[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/mutex.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 mutex		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
83933af4	17	#include <linux/mutex.h>
1da177e4 LT	18	#include <linux/config.h>
	19	#include <linux/notifier.h>
	20	#include <linux/threads.h>
	21	#include <linux/device.h>
	22	#include <linux/kobject.h>
	23	#include <linux/sysfs.h>
	24	#include <linux/completion.h>
	25	#include <linux/workqueue.h>
	26	#include <linux/cpumask.h>
4e57b681	27	#include <asm/div64.h>
1da177e4 LT	28
	29	#define CPUFREQ_NAME_LEN 16
	30
	31
	32	/*********************************************************************
	33	* CPUFREQ NOTIFIER INTERFACE *
	34	*********************************************************************/
	35
	36	int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
	37	int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
	38
	39	#define CPUFREQ_TRANSITION_NOTIFIER (0)
	40	#define CPUFREQ_POLICY_NOTIFIER (1)
	41
	42
	43	/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
	44	* within the limits is used. If (cpufreq_driver->setpolicy> exists, these
	45	* two generic policies are available:
	46	*/
	47
	48	#define CPUFREQ_POLICY_POWERSAVE (1)
	49	#define CPUFREQ_POLICY_PERFORMANCE (2)
	50
	51	/* Frequency values here are CPU kHz so that hardware which doesn't run
	52	* with some frequencies can complain without having to guess what per
	53	* cent / per mille means.
b53cc6ea	54	* Maximum transition latency is in nanoseconds - if it's unknown,
1da177e4 LT	55	* CPUFREQ_ETERNAL shall be used.
	56	*/
	57
	58	struct cpufreq_governor;
	59
	60	#define CPUFREQ_ETERNAL (-1)
	61	struct cpufreq_cpuinfo {
	62	unsigned int max_freq;
	63	unsigned int min_freq;
	64	unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
	65	};
	66
	67	struct cpufreq_real_policy {
	68	unsigned int min; /* in kHz */
	69	unsigned int max; /* in kHz */
	70	unsigned int policy; /* see above */
	71	struct cpufreq_governor governor; / see below */
	72	};
	73
	74	struct cpufreq_policy {
	75	cpumask_t cpus; /* affected CPUs */
	76	unsigned int cpu; /* cpu nr of registered CPU */
	77	struct cpufreq_cpuinfo cpuinfo;/* see above */
	78
	79	unsigned int min; /* in kHz */
	80	unsigned int max; /* in kHz */
	81	unsigned int cur; /* in kHz, only needed if cpufreq
	82	* governors are used */
	83	unsigned int policy; /* see above */
	84	struct cpufreq_governor governor; / see below */
	85
83933af4	86	struct mutex lock; /* CPU ->setpolicy or ->target may
1da177e4 LT	87	only be called once a time */
	88
	89	struct work_struct update; /* if update_policy() needs to be
	90	* called, but you're in IRQ context */
	91
	92	struct cpufreq_real_policy user_policy;
	93
	94	struct kobject kobj;
	95	struct completion kobj_unregister;
	96	};
	97
	98	#define CPUFREQ_ADJUST (0)
	99	#define CPUFREQ_INCOMPATIBLE (1)
	100	#define CPUFREQ_NOTIFY (2)
	101
	102
	103	/****************** cpufreq transition notifiers *****************/
	104
	105	#define CPUFREQ_PRECHANGE (0)
	106	#define CPUFREQ_POSTCHANGE (1)
	107	#define CPUFREQ_RESUMECHANGE (8)
42d4dc3f	108	#define CPUFREQ_SUSPENDCHANGE (9)
1da177e4 LT	109
	110	struct cpufreq_freqs {
	111	unsigned int cpu; /* cpu nr */
	112	unsigned int old;
	113	unsigned int new;
	114	u8 flags; /* flags of cpufreq_driver, see below. */
	115	};
	116
	117
	118	/**
	119	* cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
	120	* @old: old value
	121	* @div: divisor
	122	* @mult: multiplier
	123	*
	124	*
	125	* new = old * mult / div
	126	*/
	127	static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
	128	{
	129	#if BITS_PER_LONG == 32
	130
	131	u64 result = ((u64) old) * ((u64) mult);
	132	do_div(result, div);
	133	return (unsigned long) result;
	134
	135	#elif BITS_PER_LONG == 64
	136
	137	unsigned long result = old * ((u64) mult);
	138	result /= div;
	139	return result;
	140
	141	#endif
	142	};
	143
	144	/*********************************************************************
	145	* CPUFREQ GOVERNORS *
	146	*********************************************************************/
	147
	148	#define CPUFREQ_GOV_START 1
	149	#define CPUFREQ_GOV_STOP 2
	150	#define CPUFREQ_GOV_LIMITS 3
	151
	152	struct cpufreq_governor {
	153	char name[CPUFREQ_NAME_LEN];
	154	int (governor) (struct cpufreq_policy policy,
	155	unsigned int event);
	156	struct list_head governor_list;
	157	struct module *owner;
	158	};
	159
	160	/* pass a target to the cpufreq driver
	161	*/
	162	extern int cpufreq_driver_target(struct cpufreq_policy *policy,
	163	unsigned int target_freq,
	164	unsigned int relation);
	165	extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
	166	unsigned int target_freq,
	167	unsigned int relation);
	168
	169
	170	/* pass an event to the cpufreq governor */
	171	int cpufreq_governor(unsigned int cpu, unsigned int event);
	172
173	int cpufreq_register_governor(struct cpufreq_governor *governor);
174	void cpufreq_unregister_governor(struct cpufreq_governor *governor);
175
176
177	/*********************************************************************
178	* CPUFREQ DRIVER INTERFACE *
179	*********************************************************************/
180
181	#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
182	#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
183
184	struct freq_attr;
185
186	struct cpufreq_driver {
187	struct module *owner;
188	char name[CPUFREQ_NAME_LEN];
189	u8 flags;
190
191	/* needed by all drivers */
192	int (init) (struct cpufreq_policy policy);
193	int (verify) (struct cpufreq_policy policy);
194
195	/* define one out of two */
196	int (setpolicy) (struct cpufreq_policy policy);
197	int (target) (struct cpufreq_policy policy,
198	unsigned int target_freq,
199	unsigned int relation);
200
201	/* should be defined, if possible */
202	unsigned int (*get) (unsigned int cpu);
203
204	/* optional */
205	int (exit) (struct cpufreq_policy policy);
e00d9967	206	int (suspend) (struct cpufreq_policy policy, pm_message_t pmsg);
1da177e4 LT	207	int (resume) (struct cpufreq_policy policy);
	208	struct freq_attr **attr;
	209	};
	210
	211	/* flags */
	212
	213	#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
	214	* all ->init() calls failed */
	215	#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
	216	* "constants" aren't affected by
	217	* frequency transitions */
42d4dc3f BH	218	#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
42d4dc3f BH	219	* mismatches */
1da177e4 LT	220
	221	int cpufreq_register_driver(struct cpufreq_driver *driver_data);
	222	int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
	223
	224
	225	void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
	226
	227
	228	static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
	229	{
	230	if (policy->min < min)
	231	policy->min = min;
	232	if (policy->max < min)
	233	policy->max = min;
	234	if (policy->min > max)
	235	policy->min = max;
	236	if (policy->max > max)
	237	policy->max = max;
	238	if (policy->min > policy->max)
	239	policy->min = policy->max;
	240	return;
	241	}
	242
	243	struct freq_attr {
	244	struct attribute attr;
	245	ssize_t (show)(struct cpufreq_policy , char *);
	246	ssize_t (store)(struct cpufreq_policy , const char *, size_t count);
	247	};
	248
	249
	250	/*********************************************************************
	251	* CPUFREQ 2.6. INTERFACE *
	252	*********************************************************************/
	253	int cpufreq_set_policy(struct cpufreq_policy *policy);
	254	int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
	255	int cpufreq_update_policy(unsigned int cpu);
	256
	257	/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
	258	unsigned int cpufreq_get(unsigned int cpu);
	259
95235ca2 VP	260	/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
	261	#ifdef CONFIG_CPU_FREQ
	262	unsigned int cpufreq_quick_get(unsigned int cpu);
	263	#else
	264	static inline unsigned int cpufreq_quick_get(unsigned int cpu)
	265	{
	266	return 0;
	267	}
	268	#endif
	269
1da177e4 LT	270
	271	/*********************************************************************
	272	* CPUFREQ DEFAULT GOVERNOR *
	273	*********************************************************************/
	274
	275
	276	#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
	277	extern struct cpufreq_governor cpufreq_gov_performance;
	278	#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
	279	#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
	280	extern struct cpufreq_governor cpufreq_gov_userspace;
	281	#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
	282	#endif
	283
	284
	285	/*********************************************************************
	286	* FREQUENCY TABLE HELPERS *
	287	*********************************************************************/
	288
	289	#define CPUFREQ_ENTRY_INVALID ~0
	290	#define CPUFREQ_TABLE_END ~1
	291
	292	struct cpufreq_frequency_table {
	293	unsigned int index; /* any */
	294	unsigned int frequency; /* kHz - doesn't need to be in ascending
	295	* order */
	296	};
	297
	298	int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
	299	struct cpufreq_frequency_table *table);
	300
	301	int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
	302	struct cpufreq_frequency_table *table);
	303
	304	int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
	305	struct cpufreq_frequency_table *table,
	306	unsigned int target_freq,
	307	unsigned int relation,
	308	unsigned int *index);
	309
	310	/* the following 3 funtions are for cpufreq core use only */
	311	struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
	312	struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
	313	void cpufreq_cpu_put (struct cpufreq_policy *data);
	314
	315	/* the following are really really optional */
	316	extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
	317
	318	void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
	319	unsigned int cpu);
	320
	321	void cpufreq_frequency_table_put_attr(unsigned int cpu);
	322
	323
	324	/*********************************************************************
	325	* UNIFIED DEBUG HELPERS *
	326	*********************************************************************/
	327
	328	#define CPUFREQ_DEBUG_CORE 1
	329	#define CPUFREQ_DEBUG_DRIVER 2
	330	#define CPUFREQ_DEBUG_GOVERNOR 4
	331
	332	#ifdef CONFIG_CPU_FREQ_DEBUG
	333
334	extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
335	const char *fmt, ...);
336
337	#else
338
339	#define cpufreq_debug_printk(msg...) do { } while(0)
340
341	#endif /* CONFIG_CPU_FREQ_DEBUG */
342
343	#endif /* _LINUX_CPUFREQ_H */