diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 22d1e1f3f38b..ac7b6a1d835a 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -102,11 +102,13 @@ Required host node properties when using function subnodes:
 - #size-cells: should be zero.
 
 Required function subnode properties:
-- compatible: name of SDIO function following generic names recommended practice
 - reg: Must contain the SDIO function number of the function this subnode
        describes. A value of 0 denotes the memory SD function, values from
        1 to 7 denote the SDIO functions.
 
+Optional function subnode properties:
+- compatible: name of SDIO function following generic names recommended practice
+
 
 Examples
 --------