diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
index 45b4519616123ad5ffb047ec5e6660f8737647a5..e30fd106df4f83e1bcf7c42a6d77f866739f0cad 100644
--- a/Documentation/devicetree/bindings/ata/ahci-platform.txt
+++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
@@ -10,6 +10,7 @@ PHYs.
 Required properties:
 - compatible        : compatible string, one of:
   - "allwinner,sun4i-a10-ahci"
+  - "allwinner,sun8i-r40-ahci"
   - "brcm,iproc-ahci"
   - "hisilicon,hisi-ahci"
   - "cavium,octeon-7130-ahci"
@@ -44,6 +45,7 @@ Required properties when using sub-nodes:
 - #address-cells    : number of cells to encode an address
 - #size-cells       : number of cells representing the size of an address
 
+For allwinner,sun8i-r40-ahci, the reset propertie must be present.
 
 Sub-nodes required properties:
 - reg		    : the port number