diff --git a/Documentation/devicetree/bindings/pinctrl/aspeed,ast2600-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/aspeed,ast2600-pinctrl.yaml
index 00b6974a5ed3..80974c46f3ef 100644
--- a/Documentation/devicetree/bindings/pinctrl/aspeed,ast2600-pinctrl.yaml
+++ b/Documentation/devicetree/bindings/pinctrl/aspeed,ast2600-pinctrl.yaml
@@ -19,6 +19,11 @@ description: |+
   Refer to the bindings described in
   Documentation/devicetree/bindings/mfd/syscon.yaml
 
+  Note: According to the NCSI specification, the reference clock output pin
+  (RMIIXRCLKO) is not required on the management controller side. To optimize
+  pin usage, add "NCSI" pin groups that are equivalent to the RMII pin groups,
+  but without the RMIIXRCLKO pin.
+
 properties:
   compatible:
     const: aspeed,ast2600-pinctrl
@@ -337,6 +342,8 @@ additionalProperties:
         - MDIO2
         - MDIO3
         - MDIO4
+        - NCSI3
+        - NCSI4
         - NCTS1
         - NCTS2
         - NCTS3