diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 0f079be..5b5a978 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -78,4 +78,14 @@ config ARM_EXYNOS4_BUS_DEVFREQ
 	  To operate with optimal voltages, ASV support is required
 	  (CONFIG_EXYNOS_ASV).
 
+config ARM_EXYNOS5_BUS_DEVFREQ
+	bool "ARM Exynos5250 Bus DEVFREQ Driver"
+	depends on SOC_EXYNOS5250 && EXYNOS5250_PPMU
+	select ARCH_HAS_OPP
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	help
+	  This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
+	  It reads PPMU counters of memory controllers and adjusts the
+	  operating frequencies and voltages with OPP support.
+
 endif # PM_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 8c46423..1771276 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 
 # DEVFREQ Drivers
 obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos4_bus.o
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos5_bus.o
diff --git a/drivers/devfreq/exynos5_bus.c b/drivers/devfreq/exynos5_bus.c
new file mode 100644
index 0000000..ad442a4
--- /dev/null
+++ b/drivers/devfreq/exynos5_bus.c
@@ -0,0 +1,469 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS5 INT clock frequency scaling support using DEVFREQ framework
+ * Based on work done by Jonghwan Choi <jhbird.choi@samsung.com>
+ * Support for only EXYNOS5250 is present.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <linux/opp.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/pm_qos.h>
+#include <linux/regulator/consumer.h>
+
+#include <mach/exynos_ppmu.h>
+#include <mach/exynos5_ppmu.h>
+#include "governor.h"
+
+#define MAX_SAFEVOLT			1100000 /* 1.10V */
+/* Assume that the bus is saturated if the utilization is 25% */
+#define INT_BUS_SATURATION_RATIO	25
+#define EXYNOS5_BUS_INT_POLL_TIME	msecs_to_jiffies(100)
+
+enum int_level_idx {
+	LV_0,
+	LV_1,
+	LV_2,
+	LV_3,
+	LV_4,
+	_LV_END
+};
+
+struct busfreq_data_int {
+	struct device *dev;
+	struct devfreq *devfreq;
+	bool disabled;
+	struct regulator *vdd_int;
+	unsigned long curr_freq;
+	struct notifier_block pm_notifier;
+	struct mutex lock;
+	struct pm_qos_request int_req;
+	struct clk *int_clk;
+	struct exynos5_ppmu_handle *ppmu;
+	struct delayed_work work;
+	int busy;
+};
+
+struct int_bus_opp_table {
+	unsigned int idx;
+	unsigned long clk;
+	unsigned long volt;
+};
+
+static struct int_bus_opp_table exynos5_int_opp_table[] = {
+	{LV_0, 266000, 1025000},
+	{LV_1, 200000, 1025000},
+	{LV_2, 160000, 1025000},
+	{LV_3, 133000, 1025000},
+	{LV_4, 100000, 1025000},
+	{0, 0, 0},
+};
+
+static int exynos5_int_setvolt(struct busfreq_data_int *data,
+		unsigned long volt)
+{
+	return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT);
+}
+
+static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq,
+			      u32 flags)
+{
+	int err = 0;
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+	struct opp *opp;
+	unsigned long old_freq, freq;
+	unsigned long volt;
+
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, _freq, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "%s: Invalid OPP.\n", __func__);
+		return PTR_ERR(opp);
+	}
+
+	freq = opp_get_freq(opp);
+	volt = opp_get_voltage(opp);
+	rcu_read_unlock();
+
+	old_freq = data->curr_freq;
+
+	if (old_freq == freq)
+		return 0;
+
+	dev_dbg(dev, "targetting %lukHz %luuV\n", freq, volt);
+
+	mutex_lock(&data->lock);
+
+	if (data->disabled)
+		goto out;
+
+	if (freq > exynos5_int_opp_table[_LV_END - 1].clk)
+		pm_qos_update_request(&data->int_req,
+				data->busy * old_freq * 16 / 100000);
+	else
+		pm_qos_update_request(&data->int_req, -1);
+
+	if (old_freq < freq)
+		err = exynos5_int_setvolt(data, volt);
+	if (err)
+		goto out;
+
+	err = clk_set_rate(data->int_clk, freq * 1000);
+
+	if (err)
+		goto out;
+
+	if (old_freq > freq)
+		err = exynos5_int_setvolt(data, volt);
+	if (err)
+		goto out;
+
+	data->curr_freq = freq;
+out:
+	mutex_unlock(&data->lock);
+	return err;
+}
+
+static int exynos5_int_get_dev_status(struct device *dev,
+				      struct devfreq_dev_status *stat)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	stat->current_frequency = data->curr_freq;
+	stat->busy_time = data->busy;
+	stat->total_time = 100;
+
+	return 0;
+}
+
+static void exynos5_int_poll_start(struct busfreq_data_int *data)
+{
+	schedule_delayed_work(&data->work, EXYNOS5_BUS_INT_POLL_TIME);
+}
+
+static void exynos5_int_poll_stop(struct busfreq_data_int *data)
+{
+	cancel_delayed_work_sync(&data->work);
+}
+
+static void exynos5_int_poll(struct work_struct *work)
+{
+	struct delayed_work *dwork;
+	struct busfreq_data_int *data;
+	int ret;
+
+	dwork = to_delayed_work(work);
+	data = container_of(dwork, struct busfreq_data_int, work);
+
+	ret = exynos5_ppmu_get_busy(data->ppmu, PPMU_SET_RIGHT);
+
+	if (ret >= 0) {
+		data->busy = ret;
+		mutex_lock(&data->devfreq->lock);
+		update_devfreq(data->devfreq);
+		mutex_unlock(&data->devfreq->lock);
+	}
+
+	schedule_delayed_work(&data->work, EXYNOS5_BUS_INT_POLL_TIME);
+}
+
+static void exynos5_int_exit(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	devfreq_unregister_opp_notifier(dev, data->devfreq);
+}
+
+static struct devfreq_dev_profile exynos5_devfreq_int_profile = {
+	.initial_freq		= 160000,
+	.polling_ms		= 0,
+	.target			= exynos5_busfreq_int_target,
+	.get_dev_status		= exynos5_int_get_dev_status,
+	.exit			= exynos5_int_exit,
+};
+
+static int exynos5250_init_int_tables(struct busfreq_data_int *data)
+{
+	int i, err = 0;
+
+	for (i = LV_0; i < _LV_END; i++) {
+		err = opp_add(data->dev, exynos5_int_opp_table[i].clk,
+				exynos5_int_opp_table[i].volt);
+		if (err) {
+			dev_err(data->dev, "Cannot add opp entries.\n");
+			return err;
+		}
+	}
+
+	return 0;
+}
+static struct devfreq_simple_ondemand_data exynos5_int_ondemand_data = {
+	.downdifferential = 2,
+	.upthreshold = INT_BUS_SATURATION_RATIO,
+};
+
+static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this,
+		unsigned long event, void *ptr)
+{
+	struct busfreq_data_int *data = container_of(this,
+					struct busfreq_data_int, pm_notifier);
+	struct opp *opp;
+	unsigned long maxfreq = ULONG_MAX;
+	unsigned long freq;
+	unsigned long volt;
+	int err = 0;
+
+	switch (event) {
+	case PM_SUSPEND_PREPARE:
+		/* Set Fastest and Deactivate DVFS */
+		mutex_lock(&data->lock);
+
+		data->disabled = true;
+
+		rcu_read_lock();
+		opp = opp_find_freq_floor(data->dev, &maxfreq);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			err = PTR_ERR(opp);
+			goto unlock;
+		}
+		freq = opp_get_freq(opp);
+		volt = opp_get_voltage(opp);
+		rcu_read_unlock();
+
+		err = exynos5_int_setvolt(data, volt);
+		if (err)
+			goto unlock;
+
+		err = clk_set_rate(data->int_clk, freq * 1000);
+
+		if (err)
+			goto unlock;
+
+		data->curr_freq = freq;
+unlock:
+		mutex_unlock(&data->lock);
+		if (err)
+			return NOTIFY_BAD;
+		return NOTIFY_OK;
+	case PM_POST_RESTORE:
+	case PM_POST_SUSPEND:
+		/* Reactivate */
+		mutex_lock(&data->lock);
+		data->disabled = false;
+		mutex_unlock(&data->lock);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static __devinit int exynos5_busfreq_int_probe(struct platform_device *pdev)
+{
+	struct busfreq_data_int *data;
+	struct opp *opp;
+	struct device *dev = &pdev->dev;
+	unsigned long initial_freq;
+	unsigned long initial_volt;
+	int err = 0;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int),
+				GFP_KERNEL);
+	if (data == NULL) {
+		dev_err(dev, "Cannot allocate memory.\n");
+		return -ENOMEM;
+	}
+
+	data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event;
+	data->dev = dev;
+	mutex_init(&data->lock);
+
+	err = exynos5250_init_int_tables(data);
+	if (err)
+		goto err_regulator;
+
+	data->vdd_int = regulator_get(dev, "vdd_int");
+	if (IS_ERR(data->vdd_int)) {
+		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
+		err = PTR_ERR(data->vdd_int);
+		goto err_regulator;
+	}
+
+	data->int_clk = clk_get(dev, "int_clk");
+	if (IS_ERR(data->int_clk)) {
+		dev_err(dev, "Cannot get clock \"int_clk\"\n");
+		err = PTR_ERR(data->int_clk);
+		goto err_clock;
+	}
+
+	rcu_read_lock();
+	opp = opp_find_freq_floor(dev,
+			&exynos5_devfreq_int_profile.initial_freq);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "Invalid initial frequency %lu kHz.\n",
+		       exynos5_devfreq_int_profile.initial_freq);
+		err = PTR_ERR(opp);
+		goto err_opp_add;
+	}
+	initial_freq = opp_get_freq(opp);
+	initial_volt = opp_get_voltage(opp);
+	rcu_read_unlock();
+	data->curr_freq = initial_freq;
+
+	err = clk_set_rate(data->int_clk, initial_freq * 1000);
+	if (err) {
+		dev_err(dev, "Failed to set initial frequency\n");
+		goto err_opp_add;
+	}
+
+	err = exynos5_int_setvolt(data, initial_volt);
+	if (err)
+		goto err_opp_add;
+
+	platform_set_drvdata(pdev, data);
+
+	data->ppmu = exynos5_ppmu_get();
+	if (!data->ppmu)
+		goto err_ppmu_get;
+
+	INIT_DELAYED_WORK(&data->work, exynos5_int_poll);
+	exynos5_int_poll_start(data);
+
+	data->devfreq = devfreq_add_device(dev, &exynos5_devfreq_int_profile,
+					   "simple_ondemand",
+					   &exynos5_int_ondemand_data);
+
+	if (IS_ERR(data->devfreq)) {
+		err = PTR_ERR(data->devfreq);
+		goto err_devfreq_add;
+	}
+
+	devfreq_register_opp_notifier(dev, data->devfreq);
+
+	err = register_pm_notifier(&data->pm_notifier);
+	if (err) {
+		dev_err(dev, "Failed to setup pm notifier\n");
+		goto err_devfreq_add;
+	}
+
+	/* TODO: Add a new QOS class for int/mif bus */
+	pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1);
+
+	return 0;
+
+err_devfreq_add:
+	devfreq_remove_device(data->devfreq);
+	exynos5_int_poll_stop(data);
+err_ppmu_get:
+	platform_set_drvdata(pdev, NULL);
+err_opp_add:
+	clk_put(data->int_clk);
+err_clock:
+	regulator_put(data->vdd_int);
+err_regulator:
+	return err;
+}
+
+static __devexit int exynos5_busfreq_int_remove(struct platform_device *pdev)
+{
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	pm_qos_remove_request(&data->int_req);
+	unregister_pm_notifier(&data->pm_notifier);
+	devfreq_remove_device(data->devfreq);
+	regulator_put(data->vdd_int);
+	clk_put(data->int_clk);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int exynos5_busfreq_int_suspend(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	exynos5_int_poll_stop(data);
+	return 0;
+}
+
+static int exynos5_busfreq_int_resume(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	exynos5_int_poll_start(data);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(exynos5_busfreq_int_pm, exynos5_busfreq_int_suspend,
+		exynos5_busfreq_int_resume);
+
+/* platform device pointer for exynos5 devfreq device. */
+static struct platform_device *exynos5_devfreq_pdev;
+
+static struct platform_driver exynos5_busfreq_int_driver = {
+	.probe		= exynos5_busfreq_int_probe,
+	.remove		= __devexit_p(exynos5_busfreq_int_remove),
+	.driver		= {
+		.name		= "exynos5-bus-int",
+		.owner		= THIS_MODULE,
+		.pm		= &exynos5_busfreq_int_pm,
+	},
+};
+
+static int __init exynos5_busfreq_int_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&exynos5_busfreq_int_driver);
+	if (ret < 0)
+		goto out;
+
+	exynos5_devfreq_pdev =
+		platform_device_register_simple("exynos5-bus-int", -1, NULL, 0);
+	if (IS_ERR_OR_NULL(exynos5_devfreq_pdev)) {
+		ret = PTR_ERR(exynos5_devfreq_pdev);
+		goto out1;
+	}
+
+	return 0;
+out1:
+	platform_driver_unregister(&exynos5_busfreq_int_driver);
+out:
+	return ret;
+}
+late_initcall(exynos5_busfreq_int_init);
+
+static void __exit exynos5_busfreq_int_exit(void)
+{
+	platform_device_unregister(exynos5_devfreq_pdev);
+	platform_driver_unregister(&exynos5_busfreq_int_driver);
+}
+module_exit(exynos5_busfreq_int_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework");
