Merge branch 'pm-devfreq'

* pm-devfreq: (23 commits)
  PM / devfreq: remove compiler error with module governors (2)
  PM / devfreq: Fix return value in devfreq_remove_governor()
  PM / devfreq: Fix incorrect argument in error message
  PM / devfreq: missing rcu_read_lock() added for find_device_opp()
  PM / devfreq: remove compiler error when a governor is module
  PM / devfreq: exynos4_bus.c: Fixed an alignment of the func call args.
  PM / devfreq: Add sysfs node to expose available governors
  PM / devfreq: allow sysfs governor node to switch governor
  PM / devfreq: governors: add GPL module license and allow module build
  PM / devfreq: map devfreq drivers to governor using name
  PM / devfreq: register governors with devfreq framework
  PM / devfreq: provide hooks for governors to be registered
  PM / devfreq: export update_devfreq
  PM / devfreq: Add sysfs node for representing frequency transition information.
  PM / devfreq: Add sysfs node to expose available frequencies
  PM / devfreq: documentation cleanups for devfreq header
  PM / devfreq: Use devm_* functions in exynos4_bus.c
  PM / devfreq: make devfreq_class static
  PM / devfreq: fix sscanf handling for writable sysfs entries
  PM / devfreq: kernel-doc typo corrections
  ...

Documentation/ABI/testing/sysfs-class-devfreq

@@ -11,7 +11,7 @@ What:		/sys/class/devfreq/.../governor
 Date:		September 2011
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
 Description:
-		The /sys/class/devfreq/.../governor shows the name of the
+		The /sys/class/devfreq/.../governor show or set the name of the
 		governor used by the corresponding devfreq object.
 
 What:		/sys/class/devfreq/.../cur_freq
@@ -19,15 +19,16 @@ Date:		September 2011
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
 Description:
 		The /sys/class/devfreq/.../cur_freq shows the current
-		frequency of the corresponding devfreq object.
+		frequency of the corresponding devfreq object. Same as
+		target_freq when get_cur_freq() is not implemented by
+		devfreq driver.
 
-What:		/sys/class/devfreq/.../central_polling
-Date:		September 2011
-Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
+What:		/sys/class/devfreq/.../target_freq
+Date:		September 2012
+Contact:	Rajagopal Venkat <rajagopal.venkat@linaro.org>
 Description:
-		The /sys/class/devfreq/.../central_polling shows whether
-		the devfreq ojbect is using devfreq-provided central
-		polling mechanism or not.
+		The /sys/class/devfreq/.../target_freq shows the next governor
+		predicted target frequency of the corresponding devfreq object.
 
 What:		/sys/class/devfreq/.../polling_interval
 Date:		September 2011
@@ -43,6 +44,17 @@ Description:
 		(/sys/class/devfreq/.../central_polling is 0), this value
 		may be useless.
 
+What:		/sys/class/devfreq/.../trans_stat
+Date:		October 2012
+Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
+Descrtiption:
+		This ABI shows the statistics of devfreq behavior on a
+		specific device. It shows the time spent in each state and
+		the number of transitions between states.
+		In order to activate this ABI, the devfreq target device
+		driver should provide the list of available frequencies
+		with its profile.
+
 What:		/sys/class/devfreq/.../userspace/set_freq
 Date:		September 2011
 Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
@@ -50,3 +62,19 @@ Description:
 		The /sys/class/devfreq/.../userspace/set_freq shows and
 		sets the requested frequency for the devfreq object if
 		userspace governor is in effect.
+
+What:		/sys/class/devfreq/.../available_frequencies
+Date:		October 2012
+Contact:	Nishanth Menon <nm@ti.com>
+Description:
+		The /sys/class/devfreq/.../available_frequencies shows
+		the available frequencies of the corresponding devfreq object.
+		This is a snapshot of available frequencies and not limited
+		by the min/max frequency restrictions.
+
+What:		/sys/class/devfreq/.../available_governors
+Date:		October 2012
+Contact:	Nishanth Menon <nm@ti.com>
+Description:
+		The /sys/class/devfreq/.../available_governors shows
+		currently available governors in the system.

drivers/devfreq/Kconfig

@@ -30,7 +30,7 @@ if PM_DEVFREQ
 comment "DEVFREQ Governors"
 
 config DEVFREQ_GOV_SIMPLE_ONDEMAND
-	bool "Simple Ondemand"
+	tristate "Simple Ondemand"
 	help
 	  Chooses frequency based on the recent load on the device. Works
 	  similar as ONDEMAND governor of CPUFREQ does. A device with
@@ -39,7 +39,7 @@ config DEVFREQ_GOV_SIMPLE_ONDEMAND
 	  values to the governor with data field at devfreq_add_device().
 
 config DEVFREQ_GOV_PERFORMANCE
-	bool "Performance"
+	tristate "Performance"
 	help
 	  Sets the frequency at the maximum available frequency.
 	  This governor always returns UINT_MAX as frequency so that
@@ -47,7 +47,7 @@ config DEVFREQ_GOV_PERFORMANCE
 	  at any time.
 
 config DEVFREQ_GOV_POWERSAVE
-	bool "Powersave"
+	tristate "Powersave"
 	help
 	  Sets the frequency at the minimum available frequency.
 	  This governor always returns 0 as frequency so that
@@ -55,7 +55,7 @@ config DEVFREQ_GOV_POWERSAVE
 	  at any time.
 
 config DEVFREQ_GOV_USERSPACE
-	bool "Userspace"
+	tristate "Userspace"
 	help
 	  Sets the frequency at the user specified one.
 	  This governor returns the user configured frequency if there

drivers/devfreq/exynos4_bus.c

@@ -987,7 +987,7 @@ static __devinit int exynos4_busfreq_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	int err = 0;
 
-	data = kzalloc(sizeof(struct busfreq_data), GFP_KERNEL);
+	data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data), GFP_KERNEL);
 	if (data == NULL) {
 		dev_err(dev, "Cannot allocate memory.\n");
 		return -ENOMEM;
@@ -1012,31 +1012,26 @@ static __devinit int exynos4_busfreq_probe(struct platform_device *pdev)
 		err = -EINVAL;
 	}
 	if (err)
-		goto err_regulator;
+		return err;
 
-	data->vdd_int = regulator_get(dev, "vdd_int");
+	data->vdd_int = devm_regulator_get(dev, "vdd_int");
 	if (IS_ERR(data->vdd_int)) {
 		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
-		err = PTR_ERR(data->vdd_int);
-		goto err_regulator;
+		return PTR_ERR(data->vdd_int);
 	}
 	if (data->type == TYPE_BUSF_EXYNOS4x12) {
-		data->vdd_mif = regulator_get(dev, "vdd_mif");
+		data->vdd_mif = devm_regulator_get(dev, "vdd_mif");
 		if (IS_ERR(data->vdd_mif)) {
 			dev_err(dev, "Cannot get the regulator \"vdd_mif\"\n");
-			err = PTR_ERR(data->vdd_mif);
-			regulator_put(data->vdd_int);
-			goto err_regulator;
-
+			return PTR_ERR(data->vdd_mif);
 		}
 	}
 
 	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;
+			exynos4_devfreq_profile.initial_freq);
+		return PTR_ERR(opp);
 	}
 	data->curr_opp = opp;
 
@@ -1045,30 +1040,20 @@ static __devinit int exynos4_busfreq_probe(struct platform_device *pdev)
 	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;
-	}
+					   "simple_ondemand", NULL);
+	if (IS_ERR(data->devfreq))
+		return PTR_ERR(data->devfreq);
 
 	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;
+		devfreq_remove_device(data->devfreq);
+		return err;
 	}
 
 	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)
@@ -1077,10 +1062,6 @@ static __devexit int exynos4_busfreq_remove(struct platform_device *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;
 }

drivers/devfreq/governor.h

@@ -18,7 +18,24 @@
 
 #define to_devfreq(DEV)	container_of((DEV), struct devfreq, dev)
 
+/* Devfreq events */
+#define DEVFREQ_GOV_START			0x1
+#define DEVFREQ_GOV_STOP			0x2
+#define DEVFREQ_GOV_INTERVAL			0x3
+#define DEVFREQ_GOV_SUSPEND			0x4
+#define DEVFREQ_GOV_RESUME			0x5
+
 /* Caution: devfreq->lock must be locked before calling update_devfreq */
 extern int update_devfreq(struct devfreq *devfreq);
 
+extern void devfreq_monitor_start(struct devfreq *devfreq);
+extern void devfreq_monitor_stop(struct devfreq *devfreq);
+extern void devfreq_monitor_suspend(struct devfreq *devfreq);
+extern void devfreq_monitor_resume(struct devfreq *devfreq);
+extern void devfreq_interval_update(struct devfreq *devfreq,
+					unsigned int *delay);
+
+extern int devfreq_add_governor(struct devfreq_governor *governor);
+extern int devfreq_remove_governor(struct devfreq_governor *governor);
+
 #endif /* _GOVERNOR_H */

drivers/devfreq/governor_performance.c

@@ -10,6 +10,7 @@
  */
 
 #include <linux/devfreq.h>
+#include <linux/module.h>
 #include "governor.h"
 
 static int devfreq_performance_func(struct devfreq *df,
@@ -26,14 +27,41 @@ static int devfreq_performance_func(struct devfreq *df,
 	return 0;
 }
 
-static int performance_init(struct devfreq *devfreq)
+static int devfreq_performance_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
 {
-	return update_devfreq(devfreq);
+	int ret = 0;
+
+	if (event == DEVFREQ_GOV_START) {
+		mutex_lock(&devfreq->lock);
+		ret = update_devfreq(devfreq);
+		mutex_unlock(&devfreq->lock);
+	}
+
+	return ret;
 }
 
-const struct devfreq_governor devfreq_performance = {
+static struct devfreq_governor devfreq_performance = {
 	.name = "performance",
-	.init = performance_init,
 	.get_target_freq = devfreq_performance_func,
-	.no_central_polling = true,
+	.event_handler = devfreq_performance_handler,
 };
+
+static int __init devfreq_performance_init(void)
+{
+	return devfreq_add_governor(&devfreq_performance);
+}
+subsys_initcall(devfreq_performance_init);
+
+static void __exit devfreq_performance_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_performance);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_performance_exit);
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_powersave.c

@@ -10,6 +10,7 @@
  */
 
 #include <linux/devfreq.h>
+#include <linux/module.h>
 #include "governor.h"
 
 static int devfreq_powersave_func(struct devfreq *df,
@@ -23,14 +24,41 @@ static int devfreq_powersave_func(struct devfreq *df,
 	return 0;
 }
 
-static int powersave_init(struct devfreq *devfreq)
+static int devfreq_powersave_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
 {
-	return update_devfreq(devfreq);
+	int ret = 0;
+
+	if (event == DEVFREQ_GOV_START) {
+		mutex_lock(&devfreq->lock);
+		ret = update_devfreq(devfreq);
+		mutex_unlock(&devfreq->lock);
+	}
+
+	return ret;
 }
 
-const struct devfreq_governor devfreq_powersave = {
+static struct devfreq_governor devfreq_powersave = {
 	.name = "powersave",
-	.init = powersave_init,
 	.get_target_freq = devfreq_powersave_func,
-	.no_central_polling = true,
+	.event_handler = devfreq_powersave_handler,
 };
+
+static int __init devfreq_powersave_init(void)
+{
+	return devfreq_add_governor(&devfreq_powersave);
+}
+subsys_initcall(devfreq_powersave_init);
+
+static void __exit devfreq_powersave_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_powersave);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_powersave_exit);
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_simpleondemand.c

@@ -10,8 +10,10 @@
  */
 
 #include <linux/errno.h>
+#include <linux/module.h>
 #include <linux/devfreq.h>
 #include <linux/math64.h>
+#include "governor.h"
 
 /* Default constants for DevFreq-Simple-Ondemand (DFSO) */
 #define DFSO_UPTHRESHOLD	(90)
@@ -88,7 +90,58 @@ static int devfreq_simple_ondemand_func(struct devfreq *df,
 	return 0;
 }
 
-const struct devfreq_governor devfreq_simple_ondemand = {
+static int devfreq_simple_ondemand_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		devfreq_monitor_start(devfreq);
+		break;
+
+	case DEVFREQ_GOV_STOP:
+		devfreq_monitor_stop(devfreq);
+		break;
+
+	case DEVFREQ_GOV_INTERVAL:
+		devfreq_interval_update(devfreq, (unsigned int *)data);
+		break;
+
+	case DEVFREQ_GOV_SUSPEND:
+		devfreq_monitor_suspend(devfreq);
+		break;
+
+	case DEVFREQ_GOV_RESUME:
+		devfreq_monitor_resume(devfreq);
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct devfreq_governor devfreq_simple_ondemand = {
 	.name = "simple_ondemand",
 	.get_target_freq = devfreq_simple_ondemand_func,
+	.event_handler = devfreq_simple_ondemand_handler,
 };
+
+static int __init devfreq_simple_ondemand_init(void)
+{
+	return devfreq_add_governor(&devfreq_simple_ondemand);
+}
+subsys_initcall(devfreq_simple_ondemand_init);
+
+static void __exit devfreq_simple_ondemand_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_simple_ondemand);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_simple_ondemand_exit);
+MODULE_LICENSE("GPL");

drivers/devfreq/governor_userspace.c

@@ -14,6 +14,7 @@
 #include <linux/devfreq.h>
 #include <linux/pm.h>
 #include <linux/mutex.h>
+#include <linux/module.h>
 #include "governor.h"
 
 struct userspace_data {
@@ -116,10 +117,46 @@ static void userspace_exit(struct devfreq *devfreq)
 	devfreq->data = NULL;
 }
 
-const struct devfreq_governor devfreq_userspace = {
+static int devfreq_userspace_handler(struct devfreq *devfreq,
+			unsigned int event, void *data)
+{
+	int ret = 0;
+
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		ret = userspace_init(devfreq);
+		break;
+	case DEVFREQ_GOV_STOP:
+		userspace_exit(devfreq);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_userspace = {
 	.name = "userspace",
 	.get_target_freq = devfreq_userspace_func,
-	.init = userspace_init,
-	.exit = userspace_exit,
-	.no_central_polling = true,
+	.event_handler = devfreq_userspace_handler,
 };
+
+static int __init devfreq_userspace_init(void)
+{
+	return devfreq_add_governor(&devfreq_userspace);
+}
+subsys_initcall(devfreq_userspace_init);
+
+static void __exit devfreq_userspace_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_userspace);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+
+	return;
+}
+module_exit(devfreq_userspace_exit);
+MODULE_LICENSE("GPL");

include/linux/devfreq.h

@@ -25,12 +25,12 @@ struct devfreq;
  * struct devfreq_dev_status - Data given from devfreq user device to
  *			     governors. Represents the performance
  *			     statistics.
- * @total_time		The total time represented by this instance of
+ * @total_time:		The total time represented by this instance of
  *			devfreq_dev_status
- * @busy_time		The time that the device was working among the
+ * @busy_time:		The time that the device was working among the
  *			total_time.
- * @current_frequency	The operating frequency.
- * @private_data	An entry not specified by the devfreq framework.
+ * @current_frequency:	The operating frequency.
+ * @private_data:	An entry not specified by the devfreq framework.
  *			A device and a specific governor may have their
  *			own protocol with private_data. However, because
  *			this is governor-specific, a governor using this
@@ -54,23 +54,27 @@ struct devfreq_dev_status {
 
 /**
  * struct devfreq_dev_profile - Devfreq's user device profile
- * @initial_freq	The operating frequency when devfreq_add_device() is
+ * @initial_freq:	The operating frequency when devfreq_add_device() is
  *			called.
- * @polling_ms		The polling interval in ms. 0 disables polling.
- * @target		The device should set its operating frequency at
+ * @polling_ms:		The polling interval in ms. 0 disables polling.
+ * @target:		The device should set its operating frequency at
  *			freq or lowest-upper-than-freq value. If freq is
  *			higher than any operable frequency, set maximum.
  *			Before returning, target function should set
  *			freq at the current frequency.
  *			The "flags" parameter's possible values are
  *			explained above with "DEVFREQ_FLAG_*" macros.
- * @get_dev_status	The device should provide the current performance
+ * @get_dev_status:	The device should provide the current performance
  *			status to devfreq, which is used by governors.
- * @exit		An optional callback that is called when devfreq
+ * @get_cur_freq:	The device should provide the current frequency
+ *			at which it is operating.
+ * @exit:		An optional callback that is called when devfreq
  *			is removing the devfreq object due to error or
  *			from devfreq_remove_device() call. If the user
  *			has registered devfreq->nb at a notifier-head,
  *			this is the time to unregister it.
+ * @freq_table:	Optional list of frequencies to support statistics.
+ * @max_state:	The size of freq_table.
  */
 struct devfreq_dev_profile {
 	unsigned long initial_freq;
@@ -79,63 +83,63 @@ struct devfreq_dev_profile {
 	int (*target)(struct device *dev, unsigned long *freq, u32 flags);
 	int (*get_dev_status)(struct device *dev,
 			      struct devfreq_dev_status *stat);
+	int (*get_cur_freq)(struct device *dev, unsigned long *freq);
 	void (*exit)(struct device *dev);
+
+	unsigned int *freq_table;
+	unsigned int max_state;
 };
 
 /**
  * struct devfreq_governor - Devfreq policy governor
- * @name		Governor's name
- * @get_target_freq	Returns desired operating frequency for the device.
+ * @node:		list node - contains registered devfreq governors
+ * @name:		Governor's name
+ * @get_target_freq:	Returns desired operating frequency for the device.
  *			Basically, get_target_freq will run
  *			devfreq_dev_profile.get_dev_status() to get the
  *			status of the device (load = busy_time / total_time).
  *			If no_central_polling is set, this callback is called
  *			only with update_devfreq() notified by OPP.
- * @init		Called when the devfreq is being attached to a device
- * @exit		Called when the devfreq is being removed from a
- *			device. Governor should stop any internal routines
- *			before return because related data may be
- *			freed after exit().
- * @no_central_polling	Do not use devfreq's central polling mechanism.
- *			When this is set, devfreq will not call
- *			get_target_freq with devfreq_monitor(). However,
- *			devfreq will call get_target_freq with
- *			devfreq_update() notified by OPP framework.
+ * @event_handler:      Callback for devfreq core framework to notify events
+ *                      to governors. Events include per device governor
+ *                      init and exit, opp changes out of devfreq, suspend
+ *                      and resume of per device devfreq during device idle.
  *
  * Note that the callbacks are called with devfreq->lock locked by devfreq.
  */
 struct devfreq_governor {
+	struct list_head node;
+
 	const char name[DEVFREQ_NAME_LEN];
 	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
-	int (*init)(struct devfreq *this);
-	void (*exit)(struct devfreq *this);
-	const bool no_central_polling;
+	int (*event_handler)(struct devfreq *devfreq,
+				unsigned int event, void *data);
 };
 
 /**
  * struct devfreq - Device devfreq structure
- * @node	list node - contains the devices with devfreq that have been
+ * @node:	list node - contains the devices with devfreq that have been
  *		registered.
- * @lock	a mutex to protect accessing devfreq.
- * @dev		device registered by devfreq class. dev.parent is the device
+ * @lock:	a mutex to protect accessing devfreq.
+ * @dev:	device registered by devfreq class. dev.parent is the device
  *		using devfreq.
- * @profile	device-specific devfreq profile
- * @governor	method how to choose frequency based on the usage.
- * @nb		notifier block used to notify devfreq object that it should
+ * @profile:	device-specific devfreq profile
+ * @governor:	method how to choose frequency based on the usage.
+ * @governor_name:	devfreq governor name for use with this devfreq
+ * @nb:		notifier block used to notify devfreq object that it should
  *		reevaluate operable frequencies. Devfreq users may use
  *		devfreq.nb to the corresponding register notifier call chain.
- * @polling_jiffies	interval in jiffies.
- * @previous_freq	previously configured frequency value.
- * @next_polling	the number of remaining jiffies to poll with
- *			"devfreq_monitor" executions to reevaluate
- *			frequency/voltage of the device. Set by
- *			profile's polling_ms interval.
- * @data	Private data of the governor. The devfreq framework does not
+ * @work:	delayed work for load monitoring.
+ * @previous_freq:	previously configured frequency value.
+ * @data:	Private data of the governor. The devfreq framework does not
  *		touch this.
- * @being_removed	a flag to mark that this object is being removed in
- *			order to prevent trying to remove the object multiple times.
- * @min_freq	Limit minimum frequency requested by user (0: none)
- * @max_freq	Limit maximum frequency requested by user (0: none)
+ * @min_freq:	Limit minimum frequency requested by user (0: none)
+ * @max_freq:	Limit maximum frequency requested by user (0: none)
+ * @stop_polling:	 devfreq polling status of a device.
+ * @total_trans:	Number of devfreq transitions
+ * @trans_table:	Statistics of devfreq transitions
+ * @time_in_state:	Statistics of devfreq states
+ * @last_stat_updated:	The last time stat updated
  *
  * This structure stores the devfreq information for a give device.
  *
@@ -152,26 +156,33 @@ struct devfreq {
 	struct device dev;
 	struct devfreq_dev_profile *profile;
 	const struct devfreq_governor *governor;
+	char governor_name[DEVFREQ_NAME_LEN];
 	struct notifier_block nb;
+	struct delayed_work work;
 
-	unsigned long polling_jiffies;
 	unsigned long previous_freq;
-	unsigned int next_polling;
 
 	void *data; /* private data for governors */
 
-	bool being_removed;
-
 	unsigned long min_freq;
 	unsigned long max_freq;
+	bool stop_polling;
+
+	/* information for device freqeuncy transition */
+	unsigned int total_trans;
+	unsigned int *trans_table;
+	unsigned long *time_in_state;
+	unsigned long last_stat_updated;
 };
 
 #if defined(CONFIG_PM_DEVFREQ)
 extern struct devfreq *devfreq_add_device(struct device *dev,
 				  struct devfreq_dev_profile *profile,
-				  const struct devfreq_governor *governor,
+				  const char *governor_name,
 				  void *data);
 extern int devfreq_remove_device(struct devfreq *devfreq);
+extern int devfreq_suspend_device(struct devfreq *devfreq);
+extern int devfreq_resume_device(struct devfreq *devfreq);
 
 /* Helper functions for devfreq user device driver with OPP. */
 extern struct opp *devfreq_recommended_opp(struct device *dev,
@@ -181,23 +192,13 @@ extern int devfreq_register_opp_notifier(struct device *dev,
 extern int devfreq_unregister_opp_notifier(struct device *dev,
 					   struct devfreq *devfreq);
 
-#ifdef CONFIG_DEVFREQ_GOV_POWERSAVE
-extern const struct devfreq_governor devfreq_powersave;
-#endif
-#ifdef CONFIG_DEVFREQ_GOV_PERFORMANCE
-extern const struct devfreq_governor devfreq_performance;
-#endif
-#ifdef CONFIG_DEVFREQ_GOV_USERSPACE
-extern const struct devfreq_governor devfreq_userspace;
-#endif
-#ifdef CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND
-extern const struct devfreq_governor devfreq_simple_ondemand;
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
 /**
  * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
  *	and devfreq_add_device
- * @ upthreshold	If the load is over this value, the frequency jumps.
+ * @upthreshold:	If the load is over this value, the frequency jumps.
  *			Specify 0 to use the default. Valid value = 0 to 100.
- * @ downdifferential	If the load is under upthreshold - downdifferential,
+ * @downdifferential:	If the load is under upthreshold - downdifferential,
  *			the governor may consider slowing the frequency down.
  *			Specify 0 to use the default. Valid value = 0 to 100.
  *			downdifferential < upthreshold must hold.
@@ -214,7 +215,7 @@ struct devfreq_simple_ondemand_data {
 #else /* !CONFIG_PM_DEVFREQ */
 static struct devfreq *devfreq_add_device(struct device *dev,
 					  struct devfreq_dev_profile *profile,
-					  struct devfreq_governor *governor,
+					  const char *governor_name,
 					  void *data)
 {
 	return NULL;
@@ -225,6 +226,16 @@ static int devfreq_remove_device(struct devfreq *devfreq)
 	return 0;
 }
 
+static int devfreq_suspend_device(struct devfreq *devfreq)
+{
+	return 0;
+}
+
+static int devfreq_resume_device(struct devfreq *devfreq)
+{
+	return 0;
+}
+
 static struct opp *devfreq_recommended_opp(struct device *dev,
 					   unsigned long *freq, u32 flags)
 {
@@ -243,11 +254,6 @@ static int devfreq_unregister_opp_notifier(struct device *dev,
 	return -EINVAL;
 }
 
-#define devfreq_powersave	NULL
-#define devfreq_performance	NULL
-#define devfreq_userspace	NULL
-#define devfreq_simple_ondemand	NULL
-
 #endif /* CONFIG_PM_DEVFREQ */
 
 #endif /* __LINUX_DEVFREQ_H__ */