diff --git a/Documentation/devicetree/bindings/mmc/orion-sdio.txt b/Documentation/devicetree/bindings/mmc/orion-sdio.txt
new file mode 100644
index 0000000..84f0ebd
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+++ b/Documentation/devicetree/bindings/mmc/orion-sdio.txt
@@ -0,0 +1,17 @@
+* Marvell orion-sdio controller
+
+This file documents differences between the core properties in mmc.txt
+and the properties used by the orion-sdio driver.
+
+- compatible: Should be "marvell,orion-sdio"
+- clocks: reference to the clock of the SDIO interface
+
+Example:
+
+	mvsdio@d00d4000 {
+		compatible = "marvell,orion-sdio";
+		reg = <0xd00d4000 0x200>;
+		interrupts = <54>;
+		clocks = <&gateclk 17>;
+		status = "disabled";
+	};