include/linux/cpufreq.h - kernel/msm-4.9 - Gitiles

 /*
  * linux/include/linux/cpufreq.h
  *
  * Copyright (C) 2001 Russell King
  *           (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
  *
  * 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 _LINUX_CPUFREQ_H
 #define _LINUX_CPUFREQ_H

 #include <linux/cpumask.h>
 #include <linux/completion.h>
 #include <linux/kobject.h>
 #include <linux/notifier.h>
 #include <linux/sysfs.h>

 /*********************************************************************
  *                        CPUFREQ INTERFACE                          *
  *********************************************************************/
 /*
  * Frequency values here are CPU kHz
  *
  * Maximum transition latency is in nanoseconds - if it's unknown,
  * CPUFREQ_ETERNAL shall be used.
  */

 #define CPUFREQ_ETERNAL			(-1)
 #define CPUFREQ_NAME_LEN		16
 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
 #define CPUFREQ_NAME_PLEN		(CPUFREQ_NAME_LEN + 1)

 struct cpufreq_governor;

 struct cpufreq_freqs {
 	unsigned int cpu;	/* cpu nr */
 	unsigned int old;
 	unsigned int new;
 	u8 flags;		/* flags of cpufreq_driver, see below. */
 };

 struct cpufreq_cpuinfo {
 	unsigned int		max_freq;
 	unsigned int		min_freq;

 	/* in 10^(-9) s = nanoseconds */
 	unsigned int		transition_latency;
 };

 struct cpufreq_real_policy {
 	unsigned int		min;    /* in kHz */
 	unsigned int		max;    /* in kHz */
 	unsigned int		policy; /* see above */
 	struct cpufreq_governor	*governor; /* see below */
 };

 struct cpufreq_policy {
 	/* CPUs sharing clock, require sw coordination */
 	cpumask_var_t		cpus;	/* Online CPUs only */
 	cpumask_var_t		related_cpus; /* Online + Offline CPUs */

 	unsigned int		shared_type; /* ACPI: ANY or ALL affected CPUs
 						should set cpufreq */
 	unsigned int		cpu;    /* cpu nr of CPU managing this policy */
 	unsigned int		last_cpu; /* cpu nr of previous CPU that managed
 					   * this policy */
 	struct cpufreq_cpuinfo	cpuinfo;/* see above */

 	unsigned int		min;    /* in kHz */
 	unsigned int		max;    /* in kHz */
 	unsigned int		cur;    /* in kHz, only needed if cpufreq
 					 * governors are used */
 	unsigned int		policy; /* see above */
 	struct cpufreq_governor	*governor; /* see below */
 	void			*governor_data;
 	bool			governor_enabled; /* governor start/stop flag */

 	struct work_struct	update; /* if update_policy() needs to be
 					 * called, but you're in IRQ context */

 	struct cpufreq_real_policy	user_policy;

 	struct list_head        policy_list;
 	struct kobject		kobj;
 	struct completion	kobj_unregister;
 };

 /* Only for ACPI */
 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
 #define CPUFREQ_SHARED_TYPE_HW	 (1) /* HW does needed coordination */
 #define CPUFREQ_SHARED_TYPE_ALL	 (2) /* All dependent CPUs should set freq */
 #define CPUFREQ_SHARED_TYPE_ANY	 (3) /* Freq can be set from any dependent CPU*/

 #ifdef CONFIG_CPU_FREQ
 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
 void cpufreq_cpu_put(struct cpufreq_policy *policy);
 #else
 static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
 {
 	return NULL;
 }
 static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
 #endif

 static inline bool policy_is_shared(struct cpufreq_policy *policy)
 {
 	return cpumask_weight(policy->cpus) > 1;
 }

 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
 extern struct kobject *cpufreq_global_kobject;
 int cpufreq_get_global_kobject(void);
 void cpufreq_put_global_kobject(void);
 int cpufreq_sysfs_create_file(const struct attribute *attr);
 void cpufreq_sysfs_remove_file(const struct attribute *attr);

 #ifdef CONFIG_CPU_FREQ
 unsigned int cpufreq_get(unsigned int cpu);
 unsigned int cpufreq_quick_get(unsigned int cpu);
 unsigned int cpufreq_quick_get_max(unsigned int cpu);
 void disable_cpufreq(void);

 u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
 int cpufreq_update_policy(unsigned int cpu);
 bool have_governor_per_policy(void);
 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
 #else
 static inline unsigned int cpufreq_get(unsigned int cpu)
 {
 	return 0;
 }
 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
 {
 	return 0;
 }
 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
 {
 	return 0;
 }
 static inline void disable_cpufreq(void) { }
 #endif

 /*********************************************************************
  *                      CPUFREQ DRIVER INTERFACE                     *
  *********************************************************************/

 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */

 struct freq_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct cpufreq_policy *, char *);
 	ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
 };

 #define cpufreq_freq_attr_ro(_name)		\
 static struct freq_attr _name =			\
 __ATTR(_name, 0444, show_##_name, NULL)

 #define cpufreq_freq_attr_ro_perm(_name, _perm)	\
 static struct freq_attr _name =			\
 __ATTR(_name, _perm, show_##_name, NULL)

 #define cpufreq_freq_attr_rw(_name)		\
 static struct freq_attr _name =			\
 __ATTR(_name, 0644, show_##_name, store_##_name)

 struct global_attr {
 	struct attribute attr;
 	ssize_t (*show)(struct kobject *kobj,
 			struct attribute *attr, char *buf);
 	ssize_t (*store)(struct kobject *a, struct attribute *b,
 			 const char *c, size_t count);
 };

 #define define_one_global_ro(_name)		\
 static struct global_attr _name =		\
 __ATTR(_name, 0444, show_##_name, NULL)

 #define define_one_global_rw(_name)		\
 static struct global_attr _name =		\
 __ATTR(_name, 0644, show_##_name, store_##_name)


 struct cpufreq_driver {
 	char			name[CPUFREQ_NAME_LEN];
 	u8			flags;
 	/*
 	 * This should be set by platforms having multiple clock-domains, i.e.
 	 * supporting multiple policies. With this sysfs directories of governor
 	 * would be created in cpu/cpu<num>/cpufreq/ directory and so they can
 	 * use the same governor with different tunables for different clusters.
 	 */
 	bool			have_governor_per_policy;

 	/* needed by all drivers */
 	int	(*init)		(struct cpufreq_policy *policy);
 	int	(*verify)	(struct cpufreq_policy *policy);

 	/* define one out of two */
 	int	(*setpolicy)	(struct cpufreq_policy *policy);
 	int	(*target)	(struct cpufreq_policy *policy,
 				 unsigned int target_freq,
 				 unsigned int relation);

 	/* should be defined, if possible */
 	unsigned int	(*get)	(unsigned int cpu);

 	/* optional */
 	int	(*bios_limit)	(int cpu, unsigned int *limit);

 	int	(*exit)		(struct cpufreq_policy *policy);
 	int	(*suspend)	(struct cpufreq_policy *policy);
 	int	(*resume)	(struct cpufreq_policy *policy);
 	struct freq_attr	**attr;
 };

 /* flags */
 #define CPUFREQ_STICKY		0x01	/* the driver isn't removed even if
 					 * all ->init() calls failed */
 #define CPUFREQ_CONST_LOOPS	0x02	/* loops_per_jiffy or other kernel
 					 * "constants" aren't affected by
 					 * frequency transitions */
 #define CPUFREQ_PM_NO_WARN	0x04	/* don't warn on suspend/resume speed
 					 * mismatches */

 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);

 const char *cpufreq_get_current_driver(void);

 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
 		unsigned int min, unsigned int max)
 {
 	if (policy->min < min)
 		policy->min = min;
 	if (policy->max < min)
 		policy->max = min;
 	if (policy->min > max)
 		policy->min = max;
 	if (policy->max > max)
 		policy->max = max;
 	if (policy->min > policy->max)
 		policy->min = policy->max;
 	return;
 }

 /*********************************************************************
  *                     CPUFREQ NOTIFIER INTERFACE                    *
  *********************************************************************/

 #define CPUFREQ_TRANSITION_NOTIFIER	(0)
 #define CPUFREQ_POLICY_NOTIFIER		(1)

 /* Transition notifiers */
 #define CPUFREQ_PRECHANGE		(0)
 #define CPUFREQ_POSTCHANGE		(1)
 #define CPUFREQ_RESUMECHANGE		(8)
 #define CPUFREQ_SUSPENDCHANGE		(9)

 /* Policy Notifiers  */
 #define CPUFREQ_ADJUST			(0)
 #define CPUFREQ_INCOMPATIBLE		(1)
 #define CPUFREQ_NOTIFY			(2)
 #define CPUFREQ_START			(3)
 #define CPUFREQ_UPDATE_POLICY_CPU	(4)

 #ifdef CONFIG_CPU_FREQ
 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);

 void cpufreq_notify_transition(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs, unsigned int state);

 #else /* CONFIG_CPU_FREQ */
 static inline int cpufreq_register_notifier(struct notifier_block *nb,
 						unsigned int list)
 {
 	return 0;
 }
 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
 						unsigned int list)
 {
 	return 0;
 }
 #endif /* !CONFIG_CPU_FREQ */

 /**
  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
  * safe)
  * @old:   old value
  * @div:   divisor
  * @mult:  multiplier
  *
  *
  * new = old * mult / div
  */
 static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
 		u_int mult)
 {
 #if BITS_PER_LONG == 32
 	u64 result = ((u64) old) * ((u64) mult);
 	do_div(result, div);
 	return (unsigned long) result;

 #elif BITS_PER_LONG == 64
 	unsigned long result = old * ((u64) mult);
 	result /= div;
 	return result;
 #endif
 }

 /*********************************************************************
  *                          CPUFREQ GOVERNORS                        *
  *********************************************************************/

 /*
  * If (cpufreq_driver->target) exists, the ->governor decides what frequency
  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
  * two generic policies are available:
  */
 #define CPUFREQ_POLICY_POWERSAVE	(1)
 #define CPUFREQ_POLICY_PERFORMANCE	(2)

 /* Governor Events */
 #define CPUFREQ_GOV_START	1
 #define CPUFREQ_GOV_STOP	2
 #define CPUFREQ_GOV_LIMITS	3
 #define CPUFREQ_GOV_POLICY_INIT	4
 #define CPUFREQ_GOV_POLICY_EXIT	5

 struct cpufreq_governor {
 	char	name[CPUFREQ_NAME_LEN];
 	int	initialized;
 	int	(*governor)	(struct cpufreq_policy *policy,
 				 unsigned int event);
 	ssize_t	(*show_setspeed)	(struct cpufreq_policy *policy,
 					 char *buf);
 	int	(*store_setspeed)	(struct cpufreq_policy *policy,
 					 unsigned int freq);
 	unsigned int max_transition_latency; /* HW must be able to switch to
 			next freq faster than this value in nano secs or we
 			will fallback to performance governor */
 	struct list_head	governor_list;
 	struct module		*owner;
 };

 /* Pass a target to the cpufreq driver */
 int cpufreq_driver_target(struct cpufreq_policy *policy,
 				 unsigned int target_freq,
 				 unsigned int relation);
 int __cpufreq_driver_target(struct cpufreq_policy *policy,
 				   unsigned int target_freq,
 				   unsigned int relation);
 int cpufreq_register_governor(struct cpufreq_governor *governor);
 void cpufreq_unregister_governor(struct cpufreq_governor *governor);

 /* CPUFREQ DEFAULT GOVERNOR */
 /*
  * Performance governor is fallback governor if any other gov failed to auto
  * load due latency restrictions
  */
 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
 extern struct cpufreq_governor cpufreq_gov_performance;
 #endif
 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_performance)
 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
 extern struct cpufreq_governor cpufreq_gov_powersave;
 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_powersave)
 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 extern struct cpufreq_governor cpufreq_gov_userspace;
 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_userspace)
 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
 extern struct cpufreq_governor cpufreq_gov_ondemand;
 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_ondemand)
 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
 extern struct cpufreq_governor cpufreq_gov_conservative;
 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_conservative)
 #endif

 /*********************************************************************
  *                     FREQUENCY TABLE HELPERS                       *
  *********************************************************************/

 #define CPUFREQ_ENTRY_INVALID ~0
 #define CPUFREQ_TABLE_END     ~1

 struct cpufreq_frequency_table {
 	unsigned int	driver_data; /* driver specific data, not used by core */
 	unsigned int	frequency; /* kHz - doesn't need to be in ascending
 				    * order */
 };

 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
 				    struct cpufreq_frequency_table *table);

 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
 				   struct cpufreq_frequency_table *table);

 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
 				   struct cpufreq_frequency_table *table,
 				   unsigned int target_freq,
 				   unsigned int relation,
 				   unsigned int *index);

 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
 ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);

 /* the following funtion is for cpufreq core use only */
 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);

 /* the following are really really optional */
 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
 				      unsigned int cpu);
 void cpufreq_frequency_table_put_attr(unsigned int cpu);

 #endif /* _LINUX_CPUFREQ_H */
	/*
	* linux/include/linux/cpufreq.h
	*
	* Copyright (C) 2001 Russell King
	* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
	*
	* 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 _LINUX_CPUFREQ_H
	#define _LINUX_CPUFREQ_H

	#include <linux/cpumask.h>
	#include <linux/completion.h>
	#include <linux/kobject.h>
	#include <linux/notifier.h>
	#include <linux/sysfs.h>

	/*********************************************************************
	* CPUFREQ INTERFACE *
	*********************************************************************/
	/*
	* Frequency values here are CPU kHz
	*
	* Maximum transition latency is in nanoseconds - if it's unknown,
	* CPUFREQ_ETERNAL shall be used.
	*/

	#define CPUFREQ_ETERNAL (-1)
	#define CPUFREQ_NAME_LEN 16
	/* Print length for names. Extra 1 space for accomodating '\n' in prints */
	#define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)

	struct cpufreq_governor;

	struct cpufreq_freqs {
	unsigned int cpu; /* cpu nr */
	unsigned int old;
	unsigned int new;
	u8 flags; /* flags of cpufreq_driver, see below. */
	};

	struct cpufreq_cpuinfo {
	unsigned int max_freq;
	unsigned int min_freq;

	/* in 10^(-9) s = nanoseconds */
	unsigned int transition_latency;
	};

	struct cpufreq_real_policy {
	unsigned int min; /* in kHz */
	unsigned int max; /* in kHz */
	unsigned int policy; /* see above */
	struct cpufreq_governor governor; / see below */
	};

	struct cpufreq_policy {
	/* CPUs sharing clock, require sw coordination */
	cpumask_var_t cpus; /* Online CPUs only */
	cpumask_var_t related_cpus; /* Online + Offline CPUs */

	unsigned int shared_type; /* ACPI: ANY or ALL affected CPUs
	should set cpufreq */
	unsigned int cpu; /* cpu nr of CPU managing this policy */
	unsigned int last_cpu; /* cpu nr of previous CPU that managed
	* this policy */
	struct cpufreq_cpuinfo cpuinfo;/* see above */

	unsigned int min; /* in kHz */
	unsigned int max; /* in kHz */
	unsigned int cur; /* in kHz, only needed if cpufreq
	* governors are used */
	unsigned int policy; /* see above */
	struct cpufreq_governor governor; / see below */
	void *governor_data;
	bool governor_enabled; /* governor start/stop flag */

	struct work_struct update; /* if update_policy() needs to be
	* called, but you're in IRQ context */

	struct cpufreq_real_policy user_policy;

	struct list_head policy_list;
	struct kobject kobj;
	struct completion kobj_unregister;
	};

	/* Only for ACPI */
	#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
	#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
	#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
	#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/

	#ifdef CONFIG_CPU_FREQ
	struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
	void cpufreq_cpu_put(struct cpufreq_policy *policy);
	#else
	static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
	{
	return NULL;
	}
	static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
	#endif

	static inline bool policy_is_shared(struct cpufreq_policy *policy)
	{
	return cpumask_weight(policy->cpus) > 1;
	}

	/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
	extern struct kobject *cpufreq_global_kobject;
	int cpufreq_get_global_kobject(void);
	void cpufreq_put_global_kobject(void);
	int cpufreq_sysfs_create_file(const struct attribute *attr);
	void cpufreq_sysfs_remove_file(const struct attribute *attr);

	#ifdef CONFIG_CPU_FREQ
	unsigned int cpufreq_get(unsigned int cpu);
	unsigned int cpufreq_quick_get(unsigned int cpu);
	unsigned int cpufreq_quick_get_max(unsigned int cpu);
	void disable_cpufreq(void);

	u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
	int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
	int cpufreq_update_policy(unsigned int cpu);
	bool have_governor_per_policy(void);
	struct kobject get_governor_parent_kobj(struct cpufreq_policy policy);
	#else
	static inline unsigned int cpufreq_get(unsigned int cpu)
	{
	return 0;
	}
	static inline unsigned int cpufreq_quick_get(unsigned int cpu)
	{
	return 0;
	}
	static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
	{
	return 0;
	}
	static inline void disable_cpufreq(void) { }
	#endif

	/*********************************************************************
	* CPUFREQ DRIVER INTERFACE *
	*********************************************************************/

	#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
	#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */

	struct freq_attr {
	struct attribute attr;
	ssize_t (show)(struct cpufreq_policy , char *);
	ssize_t (store)(struct cpufreq_policy , const char *, size_t count);
	};

	#define cpufreq_freq_attr_ro(_name) \
	static struct freq_attr _name = \
	__ATTR(_name, 0444, show_##_name, NULL)

	#define cpufreq_freq_attr_ro_perm(_name, _perm) \
	static struct freq_attr _name = \
	__ATTR(_name, _perm, show_##_name, NULL)

	#define cpufreq_freq_attr_rw(_name) \
	static struct freq_attr _name = \
	__ATTR(_name, 0644, show_##_name, store_##_name)

	struct global_attr {
	struct attribute attr;
	ssize_t (show)(struct kobject kobj,
	struct attribute attr, char buf);
	ssize_t (store)(struct kobject a, struct attribute *b,
	const char *c, size_t count);
	};

	#define define_one_global_ro(_name) \
	static struct global_attr _name = \
	__ATTR(_name, 0444, show_##_name, NULL)

	#define define_one_global_rw(_name) \
	static struct global_attr _name = \
	__ATTR(_name, 0644, show_##_name, store_##_name)


	struct cpufreq_driver {
	char name[CPUFREQ_NAME_LEN];
	u8 flags;
	/*
	* This should be set by platforms having multiple clock-domains, i.e.
	* supporting multiple policies. With this sysfs directories of governor
	* would be created in cpu/cpu<num>/cpufreq/ directory and so they can
	* use the same governor with different tunables for different clusters.
	*/
	bool have_governor_per_policy;

	/* needed by all drivers */
	int (init) (struct cpufreq_policy policy);
	int (verify) (struct cpufreq_policy policy);

	/* define one out of two */
	int (setpolicy) (struct cpufreq_policy policy);
	int (target) (struct cpufreq_policy policy,
	unsigned int target_freq,
	unsigned int relation);

	/* should be defined, if possible */
	unsigned int (*get) (unsigned int cpu);

	/* optional */
	int (bios_limit) (int cpu, unsigned int limit);

	int (exit) (struct cpufreq_policy policy);
	int (suspend) (struct cpufreq_policy policy);
	int (resume) (struct cpufreq_policy policy);
	struct freq_attr **attr;
	};

	/* flags */
	#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
	* all ->init() calls failed */
	#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
	* "constants" aren't affected by
	* frequency transitions */
	#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
	* mismatches */

	int cpufreq_register_driver(struct cpufreq_driver *driver_data);
	int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);

	const char *cpufreq_get_current_driver(void);

	static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy,
	unsigned int min, unsigned int max)
	{
	if (policy->min < min)
	policy->min = min;
	if (policy->max < min)
	policy->max = min;
	if (policy->min > max)
	policy->min = max;
	if (policy->max > max)
	policy->max = max;
	if (policy->min > policy->max)
	policy->min = policy->max;
	return;
	}

	/*********************************************************************
	* CPUFREQ NOTIFIER INTERFACE *
	*********************************************************************/

	#define CPUFREQ_TRANSITION_NOTIFIER (0)
	#define CPUFREQ_POLICY_NOTIFIER (1)

	/* Transition notifiers */
	#define CPUFREQ_PRECHANGE (0)
	#define CPUFREQ_POSTCHANGE (1)
	#define CPUFREQ_RESUMECHANGE (8)
	#define CPUFREQ_SUSPENDCHANGE (9)

	/* Policy Notifiers */
	#define CPUFREQ_ADJUST (0)
	#define CPUFREQ_INCOMPATIBLE (1)
	#define CPUFREQ_NOTIFY (2)
	#define CPUFREQ_START (3)
	#define CPUFREQ_UPDATE_POLICY_CPU (4)

	#ifdef CONFIG_CPU_FREQ
	int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
	int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);

	void cpufreq_notify_transition(struct cpufreq_policy *policy,
	struct cpufreq_freqs *freqs, unsigned int state);

	#else /* CONFIG_CPU_FREQ */
	static inline int cpufreq_register_notifier(struct notifier_block *nb,
	unsigned int list)
	{
	return 0;
	}
	static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
	unsigned int list)
	{
	return 0;
	}
	#endif /* !CONFIG_CPU_FREQ */

	/**
	* cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
	* safe)
	* @old: old value
	* @div: divisor
	* @mult: multiplier
	*
	*
	* new = old * mult / div
	*/
	static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
	u_int mult)
	{
	#if BITS_PER_LONG == 32
	u64 result = ((u64) old) * ((u64) mult);
	do_div(result, div);
	return (unsigned long) result;

	#elif BITS_PER_LONG == 64
	unsigned long result = old * ((u64) mult);
	result /= div;
	return result;
	#endif
	}

	/*********************************************************************
	* CPUFREQ GOVERNORS *
	*********************************************************************/

	/*
	* If (cpufreq_driver->target) exists, the ->governor decides what frequency
	* within the limits is used. If (cpufreq_driver->setpolicy> exists, these
	* two generic policies are available:
	*/
	#define CPUFREQ_POLICY_POWERSAVE (1)
	#define CPUFREQ_POLICY_PERFORMANCE (2)

	/* Governor Events */
	#define CPUFREQ_GOV_START 1
	#define CPUFREQ_GOV_STOP 2
	#define CPUFREQ_GOV_LIMITS 3
	#define CPUFREQ_GOV_POLICY_INIT 4
	#define CPUFREQ_GOV_POLICY_EXIT 5

	struct cpufreq_governor {
	char name[CPUFREQ_NAME_LEN];
	int initialized;
	int (governor) (struct cpufreq_policy policy,
	unsigned int event);
	ssize_t (show_setspeed) (struct cpufreq_policy policy,
	char *buf);
	int (store_setspeed) (struct cpufreq_policy policy,
	unsigned int freq);
	unsigned int max_transition_latency; /* HW must be able to switch to
	next freq faster than this value in nano secs or we
	will fallback to performance governor */
	struct list_head governor_list;
	struct module *owner;
	};

	/* Pass a target to the cpufreq driver */
	int cpufreq_driver_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation);
	int __cpufreq_driver_target(struct cpufreq_policy *policy,
	unsigned int target_freq,
	unsigned int relation);
	int cpufreq_register_governor(struct cpufreq_governor *governor);
	void cpufreq_unregister_governor(struct cpufreq_governor *governor);

	/* CPUFREQ DEFAULT GOVERNOR */
	/*
	* Performance governor is fallback governor if any other gov failed to auto
	* load due latency restrictions
	*/
	#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
	extern struct cpufreq_governor cpufreq_gov_performance;
	#endif
	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
	#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
	#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
	extern struct cpufreq_governor cpufreq_gov_powersave;
	#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
	#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
	extern struct cpufreq_governor cpufreq_gov_userspace;
	#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
	#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
	extern struct cpufreq_governor cpufreq_gov_ondemand;
	#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
	#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
	extern struct cpufreq_governor cpufreq_gov_conservative;
	#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
	#endif

	/*********************************************************************
	* FREQUENCY TABLE HELPERS *
	*********************************************************************/

	#define CPUFREQ_ENTRY_INVALID ~0
	#define CPUFREQ_TABLE_END ~1

	struct cpufreq_frequency_table {
	unsigned int driver_data; /* driver specific data, not used by core */
	unsigned int frequency; /* kHz - doesn't need to be in ascending
	* order */
	};

	int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
	struct cpufreq_frequency_table *table);

	int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
	struct cpufreq_frequency_table *table);

	int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
	struct cpufreq_frequency_table *table,
	unsigned int target_freq,
	unsigned int relation,
	unsigned int *index);

	void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
	ssize_t cpufreq_show_cpus(const struct cpumask mask, char buf);

	/* the following funtion is for cpufreq core use only */
	struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);

	/* the following are really really optional */
	extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
	void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
	unsigned int cpu);
	void cpufreq_frequency_table_put_attr(unsigned int cpu);

	#endif /* _LINUX_CPUFREQ_H */