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 extern void disable_cpufreq(void);
39 #else /* CONFIG_CPU_FREQ */
40 static inline int cpufreq_register_notifier(struct notifier_block *nb,
45 static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
50 static inline void disable_cpufreq(void) { }
51 #endif /* CONFIG_CPU_FREQ */
53 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
54 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
55 * two generic policies are available:
58 #define CPUFREQ_POLICY_POWERSAVE (1)
59 #define CPUFREQ_POLICY_PERFORMANCE (2)
61 /* Frequency values here are CPU kHz so that hardware which doesn't run
62 * with some frequencies can complain without having to guess what per
63 * cent / per mille means.
64 * Maximum transition latency is in nanoseconds - if it's unknown,
65 * CPUFREQ_ETERNAL shall be used.
68 struct cpufreq_governor;
70 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
71 extern struct kobject *cpufreq_global_kobject;
73 #define CPUFREQ_ETERNAL (-1)
74 struct cpufreq_cpuinfo {
75 unsigned int max_freq;
76 unsigned int min_freq;
78 /* in 10^(-9) s = nanoseconds */
79 unsigned int transition_latency;
82 struct cpufreq_real_policy {
83 unsigned int min; /* in kHz */
84 unsigned int max; /* in kHz */
85 unsigned int policy; /* see above */
86 struct cpufreq_governor *governor; /* see below */
89 struct cpufreq_policy {
90 cpumask_var_t cpus; /* CPUs requiring sw coordination */
91 cpumask_var_t related_cpus; /* CPUs with any coordination */
92 unsigned int shared_type; /* ANY or ALL affected CPUs
94 unsigned int cpu; /* cpu nr of registered CPU */
95 struct cpufreq_cpuinfo cpuinfo;/* see above */
97 unsigned int min; /* in kHz */
98 unsigned int max; /* in kHz */
99 unsigned int cur; /* in kHz, only needed if cpufreq
100 * governors are used */
101 unsigned int policy; /* see above */
102 struct cpufreq_governor *governor; /* see below */
104 struct work_struct update; /* if update_policy() needs to be
105 * called, but you're in IRQ context */
107 struct cpufreq_real_policy user_policy;
110 struct completion kobj_unregister;
113 #define CPUFREQ_ADJUST (0)
114 #define CPUFREQ_INCOMPATIBLE (1)
115 #define CPUFREQ_NOTIFY (2)
116 #define CPUFREQ_START (3)
118 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
119 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
120 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
121 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
123 /******************** cpufreq transition notifiers *******************/
125 #define CPUFREQ_PRECHANGE (0)
126 #define CPUFREQ_POSTCHANGE (1)
127 #define CPUFREQ_RESUMECHANGE (8)
128 #define CPUFREQ_SUSPENDCHANGE (9)
130 struct cpufreq_freqs {
131 unsigned int cpu; /* cpu nr */
134 u8 flags; /* flags of cpufreq_driver, see below. */
139 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
145 * new = old * mult / div
147 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
149 #if BITS_PER_LONG == 32
151 u64 result = ((u64) old) * ((u64) mult);
153 return (unsigned long) result;
155 #elif BITS_PER_LONG == 64
157 unsigned long result = old * ((u64) mult);
164 /*********************************************************************
165 * CPUFREQ GOVERNORS *
166 *********************************************************************/
168 #define CPUFREQ_GOV_START 1
169 #define CPUFREQ_GOV_STOP 2
170 #define CPUFREQ_GOV_LIMITS 3
172 struct cpufreq_governor {
173 char name[CPUFREQ_NAME_LEN];
174 int (*governor) (struct cpufreq_policy *policy,
176 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
178 int (*store_setspeed) (struct cpufreq_policy *policy,
180 unsigned int max_transition_latency; /* HW must be able to switch to
181 next freq faster than this value in nano secs or we
182 will fallback to performance governor */
183 struct list_head governor_list;
184 struct module *owner;
188 * Pass a target to the cpufreq driver.
190 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
191 unsigned int target_freq,
192 unsigned int relation);
193 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
194 unsigned int target_freq,
195 unsigned int relation);
198 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
201 int cpufreq_register_governor(struct cpufreq_governor *governor);
202 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
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);
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_rw(_name) \
290 static struct freq_attr _name = \
291 __ATTR(_name, 0644, show_##_name, store_##_name)
294 struct attribute attr;
295 ssize_t (*show)(struct kobject *kobj,
296 struct attribute *attr, char *buf);
297 ssize_t (*store)(struct kobject *a, struct attribute *b,
298 const char *c, size_t count);
301 #define define_one_global_ro(_name) \
302 static struct global_attr _name = \
303 __ATTR(_name, 0444, show_##_name, NULL)
305 #define define_one_global_rw(_name) \
306 static struct global_attr _name = \
307 __ATTR(_name, 0644, show_##_name, store_##_name)
310 /*********************************************************************
311 * CPUFREQ 2.6. INTERFACE *
312 *********************************************************************/
313 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
314 int cpufreq_update_policy(unsigned int cpu);
316 #ifdef CONFIG_CPU_FREQ
317 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
318 unsigned int cpufreq_get(unsigned int cpu);
320 static inline unsigned int cpufreq_get(unsigned int cpu)
326 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
327 #ifdef CONFIG_CPU_FREQ
328 unsigned int cpufreq_quick_get(unsigned int cpu);
329 unsigned int cpufreq_quick_get_max(unsigned int cpu);
331 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
335 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
342 /*********************************************************************
343 * CPUFREQ DEFAULT GOVERNOR *
344 *********************************************************************/
348 Performance governor is fallback governor if any other gov failed to
349 auto load due latency restrictions
351 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
352 extern struct cpufreq_governor cpufreq_gov_performance;
354 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
355 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
356 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
357 extern struct cpufreq_governor cpufreq_gov_powersave;
358 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
359 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
360 extern struct cpufreq_governor cpufreq_gov_userspace;
361 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
362 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
363 extern struct cpufreq_governor cpufreq_gov_ondemand;
364 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
365 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
366 extern struct cpufreq_governor cpufreq_gov_conservative;
367 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
371 /*********************************************************************
372 * FREQUENCY TABLE HELPERS *
373 *********************************************************************/
375 #define CPUFREQ_ENTRY_INVALID ~0
376 #define CPUFREQ_TABLE_END ~1
378 struct cpufreq_frequency_table {
379 unsigned int index; /* any */
380 unsigned int frequency; /* kHz - doesn't need to be in ascending
384 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
385 struct cpufreq_frequency_table *table);
387 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
388 struct cpufreq_frequency_table *table);
390 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
391 struct cpufreq_frequency_table *table,
392 unsigned int target_freq,
393 unsigned int relation,
394 unsigned int *index);
396 /* the following 3 funtions are for cpufreq core use only */
397 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
398 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
399 void cpufreq_cpu_put(struct cpufreq_policy *data);
401 /* the following are really really optional */
402 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
404 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
407 void cpufreq_frequency_table_put_attr(unsigned int cpu);
410 #endif /* _LINUX_CPUFREQ_H */