindings/arm/mediatek/mediatek,audsys.txt
+++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,audsys.txt
@@ -13,10 +13,19 @@ The AUDSYS controller uses the common clk binding from
 Documentation/devicetree/bindings/clock/clock-bindings.txt
 The available clocks are defined in dt-bindings/clock/mt*-clk.h.
 
+Required sub-nodes:
+-------
+For common binding part and usage, refer to
+../sonud/mt2701-afe-pcm.txt.
+
 Example:
 
-audsys: audsys@11220000 {
-	compatible = "mediatek,mt7622-audsys", "syscon";
-	reg = <0 0x11220000 0 0x1000>;
-	#clock-cells = <1>;
-};
+	audsys: clock-controller@11220000 {
+		compatible = "mediatek,mt7622-audsys", "syscon";
+		reg = <0 0x11220000 0 0x2000>;
+		#clock-cells = <1>;
+
+		afe: audio-controller {
+			...
+		};
+	};