diff --git a/bindings/iommu/arm,smmu.txt b/bindings/iommu/arm,smmu.txt
index 757b8c46cb92..9e3e515e4e96 100644
--- a/bindings/iommu/arm,smmu.txt
+++ b/bindings/iommu/arm,smmu.txt
@@ -156,6 +156,12 @@ conditions.
                   clients who do not detach, it's not possible to keep regulator
                   vote while smmu is attached. Type is <u32>.
 
+- qcom,iommu-geometry:
+		  Allow clients to set the available IOVA space for fastmap
+		  clients. The new space created will be a superset of the IOVA
+		  range which was created through the qcom,iommu-dma-addr-pool
+		  DT property.
+
 - (%s)-supply   : Phandle of the regulator that should be powered on during
                   SMMU register access. (%s) is a string from the
 		  qcom,regulator-names property.