diff --git a/plat/mediatek/drivers/iommu/mtk_iommu_priv.h b/plat/mediatek/drivers/iommu/mtk_iommu_priv.h
new file mode 100644
index 0000000..3404d31
--- /dev/null
+++ b/plat/mediatek/drivers/iommu/mtk_iommu_priv.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2022, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef IOMMU_PRIV_H
+#define IOMMU_PRIV_H
+
+#include <common/debug.h>
+#include <lib/mmio.h>
+#include <mtk_sip_svc.h>
+
+#define LARB_CFG_ENTRY(bs, p_nr, dom)			\
+	{ .base = (bs), .port_nr = (p_nr),		\
+	  .dom_id = (dom), .to_sram = 0, }
+
+#define LARB_CFG_ENTRY_WITH_PATH(bs, p_nr, dom, sram)	\
+	{ .base = (bs), .port_nr = (p_nr),		\
+	  .dom_id = (dom), .to_sram = (sram), }
+
+#define IFR_MST_CFG_ENTRY(idx, bit)	\
+	{ .cfg_addr_idx = (idx), .r_mmu_en_bit = (bit), }
+
+enum IOMMU_ATF_CMD {
+	IOMMU_ATF_CMD_CONFIG_SMI_LARB,		/* For mm master to enable iommu */
+	IOMMU_ATF_CMD_CONFIG_INFRA_IOMMU,	/* For infra master to enable iommu */
+	IOMMU_ATF_CMD_COUNT,
+};
+
+struct mtk_smi_larb_config {
+	uint32_t base;
+	uint32_t port_nr;
+	uint32_t dom_id;
+	uint32_t to_sram;
+	uint32_t sec_en_msk;
+};
+
+struct mtk_ifr_mst_config {
+	uint8_t cfg_addr_idx;
+	uint8_t r_mmu_en_bit;
+};
+
+#endif	/* IOMMU_PRIV_H */