[deliverable/linux.git] / include / linux / cpufreq.h

/*
 *  linux/include/linux/cpufreq.h
 *
 *  Copyright (C) 2001 Russell King
 *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
 *            
 *
 * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
 *
 * 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/config.h>
#include <linux/notifier.h>
#include <linux/threads.h>
#include <linux/device.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/completion.h>
#include <linux/workqueue.h>
#include <linux/cpumask.h>
#include <asm/div64.h>

#define CPUFREQ_NAME_LEN 16


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

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

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


/* 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)

/* Frequency values here are CPU kHz so that hardware which doesn't run 
 * with some frequencies can complain without having to guess what per 
 * cent / per mille means. 
 * Maximum transition latency is in nanoseconds - if it's unknown,
 * CPUFREQ_ETERNAL shall be used.
 */

struct cpufreq_governor;

#define CPUFREQ_ETERNAL			(-1)
struct cpufreq_cpuinfo {
	unsigned int		max_freq;
	unsigned int		min_freq;
	unsigned int		transition_latency; /* in 10^(-9) s = nanoseconds */
};

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 {
	cpumask_t		cpus;	/* affected CPUs */
	unsigned int		cpu;    /* cpu nr of registered CPU */
	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 */

 	struct semaphore	lock;   /* CPU ->setpolicy or ->target may
					   only be called once a time */

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

	struct cpufreq_real_policy	user_policy;

	struct kobject		kobj;
	struct completion	kobj_unregister;
};

#define CPUFREQ_ADJUST		(0)
#define CPUFREQ_INCOMPATIBLE	(1)
#define CPUFREQ_NOTIFY		(2)


/******************** cpufreq transition notifiers *******************/

#define CPUFREQ_PRECHANGE	(0)
#define CPUFREQ_POSTCHANGE	(1)
#define CPUFREQ_RESUMECHANGE	(8)
#define CPUFREQ_SUSPENDCHANGE	(9)

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


/**
 * 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                        *
 *********************************************************************/

#define CPUFREQ_GOV_START  1
#define CPUFREQ_GOV_STOP   2
#define CPUFREQ_GOV_LIMITS 3

struct cpufreq_governor {
	char	name[CPUFREQ_NAME_LEN];
	int 	(*governor)	(struct cpufreq_policy *policy,
				 unsigned int event);
	struct list_head	governor_list;
	struct module		*owner;
};

/* pass a target to the cpufreq driver 
 */
extern int cpufreq_driver_target(struct cpufreq_policy *policy,
				 unsigned int target_freq,
				 unsigned int relation);
extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
				   unsigned int target_freq,
				   unsigned int relation);


/* pass an event to the cpufreq governor */
int cpufreq_governor(unsigned int cpu, unsigned int event);

int cpufreq_register_governor(struct cpufreq_governor *governor);
void cpufreq_unregister_governor(struct cpufreq_governor *governor);


/*********************************************************************
 *                      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 cpufreq_driver {
	struct module           *owner;
	char			name[CPUFREQ_NAME_LEN];
	u8			flags;

	/* 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	(*exit)		(struct cpufreq_policy *policy);
	int	(*suspend)	(struct cpufreq_policy *policy, pm_message_t pmsg);
	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);


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


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;
}

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


/*********************************************************************
 *                        CPUFREQ 2.6. INTERFACE                     *
 *********************************************************************/
int cpufreq_set_policy(struct cpufreq_policy *policy);
int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
int cpufreq_update_policy(unsigned int cpu);

/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
unsigned int cpufreq_get(unsigned int cpu);

/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
#ifdef CONFIG_CPU_FREQ
unsigned int cpufreq_quick_get(unsigned int cpu);
#else
static inline unsigned int cpufreq_quick_get(unsigned int cpu)
{
	return 0;
}
#endif


/*********************************************************************
 *                       CPUFREQ DEFAULT GOVERNOR                    *
 *********************************************************************/


#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
extern struct cpufreq_governor cpufreq_gov_performance;
#define CPUFREQ_DEFAULT_GOVERNOR	&cpufreq_gov_performance
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
extern struct cpufreq_governor cpufreq_gov_userspace;
#define CPUFREQ_DEFAULT_GOVERNOR	&cpufreq_gov_userspace
#endif


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

#define CPUFREQ_ENTRY_INVALID ~0
#define CPUFREQ_TABLE_END     ~1

struct cpufreq_frequency_table {
	unsigned int	index;     /* any */
	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);

/* the following 3 funtions are for cpufreq core use only */
struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
void   cpufreq_cpu_put (struct cpufreq_policy *data);

/* 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);


/*********************************************************************
 *                     UNIFIED DEBUG HELPERS                         *
 *********************************************************************/

#define CPUFREQ_DEBUG_CORE	1
#define CPUFREQ_DEBUG_DRIVER	2
#define CPUFREQ_DEBUG_GOVERNOR	4

#ifdef CONFIG_CPU_FREQ_DEBUG

extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 
				 const char *fmt, ...);

#else

#define cpufreq_debug_printk(msg...) do { } while(0)

#endif /* CONFIG_CPU_FREQ_DEBUG */

#endif /* _LINUX_CPUFREQ_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/include/linux/cpufreq.h
	3	*
	4	* Copyright (C) 2001 Russell King
	5	* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
	6	*
	7	*
	8	* $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14	#ifndef _LINUX_CPUFREQ_H
	15	#define _LINUX_CPUFREQ_H
	16
	17	#include <linux/config.h>
	18	#include <linux/notifier.h>
	19	#include <linux/threads.h>
	20	#include <linux/device.h>
	21	#include <linux/kobject.h>
	22	#include <linux/sysfs.h>
	23	#include <linux/completion.h>
	24	#include <linux/workqueue.h>
	25	#include <linux/cpumask.h>
4e57b681	26	#include <asm/div64.h>
1da177e4 LT	27
	28	#define CPUFREQ_NAME_LEN 16
	29
	30
	31	/*********************************************************************
	32	* CPUFREQ NOTIFIER INTERFACE *
	33	*********************************************************************/
	34
	35	int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
	36	int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
	37
	38	#define CPUFREQ_TRANSITION_NOTIFIER (0)
	39	#define CPUFREQ_POLICY_NOTIFIER (1)
	40
	41
	42	/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
	43	* within the limits is used. If (cpufreq_driver->setpolicy> exists, these
	44	* two generic policies are available:
	45	*/
	46
	47	#define CPUFREQ_POLICY_POWERSAVE (1)
	48	#define CPUFREQ_POLICY_PERFORMANCE (2)
	49
	50	/* Frequency values here are CPU kHz so that hardware which doesn't run
	51	* with some frequencies can complain without having to guess what per
	52	* cent / per mille means.
b53cc6ea	53	* Maximum transition latency is in nanoseconds - if it's unknown,
1da177e4 LT	54	* CPUFREQ_ETERNAL shall be used.
	55	*/
	56
	57	struct cpufreq_governor;
	58
	59	#define CPUFREQ_ETERNAL (-1)
	60	struct cpufreq_cpuinfo {
	61	unsigned int max_freq;
	62	unsigned int min_freq;
	63	unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
	64	};
	65
	66	struct cpufreq_real_policy {
	67	unsigned int min; /* in kHz */
	68	unsigned int max; /* in kHz */
	69	unsigned int policy; /* see above */
	70	struct cpufreq_governor governor; / see below */
	71	};
	72
	73	struct cpufreq_policy {
	74	cpumask_t cpus; /* affected CPUs */
	75	unsigned int cpu; /* cpu nr of registered CPU */
	76	struct cpufreq_cpuinfo cpuinfo;/* see above */
	77
	78	unsigned int min; /* in kHz */
	79	unsigned int max; /* in kHz */
	80	unsigned int cur; /* in kHz, only needed if cpufreq
	81	* governors are used */
	82	unsigned int policy; /* see above */
	83	struct cpufreq_governor governor; / see below */
	84
	85	struct semaphore lock; /* CPU ->setpolicy or ->target may
	86	only be called once a time */
	87
	88	struct work_struct update; /* if update_policy() needs to be
	89	* called, but you're in IRQ context */
	90
	91	struct cpufreq_real_policy user_policy;
	92
	93	struct kobject kobj;
	94	struct completion kobj_unregister;
	95	};
	96
	97	#define CPUFREQ_ADJUST (0)
	98	#define CPUFREQ_INCOMPATIBLE (1)
	99	#define CPUFREQ_NOTIFY (2)
	100
	101
	102	/****************** cpufreq transition notifiers *****************/
	103
	104	#define CPUFREQ_PRECHANGE (0)
	105	#define CPUFREQ_POSTCHANGE (1)
	106	#define CPUFREQ_RESUMECHANGE (8)
42d4dc3f	107	#define CPUFREQ_SUSPENDCHANGE (9)
1da177e4 LT	108
	109	struct cpufreq_freqs {
	110	unsigned int cpu; /* cpu nr */
	111	unsigned int old;
	112	unsigned int new;
	113	u8 flags; /* flags of cpufreq_driver, see below. */
	114	};
	115
	116
	117	/**
	118	* cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
	119	* @old: old value
	120	* @div: divisor
	121	* @mult: multiplier
	122	*
	123	*
	124	* new = old * mult / div
	125	*/
	126	static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
	127	{
	128	#if BITS_PER_LONG == 32
	129
	130	u64 result = ((u64) old) * ((u64) mult);
	131	do_div(result, div);
	132	return (unsigned long) result;
	133
	134	#elif BITS_PER_LONG == 64
	135
	136	unsigned long result = old * ((u64) mult);
	137	result /= div;
	138	return result;
	139
	140	#endif
	141	};
	142
	143	/*********************************************************************
	144	* CPUFREQ GOVERNORS *
	145	*********************************************************************/
	146
	147	#define CPUFREQ_GOV_START 1
	148	#define CPUFREQ_GOV_STOP 2
	149	#define CPUFREQ_GOV_LIMITS 3
	150
	151	struct cpufreq_governor {
	152	char name[CPUFREQ_NAME_LEN];
	153	int (governor) (struct cpufreq_policy policy,
	154	unsigned int event);
	155	struct list_head governor_list;
	156	struct module *owner;
	157	};
	158
	159	/* pass a target to the cpufreq driver
	160	*/
	161	extern int cpufreq_driver_target(struct cpufreq_policy *policy,
	162	unsigned int target_freq,
	163	unsigned int relation);
	164	extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
	165	unsigned int target_freq,
	166	unsigned int relation);
	167
	168
	169	/* pass an event to the cpufreq governor */
	170	int cpufreq_governor(unsigned int cpu, unsigned int event);
	171
172	int cpufreq_register_governor(struct cpufreq_governor *governor);
173	void cpufreq_unregister_governor(struct cpufreq_governor *governor);
174
175
176	/*********************************************************************
177	* CPUFREQ DRIVER INTERFACE *
178	*********************************************************************/
179
180	#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
181	#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
182
183	struct freq_attr;
184
185	struct cpufreq_driver {
186	struct module *owner;
187	char name[CPUFREQ_NAME_LEN];
188	u8 flags;
189
190	/* needed by all drivers */
191	int (init) (struct cpufreq_policy policy);
192	int (verify) (struct cpufreq_policy policy);
193
194	/* define one out of two */
195	int (setpolicy) (struct cpufreq_policy policy);
196	int (target) (struct cpufreq_policy policy,
197	unsigned int target_freq,
198	unsigned int relation);
199
200	/* should be defined, if possible */
201	unsigned int (*get) (unsigned int cpu);
202
203	/* optional */
204	int (exit) (struct cpufreq_policy policy);
e00d9967	205	int (suspend) (struct cpufreq_policy policy, pm_message_t pmsg);
1da177e4 LT	206	int (resume) (struct cpufreq_policy policy);
	207	struct freq_attr **attr;
	208	};
	209
	210	/* flags */
	211
	212	#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
	213	* all ->init() calls failed */
	214	#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
	215	* "constants" aren't affected by
	216	* frequency transitions */
42d4dc3f BH	217	#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
42d4dc3f BH	218	* mismatches */
1da177e4 LT	219
	220	int cpufreq_register_driver(struct cpufreq_driver *driver_data);
	221	int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
	222
	223
	224	void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
	225
	226
	227	static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
	228	{
	229	if (policy->min < min)
	230	policy->min = min;
	231	if (policy->max < min)
	232	policy->max = min;
	233	if (policy->min > max)
	234	policy->min = max;
	235	if (policy->max > max)
	236	policy->max = max;
	237	if (policy->min > policy->max)
	238	policy->min = policy->max;
	239	return;
	240	}
	241
	242	struct freq_attr {
	243	struct attribute attr;
	244	ssize_t (show)(struct cpufreq_policy , char *);
	245	ssize_t (store)(struct cpufreq_policy , const char *, size_t count);
	246	};
	247
	248
	249	/*********************************************************************
	250	* CPUFREQ 2.6. INTERFACE *
	251	*********************************************************************/
	252	int cpufreq_set_policy(struct cpufreq_policy *policy);
	253	int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
	254	int cpufreq_update_policy(unsigned int cpu);
	255
	256	/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
	257	unsigned int cpufreq_get(unsigned int cpu);
	258
95235ca2 VP	259	/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
	260	#ifdef CONFIG_CPU_FREQ
	261	unsigned int cpufreq_quick_get(unsigned int cpu);
	262	#else
	263	static inline unsigned int cpufreq_quick_get(unsigned int cpu)
	264	{
	265	return 0;
	266	}
	267	#endif
	268
1da177e4 LT	269
	270	/*********************************************************************
	271	* CPUFREQ DEFAULT GOVERNOR *
	272	*********************************************************************/
	273
	274
	275	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
	276	extern struct cpufreq_governor cpufreq_gov_performance;
	277	#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
	278	#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
	279	extern struct cpufreq_governor cpufreq_gov_userspace;
	280	#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
	281	#endif
	282
	283
	284	/*********************************************************************
	285	* FREQUENCY TABLE HELPERS *
	286	*********************************************************************/
	287
	288	#define CPUFREQ_ENTRY_INVALID ~0
	289	#define CPUFREQ_TABLE_END ~1
	290
	291	struct cpufreq_frequency_table {
	292	unsigned int index; /* any */
	293	unsigned int frequency; /* kHz - doesn't need to be in ascending
	294	* order */
	295	};
	296
	297	int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
	298	struct cpufreq_frequency_table *table);
	299
	300	int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
	301	struct cpufreq_frequency_table *table);
	302
	303	int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
	304	struct cpufreq_frequency_table *table,
	305	unsigned int target_freq,
	306	unsigned int relation,
	307	unsigned int *index);
	308
	309	/* the following 3 funtions are for cpufreq core use only */
	310	struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
	311	struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
	312	void cpufreq_cpu_put (struct cpufreq_policy *data);
	313
	314	/* the following are really really optional */
	315	extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
	316
	317	void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
	318	unsigned int cpu);
	319
	320	void cpufreq_frequency_table_put_attr(unsigned int cpu);
	321
	322
	323	/*********************************************************************
	324	* UNIFIED DEBUG HELPERS *
	325	*********************************************************************/
	326
	327	#define CPUFREQ_DEBUG_CORE 1
	328	#define CPUFREQ_DEBUG_DRIVER 2
	329	#define CPUFREQ_DEBUG_GOVERNOR 4
	330
	331	#ifdef CONFIG_CPU_FREQ_DEBUG
	332
333	extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
334	const char *fmt, ...);
335
336	#else
337
338	#define cpufreq_debug_printk(msg...) do { } while(0)
339
340	#endif /* CONFIG_CPU_FREQ_DEBUG */
341
342	#endif /* _LINUX_CPUFREQ_H */