diff --git a/Documentation/devicetree/bindings/mfd/axp20x.txt b/Documentation/devicetree/bindings/mfd/axp20x.txt
index 8f3ad9ab4637..b41d2601c6ba 100644
--- a/Documentation/devicetree/bindings/mfd/axp20x.txt
+++ b/Documentation/devicetree/bindings/mfd/axp20x.txt
@@ -28,6 +28,9 @@ Optional properties:
 		  regulator to drive the OTG VBus, rather then as an input pin
 		  which signals whether the board is driving OTG VBus or not.
 
+- x-powers,master-mode: Boolean (axp806 only). Set this when the PMIC is
+			wired for master mode. The default is slave mode.
+
 - <input>-supply: a phandle to the regulator supply node. May be omitted if
 		  inputs are unregulated, such as using the IPSOUT output
 		  from the PMIC.