diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
index 2c71454ae8e3..824bbe4333b7 100644
--- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml
+++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml
@@ -232,6 +232,12 @@ properties:
       PHY's that have configurable TX internal delays. If this property is
       present then the PHY applies the TX delay.
 
+  tx-amplitude-100base-tx-percent:
+    description:
+      Transmit amplitude gain applied for 100BASE-TX. 100% matches 2V
+      peak-to-peak specified in ANSI X3.263. When omitted, the PHYs default
+      will be left as is.
+
   leds:
     type: object