Merge tag 'pull_req_20150129' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq into pm-devfreq

Pull devfreq changes for v3.20 from MyungJoo Ham.

* tag 'pull_req_20150129' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq:
  PM / devfreq: event: Add documentation for exynos-ppmu devfreq-event driver
  devfreq: Fix build break of devfreq-event class
  PM / devfreq: event: Add devfreq_event class
  PM / devfreq: tegra: add devfreq driver for Tegra Activity Monitor

8 files changed, 1723 insertions, 0 deletions

diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index faf4e70c42e0..51dccb3620ea 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -87,4 +87,16 @@ config ARM_EXYNOS5_BUS_DEVFREQ
 	  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
index 16138c9e0d58..5134f9ee983d 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -1,4 +1,5 @@
 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-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
@@ -7,3 +8,7 @@ obj-$(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 000000000000..f304a0289eda
--- /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/event/Kconfig b/drivers/devfreq/event/Kconfig
new file mode 100644
index 000000000000..a11720affc31
--- /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 000000000000..be146ead79cf
--- /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 000000000000..135be0aada9d
--- /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 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)) {
+			ret = PTR_ERR(edev);
+			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 000000000000..4e831d48c138
--- /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/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
new file mode 100644
index 000000000000..34790961af5a
--- /dev/null
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -0,0 +1,718 @@
+/*
+ * 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 in %
+ */
+struct tegra_devfreq_device_config {
+	u32		offset;
+	u32		irq_mask;
+
+	unsigned int	boost_up_coeff;
+	unsigned int	boost_down_coeff;
+	unsigned int	boost_up_threshold;
+	unsigned int	boost_down_threshold;
+	u32		avg_dependency_threshold;
+};
+
+enum tegra_actmon_device {
+	MCALL = 0,
+	MCCPU,
+};
+
+static struct tegra_devfreq_device_config actmon_device_configs[] = {
+	{
+		/* MCALL */
+		.offset = 0x1c0,
+		.irq_mask = 1 << 26,
+		.boost_up_coeff = 200,
+		.boost_down_coeff = 50,
+		.boost_up_threshold = 60,
+		.boost_down_threshold = 40,
+	},
+	{
+		/* MCCPU */
+		.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;
+	u32		avg_band_freq;
+	u32		avg_count;
+
+	unsigned long	target_freq;
+	unsigned long	boost_freq;
+};
+
+struct tegra_devfreq {
+	struct devfreq		*devfreq;
+
+	struct platform_device	*pdev;
+	struct reset_control	*reset;
+	struct clk		*clock;
+	void __iomem		*regs;
+
+	spinlock_t		lock;
+
+	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 unsigned long do_percent(unsigned long val, unsigned int pct)
+{
+	return val * pct / 100;
+}
+
+static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq_device *dev)
+{
+	u32 avg = dev->avg_count;
+	u32 band = dev->avg_band_freq * ACTMON_SAMPLING_PERIOD;
+
+	writel(avg + band, dev->regs + ACTMON_DEV_AVG_UPPER_WMARK);
+	avg = max(avg, band);
+	writel(avg - band, dev->regs + 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;
+
+	writel(do_percent(val, dev->config->boost_up_threshold),
+	       dev->regs + ACTMON_DEV_UPPER_WMARK);
+
+	writel(do_percent(val, dev->config->boost_down_threshold),
+	       dev->regs + ACTMON_DEV_LOWER_WMARK);
+}
+
+static void actmon_write_barrier(struct tegra_devfreq *tegra)
+{
+	/* ensure the update has reached the ACTMON */
+	wmb();
+	readl(tegra->regs + ACTMON_GLB_STATUS);
+}
+
+static irqreturn_t actmon_isr(int irq, void *data)
+{
+	struct tegra_devfreq *tegra = data;
+	struct tegra_devfreq_device *dev = NULL;
+	unsigned long flags;
+	u32 val;
+	unsigned int i;
+
+	val = readl(tegra->regs + ACTMON_GLB_STATUS);
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		if (val & tegra->devices[i].config->irq_mask) {
+			dev = tegra->devices + i;
+			break;
+		}
+	}
+
+	if (!dev)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&tegra->lock, flags);
+
+	dev->avg_count = readl(dev->regs + ACTMON_DEV_AVG_COUNT);
+	tegra_devfreq_update_avg_wmark(dev);
+
+	val = readl(dev->regs + ACTMON_DEV_INTR_STATUS);
+	if (val & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) {
+		val = readl(dev->regs + ACTMON_DEV_CTRL) |
+			ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN |
+			ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+
+		/*
+		 * 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;
+		if (dev->boost_freq >= tegra->max_freq) {
+			dev->boost_freq = tegra->max_freq;
+			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+		}
+		writel(val, dev->regs + ACTMON_DEV_CTRL);
+	} else if (val & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {
+		val = readl(dev->regs + ACTMON_DEV_CTRL) |
+			ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN |
+			ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+
+		/*
+		 * 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);
+		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) {
+			dev->boost_freq = 0;
+			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		}
+		writel(val, dev->regs + ACTMON_DEV_CTRL);
+	}
+
+	if (dev->config->avg_dependency_threshold) {
+		val = readl(dev->regs + ACTMON_DEV_CTRL);
+		if (dev->avg_count >= dev->config->avg_dependency_threshold)
+			val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		else if (dev->boost_freq == 0)
+			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		writel(val, dev->regs + ACTMON_DEV_CTRL);
+	}
+
+	writel(ACTMON_INTR_STATUS_CLEAR, dev->regs + ACTMON_DEV_INTR_STATUS);
+
+	actmon_write_barrier(tegra);
+
+	spin_unlock_irqrestore(&tegra->lock, flags);
+
+	return IRQ_WAKE_THREAD;
+}
+
+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(&tegra->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(&tegra->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 = container_of(nb, struct tegra_devfreq,
+						   rate_change_nb);
+	unsigned int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tegra->lock, flags);
+
+	switch (action) {
+	case POST_RATE_CHANGE:
+		tegra->cur_freq = data->new_rate / KHZ;
+
+		for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)
+			tegra_devfreq_update_wmark(tegra, tegra->devices + i);
+
+		actmon_write_barrier(tegra);
+		break;
+	case PRE_RATE_CHANGE:
+		/* fall through */
+	case ABORT_RATE_CHANGE:
+		break;
+	};
+
+	spin_unlock_irqrestore(&tegra->lock, flags);
+
+	return NOTIFY_OK;
+}
+
+static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
+					  struct tegra_devfreq_device *dev)
+{
+	u32 val;
+
+	dev->avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
+	dev->target_freq = tegra->cur_freq;
+
+	dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
+	writel(dev->avg_count, dev->regs + ACTMON_DEV_INIT_AVG);
+
+	tegra_devfreq_update_avg_wmark(dev);
+	tegra_devfreq_update_wmark(tegra, dev);
+
+	writel(ACTMON_COUNT_WEIGHT, dev->regs + ACTMON_DEV_COUNT_WEIGHT);
+	writel(ACTMON_INTR_STATUS_CLEAR, dev->regs + ACTMON_DEV_INTR_STATUS);
+
+	val = 0;
+	val |= ACTMON_DEV_CTRL_ENB_PERIODIC |
+	       ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN |
+	       ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
+	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_CONSECUTIVE_BELOW_WMARK_EN |
+	       ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+
+	writel(val, dev->regs + ACTMON_DEV_CTRL);
+
+	actmon_write_barrier(tegra);
+
+	val = readl(dev->regs + ACTMON_DEV_CTRL);
+	val |= ACTMON_DEV_CTRL_ENB;
+	writel(val, dev->regs + ACTMON_DEV_CTRL);
+
+	actmon_write_barrier(tegra);
+}
+
+static int tegra_devfreq_suspend(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *actmon_dev;
+	unsigned int i;
+	u32 val;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	tegra = platform_get_drvdata(pdev);
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		actmon_dev = &tegra->devices[i];
+
+		val = readl(actmon_dev->regs + ACTMON_DEV_CTRL);
+		val &= ~ACTMON_DEV_CTRL_ENB;
+		writel(val, actmon_dev->regs + ACTMON_DEV_CTRL);
+
+		writel(ACTMON_INTR_STATUS_CLEAR,
+		       actmon_dev->regs + ACTMON_DEV_INTR_STATUS);
+
+		actmon_write_barrier(tegra);
+	}
+
+	return 0;
+}
+
+static int tegra_devfreq_resume(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *actmon_dev;
+	unsigned int i;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	tegra = platform_get_drvdata(pdev);
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		actmon_dev = &tegra->devices[i];
+
+		tegra_actmon_configure_device(tegra, actmon_dev);
+	}
+
+	return 0;
+}
+
+static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
+				u32 flags)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra;
+	struct dev_pm_opp *opp;
+	unsigned long rate = *freq * KHZ;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	tegra = platform_get_drvdata(pdev);
+
+	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();
+
+	/* TODO: Once we have per-user clk constraints, set a floor */
+	clk_set_rate(tegra->emc_clock, rate);
+
+	/* TODO: Set voltage as well */
+
+	return 0;
+}
+
+static int tegra_devfreq_get_dev_status(struct device *dev,
+					struct devfreq_dev_status *stat)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *actmon_dev;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	tegra = platform_get_drvdata(pdev);
+
+	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 = 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;
+
+	return 0;
+}
+
+static int tegra_devfreq_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_devfreq_event_handler(struct devfreq *devfreq,
+				       unsigned int event, void *data)
+{
+	return 0;
+}
+
+static struct devfreq_governor tegra_devfreq_governor = {
+	.name = "tegra",
+	.get_target_freq = tegra_devfreq_get_target,
+	.event_handler = tegra_devfreq_event_handler,
+};
+
+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_devfreq_probe(struct platform_device *pdev)
+{
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *dev;
+	struct resource *res;
+	unsigned long max_freq;
+	unsigned int i;
+	int irq;
+	int err;
+
+	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
+	if (!tegra)
+		return -ENOMEM;
+
+	spin_lock_init(&tegra->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get regs resource\n");
+		return -ENODEV;
+	}
+
+	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tegra->regs)) {
+		dev_err(&pdev->dev, "Failed to get IO memory\n");
+		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);
+	}
+
+	err = of_init_opp_table(&pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to init operating point table\n");
+		return err;
+	}
+
+	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) {
+		reset_control_deassert(tegra->reset);
+		return err;
+	}
+
+	reset_control_deassert(tegra->reset);
+
+	max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX);
+	tegra->max_freq = max_freq / KHZ;
+
+	clk_set_rate(tegra->emc_clock, max_freq);
+
+	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
+
+	writel(ACTMON_SAMPLING_PERIOD - 1,
+	       tegra->regs + 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;
+
+		tegra_actmon_configure_device(tegra, tegra->devices + i);
+	}
+
+	err = devfreq_add_governor(&tegra_devfreq_governor);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to add governor\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",
+						 NULL);
+
+	irq = platform_get_irq(pdev, 0);
+	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;
+	}
+
+	platform_set_drvdata(pdev, tegra);
+
+	return 0;
+}
+
+static int tegra_devfreq_remove(struct platform_device *pdev)
+{
+	struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
+
+	clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
+
+	clk_disable_unprepare(tegra->clock);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(tegra_devfreq_pm_ops,
+			 tegra_devfreq_suspend,
+			 tegra_devfreq_resume);
+
+static struct of_device_id tegra_devfreq_of_match[] = {
+	{ .compatible = "nvidia,tegra124-actmon" },
+	{ },
+};
+
+static struct platform_driver tegra_devfreq_driver = {
+	.probe	= tegra_devfreq_probe,
+	.remove	= tegra_devfreq_remove,
+	.driver = {
+		.name		= "tegra-devfreq",
+		.owner		= THIS_MODULE,
+		.of_match_table = tegra_devfreq_of_match,
+		.pm		= &tegra_devfreq_pm_ops,
+	},
+};
+module_platform_driver(tegra_devfreq_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Tegra devfreq driver");
+MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>");
+MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);