diff --git a/drivers/renesas/rcar/iic_dvfs/iic_dvfs.c b/drivers/renesas/rcar/iic_dvfs/iic_dvfs.c
new file mode 100644
index 0000000..11d52bf
--- /dev/null
+++ b/drivers/renesas/rcar/iic_dvfs/iic_dvfs.c
@@ -0,0 +1,568 @@
+/*
+ * Copyright (c) 2015-2018, Renesas Electronics Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <mmio.h>
+#include <debug.h>
+#include "rcar_def.h"
+#include "cpg_registers.h"
+#include "iic_dvfs.h"
+#include "rcar_private.h"
+
+#define DVFS_RETRY_MAX				(2U)
+
+#define IIC_DVFS_SET_ICCL_EXTAL_TYPE_0		(0x07)
+#define IIC_DVFS_SET_ICCL_EXTAL_TYPE_1		(0x09)
+#define IIC_DVFS_SET_ICCL_EXTAL_TYPE_2		(0x0B)
+#define IIC_DVFS_SET_ICCL_EXTAL_TYPE_3		(0x0E)
+#define IIC_DVFS_SET_ICCL_EXTAL_TYPE_E		(0x15)
+
+#define IIC_DVFS_SET_ICCH_EXTAL_TYPE_0		(0x01)
+#define IIC_DVFS_SET_ICCH_EXTAL_TYPE_1		(0x02)
+#define IIC_DVFS_SET_ICCH_EXTAL_TYPE_2		(0x03)
+#define IIC_DVFS_SET_ICCH_EXTAL_TYPE_3		(0x05)
+#define IIC_DVFS_SET_ICCH_EXTAL_TYPE_E		(0x07)
+
+#define CPG_BIT_SMSTPCR9_DVFS			(0x04000000)
+
+#define IIC_DVFS_REG_BASE			(0xE60B0000)
+#define IIC_DVFS_REG_ICDR			(IIC_DVFS_REG_BASE + 0x0000)
+#define IIC_DVFS_REG_ICCR			(IIC_DVFS_REG_BASE + 0x0004)
+#define IIC_DVFS_REG_ICSR			(IIC_DVFS_REG_BASE + 0x0008)
+#define IIC_DVFS_REG_ICIC			(IIC_DVFS_REG_BASE + 0x000C)
+#define IIC_DVFS_REG_ICCL			(IIC_DVFS_REG_BASE + 0x0010)
+#define IIC_DVFS_REG_ICCH			(IIC_DVFS_REG_BASE + 0x0014)
+
+#define IIC_DVFS_BIT_ICSR_BUSY			(0x10)
+#define IIC_DVFS_BIT_ICSR_AL			(0x08)
+#define IIC_DVFS_BIT_ICSR_TACK			(0x04)
+#define IIC_DVFS_BIT_ICSR_WAIT			(0x02)
+#define IIC_DVFS_BIT_ICSR_DTE			(0x01)
+
+#define IIC_DVFS_BIT_ICCR_ENABLE		(0x80)
+#define IIC_DVFS_SET_ICCR_START			(0x94)
+#define IIC_DVFS_SET_ICCR_STOP			(0x90)
+#define	IIC_DVFS_SET_ICCR_RETRANSMISSION	(0x94)
+#define	IIC_DVFS_SET_ICCR_CHANGE		(0x81)
+#define	IIC_DVFS_SET_ICCR_STOP_READ		(0xC0)
+
+#define IIC_DVFS_BIT_ICIC_TACKE			(0x04)
+#define IIC_DVFS_BIT_ICIC_WAITE			(0x02)
+#define IIC_DVFS_BIT_ICIC_DTEE			(0x01)
+
+#define	DVFS_READ_MODE				(0x01)
+#define	DVFS_WRITE_MODE				(0x00)
+
+#define IIC_DVFS_SET_DUMMY			(0x52)
+#define IIC_DVFS_SET_BUSY_LOOP			(500000000U)
+
+typedef enum {
+	DVFS_START = 0,
+	DVFS_STOP,
+	DVFS_RETRANSMIT,
+	DVFS_READ,
+	DVFS_STOP_READ,
+	DVFS_SET_SLAVE_READ,
+	DVFS_SET_SLAVE,
+	DVFS_WRITE_ADDR,
+	DVFS_WRITE_DATA,
+	DVFS_CHANGE_SEND_TO_RECIEVE,
+	DVFS_DONE,
+} DVFS_STATE_T;
+
+#define DVFS_PROCESS			(1)
+#define DVFS_COMPLETE			(0)
+#define DVFS_ERROR			(-1)
+
+#if IMAGE_BL31
+#define IIC_DVFS_FUNC(__name, ...)					\
+static int32_t 	__attribute__ ((section (".system_ram")))		\
+dvfs_ ##__name(__VA_ARGS__)
+
+#define RCAR_DVFS_API(__name, ...)					\
+int32_t __attribute__ ((section (".system_ram"))) 			\
+rcar_iic_dvfs_ ##__name(__VA_ARGS__)
+
+#else
+#define IIC_DVFS_FUNC(__name, ...) 					\
+static int32_t dvfs_ ##__name(__VA_ARGS__)
+
+#define RCAR_DVFS_API(__name, ...)					\
+int32_t rcar_iic_dvfs_ ##__name(__VA_ARGS__)
+#endif
+
+IIC_DVFS_FUNC(check_error, DVFS_STATE_T *state, uint32_t *err, uint8_t mode)
+{
+	uint8_t icsr_al = 0, icsr_tack = 0;
+	uint8_t reg, stop;
+	uint32_t i = 0;
+
+	stop = mode == DVFS_READ_MODE ? IIC_DVFS_SET_ICCR_STOP_READ :
+	    IIC_DVFS_SET_ICCR_STOP;
+
+	reg = mmio_read_8(IIC_DVFS_REG_ICSR);
+	icsr_al = (reg & IIC_DVFS_BIT_ICSR_AL) == IIC_DVFS_BIT_ICSR_AL;
+	icsr_tack = (reg & IIC_DVFS_BIT_ICSR_TACK) == IIC_DVFS_BIT_ICSR_TACK;
+
+	if (icsr_al == 0 && icsr_tack == 0)
+		return DVFS_PROCESS;
+
+	if (icsr_al) {
+		reg = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_AL;
+		mmio_write_8(IIC_DVFS_REG_ICSR, reg);
+
+		if (*state == DVFS_SET_SLAVE)
+			mmio_write_8(IIC_DVFS_REG_ICDR, IIC_DVFS_SET_DUMMY);
+
+		do {
+			reg = mmio_read_8(IIC_DVFS_REG_ICSR) &
+			    IIC_DVFS_BIT_ICSR_WAIT;
+		} while (reg == 0);
+
+		mmio_write_8(IIC_DVFS_REG_ICCR, stop);
+
+		reg = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+		mmio_write_8(IIC_DVFS_REG_ICSR, reg);
+
+		i = 0;
+		do {
+			reg = mmio_read_8(IIC_DVFS_REG_ICSR) &
+			    IIC_DVFS_BIT_ICSR_BUSY;
+			if (reg == 0)
+				break;
+
+			if (i++ > IIC_DVFS_SET_BUSY_LOOP)
+				panic();
+
+		} while (1);
+
+		mmio_write_8(IIC_DVFS_REG_ICCR, 0x00U);
+
+		(*err)++;
+		if (*err > DVFS_RETRY_MAX)
+			return DVFS_ERROR;
+
+		*state = DVFS_START;
+
+		return DVFS_PROCESS;
+
+	}
+
+	/* icsr_tack */
+	mmio_write_8(IIC_DVFS_REG_ICCR, stop);
+
+	reg = mmio_read_8(IIC_DVFS_REG_ICIC);
+	reg &= ~(IIC_DVFS_BIT_ICIC_WAITE | IIC_DVFS_BIT_ICIC_DTEE);
+	mmio_write_8(IIC_DVFS_REG_ICIC, reg);
+
+	reg = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_TACK;
+	mmio_write_8(IIC_DVFS_REG_ICSR, reg);
+
+	i = 0;
+	while ((mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_BUSY) != 0) {
+		if (i++ > IIC_DVFS_SET_BUSY_LOOP)
+			panic();
+	}
+
+	mmio_write_8(IIC_DVFS_REG_ICCR, 0);
+	(*err)++;
+
+	if (*err > DVFS_RETRY_MAX)
+		return DVFS_ERROR;
+
+	*state = DVFS_START;
+
+	return DVFS_PROCESS;
+}
+
+IIC_DVFS_FUNC(start, DVFS_STATE_T * state)
+{
+	uint8_t iccl = IIC_DVFS_SET_ICCL_EXTAL_TYPE_E;
+	uint8_t icch = IIC_DVFS_SET_ICCH_EXTAL_TYPE_E;
+	int32_t result = DVFS_PROCESS;
+	uint32_t reg, lsi_product;
+	uint8_t mode;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICCR) | IIC_DVFS_BIT_ICCR_ENABLE;
+	mmio_write_8(IIC_DVFS_REG_ICCR, mode);
+
+	lsi_product = mmio_read_32(RCAR_PRR) & RCAR_PRODUCT_MASK;
+	if (lsi_product == RCAR_PRODUCT_E3)
+		goto start;
+
+	reg = mmio_read_32(RCAR_MODEMR) & CHECK_MD13_MD14;
+	switch (reg) {
+	case MD14_MD13_TYPE_0:
+		iccl = IIC_DVFS_SET_ICCL_EXTAL_TYPE_0;
+		icch = IIC_DVFS_SET_ICCH_EXTAL_TYPE_0;
+		break;
+	case MD14_MD13_TYPE_1:
+		iccl = IIC_DVFS_SET_ICCL_EXTAL_TYPE_1;
+		icch = IIC_DVFS_SET_ICCH_EXTAL_TYPE_1;
+		break;
+	case MD14_MD13_TYPE_2:
+		iccl = IIC_DVFS_SET_ICCL_EXTAL_TYPE_2;
+		icch = IIC_DVFS_SET_ICCH_EXTAL_TYPE_2;
+		break;
+	default:
+		iccl = IIC_DVFS_SET_ICCL_EXTAL_TYPE_3;
+		icch = IIC_DVFS_SET_ICCH_EXTAL_TYPE_3;
+		break;
+	}
+start:
+	mmio_write_8(IIC_DVFS_REG_ICCL, iccl);
+	mmio_write_8(IIC_DVFS_REG_ICCH, icch);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICIC)
+	    | IIC_DVFS_BIT_ICIC_TACKE
+	    | IIC_DVFS_BIT_ICIC_WAITE | IIC_DVFS_BIT_ICIC_DTEE;
+
+	mmio_write_8(IIC_DVFS_REG_ICIC, mode);
+	mmio_write_8(IIC_DVFS_REG_ICCR, IIC_DVFS_SET_ICCR_START);
+
+	*state = DVFS_SET_SLAVE;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(set_slave, DVFS_STATE_T * state, uint32_t *err, uint8_t slave)
+{
+	uint8_t mode;
+	int32_t result;
+	uint8_t address;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_DTE;
+	if (mode != IIC_DVFS_BIT_ICSR_DTE)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICIC) & ~IIC_DVFS_BIT_ICIC_DTEE;
+	mmio_write_8(IIC_DVFS_REG_ICIC, mode);
+
+	address = slave << 1;
+	mmio_write_8(IIC_DVFS_REG_ICDR, address);
+
+	*state = DVFS_WRITE_ADDR;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(write_addr, DVFS_STATE_T *state, uint32_t *err, uint8_t reg_addr)
+{
+	uint8_t mode;
+	int32_t result;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICDR, reg_addr);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	*state = DVFS_WRITE_DATA;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(write_data, DVFS_STATE_T *state, uint32_t *err, uint8_t reg_data)
+{
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICDR, reg_data);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	*state = DVFS_STOP;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(stop, DVFS_STATE_T *state, uint32_t *err)
+{
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICCR, IIC_DVFS_SET_ICCR_STOP);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	*state = DVFS_DONE;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(done, void)
+{
+	uint32_t i;
+
+	for (i = 0; i < IIC_DVFS_SET_BUSY_LOOP; i++) {
+		if (mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_BUSY)
+			continue;
+		goto done;
+	}
+
+	panic();
+done:
+	mmio_write_8(IIC_DVFS_REG_ICCR, 0);
+
+	return DVFS_COMPLETE;
+}
+
+IIC_DVFS_FUNC(write_reg_addr_read, DVFS_STATE_T *state, uint32_t *err,
+	uint8_t reg_addr)
+{
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICDR, reg_addr);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	*state = DVFS_RETRANSMIT;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(retransmit, DVFS_STATE_T *state, uint32_t *err)
+{
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICCR, IIC_DVFS_SET_ICCR_RETRANSMISSION);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICIC) | IIC_DVFS_BIT_ICIC_DTEE;
+	mmio_write_8(IIC_DVFS_REG_ICIC, mode);
+
+	*state = DVFS_SET_SLAVE_READ;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(set_slave_read, DVFS_STATE_T *state, uint32_t *err,
+		uint8_t slave)
+{
+	uint8_t address;
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_DTE;
+	if (mode != IIC_DVFS_BIT_ICSR_DTE)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICIC) & ~IIC_DVFS_BIT_ICIC_DTEE;
+	mmio_write_8(IIC_DVFS_REG_ICIC, mode);
+
+	address = ((uint8_t) (slave << 1) + DVFS_READ_MODE);
+	mmio_write_8(IIC_DVFS_REG_ICDR, address);
+
+	*state = DVFS_CHANGE_SEND_TO_RECIEVE;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(change_send_to_recieve, DVFS_STATE_T *state, uint32_t *err)
+{
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_WRITE_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICCR, IIC_DVFS_SET_ICCR_CHANGE);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	*state = DVFS_STOP_READ;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(stop_read, DVFS_STATE_T *state, uint32_t *err)
+{
+	int32_t result;
+	uint8_t mode;
+
+	result = dvfs_check_error(state, err, DVFS_READ_MODE);
+	if (result == DVFS_ERROR)
+		return result;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_WAIT;
+	if (mode != IIC_DVFS_BIT_ICSR_WAIT)
+		return result;
+
+	mmio_write_8(IIC_DVFS_REG_ICCR, IIC_DVFS_SET_ICCR_STOP_READ);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & ~IIC_DVFS_BIT_ICSR_WAIT;
+	mmio_write_8(IIC_DVFS_REG_ICSR, mode);
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICIC) | IIC_DVFS_BIT_ICIC_DTEE;
+	mmio_write_8(IIC_DVFS_REG_ICIC, mode);
+
+	*state = DVFS_READ;
+
+	return result;
+}
+
+IIC_DVFS_FUNC(read, DVFS_STATE_T *state, uint8_t *reg_data)
+{
+	uint8_t mode;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICSR) & IIC_DVFS_BIT_ICSR_DTE;
+	if (mode != IIC_DVFS_BIT_ICSR_DTE)
+		return DVFS_PROCESS;
+
+	mode = mmio_read_8(IIC_DVFS_REG_ICIC) & ~IIC_DVFS_BIT_ICIC_DTEE;
+	mmio_write_8(IIC_DVFS_REG_ICIC, mode);
+
+	*reg_data = mmio_read_8(IIC_DVFS_REG_ICDR);
+	*state = DVFS_DONE;
+
+	return DVFS_PROCESS;
+}
+
+RCAR_DVFS_API(send, uint8_t slave, uint8_t reg_addr, uint8_t reg_data)
+{
+	DVFS_STATE_T state = DVFS_START;
+	int32_t result = DVFS_PROCESS;
+	uint32_t err = 0;
+
+	mstpcr_write(SCMSTPCR9, CPG_MSTPSR9, CPG_BIT_SMSTPCR9_DVFS);
+	mmio_write_8(IIC_DVFS_REG_ICCR, 0);
+again:
+	switch (state) {
+	case DVFS_START:
+		result = dvfs_start(&state);
+		break;
+	case DVFS_SET_SLAVE:
+		result = dvfs_set_slave(&state, &err, slave);
+		break;
+	case DVFS_WRITE_ADDR:
+		result = dvfs_write_addr(&state, &err, reg_addr);
+		break;
+	case DVFS_WRITE_DATA:
+		result = dvfs_write_data(&state, &err, reg_data);
+		break;
+	case DVFS_STOP:
+		result = dvfs_stop(&state, &err);
+		break;
+	case DVFS_DONE:
+		result = dvfs_done();
+		break;
+	default:
+		panic();
+		break;
+	}
+
+	if (result == DVFS_PROCESS)
+		goto again;
+
+	return result;
+}
+
+RCAR_DVFS_API(receive, uint8_t slave, uint8_t reg, uint8_t *data)
+{
+	DVFS_STATE_T state = DVFS_START;
+	int32_t result = DVFS_PROCESS;
+	uint32_t err = 0;
+
+	mstpcr_write(SCMSTPCR9, CPG_MSTPSR9, CPG_BIT_SMSTPCR9_DVFS);
+	mmio_write_8(IIC_DVFS_REG_ICCR, 0);
+again:
+	switch (state) {
+	case DVFS_START:
+		result = dvfs_start(&state);
+		break;
+	case DVFS_SET_SLAVE:
+		result = dvfs_set_slave(&state, &err, slave);
+		break;
+	case DVFS_WRITE_ADDR:
+		result = dvfs_write_reg_addr_read(&state, &err, reg);
+		break;
+	case DVFS_RETRANSMIT:
+		result = dvfs_retransmit(&state, &err);
+		break;
+	case DVFS_SET_SLAVE_READ:
+		result = dvfs_set_slave_read(&state, &err, slave);
+		break;
+	case DVFS_CHANGE_SEND_TO_RECIEVE:
+		result = dvfs_change_send_to_recieve(&state, &err);
+		break;
+	case DVFS_STOP_READ:
+		result = dvfs_stop_read(&state, &err);
+		break;
+	case DVFS_READ:
+		result = dvfs_read(&state, data);
+		break;
+	case DVFS_DONE:
+		result = dvfs_done();
+		break;
+	default:
+		panic();
+		break;
+	}
+
+	if (result == DVFS_PROCESS)
+		goto again;
+
+	return result;
+}