diff --git a/include/drivers/arm/tzc380.h b/include/drivers/arm/tzc380.h
index a8098a2..9bd5f21 100644
--- a/include/drivers/arm/tzc380.h
+++ b/include/drivers/arm/tzc380.h
@@ -121,6 +121,11 @@
 #define TZC_REGION_SIZE_8E		U(0x3e)
 #define TZC_REGION_SIZE_16E		U(0x3f)
 
+#define TZC_SUBREGION_DIS_SHIFT		0x8
+#define TZC_SUBREGION_DIS_MASK		U(0xff)
+#define TZC_ATTR_SUBREG_DIS(s)		(((s) & TZC_SUBREGION_DIS_MASK) \
+						<< TZC_SUBREGION_DIS_SHIFT)
+
 #define TZC_REGION_SIZE_SHIFT		0x1
 #define TZC_REGION_SIZE_MASK		U(0x7e)
 #define TZC_ATTR_REGION_SIZE(s)		((s) << TZC_REGION_SIZE_SHIFT)