Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

9 files changed, 2249 insertions, 0 deletions

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
new file mode 100644
index 00000000..464fa214
--- /dev/null
+++ b/drivers/devfreq/Kconfig
@@ -0,0 +1,81 @@
+menuconfig PM_DEVFREQ
+	bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
+	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
+	  responsiblity 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
+	bool "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
+	bool "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
+	bool "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
+	bool "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 || CPU_EXYNOS4212 || CPU_EXYNOS4412
+	select ARCH_HAS_OPP
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	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.
+	  To operate with optimal voltages, ASV support is required
+	  (CONFIG_EXYNOS_ASV).
+
+endif # PM_DEVFREQ
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
new file mode 100644
index 00000000..8c464234
--- /dev/null
+++ b/drivers/devfreq/Makefile
@@ -0,0 +1,8 @@
+obj-$(CONFIG_PM_DEVFREQ)	+= devfreq.o
+obj-$(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)	+= exynos4_bus.o
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
new file mode 100644
index 00000000..70c31d43
--- /dev/null
+++ b/drivers/devfreq/devfreq.c
@@ -0,0 +1,710 @@
+/*
+ * 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/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"
+
+struct class *devfreq_class;
+
+/*
+ * devfreq_work periodically monitors every registered device.
+ * The minimum polling interval is one jiffy. The polling interval is
+ * determined by the minimum polling period among all polling devfreq
+ * devices. The resolution of polling interval is one jiffy.
+ */
+static bool polling;
+static struct workqueue_struct *devfreq_wq;
+static struct delayed_work devfreq_work;
+
+/* wait removing if this is to be removed */
+static struct devfreq *wait_remove_device;
+
+/* 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);
+}
+
+/**
+ * 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;
+	}
+
+	/* 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;
+
+	devfreq->previous_freq = freq;
+	return err;
+}
+
+/**
+ * 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 device.
+ * @devfreq:	the devfreq struct
+ * @skip:	skip calling device_unregister().
+ *
+ * Note that the caller should lock devfreq->lock before calling
+ * this. _remove_devfreq() will unlock it and free devfreq
+ * internally. devfreq_list_lock should be locked by the caller
+ * as well (not relased at return)
+ *
+ * Lock usage:
+ * devfreq->lock: locked before call.
+ *		  unlocked at return (and freed)
+ * devfreq_list_lock: locked before call.
+ *		      kept locked at return.
+ *		      if devfreq is centrally polled.
+ *
+ * Freed memory:
+ * devfreq
+ */
+static void _remove_devfreq(struct devfreq *devfreq, bool skip)
+{
+	if (!mutex_is_locked(&devfreq->lock)) {
+		WARN(true, "devfreq->lock must be locked by the caller.\n");
+		return;
+	}
+	if (!devfreq->governor->no_central_polling &&
+	    !mutex_is_locked(&devfreq_list_lock)) {
+		WARN(true, "devfreq_list_lock must be locked by the caller.\n");
+		return;
+	}
+
+	if (devfreq->being_removed)
+		return;
+
+	devfreq->being_removed = true;
+
+	if (devfreq->profile->exit)
+		devfreq->profile->exit(devfreq->dev.parent);
+
+	if (devfreq->governor->exit)
+		devfreq->governor->exit(devfreq);
+
+	if (!skip && get_device(&devfreq->dev)) {
+		device_unregister(&devfreq->dev);
+		put_device(&devfreq->dev);
+	}
+
+	if (!devfreq->governor->no_central_polling)
+		list_del(&devfreq->node);
+
+	mutex_unlock(&devfreq->lock);
+	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.
+ * Note that devfreq_dev_release() could be called by _remove_devfreq() as
+ * well as by others unregistering the device.
+ */
+static void devfreq_dev_release(struct device *dev)
+{
+	struct devfreq *devfreq = to_devfreq(dev);
+	bool central_polling = !devfreq->governor->no_central_polling;
+
+	/*
+	 * If devfreq_dev_release() was called by device_unregister() of
+	 * _remove_devfreq(), we cannot mutex_lock(&devfreq->lock) and
+	 * being_removed is already set. This also partially checks the case
+	 * where devfreq_dev_release() is called from a thread other than
+	 * the one called _remove_devfreq(); however, this case is
+	 * dealt completely with another following being_removed check.
+	 *
+	 * Because being_removed is never being
+	 * unset, we do not need to worry about race conditions on
+	 * being_removed.
+	 */
+	if (devfreq->being_removed)
+		return;
+
+	if (central_polling)
+		mutex_lock(&devfreq_list_lock);
+
+	mutex_lock(&devfreq->lock);
+
+	/*
+	 * Check being_removed flag again for the case where
+	 * devfreq_dev_release() was called in a thread other than the one
+	 * possibly called _remove_devfreq().
+	 */
+	if (devfreq->being_removed) {
+		mutex_unlock(&devfreq->lock);
+		goto out;
+	}
+
+	/* devfreq->lock is unlocked and removed in _removed_devfreq() */
+	_remove_devfreq(devfreq, true);
+
+out:
+	if (central_polling)
+		mutex_unlock(&devfreq_list_lock);
+}
+
+/**
+ * devfreq_monitor() - Periodically poll devfreq objects.
+ * @work: the work struct used to run devfreq_monitor periodically.
+ *
+ */
+static void devfreq_monitor(struct work_struct *work)
+{
+	static unsigned long last_polled_at;
+	struct devfreq *devfreq, *tmp;
+	int error;
+	unsigned long jiffies_passed;
+	unsigned long next_jiffies = ULONG_MAX, now = jiffies;
+	struct device *dev;
+
+	/* Initially last_polled_at = 0, polling every device at bootup */
+	jiffies_passed = now - last_polled_at;
+	last_polled_at = now;
+	if (jiffies_passed == 0)
+		jiffies_passed = 1;
+
+	mutex_lock(&devfreq_list_lock);
+	list_for_each_entry_safe(devfreq, tmp, &devfreq_list, node) {
+		mutex_lock(&devfreq->lock);
+		dev = devfreq->dev.parent;
+
+		/* Do not remove tmp for a while */
+		wait_remove_device = tmp;
+
+		if (devfreq->governor->no_central_polling ||
+		    devfreq->next_polling == 0) {
+			mutex_unlock(&devfreq->lock);
+			continue;
+		}
+		mutex_unlock(&devfreq_list_lock);
+
+		/*
+		 * Reduce more next_polling if devfreq_wq took an extra
+		 * delay. (i.e., CPU has been idled.)
+		 */
+		if (devfreq->next_polling <= jiffies_passed) {
+			error = update_devfreq(devfreq);
+
+			/* Remove a devfreq with an error. */
+			if (error && error != -EAGAIN) {
+
+				dev_err(dev, "Due to update_devfreq error(%d), devfreq(%s) is removed from the device\n",
+					error, devfreq->governor->name);
+
+				/*
+				 * Unlock devfreq before locking the list
+				 * in order to avoid deadlock with
+				 * find_device_devfreq or others
+				 */
+				mutex_unlock(&devfreq->lock);
+				mutex_lock(&devfreq_list_lock);
+				/* Check if devfreq is already removed */
+				if (IS_ERR(find_device_devfreq(dev)))
+					continue;
+				mutex_lock(&devfreq->lock);
+				/* This unlocks devfreq->lock and free it */
+				_remove_devfreq(devfreq, false);
+				continue;
+			}
+			devfreq->next_polling = devfreq->polling_jiffies;
+		} else {
+			devfreq->next_polling -= jiffies_passed;
+		}
+
+		if (devfreq->next_polling)
+			next_jiffies = (next_jiffies > devfreq->next_polling) ?
+					devfreq->next_polling : next_jiffies;
+
+		mutex_unlock(&devfreq->lock);
+		mutex_lock(&devfreq_list_lock);
+	}
+	wait_remove_device = NULL;
+	mutex_unlock(&devfreq_list_lock);
+
+	if (next_jiffies > 0 && next_jiffies < ULONG_MAX) {
+		polling = true;
+		queue_delayed_work(devfreq_wq, &devfreq_work, next_jiffies);
+	} else {
+		polling = false;
+	}
+}
+
+/**
+ * devfreq_add_device() - Add devfreq feature to the device
+ * @dev:	the device to add devfreq feature.
+ * @profile:	device-specific profile to run devfreq.
+ * @governor:	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 struct devfreq_governor *governor,
+				   void *data)
+{
+	struct devfreq *devfreq;
+	int err = 0;
+
+	if (!dev || !profile || !governor) {
+		dev_err(dev, "%s: Invalid parameters.\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+
+	if (!governor->no_central_polling) {
+		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;
+	devfreq->governor = governor;
+	devfreq->previous_freq = profile->initial_freq;
+	devfreq->data = data;
+	devfreq->next_polling = devfreq->polling_jiffies
+			      = msecs_to_jiffies(devfreq->profile->polling_ms);
+	devfreq->nb.notifier_call = devfreq_notifier_call;
+
+	dev_set_name(&devfreq->dev, dev_name(dev));
+	err = device_register(&devfreq->dev);
+	if (err) {
+		put_device(&devfreq->dev);
+		goto err_dev;
+	}
+
+	if (governor->init)
+		err = governor->init(devfreq);
+	if (err)
+		goto err_init;
+
+	mutex_unlock(&devfreq->lock);
+
+	if (governor->no_central_polling)
+		goto out;
+
+	mutex_lock(&devfreq_list_lock);
+
+	list_add(&devfreq->node, &devfreq_list);
+
+	if (devfreq_wq && devfreq->next_polling && !polling) {
+		polling = true;
+		queue_delayed_work(devfreq_wq, &devfreq_work,
+				   devfreq->next_polling);
+	}
+	mutex_unlock(&devfreq_list_lock);
+out:
+	return devfreq;
+
+err_init:
+	device_unregister(&devfreq->dev);
+err_dev:
+	mutex_unlock(&devfreq->lock);
+	kfree(devfreq);
+err_out:
+	return ERR_PTR(err);
+}
+
+/**
+ * devfreq_remove_device() - Remove devfreq feature from a device.
+ * @devfreq	the devfreq instance to be removed
+ */
+int devfreq_remove_device(struct devfreq *devfreq)
+{
+	bool central_polling;
+
+	if (!devfreq)
+		return -EINVAL;
+
+	central_polling = !devfreq->governor->no_central_polling;
+
+	if (central_polling) {
+		mutex_lock(&devfreq_list_lock);
+		while (wait_remove_device == devfreq) {
+			mutex_unlock(&devfreq_list_lock);
+			schedule();
+			mutex_lock(&devfreq_list_lock);
+		}
+	}
+
+	mutex_lock(&devfreq->lock);
+	_remove_devfreq(devfreq, false); /* it unlocks devfreq->lock */
+
+	if (central_polling)
+		mutex_unlock(&devfreq_list_lock);
+
+	return 0;
+}
+
+static ssize_t show_governor(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
+}
+
+static ssize_t show_freq(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
+}
+
+static ssize_t show_polling_interval(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms);
+}
+
+static ssize_t store_polling_interval(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct devfreq *df = to_devfreq(dev);
+	unsigned int value;
+	int ret;
+
+	ret = sscanf(buf, "%u", &value);
+	if (ret != 1)
+		goto out;
+
+	mutex_lock(&df->lock);
+	df->profile->polling_ms = value;
+	df->next_polling = df->polling_jiffies
+			 = msecs_to_jiffies(value);
+	mutex_unlock(&df->lock);
+
+	ret = count;
+
+	if (df->governor->no_central_polling)
+		goto out;
+
+	mutex_lock(&devfreq_list_lock);
+	if (df->next_polling > 0 && !polling) {
+		polling = true;
+		queue_delayed_work(devfreq_wq, &devfreq_work,
+				   df->next_polling);
+	}
+	mutex_unlock(&devfreq_list_lock);
+out:
+	return ret;
+}
+
+static ssize_t show_central_polling(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n",
+		       !to_devfreq(dev)->governor->no_central_polling);
+}
+
+static ssize_t store_min_freq(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)
+		goto out;
+
+	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);
+out:
+	return ret;
+}
+
+static ssize_t show_min_freq(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq);
+}
+
+static ssize_t store_max_freq(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)
+		goto out;
+
+	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);
+out:
+	return ret;
+}
+
+static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq);
+}
+
+static struct device_attribute devfreq_attrs[] = {
+	__ATTR(governor, S_IRUGO, show_governor, NULL),
+	__ATTR(cur_freq, S_IRUGO, show_freq, NULL),
+	__ATTR(central_polling, S_IRUGO, show_central_polling, NULL),
+	__ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval,
+	       store_polling_interval),
+	__ATTR(min_freq, S_IRUGO | S_IWUSR, show_min_freq, store_min_freq),
+	__ATTR(max_freq, S_IRUGO | S_IWUSR, show_max_freq, store_max_freq),
+	{ },
+};
+
+/**
+ * devfreq_start_polling() - Initialize data structure for devfreq framework and
+ *			   start polling registered devfreq devices.
+ */
+static int __init devfreq_start_polling(void)
+{
+	mutex_lock(&devfreq_list_lock);
+	polling = false;
+	devfreq_wq = create_freezable_workqueue("devfreq_wq");
+	INIT_DELAYED_WORK_DEFERRABLE(&devfreq_work, devfreq_monitor);
+	mutex_unlock(&devfreq_list_lock);
+
+	devfreq_monitor(&devfreq_work.work);
+	return 0;
+}
+late_initcall(devfreq_start_polling);
+
+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_class->dev_attrs = devfreq_attrs;
+	return 0;
+}
+subsys_initcall(devfreq_init);
+
+static void __exit devfreq_exit(void)
+{
+	class_destroy(devfreq_class);
+}
+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.
+ *
+ */
+struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq,
+				    u32 flags)
+{
+	struct opp *opp;
+
+	if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
+		/* The freq is an upper bound. opp should be lower */
+		opp = opp_find_freq_floor(dev, freq);
+
+		/* If not available, use the closest opp */
+		if (opp == ERR_PTR(-ENODEV))
+			opp = opp_find_freq_ceil(dev, freq);
+	} else {
+		/* The freq is an lower bound. opp should be higher */
+		opp = opp_find_freq_ceil(dev, freq);
+
+		/* If not available, use the closest opp */
+		if (opp == ERR_PTR(-ENODEV))
+			opp = opp_find_freq_floor(dev, freq);
+	}
+
+	return 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 = opp_get_notifier(dev);
+
+	if (IS_ERR(nh))
+		return PTR_ERR(nh);
+	return srcu_notifier_chain_register(nh, &devfreq->nb);
+}
+
+/**
+ * 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 = opp_get_notifier(dev);
+
+	if (IS_ERR(nh))
+		return PTR_ERR(nh);
+	return srcu_notifier_chain_unregister(nh, &devfreq->nb);
+}
+
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("devfreq class support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/devfreq/exynos4_bus.c b/drivers/devfreq/exynos4_bus.c
new file mode 100644
index 00000000..88ddc77a
--- /dev/null
+++ b/drivers/devfreq/exynos4_bus.c
@@ -0,0 +1,1132 @@
+/* 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/opp.h>
+#include <linux/devfreq.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/module.h>
+
+/* Exynos4 ASV has been in the mailing list, but not upstreamed, yet. */
+#ifdef CONFIG_EXYNOS_ASV
+extern unsigned int exynos_result_of_asv;
+#endif
+
+#include <mach/regs-clock.h>
+
+#include <plat/map-s5p.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 ppmu_counter {
+	PPMU_PMNCNT0 = 0,
+	PPMU_PMCCNT1,
+	PPMU_PMNCNT2,
+	PPMU_PMNCNT3,
+	PPMU_PMNCNT_MAX,
+};
+struct exynos4_ppmu {
+	void __iomem *hw_base;
+	unsigned int ccnt;
+	unsigned int event;
+	unsigned int count[PPMU_PMNCNT_MAX];
+	bool ccnt_overflow;
+	bool count_overflow[PPMU_PMNCNT_MAX];
+};
+
+enum busclk_level_idx {
+	LV_0 = 0,
+	LV_1,
+	LV_2,
+	LV_3,
+	LV_4,
+	_LV_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_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 opp *curr_opp;
+	struct exynos4_ppmu dmc[2];
+
+	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];
+};
+
+struct bus_opp_table {
+	unsigned int idx;
+	unsigned long clk;
+	unsigned long volt;
+};
+
+/* 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 exynox4x12 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 opp *opp)
+{
+	unsigned int index;
+	unsigned int tmp;
+
+	for (index = LV_0; index < EX4210_LV_NUM; index++)
+		if (opp_get_freq(opp) == 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 opp *opp)
+{
+	unsigned int index;
+	unsigned int tmp;
+
+	for (index = LV_0; index < EX4x12_LV_NUM; index++)
+		if (opp_get_freq(opp) == 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 void busfreq_mon_reset(struct busfreq_data *data)
+{
+	unsigned int i;
+
+	for (i = 0; i < 2; i++) {
+		void __iomem *ppmu_base = data->dmc[i].hw_base;
+
+		/* Reset PPMU */
+		__raw_writel(0x8000000f, ppmu_base + 0xf010);
+		__raw_writel(0x8000000f, ppmu_base + 0xf050);
+		__raw_writel(0x6, ppmu_base + 0xf000);
+		__raw_writel(0x0, ppmu_base + 0xf100);
+
+		/* Set PPMU Event */
+		data->dmc[i].event = 0x6;
+		__raw_writel(((data->dmc[i].event << 12) | 0x1),
+			     ppmu_base + 0xfc);
+
+		/* Start PPMU */
+		__raw_writel(0x1, ppmu_base + 0xf000);
+	}
+}
+
+static void exynos4_read_ppmu(struct busfreq_data *data)
+{
+	int i, j;
+
+	for (i = 0; i < 2; i++) {
+		void __iomem *ppmu_base = data->dmc[i].hw_base;
+		u32 overflow;
+
+		/* Stop PPMU */
+		__raw_writel(0x0, ppmu_base + 0xf000);
+
+		/* Update local data from PPMU */
+		overflow = __raw_readl(ppmu_base + 0xf050);
+
+		data->dmc[i].ccnt = __raw_readl(ppmu_base + 0xf100);
+		data->dmc[i].ccnt_overflow = overflow & (1 << 31);
+
+		for (j = 0; j < PPMU_PMNCNT_MAX; j++) {
+			data->dmc[i].count[j] = __raw_readl(
+					ppmu_base + (0xf110 + (0x10 * j)));
+			data->dmc[i].count_overflow[j] = overflow & (1 << j);
+		}
+	}
+
+	busfreq_mon_reset(data);
+}
+
+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 opp *opp,
+			       struct opp *oldopp)
+{
+	int err = 0, tmp;
+	unsigned long volt = opp_get_voltage(opp);
+
+	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(opp_get_freq(opp));
+		if (tmp < 0) {
+			err = tmp;
+			regulator_set_voltage(data->vdd_mif,
+					      opp_get_voltage(oldopp),
+					      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,
+					      opp_get_voltage(oldopp),
+					      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 opp *opp = devfreq_recommended_opp(dev, _freq, flags);
+	unsigned long freq = opp_get_freq(opp);
+	unsigned long old_freq = opp_get_freq(data->curr_opp);
+
+	if (IS_ERR(opp))
+		return PTR_ERR(opp);
+
+	if (old_freq == freq)
+		return 0;
+
+	dev_dbg(dev, "targetting %lukHz %luuV\n", freq, opp_get_voltage(opp));
+
+	mutex_lock(&data->lock);
+
+	if (data->disabled)
+		goto out;
+
+	if (old_freq < freq)
+		err = exynos4_bus_setvolt(data, opp, data->curr_opp);
+	if (err)
+		goto out;
+
+	if (old_freq != freq) {
+		switch (data->type) {
+		case TYPE_BUSF_EXYNOS4210:
+			err = exynos4210_set_busclk(data, opp);
+			break;
+		case TYPE_BUSF_EXYNOS4x12:
+			err = exynos4x12_set_busclk(data, opp);
+			break;
+		default:
+			err = -EINVAL;
+		}
+	}
+	if (err)
+		goto out;
+
+	if (old_freq > freq)
+		err = exynos4_bus_setvolt(data, opp, data->curr_opp);
+	if (err)
+		goto out;
+
+	data->curr_opp = opp;
+out:
+	mutex_unlock(&data->lock);
+	return err;
+}
+
+static int exynos4_get_busier_dmc(struct busfreq_data *data)
+{
+	u64 p0 = data->dmc[0].count[0];
+	u64 p1 = data->dmc[1].count[0];
+
+	p0 *= data->dmc[1].ccnt;
+	p1 *= data->dmc[0].ccnt;
+
+	if (data->dmc[1].ccnt == 0)
+		return 0;
+
+	if (p0 > p1)
+		return 0;
+	return 1;
+}
+
+static int exynos4_bus_get_dev_status(struct device *dev,
+				      struct devfreq_dev_status *stat)
+{
+	struct busfreq_data *data = dev_get_drvdata(dev);
+	int busier_dmc;
+	int cycles_x2 = 2; /* 2 x cycles */
+	void __iomem *addr;
+	u32 timing;
+	u32 memctrl;
+
+	exynos4_read_ppmu(data);
+	busier_dmc = exynos4_get_busier_dmc(data);
+	stat->current_frequency = opp_get_freq(data->curr_opp);
+
+	if (busier_dmc)
+		addr = S5P_VA_DMC1;
+	else
+		addr = S5P_VA_DMC0;
+
+	memctrl = __raw_readl(addr + 0x04); /* one of DDR2/3/LPDDR2 */
+	timing = __raw_readl(addr + 0x38); /* CL or WL/RL values */
+
+	switch ((memctrl >> 8) & 0xf) {
+	case 0x4: /* DDR2 */
+		cycles_x2 = ((timing >> 16) & 0xf) * 2;
+		break;
+	case 0x5: /* LPDDR2 */
+	case 0x6: /* DDR3 */
+		cycles_x2 = ((timing >> 8) & 0xf) + ((timing >> 0) & 0xf);
+		break;
+	default:
+		pr_err("%s: Unknown Memory Type(%d).\n", __func__,
+		       (memctrl >> 8) & 0xf);
+		return -EINVAL;
+	}
+
+	/* Number of cycles spent on memory access */
+	stat->busy_time = data->dmc[busier_dmc].count[0] / 2 * (cycles_x2 + 2);
+	stat->busy_time *= 100 / BUS_SATURATION_RATIO;
+	stat->total_time = data->dmc[busier_dmc].ccnt;
+
+	/* If the counters have overflown, retry */
+	if (data->dmc[busier_dmc].ccnt_overflow ||
+	    data->dmc[busier_dmc].count_overflow[0])
+		return -EAGAIN;
+
+	return 0;
+}
+
+static void exynos4_bus_exit(struct device *dev)
+{
+	struct busfreq_data *data = dev_get_drvdata(dev);
+
+	devfreq_unregister_opp_notifier(dev, data->devfreq);
+}
+
+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,
+	.exit		= exynos4_bus_exit,
+};
+
+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;
+	}
+
+#ifdef CONFIG_EXYNOS_ASV
+	tmp = exynos4_result_of_asv;
+#else
+	tmp = 0; /* Max voltages for the reliability of the unknown */
+#endif
+
+	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 = 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;
+	}
+
+#ifdef CONFIG_EXYNOS_ASV
+	tmp = exynos4_result_of_asv;
+#else
+	tmp = 0; /* Max voltages for the reliability of the unknown */
+#endif
+
+	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 = 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 opp *opp;
+	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;
+
+		opp = opp_find_freq_floor(data->dev, &maxfreq);
+
+		err = exynos4_bus_setvolt(data, opp, data->curr_opp);
+		if (err)
+			goto unlock;
+
+		switch (data->type) {
+		case TYPE_BUSF_EXYNOS4210:
+			err = exynos4210_set_busclk(data, opp);
+			break;
+		case TYPE_BUSF_EXYNOS4x12:
+			err = exynos4x12_set_busclk(data, opp);
+			break;
+		default:
+			err = -EINVAL;
+		}
+		if (err)
+			goto unlock;
+
+		data->curr_opp = opp;
+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 __devinit int exynos4_busfreq_probe(struct platform_device *pdev)
+{
+	struct busfreq_data *data;
+	struct opp *opp;
+	struct device *dev = &pdev->dev;
+	int err = 0;
+
+	data = kzalloc(sizeof(struct busfreq_data), GFP_KERNEL);
+	if (data == NULL) {
+		dev_err(dev, "Cannot allocate memory.\n");
+		return -ENOMEM;
+	}
+
+	data->type = pdev->id_entry->driver_data;
+	data->dmc[0].hw_base = S5P_VA_DMC0;
+	data->dmc[1].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)
+		goto err_regulator;
+
+	data->vdd_int = regulator_get(dev, "vdd_int");
+	if (IS_ERR(data->vdd_int)) {
+		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
+		err = PTR_ERR(data->vdd_int);
+		goto err_regulator;
+	}
+	if (data->type == TYPE_BUSF_EXYNOS4x12) {
+		data->vdd_mif = regulator_get(dev, "vdd_mif");
+		if (IS_ERR(data->vdd_mif)) {
+			dev_err(dev, "Cannot get the regulator \"vdd_mif\"\n");
+			err = PTR_ERR(data->vdd_mif);
+			regulator_put(data->vdd_int);
+			goto err_regulator;
+
+		}
+	}
+
+	opp = opp_find_freq_floor(dev, &exynos4_devfreq_profile.initial_freq);
+	if (IS_ERR(opp)) {
+		dev_err(dev, "Invalid initial frequency %lu kHz.\n",
+		       exynos4_devfreq_profile.initial_freq);
+		err = PTR_ERR(opp);
+		goto err_opp_add;
+	}
+	data->curr_opp = opp;
+
+	platform_set_drvdata(pdev, data);
+
+	busfreq_mon_reset(data);
+
+	data->devfreq = devfreq_add_device(dev, &exynos4_devfreq_profile,
+					   &devfreq_simple_ondemand, NULL);
+	if (IS_ERR(data->devfreq)) {
+		err = PTR_ERR(data->devfreq);
+		goto err_opp_add;
+	}
+
+	devfreq_register_opp_notifier(dev, data->devfreq);
+
+	err = register_pm_notifier(&data->pm_notifier);
+	if (err) {
+		dev_err(dev, "Failed to setup pm notifier\n");
+		goto err_devfreq_add;
+	}
+
+	return 0;
+err_devfreq_add:
+	devfreq_remove_device(data->devfreq);
+err_opp_add:
+	if (data->vdd_mif)
+		regulator_put(data->vdd_mif);
+	regulator_put(data->vdd_int);
+err_regulator:
+	kfree(data);
+	return err;
+}
+
+static __devexit int exynos4_busfreq_remove(struct platform_device *pdev)
+{
+	struct busfreq_data *data = platform_get_drvdata(pdev);
+
+	unregister_pm_notifier(&data->pm_notifier);
+	devfreq_remove_device(data->devfreq);
+	regulator_put(data->vdd_int);
+	if (data->vdd_mif)
+		regulator_put(data->vdd_mif);
+	kfree(data);
+
+	return 0;
+}
+
+static int exynos4_busfreq_resume(struct device *dev)
+{
+	struct busfreq_data *data = dev_get_drvdata(dev);
+
+	busfreq_mon_reset(data);
+	return 0;
+}
+
+static const struct dev_pm_ops exynos4_busfreq_pm = {
+	.resume	= 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	= __devexit_p(exynos4_busfreq_remove),
+	.id_table = exynos4_busfreq_id,
+	.driver = {
+		.name	= "exynos4-busfreq",
+		.owner	= THIS_MODULE,
+		.pm	= &exynos4_busfreq_pm,
+	},
+};
+
+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/governor.h b/drivers/devfreq/governor.h
new file mode 100644
index 00000000..ea7f13c5
--- /dev/null
+++ b/drivers/devfreq/governor.h
@@ -0,0 +1,24 @@
+/*
+ * 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)
+
+/* Caution: devfreq->lock must be locked before calling update_devfreq */
+extern int update_devfreq(struct devfreq *devfreq);
+
+#endif /* _GOVERNOR_H */
diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
new file mode 100644
index 00000000..af75ddd4
--- /dev/null
+++ b/drivers/devfreq/governor_performance.c
@@ -0,0 +1,39 @@
+/*
+ *  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 "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 performance_init(struct devfreq *devfreq)
+{
+	return update_devfreq(devfreq);
+}
+
+const struct devfreq_governor devfreq_performance = {
+	.name = "performance",
+	.init = performance_init,
+	.get_target_freq = devfreq_performance_func,
+	.no_central_polling = true,
+};
diff --git a/drivers/devfreq/governor_powersave.c b/drivers/devfreq/governor_powersave.c
new file mode 100644
index 00000000..fec0cdbd
--- /dev/null
+++ b/drivers/devfreq/governor_powersave.c
@@ -0,0 +1,36 @@
+/*
+ *  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 "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 powersave_init(struct devfreq *devfreq)
+{
+	return update_devfreq(devfreq);
+}
+
+const struct devfreq_governor devfreq_powersave = {
+	.name = "powersave",
+	.init = powersave_init,
+	.get_target_freq = devfreq_powersave_func,
+	.no_central_polling = true,
+};
diff --git a/drivers/devfreq/governor_simpleondemand.c b/drivers/devfreq/governor_simpleondemand.c
new file mode 100644
index 00000000..a2e3eae7
--- /dev/null
+++ b/drivers/devfreq/governor_simpleondemand.c
@@ -0,0 +1,94 @@
+/*
+ *  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/devfreq.h>
+#include <linux/math64.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;
+}
+
+const struct devfreq_governor devfreq_simple_ondemand = {
+	.name = "simple_ondemand",
+	.get_target_freq = devfreq_simple_ondemand_func,
+};
diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
new file mode 100644
index 00000000..0681246f
--- /dev/null
+++ b/drivers/devfreq/governor_userspace.c
@@ -0,0 +1,125 @@
+/*
+ *  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 "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;
+}
+
+const struct devfreq_governor devfreq_userspace = {
+	.name = "userspace",
+	.get_target_freq = devfreq_userspace_func,
+	.init = userspace_init,
+	.exit = userspace_exit,
+	.no_central_polling = true,
+};