diff --git a/plat/mediatek/common/mtk_plat_common.c b/plat/mediatek/common/mtk_plat_common.c
index 142b5c9..978d4e5 100644
--- a/plat/mediatek/common/mtk_plat_common.c
+++ b/plat/mediatek/common/mtk_plat_common.c
@@ -28,7 +28,7 @@
 				u_register_t *px4)
 {
 	/* if parameters from SMC32. Clean top 32 bits */
-	if (0 == (smc_fid & SMC_AARCH64_BIT)) {
+	if (GET_SMC_CC(smc_fid) == SMC_64) {
 		*px1 = *px1 & SMC32_PARAM_MASK;
 		*px2 = *px2 & SMC32_PARAM_MASK;
 		*px3 = *px3 & SMC32_PARAM_MASK;
diff --git a/plat/mediatek/common/mtk_sip_svc.h b/plat/mediatek/common/mtk_sip_svc.h
deleted file mode 100644
index 74b17b6..0000000
--- a/plat/mediatek/common/mtk_sip_svc.h
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-#ifndef MTK_SIP_SVC_H
-#define MTK_SIP_SVC_H
-
-#include <stdint.h>
-
-/* SMC function IDs for SiP Service queries */
-#define SIP_SVC_CALL_COUNT		0x8200ff00
-#define SIP_SVC_UID			0x8200ff01
-/*					0x8200ff02 is reserved */
-#define SIP_SVC_VERSION			0x8200ff03
-
-/* Mediatek SiP Service Calls version numbers */
-#define MTK_SIP_SVC_VERSION_MAJOR	0x0
-#define MTK_SIP_SVC_VERSION_MINOR	0x1
-
-#define SMC_AARCH64_BIT		0x40000000
-
-/* Number of Mediatek SiP Calls implemented */
-#define MTK_COMMON_SIP_NUM_CALLS	4
-
-/* Mediatek SiP Service Calls function IDs */
-#define MTK_SIP_SET_AUTHORIZED_SECURE_REG	0x82000001
-
-/* For MTK SMC from Secure OS */
-/* 0x82000000 - 0x820000FF & 0xC2000000 - 0xC20000FF */
-#define MTK_SIP_KERNEL_BOOT_AARCH32		0x82000200
-#define MTK_SIP_KERNEL_BOOT_AARCH64		0xC2000200
-
-/* VCORE */
-#define MTK_SIP_VCORE_CONTROL_ARCH32		0x82000506
-#define MTK_SIP_VCORE_CONTROL_ARCH64		0xC2000506
-
-/* APUSYS SMC call */
-#define MTK_SIP_APUSYS_CONTROL_AARCH32		0x8200051E
-#define MTK_SIP_APUSYS_CONTROL_AARCH64		0xC200051E
-
-/* Mediatek SiP Calls error code */
-enum {
-	MTK_SIP_E_SUCCESS = 0,
-	MTK_SIP_E_INVALID_PARAM = -1,
-	MTK_SIP_E_NOT_SUPPORTED = -2,
-	MTK_SIP_E_INVALID_RANGE = -3,
-	MTK_SIP_E_PERMISSION_DENY = -4,
-	MTK_SIP_E_LOCK_FAIL = -5
-};
-
-/*
- * This function should be implemented in Mediatek SOC directory. It fullfills
- * MTK_SIP_SET_AUTHORIZED_SECURE_REG SiP call by checking the sreg with the
- * predefined secure register list, if a match was found, set val to sreg.
- *
- * Return MTK_SIP_E_SUCCESS on success, and MTK_SIP_E_INVALID_PARAM on failure.
- */
-uint64_t mt_sip_set_authorized_sreg(uint32_t sreg, uint32_t val);
-
-#endif /* MTK_SIP_SVC_H */