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 <asm/cputime.h>
15 #include <linux/mutex.h>
16 #include <linux/notifier.h>
17 #include <linux/threads.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
26 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
27 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
30 /*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
34 #define CPUFREQ_TRANSITION_NOTIFIER (0)
35 #define CPUFREQ_POLICY_NOTIFIER (1)
37 #ifdef CONFIG_CPU_FREQ
38 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
39 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
40 extern void disable_cpufreq(void);
41 #else /* CONFIG_CPU_FREQ */
42 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
47 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
52 static inline void disable_cpufreq(void) { }
53 #endif /* CONFIG_CPU_FREQ */
55 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
56 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
57 * two generic policies are available:
60 #define CPUFREQ_POLICY_POWERSAVE (1)
61 #define CPUFREQ_POLICY_PERFORMANCE (2)
63 /* Frequency values here are CPU kHz so that hardware which doesn't run
64 * with some frequencies can complain without having to guess what per
65 * cent / per mille means.
66 * Maximum transition latency is in nanoseconds - if it's unknown,
67 * CPUFREQ_ETERNAL shall be used.
70 struct cpufreq_governor
;
72 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
73 extern struct kobject
*cpufreq_global_kobject
;
75 #define CPUFREQ_ETERNAL (-1)
76 struct cpufreq_cpuinfo
{
77 unsigned int max_freq
;
78 unsigned int min_freq
;
80 /* in 10^(-9) s = nanoseconds */
81 unsigned int transition_latency
;
84 struct cpufreq_real_policy
{
85 unsigned int min
; /* in kHz */
86 unsigned int max
; /* in kHz */
87 unsigned int policy
; /* see above */
88 struct cpufreq_governor
*governor
; /* see below */
91 struct cpufreq_policy
{
92 cpumask_var_t cpus
; /* CPUs requiring sw coordination */
93 cpumask_var_t related_cpus
; /* CPUs with any coordination */
94 unsigned int shared_type
; /* ANY or ALL affected CPUs
96 unsigned int cpu
; /* cpu nr of registered CPU */
97 struct cpufreq_cpuinfo cpuinfo
;/* see above */
99 unsigned int min
; /* in kHz */
100 unsigned int max
; /* in kHz */
101 unsigned int cur
; /* in kHz, only needed if cpufreq
102 * governors are used */
103 unsigned int policy
; /* see above */
104 struct cpufreq_governor
*governor
; /* see below */
106 struct work_struct update
; /* if update_policy() needs to be
107 * called, but you're in IRQ context */
109 struct cpufreq_real_policy user_policy
;
112 struct completion kobj_unregister
;
115 #define CPUFREQ_ADJUST (0)
116 #define CPUFREQ_INCOMPATIBLE (1)
117 #define CPUFREQ_NOTIFY (2)
118 #define CPUFREQ_START (3)
120 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
121 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
122 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
123 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
125 /******************** cpufreq transition notifiers *******************/
127 #define CPUFREQ_PRECHANGE (0)
128 #define CPUFREQ_POSTCHANGE (1)
129 #define CPUFREQ_RESUMECHANGE (8)
130 #define CPUFREQ_SUSPENDCHANGE (9)
132 struct cpufreq_freqs
{
133 unsigned int cpu
; /* cpu nr */
136 u8 flags
; /* flags of cpufreq_driver, see below. */
141 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
147 * new = old * mult / div
149 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
, u_int mult
)
151 #if BITS_PER_LONG == 32
153 u64 result
= ((u64
) old
) * ((u64
) mult
);
155 return (unsigned long) result
;
157 #elif BITS_PER_LONG == 64
159 unsigned long result
= old
* ((u64
) mult
);
166 /*********************************************************************
167 * CPUFREQ GOVERNORS *
168 *********************************************************************/
170 #define CPUFREQ_GOV_START 1
171 #define CPUFREQ_GOV_STOP 2
172 #define CPUFREQ_GOV_LIMITS 3
174 struct cpufreq_governor
{
175 char name
[CPUFREQ_NAME_LEN
];
176 int (*governor
) (struct cpufreq_policy
*policy
,
178 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
180 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
182 unsigned int max_transition_latency
; /* HW must be able to switch to
183 next freq faster than this value in nano secs or we
184 will fallback to performance governor */
185 struct list_head governor_list
;
186 struct module
*owner
;
190 * Pass a target to the cpufreq driver.
192 extern int cpufreq_driver_target(struct cpufreq_policy
*policy
,
193 unsigned int target_freq
,
194 unsigned int relation
);
195 extern int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
196 unsigned int target_freq
,
197 unsigned int relation
);
200 extern int __cpufreq_driver_getavg(struct cpufreq_policy
*policy
,
203 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
204 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
207 /*********************************************************************
208 * CPUFREQ DRIVER INTERFACE *
209 *********************************************************************/
211 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
212 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
216 struct cpufreq_driver
{
217 struct module
*owner
;
218 char name
[CPUFREQ_NAME_LEN
];
221 /* needed by all drivers */
222 int (*init
) (struct cpufreq_policy
*policy
);
223 int (*verify
) (struct cpufreq_policy
*policy
);
225 /* define one out of two */
226 int (*setpolicy
) (struct cpufreq_policy
*policy
);
227 int (*target
) (struct cpufreq_policy
*policy
,
228 unsigned int target_freq
,
229 unsigned int relation
);
231 /* should be defined, if possible */
232 unsigned int (*get
) (unsigned int cpu
);
235 unsigned int (*getavg
) (struct cpufreq_policy
*policy
,
237 int (*bios_limit
) (int cpu
, unsigned int *limit
);
239 int (*exit
) (struct cpufreq_policy
*policy
);
240 int (*suspend
) (struct cpufreq_policy
*policy
);
241 int (*resume
) (struct cpufreq_policy
*policy
);
242 struct freq_attr
**attr
;
247 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
248 * all ->init() calls failed */
249 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
250 * "constants" aren't affected by
251 * frequency transitions */
252 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
255 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
256 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
259 void cpufreq_notify_transition(struct cpufreq_freqs
*freqs
, unsigned int state
);
262 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
, unsigned int min
, unsigned int max
)
264 if (policy
->min
< min
)
266 if (policy
->max
< min
)
268 if (policy
->min
> max
)
270 if (policy
->max
> max
)
272 if (policy
->min
> policy
->max
)
273 policy
->min
= policy
->max
;
278 struct attribute attr
;
279 ssize_t (*show
)(struct cpufreq_policy
*, char *);
280 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
283 #define cpufreq_freq_attr_ro(_name) \
284 static struct freq_attr _name = \
285 __ATTR(_name, 0444, show_##_name, NULL)
287 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
288 static struct freq_attr _name = \
289 __ATTR(_name, _perm, show_##_name, NULL)
291 #define cpufreq_freq_attr_rw(_name) \
292 static struct freq_attr _name = \
293 __ATTR(_name, 0644, show_##_name, store_##_name)
296 struct attribute attr
;
297 ssize_t (*show
)(struct kobject
*kobj
,
298 struct attribute
*attr
, char *buf
);
299 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
300 const char *c
, size_t count
);
303 #define define_one_global_ro(_name) \
304 static struct global_attr _name = \
305 __ATTR(_name, 0444, show_##_name, NULL)
307 #define define_one_global_rw(_name) \
308 static struct global_attr _name = \
309 __ATTR(_name, 0644, show_##_name, store_##_name)
312 /*********************************************************************
313 * CPUFREQ 2.6. INTERFACE *
314 *********************************************************************/
315 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
316 int cpufreq_update_policy(unsigned int cpu
);
318 #ifdef CONFIG_CPU_FREQ
319 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
320 unsigned int cpufreq_get(unsigned int cpu
);
322 static inline unsigned int cpufreq_get(unsigned int cpu
)
328 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
329 #ifdef CONFIG_CPU_FREQ
330 unsigned int cpufreq_quick_get(unsigned int cpu
);
331 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
333 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
337 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
344 /*********************************************************************
345 * CPUFREQ DEFAULT GOVERNOR *
346 *********************************************************************/
350 Performance governor is fallback governor if any other gov failed to
351 auto load due latency restrictions
353 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
354 extern struct cpufreq_governor cpufreq_gov_performance
;
356 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
357 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
358 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
359 extern struct cpufreq_governor cpufreq_gov_powersave
;
360 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
361 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
362 extern struct cpufreq_governor cpufreq_gov_userspace
;
363 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
365 extern struct cpufreq_governor cpufreq_gov_ondemand
;
366 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
367 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
368 extern struct cpufreq_governor cpufreq_gov_conservative
;
369 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
373 /*********************************************************************
374 * FREQUENCY TABLE HELPERS *
375 *********************************************************************/
377 #define CPUFREQ_ENTRY_INVALID ~0
378 #define CPUFREQ_TABLE_END ~1
380 struct cpufreq_frequency_table
{
381 unsigned int index
; /* any */
382 unsigned int frequency
; /* kHz - doesn't need to be in ascending
386 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
387 struct cpufreq_frequency_table
*table
);
389 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
390 struct cpufreq_frequency_table
*table
);
392 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
393 struct cpufreq_frequency_table
*table
,
394 unsigned int target_freq
,
395 unsigned int relation
,
396 unsigned int *index
);
398 /* the following 3 funtions are for cpufreq core use only */
399 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
400 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
401 void cpufreq_cpu_put(struct cpufreq_policy
*data
);
403 /* the following are really really optional */
404 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
406 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table
*table
,
409 void cpufreq_frequency_table_put_attr(unsigned int cpu
);
410 #endif /* _LINUX_CPUFREQ_H */