diff --git a/drivers/renesas/rcar/iic_dvfs/iic_dvfs.h b/drivers/renesas/rcar/iic_dvfs/iic_dvfs.h
index 2dec58f..244c06c 100644
--- a/drivers/renesas/rcar/iic_dvfs/iic_dvfs.h
+++ b/drivers/renesas/rcar/iic_dvfs/iic_dvfs.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2017, Renesas Electronics Corporation. All rights reserved.
+ * Copyright (c) 2015-2021, Renesas Electronics Corporation. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -8,14 +8,14 @@
 #define IIC_DVFS_H
 
 /* PMIC slave */
-#define PMIC			(0x30)
-#define	BKUP_MODE_CNT		(0x20)
-#define	DVFS_SET_VID		(0x54)
-#define	REG_KEEP10		(0x79)
+#define PMIC			(0x30U)
+#define BKUP_MODE_CNT		(0x20U)
+#define DVFS_SET_VID		(0x54U)
+#define REG_KEEP10		(0x79U)
 
 /* EEPROM slave */
-#define EEPROM			(0x50)
-#define	BOARD_ID		(0x70)
+#define EEPROM			(0x50U)
+#define BOARD_ID		(0x70U)
 
 int32_t rcar_iic_dvfs_receive(uint8_t slave, uint8_t reg, uint8_t *data);
 int32_t rcar_iic_dvfs_send(uint8_t slave, uint8_t regr, uint8_t data);