2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #ifndef _LINUX_CPUFREQ_H
12 #define _LINUX_CPUFREQ_H
14 #include <linux/mutex.h>
15 #include <linux/notifier.h>
16 #include <linux/threads.h>
17 #include <linux/device.h>
18 #include <linux/kobject.h>
19 #include <linux/sysfs.h>
20 #include <linux/completion.h>
21 #include <linux/workqueue.h>
22 #include <linux/cpumask.h>
23 #include <asm/div64.h>
25 #define CPUFREQ_NAME_LEN 16
28 /*********************************************************************
29 * CPUFREQ NOTIFIER INTERFACE *
30 *********************************************************************/
32 #define CPUFREQ_TRANSITION_NOTIFIER (0)
33 #define CPUFREQ_POLICY_NOTIFIER (1)
35 #ifdef CONFIG_CPU_FREQ
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 #else /* CONFIG_CPU_FREQ */
39 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
44 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
49 #endif /* CONFIG_CPU_FREQ */
51 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
52 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
53 * two generic policies are available:
56 #define CPUFREQ_POLICY_POWERSAVE (1)
57 #define CPUFREQ_POLICY_PERFORMANCE (2)
59 /* Frequency values here are CPU kHz so that hardware which doesn't run
60 * with some frequencies can complain without having to guess what per
61 * cent / per mille means.
62 * Maximum transition latency is in nanoseconds - if it's unknown,
63 * CPUFREQ_ETERNAL shall be used.
66 struct cpufreq_governor
;
68 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
69 extern struct kobject
*cpufreq_global_kobject
;
71 #define CPUFREQ_ETERNAL (-1)
72 struct cpufreq_cpuinfo
{
73 unsigned int max_freq
;
74 unsigned int min_freq
;
75 unsigned int transition_latency
; /* in 10^(-9) s = nanoseconds */
78 struct cpufreq_real_policy
{
79 unsigned int min
; /* in kHz */
80 unsigned int max
; /* in kHz */
81 unsigned int policy
; /* see above */
82 struct cpufreq_governor
*governor
; /* see below */
85 struct cpufreq_policy
{
86 cpumask_var_t cpus
; /* CPUs requiring sw coordination */
87 cpumask_var_t related_cpus
; /* CPUs with any coordination */
88 unsigned int shared_type
; /* ANY or ALL affected CPUs
90 unsigned int cpu
; /* cpu nr of registered CPU */
91 struct cpufreq_cpuinfo cpuinfo
;/* see above */
93 unsigned int min
; /* in kHz */
94 unsigned int max
; /* in kHz */
95 unsigned int cur
; /* in kHz, only needed if cpufreq
96 * governors are used */
97 unsigned int policy
; /* see above */
98 struct cpufreq_governor
*governor
; /* see below */
100 struct work_struct update
; /* if update_policy() needs to be
101 * called, but you're in IRQ context */
103 struct cpufreq_real_policy user_policy
;
106 struct completion kobj_unregister
;
109 #define CPUFREQ_ADJUST (0)
110 #define CPUFREQ_INCOMPATIBLE (1)
111 #define CPUFREQ_NOTIFY (2)
112 #define CPUFREQ_START (3)
114 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
115 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
116 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
117 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
119 /******************** cpufreq transition notifiers *******************/
121 #define CPUFREQ_PRECHANGE (0)
122 #define CPUFREQ_POSTCHANGE (1)
123 #define CPUFREQ_RESUMECHANGE (8)
124 #define CPUFREQ_SUSPENDCHANGE (9)
126 struct cpufreq_freqs
{
127 unsigned int cpu
; /* cpu nr */
130 u8 flags
; /* flags of cpufreq_driver, see below. */
135 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
141 * new = old * mult / div
143 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
, u_int mult
)
145 #if BITS_PER_LONG == 32
147 u64 result
= ((u64
) old
) * ((u64
) mult
);
149 return (unsigned long) result
;
151 #elif BITS_PER_LONG == 64
153 unsigned long result
= old
* ((u64
) mult
);
160 /*********************************************************************
161 * CPUFREQ GOVERNORS *
162 *********************************************************************/
164 #define CPUFREQ_GOV_START 1
165 #define CPUFREQ_GOV_STOP 2
166 #define CPUFREQ_GOV_LIMITS 3
168 struct cpufreq_governor
{
169 char name
[CPUFREQ_NAME_LEN
];
170 int (*governor
) (struct cpufreq_policy
*policy
,
172 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
174 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
176 unsigned int max_transition_latency
; /* HW must be able to switch to
177 next freq faster than this value in nano secs or we
178 will fallback to performance governor */
179 struct list_head governor_list
;
180 struct module
*owner
;
183 /* pass a target to the cpufreq driver
185 extern int cpufreq_driver_target(struct cpufreq_policy
*policy
,
186 unsigned int target_freq
,
187 unsigned int relation
);
188 extern int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
189 unsigned int target_freq
,
190 unsigned int relation
);
193 extern int __cpufreq_driver_getavg(struct cpufreq_policy
*policy
,
196 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
197 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
199 int lock_policy_rwsem_read(int cpu
);
200 int lock_policy_rwsem_write(int cpu
);
201 void unlock_policy_rwsem_read(int cpu
);
202 void unlock_policy_rwsem_write(int cpu
);
205 /*********************************************************************
206 * CPUFREQ DRIVER INTERFACE *
207 *********************************************************************/
209 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
210 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
214 struct cpufreq_driver
{
215 struct module
*owner
;
216 char name
[CPUFREQ_NAME_LEN
];
219 /* needed by all drivers */
220 int (*init
) (struct cpufreq_policy
*policy
);
221 int (*verify
) (struct cpufreq_policy
*policy
);
223 /* define one out of two */
224 int (*setpolicy
) (struct cpufreq_policy
*policy
);
225 int (*target
) (struct cpufreq_policy
*policy
,
226 unsigned int target_freq
,
227 unsigned int relation
);
229 /* should be defined, if possible */
230 unsigned int (*get
) (unsigned int cpu
);
233 unsigned int (*getavg
) (struct cpufreq_policy
*policy
,
235 int (*bios_limit
) (int cpu
, unsigned int *limit
);
237 int (*exit
) (struct cpufreq_policy
*policy
);
238 int (*suspend
) (struct cpufreq_policy
*policy
, pm_message_t pmsg
);
239 int (*resume
) (struct cpufreq_policy
*policy
);
240 struct freq_attr
**attr
;
245 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
246 * all ->init() calls failed */
247 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
248 * "constants" aren't affected by
249 * frequency transitions */
250 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
253 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
254 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
257 void cpufreq_notify_transition(struct cpufreq_freqs
*freqs
, unsigned int state
);
260 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
, unsigned int min
, unsigned int max
)
262 if (policy
->min
< min
)
264 if (policy
->max
< min
)
266 if (policy
->min
> max
)
268 if (policy
->max
> max
)
270 if (policy
->min
> policy
->max
)
271 policy
->min
= policy
->max
;
276 struct attribute attr
;
277 ssize_t (*show
)(struct cpufreq_policy
*, char *);
278 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
281 #define cpufreq_freq_attr_ro(_name) \
282 static struct freq_attr _name = \
283 __ATTR(_name, 0444, show_##_name, NULL)
285 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
286 static struct freq_attr _name = \
287 __ATTR(_name, _perm, show_##_name, NULL)
289 #define cpufreq_freq_attr_ro_old(_name) \
290 static struct freq_attr _name##_old = \
291 __ATTR(_name, 0444, show_##_name##_old, NULL)
293 #define cpufreq_freq_attr_rw(_name) \
294 static struct freq_attr _name = \
295 __ATTR(_name, 0644, show_##_name, store_##_name)
297 #define cpufreq_freq_attr_rw_old(_name) \
298 static struct freq_attr _name##_old = \
299 __ATTR(_name, 0644, show_##_name##_old, store_##_name##_old)
303 struct attribute attr
;
304 ssize_t (*show
)(struct kobject
*kobj
,
305 struct attribute
*attr
, char *buf
);
306 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
307 const char *c
, size_t count
);
310 #define define_one_global_ro(_name) \
311 static struct global_attr _name = \
312 __ATTR(_name, 0444, show_##_name, NULL)
314 #define define_one_global_rw(_name) \
315 static struct global_attr _name = \
316 __ATTR(_name, 0644, show_##_name, store_##_name)
319 /*********************************************************************
320 * CPUFREQ 2.6. INTERFACE *
321 *********************************************************************/
322 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
323 int cpufreq_update_policy(unsigned int cpu
);
325 #ifdef CONFIG_CPU_FREQ
326 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
327 unsigned int cpufreq_get(unsigned int cpu
);
329 static inline unsigned int cpufreq_get(unsigned int cpu
)
335 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
336 #ifdef CONFIG_CPU_FREQ
337 unsigned int cpufreq_quick_get(unsigned int cpu
);
339 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
346 /*********************************************************************
347 * CPUFREQ DEFAULT GOVERNOR *
348 *********************************************************************/
352 Performance governor is fallback governor if any other gov failed to
353 auto load due latency restrictions
355 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
356 extern struct cpufreq_governor cpufreq_gov_performance
;
358 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
359 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
360 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
361 extern struct cpufreq_governor cpufreq_gov_powersave
;
362 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
363 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
364 extern struct cpufreq_governor cpufreq_gov_userspace
;
365 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
366 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
367 extern struct cpufreq_governor cpufreq_gov_ondemand
;
368 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
369 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
370 extern struct cpufreq_governor cpufreq_gov_conservative
;
371 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
375 /*********************************************************************
376 * FREQUENCY TABLE HELPERS *
377 *********************************************************************/
379 #define CPUFREQ_ENTRY_INVALID ~0
380 #define CPUFREQ_TABLE_END ~1
382 struct cpufreq_frequency_table
{
383 unsigned int index
; /* any */
384 unsigned int frequency
; /* kHz - doesn't need to be in ascending
388 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
389 struct cpufreq_frequency_table
*table
);
391 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
392 struct cpufreq_frequency_table
*table
);
394 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
395 struct cpufreq_frequency_table
*table
,
396 unsigned int target_freq
,
397 unsigned int relation
,
398 unsigned int *index
);
400 /* the following 3 funtions are for cpufreq core use only */
401 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
402 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
403 void cpufreq_cpu_put (struct cpufreq_policy
*data
);
405 /* the following are really really optional */
406 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
408 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table
*table
,
411 void cpufreq_frequency_table_put_attr(unsigned int cpu
);
414 /*********************************************************************
415 * UNIFIED DEBUG HELPERS *
416 *********************************************************************/
418 #define CPUFREQ_DEBUG_CORE 1
419 #define CPUFREQ_DEBUG_DRIVER 2
420 #define CPUFREQ_DEBUG_GOVERNOR 4
422 #ifdef CONFIG_CPU_FREQ_DEBUG
424 extern void cpufreq_debug_printk(unsigned int type
, const char *prefix
,
425 const char *fmt
, ...);
429 #define cpufreq_debug_printk(msg...) do { } while(0)
431 #endif /* CONFIG_CPU_FREQ_DEBUG */
433 #endif /* _LINUX_CPUFREQ_H */