diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
index 9bce57862ed6..cda29fd167d9 100644
--- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
+++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.txt
@@ -23,6 +23,8 @@ Required properties:
 
 Optional properties:
 - power-gpios : Specify GPIOs for power control
+- nvidia,pad : Specify the pad ID for controlling the I/O voltage level.
+  Required for 1.8V mode support on Tegra210.
 
 Example: