Merge branch 'pm-devfreq'

* pm-devfreq:
  MAINTAINERS: update mailing list for devfreq(DVFS).
  PM / devfreq: fix typo "CPU_EXYNOS4.12" twice
  PM / devfreq: fix missing unlock on error in exynos4_busfreq_pm_notifier_event()
  PM / devfreq: add comments and Documentation
  PM / devfreq: account suspend/resume for stats
  PM / devfreq: Add Exynos5-bus devfreq driver for Exynos5250
  PM / devfreq: Move exynos4 devfreq driver into a new sub-directory

Documentation/ABI/testing/sysfs-class-devfreq

@@ -78,3 +78,23 @@ Contact:	Nishanth Menon <nm@ti.com>
 Description:
 		The /sys/class/devfreq/.../available_governors shows
 		currently available governors in the system.
+
+What:		/sys/class/devfreq/.../min_freq
+Date:		January 2013
+Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+		The /sys/class/devfreq/.../min_freq shows and stores
+		the minimum frequency requested by users. It is 0 if
+		the user does not care. min_freq overrides the
+		frequency requested by governors.
+
+What:		/sys/class/devfreq/.../max_freq
+Date:		January 2013
+Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
+Description:
+		The /sys/class/devfreq/.../max_freq shows and stores
+		the maximum frequency requested by users. It is 0 if
+		the user does not care. max_freq overrides the
+		frequency requested by governors and min_freq.
+		The max_freq overrides min_freq because max_freq may be
+		used to throttle devices to avoid overheating.

MAINTAINERS

@@ -2519,7 +2519,7 @@ F:	drivers/usb/dwc3/
 DEVICE FREQUENCY (DEVFREQ)
 M:	MyungJoo Ham <myungjoo.ham@samsung.com>
 M:	Kyungmin Park <kyungmin.park@samsung.com>
-L:	linux-kernel@vger.kernel.org
+L:	linux-pm@vger.kernel.org
 S:	Maintained
 F:	drivers/devfreq/
 

drivers/devfreq/Kconfig

@@ -67,7 +67,7 @@ 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
+	depends on CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412
 	select ARCH_HAS_OPP
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
 	help
@@ -78,4 +78,14 @@ config ARM_EXYNOS4_BUS_DEVFREQ
 	  To operate with optimal voltages, ASV support is required
 	  (CONFIG_EXYNOS_ASV).
 
+config ARM_EXYNOS5_BUS_DEVFREQ
+	bool "ARM Exynos5250 Bus DEVFREQ Driver"
+	depends on SOC_EXYNOS5250
+	select ARCH_HAS_OPP
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	help
+	  This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
+	  It reads PPMU counters of memory controllers and adjusts the
+	  operating frequencies and voltages with OPP support.
+
 endif # PM_DEVFREQ

drivers/devfreq/Makefile

@@ -5,4 +5,5 @@ obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
 obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 
 # DEVFREQ Drivers
-obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos4_bus.o
+obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/

drivers/devfreq/devfreq.c

@@ -271,6 +271,7 @@ void devfreq_monitor_suspend(struct devfreq *devfreq)
 		return;
 	}
 
+	devfreq_update_status(devfreq, devfreq->previous_freq);
 	devfreq->stop_polling = true;
 	mutex_unlock(&devfreq->lock);
 	cancel_delayed_work_sync(&devfreq->work);
@@ -287,6 +288,8 @@ EXPORT_SYMBOL(devfreq_monitor_suspend);
  */
 void devfreq_monitor_resume(struct devfreq *devfreq)
 {
+	unsigned long freq;
+
 	mutex_lock(&devfreq->lock);
 	if (!devfreq->stop_polling)
 		goto out;
@@ -295,8 +298,14 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
 			devfreq->profile->polling_ms)
 		queue_delayed_work(devfreq_wq, &devfreq->work,
 			msecs_to_jiffies(devfreq->profile->polling_ms));
+
+	devfreq->last_stat_updated = jiffies;
 	devfreq->stop_polling = false;
 
+	if (devfreq->profile->get_cur_freq &&
+		!devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
+		devfreq->previous_freq = freq;
+
 out:
 	mutex_unlock(&devfreq->lock);
 }
@@ -518,6 +527,8 @@ EXPORT_SYMBOL(devfreq_add_device);
 /**
  * devfreq_remove_device() - Remove devfreq feature from a device.
  * @devfreq:	the devfreq instance to be removed
+ *
+ * The opposite of devfreq_add_device().
  */
 int devfreq_remove_device(struct devfreq *devfreq)
 {
@@ -533,6 +544,10 @@ EXPORT_SYMBOL(devfreq_remove_device);
 /**
  * devfreq_suspend_device() - Suspend devfreq of a device.
  * @devfreq: the devfreq instance to be suspended
+ *
+ * This function is intended to be called by the pm callbacks
+ * (e.g., runtime_suspend, suspend) of the device driver that
+ * holds the devfreq.
  */
 int devfreq_suspend_device(struct devfreq *devfreq)
 {
@@ -550,6 +565,10 @@ EXPORT_SYMBOL(devfreq_suspend_device);
 /**
  * devfreq_resume_device() - Resume devfreq of a device.
  * @devfreq: the devfreq instance to be resumed
+ *
+ * This function is intended to be called by the pm callbacks
+ * (e.g., runtime_resume, resume) of the device driver that
+ * holds the devfreq.
  */
 int devfreq_resume_device(struct devfreq *devfreq)
 {
@@ -905,11 +924,11 @@ static ssize_t show_trans_table(struct device *dev, struct device_attribute *att
 {
 	struct devfreq *devfreq = to_devfreq(dev);
 	ssize_t len;
-	int i, j, err;
+	int i, j;
 	unsigned int max_state = devfreq->profile->max_state;
 
-	err = devfreq_update_status(devfreq, devfreq->previous_freq);
+	if (!devfreq->stop_polling &&
-	if (err)
+			devfreq_update_status(devfreq, devfreq->previous_freq))
 		return 0;
 
 	len = sprintf(buf, "   From  :   To\n");

drivers/devfreq/exynos/Makefile

@@ -0,0 +1,3 @@
+# Exynos DEVFREQ Drivers
+obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos4_bus.o
+obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos_ppmu.o exynos5_bus.o

drivers/devfreq/exynos/exynos4_bus.c

@@ -974,6 +974,7 @@ static int exynos4_busfreq_pm_notifier_event(struct notifier_block *this,
 			rcu_read_unlock();
 			dev_err(data->dev, "%s: unable to find a min freq\n",
 				__func__);
+			mutex_unlock(&data->lock);
 			return PTR_ERR(opp);
 		}
 		new_oppinfo.rate = opp_get_freq(opp);

drivers/devfreq/exynos/exynos5_bus.c

@@ -0,0 +1,503 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS5 INT clock frequency scaling support using DEVFREQ framework
+ * Based on work done by Jonghwan Choi <jhbird.choi@samsung.com>
+ * Support for only EXYNOS5250 is present.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/devfreq.h>
+#include <linux/io.h>
+#include <linux/opp.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <linux/opp.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/pm_qos.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+
+#include "exynos_ppmu.h"
+
+#define MAX_SAFEVOLT			1100000 /* 1.10V */
+/* Assume that the bus is saturated if the utilization is 25% */
+#define INT_BUS_SATURATION_RATIO	25
+
+enum int_level_idx {
+	LV_0,
+	LV_1,
+	LV_2,
+	LV_3,
+	LV_4,
+	_LV_END
+};
+
+enum exynos_ppmu_list {
+	PPMU_RIGHT,
+	PPMU_END,
+};
+
+struct busfreq_data_int {
+	struct device *dev;
+	struct devfreq *devfreq;
+	struct regulator *vdd_int;
+	struct exynos_ppmu ppmu[PPMU_END];
+	unsigned long curr_freq;
+	bool disabled;
+
+	struct notifier_block pm_notifier;
+	struct mutex lock;
+	struct pm_qos_request int_req;
+	struct clk *int_clk;
+};
+
+struct int_bus_opp_table {
+	unsigned int idx;
+	unsigned long clk;
+	unsigned long volt;
+};
+
+static struct int_bus_opp_table exynos5_int_opp_table[] = {
+	{LV_0, 266000, 1025000},
+	{LV_1, 200000, 1025000},
+	{LV_2, 160000, 1025000},
+	{LV_3, 133000, 1025000},
+	{LV_4, 100000, 1025000},
+	{0, 0, 0},
+};
+
+static void busfreq_mon_reset(struct busfreq_data_int *data)
+{
+	unsigned int i;
+
+	for (i = PPMU_RIGHT; i < PPMU_END; i++) {
+		void __iomem *ppmu_base = data->ppmu[i].hw_base;
+
+		/* Reset the performance and cycle counters */
+		exynos_ppmu_reset(ppmu_base);
+
+		/* Setup count registers to monitor read/write transactions */
+		data->ppmu[i].event[PPMU_PMNCNT3] = RDWR_DATA_COUNT;
+		exynos_ppmu_setevent(ppmu_base, PPMU_PMNCNT3,
+					data->ppmu[i].event[PPMU_PMNCNT3]);
+
+		exynos_ppmu_start(ppmu_base);
+	}
+}
+
+static void exynos5_read_ppmu(struct busfreq_data_int *data)
+{
+	int i, j;
+
+	for (i = PPMU_RIGHT; i < PPMU_END; i++) {
+		void __iomem *ppmu_base = data->ppmu[i].hw_base;
+
+		exynos_ppmu_stop(ppmu_base);
+
+		/* Update local data from PPMU */
+		data->ppmu[i].ccnt = __raw_readl(ppmu_base + PPMU_CCNT);
+
+		for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
+			if (data->ppmu[i].event[j] == 0)
+				data->ppmu[i].count[j] = 0;
+			else
+				data->ppmu[i].count[j] =
+					exynos_ppmu_read(ppmu_base, j);
+		}
+	}
+
+	busfreq_mon_reset(data);
+}
+
+static int exynos5_int_setvolt(struct busfreq_data_int *data,
+				unsigned long volt)
+{
+	return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT);
+}
+
+static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq,
+			      u32 flags)
+{
+	int err = 0;
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+	struct opp *opp;
+	unsigned long old_freq, freq;
+	unsigned long volt;
+
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, _freq, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "%s: Invalid OPP.\n", __func__);
+		return PTR_ERR(opp);
+	}
+
+	freq = opp_get_freq(opp);
+	volt = opp_get_voltage(opp);
+	rcu_read_unlock();
+
+	old_freq = data->curr_freq;
+
+	if (old_freq == freq)
+		return 0;
+
+	dev_dbg(dev, "targetting %lukHz %luuV\n", freq, volt);
+
+	mutex_lock(&data->lock);
+
+	if (data->disabled)
+		goto out;
+
+	if (freq > exynos5_int_opp_table[0].clk)
+		pm_qos_update_request(&data->int_req, freq * 16 / 1000);
+	else
+		pm_qos_update_request(&data->int_req, -1);
+
+	if (old_freq < freq)
+		err = exynos5_int_setvolt(data, volt);
+	if (err)
+		goto out;
+
+	err = clk_set_rate(data->int_clk, freq * 1000);
+
+	if (err)
+		goto out;
+
+	if (old_freq > freq)
+		err = exynos5_int_setvolt(data, volt);
+	if (err)
+		goto out;
+
+	data->curr_freq = freq;
+out:
+	mutex_unlock(&data->lock);
+	return err;
+}
+
+static int exynos5_get_busier_dmc(struct busfreq_data_int *data)
+{
+	int i, j;
+	int busy = 0;
+	unsigned int temp = 0;
+
+	for (i = PPMU_RIGHT; i < PPMU_END; i++) {
+		for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
+			if (data->ppmu[i].count[j] > temp) {
+				temp = data->ppmu[i].count[j];
+				busy = i;
+			}
+		}
+	}
+
+	return busy;
+}
+
+static int exynos5_int_get_dev_status(struct device *dev,
+				      struct devfreq_dev_status *stat)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+	int busier_dmc;
+
+	exynos5_read_ppmu(data);
+	busier_dmc = exynos5_get_busier_dmc(data);
+
+	stat->current_frequency = data->curr_freq;
+
+	/* Number of cycles spent on memory access */
+	stat->busy_time = data->ppmu[busier_dmc].count[PPMU_PMNCNT3];
+	stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO;
+	stat->total_time = data->ppmu[busier_dmc].ccnt;
+
+	return 0;
+}
+static void exynos5_int_exit(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	devfreq_unregister_opp_notifier(dev, data->devfreq);
+}
+
+static struct devfreq_dev_profile exynos5_devfreq_int_profile = {
+	.initial_freq		= 160000,
+	.polling_ms		= 100,
+	.target			= exynos5_busfreq_int_target,
+	.get_dev_status		= exynos5_int_get_dev_status,
+	.exit			= exynos5_int_exit,
+};
+
+static int exynos5250_init_int_tables(struct busfreq_data_int *data)
+{
+	int i, err = 0;
+
+	for (i = LV_0; i < _LV_END; i++) {
+		err = opp_add(data->dev, exynos5_int_opp_table[i].clk,
+				exynos5_int_opp_table[i].volt);
+		if (err) {
+			dev_err(data->dev, "Cannot add opp entries.\n");
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this,
+		unsigned long event, void *ptr)
+{
+	struct busfreq_data_int *data = container_of(this,
+					struct busfreq_data_int, pm_notifier);
+	struct opp *opp;
+	unsigned long maxfreq = ULONG_MAX;
+	unsigned long freq;
+	unsigned long volt;
+	int err = 0;
+
+	switch (event) {
+	case PM_SUSPEND_PREPARE:
+		/* Set Fastest and Deactivate DVFS */
+		mutex_lock(&data->lock);
+
+		data->disabled = true;
+
+		rcu_read_lock();
+		opp = opp_find_freq_floor(data->dev, &maxfreq);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			err = PTR_ERR(opp);
+			goto unlock;
+		}
+		freq = opp_get_freq(opp);
+		volt = opp_get_voltage(opp);
+		rcu_read_unlock();
+
+		err = exynos5_int_setvolt(data, volt);
+		if (err)
+			goto unlock;
+
+		err = clk_set_rate(data->int_clk, freq * 1000);
+
+		if (err)
+			goto unlock;
+
+		data->curr_freq = freq;
+unlock:
+		mutex_unlock(&data->lock);
+		if (err)
+			return NOTIFY_BAD;
+		return NOTIFY_OK;
+	case PM_POST_RESTORE:
+	case PM_POST_SUSPEND:
+		/* Reactivate */
+		mutex_lock(&data->lock);
+		data->disabled = false;
+		mutex_unlock(&data->lock);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int exynos5_busfreq_int_probe(struct platform_device *pdev)
+{
+	struct busfreq_data_int *data;
+	struct opp *opp;
+	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	unsigned long initial_freq;
+	unsigned long initial_volt;
+	int err = 0;
+	int i;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int),
+				GFP_KERNEL);
+	if (data == NULL) {
+		dev_err(dev, "Cannot allocate memory.\n");
+		return -ENOMEM;
+	}
+
+	np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu");
+	if (np == NULL) {
+		pr_err("Unable to find PPMU node\n");
+		return -ENOENT;
+	}
+
+	for (i = PPMU_RIGHT; i < PPMU_END; i++) {
+		/* map PPMU memory region */
+		data->ppmu[i].hw_base = of_iomap(np, i);
+		if (data->ppmu[i].hw_base == NULL) {
+			dev_err(&pdev->dev, "failed to map memory region\n");
+			return -ENOMEM;
+		}
+	}
+	data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event;
+	data->dev = dev;
+	mutex_init(&data->lock);
+
+	err = exynos5250_init_int_tables(data);
+	if (err)
+		goto err_regulator;
+
+	data->vdd_int = regulator_get(dev, "vdd_int");
+	if (IS_ERR(data->vdd_int)) {
+		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
+		err = PTR_ERR(data->vdd_int);
+		goto err_regulator;
+	}
+
+	data->int_clk = clk_get(dev, "int_clk");
+	if (IS_ERR(data->int_clk)) {
+		dev_err(dev, "Cannot get clock \"int_clk\"\n");
+		err = PTR_ERR(data->int_clk);
+		goto err_clock;
+	}
+
+	rcu_read_lock();
+	opp = opp_find_freq_floor(dev,
+			&exynos5_devfreq_int_profile.initial_freq);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "Invalid initial frequency %lu kHz.\n",
+		       exynos5_devfreq_int_profile.initial_freq);
+		err = PTR_ERR(opp);
+		goto err_opp_add;
+	}
+	initial_freq = opp_get_freq(opp);
+	initial_volt = opp_get_voltage(opp);
+	rcu_read_unlock();
+	data->curr_freq = initial_freq;
+
+	err = clk_set_rate(data->int_clk, initial_freq * 1000);
+	if (err) {
+		dev_err(dev, "Failed to set initial frequency\n");
+		goto err_opp_add;
+	}
+
+	err = exynos5_int_setvolt(data, initial_volt);
+	if (err)
+		goto err_opp_add;
+
+	platform_set_drvdata(pdev, data);
+
+	busfreq_mon_reset(data);
+
+	data->devfreq = devfreq_add_device(dev, &exynos5_devfreq_int_profile,
+					   "simple_ondemand", NULL);
+
+	if (IS_ERR(data->devfreq)) {
+		err = PTR_ERR(data->devfreq);
+		goto err_devfreq_add;
+	}
+
+	devfreq_register_opp_notifier(dev, data->devfreq);
+
+	err = register_pm_notifier(&data->pm_notifier);
+	if (err) {
+		dev_err(dev, "Failed to setup pm notifier\n");
+		goto err_devfreq_add;
+	}
+
+	/* TODO: Add a new QOS class for int/mif bus */
+	pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1);
+
+	return 0;
+
+err_devfreq_add:
+	devfreq_remove_device(data->devfreq);
+	platform_set_drvdata(pdev, NULL);
+err_opp_add:
+	clk_put(data->int_clk);
+err_clock:
+	regulator_put(data->vdd_int);
+err_regulator:
+	return err;
+}
+
+static int exynos5_busfreq_int_remove(struct platform_device *pdev)
+{
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	pm_qos_remove_request(&data->int_req);
+	unregister_pm_notifier(&data->pm_notifier);
+	devfreq_remove_device(data->devfreq);
+	regulator_put(data->vdd_int);
+	clk_put(data->int_clk);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static int exynos5_busfreq_int_resume(struct device *dev)
+{
+	struct platform_device *pdev = container_of(dev, struct platform_device,
+						    dev);
+	struct busfreq_data_int *data = platform_get_drvdata(pdev);
+
+	busfreq_mon_reset(data);
+	return 0;
+}
+
+static const struct dev_pm_ops exynos5_busfreq_int_pm = {
+	.resume	= exynos5_busfreq_int_resume,
+};
+
+/* platform device pointer for exynos5 devfreq device. */
+static struct platform_device *exynos5_devfreq_pdev;
+
+static struct platform_driver exynos5_busfreq_int_driver = {
+	.probe		= exynos5_busfreq_int_probe,
+	.remove		= exynos5_busfreq_int_remove,
+	.driver		= {
+		.name		= "exynos5-bus-int",
+		.owner		= THIS_MODULE,
+		.pm		= &exynos5_busfreq_int_pm,
+	},
+};
+
+static int __init exynos5_busfreq_int_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&exynos5_busfreq_int_driver);
+	if (ret < 0)
+		goto out;
+
+	exynos5_devfreq_pdev =
+		platform_device_register_simple("exynos5-bus-int", -1, NULL, 0);
+	if (IS_ERR_OR_NULL(exynos5_devfreq_pdev)) {
+		ret = PTR_ERR(exynos5_devfreq_pdev);
+		goto out1;
+	}
+
+	return 0;
+out1:
+	platform_driver_unregister(&exynos5_busfreq_int_driver);
+out:
+	return ret;
+}
+late_initcall(exynos5_busfreq_int_init);
+
+static void __exit exynos5_busfreq_int_exit(void)
+{
+	platform_device_unregister(exynos5_devfreq_pdev);
+	platform_driver_unregister(&exynos5_busfreq_int_driver);
+}
+module_exit(exynos5_busfreq_int_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework");

drivers/devfreq/exynos/exynos_ppmu.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS - PPMU support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/io.h>
+
+#include "exynos_ppmu.h"
+
+void exynos_ppmu_reset(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_CYCLE_RESET | PPMU_COUNTER_RESET, ppmu_base);
+	__raw_writel(PPMU_ENABLE_CYCLE  |
+		     PPMU_ENABLE_COUNT0 |
+		     PPMU_ENABLE_COUNT1 |
+		     PPMU_ENABLE_COUNT2 |
+		     PPMU_ENABLE_COUNT3,
+		     ppmu_base + PPMU_CNTENS);
+}
+
+void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
+			unsigned int evt)
+{
+	__raw_writel(evt, ppmu_base + PPMU_BEVTSEL(ch));
+}
+
+void exynos_ppmu_start(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_ENABLE, ppmu_base);
+}
+
+void exynos_ppmu_stop(void __iomem *ppmu_base)
+{
+	__raw_writel(PPMU_DISABLE, ppmu_base);
+}
+
+unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch)
+{
+	unsigned int total;
+
+	if (ch == PPMU_PMNCNT3)
+		total = ((__raw_readl(ppmu_base + PMCNT_OFFSET(ch)) << 8) |
+			  __raw_readl(ppmu_base + PMCNT_OFFSET(ch + 1)));
+	else
+		total = __raw_readl(ppmu_base + PMCNT_OFFSET(ch));
+
+	return total;
+}

drivers/devfreq/exynos/exynos_ppmu.h

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * EXYNOS PPMU header
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#ifndef __DEVFREQ_EXYNOS_PPMU_H
+#define __DEVFREQ_EXYNOS_PPMU_H __FILE__
+
+#include <linux/ktime.h>
+
+/* For PPMU Control */
+#define PPMU_ENABLE             BIT(0)
+#define PPMU_DISABLE            0x0
+#define PPMU_CYCLE_RESET        BIT(1)
+#define PPMU_COUNTER_RESET      BIT(2)
+
+#define PPMU_ENABLE_COUNT0      BIT(0)
+#define PPMU_ENABLE_COUNT1      BIT(1)
+#define PPMU_ENABLE_COUNT2      BIT(2)
+#define PPMU_ENABLE_COUNT3      BIT(3)
+#define PPMU_ENABLE_CYCLE       BIT(31)
+
+#define PPMU_CNTENS		0x10
+#define PPMU_FLAG		0x50
+#define PPMU_CCNT_OVERFLOW	BIT(31)
+#define PPMU_CCNT		0x100
+
+#define PPMU_PMCNT0		0x110
+#define PPMU_PMCNT_OFFSET	0x10
+#define PMCNT_OFFSET(x)		(PPMU_PMCNT0 + (PPMU_PMCNT_OFFSET * x))
+
+#define PPMU_BEVT0SEL		0x1000
+#define PPMU_BEVTSEL_OFFSET	0x100
+#define PPMU_BEVTSEL(x)		(PPMU_BEVT0SEL + (ch * PPMU_BEVTSEL_OFFSET))
+
+/* For Event Selection */
+#define RD_DATA_COUNT		0x5
+#define WR_DATA_COUNT		0x6
+#define RDWR_DATA_COUNT		0x7
+
+enum ppmu_counter {
+	PPMU_PMNCNT0,
+	PPMU_PMCCNT1,
+	PPMU_PMNCNT2,
+	PPMU_PMNCNT3,
+	PPMU_PMNCNT_MAX,
+};
+
+struct bus_opp_table {
+	unsigned int idx;
+	unsigned long clk;
+	unsigned long volt;
+};
+
+struct exynos_ppmu {
+	void __iomem *hw_base;
+	unsigned int ccnt;
+	unsigned int event[PPMU_PMNCNT_MAX];
+	unsigned int count[PPMU_PMNCNT_MAX];
+	unsigned long long ns;
+	ktime_t reset_time;
+	bool ccnt_overflow;
+	bool count_overflow[PPMU_PMNCNT_MAX];
+};
+
+void exynos_ppmu_reset(void __iomem *ppmu_base);
+void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
+			unsigned int evt);
+void exynos_ppmu_start(void __iomem *ppmu_base);
+void exynos_ppmu_stop(void __iomem *ppmu_base);
+unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch);
+#endif /* __DEVFREQ_EXYNOS_PPMU_H */

include/linux/devfreq.h

@@ -181,6 +181,8 @@ extern struct devfreq *devfreq_add_device(struct device *dev,
 				  const char *governor_name,
 				  void *data);
 extern int devfreq_remove_device(struct devfreq *devfreq);
+
+/* Supposed to be called by PM_SLEEP/PM_RUNTIME callbacks */
 extern int devfreq_suspend_device(struct devfreq *devfreq);
 extern int devfreq_resume_device(struct devfreq *devfreq);