diff --git a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt
index 60c678a4c994..046a3de026d4 100644
--- a/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt
+++ b/Documentation/devicetree/bindings/pinctrl/st,stm32-pinctrl.txt
@@ -39,9 +39,10 @@ Optional properties:
  - reset:	  : Reference to the reset controller
  - interrupt-parent: phandle of the interrupt parent to which the external
    GPIO interrupts are forwarded to.
- - st,syscfg: Should be phandle/offset pair. The phandle to the syscon node
-   which includes IRQ mux selection register, and the offset of the IRQ mux
-   selection register.
+ - st,syscfg: Should be phandle/offset/mask.
+	-The phandle to the syscon node which includes IRQ mux selection register.
+	-The offset of the IRQ mux selection register
+	-The field mask of IRQ mux, needed if different of 0xf.
  - gpio-ranges: Define a dedicated mapping between a pin-controller and
    a gpio controller. Format is <&phandle a b c> with:
 	-(phandle): phandle of pin-controller.