diff --git a/Documentation/devicetree/bindings/spi/spi-dw.txt b/Documentation/devicetree/bindings/spi/spi-dw.txt
index 7b63ed6..034dbdd 100644
--- a/Documentation/devicetree/bindings/spi/spi-dw.txt
+++ b/Documentation/devicetree/bindings/spi/spi-dw.txt
@@ -11,6 +11,7 @@ Required properties:
 
 Optional properties:
 - cs-gpios: see spi-bus.txt
+- 32bit_access : use 32 bit register accesses
 
 Example: