Initial import

20 files changed, 5399 insertions, 0 deletions

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
new file mode 100644
index 000000000..64281bb2f
--- /dev/null
+++ b/drivers/devfreq/Kconfig
@@ -0,0 +1,103 @@
+menuconfig PM_DEVFREQ
+	bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
+	select SRCU
+	help
+	  A device may have a list of frequencies and voltages available.
+	  devfreq, a generic DVFS framework can be registered for a device
+	  in order to let the governor provided to devfreq choose an
+	  operating frequency based on the device driver's policy.
+
+	  Each device may have its own governor and policy. Devfreq can
+	  reevaluate the device state periodically and/or based on the
+	  notification to "nb", a notifier block, of devfreq.
+
+	  Like some CPUs with CPUfreq, a device may have multiple clocks.
+	  However, because the clock frequencies of a single device are
+	  determined by the single device's state, an instance of devfreq
+	  is attached to a single device and returns a "representative"
+	  clock frequency of the device, which is also attached
+	  to a device by 1-to-1. The device registering devfreq takes the
+	  responsibility to "interpret" the representative frequency and
+	  to set its every clock accordingly with the "target" callback
+	  given to devfreq.
+
+	  When OPP is used with the devfreq device, it is recommended to
+	  register devfreq's nb to the OPP's notifier head.  If OPP is
+	  used with the devfreq device, you may use OPP helper
+	  functions defined in devfreq.h.
+
+if PM_DEVFREQ
+
+comment "DEVFREQ Governors"
+
+config DEVFREQ_GOV_SIMPLE_ONDEMAND
+	tristate "Simple Ondemand"
+	help
+	  Chooses frequency based on the recent load on the device. Works
+	  similar as ONDEMAND governor of CPUFREQ does. A device with
+	  Simple-Ondemand should be able to provide busy/total counter
+	  values that imply the usage rate. A device may provide tuned
+	  values to the governor with data field at devfreq_add_device().
+
+config DEVFREQ_GOV_PERFORMANCE
+	tristate "Performance"
+	help
+	  Sets the frequency at the maximum available frequency.
+	  This governor always returns UINT_MAX as frequency so that
+	  the DEVFREQ framework returns the highest frequency available
+	  at any time.
+
+config DEVFREQ_GOV_POWERSAVE
+	tristate "Powersave"
+	help
+	  Sets the frequency at the minimum available frequency.
+	  This governor always returns 0 as frequency so that
+	  the DEVFREQ framework returns the lowest frequency available
+	  at any time.
+
+config DEVFREQ_GOV_USERSPACE
+	tristate "Userspace"
+	help
+	  Sets the frequency at the user specified one.
+	  This governor returns the user configured frequency if there
+	  has been an input to /sys/devices/.../power/devfreq_set_freq.
+	  Otherwise, the governor does not change the frequnecy
+	  given at the initialization.
+
+comment "DEVFREQ Drivers"
+
+config ARM_EXYNOS4_BUS_DEVFREQ
+	bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
+	depends on (CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	select PM_OPP
+	help
+	  This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
+	  and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
+	  It reads PPMU counters of memory controllers and adjusts
+	  the operating frequencies and voltages with OPP support.
+	  This does not yet operate with optimal voltages.
+
+config ARM_EXYNOS5_BUS_DEVFREQ
+	tristate "ARM Exynos5250 Bus DEVFREQ Driver"
+	depends on SOC_EXYNOS5250
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	select PM_OPP
+	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.
+
+config ARM_TEGRA_DEVFREQ
+       tristate "Tegra DEVFREQ Driver"
+       depends on ARCH_TEGRA_124_SOC
+       select DEVFREQ_GOV_SIMPLE_ONDEMAND
+       select PM_OPP
+       help
+         This adds the DEVFREQ driver for the Tegra family of SoCs.
+         It reads ACTMON counters of memory controllers and adjusts the
+         operating frequencies and voltages with OPP support.
+
+source "drivers/devfreq/event/Kconfig"
+
+endif # PM_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
new file mode 100644
index 000000000..5134f9ee9
--- /dev/null
+++ b/drivers/devfreq/Makefile
@@ -0,0 +1,14 @@
+obj-$(CONFIG_PM_DEVFREQ)	+= devfreq.o
+obj-$(CONFIG_PM_DEVFREQ_EVENT)	+= devfreq-event.o
+obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)	+= governor_simpleondemand.o
+obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE)	+= governor_performance.o
+obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
+obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
+
+# DEVFREQ Drivers
+obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/
+obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra-devfreq.o
+
+# DEVFREQ Event Drivers
+obj-$(CONFIG_PM_DEVFREQ_EVENT)		+= event/
diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
new file mode 100644
index 000000000..f304a0289
--- /dev/null
+++ b/drivers/devfreq/devfreq-event.c
@@ -0,0 +1,494 @@
+/*
+ * devfreq-event: a framework to provide raw data and events of devfreq devices
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Author: Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * 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.
+ *
+ * This driver is based on drivers/devfreq/devfreq.c.
+ */
+
+#include <linux/devfreq-event.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/of.h>
+
+static struct class *devfreq_event_class;
+
+/* The list of all devfreq event list */
+static LIST_HEAD(devfreq_event_list);
+static DEFINE_MUTEX(devfreq_event_list_lock);
+
+#define to_devfreq_event(DEV) container_of(DEV, struct devfreq_event_dev, dev)
+
+/**
+ * devfreq_event_enable_edev() - Enable the devfreq-event dev and increase
+ *				 the enable_count of devfreq-event dev.
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function increase the enable_count and enable the
+ * devfreq-event device. The devfreq-event device should be enabled before
+ * using it by devfreq device.
+ */
+int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
+{
+	int ret = 0;
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	mutex_lock(&edev->lock);
+	if (edev->desc->ops && edev->desc->ops->enable
+			&& edev->enable_count == 0) {
+		ret = edev->desc->ops->enable(edev);
+		if (ret < 0)
+			goto err;
+	}
+	edev->enable_count++;
+err:
+	mutex_unlock(&edev->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_enable_edev);
+
+/**
+ * devfreq_event_disable_edev() - Disable the devfreq-event dev and decrease
+ *				  the enable_count of the devfreq-event dev.
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function decrease the enable_count and disable the
+ * devfreq-event device. After the devfreq-event device is disabled,
+ * devfreq device can't use the devfreq-event device for get/set/reset
+ * operations.
+ */
+int devfreq_event_disable_edev(struct devfreq_event_dev *edev)
+{
+	int ret = 0;
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	mutex_lock(&edev->lock);
+	if (edev->enable_count <= 0) {
+		dev_warn(&edev->dev, "unbalanced enable_count\n");
+		ret = -EIO;
+		goto err;
+	}
+
+	if (edev->desc->ops && edev->desc->ops->disable
+			&& edev->enable_count == 1) {
+		ret = edev->desc->ops->disable(edev);
+		if (ret < 0)
+			goto err;
+	}
+	edev->enable_count--;
+err:
+	mutex_unlock(&edev->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_disable_edev);
+
+/**
+ * devfreq_event_is_enabled() - Check whether devfreq-event dev is enabled or
+ *				not.
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function check whether devfreq-event dev is enabled or not.
+ * If return true, the devfreq-event dev is enabeld. If return false, the
+ * devfreq-event dev is disabled.
+ */
+bool devfreq_event_is_enabled(struct devfreq_event_dev *edev)
+{
+	bool enabled = false;
+
+	if (!edev || !edev->desc)
+		return enabled;
+
+	mutex_lock(&edev->lock);
+
+	if (edev->enable_count > 0)
+		enabled = true;
+
+	mutex_unlock(&edev->lock);
+
+	return enabled;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_is_enabled);
+
+/**
+ * devfreq_event_set_event() - Set event to devfreq-event dev to start.
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function set the event to the devfreq-event device to start
+ * for getting the event data which could be various event type.
+ */
+int devfreq_event_set_event(struct devfreq_event_dev *edev)
+{
+	int ret;
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	if (!edev->desc->ops || !edev->desc->ops->set_event)
+		return -EINVAL;
+
+	if (!devfreq_event_is_enabled(edev))
+		return -EPERM;
+
+	mutex_lock(&edev->lock);
+	ret = edev->desc->ops->set_event(edev);
+	mutex_unlock(&edev->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_set_event);
+
+/**
+ * devfreq_event_get_event() - Get {load|total}_count from devfreq-event dev.
+ * @edev	: the devfreq-event device
+ * @edata	: the calculated data of devfreq-event device
+ *
+ * Note that this function get the calculated event data from devfreq-event dev
+ * after stoping the progress of whole sequence of devfreq-event dev.
+ */
+int devfreq_event_get_event(struct devfreq_event_dev *edev,
+			    struct devfreq_event_data *edata)
+{
+	int ret;
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	if (!edev->desc->ops || !edev->desc->ops->get_event)
+		return -EINVAL;
+
+	if (!devfreq_event_is_enabled(edev))
+		return -EINVAL;
+
+	edata->total_count = edata->load_count = 0;
+
+	mutex_lock(&edev->lock);
+	ret = edev->desc->ops->get_event(edev, edata);
+	if (ret < 0)
+		edata->total_count = edata->load_count = 0;
+	mutex_unlock(&edev->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_get_event);
+
+/**
+ * devfreq_event_reset_event() - Reset all opeations of devfreq-event dev.
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function stop all operations of devfreq-event dev and reset
+ * the current event data to make the devfreq-event device into initial state.
+ */
+int devfreq_event_reset_event(struct devfreq_event_dev *edev)
+{
+	int ret = 0;
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	if (!devfreq_event_is_enabled(edev))
+		return -EPERM;
+
+	mutex_lock(&edev->lock);
+	if (edev->desc->ops && edev->desc->ops->reset)
+		ret = edev->desc->ops->reset(edev);
+	mutex_unlock(&edev->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_reset_event);
+
+/**
+ * devfreq_event_get_edev_by_phandle() - Get the devfreq-event dev from
+ *					 devicetree.
+ * @dev		: the pointer to the given device
+ * @index	: the index into list of devfreq-event device
+ *
+ * Note that this function return the pointer of devfreq-event device.
+ */
+struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev,
+						      int index)
+{
+	struct device_node *node;
+	struct devfreq_event_dev *edev;
+
+	if (!dev->of_node) {
+		dev_err(dev, "device does not have a device node entry\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	node = of_parse_phandle(dev->of_node, "devfreq-events", index);
+	if (!node) {
+		dev_err(dev, "failed to get phandle in %s node\n",
+			dev->of_node->full_name);
+		return ERR_PTR(-ENODEV);
+	}
+
+	mutex_lock(&devfreq_event_list_lock);
+	list_for_each_entry(edev, &devfreq_event_list, node) {
+		if (!strcmp(edev->desc->name, node->name))
+			goto out;
+	}
+	edev = NULL;
+out:
+	mutex_unlock(&devfreq_event_list_lock);
+
+	if (!edev) {
+		dev_err(dev, "unable to get devfreq-event device : %s\n",
+			node->name);
+		of_node_put(node);
+		return ERR_PTR(-ENODEV);
+	}
+
+	of_node_put(node);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_get_edev_by_phandle);
+
+/**
+ * devfreq_event_get_edev_count() - Get the count of devfreq-event dev
+ * @dev		: the pointer to the given device
+ *
+ * Note that this function return the count of devfreq-event devices.
+ */
+int devfreq_event_get_edev_count(struct device *dev)
+{
+	int count;
+
+	if (!dev->of_node) {
+		dev_err(dev, "device does not have a device node entry\n");
+		return -EINVAL;
+	}
+
+	count = of_property_count_elems_of_size(dev->of_node, "devfreq-events",
+						sizeof(u32));
+	if (count < 0 ) {
+		dev_err(dev,
+			"failed to get the count of devfreq-event in %s node\n",
+			dev->of_node->full_name);
+		return count;
+	}
+
+	return count;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_get_edev_count);
+
+static void devfreq_event_release_edev(struct device *dev)
+{
+	struct devfreq_event_dev *edev = to_devfreq_event(dev);
+
+	kfree(edev);
+}
+
+/**
+ * devfreq_event_add_edev() - Add new devfreq-event device.
+ * @dev		: the device owning the devfreq-event device being created
+ * @desc	: the devfreq-event device's decriptor which include essential
+ *		  data for devfreq-event device.
+ *
+ * Note that this function add new devfreq-event device to devfreq-event class
+ * list and register the device of the devfreq-event device.
+ */
+struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
+						struct devfreq_event_desc *desc)
+{
+	struct devfreq_event_dev *edev;
+	static atomic_t event_no = ATOMIC_INIT(0);
+	int ret;
+
+	if (!dev || !desc)
+		return ERR_PTR(-EINVAL);
+
+	if (!desc->name || !desc->ops)
+		return ERR_PTR(-EINVAL);
+
+	if (!desc->ops->set_event || !desc->ops->get_event)
+		return ERR_PTR(-EINVAL);
+
+	edev = kzalloc(sizeof(struct devfreq_event_dev), GFP_KERNEL);
+	if (!edev)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&edev->lock);
+	edev->desc = desc;
+	edev->enable_count = 0;
+	edev->dev.parent = dev;
+	edev->dev.class = devfreq_event_class;
+	edev->dev.release = devfreq_event_release_edev;
+
+	dev_set_name(&edev->dev, "event.%d", atomic_inc_return(&event_no) - 1);
+	ret = device_register(&edev->dev);
+	if (ret < 0) {
+		put_device(&edev->dev);
+		return ERR_PTR(ret);
+	}
+	dev_set_drvdata(&edev->dev, edev);
+
+	INIT_LIST_HEAD(&edev->node);
+
+	mutex_lock(&devfreq_event_list_lock);
+	list_add(&edev->node, &devfreq_event_list);
+	mutex_unlock(&devfreq_event_list_lock);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_add_edev);
+
+/**
+ * devfreq_event_remove_edev() - Remove the devfreq-event device registered.
+ * @dev		: the devfreq-event device
+ *
+ * Note that this function remove the registered devfreq-event device.
+ */
+int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
+{
+	if (!edev)
+		return -EINVAL;
+
+	WARN_ON(edev->enable_count);
+
+	mutex_lock(&devfreq_event_list_lock);
+	list_del(&edev->node);
+	mutex_unlock(&devfreq_event_list_lock);
+
+	device_unregister(&edev->dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devfreq_event_remove_edev);
+
+static int devm_devfreq_event_match(struct device *dev, void *res, void *data)
+{
+	struct devfreq_event_dev **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+static void devm_devfreq_event_release(struct device *dev, void *res)
+{
+	devfreq_event_remove_edev(*(struct devfreq_event_dev **)res);
+}
+
+/**
+ * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @desc	: the devfreq-event device's decriptor which include essential
+ *		  data for devfreq-event device.
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management and simplify the free operation
+ * for memory of devfreq-event device.
+ */
+struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+						struct devfreq_event_desc *desc)
+{
+	struct devfreq_event_dev **ptr, *edev;
+
+	ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	edev = devfreq_event_add_edev(dev, desc);
+	if (IS_ERR(edev)) {
+		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*ptr = edev;
+	devres_add(dev, ptr);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev);
+
+/**
+ * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management.
+ */
+void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_event_release,
+			       devm_devfreq_event_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev);
+
+/*
+ * Device attributes for devfreq-event class.
+ */
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct devfreq_event_dev *edev = to_devfreq_event(dev);
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	return sprintf(buf, "%s\n", edev->desc->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static ssize_t enable_count_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct devfreq_event_dev *edev = to_devfreq_event(dev);
+
+	if (!edev || !edev->desc)
+		return -EINVAL;
+
+	return sprintf(buf, "%d\n", edev->enable_count);
+}
+static DEVICE_ATTR_RO(enable_count);
+
+static struct attribute *devfreq_event_attrs[] = {
+	&dev_attr_name.attr,
+	&dev_attr_enable_count.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(devfreq_event);
+
+static int __init devfreq_event_init(void)
+{
+	devfreq_event_class = class_create(THIS_MODULE, "devfreq-event");
+	if (IS_ERR(devfreq_event_class)) {
+		pr_err("%s: couldn't create class\n", __FILE__);
+		return PTR_ERR(devfreq_event_class);
+	}
+
+	devfreq_event_class->dev_groups = devfreq_event_groups;
+
+	return 0;
+}
+subsys_initcall(devfreq_event_init);
+
+static void __exit devfreq_event_exit(void)
+{
+	class_destroy(devfreq_event_class);
+}
+module_exit(devfreq_event_exit);
+
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_DESCRIPTION("DEVFREQ-Event class support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
new file mode 100644
index 000000000..ca1b362d7
--- /dev/null
+++ b/drivers/devfreq/devfreq.c
@@ -0,0 +1,1224 @@
+/*
+ * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
+ *	    for Non-CPU Devices.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/pm_opp.h>
+#include <linux/devfreq.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/printk.h>
+#include <linux/hrtimer.h>
+#include "governor.h"
+
+static struct class *devfreq_class;
+
+/*
+ * devfreq core provides delayed work based load monitoring helper
+ * functions. Governors can use these or can implement their own
+ * monitoring mechanism.
+ */
+static struct workqueue_struct *devfreq_wq;
+
+/* The list of all device-devfreq governors */
+static LIST_HEAD(devfreq_governor_list);
+/* The list of all device-devfreq */
+static LIST_HEAD(devfreq_list);
+static DEFINE_MUTEX(devfreq_list_lock);
+
+/**
+ * find_device_devfreq() - find devfreq struct using device pointer
+ * @dev:	device pointer used to lookup device devfreq.
+ *
+ * Search the list of device devfreqs and return the matched device's
+ * devfreq info. devfreq_list_lock should be held by the caller.
+ */
+static struct devfreq *find_device_devfreq(struct device *dev)
+{
+	struct devfreq *tmp_devfreq;
+
+	if (unlikely(IS_ERR_OR_NULL(dev))) {
+		pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+	WARN(!mutex_is_locked(&devfreq_list_lock),
+	     "devfreq_list_lock must be locked.");
+
+	list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
+		if (tmp_devfreq->dev.parent == dev)
+			return tmp_devfreq;
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+/**
+ * devfreq_get_freq_level() - Lookup freq_table for the frequency
+ * @devfreq:	the devfreq instance
+ * @freq:	the target frequency
+ */
+static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
+{
+	int lev;
+
+	for (lev = 0; lev < devfreq->profile->max_state; lev++)
+		if (freq == devfreq->profile->freq_table[lev])
+			return lev;
+
+	return -EINVAL;
+}
+
+/**
+ * devfreq_update_status() - Update statistics of devfreq behavior
+ * @devfreq:	the devfreq instance
+ * @freq:	the update target frequency
+ */
+static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
+{
+	int lev, prev_lev, ret = 0;
+	unsigned long cur_time;
+
+	cur_time = jiffies;
+
+	prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
+	if (prev_lev < 0) {
+		ret = prev_lev;
+		goto out;
+	}
+
+	devfreq->time_in_state[prev_lev] +=
+			 cur_time - devfreq->last_stat_updated;
+
+	lev = devfreq_get_freq_level(devfreq, freq);
+	if (lev < 0) {
+		ret = lev;
+		goto out;
+	}
+
+	if (lev != prev_lev) {
+		devfreq->trans_table[(prev_lev *
+				devfreq->profile->max_state) + lev]++;
+		devfreq->total_trans++;
+	}
+
+out:
+	devfreq->last_stat_updated = cur_time;
+	return ret;
+}
+
+/**
+ * find_devfreq_governor() - find devfreq governor from name
+ * @name:	name of the governor
+ *
+ * Search the list of devfreq governors and return the matched
+ * governor's pointer. devfreq_list_lock should be held by the caller.
+ */
+static struct devfreq_governor *find_devfreq_governor(const char *name)
+{
+	struct devfreq_governor *tmp_governor;
+
+	if (unlikely(IS_ERR_OR_NULL(name))) {
+		pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+	WARN(!mutex_is_locked(&devfreq_list_lock),
+	     "devfreq_list_lock must be locked.");
+
+	list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
+		if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
+			return tmp_governor;
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+/* Load monitoring helper functions for governors use */
+
+/**
+ * update_devfreq() - Reevaluate the device and configure frequency.
+ * @devfreq:	the devfreq instance.
+ *
+ * Note: Lock devfreq->lock before calling update_devfreq
+ *	 This function is exported for governors.
+ */
+int update_devfreq(struct devfreq *devfreq)
+{
+	unsigned long freq;
+	int err = 0;
+	u32 flags = 0;
+
+	if (!mutex_is_locked(&devfreq->lock)) {
+		WARN(true, "devfreq->lock must be locked by the caller.\n");
+		return -EINVAL;
+	}
+
+	if (!devfreq->governor)
+		return -EINVAL;
+
+	/* Reevaluate the proper frequency */
+	err = devfreq->governor->get_target_freq(devfreq, &freq);
+	if (err)
+		return err;
+
+	/*
+	 * Adjust the freuqency with user freq and QoS.
+	 *
+	 * List from the highest proiority
+	 * max_freq (probably called by thermal when it's too hot)
+	 * min_freq
+	 */
+
+	if (devfreq->min_freq && freq < devfreq->min_freq) {
+		freq = devfreq->min_freq;
+		flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
+	}
+	if (devfreq->max_freq && freq > devfreq->max_freq) {
+		freq = devfreq->max_freq;
+		flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
+	}
+
+	err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
+	if (err)
+		return err;
+
+	if (devfreq->profile->freq_table)
+		if (devfreq_update_status(devfreq, freq))
+			dev_err(&devfreq->dev,
+				"Couldn't update frequency transition information.\n");
+
+	devfreq->previous_freq = freq;
+	return err;
+}
+EXPORT_SYMBOL(update_devfreq);
+
+/**
+ * devfreq_monitor() - Periodically poll devfreq objects.
+ * @work:	the work struct used to run devfreq_monitor periodically.
+ *
+ */
+static void devfreq_monitor(struct work_struct *work)
+{
+	int err;
+	struct devfreq *devfreq = container_of(work,
+					struct devfreq, work.work);
+
+	mutex_lock(&devfreq->lock);
+	err = update_devfreq(devfreq);
+	if (err)
+		dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
+
+	queue_delayed_work(devfreq_wq, &devfreq->work,
+				msecs_to_jiffies(devfreq->profile->polling_ms));
+	mutex_unlock(&devfreq->lock);
+}
+
+/**
+ * devfreq_monitor_start() - Start load monitoring of devfreq instance
+ * @devfreq:	the devfreq instance.
+ *
+ * Helper function for starting devfreq device load monitoing. By
+ * default delayed work based monitoring is supported. Function
+ * to be called from governor in response to DEVFREQ_GOV_START
+ * event when device is added to devfreq framework.
+ */
+void devfreq_monitor_start(struct devfreq *devfreq)
+{
+	INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
+	if (devfreq->profile->polling_ms)
+		queue_delayed_work(devfreq_wq, &devfreq->work,
+			msecs_to_jiffies(devfreq->profile->polling_ms));
+}
+EXPORT_SYMBOL(devfreq_monitor_start);
+
+/**
+ * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
+ * @devfreq:	the devfreq instance.
+ *
+ * Helper function to stop devfreq device load monitoing. Function
+ * to be called from governor in response to DEVFREQ_GOV_STOP
+ * event when device is removed from devfreq framework.
+ */
+void devfreq_monitor_stop(struct devfreq *devfreq)
+{
+	cancel_delayed_work_sync(&devfreq->work);
+}
+EXPORT_SYMBOL(devfreq_monitor_stop);
+
+/**
+ * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
+ * @devfreq:	the devfreq instance.
+ *
+ * Helper function to suspend devfreq device load monitoing. Function
+ * to be called from governor in response to DEVFREQ_GOV_SUSPEND
+ * event or when polling interval is set to zero.
+ *
+ * Note: Though this function is same as devfreq_monitor_stop(),
+ * intentionally kept separate to provide hooks for collecting
+ * transition statistics.
+ */
+void devfreq_monitor_suspend(struct devfreq *devfreq)
+{
+	mutex_lock(&devfreq->lock);
+	if (devfreq->stop_polling) {
+		mutex_unlock(&devfreq->lock);
+		return;
+	}
+
+	devfreq_update_status(devfreq, devfreq->previous_freq);
+	devfreq->stop_polling = true;
+	mutex_unlock(&devfreq->lock);
+	cancel_delayed_work_sync(&devfreq->work);
+}
+EXPORT_SYMBOL(devfreq_monitor_suspend);
+
+/**
+ * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
+ * @devfreq:    the devfreq instance.
+ *
+ * Helper function to resume devfreq device load monitoing. Function
+ * to be called from governor in response to DEVFREQ_GOV_RESUME
+ * event or when polling interval is set to non-zero.
+ */
+void devfreq_monitor_resume(struct devfreq *devfreq)
+{
+	unsigned long freq;
+
+	mutex_lock(&devfreq->lock);
+	if (!devfreq->stop_polling)
+		goto out;
+
+	if (!delayed_work_pending(&devfreq->work) &&
+			devfreq->profile->polling_ms)
+		queue_delayed_work(devfreq_wq, &devfreq->work,
+			msecs_to_jiffies(devfreq->profile->polling_ms));
+
+	devfreq->last_stat_updated = jiffies;
+	devfreq->stop_polling = false;
+
+	if (devfreq->profile->get_cur_freq &&
+		!devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
+		devfreq->previous_freq = freq;
+
+out:
+	mutex_unlock(&devfreq->lock);
+}
+EXPORT_SYMBOL(devfreq_monitor_resume);
+
+/**
+ * devfreq_interval_update() - Update device devfreq monitoring interval
+ * @devfreq:    the devfreq instance.
+ * @delay:      new polling interval to be set.
+ *
+ * Helper function to set new load monitoring polling interval. Function
+ * to be called from governor in response to DEVFREQ_GOV_INTERVAL event.
+ */
+void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay)
+{
+	unsigned int cur_delay = devfreq->profile->polling_ms;
+	unsigned int new_delay = *delay;
+
+	mutex_lock(&devfreq->lock);
+	devfreq->profile->polling_ms = new_delay;
+
+	if (devfreq->stop_polling)
+		goto out;
+
+	/* if new delay is zero, stop polling */
+	if (!new_delay) {
+		mutex_unlock(&devfreq->lock);
+		cancel_delayed_work_sync(&devfreq->work);
+		return;
+	}
+
+	/* if current delay is zero, start polling with new delay */
+	if (!cur_delay) {
+		queue_delayed_work(devfreq_wq, &devfreq->work,
+			msecs_to_jiffies(devfreq->profile->polling_ms));
+		goto out;
+	}
+
+	/* if current delay is greater than new delay, restart polling */
+	if (cur_delay > new_delay) {
+		mutex_unlock(&devfreq->lock);
+		cancel_delayed_work_sync(&devfreq->work);
+		mutex_lock(&devfreq->lock);
+		if (!devfreq->stop_polling)
+			queue_delayed_work(devfreq_wq, &devfreq->work,
+			      msecs_to_jiffies(devfreq->profile->polling_ms));
+	}
+out:
+	mutex_unlock(&devfreq->lock);
+}
+EXPORT_SYMBOL(devfreq_interval_update);
+
+/**
+ * devfreq_notifier_call() - Notify that the device frequency requirements
+ *			   has been changed out of devfreq framework.
+ * @nb:		the notifier_block (supposed to be devfreq->nb)
+ * @type:	not used
+ * @devp:	not used
+ *
+ * Called by a notifier that uses devfreq->nb.
+ */
+static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
+				 void *devp)
+{
+	struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
+	int ret;
+
+	mutex_lock(&devfreq->lock);
+	ret = update_devfreq(devfreq);
+	mutex_unlock(&devfreq->lock);
+
+	return ret;
+}
+
+/**
+ * _remove_devfreq() - Remove devfreq from the list and release its resources.
+ * @devfreq:	the devfreq struct
+ */
+static void _remove_devfreq(struct devfreq *devfreq)
+{
+	mutex_lock(&devfreq_list_lock);
+	if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
+		mutex_unlock(&devfreq_list_lock);
+		dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
+		return;
+	}
+	list_del(&devfreq->node);
+	mutex_unlock(&devfreq_list_lock);
+
+	if (devfreq->governor)
+		devfreq->governor->event_handler(devfreq,
+						 DEVFREQ_GOV_STOP, NULL);
+
+	if (devfreq->profile->exit)
+		devfreq->profile->exit(devfreq->dev.parent);
+
+	mutex_destroy(&devfreq->lock);
+	kfree(devfreq);
+}
+
+/**
+ * devfreq_dev_release() - Callback for struct device to release the device.
+ * @dev:	the devfreq device
+ *
+ * This calls _remove_devfreq() if _remove_devfreq() is not called.
+ */
+static void devfreq_dev_release(struct device *dev)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+
+	_remove_devfreq(devfreq);
+}
+
+/**
+ * devfreq_add_device() - Add devfreq feature to the device
+ * @dev:	the device to add devfreq feature.
+ * @profile:	device-specific profile to run devfreq.
+ * @governor_name:	name of the policy to choose frequency.
+ * @data:	private data for the governor. The devfreq framework does not
+ *		touch this value.
+ */
+struct devfreq *devfreq_add_device(struct device *dev,
+				   struct devfreq_dev_profile *profile,
+				   const char *governor_name,
+				   void *data)
+{
+	struct devfreq *devfreq;
+	struct devfreq_governor *governor;
+	int err = 0;
+
+	if (!dev || !profile || !governor_name) {
+		dev_err(dev, "%s: Invalid parameters.\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	mutex_lock(&devfreq_list_lock);
+	devfreq = find_device_devfreq(dev);
+	mutex_unlock(&devfreq_list_lock);
+	if (!IS_ERR(devfreq)) {
+		dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__);
+		err = -EINVAL;
+		goto err_out;
+	}
+
+	devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
+	if (!devfreq) {
+		dev_err(dev, "%s: Unable to create devfreq for the device\n",
+			__func__);
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	mutex_init(&devfreq->lock);
+	mutex_lock(&devfreq->lock);
+	devfreq->dev.parent = dev;
+	devfreq->dev.class = devfreq_class;
+	devfreq->dev.release = devfreq_dev_release;
+	devfreq->profile = profile;
+	strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
+	devfreq->previous_freq = profile->initial_freq;
+	devfreq->data = data;
+	devfreq->nb.notifier_call = devfreq_notifier_call;
+
+	devfreq->trans_table =	devm_kzalloc(dev, sizeof(unsigned int) *
+						devfreq->profile->max_state *
+						devfreq->profile->max_state,
+						GFP_KERNEL);
+	devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) *
+						devfreq->profile->max_state,
+						GFP_KERNEL);
+	devfreq->last_stat_updated = jiffies;
+
+	dev_set_name(&devfreq->dev, "%s", dev_name(dev));
+	err = device_register(&devfreq->dev);
+	if (err) {
+		put_device(&devfreq->dev);
+		mutex_unlock(&devfreq->lock);
+		goto err_dev;
+	}
+
+	mutex_unlock(&devfreq->lock);
+
+	mutex_lock(&devfreq_list_lock);
+	list_add(&devfreq->node, &devfreq_list);
+
+	governor = find_devfreq_governor(devfreq->governor_name);
+	if (!IS_ERR(governor))
+		devfreq->governor = governor;
+	if (devfreq->governor)
+		err = devfreq->governor->event_handler(devfreq,
+					DEVFREQ_GOV_START, NULL);
+	mutex_unlock(&devfreq_list_lock);
+	if (err) {
+		dev_err(dev, "%s: Unable to start governor for the device\n",
+			__func__);
+		goto err_init;
+	}
+
+	return devfreq;
+
+err_init:
+	list_del(&devfreq->node);
+	device_unregister(&devfreq->dev);
+err_dev:
+	kfree(devfreq);
+err_out:
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(devfreq_add_device);
+
+/**
+ * devfreq_remove_device() - Remove devfreq feature from a device.
+ * @devfreq:	the devfreq instance to be removed
+ *
+ * The opposite of devfreq_add_device().
+ */
+int devfreq_remove_device(struct devfreq *devfreq)
+{
+	if (!devfreq)
+		return -EINVAL;
+
+	device_unregister(&devfreq->dev);
+	put_device(&devfreq->dev);
+
+	return 0;
+}
+EXPORT_SYMBOL(devfreq_remove_device);
+
+static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
+{
+	struct devfreq **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+static void devm_devfreq_dev_release(struct device *dev, void *res)
+{
+	devfreq_remove_device(*(struct devfreq **)res);
+}
+
+/**
+ * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
+ * @dev:	the device to add devfreq feature.
+ * @profile:	device-specific profile to run devfreq.
+ * @governor_name:	name of the policy to choose frequency.
+ * @data:	private data for the governor. The devfreq framework does not
+ *		touch this value.
+ *
+ * This function manages automatically the memory of devfreq device using device
+ * resource management and simplify the free operation for memory of devfreq
+ * device.
+ */
+struct devfreq *devm_devfreq_add_device(struct device *dev,
+					struct devfreq_dev_profile *profile,
+					const char *governor_name,
+					void *data)
+{
+	struct devfreq **ptr, *devfreq;
+
+	ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	devfreq = devfreq_add_device(dev, profile, governor_name, data);
+	if (IS_ERR(devfreq)) {
+		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*ptr = devfreq;
+	devres_add(dev, ptr);
+
+	return devfreq;
+}
+EXPORT_SYMBOL(devm_devfreq_add_device);
+
+/**
+ * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
+ * @dev:	the device to add devfreq feature.
+ * @devfreq:	the devfreq instance to be removed
+ */
+void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_dev_release,
+			       devm_devfreq_dev_match, devfreq));
+}
+EXPORT_SYMBOL(devm_devfreq_remove_device);
+
+/**
+ * devfreq_suspend_device() - Suspend devfreq of a device.
+ * @devfreq: the devfreq instance to be suspended
+ *
+ * This function is intended to be called by the pm callbacks
+ * (e.g., runtime_suspend, suspend) of the device driver that
+ * holds the devfreq.
+ */
+int devfreq_suspend_device(struct devfreq *devfreq)
+{
+	if (!devfreq)
+		return -EINVAL;
+
+	if (!devfreq->governor)
+		return 0;
+
+	return devfreq->governor->event_handler(devfreq,
+				DEVFREQ_GOV_SUSPEND, NULL);
+}
+EXPORT_SYMBOL(devfreq_suspend_device);
+
+/**
+ * devfreq_resume_device() - Resume devfreq of a device.
+ * @devfreq: the devfreq instance to be resumed
+ *
+ * This function is intended to be called by the pm callbacks
+ * (e.g., runtime_resume, resume) of the device driver that
+ * holds the devfreq.
+ */
+int devfreq_resume_device(struct devfreq *devfreq)
+{
+	if (!devfreq)
+		return -EINVAL;
+
+	if (!devfreq->governor)
+		return 0;
+
+	return devfreq->governor->event_handler(devfreq,
+				DEVFREQ_GOV_RESUME, NULL);
+}
+EXPORT_SYMBOL(devfreq_resume_device);
+
+/**
+ * devfreq_add_governor() - Add devfreq governor
+ * @governor:	the devfreq governor to be added
+ */
+int devfreq_add_governor(struct devfreq_governor *governor)
+{
+	struct devfreq_governor *g;
+	struct devfreq *devfreq;
+	int err = 0;
+
+	if (!governor) {
+		pr_err("%s: Invalid parameters.\n", __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&devfreq_list_lock);
+	g = find_devfreq_governor(governor->name);
+	if (!IS_ERR(g)) {
+		pr_err("%s: governor %s already registered\n", __func__,
+		       g->name);
+		err = -EINVAL;
+		goto err_out;
+	}
+
+	list_add(&governor->node, &devfreq_governor_list);
+
+	list_for_each_entry(devfreq, &devfreq_list, node) {
+		int ret = 0;
+		struct device *dev = devfreq->dev.parent;
+
+		if (!strncmp(devfreq->governor_name, governor->name,
+			     DEVFREQ_NAME_LEN)) {
+			/* The following should never occur */
+			if (devfreq->governor) {
+				dev_warn(dev,
+					 "%s: Governor %s already present\n",
+					 __func__, devfreq->governor->name);
+				ret = devfreq->governor->event_handler(devfreq,
+							DEVFREQ_GOV_STOP, NULL);
+				if (ret) {
+					dev_warn(dev,
+						 "%s: Governor %s stop = %d\n",
+						 __func__,
+						 devfreq->governor->name, ret);
+				}
+				/* Fall through */
+			}
+			devfreq->governor = governor;
+			ret = devfreq->governor->event_handler(devfreq,
+						DEVFREQ_GOV_START, NULL);
+			if (ret) {
+				dev_warn(dev, "%s: Governor %s start=%d\n",
+					 __func__, devfreq->governor->name,
+					 ret);
+			}
+		}
+	}
+
+err_out:
+	mutex_unlock(&devfreq_list_lock);
+
+	return err;
+}
+EXPORT_SYMBOL(devfreq_add_governor);
+
+/**
+ * devfreq_remove_device() - Remove devfreq feature from a device.
+ * @governor:	the devfreq governor to be removed
+ */
+int devfreq_remove_governor(struct devfreq_governor *governor)
+{
+	struct devfreq_governor *g;
+	struct devfreq *devfreq;
+	int err = 0;
+
+	if (!governor) {
+		pr_err("%s: Invalid parameters.\n", __func__);
+		return -EINVAL;
+	}
+
+	mutex_lock(&devfreq_list_lock);
+	g = find_devfreq_governor(governor->name);
+	if (IS_ERR(g)) {
+		pr_err("%s: governor %s not registered\n", __func__,
+		       governor->name);
+		err = PTR_ERR(g);
+		goto err_out;
+	}
+	list_for_each_entry(devfreq, &devfreq_list, node) {
+		int ret;
+		struct device *dev = devfreq->dev.parent;
+
+		if (!strncmp(devfreq->governor_name, governor->name,
+			     DEVFREQ_NAME_LEN)) {
+			/* we should have a devfreq governor! */
+			if (!devfreq->governor) {
+				dev_warn(dev, "%s: Governor %s NOT present\n",
+					 __func__, governor->name);
+				continue;
+				/* Fall through */
+			}
+			ret = devfreq->governor->event_handler(devfreq,
+						DEVFREQ_GOV_STOP, NULL);
+			if (ret) {
+				dev_warn(dev, "%s: Governor %s stop=%d\n",
+					 __func__, devfreq->governor->name,
+					 ret);
+			}
+			devfreq->governor = NULL;
+		}
+	}
+
+	list_del(&governor->node);
+err_out:
+	mutex_unlock(&devfreq_list_lock);
+
+	return err;
+}
+EXPORT_SYMBOL(devfreq_remove_governor);
+
+static ssize_t governor_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	if (!to_devfreq(dev)->governor)
+		return -EINVAL;
+
+	return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
+}
+
+static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	int ret;
+	char str_governor[DEVFREQ_NAME_LEN + 1];
+	struct devfreq_governor *governor;
+
+	ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
+	if (ret != 1)
+		return -EINVAL;
+
+	mutex_lock(&devfreq_list_lock);
+	governor = find_devfreq_governor(str_governor);
+	if (IS_ERR(governor)) {
+		ret = PTR_ERR(governor);
+		goto out;
+	}
+	if (df->governor == governor)
+		goto out;
+
+	if (df->governor) {
+		ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
+		if (ret) {
+			dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
+				 __func__, df->governor->name, ret);
+			goto out;
+		}
+	}
+	df->governor = governor;
+	strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
+	ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
+	if (ret)
+		dev_warn(dev, "%s: Governor %s not started(%d)\n",
+			 __func__, df->governor->name, ret);
+out:
+	mutex_unlock(&devfreq_list_lock);
+
+	if (!ret)
+		ret = count;
+	return ret;
+}
+static DEVICE_ATTR_RW(governor);
+
+static ssize_t available_governors_show(struct device *d,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct devfreq_governor *tmp_governor;
+	ssize_t count = 0;
+
+	mutex_lock(&devfreq_list_lock);
+	list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
+		count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+				   "%s ", tmp_governor->name);
+	mutex_unlock(&devfreq_list_lock);
+
+	/* Truncate the trailing space */
+	if (count)
+		count--;
+
+	count += sprintf(&buf[count], "\n");
+
+	return count;
+}
+static DEVICE_ATTR_RO(available_governors);
+
+static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	unsigned long freq;
+	struct devfreq *devfreq = to_devfreq(dev);
+
+	if (devfreq->profile->get_cur_freq &&
+		!devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
+			return sprintf(buf, "%lu\n", freq);
+
+	return sprintf(buf, "%lu\n", devfreq->previous_freq);
+}
+static DEVICE_ATTR_RO(cur_freq);
+
+static ssize_t target_freq_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
+}
+static DEVICE_ATTR_RO(target_freq);
+
+static ssize_t polling_interval_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms);
+}
+
+static ssize_t polling_interval_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	unsigned int value;
+	int ret;
+
+	if (!df->governor)
+		return -EINVAL;
+
+	ret = sscanf(buf, "%u", &value);
+	if (ret != 1)
+		return -EINVAL;
+
+	df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value);
+	ret = count;
+
+	return ret;
+}
+static DEVICE_ATTR_RW(polling_interval);
+
+static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	unsigned long value;
+	int ret;
+	unsigned long max;
+
+	ret = sscanf(buf, "%lu", &value);
+	if (ret != 1)
+		return -EINVAL;
+
+	mutex_lock(&df->lock);
+	max = df->max_freq;
+	if (value && max && value > max) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	df->min_freq = value;
+	update_devfreq(df);
+	ret = count;
+unlock:
+	mutex_unlock(&df->lock);
+	return ret;
+}
+
+static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
+}
+
+static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	unsigned long value;
+	int ret;
+	unsigned long min;
+
+	ret = sscanf(buf, "%lu", &value);
+	if (ret != 1)
+		return -EINVAL;
+
+	mutex_lock(&df->lock);
+	min = df->min_freq;
+	if (value && min && value < min) {
+		ret = -EINVAL;
+		goto unlock;
+	}
+
+	df->max_freq = value;
+	update_devfreq(df);
+	ret = count;
+unlock:
+	mutex_unlock(&df->lock);
+	return ret;
+}
+static DEVICE_ATTR_RW(min_freq);
+
+static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
+}
+static DEVICE_ATTR_RW(max_freq);
+
+static ssize_t available_frequencies_show(struct device *d,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct devfreq *df = to_devfreq(d);
+	struct device *dev = df->dev.parent;
+	struct dev_pm_opp *opp;
+	ssize_t count = 0;
+	unsigned long freq = 0;
+
+	rcu_read_lock();
+	do {
+		opp = dev_pm_opp_find_freq_ceil(dev, &freq);
+		if (IS_ERR(opp))
+			break;
+
+		count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
+				   "%lu ", freq);
+		freq++;
+	} while (1);
+	rcu_read_unlock();
+
+	/* Truncate the trailing space */
+	if (count)
+		count--;
+
+	count += sprintf(&buf[count], "\n");
+
+	return count;
+}
+static DEVICE_ATTR_RO(available_frequencies);
+
+static ssize_t trans_stat_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	ssize_t len;
+	int i, j;
+	unsigned int max_state = devfreq->profile->max_state;
+
+	if (!devfreq->stop_polling &&
+			devfreq_update_status(devfreq, devfreq->previous_freq))
+		return 0;
+
+	len = sprintf(buf, "   From  :   To\n");
+	len += sprintf(buf + len, "         :");
+	for (i = 0; i < max_state; i++)
+		len += sprintf(buf + len, "%8u",
+				devfreq->profile->freq_table[i]);
+
+	len += sprintf(buf + len, "   time(ms)\n");
+
+	for (i = 0; i < max_state; i++) {
+		if (devfreq->profile->freq_table[i]
+					== devfreq->previous_freq) {
+			len += sprintf(buf + len, "*");
+		} else {
+			len += sprintf(buf + len, " ");
+		}
+		len += sprintf(buf + len, "%8u:",
+				devfreq->profile->freq_table[i]);
+		for (j = 0; j < max_state; j++)
+			len += sprintf(buf + len, "%8u",
+				devfreq->trans_table[(i * max_state) + j]);
+		len += sprintf(buf + len, "%10u\n",
+			jiffies_to_msecs(devfreq->time_in_state[i]));
+	}
+
+	len += sprintf(buf + len, "Total transition : %u\n",
+					devfreq->total_trans);
+	return len;
+}
+static DEVICE_ATTR_RO(trans_stat);
+
+static struct attribute *devfreq_attrs[] = {
+	&dev_attr_governor.attr,
+	&dev_attr_available_governors.attr,
+	&dev_attr_cur_freq.attr,
+	&dev_attr_available_frequencies.attr,
+	&dev_attr_target_freq.attr,
+	&dev_attr_polling_interval.attr,
+	&dev_attr_min_freq.attr,
+	&dev_attr_max_freq.attr,
+	&dev_attr_trans_stat.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(devfreq);
+
+static int __init devfreq_init(void)
+{
+	devfreq_class = class_create(THIS_MODULE, "devfreq");
+	if (IS_ERR(devfreq_class)) {
+		pr_err("%s: couldn't create class\n", __FILE__);
+		return PTR_ERR(devfreq_class);
+	}
+
+	devfreq_wq = create_freezable_workqueue("devfreq_wq");
+	if (!devfreq_wq) {
+		class_destroy(devfreq_class);
+		pr_err("%s: couldn't create workqueue\n", __FILE__);
+		return -ENOMEM;
+	}
+	devfreq_class->dev_groups = devfreq_groups;
+
+	return 0;
+}
+subsys_initcall(devfreq_init);
+
+static void __exit devfreq_exit(void)
+{
+	class_destroy(devfreq_class);
+	destroy_workqueue(devfreq_wq);
+}
+module_exit(devfreq_exit);
+
+/*
+ * The followings are helper functions for devfreq user device drivers with
+ * OPP framework.
+ */
+
+/**
+ * devfreq_recommended_opp() - Helper function to get proper OPP for the
+ *			     freq value given to target callback.
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @freq:	The frequency given to target function
+ * @flags:	Flags handed from devfreq framework.
+ *
+ * Locking: This function must be called under rcu_read_lock(). opp is a rcu
+ * protected pointer. The reason for the same is that the opp pointer which is
+ * returned will remain valid for use with opp_get_{voltage, freq} only while
+ * under the locked area. The pointer returned must be used prior to unlocking
+ * with rcu_read_unlock() to maintain the integrity of the pointer.
+ */
+struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
+					   unsigned long *freq,
+					   u32 flags)
+{
+	struct dev_pm_opp *opp;
+
+	if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
+		/* The freq is an upper bound. opp should be lower */
+		opp = dev_pm_opp_find_freq_floor(dev, freq);
+
+		/* If not available, use the closest opp */
+		if (opp == ERR_PTR(-ERANGE))
+			opp = dev_pm_opp_find_freq_ceil(dev, freq);
+	} else {
+		/* The freq is an lower bound. opp should be higher */
+		opp = dev_pm_opp_find_freq_ceil(dev, freq);
+
+		/* If not available, use the closest opp */
+		if (opp == ERR_PTR(-ERANGE))
+			opp = dev_pm_opp_find_freq_floor(dev, freq);
+	}
+
+	return opp;
+}
+EXPORT_SYMBOL(devfreq_recommended_opp);
+
+/**
+ * devfreq_register_opp_notifier() - Helper function to get devfreq notified
+ *				   for any changes in the OPP availability
+ *				   changes
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @devfreq:	The devfreq object.
+ */
+int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
+{
+	struct srcu_notifier_head *nh;
+	int ret = 0;
+
+	rcu_read_lock();
+	nh = dev_pm_opp_get_notifier(dev);
+	if (IS_ERR(nh))
+		ret = PTR_ERR(nh);
+	rcu_read_unlock();
+	if (!ret)
+		ret = srcu_notifier_chain_register(nh, &devfreq->nb);
+
+	return ret;
+}
+EXPORT_SYMBOL(devfreq_register_opp_notifier);
+
+/**
+ * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
+ *				     notified for any changes in the OPP
+ *				     availability changes anymore.
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @devfreq:	The devfreq object.
+ *
+ * At exit() callback of devfreq_dev_profile, this must be included if
+ * devfreq_recommended_opp is used.
+ */
+int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
+{
+	struct srcu_notifier_head *nh;
+	int ret = 0;
+
+	rcu_read_lock();
+	nh = dev_pm_opp_get_notifier(dev);
+	if (IS_ERR(nh))
+		ret = PTR_ERR(nh);
+	rcu_read_unlock();
+	if (!ret)
+		ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
+
+	return ret;
+}
+EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
+
+static void devm_devfreq_opp_release(struct device *dev, void *res)
+{
+	devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
+}
+
+/**
+ * devm_ devfreq_register_opp_notifier()
+ *		- Resource-managed devfreq_register_opp_notifier()
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @devfreq:	The devfreq object.
+ */
+int devm_devfreq_register_opp_notifier(struct device *dev,
+				       struct devfreq *devfreq)
+{
+	struct devfreq **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = devfreq_register_opp_notifier(dev, devfreq);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	*ptr = devfreq;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
+
+/**
+ * devm_devfreq_unregister_opp_notifier()
+ *		- Resource-managed devfreq_unregister_opp_notifier()
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @devfreq:	The devfreq object.
+ */
+void devm_devfreq_unregister_opp_notifier(struct device *dev,
+					 struct devfreq *devfreq)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_opp_release,
+			       devm_devfreq_dev_match, devfreq));
+}
+EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
+
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("devfreq class support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/event/Kconfig b/drivers/devfreq/event/Kconfig
new file mode 100644
index 000000000..a11720aff
--- /dev/null
+++ b/drivers/devfreq/event/Kconfig
@@ -0,0 +1,25 @@
+menuconfig PM_DEVFREQ_EVENT
+	bool "DEVFREQ-Event device Support"
+	help
+	  The devfreq-event device provide the raw data and events which
+	  indicate the current state of devfreq-event device. The provided
+	  data from devfreq-event device is used to monitor the state of
+	  device and determine the suitable size of resource to reduce the
+	  wasted resource.
+
+	  The devfreq-event device can support the various type of events
+	  (e.g., raw data, utilization, latency, bandwidth). The events
+	  may be used by devfreq governor and other subsystem.
+
+if PM_DEVFREQ_EVENT
+
+config DEVFREQ_EVENT_EXYNOS_PPMU
+	bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
+	depends on ARCH_EXYNOS
+	select PM_OPP
+	help
+	  This add the devfreq-event driver for Exynos SoC. It provides PPMU
+	  (Platform Performance Monitoring Unit) counters to estimate the
+	  utilization of each module.
+
+endif # PM_DEVFREQ_EVENT
diff --git a/drivers/devfreq/event/Makefile b/drivers/devfreq/event/Makefile
new file mode 100644
index 000000000..be146ead7
--- /dev/null
+++ b/drivers/devfreq/event/Makefile
@@ -0,0 +1,2 @@
+# Exynos DEVFREQ Event Drivers
+obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_PPMU) += exynos-ppmu.o
diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c
new file mode 100644
index 000000000..7d99d13ba
--- /dev/null
+++ b/drivers/devfreq/event/exynos-ppmu.c
@@ -0,0 +1,374 @@
+/*
+ * exynos_ppmu.c - EXYNOS PPMU (Platform Performance Monitoring Unit) support
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * 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.
+ *
+ * This driver is based on drivers/devfreq/exynos/exynos_ppmu.c
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/suspend.h>
+#include <linux/devfreq-event.h>
+
+#include "exynos-ppmu.h"
+
+struct exynos_ppmu_data {
+	void __iomem *base;
+	struct clk *clk;
+};
+
+struct exynos_ppmu {
+	struct devfreq_event_dev **edev;
+	struct devfreq_event_desc *desc;
+	unsigned int num_events;
+
+	struct device *dev;
+	struct mutex lock;
+
+	struct exynos_ppmu_data ppmu;
+};
+
+#define PPMU_EVENT(name)			\
+	{ "ppmu-event0-"#name, PPMU_PMNCNT0 },	\
+	{ "ppmu-event1-"#name, PPMU_PMNCNT1 },	\
+	{ "ppmu-event2-"#name, PPMU_PMNCNT2 },	\
+	{ "ppmu-event3-"#name, PPMU_PMNCNT3 }
+
+struct __exynos_ppmu_events {
+	char *name;
+	int id;
+} ppmu_events[] = {
+	/* For Exynos3250, Exynos4 and Exynos5260 */
+	PPMU_EVENT(g3d),
+	PPMU_EVENT(fsys),
+
+	/* For Exynos4 SoCs and Exynos3250 */
+	PPMU_EVENT(dmc0),
+	PPMU_EVENT(dmc1),
+	PPMU_EVENT(cpu),
+	PPMU_EVENT(rightbus),
+	PPMU_EVENT(leftbus),
+	PPMU_EVENT(lcd0),
+	PPMU_EVENT(camif),
+
+	/* Only for Exynos3250 and Exynos5260 */
+	PPMU_EVENT(mfc),
+
+	/* Only for Exynos4 SoCs */
+	PPMU_EVENT(mfc-left),
+	PPMU_EVENT(mfc-right),
+
+	/* Only for Exynos5260 SoCs */
+	PPMU_EVENT(drex0-s0),
+	PPMU_EVENT(drex0-s1),
+	PPMU_EVENT(drex1-s0),
+	PPMU_EVENT(drex1-s1),
+	PPMU_EVENT(eagle),
+	PPMU_EVENT(kfc),
+	PPMU_EVENT(isp),
+	PPMU_EVENT(fimc),
+	PPMU_EVENT(gscl),
+	PPMU_EVENT(mscl),
+	PPMU_EVENT(fimd0x),
+	PPMU_EVENT(fimd1x),
+	{ /* sentinel */ },
+};
+
+static int exynos_ppmu_find_ppmu_id(struct devfreq_event_dev *edev)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ppmu_events); i++)
+		if (!strcmp(edev->desc->name, ppmu_events[i].name))
+			return ppmu_events[i].id;
+
+	return -EINVAL;
+}
+
+static int exynos_ppmu_disable(struct devfreq_event_dev *edev)
+{
+	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
+	u32 pmnc;
+
+	/* Disable all counters */
+	__raw_writel(PPMU_CCNT_MASK |
+		     PPMU_PMCNT0_MASK |
+		     PPMU_PMCNT1_MASK |
+		     PPMU_PMCNT2_MASK |
+		     PPMU_PMCNT3_MASK,
+		     info->ppmu.base + PPMU_CNTENC);
+
+	/* Disable PPMU */
+	pmnc = __raw_readl(info->ppmu.base + PPMU_PMNC);
+	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
+	__raw_writel(pmnc, info->ppmu.base + PPMU_PMNC);
+
+	return 0;
+}
+
+static int exynos_ppmu_set_event(struct devfreq_event_dev *edev)
+{
+	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
+	int id = exynos_ppmu_find_ppmu_id(edev);
+	u32 pmnc, cntens;
+
+	if (id < 0)
+		return id;
+
+	/* Enable specific counter */
+	cntens = __raw_readl(info->ppmu.base + PPMU_CNTENS);
+	cntens |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
+	__raw_writel(cntens, info->ppmu.base + PPMU_CNTENS);
+
+	/* Set the event of Read/Write data count  */
+	__raw_writel(PPMU_RO_DATA_CNT | PPMU_WO_DATA_CNT,
+			info->ppmu.base + PPMU_BEVTxSEL(id));
+
+	/* Reset cycle counter/performance counter and enable PPMU */
+	pmnc = __raw_readl(info->ppmu.base + PPMU_PMNC);
+	pmnc &= ~(PPMU_PMNC_ENABLE_MASK
+			| PPMU_PMNC_COUNTER_RESET_MASK
+			| PPMU_PMNC_CC_RESET_MASK);
+	pmnc |= (PPMU_ENABLE << PPMU_PMNC_ENABLE_SHIFT);
+	pmnc |= (PPMU_ENABLE << PPMU_PMNC_COUNTER_RESET_SHIFT);
+	pmnc |= (PPMU_ENABLE << PPMU_PMNC_CC_RESET_SHIFT);
+	__raw_writel(pmnc, info->ppmu.base + PPMU_PMNC);
+
+	return 0;
+}
+
+static int exynos_ppmu_get_event(struct devfreq_event_dev *edev,
+				struct devfreq_event_data *edata)
+{
+	struct exynos_ppmu *info = devfreq_event_get_drvdata(edev);
+	int id = exynos_ppmu_find_ppmu_id(edev);
+	u32 pmnc, cntenc;
+
+	if (id < 0)
+		return -EINVAL;
+
+	/* Disable PPMU */
+	pmnc = __raw_readl(info->ppmu.base + PPMU_PMNC);
+	pmnc &= ~PPMU_PMNC_ENABLE_MASK;
+	__raw_writel(pmnc, info->ppmu.base + PPMU_PMNC);
+
+	/* Read cycle count */
+	edata->total_count = __raw_readl(info->ppmu.base + PPMU_CCNT);
+
+	/* Read performance count */
+	switch (id) {
+	case PPMU_PMNCNT0:
+	case PPMU_PMNCNT1:
+	case PPMU_PMNCNT2:
+		edata->load_count
+			= __raw_readl(info->ppmu.base + PPMU_PMNCT(id));
+		break;
+	case PPMU_PMNCNT3:
+		edata->load_count =
+			((__raw_readl(info->ppmu.base + PPMU_PMCNT3_HIGH) << 8)
+			| __raw_readl(info->ppmu.base + PPMU_PMCNT3_LOW));
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Disable specific counter */
+	cntenc = __raw_readl(info->ppmu.base + PPMU_CNTENC);
+	cntenc |= (PPMU_CCNT_MASK | (PPMU_ENABLE << id));
+	__raw_writel(cntenc, info->ppmu.base + PPMU_CNTENC);
+
+	dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
+					edata->load_count, edata->total_count);
+
+	return 0;
+}
+
+static const struct devfreq_event_ops exynos_ppmu_ops = {
+	.disable = exynos_ppmu_disable,
+	.set_event = exynos_ppmu_set_event,
+	.get_event = exynos_ppmu_get_event,
+};
+
+static int of_get_devfreq_events(struct device_node *np,
+				 struct exynos_ppmu *info)
+{
+	struct devfreq_event_desc *desc;
+	struct device *dev = info->dev;
+	struct device_node *events_np, *node;
+	int i, j, count;
+
+	events_np = of_get_child_by_name(np, "events");
+	if (!events_np) {
+		dev_err(dev,
+			"failed to get child node of devfreq-event devices\n");
+		return -EINVAL;
+	}
+
+	count = of_get_child_count(events_np);
+	desc = devm_kzalloc(dev, sizeof(*desc) * count, GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+	info->num_events = count;
+
+	j = 0;
+	for_each_child_of_node(events_np, node) {
+		for (i = 0; i < ARRAY_SIZE(ppmu_events); i++) {
+			if (!ppmu_events[i].name)
+				continue;
+
+			if (!of_node_cmp(node->name, ppmu_events[i].name))
+				break;
+		}
+
+		if (i == ARRAY_SIZE(ppmu_events)) {
+			dev_warn(dev,
+				"don't know how to configure events : %s\n",
+				node->name);
+			continue;
+		}
+
+		desc[j].ops = &exynos_ppmu_ops;
+		desc[j].driver_data = info;
+
+		of_property_read_string(node, "event-name", &desc[j].name);
+
+		j++;
+
+		of_node_put(node);
+	}
+	info->desc = desc;
+
+	of_node_put(events_np);
+
+	return 0;
+}
+
+static int exynos_ppmu_parse_dt(struct exynos_ppmu *info)
+{
+	struct device *dev = info->dev;
+	struct device_node *np = dev->of_node;
+	int ret = 0;
+
+	if (!np) {
+		dev_err(dev, "failed to find devicetree node\n");
+		return -EINVAL;
+	}
+
+	/* Maps the memory mapped IO to control PPMU register */
+	info->ppmu.base = of_iomap(np, 0);
+	if (IS_ERR_OR_NULL(info->ppmu.base)) {
+		dev_err(dev, "failed to map memory region\n");
+		return -ENOMEM;
+	}
+
+	info->ppmu.clk = devm_clk_get(dev, "ppmu");
+	if (IS_ERR(info->ppmu.clk)) {
+		info->ppmu.clk = NULL;
+		dev_warn(dev, "cannot get PPMU clock\n");
+	}
+
+	ret = of_get_devfreq_events(np, info);
+	if (ret < 0) {
+		dev_err(dev, "failed to parse exynos ppmu dt node\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	iounmap(info->ppmu.base);
+
+	return ret;
+}
+
+static int exynos_ppmu_probe(struct platform_device *pdev)
+{
+	struct exynos_ppmu *info;
+	struct devfreq_event_dev **edev;
+	struct devfreq_event_desc *desc;
+	int i, ret = 0, size;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	mutex_init(&info->lock);
+	info->dev = &pdev->dev;
+
+	/* Parse dt data to get resource */
+	ret = exynos_ppmu_parse_dt(info);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"failed to parse devicetree for resource\n");
+		return ret;
+	}
+	desc = info->desc;
+
+	size = sizeof(struct devfreq_event_dev *) * info->num_events;
+	info->edev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+	if (!info->edev) {
+		dev_err(&pdev->dev,
+			"failed to allocate memory devfreq-event devices\n");
+		return -ENOMEM;
+	}
+	edev = info->edev;
+	platform_set_drvdata(pdev, info);
+
+	for (i = 0; i < info->num_events; i++) {
+		edev[i] = devm_devfreq_event_add_edev(&pdev->dev, &desc[i]);
+		if (IS_ERR(edev[i])) {
+			ret = PTR_ERR(edev[i]);
+			dev_err(&pdev->dev,
+				"failed to add devfreq-event device\n");
+			goto err;
+		}
+	}
+
+	clk_prepare_enable(info->ppmu.clk);
+
+	return 0;
+err:
+	iounmap(info->ppmu.base);
+
+	return ret;
+}
+
+static int exynos_ppmu_remove(struct platform_device *pdev)
+{
+	struct exynos_ppmu *info = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(info->ppmu.clk);
+	iounmap(info->ppmu.base);
+
+	return 0;
+}
+
+static struct of_device_id exynos_ppmu_id_match[] = {
+	{ .compatible = "samsung,exynos-ppmu", },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver exynos_ppmu_driver = {
+	.probe	= exynos_ppmu_probe,
+	.remove	= exynos_ppmu_remove,
+	.driver = {
+		.name	= "exynos-ppmu",
+		.of_match_table = exynos_ppmu_id_match,
+	},
+};
+module_platform_driver(exynos_ppmu_driver);
+
+MODULE_DESCRIPTION("Exynos PPMU(Platform Performance Monitoring Unit) driver");
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/event/exynos-ppmu.h b/drivers/devfreq/event/exynos-ppmu.h
new file mode 100644
index 000000000..4e831d48c
--- /dev/null
+++ b/drivers/devfreq/event/exynos-ppmu.h
@@ -0,0 +1,93 @@
+/*
+ * exynos_ppmu.h - EXYNOS PPMU header file
+ *
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * 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.
+ */
+
+#ifndef __EXYNOS_PPMU_H__
+#define __EXYNOS_PPMU_H__
+
+enum ppmu_state {
+	PPMU_DISABLE = 0,
+	PPMU_ENABLE,
+};
+
+enum ppmu_counter {
+	PPMU_PMNCNT0 = 0,
+	PPMU_PMNCNT1,
+	PPMU_PMNCNT2,
+	PPMU_PMNCNT3,
+
+	PPMU_PMNCNT_MAX,
+};
+
+enum ppmu_event_type {
+	PPMU_RO_BUSY_CYCLE_CNT	= 0x0,
+	PPMU_WO_BUSY_CYCLE_CNT	= 0x1,
+	PPMU_RW_BUSY_CYCLE_CNT	= 0x2,
+	PPMU_RO_REQUEST_CNT	= 0x3,
+	PPMU_WO_REQUEST_CNT	= 0x4,
+	PPMU_RO_DATA_CNT	= 0x5,
+	PPMU_WO_DATA_CNT	= 0x6,
+	PPMU_RO_LATENCY		= 0x12,
+	PPMU_WO_LATENCY		= 0x16,
+};
+
+enum ppmu_reg {
+	/* PPC control register */
+	PPMU_PMNC		= 0x00,
+	PPMU_CNTENS		= 0x10,
+	PPMU_CNTENC		= 0x20,
+	PPMU_INTENS		= 0x30,
+	PPMU_INTENC		= 0x40,
+	PPMU_FLAG		= 0x50,
+
+	/* Cycle Counter and Performance Event Counter Register */
+	PPMU_CCNT		= 0x100,
+	PPMU_PMCNT0		= 0x110,
+	PPMU_PMCNT1		= 0x120,
+	PPMU_PMCNT2		= 0x130,
+	PPMU_PMCNT3_HIGH	= 0x140,
+	PPMU_PMCNT3_LOW		= 0x150,
+
+	/* Bus Event Generator */
+	PPMU_BEVT0SEL		= 0x1000,
+	PPMU_BEVT1SEL		= 0x1100,
+	PPMU_BEVT2SEL		= 0x1200,
+	PPMU_BEVT3SEL		= 0x1300,
+	PPMU_COUNTER_RESET	= 0x1810,
+	PPMU_READ_OVERFLOW_CNT	= 0x1810,
+	PPMU_READ_UNDERFLOW_CNT	= 0x1814,
+	PPMU_WRITE_OVERFLOW_CNT	= 0x1850,
+	PPMU_WRITE_UNDERFLOW_CNT = 0x1854,
+	PPMU_READ_PENDING_CNT	= 0x1880,
+	PPMU_WRITE_PENDING_CNT	= 0x1884
+};
+
+/* PMNC register */
+#define PPMU_PMNC_CC_RESET_SHIFT	2
+#define PPMU_PMNC_COUNTER_RESET_SHIFT	1
+#define PPMU_PMNC_ENABLE_SHIFT		0
+#define PPMU_PMNC_START_MODE_MASK	BIT(16)
+#define PPMU_PMNC_CC_DIVIDER_MASK	BIT(3)
+#define PPMU_PMNC_CC_RESET_MASK		BIT(2)
+#define PPMU_PMNC_COUNTER_RESET_MASK	BIT(1)
+#define PPMU_PMNC_ENABLE_MASK		BIT(0)
+
+/* CNTENS/CNTENC/INTENS/INTENC/FLAG register */
+#define PPMU_CCNT_MASK			BIT(31)
+#define PPMU_PMCNT3_MASK		BIT(3)
+#define PPMU_PMCNT2_MASK		BIT(2)
+#define PPMU_PMCNT1_MASK		BIT(1)
+#define PPMU_PMCNT0_MASK		BIT(0)
+
+/* PPMU_PMNCTx/PPMU_BETxSEL registers */
+#define PPMU_PMNCT(x)			(PPMU_PMCNT0 + (0x10 * x))
+#define PPMU_BEVTxSEL(x)		(PPMU_BEVT0SEL + (0x100 * x))
+
+#endif /* __EXYNOS_PPMU_H__ */
diff --git a/drivers/devfreq/exynos/Makefile b/drivers/devfreq/exynos/Makefile
new file mode 100644
index 000000000..49bc9175f
--- /dev/null
+++ b/drivers/devfreq/exynos/Makefile
@@ -0,0 +1,3 @@
+# Exynos DEVFREQ Drivers
+obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos_ppmu.o exynos4_bus.o
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos_ppmu.o exynos5_bus.o
diff --git a/drivers/devfreq/exynos/exynos4_bus.c b/drivers/devfreq/exynos/exynos4_bus.c
new file mode 100644
index 000000000..da9509205
--- /dev/null
+++ b/drivers/devfreq/exynos/exynos4_bus.c
@@ -0,0 +1,1055 @@
+/* drivers/devfreq/exynos4210_memorybus.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * EXYNOS4 - Memory/Bus clock frequency scaling support in DEVFREQ framework
+ *	This version supports EXYNOS4210 only. This changes bus frequencies
+ *	and vddint voltages. Exynos4412/4212 should be able to be supported
+ *	with minor modifications.
+ *
+ * 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/io.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/suspend.h>
+#include <linux/pm_opp.h>
+#include <linux/devfreq.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+
+#include <mach/map.h>
+
+#include "exynos_ppmu.h"
+#include "exynos4_bus.h"
+
+#define MAX_SAFEVOLT	1200000 /* 1.2V */
+
+enum exynos4_busf_type {
+	TYPE_BUSF_EXYNOS4210,
+	TYPE_BUSF_EXYNOS4x12,
+};
+
+/* Assume that the bus is saturated if the utilization is 40% */
+#define BUS_SATURATION_RATIO	40
+
+enum busclk_level_idx {
+	LV_0 = 0,
+	LV_1,
+	LV_2,
+	LV_3,
+	LV_4,
+	_LV_END
+};
+
+enum exynos_ppmu_idx {
+	PPMU_DMC0,
+	PPMU_DMC1,
+	PPMU_END,
+};
+
+#define EX4210_LV_MAX	LV_2
+#define EX4x12_LV_MAX	LV_4
+#define EX4210_LV_NUM	(LV_2 + 1)
+#define EX4x12_LV_NUM	(LV_4 + 1)
+
+/**
+ * struct busfreq_opp_info - opp information for bus
+ * @rate:	Frequency in hertz
+ * @volt:	Voltage in microvolts corresponding to this OPP
+ */
+struct busfreq_opp_info {
+	unsigned long rate;
+	unsigned long volt;
+};
+
+struct busfreq_data {
+	enum exynos4_busf_type type;
+	struct device *dev;
+	struct devfreq *devfreq;
+	bool disabled;
+	struct regulator *vdd_int;
+	struct regulator *vdd_mif; /* Exynos4412/4212 only */
+	struct busfreq_opp_info curr_oppinfo;
+	struct busfreq_ppmu_data ppmu_data;
+
+	struct notifier_block pm_notifier;
+	struct mutex lock;
+
+	/* Dividers calculated at boot/probe-time */
+	unsigned int dmc_divtable[_LV_END]; /* DMC0 */
+	unsigned int top_divtable[_LV_END];
+};
+
+/* 4210 controls clock of mif and voltage of int */
+static struct bus_opp_table exynos4210_busclk_table[] = {
+	{LV_0, 400000, 1150000},
+	{LV_1, 267000, 1050000},
+	{LV_2, 133000, 1025000},
+	{0, 0, 0},
+};
+
+/*
+ * MIF is the main control knob clock for Exynos4x12 MIF/INT
+ * clock and voltage of both mif/int are controlled.
+ */
+static struct bus_opp_table exynos4x12_mifclk_table[] = {
+	{LV_0, 400000, 1100000},
+	{LV_1, 267000, 1000000},
+	{LV_2, 160000, 950000},
+	{LV_3, 133000, 950000},
+	{LV_4, 100000, 950000},
+	{0, 0, 0},
+};
+
+/*
+ * INT is not the control knob of 4x12. LV_x is not meant to represent
+ * the current performance. (MIF does)
+ */
+static struct bus_opp_table exynos4x12_intclk_table[] = {
+	{LV_0, 200000, 1000000},
+	{LV_1, 160000, 950000},
+	{LV_2, 133000, 925000},
+	{LV_3, 100000, 900000},
+	{0, 0, 0},
+};
+
+/* TODO: asv volt definitions are "__initdata"? */
+/* Some chips have different operating voltages */
+static unsigned int exynos4210_asv_volt[][EX4210_LV_NUM] = {
+	{1150000, 1050000, 1050000},
+	{1125000, 1025000, 1025000},
+	{1100000, 1000000, 1000000},
+	{1075000, 975000, 975000},
+	{1050000, 950000, 950000},
+};
+
+static unsigned int exynos4x12_mif_step_50[][EX4x12_LV_NUM] = {
+	/* 400      267     160     133     100 */
+	{1050000, 950000, 900000, 900000, 900000}, /* ASV0 */
+	{1050000, 950000, 900000, 900000, 900000}, /* ASV1 */
+	{1050000, 950000, 900000, 900000, 900000}, /* ASV2 */
+	{1050000, 900000, 900000, 900000, 900000}, /* ASV3 */
+	{1050000, 900000, 900000, 900000, 850000}, /* ASV4 */
+	{1050000, 900000, 900000, 850000, 850000}, /* ASV5 */
+	{1050000, 900000, 850000, 850000, 850000}, /* ASV6 */
+	{1050000, 900000, 850000, 850000, 850000}, /* ASV7 */
+	{1050000, 900000, 850000, 850000, 850000}, /* ASV8 */
+};
+
+static unsigned int exynos4x12_int_volt[][EX4x12_LV_NUM] = {
+	/* 200    160      133     100 */
+	{1000000, 950000, 925000, 900000}, /* ASV0 */
+	{975000,  925000, 925000, 900000}, /* ASV1 */
+	{950000,  925000, 900000, 875000}, /* ASV2 */
+	{950000,  900000, 900000, 875000}, /* ASV3 */
+	{925000,  875000, 875000, 875000}, /* ASV4 */
+	{900000,  850000, 850000, 850000}, /* ASV5 */
+	{900000,  850000, 850000, 850000}, /* ASV6 */
+	{900000,  850000, 850000, 850000}, /* ASV7 */
+	{900000,  850000, 850000, 850000}, /* ASV8 */
+};
+
+/*** Clock Divider Data for Exynos4210 ***/
+static unsigned int exynos4210_clkdiv_dmc0[][8] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVACP, DIVACP_PCLK, DIVDPHY, DIVDMC, DIVDMCD
+	 *		DIVDMCP, DIVCOPY2, DIVCORE_TIMERS }
+	 */
+
+	/* DMC L0: 400MHz */
+	{ 3, 1, 1, 1, 1, 1, 3, 1 },
+	/* DMC L1: 266.7MHz */
+	{ 4, 1, 1, 2, 1, 1, 3, 1 },
+	/* DMC L2: 133MHz */
+	{ 5, 1, 1, 5, 1, 1, 3, 1 },
+};
+static unsigned int exynos4210_clkdiv_top[][5] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVACLK200, DIVACLK100, DIVACLK160, DIVACLK133, DIVONENAND }
+	 */
+	/* ACLK200 L0: 200MHz */
+	{ 3, 7, 4, 5, 1 },
+	/* ACLK200 L1: 160MHz */
+	{ 4, 7, 5, 6, 1 },
+	/* ACLK200 L2: 133MHz */
+	{ 5, 7, 7, 7, 1 },
+};
+static unsigned int exynos4210_clkdiv_lr_bus[][2] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVGDL/R, DIVGPL/R }
+	 */
+	/* ACLK_GDL/R L1: 200MHz */
+	{ 3, 1 },
+	/* ACLK_GDL/R L2: 160MHz */
+	{ 4, 1 },
+	/* ACLK_GDL/R L3: 133MHz */
+	{ 5, 1 },
+};
+
+/*** Clock Divider Data for Exynos4212/4412 ***/
+static unsigned int exynos4x12_clkdiv_dmc0[][6] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVACP, DIVACP_PCLK, DIVDPHY, DIVDMC, DIVDMCD
+	 *              DIVDMCP}
+	 */
+
+	/* DMC L0: 400MHz */
+	{3, 1, 1, 1, 1, 1},
+	/* DMC L1: 266.7MHz */
+	{4, 1, 1, 2, 1, 1},
+	/* DMC L2: 160MHz */
+	{5, 1, 1, 4, 1, 1},
+	/* DMC L3: 133MHz */
+	{5, 1, 1, 5, 1, 1},
+	/* DMC L4: 100MHz */
+	{7, 1, 1, 7, 1, 1},
+};
+static unsigned int exynos4x12_clkdiv_dmc1[][6] = {
+	/*
+	 * Clock divider value for following
+	 * { G2DACP, DIVC2C, DIVC2C_ACLK }
+	 */
+
+	/* DMC L0: 400MHz */
+	{3, 1, 1},
+	/* DMC L1: 266.7MHz */
+	{4, 2, 1},
+	/* DMC L2: 160MHz */
+	{5, 4, 1},
+	/* DMC L3: 133MHz */
+	{5, 5, 1},
+	/* DMC L4: 100MHz */
+	{7, 7, 1},
+};
+static unsigned int exynos4x12_clkdiv_top[][5] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVACLK266_GPS, DIVACLK100, DIVACLK160,
+		DIVACLK133, DIVONENAND }
+	 */
+
+	/* ACLK_GDL/R L0: 200MHz */
+	{2, 7, 4, 5, 1},
+	/* ACLK_GDL/R L1: 200MHz */
+	{2, 7, 4, 5, 1},
+	/* ACLK_GDL/R L2: 160MHz */
+	{4, 7, 5, 7, 1},
+	/* ACLK_GDL/R L3: 133MHz */
+	{4, 7, 5, 7, 1},
+	/* ACLK_GDL/R L4: 100MHz */
+	{7, 7, 7, 7, 1},
+};
+static unsigned int exynos4x12_clkdiv_lr_bus[][2] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVGDL/R, DIVGPL/R }
+	 */
+
+	/* ACLK_GDL/R L0: 200MHz */
+	{3, 1},
+	/* ACLK_GDL/R L1: 200MHz */
+	{3, 1},
+	/* ACLK_GDL/R L2: 160MHz */
+	{4, 1},
+	/* ACLK_GDL/R L3: 133MHz */
+	{5, 1},
+	/* ACLK_GDL/R L4: 100MHz */
+	{7, 1},
+};
+static unsigned int exynos4x12_clkdiv_sclkip[][3] = {
+	/*
+	 * Clock divider value for following
+	 * { DIVMFC, DIVJPEG, DIVFIMC0~3}
+	 */
+
+	/* SCLK_MFC: 200MHz */
+	{3, 3, 4},
+	/* SCLK_MFC: 200MHz */
+	{3, 3, 4},
+	/* SCLK_MFC: 160MHz */
+	{4, 4, 5},
+	/* SCLK_MFC: 133MHz */
+	{5, 5, 5},
+	/* SCLK_MFC: 100MHz */
+	{7, 7, 7},
+};
+
+
+static int exynos4210_set_busclk(struct busfreq_data *data,
+				 struct busfreq_opp_info *oppi)
+{
+	unsigned int index;
+	unsigned int tmp;
+
+	for (index = LV_0; index < EX4210_LV_NUM; index++)
+		if (oppi->rate == exynos4210_busclk_table[index].clk)
+			break;
+
+	if (index == EX4210_LV_NUM)
+		return -EINVAL;
+
+	/* Change Divider - DMC0 */
+	tmp = data->dmc_divtable[index];
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_DMC0);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_DMC0);
+	} while (tmp & 0x11111111);
+
+	/* Change Divider - TOP */
+	tmp = data->top_divtable[index];
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_TOP);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_TOP);
+	} while (tmp & 0x11111);
+
+	/* Change Divider - LEFTBUS */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_LEFTBUS);
+
+	tmp &= ~(EXYNOS4_CLKDIV_BUS_GDLR_MASK | EXYNOS4_CLKDIV_BUS_GPLR_MASK);
+
+	tmp |= ((exynos4210_clkdiv_lr_bus[index][0] <<
+				EXYNOS4_CLKDIV_BUS_GDLR_SHIFT) |
+		(exynos4210_clkdiv_lr_bus[index][1] <<
+				EXYNOS4_CLKDIV_BUS_GPLR_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_LEFTBUS);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_LEFTBUS);
+	} while (tmp & 0x11);
+
+	/* Change Divider - RIGHTBUS */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_RIGHTBUS);
+
+	tmp &= ~(EXYNOS4_CLKDIV_BUS_GDLR_MASK | EXYNOS4_CLKDIV_BUS_GPLR_MASK);
+
+	tmp |= ((exynos4210_clkdiv_lr_bus[index][0] <<
+				EXYNOS4_CLKDIV_BUS_GDLR_SHIFT) |
+		(exynos4210_clkdiv_lr_bus[index][1] <<
+				EXYNOS4_CLKDIV_BUS_GPLR_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_RIGHTBUS);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_RIGHTBUS);
+	} while (tmp & 0x11);
+
+	return 0;
+}
+
+static int exynos4x12_set_busclk(struct busfreq_data *data,
+				 struct busfreq_opp_info *oppi)
+{
+	unsigned int index;
+	unsigned int tmp;
+
+	for (index = LV_0; index < EX4x12_LV_NUM; index++)
+		if (oppi->rate == exynos4x12_mifclk_table[index].clk)
+			break;
+
+	if (index == EX4x12_LV_NUM)
+		return -EINVAL;
+
+	/* Change Divider - DMC0 */
+	tmp = data->dmc_divtable[index];
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_DMC0);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_DMC0);
+	} while (tmp & 0x11111111);
+
+	/* Change Divider - DMC1 */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_DMC1);
+
+	tmp &= ~(EXYNOS4_CLKDIV_DMC1_G2D_ACP_MASK |
+		EXYNOS4_CLKDIV_DMC1_C2C_MASK |
+		EXYNOS4_CLKDIV_DMC1_C2CACLK_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_dmc1[index][0] <<
+				EXYNOS4_CLKDIV_DMC1_G2D_ACP_SHIFT) |
+		(exynos4x12_clkdiv_dmc1[index][1] <<
+				EXYNOS4_CLKDIV_DMC1_C2C_SHIFT) |
+		(exynos4x12_clkdiv_dmc1[index][2] <<
+				EXYNOS4_CLKDIV_DMC1_C2CACLK_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_DMC1);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_DMC1);
+	} while (tmp & 0x111111);
+
+	/* Change Divider - TOP */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_TOP);
+
+	tmp &= ~(EXYNOS4_CLKDIV_TOP_ACLK266_GPS_MASK |
+		EXYNOS4_CLKDIV_TOP_ACLK100_MASK |
+		EXYNOS4_CLKDIV_TOP_ACLK160_MASK |
+		EXYNOS4_CLKDIV_TOP_ACLK133_MASK |
+		EXYNOS4_CLKDIV_TOP_ONENAND_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_top[index][0] <<
+				EXYNOS4_CLKDIV_TOP_ACLK266_GPS_SHIFT) |
+		(exynos4x12_clkdiv_top[index][1] <<
+				EXYNOS4_CLKDIV_TOP_ACLK100_SHIFT) |
+		(exynos4x12_clkdiv_top[index][2] <<
+				EXYNOS4_CLKDIV_TOP_ACLK160_SHIFT) |
+		(exynos4x12_clkdiv_top[index][3] <<
+				EXYNOS4_CLKDIV_TOP_ACLK133_SHIFT) |
+		(exynos4x12_clkdiv_top[index][4] <<
+				EXYNOS4_CLKDIV_TOP_ONENAND_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_TOP);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_TOP);
+	} while (tmp & 0x11111);
+
+	/* Change Divider - LEFTBUS */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_LEFTBUS);
+
+	tmp &= ~(EXYNOS4_CLKDIV_BUS_GDLR_MASK | EXYNOS4_CLKDIV_BUS_GPLR_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_lr_bus[index][0] <<
+				EXYNOS4_CLKDIV_BUS_GDLR_SHIFT) |
+		(exynos4x12_clkdiv_lr_bus[index][1] <<
+				EXYNOS4_CLKDIV_BUS_GPLR_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_LEFTBUS);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_LEFTBUS);
+	} while (tmp & 0x11);
+
+	/* Change Divider - RIGHTBUS */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_RIGHTBUS);
+
+	tmp &= ~(EXYNOS4_CLKDIV_BUS_GDLR_MASK | EXYNOS4_CLKDIV_BUS_GPLR_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_lr_bus[index][0] <<
+				EXYNOS4_CLKDIV_BUS_GDLR_SHIFT) |
+		(exynos4x12_clkdiv_lr_bus[index][1] <<
+				EXYNOS4_CLKDIV_BUS_GPLR_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_RIGHTBUS);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_RIGHTBUS);
+	} while (tmp & 0x11);
+
+	/* Change Divider - MFC */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_MFC);
+
+	tmp &= ~(EXYNOS4_CLKDIV_MFC_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_sclkip[index][0] <<
+				EXYNOS4_CLKDIV_MFC_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_MFC);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_MFC);
+	} while (tmp & 0x1);
+
+	/* Change Divider - JPEG */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_CAM1);
+
+	tmp &= ~(EXYNOS4_CLKDIV_CAM1_JPEG_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_sclkip[index][1] <<
+				EXYNOS4_CLKDIV_CAM1_JPEG_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_CAM1);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_CAM1);
+	} while (tmp & 0x1);
+
+	/* Change Divider - FIMC0~3 */
+	tmp = __raw_readl(EXYNOS4_CLKDIV_CAM);
+
+	tmp &= ~(EXYNOS4_CLKDIV_CAM_FIMC0_MASK | EXYNOS4_CLKDIV_CAM_FIMC1_MASK |
+		EXYNOS4_CLKDIV_CAM_FIMC2_MASK | EXYNOS4_CLKDIV_CAM_FIMC3_MASK);
+
+	tmp |= ((exynos4x12_clkdiv_sclkip[index][2] <<
+				EXYNOS4_CLKDIV_CAM_FIMC0_SHIFT) |
+		(exynos4x12_clkdiv_sclkip[index][2] <<
+				EXYNOS4_CLKDIV_CAM_FIMC1_SHIFT) |
+		(exynos4x12_clkdiv_sclkip[index][2] <<
+				EXYNOS4_CLKDIV_CAM_FIMC2_SHIFT) |
+		(exynos4x12_clkdiv_sclkip[index][2] <<
+				EXYNOS4_CLKDIV_CAM_FIMC3_SHIFT));
+
+	__raw_writel(tmp, EXYNOS4_CLKDIV_CAM);
+
+	do {
+		tmp = __raw_readl(EXYNOS4_CLKDIV_STAT_CAM1);
+	} while (tmp & 0x1111);
+
+	return 0;
+}
+
+static int exynos4x12_get_intspec(unsigned long mifclk)
+{
+	int i = 0;
+
+	while (exynos4x12_intclk_table[i].clk) {
+		if (exynos4x12_intclk_table[i].clk <= mifclk)
+			return i;
+		i++;
+	}
+
+	return -EINVAL;
+}
+
+static int exynos4_bus_setvolt(struct busfreq_data *data,
+			       struct busfreq_opp_info *oppi,
+			       struct busfreq_opp_info *oldoppi)
+{
+	int err = 0, tmp;
+	unsigned long volt = oppi->volt;
+
+	switch (data->type) {
+	case TYPE_BUSF_EXYNOS4210:
+		/* OPP represents DMC clock + INT voltage */
+		err = regulator_set_voltage(data->vdd_int, volt,
+					    MAX_SAFEVOLT);
+		break;
+	case TYPE_BUSF_EXYNOS4x12:
+		/* OPP represents MIF clock + MIF voltage */
+		err = regulator_set_voltage(data->vdd_mif, volt,
+					    MAX_SAFEVOLT);
+		if (err)
+			break;
+
+		tmp = exynos4x12_get_intspec(oppi->rate);
+		if (tmp < 0) {
+			err = tmp;
+			regulator_set_voltage(data->vdd_mif,
+					      oldoppi->volt,
+					      MAX_SAFEVOLT);
+			break;
+		}
+		err = regulator_set_voltage(data->vdd_int,
+					    exynos4x12_intclk_table[tmp].volt,
+					    MAX_SAFEVOLT);
+		/*  Try to recover */
+		if (err)
+			regulator_set_voltage(data->vdd_mif,
+					      oldoppi->volt,
+					      MAX_SAFEVOLT);
+		break;
+	default:
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
+static int exynos4_bus_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 *data = platform_get_drvdata(pdev);
+	struct dev_pm_opp *opp;
+	unsigned long freq;
+	unsigned long old_freq = data->curr_oppinfo.rate;
+	struct busfreq_opp_info	new_oppinfo;
+
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, _freq, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		return PTR_ERR(opp);
+	}
+	new_oppinfo.rate = dev_pm_opp_get_freq(opp);
+	new_oppinfo.volt = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+	freq = new_oppinfo.rate;
+
+	if (old_freq == freq)
+		return 0;
+
+	dev_dbg(dev, "targeting %lukHz %luuV\n", freq, new_oppinfo.volt);
+
+	mutex_lock(&data->lock);
+
+	if (data->disabled)
+		goto out;
+
+	if (old_freq < freq)
+		err = exynos4_bus_setvolt(data, &new_oppinfo,
+					  &data->curr_oppinfo);
+	if (err)
+		goto out;
+
+	if (old_freq != freq) {
+		switch (data->type) {
+		case TYPE_BUSF_EXYNOS4210:
+			err = exynos4210_set_busclk(data, &new_oppinfo);
+			break;
+		case TYPE_BUSF_EXYNOS4x12:
+			err = exynos4x12_set_busclk(data, &new_oppinfo);
+			break;
+		default:
+			err = -EINVAL;
+		}
+	}
+	if (err)
+		goto out;
+
+	if (old_freq > freq)
+		err = exynos4_bus_setvolt(data, &new_oppinfo,
+					  &data->curr_oppinfo);
+	if (err)
+		goto out;
+
+	data->curr_oppinfo = new_oppinfo;
+out:
+	mutex_unlock(&data->lock);
+	return err;
+}
+
+static int exynos4_bus_get_dev_status(struct device *dev,
+				      struct devfreq_dev_status *stat)
+{
+	struct busfreq_data *data = dev_get_drvdata(dev);
+	struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data;
+	int busier;
+
+	exynos_read_ppmu(ppmu_data);
+	busier = exynos_get_busier_ppmu(ppmu_data);
+	stat->current_frequency = data->curr_oppinfo.rate;
+
+	/* Number of cycles spent on memory access */
+	stat->busy_time = ppmu_data->ppmu[busier].count[PPMU_PMNCNT3];
+	stat->busy_time *= 100 / BUS_SATURATION_RATIO;
+	stat->total_time = ppmu_data->ppmu[busier].ccnt;
+
+	/* If the counters have overflown, retry */
+	if (ppmu_data->ppmu[busier].ccnt_overflow ||
+	    ppmu_data->ppmu[busier].count_overflow[0])
+		return -EAGAIN;
+
+	return 0;
+}
+
+static struct devfreq_dev_profile exynos4_devfreq_profile = {
+	.initial_freq	= 400000,
+	.polling_ms	= 50,
+	.target		= exynos4_bus_target,
+	.get_dev_status	= exynos4_bus_get_dev_status,
+};
+
+static int exynos4210_init_tables(struct busfreq_data *data)
+{
+	u32 tmp;
+	int mgrp;
+	int i, err = 0;
+
+	tmp = __raw_readl(EXYNOS4_CLKDIV_DMC0);
+	for (i = LV_0; i < EX4210_LV_NUM; i++) {
+		tmp &= ~(EXYNOS4_CLKDIV_DMC0_ACP_MASK |
+			EXYNOS4_CLKDIV_DMC0_ACPPCLK_MASK |
+			EXYNOS4_CLKDIV_DMC0_DPHY_MASK |
+			EXYNOS4_CLKDIV_DMC0_DMC_MASK |
+			EXYNOS4_CLKDIV_DMC0_DMCD_MASK |
+			EXYNOS4_CLKDIV_DMC0_DMCP_MASK |
+			EXYNOS4_CLKDIV_DMC0_COPY2_MASK |
+			EXYNOS4_CLKDIV_DMC0_CORETI_MASK);
+
+		tmp |= ((exynos4210_clkdiv_dmc0[i][0] <<
+					EXYNOS4_CLKDIV_DMC0_ACP_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][1] <<
+					EXYNOS4_CLKDIV_DMC0_ACPPCLK_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][2] <<
+					EXYNOS4_CLKDIV_DMC0_DPHY_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][3] <<
+					EXYNOS4_CLKDIV_DMC0_DMC_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][4] <<
+					EXYNOS4_CLKDIV_DMC0_DMCD_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][5] <<
+					EXYNOS4_CLKDIV_DMC0_DMCP_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][6] <<
+					EXYNOS4_CLKDIV_DMC0_COPY2_SHIFT) |
+			(exynos4210_clkdiv_dmc0[i][7] <<
+					EXYNOS4_CLKDIV_DMC0_CORETI_SHIFT));
+
+		data->dmc_divtable[i] = tmp;
+	}
+
+	tmp = __raw_readl(EXYNOS4_CLKDIV_TOP);
+	for (i = LV_0; i <  EX4210_LV_NUM; i++) {
+		tmp &= ~(EXYNOS4_CLKDIV_TOP_ACLK200_MASK |
+			EXYNOS4_CLKDIV_TOP_ACLK100_MASK |
+			EXYNOS4_CLKDIV_TOP_ACLK160_MASK |
+			EXYNOS4_CLKDIV_TOP_ACLK133_MASK |
+			EXYNOS4_CLKDIV_TOP_ONENAND_MASK);
+
+		tmp |= ((exynos4210_clkdiv_top[i][0] <<
+					EXYNOS4_CLKDIV_TOP_ACLK200_SHIFT) |
+			(exynos4210_clkdiv_top[i][1] <<
+					EXYNOS4_CLKDIV_TOP_ACLK100_SHIFT) |
+			(exynos4210_clkdiv_top[i][2] <<
+					EXYNOS4_CLKDIV_TOP_ACLK160_SHIFT) |
+			(exynos4210_clkdiv_top[i][3] <<
+					EXYNOS4_CLKDIV_TOP_ACLK133_SHIFT) |
+			(exynos4210_clkdiv_top[i][4] <<
+					EXYNOS4_CLKDIV_TOP_ONENAND_SHIFT));
+
+		data->top_divtable[i] = tmp;
+	}
+
+	/*
+	 * TODO: init tmp based on busfreq_data
+	 * (device-tree or platform-data)
+	 */
+	tmp = 0; /* Max voltages for the reliability of the unknown */
+
+	pr_debug("ASV Group of Exynos4 is %d\n", tmp);
+	/* Use merged grouping for voltage */
+	switch (tmp) {
+	case 0:
+		mgrp = 0;
+		break;
+	case 1:
+	case 2:
+		mgrp = 1;
+		break;
+	case 3:
+	case 4:
+		mgrp = 2;
+		break;
+	case 5:
+	case 6:
+		mgrp = 3;
+		break;
+	case 7:
+		mgrp = 4;
+		break;
+	default:
+		pr_warn("Unknown ASV Group. Use max voltage.\n");
+		mgrp = 0;
+	}
+
+	for (i = LV_0; i < EX4210_LV_NUM; i++)
+		exynos4210_busclk_table[i].volt = exynos4210_asv_volt[mgrp][i];
+
+	for (i = LV_0; i < EX4210_LV_NUM; i++) {
+		err = dev_pm_opp_add(data->dev, exynos4210_busclk_table[i].clk,
+			      exynos4210_busclk_table[i].volt);
+		if (err) {
+			dev_err(data->dev, "Cannot add opp entries.\n");
+			return err;
+		}
+	}
+
+
+	return 0;
+}
+
+static int exynos4x12_init_tables(struct busfreq_data *data)
+{
+	unsigned int i;
+	unsigned int tmp;
+	int ret;
+
+	/* Enable pause function for DREX2 DVFS */
+	tmp = __raw_readl(EXYNOS4_DMC_PAUSE_CTRL);
+	tmp |= EXYNOS4_DMC_PAUSE_ENABLE;
+	__raw_writel(tmp, EXYNOS4_DMC_PAUSE_CTRL);
+
+	tmp = __raw_readl(EXYNOS4_CLKDIV_DMC0);
+
+	for (i = 0; i <  EX4x12_LV_NUM; i++) {
+		tmp &= ~(EXYNOS4_CLKDIV_DMC0_ACP_MASK |
+			EXYNOS4_CLKDIV_DMC0_ACPPCLK_MASK |
+			EXYNOS4_CLKDIV_DMC0_DPHY_MASK |
+			EXYNOS4_CLKDIV_DMC0_DMC_MASK |
+			EXYNOS4_CLKDIV_DMC0_DMCD_MASK |
+			EXYNOS4_CLKDIV_DMC0_DMCP_MASK);
+
+		tmp |= ((exynos4x12_clkdiv_dmc0[i][0] <<
+					EXYNOS4_CLKDIV_DMC0_ACP_SHIFT) |
+			(exynos4x12_clkdiv_dmc0[i][1] <<
+					EXYNOS4_CLKDIV_DMC0_ACPPCLK_SHIFT) |
+			(exynos4x12_clkdiv_dmc0[i][2] <<
+					EXYNOS4_CLKDIV_DMC0_DPHY_SHIFT) |
+			(exynos4x12_clkdiv_dmc0[i][3] <<
+					EXYNOS4_CLKDIV_DMC0_DMC_SHIFT) |
+			(exynos4x12_clkdiv_dmc0[i][4] <<
+					EXYNOS4_CLKDIV_DMC0_DMCD_SHIFT) |
+			(exynos4x12_clkdiv_dmc0[i][5] <<
+					EXYNOS4_CLKDIV_DMC0_DMCP_SHIFT));
+
+		data->dmc_divtable[i] = tmp;
+	}
+
+	tmp = 0; /* Max voltages for the reliability of the unknown */
+
+	if (tmp > 8)
+		tmp = 0;
+	pr_debug("ASV Group of Exynos4x12 is %d\n", tmp);
+
+	for (i = 0; i < EX4x12_LV_NUM; i++) {
+		exynos4x12_mifclk_table[i].volt =
+			exynos4x12_mif_step_50[tmp][i];
+		exynos4x12_intclk_table[i].volt =
+			exynos4x12_int_volt[tmp][i];
+	}
+
+	for (i = 0; i < EX4x12_LV_NUM; i++) {
+		ret = dev_pm_opp_add(data->dev, exynos4x12_mifclk_table[i].clk,
+			      exynos4x12_mifclk_table[i].volt);
+		if (ret) {
+			dev_err(data->dev, "Fail to add opp entries.\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int exynos4_busfreq_pm_notifier_event(struct notifier_block *this,
+		unsigned long event, void *ptr)
+{
+	struct busfreq_data *data = container_of(this, struct busfreq_data,
+						 pm_notifier);
+	struct dev_pm_opp *opp;
+	struct busfreq_opp_info	new_oppinfo;
+	unsigned long maxfreq = ULONG_MAX;
+	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 = dev_pm_opp_find_freq_floor(data->dev, &maxfreq);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			dev_err(data->dev, "%s: unable to find a min freq\n",
+				__func__);
+			mutex_unlock(&data->lock);
+			return PTR_ERR(opp);
+		}
+		new_oppinfo.rate = dev_pm_opp_get_freq(opp);
+		new_oppinfo.volt = dev_pm_opp_get_voltage(opp);
+		rcu_read_unlock();
+
+		err = exynos4_bus_setvolt(data, &new_oppinfo,
+					  &data->curr_oppinfo);
+		if (err)
+			goto unlock;
+
+		switch (data->type) {
+		case TYPE_BUSF_EXYNOS4210:
+			err = exynos4210_set_busclk(data, &new_oppinfo);
+			break;
+		case TYPE_BUSF_EXYNOS4x12:
+			err = exynos4x12_set_busclk(data, &new_oppinfo);
+			break;
+		default:
+			err = -EINVAL;
+		}
+		if (err)
+			goto unlock;
+
+		data->curr_oppinfo = new_oppinfo;
+unlock:
+		mutex_unlock(&data->lock);
+		if (err)
+			return err;
+		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 int exynos4_busfreq_probe(struct platform_device *pdev)
+{
+	struct busfreq_data *data;
+	struct busfreq_ppmu_data *ppmu_data;
+	struct dev_pm_opp *opp;
+	struct device *dev = &pdev->dev;
+	int err = 0;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data), GFP_KERNEL);
+	if (data == NULL) {
+		dev_err(dev, "Cannot allocate memory.\n");
+		return -ENOMEM;
+	}
+
+	ppmu_data = &data->ppmu_data;
+	ppmu_data->ppmu_end = PPMU_END;
+	ppmu_data->ppmu = devm_kzalloc(dev,
+				       sizeof(struct exynos_ppmu) * PPMU_END,
+				       GFP_KERNEL);
+	if (!ppmu_data->ppmu) {
+		dev_err(dev, "Failed to allocate memory for exynos_ppmu\n");
+		return -ENOMEM;
+	}
+
+	data->type = pdev->id_entry->driver_data;
+	ppmu_data->ppmu[PPMU_DMC0].hw_base = S5P_VA_DMC0;
+	ppmu_data->ppmu[PPMU_DMC1].hw_base = S5P_VA_DMC1;
+	data->pm_notifier.notifier_call = exynos4_busfreq_pm_notifier_event;
+	data->dev = dev;
+	mutex_init(&data->lock);
+
+	switch (data->type) {
+	case TYPE_BUSF_EXYNOS4210:
+		err = exynos4210_init_tables(data);
+		break;
+	case TYPE_BUSF_EXYNOS4x12:
+		err = exynos4x12_init_tables(data);
+		break;
+	default:
+		dev_err(dev, "Cannot determine the device id %d\n", data->type);
+		err = -EINVAL;
+	}
+	if (err) {
+		dev_err(dev, "Cannot initialize busfreq table %d\n",
+			     data->type);
+		return err;
+	}
+
+	data->vdd_int = devm_regulator_get(dev, "vdd_int");
+	if (IS_ERR(data->vdd_int)) {
+		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
+		return PTR_ERR(data->vdd_int);
+	}
+	if (data->type == TYPE_BUSF_EXYNOS4x12) {
+		data->vdd_mif = devm_regulator_get(dev, "vdd_mif");
+		if (IS_ERR(data->vdd_mif)) {
+			dev_err(dev, "Cannot get the regulator \"vdd_mif\"\n");
+			return PTR_ERR(data->vdd_mif);
+		}
+	}
+
+	rcu_read_lock();
+	opp = dev_pm_opp_find_freq_floor(dev,
+					 &exynos4_devfreq_profile.initial_freq);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "Invalid initial frequency %lu kHz.\n",
+			exynos4_devfreq_profile.initial_freq);
+		return PTR_ERR(opp);
+	}
+	data->curr_oppinfo.rate = dev_pm_opp_get_freq(opp);
+	data->curr_oppinfo.volt = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+
+	platform_set_drvdata(pdev, data);
+
+	data->devfreq = devm_devfreq_add_device(dev, &exynos4_devfreq_profile,
+					   "simple_ondemand", NULL);
+	if (IS_ERR(data->devfreq))
+		return PTR_ERR(data->devfreq);
+
+	/*
+	 * Start PPMU (Performance Profiling Monitoring Unit) to check
+	 * utilization of each IP in the Exynos4 SoC.
+	 */
+	busfreq_mon_reset(ppmu_data);
+
+	/* Register opp_notifier for Exynos4 busfreq */
+	err = devm_devfreq_register_opp_notifier(dev, data->devfreq);
+	if (err < 0) {
+		dev_err(dev, "Failed to register opp notifier\n");
+		return err;
+	}
+
+	/* Register pm_notifier for Exynos4 busfreq */
+	err = register_pm_notifier(&data->pm_notifier);
+	if (err) {
+		dev_err(dev, "Failed to setup pm notifier\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static int exynos4_busfreq_remove(struct platform_device *pdev)
+{
+	struct busfreq_data *data = platform_get_drvdata(pdev);
+
+	/* Unregister all of notifier chain */
+	unregister_pm_notifier(&data->pm_notifier);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int exynos4_busfreq_resume(struct device *dev)
+{
+	struct busfreq_data *data = dev_get_drvdata(dev);
+	struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data;
+
+	busfreq_mon_reset(ppmu_data);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(exynos4_busfreq_pm_ops, NULL, exynos4_busfreq_resume);
+
+static const struct platform_device_id exynos4_busfreq_id[] = {
+	{ "exynos4210-busfreq", TYPE_BUSF_EXYNOS4210 },
+	{ "exynos4412-busfreq", TYPE_BUSF_EXYNOS4x12 },
+	{ "exynos4212-busfreq", TYPE_BUSF_EXYNOS4x12 },
+	{ },
+};
+
+static struct platform_driver exynos4_busfreq_driver = {
+	.probe	= exynos4_busfreq_probe,
+	.remove	= exynos4_busfreq_remove,
+	.id_table = exynos4_busfreq_id,
+	.driver = {
+		.name	= "exynos4-busfreq",
+		.pm	= &exynos4_busfreq_pm_ops,
+	},
+};
+
+static int __init exynos4_busfreq_init(void)
+{
+	return platform_driver_register(&exynos4_busfreq_driver);
+}
+late_initcall(exynos4_busfreq_init);
+
+static void __exit exynos4_busfreq_exit(void)
+{
+	platform_driver_unregister(&exynos4_busfreq_driver);
+}
+module_exit(exynos4_busfreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EXYNOS4 busfreq driver with devfreq framework");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
diff --git a/drivers/devfreq/exynos/exynos4_bus.h b/drivers/devfreq/exynos/exynos4_bus.h
new file mode 100644
index 000000000..94c73c18d
--- /dev/null
+++ b/drivers/devfreq/exynos/exynos4_bus.h
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS4 BUS header
+ *
+ * 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.
+*/
+
+#ifndef __DEVFREQ_EXYNOS4_BUS_H
+#define __DEVFREQ_EXYNOS4_BUS_H __FILE__
+
+#include <mach/map.h>
+
+#define EXYNOS4_CLKDIV_LEFTBUS			(S5P_VA_CMU + 0x04500)
+#define EXYNOS4_CLKDIV_STAT_LEFTBUS		(S5P_VA_CMU + 0x04600)
+
+#define EXYNOS4_CLKDIV_RIGHTBUS			(S5P_VA_CMU + 0x08500)
+#define EXYNOS4_CLKDIV_STAT_RIGHTBUS		(S5P_VA_CMU + 0x08600)
+
+#define EXYNOS4_CLKDIV_TOP			(S5P_VA_CMU + 0x0C510)
+#define EXYNOS4_CLKDIV_CAM			(S5P_VA_CMU + 0x0C520)
+#define EXYNOS4_CLKDIV_MFC			(S5P_VA_CMU + 0x0C528)
+
+#define EXYNOS4_CLKDIV_STAT_TOP			(S5P_VA_CMU + 0x0C610)
+#define EXYNOS4_CLKDIV_STAT_MFC			(S5P_VA_CMU + 0x0C628)
+
+#define EXYNOS4210_CLKGATE_IP_IMAGE		(S5P_VA_CMU + 0x0C930)
+#define EXYNOS4212_CLKGATE_IP_IMAGE		(S5P_VA_CMU + 0x04930)
+
+#define EXYNOS4_CLKDIV_DMC0			(S5P_VA_CMU + 0x10500)
+#define EXYNOS4_CLKDIV_DMC1			(S5P_VA_CMU + 0x10504)
+#define EXYNOS4_CLKDIV_STAT_DMC0		(S5P_VA_CMU + 0x10600)
+#define EXYNOS4_CLKDIV_STAT_DMC1		(S5P_VA_CMU + 0x10604)
+
+#define EXYNOS4_DMC_PAUSE_CTRL			(S5P_VA_CMU + 0x11094)
+#define EXYNOS4_DMC_PAUSE_ENABLE		(1 << 0)
+
+#define EXYNOS4_CLKDIV_DMC0_ACP_SHIFT		(0)
+#define EXYNOS4_CLKDIV_DMC0_ACP_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_ACP_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_ACPPCLK_SHIFT	(4)
+#define EXYNOS4_CLKDIV_DMC0_ACPPCLK_MASK	(0x7 << EXYNOS4_CLKDIV_DMC0_ACPPCLK_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_DPHY_SHIFT		(8)
+#define EXYNOS4_CLKDIV_DMC0_DPHY_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DPHY_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_DMC_SHIFT		(12)
+#define EXYNOS4_CLKDIV_DMC0_DMC_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DMC_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_DMCD_SHIFT		(16)
+#define EXYNOS4_CLKDIV_DMC0_DMCD_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DMCD_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_DMCP_SHIFT		(20)
+#define EXYNOS4_CLKDIV_DMC0_DMCP_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DMCP_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_COPY2_SHIFT		(24)
+#define EXYNOS4_CLKDIV_DMC0_COPY2_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_COPY2_SHIFT)
+#define EXYNOS4_CLKDIV_DMC0_CORETI_SHIFT	(28)
+#define EXYNOS4_CLKDIV_DMC0_CORETI_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_CORETI_SHIFT)
+
+#define EXYNOS4_CLKDIV_DMC1_G2D_ACP_SHIFT	(0)
+#define EXYNOS4_CLKDIV_DMC1_G2D_ACP_MASK	(0xf << EXYNOS4_CLKDIV_DMC1_G2D_ACP_SHIFT)
+#define EXYNOS4_CLKDIV_DMC1_C2C_SHIFT		(4)
+#define EXYNOS4_CLKDIV_DMC1_C2C_MASK		(0x7 << EXYNOS4_CLKDIV_DMC1_C2C_SHIFT)
+#define EXYNOS4_CLKDIV_DMC1_PWI_SHIFT		(8)
+#define EXYNOS4_CLKDIV_DMC1_PWI_MASK		(0xf << EXYNOS4_CLKDIV_DMC1_PWI_SHIFT)
+#define EXYNOS4_CLKDIV_DMC1_C2CACLK_SHIFT	(12)
+#define EXYNOS4_CLKDIV_DMC1_C2CACLK_MASK	(0x7 << EXYNOS4_CLKDIV_DMC1_C2CACLK_SHIFT)
+#define EXYNOS4_CLKDIV_DMC1_DVSEM_SHIFT		(16)
+#define EXYNOS4_CLKDIV_DMC1_DVSEM_MASK		(0x7f << EXYNOS4_CLKDIV_DMC1_DVSEM_SHIFT)
+#define EXYNOS4_CLKDIV_DMC1_DPM_SHIFT		(24)
+#define EXYNOS4_CLKDIV_DMC1_DPM_MASK		(0x7f << EXYNOS4_CLKDIV_DMC1_DPM_SHIFT)
+
+#define EXYNOS4_CLKDIV_MFC_SHIFT		(0)
+#define EXYNOS4_CLKDIV_MFC_MASK			(0x7 << EXYNOS4_CLKDIV_MFC_SHIFT)
+
+#define EXYNOS4_CLKDIV_TOP_ACLK200_SHIFT	(0)
+#define EXYNOS4_CLKDIV_TOP_ACLK200_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ACLK200_SHIFT)
+#define EXYNOS4_CLKDIV_TOP_ACLK100_SHIFT	(4)
+#define EXYNOS4_CLKDIV_TOP_ACLK100_MASK		(0xF << EXYNOS4_CLKDIV_TOP_ACLK100_SHIFT)
+#define EXYNOS4_CLKDIV_TOP_ACLK160_SHIFT	(8)
+#define EXYNOS4_CLKDIV_TOP_ACLK160_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ACLK160_SHIFT)
+#define EXYNOS4_CLKDIV_TOP_ACLK133_SHIFT	(12)
+#define EXYNOS4_CLKDIV_TOP_ACLK133_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ACLK133_SHIFT)
+#define EXYNOS4_CLKDIV_TOP_ONENAND_SHIFT	(16)
+#define EXYNOS4_CLKDIV_TOP_ONENAND_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ONENAND_SHIFT)
+#define EXYNOS4_CLKDIV_TOP_ACLK266_GPS_SHIFT	(20)
+#define EXYNOS4_CLKDIV_TOP_ACLK266_GPS_MASK	(0x7 << EXYNOS4_CLKDIV_TOP_ACLK266_GPS_SHIFT)
+#define EXYNOS4_CLKDIV_TOP_ACLK400_MCUISP_SHIFT	(24)
+#define EXYNOS4_CLKDIV_TOP_ACLK400_MCUISP_MASK	(0x7 << EXYNOS4_CLKDIV_TOP_ACLK400_MCUISP_SHIFT)
+
+#define EXYNOS4_CLKDIV_BUS_GDLR_SHIFT		(0)
+#define EXYNOS4_CLKDIV_BUS_GDLR_MASK		(0x7 << EXYNOS4_CLKDIV_BUS_GDLR_SHIFT)
+#define EXYNOS4_CLKDIV_BUS_GPLR_SHIFT		(4)
+#define EXYNOS4_CLKDIV_BUS_GPLR_MASK		(0x7 << EXYNOS4_CLKDIV_BUS_GPLR_SHIFT)
+
+#define EXYNOS4_CLKDIV_CAM_FIMC0_SHIFT		(0)
+#define EXYNOS4_CLKDIV_CAM_FIMC0_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC0_SHIFT)
+#define EXYNOS4_CLKDIV_CAM_FIMC1_SHIFT		(4)
+#define EXYNOS4_CLKDIV_CAM_FIMC1_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC1_SHIFT)
+#define EXYNOS4_CLKDIV_CAM_FIMC2_SHIFT		(8)
+#define EXYNOS4_CLKDIV_CAM_FIMC2_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC2_SHIFT)
+#define EXYNOS4_CLKDIV_CAM_FIMC3_SHIFT		(12)
+#define EXYNOS4_CLKDIV_CAM_FIMC3_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC3_SHIFT)
+
+#define EXYNOS4_CLKDIV_CAM1			(S5P_VA_CMU + 0x0C568)
+
+#define EXYNOS4_CLKDIV_STAT_CAM1		(S5P_VA_CMU + 0x0C668)
+
+#define EXYNOS4_CLKDIV_CAM1_JPEG_SHIFT		(0)
+#define EXYNOS4_CLKDIV_CAM1_JPEG_MASK		(0xf << EXYNOS4_CLKDIV_CAM1_JPEG_SHIFT)
+
+#endif /* __DEVFREQ_EXYNOS4_BUS_H */
diff --git a/drivers/devfreq/exynos/exynos5_bus.c b/drivers/devfreq/exynos/exynos5_bus.c
new file mode 100644
index 000000000..297ea30d4
--- /dev/null
+++ b/drivers/devfreq/exynos/exynos5_bus.c
@@ -0,0 +1,431 @@
+/*
+ * 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/devfreq.h>
+#include <linux/io.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include <linux/suspend.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 <linux/of_address.h>
+#include <linux/of_platform.h>
+
+#include "exynos_ppmu.h"
+
+#define MAX_SAFEVOLT			1100000 /* 1.10V */
+/* Assume that the bus is saturated if the utilization is 25% */
+#define INT_BUS_SATURATION_RATIO	25
+
+enum int_level_idx {
+	LV_0,
+	LV_1,
+	LV_2,
+	LV_3,
+	LV_4,
+	_LV_END
+};
+
+enum exynos_ppmu_list {
+	PPMU_RIGHT,
+	PPMU_END,
+};
+
+struct busfreq_data_int {
+	struct device *dev;
+	struct devfreq *devfreq;
+	struct regulator *vdd_int;
+	struct busfreq_ppmu_data ppmu_data;
+	unsigned long curr_freq;
+	bool disabled;
+
+	struct notifier_block pm_notifier;
+	struct mutex lock;
+	struct pm_qos_request int_req;
+	struct clk *int_clk;
+};
+
+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 dev_pm_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 = dev_pm_opp_get_freq(opp);
+	volt = dev_pm_opp_get_voltage(opp);
+	rcu_read_unlock();
+
+	old_freq = data->curr_freq;
+
+	if (old_freq == freq)
+		return 0;
+
+	dev_dbg(dev, "targeting %lukHz %luuV\n", freq, volt);
+
+	mutex_lock(&data->lock);
+
+	if (data->disabled)
+		goto out;
+
+	if (freq > exynos5_int_opp_table[0].clk)
+		pm_qos_update_request(&data->int_req, freq * 16 / 1000);
+	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);
+	struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data;
+	int busier_dmc;
+
+	exynos_read_ppmu(ppmu_data);
+	busier_dmc = exynos_get_busier_ppmu(ppmu_data);
+
+	stat->current_frequency = data->curr_freq;
+
+	/* Number of cycles spent on memory access */
+	stat->busy_time = ppmu_data->ppmu[busier_dmc].count[PPMU_PMNCNT3];
+	stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO;
+	stat->total_time = ppmu_data->ppmu[busier_dmc].ccnt;
+
+	return 0;
+}
+
+static struct devfreq_dev_profile exynos5_devfreq_int_profile = {
+	.initial_freq		= 160000,
+	.polling_ms		= 100,
+	.target			= exynos5_busfreq_int_target,
+	.get_dev_status		= exynos5_int_get_dev_status,
+};
+
+static int exynos5250_init_int_tables(struct busfreq_data_int *data)
+{
+	int i, err = 0;
+
+	for (i = LV_0; i < _LV_END; i++) {
+		err = dev_pm_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 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 dev_pm_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 = dev_pm_opp_find_freq_floor(data->dev, &maxfreq);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			err = PTR_ERR(opp);
+			goto unlock;
+		}
+		freq = dev_pm_opp_get_freq(opp);
+		volt = dev_pm_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 int exynos5_busfreq_int_probe(struct platform_device *pdev)
+{
+	struct busfreq_data_int *data;
+	struct busfreq_ppmu_data *ppmu_data;
+	struct dev_pm_opp *opp;
+	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	unsigned long initial_freq;
+	unsigned long initial_volt;
+	int err = 0;
+	int i;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int),
+				GFP_KERNEL);
+	if (data == NULL) {
+		dev_err(dev, "Cannot allocate memory.\n");
+		return -ENOMEM;
+	}
+
+	ppmu_data = &data->ppmu_data;
+	ppmu_data->ppmu_end = PPMU_END;
+	ppmu_data->ppmu = devm_kzalloc(dev,
+				       sizeof(struct exynos_ppmu) * PPMU_END,
+				       GFP_KERNEL);
+	if (!ppmu_data->ppmu) {
+		dev_err(dev, "Failed to allocate memory for exynos_ppmu\n");
+		return -ENOMEM;
+	}
+
+	np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu");
+	if (np == NULL) {
+		pr_err("Unable to find PPMU node\n");
+		return -ENOENT;
+	}
+
+	for (i = 0; i < ppmu_data->ppmu_end; i++) {
+		/* map PPMU memory region */
+		ppmu_data->ppmu[i].hw_base = of_iomap(np, i);
+		if (ppmu_data->ppmu[i].hw_base == NULL) {
+			dev_err(&pdev->dev, "failed to map memory region\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)
+		return err;
+
+	data->vdd_int = devm_regulator_get(dev, "vdd_int");
+	if (IS_ERR(data->vdd_int)) {
+		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
+		return PTR_ERR(data->vdd_int);
+	}
+
+	data->int_clk = devm_clk_get(dev, "int_clk");
+	if (IS_ERR(data->int_clk)) {
+		dev_err(dev, "Cannot get clock \"int_clk\"\n");
+		return PTR_ERR(data->int_clk);
+	}
+
+	rcu_read_lock();
+	opp = dev_pm_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);
+		return PTR_ERR(opp);
+	}
+	initial_freq = dev_pm_opp_get_freq(opp);
+	initial_volt = dev_pm_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");
+		return err;
+	}
+
+	err = exynos5_int_setvolt(data, initial_volt);
+	if (err)
+		return err;
+
+	platform_set_drvdata(pdev, data);
+
+	busfreq_mon_reset(ppmu_data);
+
+	data->devfreq = devm_devfreq_add_device(dev, &exynos5_devfreq_int_profile,
+					   "simple_ondemand", NULL);
+	if (IS_ERR(data->devfreq))
+		return PTR_ERR(data->devfreq);
+
+	err = devm_devfreq_register_opp_notifier(dev, data->devfreq);
+	if (err < 0) {
+		dev_err(dev, "Failed to register opp notifier\n");
+		return err;
+	}
+
+	err = register_pm_notifier(&data->pm_notifier);
+	if (err) {
+		dev_err(dev, "Failed to setup pm notifier\n");
+		return err;
+	}
+
+	/* TODO: Add a new QOS class for int/mif bus */
+	pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1);
+
+	return 0;
+}
+
+static 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);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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);
+	struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data;
+
+	busfreq_mon_reset(ppmu_data);
+	return 0;
+}
+static const struct dev_pm_ops exynos5_busfreq_int_pm = {
+	.resume	= exynos5_busfreq_int_resume,
+};
+#endif
+static SIMPLE_DEV_PM_OPS(exynos5_busfreq_int_pm_ops, NULL,
+			 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		= exynos5_busfreq_int_remove,
+	.driver		= {
+		.name		= "exynos5-bus-int",
+		.pm		= &exynos5_busfreq_int_pm_ops,
+	},
+};
+
+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(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");
diff --git a/drivers/devfreq/exynos/exynos_ppmu.c b/drivers/devfreq/exynos/exynos_ppmu.c
new file mode 100644
index 000000000..97b75e513
--- /dev/null
+++ b/drivers/devfreq/exynos/exynos_ppmu.c
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS - PPMU support
+ *
+ * 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/kernel.h>
+#include <linux/types.h>
+#include <linux/io.h>
+
+#include "exynos_ppmu.h"
+
+void exynos_ppmu_reset(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_CYCLE_RESET | PPMU_COUNTER_RESET, ppmu_base);
+	__raw_writel(PPMU_ENABLE_CYCLE  |
+		     PPMU_ENABLE_COUNT0 |
+		     PPMU_ENABLE_COUNT1 |
+		     PPMU_ENABLE_COUNT2 |
+		     PPMU_ENABLE_COUNT3,
+		     ppmu_base + PPMU_CNTENS);
+}
+
+void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
+			unsigned int evt)
+{
+	__raw_writel(evt, ppmu_base + PPMU_BEVTSEL(ch));
+}
+
+void exynos_ppmu_start(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_ENABLE, ppmu_base);
+}
+
+void exynos_ppmu_stop(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_DISABLE, ppmu_base);
+}
+
+unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch)
+{
+	unsigned int total;
+
+	if (ch == PPMU_PMNCNT3)
+		total = ((__raw_readl(ppmu_base + PMCNT_OFFSET(ch)) << 8) |
+			  __raw_readl(ppmu_base + PMCNT_OFFSET(ch + 1)));
+	else
+		total = __raw_readl(ppmu_base + PMCNT_OFFSET(ch));
+
+	return total;
+}
+
+void busfreq_mon_reset(struct busfreq_ppmu_data *ppmu_data)
+{
+	unsigned int i;
+
+	for (i = 0; i < ppmu_data->ppmu_end; i++) {
+		void __iomem *ppmu_base = ppmu_data->ppmu[i].hw_base;
+
+		/* Reset the performance and cycle counters */
+		exynos_ppmu_reset(ppmu_base);
+
+		/* Setup count registers to monitor read/write transactions */
+		ppmu_data->ppmu[i].event[PPMU_PMNCNT3] = RDWR_DATA_COUNT;
+		exynos_ppmu_setevent(ppmu_base, PPMU_PMNCNT3,
+					ppmu_data->ppmu[i].event[PPMU_PMNCNT3]);
+
+		exynos_ppmu_start(ppmu_base);
+	}
+}
+EXPORT_SYMBOL(busfreq_mon_reset);
+
+void exynos_read_ppmu(struct busfreq_ppmu_data *ppmu_data)
+{
+	int i, j;
+
+	for (i = 0; i < ppmu_data->ppmu_end; i++) {
+		void __iomem *ppmu_base = ppmu_data->ppmu[i].hw_base;
+
+		exynos_ppmu_stop(ppmu_base);
+
+		/* Update local data from PPMU */
+		ppmu_data->ppmu[i].ccnt = __raw_readl(ppmu_base + PPMU_CCNT);
+
+		for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
+			if (ppmu_data->ppmu[i].event[j] == 0)
+				ppmu_data->ppmu[i].count[j] = 0;
+			else
+				ppmu_data->ppmu[i].count[j] =
+					exynos_ppmu_read(ppmu_base, j);
+		}
+	}
+
+	busfreq_mon_reset(ppmu_data);
+}
+EXPORT_SYMBOL(exynos_read_ppmu);
+
+int exynos_get_busier_ppmu(struct busfreq_ppmu_data *ppmu_data)
+{
+	unsigned int count = 0;
+	int i, j, busy = 0;
+
+	for (i = 0; i < ppmu_data->ppmu_end; i++) {
+		for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
+			if (ppmu_data->ppmu[i].count[j] > count) {
+				count = ppmu_data->ppmu[i].count[j];
+				busy = i;
+			}
+		}
+	}
+
+	return busy;
+}
+EXPORT_SYMBOL(exynos_get_busier_ppmu);
diff --git a/drivers/devfreq/exynos/exynos_ppmu.h b/drivers/devfreq/exynos/exynos_ppmu.h
new file mode 100644
index 000000000..71f17ba35
--- /dev/null
+++ b/drivers/devfreq/exynos/exynos_ppmu.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS PPMU header
+ *
+ * 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.
+*/
+
+#ifndef __DEVFREQ_EXYNOS_PPMU_H
+#define __DEVFREQ_EXYNOS_PPMU_H __FILE__
+
+#include <linux/ktime.h>
+
+/* For PPMU Control */
+#define PPMU_ENABLE             BIT(0)
+#define PPMU_DISABLE            0x0
+#define PPMU_CYCLE_RESET        BIT(1)
+#define PPMU_COUNTER_RESET      BIT(2)
+
+#define PPMU_ENABLE_COUNT0      BIT(0)
+#define PPMU_ENABLE_COUNT1      BIT(1)
+#define PPMU_ENABLE_COUNT2      BIT(2)
+#define PPMU_ENABLE_COUNT3      BIT(3)
+#define PPMU_ENABLE_CYCLE       BIT(31)
+
+#define PPMU_CNTENS		0x10
+#define PPMU_FLAG		0x50
+#define PPMU_CCNT_OVERFLOW	BIT(31)
+#define PPMU_CCNT		0x100
+
+#define PPMU_PMCNT0		0x110
+#define PPMU_PMCNT_OFFSET	0x10
+#define PMCNT_OFFSET(x)		(PPMU_PMCNT0 + (PPMU_PMCNT_OFFSET * x))
+
+#define PPMU_BEVT0SEL		0x1000
+#define PPMU_BEVTSEL_OFFSET	0x100
+#define PPMU_BEVTSEL(x)		(PPMU_BEVT0SEL + (ch * PPMU_BEVTSEL_OFFSET))
+
+/* For Event Selection */
+#define RD_DATA_COUNT		0x5
+#define WR_DATA_COUNT		0x6
+#define RDWR_DATA_COUNT		0x7
+
+enum ppmu_counter {
+	PPMU_PMNCNT0,
+	PPMU_PMCCNT1,
+	PPMU_PMNCNT2,
+	PPMU_PMNCNT3,
+	PPMU_PMNCNT_MAX,
+};
+
+struct bus_opp_table {
+	unsigned int idx;
+	unsigned long clk;
+	unsigned long volt;
+};
+
+struct exynos_ppmu {
+	void __iomem *hw_base;
+	unsigned int ccnt;
+	unsigned int event[PPMU_PMNCNT_MAX];
+	unsigned int count[PPMU_PMNCNT_MAX];
+	unsigned long long ns;
+	ktime_t reset_time;
+	bool ccnt_overflow;
+	bool count_overflow[PPMU_PMNCNT_MAX];
+};
+
+struct busfreq_ppmu_data {
+	struct exynos_ppmu *ppmu;
+	int ppmu_end;
+};
+
+void exynos_ppmu_reset(void __iomem *ppmu_base);
+void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
+			unsigned int evt);
+void exynos_ppmu_start(void __iomem *ppmu_base);
+void exynos_ppmu_stop(void __iomem *ppmu_base);
+unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch);
+void busfreq_mon_reset(struct busfreq_ppmu_data *ppmu_data);
+void exynos_read_ppmu(struct busfreq_ppmu_data *ppmu_data);
+int exynos_get_busier_ppmu(struct busfreq_ppmu_data *ppmu_data);
+#endif /* __DEVFREQ_EXYNOS_PPMU_H */
diff --git a/drivers/devfreq/governor.h b/drivers/devfreq/governor.h
new file mode 100644
index 000000000..fad7d6321
--- /dev/null
+++ b/drivers/devfreq/governor.h
@@ -0,0 +1,41 @@
+/*
+ * governor.h - internal header for devfreq governors.
+ *
+ * Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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.
+ *
+ * This header is for devfreq governors in drivers/devfreq/
+ */
+
+#ifndef _GOVERNOR_H
+#define _GOVERNOR_H
+
+#include <linux/devfreq.h>
+
+#define to_devfreq(DEV)	container_of((DEV), struct devfreq, dev)
+
+/* Devfreq events */
+#define DEVFREQ_GOV_START			0x1
+#define DEVFREQ_GOV_STOP			0x2
+#define DEVFREQ_GOV_INTERVAL			0x3
+#define DEVFREQ_GOV_SUSPEND			0x4
+#define DEVFREQ_GOV_RESUME			0x5
+
+/* Caution: devfreq->lock must be locked before calling update_devfreq */
+extern int update_devfreq(struct devfreq *devfreq);
+
+extern void devfreq_monitor_start(struct devfreq *devfreq);
+extern void devfreq_monitor_stop(struct devfreq *devfreq);
+extern void devfreq_monitor_suspend(struct devfreq *devfreq);
+extern void devfreq_monitor_resume(struct devfreq *devfreq);
+extern void devfreq_interval_update(struct devfreq *devfreq,
+					unsigned int *delay);
+
+extern int devfreq_add_governor(struct devfreq_governor *governor);
+extern int devfreq_remove_governor(struct devfreq_governor *governor);
+
+#endif /* _GOVERNOR_H */
diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
new file mode 100644
index 000000000..c72f942f3
--- /dev/null
+++ b/drivers/devfreq/governor_performance.c
@@ -0,0 +1,67 @@
+/*
+ *  linux/drivers/devfreq/governor_performance.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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/devfreq.h>
+#include <linux/module.h>
+#include "governor.h"
+
+static int devfreq_performance_func(struct devfreq *df,
+				    unsigned long *freq)
+{
+	/*
+	 * target callback should be able to get floor value as
+	 * said in devfreq.h
+	 */
+	if (!df->max_freq)
+		*freq = UINT_MAX;
+	else
+		*freq = df->max_freq;
+	return 0;
+}
+
+static int devfreq_performance_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	int ret = 0;
+
+	if (event == DEVFREQ_GOV_START) {
+		mutex_lock(&devfreq->lock);
+		ret = update_devfreq(devfreq);
+		mutex_unlock(&devfreq->lock);
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_performance = {
+	.name = "performance",
+	.get_target_freq = devfreq_performance_func,
+	.event_handler = devfreq_performance_handler,
+};
+
+static int __init devfreq_performance_init(void)
+{
+	return devfreq_add_governor(&devfreq_performance);
+}
+subsys_initcall(devfreq_performance_init);
+
+static void __exit devfreq_performance_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_performance);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_performance_exit);
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c
new file mode 100644
index 000000000..0c6bed567
--- /dev/null
+++ b/drivers/devfreq/governor_powersave.c
@@ -0,0 +1,64 @@
+/*
+ *  linux/drivers/devfreq/governor_powersave.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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/devfreq.h>
+#include <linux/module.h>
+#include "governor.h"
+
+static int devfreq_powersave_func(struct devfreq *df,
+				  unsigned long *freq)
+{
+	/*
+	 * target callback should be able to get ceiling value as
+	 * said in devfreq.h
+	 */
+	*freq = df->min_freq;
+	return 0;
+}
+
+static int devfreq_powersave_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	int ret = 0;
+
+	if (event == DEVFREQ_GOV_START) {
+		mutex_lock(&devfreq->lock);
+		ret = update_devfreq(devfreq);
+		mutex_unlock(&devfreq->lock);
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_powersave = {
+	.name = "powersave",
+	.get_target_freq = devfreq_powersave_func,
+	.event_handler = devfreq_powersave_handler,
+};
+
+static int __init devfreq_powersave_init(void)
+{
+	return devfreq_add_governor(&devfreq_powersave);
+}
+subsys_initcall(devfreq_powersave_init);
+
+static void __exit devfreq_powersave_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_powersave);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_powersave_exit);
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
new file mode 100644
index 000000000..0720ba84c
--- /dev/null
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -0,0 +1,147 @@
+/*
+ *  linux/drivers/devfreq/governor_simpleondemand.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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/errno.h>
+#include <linux/module.h>
+#include <linux/devfreq.h>
+#include <linux/math64.h>
+#include "governor.h"
+
+/* Default constants for DevFreq-Simple-Ondemand (DFSO) */
+#define DFSO_UPTHRESHOLD	(90)
+#define DFSO_DOWNDIFFERENCTIAL	(5)
+static int devfreq_simple_ondemand_func(struct devfreq *df,
+					unsigned long *freq)
+{
+	struct devfreq_dev_status stat;
+	int err = df->profile->get_dev_status(df->dev.parent, &stat);
+	unsigned long long a, b;
+	unsigned int dfso_upthreshold = DFSO_UPTHRESHOLD;
+	unsigned int dfso_downdifferential = DFSO_DOWNDIFFERENCTIAL;
+	struct devfreq_simple_ondemand_data *data = df->data;
+	unsigned long max = (df->max_freq) ? df->max_freq : UINT_MAX;
+
+	if (err)
+		return err;
+
+	if (data) {
+		if (data->upthreshold)
+			dfso_upthreshold = data->upthreshold;
+		if (data->downdifferential)
+			dfso_downdifferential = data->downdifferential;
+	}
+	if (dfso_upthreshold > 100 ||
+	    dfso_upthreshold < dfso_downdifferential)
+		return -EINVAL;
+
+	/* Assume MAX if it is going to be divided by zero */
+	if (stat.total_time == 0) {
+		*freq = max;
+		return 0;
+	}
+
+	/* Prevent overflow */
+	if (stat.busy_time >= (1 << 24) || stat.total_time >= (1 << 24)) {
+		stat.busy_time >>= 7;
+		stat.total_time >>= 7;
+	}
+
+	/* Set MAX if it's busy enough */
+	if (stat.busy_time * 100 >
+	    stat.total_time * dfso_upthreshold) {
+		*freq = max;
+		return 0;
+	}
+
+	/* Set MAX if we do not know the initial frequency */
+	if (stat.current_frequency == 0) {
+		*freq = max;
+		return 0;
+	}
+
+	/* Keep the current frequency */
+	if (stat.busy_time * 100 >
+	    stat.total_time * (dfso_upthreshold - dfso_downdifferential)) {
+		*freq = stat.current_frequency;
+		return 0;
+	}
+
+	/* Set the desired frequency based on the load */
+	a = stat.busy_time;
+	a *= stat.current_frequency;
+	b = div_u64(a, stat.total_time);
+	b *= 100;
+	b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));
+	*freq = (unsigned long) b;
+
+	if (df->min_freq && *freq < df->min_freq)
+		*freq = df->min_freq;
+	if (df->max_freq && *freq > df->max_freq)
+		*freq = df->max_freq;
+
+	return 0;
+}
+
+static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		devfreq_monitor_start(devfreq);
+		break;
+
+	case DEVFREQ_GOV_STOP:
+		devfreq_monitor_stop(devfreq);
+		break;
+
+	case DEVFREQ_GOV_INTERVAL:
+		devfreq_interval_update(devfreq, (unsigned int *)data);
+		break;
+
+	case DEVFREQ_GOV_SUSPEND:
+		devfreq_monitor_suspend(devfreq);
+		break;
+
+	case DEVFREQ_GOV_RESUME:
+		devfreq_monitor_resume(devfreq);
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct devfreq_governor devfreq_simple_ondemand = {
+	.name = "simple_ondemand",
+	.get_target_freq = devfreq_simple_ondemand_func,
+	.event_handler = devfreq_simple_ondemand_handler,
+};
+
+static int __init devfreq_simple_ondemand_init(void)
+{
+	return devfreq_add_governor(&devfreq_simple_ondemand);
+}
+subsys_initcall(devfreq_simple_ondemand_init);
+
+static void __exit devfreq_simple_ondemand_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_simple_ondemand);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_simple_ondemand_exit);
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
new file mode 100644
index 000000000..35de6e83c
--- /dev/null
+++ b/drivers/devfreq/governor_userspace.c
@@ -0,0 +1,162 @@
+/*
+ *  linux/drivers/devfreq/governor_simpleondemand.c
+ *
+ *  Copyright (C) 2011 Samsung Electronics
+ *	MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * 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/slab.h>
+#include <linux/device.h>
+#include <linux/devfreq.h>
+#include <linux/pm.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include "governor.h"
+
+struct userspace_data {
+	unsigned long user_frequency;
+	bool valid;
+};
+
+static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq)
+{
+	struct userspace_data *data = df->data;
+
+	if (data->valid) {
+		unsigned long adjusted_freq = data->user_frequency;
+
+		if (df->max_freq && adjusted_freq > df->max_freq)
+			adjusted_freq = df->max_freq;
+
+		if (df->min_freq && adjusted_freq < df->min_freq)
+			adjusted_freq = df->min_freq;
+
+		*freq = adjusted_freq;
+	} else {
+		*freq = df->previous_freq; /* No user freq specified yet */
+	}
+	return 0;
+}
+
+static ssize_t store_freq(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	struct userspace_data *data;
+	unsigned long wanted;
+	int err = 0;
+
+
+	mutex_lock(&devfreq->lock);
+	data = devfreq->data;
+
+	sscanf(buf, "%lu", &wanted);
+	data->user_frequency = wanted;
+	data->valid = true;
+	err = update_devfreq(devfreq);
+	if (err == 0)
+		err = count;
+	mutex_unlock(&devfreq->lock);
+	return err;
+}
+
+static ssize_t show_freq(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	struct userspace_data *data;
+	int err = 0;
+
+	mutex_lock(&devfreq->lock);
+	data = devfreq->data;
+
+	if (data->valid)
+		err = sprintf(buf, "%lu\n", data->user_frequency);
+	else
+		err = sprintf(buf, "undefined\n");
+	mutex_unlock(&devfreq->lock);
+	return err;
+}
+
+static DEVICE_ATTR(set_freq, 0644, show_freq, store_freq);
+static struct attribute *dev_entries[] = {
+	&dev_attr_set_freq.attr,
+	NULL,
+};
+static struct attribute_group dev_attr_group = {
+	.name	= "userspace",
+	.attrs	= dev_entries,
+};
+
+static int userspace_init(struct devfreq *devfreq)
+{
+	int err = 0;
+	struct userspace_data *data = kzalloc(sizeof(struct userspace_data),
+					      GFP_KERNEL);
+
+	if (!data) {
+		err = -ENOMEM;
+		goto out;
+	}
+	data->valid = false;
+	devfreq->data = data;
+
+	err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group);
+out:
+	return err;
+}
+
+static void userspace_exit(struct devfreq *devfreq)
+{
+	sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
+	kfree(devfreq->data);
+	devfreq->data = NULL;
+}
+
+static int devfreq_userspace_handler(struct devfreq *devfreq,
+			unsigned int event, void *data)
+{
+	int ret = 0;
+
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		ret = userspace_init(devfreq);
+		break;
+	case DEVFREQ_GOV_STOP:
+		userspace_exit(devfreq);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_userspace = {
+	.name = "userspace",
+	.get_target_freq = devfreq_userspace_func,
+	.event_handler = devfreq_userspace_handler,
+};
+
+static int __init devfreq_userspace_init(void)
+{
+	return devfreq_add_governor(&devfreq_userspace);
+}
+subsys_initcall(devfreq_userspace_init);
+
+static void __exit devfreq_userspace_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_userspace);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_userspace_exit);
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
new file mode 100644
index 000000000..13a1a6e81
--- /dev/null
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -0,0 +1,785 @@
+/*
+ * A devfreq driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved.
+ * Copyright (C) 2014 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/devfreq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/reset.h>
+
+#include "governor.h"
+
+#define ACTMON_GLB_STATUS					0x0
+#define ACTMON_GLB_PERIOD_CTRL					0x4
+
+#define ACTMON_DEV_CTRL						0x0
+#define ACTMON_DEV_CTRL_K_VAL_SHIFT				10
+#define ACTMON_DEV_CTRL_ENB_PERIODIC				BIT(18)
+#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN			BIT(20)
+#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN			BIT(21)
+#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT	23
+#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT	26
+#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN		BIT(29)
+#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN		BIT(30)
+#define ACTMON_DEV_CTRL_ENB					BIT(31)
+
+#define ACTMON_DEV_UPPER_WMARK					0x4
+#define ACTMON_DEV_LOWER_WMARK					0x8
+#define ACTMON_DEV_INIT_AVG					0xc
+#define ACTMON_DEV_AVG_UPPER_WMARK				0x10
+#define ACTMON_DEV_AVG_LOWER_WMARK				0x14
+#define ACTMON_DEV_COUNT_WEIGHT					0x18
+#define ACTMON_DEV_AVG_COUNT					0x20
+#define ACTMON_DEV_INTR_STATUS					0x24
+
+#define ACTMON_INTR_STATUS_CLEAR				0xffffffff
+
+#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER			BIT(31)
+#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER			BIT(30)
+
+#define ACTMON_ABOVE_WMARK_WINDOW				1
+#define ACTMON_BELOW_WMARK_WINDOW				3
+#define ACTMON_BOOST_FREQ_STEP					16000
+
+/*
+ * Activity counter is incremented every 256 memory transactions, and each
+ * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is
+ * 4 * 256 = 1024.
+ */
+#define ACTMON_COUNT_WEIGHT					0x400
+
+/*
+ * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which
+ * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128
+ */
+#define ACTMON_AVERAGE_WINDOW_LOG2			6
+#define ACTMON_SAMPLING_PERIOD				12 /* ms */
+#define ACTMON_DEFAULT_AVG_BAND				6  /* 1/10 of % */
+
+#define KHZ							1000
+
+/* Assume that the bus is saturated if the utilization is 25% */
+#define BUS_SATURATION_RATIO					25
+
+/**
+ * struct tegra_devfreq_device_config - configuration specific to an ACTMON
+ * device
+ *
+ * Coefficients and thresholds are percentages unless otherwise noted
+ */
+struct tegra_devfreq_device_config {
+	u32		offset;
+	u32		irq_mask;
+
+	/* Factors applied to boost_freq every consecutive watermark breach */
+	unsigned int	boost_up_coeff;
+	unsigned int	boost_down_coeff;
+
+	/* Define the watermark bounds when applied to the current avg */
+	unsigned int	boost_up_threshold;
+	unsigned int	boost_down_threshold;
+
+	/*
+	 * Threshold of activity (cycles) below which the CPU frequency isn't
+	 * to be taken into account. This is to avoid increasing the EMC
+	 * frequency when the CPU is very busy but not accessing the bus often.
+	 */
+	u32		avg_dependency_threshold;
+};
+
+enum tegra_actmon_device {
+	MCALL = 0,
+	MCCPU,
+};
+
+static struct tegra_devfreq_device_config actmon_device_configs[] = {
+	{
+		/* MCALL: All memory accesses (including from the CPUs) */
+		.offset = 0x1c0,
+		.irq_mask = 1 << 26,
+		.boost_up_coeff = 200,
+		.boost_down_coeff = 50,
+		.boost_up_threshold = 60,
+		.boost_down_threshold = 40,
+	},
+	{
+		/* MCCPU: memory accesses from the CPUs */
+		.offset = 0x200,
+		.irq_mask = 1 << 25,
+		.boost_up_coeff = 800,
+		.boost_down_coeff = 90,
+		.boost_up_threshold = 27,
+		.boost_down_threshold = 10,
+		.avg_dependency_threshold = 50000,
+	},
+};
+
+/**
+ * struct tegra_devfreq_device - state specific to an ACTMON device
+ *
+ * Frequencies are in kHz.
+ */
+struct tegra_devfreq_device {
+	const struct tegra_devfreq_device_config *config;
+	void __iomem *regs;
+	spinlock_t lock;
+
+	/* Average event count sampled in the last interrupt */
+	u32 avg_count;
+
+	/*
+	 * Extra frequency to increase the target by due to consecutive
+	 * watermark breaches.
+	 */
+	unsigned long boost_freq;
+
+	/* Optimal frequency calculated from the stats for this device */
+	unsigned long target_freq;
+};
+
+struct tegra_devfreq {
+	struct devfreq		*devfreq;
+
+	struct reset_control	*reset;
+	struct clk		*clock;
+	void __iomem		*regs;
+
+	struct clk		*emc_clock;
+	unsigned long		max_freq;
+	unsigned long		cur_freq;
+	struct notifier_block	rate_change_nb;
+
+	struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
+};
+
+struct tegra_actmon_emc_ratio {
+	unsigned long cpu_freq;
+	unsigned long emc_freq;
+};
+
+static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
+	{ 1400000, ULONG_MAX },
+	{ 1200000,    750000 },
+	{ 1100000,    600000 },
+	{ 1000000,    500000 },
+	{  800000,    375000 },
+	{  500000,    200000 },
+	{  250000,    100000 },
+};
+
+static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset)
+{
+	return readl(tegra->regs + offset);
+}
+
+static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset)
+{
+	writel(val, tegra->regs + offset);
+}
+
+static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset)
+{
+	return readl(dev->regs + offset);
+}
+
+static void device_writel(struct tegra_devfreq_device *dev, u32 val,
+			  u32 offset)
+{
+	writel(val, dev->regs + offset);
+}
+
+static unsigned long do_percent(unsigned long val, unsigned int pct)
+{
+	return val * pct / 100;
+}
+
+static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra,
+					   struct tegra_devfreq_device *dev)
+{
+	u32 avg = dev->avg_count;
+	u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
+	u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD;
+
+	device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK);
+
+	avg = max(dev->avg_count, band);
+	device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK);
+}
+
+static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
+				       struct tegra_devfreq_device *dev)
+{
+	u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
+
+	device_writel(dev, do_percent(val, dev->config->boost_up_threshold),
+		      ACTMON_DEV_UPPER_WMARK);
+
+	device_writel(dev, do_percent(val, dev->config->boost_down_threshold),
+		      ACTMON_DEV_LOWER_WMARK);
+}
+
+static void actmon_write_barrier(struct tegra_devfreq *tegra)
+{
+	/* ensure the update has reached the ACTMON */
+	wmb();
+	actmon_readl(tegra, ACTMON_GLB_STATUS);
+}
+
+static void actmon_isr_device(struct tegra_devfreq *tegra,
+			      struct tegra_devfreq_device *dev)
+{
+	unsigned long flags;
+	u32 intr_status, dev_ctrl;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT);
+	tegra_devfreq_update_avg_wmark(tegra, dev);
+
+	intr_status = device_readl(dev, ACTMON_DEV_INTR_STATUS);
+	dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL);
+
+	if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) {
+		/*
+		 * new_boost = min(old_boost * up_coef + step, max_freq)
+		 */
+		dev->boost_freq = do_percent(dev->boost_freq,
+					     dev->config->boost_up_coeff);
+		dev->boost_freq += ACTMON_BOOST_FREQ_STEP;
+
+		dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+
+		if (dev->boost_freq >= tegra->max_freq)
+			dev->boost_freq = tegra->max_freq;
+		else
+			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+	} else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {
+		/*
+		 * new_boost = old_boost * down_coef
+		 * or 0 if (old_boost * down_coef < step / 2)
+		 */
+		dev->boost_freq = do_percent(dev->boost_freq,
+					     dev->config->boost_down_coeff);
+
+		dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+
+		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1))
+			dev->boost_freq = 0;
+		else
+			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+	}
+
+	if (dev->config->avg_dependency_threshold) {
+		if (dev->avg_count >= dev->config->avg_dependency_threshold)
+			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		else if (dev->boost_freq == 0)
+			dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+	}
+
+	device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL);
+
+	device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
+
+	actmon_write_barrier(tegra);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+static irqreturn_t actmon_isr(int irq, void *data)
+{
+	struct tegra_devfreq *tegra = data;
+	bool handled = false;
+	unsigned int i;
+	u32 val;
+
+	val = actmon_readl(tegra, ACTMON_GLB_STATUS);
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		if (val & tegra->devices[i].config->irq_mask) {
+			actmon_isr_device(tegra, tegra->devices + i);
+			handled = true;
+		}
+	}
+
+	return handled ? IRQ_WAKE_THREAD : IRQ_NONE;
+}
+
+static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
+					    unsigned long cpu_freq)
+{
+	unsigned int i;
+	struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
+
+	for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
+		if (cpu_freq >= ratio->cpu_freq) {
+			if (ratio->emc_freq >= tegra->max_freq)
+				return tegra->max_freq;
+			else
+				return ratio->emc_freq;
+		}
+	}
+
+	return 0;
+}
+
+static void actmon_update_target(struct tegra_devfreq *tegra,
+				 struct tegra_devfreq_device *dev)
+{
+	unsigned long cpu_freq = 0;
+	unsigned long static_cpu_emc_freq = 0;
+	unsigned int avg_sustain_coef;
+	unsigned long flags;
+
+	if (dev->config->avg_dependency_threshold) {
+		cpu_freq = cpufreq_get(0);
+		static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
+	}
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
+	avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
+	dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef);
+	dev->target_freq += dev->boost_freq;
+
+	if (dev->avg_count >= dev->config->avg_dependency_threshold)
+		dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+static irqreturn_t actmon_thread_isr(int irq, void *data)
+{
+	struct tegra_devfreq *tegra = data;
+
+	mutex_lock(&tegra->devfreq->lock);
+	update_devfreq(tegra->devfreq);
+	mutex_unlock(&tegra->devfreq->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
+				       unsigned long action, void *ptr)
+{
+	struct clk_notifier_data *data = ptr;
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *dev;
+	unsigned int i;
+	unsigned long flags;
+
+	if (action != POST_RATE_CHANGE)
+		return NOTIFY_OK;
+
+	tegra = container_of(nb, struct tegra_devfreq, rate_change_nb);
+
+	tegra->cur_freq = data->new_rate / KHZ;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		dev = &tegra->devices[i];
+
+		spin_lock_irqsave(&dev->lock, flags);
+		tegra_devfreq_update_wmark(tegra, dev);
+		spin_unlock_irqrestore(&dev->lock, flags);
+	}
+
+	actmon_write_barrier(tegra);
+
+	return NOTIFY_OK;
+}
+
+static void tegra_actmon_enable_interrupts(struct tegra_devfreq *tegra)
+{
+	struct tegra_devfreq_device *dev;
+	u32 val;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		dev = &tegra->devices[i];
+
+		val = device_readl(dev, ACTMON_DEV_CTRL);
+		val |= ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN;
+		val |= ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
+		val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		val |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+
+		device_writel(dev, val, ACTMON_DEV_CTRL);
+	}
+
+	actmon_write_barrier(tegra);
+}
+
+static void tegra_actmon_disable_interrupts(struct tegra_devfreq *tegra)
+{
+	struct tegra_devfreq_device *dev;
+	u32 val;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		dev = &tegra->devices[i];
+
+		val = device_readl(dev, ACTMON_DEV_CTRL);
+		val &= ~ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN;
+		val &= ~ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
+		val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+
+		device_writel(dev, val, ACTMON_DEV_CTRL);
+	}
+
+	actmon_write_barrier(tegra);
+}
+
+static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
+					  struct tegra_devfreq_device *dev)
+{
+	u32 val = 0;
+
+	dev->target_freq = tegra->cur_freq;
+
+	dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
+	device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG);
+
+	tegra_devfreq_update_avg_wmark(tegra, dev);
+	tegra_devfreq_update_wmark(tegra, dev);
+
+	device_writel(dev, ACTMON_COUNT_WEIGHT, ACTMON_DEV_COUNT_WEIGHT);
+	device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
+
+	val |= ACTMON_DEV_CTRL_ENB_PERIODIC;
+	val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1)
+		<< ACTMON_DEV_CTRL_K_VAL_SHIFT;
+	val |= (ACTMON_BELOW_WMARK_WINDOW - 1)
+		<< ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT;
+	val |= (ACTMON_ABOVE_WMARK_WINDOW - 1)
+		<< ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT;
+	val |= ACTMON_DEV_CTRL_ENB;
+
+	device_writel(dev, val, ACTMON_DEV_CTRL);
+
+	actmon_write_barrier(tegra);
+}
+
+static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
+				u32 flags)
+{
+	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
+	struct dev_pm_opp *opp;
+	unsigned long rate = *freq * KHZ;
+
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, &rate, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "Failed to find opp for %lu KHz\n", *freq);
+		return PTR_ERR(opp);
+	}
+	rate = dev_pm_opp_get_freq(opp);
+	rcu_read_unlock();
+
+	clk_set_min_rate(tegra->emc_clock, rate);
+	clk_set_rate(tegra->emc_clock, 0);
+
+	return 0;
+}
+
+static int tegra_devfreq_get_dev_status(struct device *dev,
+					struct devfreq_dev_status *stat)
+{
+	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
+	struct tegra_devfreq_device *actmon_dev;
+
+	stat->current_frequency = tegra->cur_freq;
+
+	/* To be used by the tegra governor */
+	stat->private_data = tegra;
+
+	/* The below are to be used by the other governors */
+
+	actmon_dev = &tegra->devices[MCALL];
+
+	/* Number of cycles spent on memory access */
+	stat->busy_time = device_readl(actmon_dev, ACTMON_DEV_AVG_COUNT);
+
+	/* The bus can be considered to be saturated way before 100% */
+	stat->busy_time *= 100 / BUS_SATURATION_RATIO;
+
+	/* Number of cycles in a sampling period */
+	stat->total_time = ACTMON_SAMPLING_PERIOD * tegra->cur_freq;
+
+	stat->busy_time = min(stat->busy_time, stat->total_time);
+
+	return 0;
+}
+
+static struct devfreq_dev_profile tegra_devfreq_profile = {
+	.polling_ms	= 0,
+	.target		= tegra_devfreq_target,
+	.get_dev_status	= tegra_devfreq_get_dev_status,
+};
+
+static int tegra_governor_get_target(struct devfreq *devfreq,
+				     unsigned long *freq)
+{
+	struct devfreq_dev_status stat;
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *dev;
+	unsigned long target_freq = 0;
+	unsigned int i;
+	int err;
+
+	err = devfreq->profile->get_dev_status(devfreq->dev.parent, &stat);
+	if (err)
+		return err;
+
+	tegra = stat.private_data;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		dev = &tegra->devices[i];
+
+		actmon_update_target(tegra, dev);
+
+		target_freq = max(target_freq, dev->target_freq);
+	}
+
+	*freq = target_freq;
+
+	return 0;
+}
+
+static int tegra_governor_event_handler(struct devfreq *devfreq,
+					unsigned int event, void *data)
+{
+	struct tegra_devfreq *tegra;
+	int ret = 0;
+
+	tegra = dev_get_drvdata(devfreq->dev.parent);
+
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		devfreq_monitor_start(devfreq);
+		tegra_actmon_enable_interrupts(tegra);
+		break;
+
+	case DEVFREQ_GOV_STOP:
+		tegra_actmon_disable_interrupts(tegra);
+		devfreq_monitor_stop(devfreq);
+		break;
+
+	case DEVFREQ_GOV_SUSPEND:
+		tegra_actmon_disable_interrupts(tegra);
+		devfreq_monitor_suspend(devfreq);
+		break;
+
+	case DEVFREQ_GOV_RESUME:
+		devfreq_monitor_resume(devfreq);
+		tegra_actmon_enable_interrupts(tegra);
+		break;
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor tegra_devfreq_governor = {
+	.name = "tegra_actmon",
+	.get_target_freq = tegra_governor_get_target,
+	.event_handler = tegra_governor_event_handler,
+};
+
+static int tegra_devfreq_probe(struct platform_device *pdev)
+{
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *dev;
+	struct resource *res;
+	unsigned int i;
+	unsigned long rate;
+	int irq;
+	int err;
+
+	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
+	if (!tegra)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tegra->regs))
+		return PTR_ERR(tegra->regs);
+
+	tegra->reset = devm_reset_control_get(&pdev->dev, "actmon");
+	if (IS_ERR(tegra->reset)) {
+		dev_err(&pdev->dev, "Failed to get reset\n");
+		return PTR_ERR(tegra->reset);
+	}
+
+	tegra->clock = devm_clk_get(&pdev->dev, "actmon");
+	if (IS_ERR(tegra->clock)) {
+		dev_err(&pdev->dev, "Failed to get actmon clock\n");
+		return PTR_ERR(tegra->clock);
+	}
+
+	tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
+	if (IS_ERR(tegra->emc_clock)) {
+		dev_err(&pdev->dev, "Failed to get emc clock\n");
+		return PTR_ERR(tegra->emc_clock);
+	}
+
+	clk_set_rate(tegra->emc_clock, ULONG_MAX);
+
+	tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb;
+	err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb);
+	if (err) {
+		dev_err(&pdev->dev,
+			"Failed to register rate change notifier\n");
+		return err;
+	}
+
+	reset_control_assert(tegra->reset);
+
+	err = clk_prepare_enable(tegra->clock);
+	if (err) {
+		dev_err(&pdev->dev,
+			"Failed to prepare and enable ACTMON clock\n");
+		return err;
+	}
+
+	reset_control_deassert(tegra->reset);
+
+	tegra->max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX) / KHZ;
+	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
+
+	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
+		      ACTMON_GLB_PERIOD_CTRL);
+
+	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
+		dev = tegra->devices + i;
+		dev->config = actmon_device_configs + i;
+		dev->regs = tegra->regs + dev->config->offset;
+		spin_lock_init(&dev->lock);
+
+		tegra_actmon_configure_device(tegra, dev);
+	}
+
+	for (rate = 0; rate <= tegra->max_freq * KHZ; rate++) {
+		rate = clk_round_rate(tegra->emc_clock, rate);
+		dev_pm_opp_add(&pdev->dev, rate, 0);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(&pdev->dev, "Failed to get IRQ\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, tegra);
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr,
+					actmon_thread_isr, IRQF_SHARED,
+					"tegra-devfreq", tegra);
+	if (err) {
+		dev_err(&pdev->dev, "Interrupt request failed\n");
+		return err;
+	}
+
+	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
+	tegra->devfreq = devm_devfreq_add_device(&pdev->dev,
+						 &tegra_devfreq_profile,
+						 "tegra_actmon",
+						 NULL);
+
+	return 0;
+}
+
+static int tegra_devfreq_remove(struct platform_device *pdev)
+{
+	struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
+	int irq = platform_get_irq(pdev, 0);
+	u32 val;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
+		val = device_readl(&tegra->devices[i], ACTMON_DEV_CTRL);
+		val &= ~ACTMON_DEV_CTRL_ENB;
+		device_writel(&tegra->devices[i], val, ACTMON_DEV_CTRL);
+	}
+
+	actmon_write_barrier(tegra);
+
+	devm_free_irq(&pdev->dev, irq, tegra);
+
+	clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
+
+	clk_disable_unprepare(tegra->clock);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_devfreq_of_match[] = {
+	{ .compatible = "nvidia,tegra124-actmon" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);
+
+static struct platform_driver tegra_devfreq_driver = {
+	.probe	= tegra_devfreq_probe,
+	.remove	= tegra_devfreq_remove,
+	.driver = {
+		.name = "tegra-devfreq",
+		.of_match_table = tegra_devfreq_of_match,
+	},
+};
+
+static int __init tegra_devfreq_init(void)
+{
+	int ret = 0;
+
+	ret = devfreq_add_governor(&tegra_devfreq_governor);
+	if (ret) {
+		pr_err("%s: failed to add governor: %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = platform_driver_register(&tegra_devfreq_driver);
+	if (ret)
+		devfreq_remove_governor(&tegra_devfreq_governor);
+
+	return ret;
+}
+module_init(tegra_devfreq_init)
+
+static void __exit tegra_devfreq_exit(void)
+{
+	int ret = 0;
+
+	platform_driver_unregister(&tegra_devfreq_driver);
+
+	ret = devfreq_remove_governor(&tegra_devfreq_governor);
+	if (ret)
+		pr_err("%s: failed to remove governor: %d\n", __func__, ret);
+}
+module_exit(tegra_devfreq_exit)
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Tegra devfreq driver");
+MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>");