[linux-block.git] / include / linux / devfreq.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
 *	    for Non-CPU Devices.
 *
 * Copyright (C) 2011 Samsung Electronics
 *	MyungJoo Ham <myungjoo.ham@samsung.com>
 */

#ifndef __LINUX_DEVFREQ_H__
#define __LINUX_DEVFREQ_H__

#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/pm_opp.h>
#include <linux/pm_qos.h>

/* DEVFREQ governor name */
#define DEVFREQ_GOV_SIMPLE_ONDEMAND	"simple_ondemand"
#define DEVFREQ_GOV_PERFORMANCE		"performance"
#define DEVFREQ_GOV_POWERSAVE		"powersave"
#define DEVFREQ_GOV_USERSPACE		"userspace"
#define DEVFREQ_GOV_PASSIVE		"passive"

/* DEVFREQ notifier interface */
#define DEVFREQ_TRANSITION_NOTIFIER	(0)

/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
#define	DEVFREQ_PRECHANGE		(0)
#define DEVFREQ_POSTCHANGE		(1)

/* DEVFREQ work timers */
enum devfreq_timer {
	DEVFREQ_TIMER_DEFERRABLE = 0,
	DEVFREQ_TIMER_DELAYED,
	DEVFREQ_TIMER_NUM,
};

struct devfreq;
struct devfreq_governor;
struct devfreq_cpu_data;
struct thermal_cooling_device;

/**
 * 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
 *			devfreq_dev_status
 * @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.
 *			A device and a specific governor may have their
 *			own protocol with private_data. However, because
 *			this is governor-specific, a governor using this
 *			will be only compatible with devices aware of it.
 */
struct devfreq_dev_status {
	/* both since the last measure */
	unsigned long total_time;
	unsigned long busy_time;
	unsigned long current_frequency;
	void *private_data;
};

/*
 * The resulting frequency should be at most this. (this bound is the
 * least upper bound; thus, the resulting freq should be lower or same)
 * If the flag is not set, the resulting frequency should be at most the
 * bound (greatest lower bound)
 */
#define DEVFREQ_FLAG_LEAST_UPPER_BOUND		0x1

/**
 * struct devfreq_dev_profile - Devfreq's user device profile
 * @initial_freq:	The operating frequency when devfreq_add_device() is
 *			called.
 * @polling_ms:		The polling interval in ms. 0 disables polling.
 * @timer:		Timer type is either deferrable or delayed timer.
 * @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
 *			status to devfreq. Governors are recommended not to
 *			use this directly. Instead, governors are recommended
 *			to use devfreq_update_stats() along with
 *			devfreq.last_status.
 * @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
 *			and freq_table must be generated in ascending order.
 * @max_state:		The size of freq_table.
 *
 * @is_cooling_device: A self-explanatory boolean giving the device a
 *                     cooling effect property.
 */
struct devfreq_dev_profile {
	unsigned long initial_freq;
	unsigned int polling_ms;
	enum devfreq_timer timer;
	bool is_cooling_device;

	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 long *freq_table;
	unsigned int max_state;
};

/**
 * struct devfreq_stats - Statistics of devfreq device behavior
 * @total_trans:	Number of devfreq transitions.
 * @trans_table:	Statistics of devfreq transitions.
 * @time_in_state:	Statistics of devfreq states.
 * @last_update:	The last time stats were updated.
 */
struct devfreq_stats {
	unsigned int total_trans;
	unsigned int *trans_table;
	u64 *time_in_state;
	u64 last_update;
};

/**
 * struct devfreq - Device devfreq structure
 * @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
 *		using devfreq.
 * @profile:	device-specific devfreq profile
 * @governor:	method how to choose frequency based on the usage.
 * @opp_table:	Reference to OPP table of dev.parent, if one exists.
 * @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.
 * @work:	delayed work for load monitoring.
 * @previous_freq:	previously configured frequency value.
 * @last_status:	devfreq user device info, performance statistics
 * @data:	Private data of the governor. The devfreq framework does not
 *		touch this.
 * @user_min_freq_req:	PM QoS minimum frequency request from user (via sysfs)
 * @user_max_freq_req:	PM QoS maximum frequency request from user (via sysfs)
 * @scaling_min_freq:	Limit minimum frequency requested by OPP interface
 * @scaling_max_freq:	Limit maximum frequency requested by OPP interface
 * @stop_polling:	 devfreq polling status of a device.
 * @suspend_freq:	 frequency of a device set during suspend phase.
 * @resume_freq:	 frequency of a device set in resume phase.
 * @suspend_count:	 suspend requests counter for a device.
 * @stats:	Statistics of devfreq device behavior
 * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
 * @cdev:	Cooling device pointer if the devfreq has cooling property
 * @nb_min:		Notifier block for DEV_PM_QOS_MIN_FREQUENCY
 * @nb_max:		Notifier block for DEV_PM_QOS_MAX_FREQUENCY
 *
 * This structure stores the devfreq information for a given device.
 *
 * Note that when a governor accesses entries in struct devfreq in its
 * functions except for the context of callbacks defined in struct
 * devfreq_governor, the governor should protect its access with the
 * struct mutex lock in struct devfreq. A governor may use this mutex
 * to protect its own private data in ``void *data`` as well.
 */
struct devfreq {
	struct list_head node;

	struct mutex lock;
	struct device dev;
	struct devfreq_dev_profile *profile;
	const struct devfreq_governor *governor;
	struct opp_table *opp_table;
	struct notifier_block nb;
	struct delayed_work work;

	unsigned long previous_freq;
	struct devfreq_dev_status last_status;

	void *data; /* private data for governors */

	struct dev_pm_qos_request user_min_freq_req;
	struct dev_pm_qos_request user_max_freq_req;
	unsigned long scaling_min_freq;
	unsigned long scaling_max_freq;
	bool stop_polling;

	unsigned long suspend_freq;
	unsigned long resume_freq;
	atomic_t suspend_count;

	/* information for device frequency transitions */
	struct devfreq_stats stats;

	struct srcu_notifier_head transition_notifier_list;

	/* Pointer to the cooling device if used for thermal mitigation */
	struct thermal_cooling_device *cdev;

	struct notifier_block nb_min;
	struct notifier_block nb_max;
};

struct devfreq_freqs {
	unsigned long old;
	unsigned long new;
};

#if defined(CONFIG_PM_DEVFREQ)
struct devfreq *devfreq_add_device(struct device *dev,
				struct devfreq_dev_profile *profile,
				const char *governor_name,
				void *data);
int devfreq_remove_device(struct devfreq *devfreq);
struct devfreq *devm_devfreq_add_device(struct device *dev,
				struct devfreq_dev_profile *profile,
				const char *governor_name,
				void *data);
void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq);

/* Supposed to be called by PM callbacks */
int devfreq_suspend_device(struct devfreq *devfreq);
int devfreq_resume_device(struct devfreq *devfreq);

void devfreq_suspend(void);
void devfreq_resume(void);

/* update_devfreq() - Reevaluate the device and configure frequency */
int update_devfreq(struct devfreq *devfreq);

/* Helper functions for devfreq user device driver with OPP. */
struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
				unsigned long *freq, u32 flags);
int devfreq_register_opp_notifier(struct device *dev,
				struct devfreq *devfreq);
int devfreq_unregister_opp_notifier(struct device *dev,
				struct devfreq *devfreq);
int devm_devfreq_register_opp_notifier(struct device *dev,
				struct devfreq *devfreq);
void devm_devfreq_unregister_opp_notifier(struct device *dev,
				struct devfreq *devfreq);
int devfreq_register_notifier(struct devfreq *devfreq,
				struct notifier_block *nb,
				unsigned int list);
int devfreq_unregister_notifier(struct devfreq *devfreq,
				struct notifier_block *nb,
				unsigned int list);
int devm_devfreq_register_notifier(struct device *dev,
				struct devfreq *devfreq,
				struct notifier_block *nb,
				unsigned int list);
void devm_devfreq_unregister_notifier(struct device *dev,
				struct devfreq *devfreq,
				struct notifier_block *nb,
				unsigned int list);
struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node);
struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
				const char *phandle_name, int index);

#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.
 *			Specify 0 to use the default. Valid value = 0 to 100.
 * @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.
 *
 * If the fed devfreq_simple_ondemand_data pointer is NULL to the governor,
 * the governor uses the default values.
 */
struct devfreq_simple_ondemand_data {
	unsigned int upthreshold;
	unsigned int downdifferential;
};
#endif

#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
enum devfreq_parent_dev_type {
	DEVFREQ_PARENT_DEV,
	CPUFREQ_PARENT_DEV,
};

/**
 * struct devfreq_passive_data - ``void *data`` fed to struct devfreq
 *	and devfreq_add_device
 * @parent:	the devfreq instance of parent device.
 * @get_target_freq:	Optional callback, Returns desired operating frequency
 *			for the device using passive governor. That is called
 *			when passive governor should decide the next frequency
 *			by using the new frequency of parent devfreq device
 *			using governors except for passive governor.
 *			If the devfreq device has the specific method to decide
 *			the next frequency, should use this callback.
 * @parent_type:	the parent type of the device.
 * @this:		the devfreq instance of own device.
 * @nb:			the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
 *			CPUFREQ_TRANSITION_NOTIFIER list.
 * @cpu_data_list:	the list of cpu frequency data for all cpufreq_policy.
 *
 * The devfreq_passive_data have to set the devfreq instance of parent
 * device with governors except for the passive governor. But, don't need to
 * initialize the 'this' and 'nb' field because the devfreq core will handle
 * them.
 */
struct devfreq_passive_data {
	/* Should set the devfreq instance of parent device */
	struct devfreq *parent;

	/* Optional callback to decide the next frequency of passvice device */
	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);

	/* Should set the type of parent device */
	enum devfreq_parent_dev_type parent_type;

	/* For passive governor's internal use. Don't need to set them */
	struct devfreq *this;
	struct notifier_block nb;
	struct list_head cpu_data_list;
};
#endif

#else /* !CONFIG_PM_DEVFREQ */
static inline struct devfreq *devfreq_add_device(struct device *dev,
					struct devfreq_dev_profile *profile,
					const char *governor_name,
					void *data)
{
	return ERR_PTR(-ENOSYS);
}

static inline int devfreq_remove_device(struct devfreq *devfreq)
{
	return 0;
}

static inline struct devfreq *devm_devfreq_add_device(struct device *dev,
					struct devfreq_dev_profile *profile,
					const char *governor_name,
					void *data)
{
	return ERR_PTR(-ENOSYS);
}

static inline void devm_devfreq_remove_device(struct device *dev,
					struct devfreq *devfreq)
{
}

static inline int devfreq_suspend_device(struct devfreq *devfreq)
{
	return 0;
}

static inline int devfreq_resume_device(struct devfreq *devfreq)
{
	return 0;
}

static inline void devfreq_suspend(void) {}
static inline void devfreq_resume(void) {}

static inline struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
					unsigned long *freq, u32 flags)
{
	return ERR_PTR(-EINVAL);
}

static inline int devfreq_register_opp_notifier(struct device *dev,
					struct devfreq *devfreq)
{
	return -EINVAL;
}

static inline int devfreq_unregister_opp_notifier(struct device *dev,
					struct devfreq *devfreq)
{
	return -EINVAL;
}

static inline int devm_devfreq_register_opp_notifier(struct device *dev,
					struct devfreq *devfreq)
{
	return -EINVAL;
}

static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
					struct devfreq *devfreq)
{
}

static inline int devfreq_register_notifier(struct devfreq *devfreq,
					struct notifier_block *nb,
					unsigned int list)
{
	return 0;
}

static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
					struct notifier_block *nb,
					unsigned int list)
{
	return 0;
}

static inline int devm_devfreq_register_notifier(struct device *dev,
					struct devfreq *devfreq,
					struct notifier_block *nb,
					unsigned int list)
{
	return 0;
}

static inline void devm_devfreq_unregister_notifier(struct device *dev,
					struct devfreq *devfreq,
					struct notifier_block *nb,
					unsigned int list)
{
}

static inline struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
{
	return ERR_PTR(-ENODEV);
}

static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
					const char *phandle_name, int index)
{
	return ERR_PTR(-ENODEV);
}

static inline int devfreq_update_stats(struct devfreq *df)
{
	return -EINVAL;
}
#endif /* CONFIG_PM_DEVFREQ */

#endif /* __LINUX_DEVFREQ_H__ */
Commit	Line	Data
d2912cb1	1	/* SPDX-License-Identifier: GPL-2.0-only */
a3c98b8b MH	2	/*
	3	* devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
	4	* for Non-CPU Devices.
	5	*
	6	* Copyright (C) 2011 Samsung Electronics
	7	* MyungJoo Ham <myungjoo.ham@samsung.com>
a3c98b8b MH	8	*/
	9
	10	#ifndef __LINUX_DEVFREQ_H__
	11	#define __LINUX_DEVFREQ_H__
	12
	13	#include <linux/device.h>
	14	#include <linux/notifier.h>
e4db1c74	15	#include <linux/pm_opp.h>
27dbc542	16	#include <linux/pm_qos.h>
a3c98b8b	17
aa7c352f CC	18	/* DEVFREQ governor name */
	19	#define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand"
	20	#define DEVFREQ_GOV_PERFORMANCE "performance"
	21	#define DEVFREQ_GOV_POWERSAVE "powersave"
	22	#define DEVFREQ_GOV_USERSPACE "userspace"
	23	#define DEVFREQ_GOV_PASSIVE "passive"
	24
0fe3a664 CC	25	/* DEVFREQ notifier interface */
	26	#define DEVFREQ_TRANSITION_NOTIFIER (0)
	27
	28	/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
	29	#define DEVFREQ_PRECHANGE (0)
	30	#define DEVFREQ_POSTCHANGE (1)
	31
4dc3bab8 CC	32	/* DEVFREQ work timers */
	33	enum devfreq_timer {
	34	DEVFREQ_TIMER_DEFERRABLE = 0,
	35	DEVFREQ_TIMER_DELAYED,
	36	DEVFREQ_TIMER_NUM,
	37	};
	38
a3c98b8b	39	struct devfreq;
3ea6b700	40	struct devfreq_governor;
a03dacb0	41	struct devfreq_cpu_data;
1224451b	42	struct thermal_cooling_device;
a3c98b8b MH	43
	44	/**
	45	* struct devfreq_dev_status - Data given from devfreq user device to
	46	* governors. Represents the performance
	47	* statistics.
e09651fc	48	* @total_time: The total time represented by this instance of
a3c98b8b	49	* devfreq_dev_status
e09651fc	50	* @busy_time: The time that the device was working among the
a3c98b8b	51	* total_time.
e09651fc NM	52	* @current_frequency: The operating frequency.
e09651fc NM	53	* @private_data: An entry not specified by the devfreq framework.
a3c98b8b MH	54	* A device and a specific governor may have their
	55	* own protocol with private_data. However, because
	56	* this is governor-specific, a governor using this
	57	* will be only compatible with devices aware of it.
	58	*/
	59	struct devfreq_dev_status {
	60	/* both since the last measure */
	61	unsigned long total_time;
	62	unsigned long busy_time;
	63	unsigned long current_frequency;
1a51cfdc	64	void *private_data;
a3c98b8b MH	65	};
a3c98b8b MH	66
ab5f299f MH	67	/*
	68	* The resulting frequency should be at most this. (this bound is the
	69	* least upper bound; thus, the resulting freq should be lower or same)
	70	* If the flag is not set, the resulting frequency should be at most the
	71	* bound (greatest lower bound)
	72	*/
	73	#define DEVFREQ_FLAG_LEAST_UPPER_BOUND 0x1
	74
a3c98b8b MH	75	/**
a3c98b8b MH	76	* struct devfreq_dev_profile - Devfreq's user device profile
e09651fc	77	* @initial_freq: The operating frequency when devfreq_add_device() is
a3c98b8b	78	* called.
e09651fc	79	* @polling_ms: The polling interval in ms. 0 disables polling.
4dc3bab8	80	* @timer: Timer type is either deferrable or delayed timer.
e09651fc	81	* @target: The device should set its operating frequency at
a3c98b8b MH	82	* freq or lowest-upper-than-freq value. If freq is
	83	* higher than any operable frequency, set maximum.
	84	* Before returning, target function should set
	85	* freq at the current frequency.
ab5f299f MH	86	* The "flags" parameter's possible values are
ab5f299f MH	87	* explained above with "DEVFREQ_FLAG_*" macros.
e09651fc	88	* @get_dev_status: The device should provide the current performance
d54cdf3f MH	89	* status to devfreq. Governors are recommended not to
	90	* use this directly. Instead, governors are recommended
	91	* to use devfreq_update_stats() along with
	92	* devfreq.last_status.
e09651fc	93	* @get_cur_freq: The device should provide the current frequency
7f98a905	94	* at which it is operating.
e09651fc	95	* @exit: An optional callback that is called when devfreq
a3c98b8b MH	96	* is removing the devfreq object due to error or
	97	* from devfreq_remove_device() call. If the user
	98	* has registered devfreq->nb at a notifier-head,
	99	* this is the time to unregister it.
416b46a2 CC	100	* @freq_table: Optional list of frequencies to support statistics
	101	* and freq_table must be generated in ascending order.
	102	* @max_state: The size of freq_table.
1224451b DL	103	*
	104	* @is_cooling_device: A self-explanatory boolean giving the device a
	105	* cooling effect property.
a3c98b8b MH	106	*/
	107	struct devfreq_dev_profile {
	108	unsigned long initial_freq;
	109	unsigned int polling_ms;
4dc3bab8	110	enum devfreq_timer timer;
1224451b	111	bool is_cooling_device;
a3c98b8b	112
ab5f299f	113	int (target)(struct device dev, unsigned long *freq, u32 flags);
a3c98b8b MH	114	int (get_dev_status)(struct device dev,
a3c98b8b MH	115	struct devfreq_dev_status *stat);
7f98a905	116	int (get_cur_freq)(struct device dev, unsigned long *freq);
a3c98b8b	117	void (exit)(struct device dev);
e552bbaf	118
0ec09ac2	119	unsigned long *freq_table;
e552bbaf	120	unsigned int max_state;
a3c98b8b MH	121	};
a3c98b8b MH	122
1ebd0bc0 KK	123	/**
	124	* struct devfreq_stats - Statistics of devfreq device behavior
	125	* @total_trans: Number of devfreq transitions.
	126	* @trans_table: Statistics of devfreq transitions.
	127	* @time_in_state: Statistics of devfreq states.
	128	* @last_update: The last time stats were updated.
	129	*/
	130	struct devfreq_stats {
	131	unsigned int total_trans;
	132	unsigned int *trans_table;
	133	u64 *time_in_state;
	134	u64 last_update;
	135	};
	136
a3c98b8b MH	137	/**
a3c98b8b MH	138	* struct devfreq - Device devfreq structure
e09651fc	139	* @node: list node - contains the devices with devfreq that have been
a3c98b8b	140	* registered.
e09651fc NM	141	* @lock: a mutex to protect accessing devfreq.
e09651fc NM	142	* @dev: device registered by devfreq class. dev.parent is the device
a3c98b8b	143	* using devfreq.
e09651fc NM	144	* @profile: device-specific devfreq profile
e09651fc NM	145	* @governor: method how to choose frequency based on the usage.
26f9c7cc	146	* @opp_table: Reference to OPP table of dev.parent, if one exists.
e09651fc	147	* @nb: notifier block used to notify devfreq object that it should
a3c98b8b MH	148	* reevaluate operable frequencies. Devfreq users may use
a3c98b8b MH	149	* devfreq.nb to the corresponding register notifier call chain.
e09651fc NM	150	* @work: delayed work for load monitoring.
e09651fc NM	151	* @previous_freq: previously configured frequency value.
54cb5740	152	* @last_status: devfreq user device info, performance statistics
e09651fc	153	* @data: Private data of the governor. The devfreq framework does not
a3c98b8b	154	* touch this.
27dbc542 LC	155	* @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs)
27dbc542 LC	156	* @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs)
f1d981ea CC	157	* @scaling_min_freq: Limit minimum frequency requested by OPP interface
f1d981ea CC	158	* @scaling_max_freq: Limit maximum frequency requested by OPP interface
e09651fc	159	* @stop_polling: devfreq polling status of a device.
83f8ca45 LL	160	* @suspend_freq: frequency of a device set during suspend phase.
	161	* @resume_freq: frequency of a device set in resume phase.
	162	* @suspend_count: suspend requests counter for a device.
1ebd0bc0	163	* @stats: Statistics of devfreq device behavior
0fe3a664	164	* @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
1224451b	165	* @cdev: Cooling device pointer if the devfreq has cooling property
05d7ae15 LC	166	* @nb_min: Notifier block for DEV_PM_QOS_MIN_FREQUENCY
05d7ae15 LC	167	* @nb_max: Notifier block for DEV_PM_QOS_MAX_FREQUENCY
a3c98b8b	168	*
54cb5740	169	* This structure stores the devfreq information for a given device.
a3c98b8b MH	170	*
	171	* Note that when a governor accesses entries in struct devfreq in its
	172	* functions except for the context of callbacks defined in struct
	173	* devfreq_governor, the governor should protect its access with the
	174	* struct mutex lock in struct devfreq. A governor may use this mutex
7a51320e	175	* to protect its own private data in ``void *data`` as well.
a3c98b8b MH	176	*/
	177	struct devfreq {
	178	struct list_head node;
	179
	180	struct mutex lock;
	181	struct device dev;
	182	struct devfreq_dev_profile *profile;
	183	const struct devfreq_governor *governor;
26f9c7cc	184	struct opp_table *opp_table;
a3c98b8b	185	struct notifier_block nb;
7e6fdd4b	186	struct delayed_work work;
a3c98b8b	187
a3c98b8b	188	unsigned long previous_freq;
08e75e75	189	struct devfreq_dev_status last_status;
a3c98b8b MH	190
	191	void data; / private data for governors */
	192
27dbc542 LC	193	struct dev_pm_qos_request user_min_freq_req;
27dbc542 LC	194	struct dev_pm_qos_request user_max_freq_req;
f1d981ea CC	195	unsigned long scaling_min_freq;
f1d981ea CC	196	unsigned long scaling_max_freq;
7e6fdd4b	197	bool stop_polling;
e552bbaf	198
83f8ca45 LL	199	unsigned long suspend_freq;
	200	unsigned long resume_freq;
	201	atomic_t suspend_count;
	202
1ebd0bc0 KK	203	/* information for device frequency transitions */
1ebd0bc0 KK	204	struct devfreq_stats stats;
0fe3a664 CC	205
0fe3a664 CC	206	struct srcu_notifier_head transition_notifier_list;
05d7ae15	207
1224451b DL	208	/* Pointer to the cooling device if used for thermal mitigation */
	209	struct thermal_cooling_device *cdev;
	210
05d7ae15 LC	211	struct notifier_block nb_min;
05d7ae15 LC	212	struct notifier_block nb_max;
0fe3a664 CC	213	};
	214
	215	struct devfreq_freqs {
	216	unsigned long old;
	217	unsigned long new;
a3c98b8b MH	218	};
	219
	220	#if defined(CONFIG_PM_DEVFREQ)
6d743493 CC	221	struct devfreq devfreq_add_device(struct device dev,
	222	struct devfreq_dev_profile *profile,
	223	const char *governor_name,
	224	void *data);
	225	int devfreq_remove_device(struct devfreq *devfreq);
	226	struct devfreq devm_devfreq_add_device(struct device dev,
	227	struct devfreq_dev_profile *profile,
	228	const char *governor_name,
	229	void *data);
	230	void devm_devfreq_remove_device(struct device dev, struct devfreq devfreq);
de9c7394	231
464ed18e	232	/* Supposed to be called by PM callbacks */
6d743493 CC	233	int devfreq_suspend_device(struct devfreq *devfreq);
6d743493 CC	234	int devfreq_resume_device(struct devfreq *devfreq);
a3c98b8b	235
6d743493 CC	236	void devfreq_suspend(void);
6d743493 CC	237	void devfreq_resume(void);
59031956	238
3e2ac979	239	/* update_devfreq() - Reevaluate the device and configure frequency */
6d743493	240	int update_devfreq(struct devfreq *devfreq);
b596d895	241
a3c98b8b	242	/* Helper functions for devfreq user device driver with OPP. */
6d743493 CC	243	struct dev_pm_opp devfreq_recommended_opp(struct device dev,
	244	unsigned long *freq, u32 flags);
	245	int devfreq_register_opp_notifier(struct device *dev,
	246	struct devfreq *devfreq);
	247	int devfreq_unregister_opp_notifier(struct device *dev,
	248	struct devfreq *devfreq);
	249	int devm_devfreq_register_opp_notifier(struct device *dev,
	250	struct devfreq *devfreq);
	251	void devm_devfreq_unregister_opp_notifier(struct device *dev,
	252	struct devfreq *devfreq);
	253	int devfreq_register_notifier(struct devfreq *devfreq,
	254	struct notifier_block *nb,
	255	unsigned int list);
	256	int devfreq_unregister_notifier(struct devfreq *devfreq,
	257	struct notifier_block *nb,
	258	unsigned int list);
	259	int devm_devfreq_register_notifier(struct device *dev,
0fe3a664 CC	260	struct devfreq *devfreq,
	261	struct notifier_block *nb,
	262	unsigned int list);
6d743493	263	void devm_devfreq_unregister_notifier(struct device *dev,
0fe3a664 CC	264	struct devfreq *devfreq,
	265	struct notifier_block *nb,
	266	unsigned int list);
7b38b7b0	267	struct devfreq devfreq_get_devfreq_by_node(struct device_node node);
86d90fd9 CC	268	struct devfreq devfreq_get_devfreq_by_phandle(struct device dev,
86d90fd9 CC	269	const char *phandle_name, int index);
8f510aeb	270
883d588e	271	#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
ce26c5bb	272	/**
7a51320e	273	* struct devfreq_simple_ondemand_data - ``void *data`` fed to struct devfreq
ce26c5bb	274	* and devfreq_add_device
e09651fc	275	* @upthreshold: If the load is over this value, the frequency jumps.
ce26c5bb	276	* Specify 0 to use the default. Valid value = 0 to 100.
e09651fc	277	* @downdifferential: If the load is under upthreshold - downdifferential,
ce26c5bb MH	278	* the governor may consider slowing the frequency down.
	279	* Specify 0 to use the default. Valid value = 0 to 100.
	280	* downdifferential < upthreshold must hold.
	281	*
	282	* If the fed devfreq_simple_ondemand_data pointer is NULL to the governor,
	283	* the governor uses the default values.
	284	*/
	285	struct devfreq_simple_ondemand_data {
	286	unsigned int upthreshold;
	287	unsigned int downdifferential;
	288	};
	289	#endif
	290
99613311	291	#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
a03dacb0 SK	292	enum devfreq_parent_dev_type {
	293	DEVFREQ_PARENT_DEV,
	294	CPUFREQ_PARENT_DEV,
	295	};
	296
99613311	297	/**
7a51320e	298	* struct devfreq_passive_data - ``void *data`` fed to struct devfreq
99613311 CC	299	* and devfreq_add_device
	300	* @parent: the devfreq instance of parent device.
	301	* @get_target_freq: Optional callback, Returns desired operating frequency
	302	* for the device using passive governor. That is called
	303	* when passive governor should decide the next frequency
	304	* by using the new frequency of parent devfreq device
	305	* using governors except for passive governor.
	306	* If the devfreq device has the specific method to decide
	307	* the next frequency, should use this callback.
a03dacb0 SK	308	* @parent_type: the parent type of the device.
	309	* @this: the devfreq instance of own device.
	310	* @nb: the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
	311	* CPUFREQ_TRANSITION_NOTIFIER list.
26984d9d	312	* @cpu_data_list: the list of cpu frequency data for all cpufreq_policy.
99613311 CC	313	*
	314	* The devfreq_passive_data have to set the devfreq instance of parent
	315	* device with governors except for the passive governor. But, don't need to
	316	* initialize the 'this' and 'nb' field because the devfreq core will handle
	317	* them.
	318	*/
	319	struct devfreq_passive_data {
	320	/* Should set the devfreq instance of parent device */
	321	struct devfreq *parent;
	322
	323	/* Optional callback to decide the next frequency of passvice device */
	324	int (get_target_freq)(struct devfreq this, unsigned long *freq);
	325
a03dacb0 SK	326	/* Should set the type of parent device */
	327	enum devfreq_parent_dev_type parent_type;
	328
99613311 CC	329	/* For passive governor's internal use. Don't need to set them */
	330	struct devfreq *this;
	331	struct notifier_block nb;
26984d9d	332	struct list_head cpu_data_list;
99613311 CC	333	};
	334	#endif
	335
a3c98b8b	336	#else /* !CONFIG_PM_DEVFREQ */
5faaa035	337	static inline struct devfreq devfreq_add_device(struct device dev,
6d743493 CC	338	struct devfreq_dev_profile *profile,
	339	const char *governor_name,
	340	void *data)
a3c98b8b	341	{
8cd84092	342	return ERR_PTR(-ENOSYS);
a3c98b8b MH	343	}
a3c98b8b MH	344
5faaa035	345	static inline int devfreq_remove_device(struct devfreq *devfreq)
a3c98b8b MH	346	{
	347	return 0;
	348	}
	349
8cd84092 CC	350	static inline struct devfreq devm_devfreq_add_device(struct device dev,
	351	struct devfreq_dev_profile *profile,
	352	const char *governor_name,
	353	void *data)
	354	{
	355	return ERR_PTR(-ENOSYS);
	356	}
	357
	358	static inline void devm_devfreq_remove_device(struct device *dev,
	359	struct devfreq *devfreq)
	360	{
	361	}
	362
5faaa035	363	static inline int devfreq_suspend_device(struct devfreq *devfreq)
206c30cf RV	364	{
	365	return 0;
	366	}
	367
5faaa035	368	static inline int devfreq_resume_device(struct devfreq *devfreq)
206c30cf RV	369	{
	370	return 0;
	371	}
	372
59031956 LL	373	static inline void devfreq_suspend(void) {}
	374	static inline void devfreq_resume(void) {}
	375
47d43ba7	376	static inline struct dev_pm_opp devfreq_recommended_opp(struct device dev,
6d743493	377	unsigned long *freq, u32 flags)
a3c98b8b	378	{
5faaa035	379	return ERR_PTR(-EINVAL);
a3c98b8b MH	380	}
a3c98b8b MH	381
5faaa035	382	static inline int devfreq_register_opp_notifier(struct device *dev,
6d743493	383	struct devfreq *devfreq)
a3c98b8b MH	384	{
	385	return -EINVAL;
	386	}
	387
5faaa035	388	static inline int devfreq_unregister_opp_notifier(struct device *dev,
6d743493	389	struct devfreq *devfreq)
a3c98b8b MH	390	{
	391	return -EINVAL;
	392	}
	393
d5b040d0	394	static inline int devm_devfreq_register_opp_notifier(struct device *dev,
6d743493	395	struct devfreq *devfreq)
d5b040d0 CC	396	{
	397	return -EINVAL;
	398	}
	399
	400	static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
6d743493	401	struct devfreq *devfreq)
d5b040d0 CC	402	{
d5b040d0 CC	403	}
08e75e75	404
0fe3a664 CC	405	static inline int devfreq_register_notifier(struct devfreq *devfreq,
	406	struct notifier_block *nb,
	407	unsigned int list)
	408	{
	409	return 0;
	410	}
	411
	412	static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
	413	struct notifier_block *nb,
	414	unsigned int list)
	415	{
	416	return 0;
	417	}
	418
	419	static inline int devm_devfreq_register_notifier(struct device *dev,
6d743493 CC	420	struct devfreq *devfreq,
	421	struct notifier_block *nb,
	422	unsigned int list)
0fe3a664 CC	423	{
	424	return 0;
	425	}
	426
	427	static inline void devm_devfreq_unregister_notifier(struct device *dev,
6d743493 CC	428	struct devfreq *devfreq,
	429	struct notifier_block *nb,
	430	unsigned int list)
0fe3a664 CC	431	{
	432	}
	433
7b38b7b0 LC	434	static inline struct devfreq devfreq_get_devfreq_by_node(struct device_node node)
	435	{
	436	return ERR_PTR(-ENODEV);
	437	}
	438
8f510aeb	439	static inline struct devfreq devfreq_get_devfreq_by_phandle(struct device dev,
86d90fd9	440	const char *phandle_name, int index)
8f510aeb CC	441	{
	442	return ERR_PTR(-ENODEV);
	443	}
	444
08e75e75 JM	445	static inline int devfreq_update_stats(struct devfreq *df)
	446	{
	447	return -EINVAL;
	448	}
a3c98b8b MH	449	#endif /* CONFIG_PM_DEVFREQ */
	450
	451	#endif /* __LINUX_DEVFREQ_H__ */