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 /* CPUs sharing clock, require sw coordination */
93 cpumask_var_t cpus; /* Online CPUs only */
94 cpumask_var_t related_cpus; /* Online + Offline CPUs */
96 unsigned int shared_type; /* ANY or ALL affected CPUs
98 unsigned int cpu; /* cpu nr of CPU managing this policy */
99 unsigned int last_cpu; /* cpu nr of previous CPU that managed
101 struct cpufreq_cpuinfo cpuinfo;/* see above */
103 unsigned int min; /* in kHz */
104 unsigned int max; /* in kHz */
105 unsigned int cur; /* in kHz, only needed if cpufreq
106 * governors are used */
107 unsigned int policy; /* see above */
108 struct cpufreq_governor *governor; /* see below */
110 struct work_struct update; /* if update_policy() needs to be
111 * called, but you're in IRQ context */
113 struct cpufreq_real_policy user_policy;
116 struct completion kobj_unregister;
119 #define CPUFREQ_ADJUST (0)
120 #define CPUFREQ_INCOMPATIBLE (1)
121 #define CPUFREQ_NOTIFY (2)
122 #define CPUFREQ_START (3)
123 #define CPUFREQ_UPDATE_POLICY_CPU (4)
125 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
126 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
127 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
128 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
130 /******************** cpufreq transition notifiers *******************/
132 #define CPUFREQ_PRECHANGE (0)
133 #define CPUFREQ_POSTCHANGE (1)
134 #define CPUFREQ_RESUMECHANGE (8)
135 #define CPUFREQ_SUSPENDCHANGE (9)
137 struct cpufreq_freqs {
138 unsigned int cpu; /* cpu nr */
141 u8 flags; /* flags of cpufreq_driver, see below. */
146 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
152 * new = old * mult / div
154 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
156 #if BITS_PER_LONG == 32
158 u64 result = ((u64) old) * ((u64) mult);
160 return (unsigned long) result;
162 #elif BITS_PER_LONG == 64
164 unsigned long result = old * ((u64) mult);
171 /*********************************************************************
172 * CPUFREQ GOVERNORS *
173 *********************************************************************/
175 #define CPUFREQ_GOV_START 1
176 #define CPUFREQ_GOV_STOP 2
177 #define CPUFREQ_GOV_LIMITS 3
179 struct cpufreq_governor {
180 char name[CPUFREQ_NAME_LEN];
181 int (*governor) (struct cpufreq_policy *policy,
183 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
185 int (*store_setspeed) (struct cpufreq_policy *policy,
187 unsigned int max_transition_latency; /* HW must be able to switch to
188 next freq faster than this value in nano secs or we
189 will fallback to performance governor */
190 struct list_head governor_list;
191 struct module *owner;
195 * Pass a target to the cpufreq driver.
197 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
198 unsigned int target_freq,
199 unsigned int relation);
200 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
201 unsigned int target_freq,
202 unsigned int relation);
205 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
208 int cpufreq_register_governor(struct cpufreq_governor *governor);
209 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
212 /*********************************************************************
213 * CPUFREQ DRIVER INTERFACE *
214 *********************************************************************/
216 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
217 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
221 struct cpufreq_driver {
222 struct module *owner;
223 char name[CPUFREQ_NAME_LEN];
226 /* needed by all drivers */
227 int (*init) (struct cpufreq_policy *policy);
228 int (*verify) (struct cpufreq_policy *policy);
230 /* define one out of two */
231 int (*setpolicy) (struct cpufreq_policy *policy);
232 int (*target) (struct cpufreq_policy *policy,
233 unsigned int target_freq,
234 unsigned int relation);
236 /* should be defined, if possible */
237 unsigned int (*get) (unsigned int cpu);
240 unsigned int (*getavg) (struct cpufreq_policy *policy,
242 int (*bios_limit) (int cpu, unsigned int *limit);
244 int (*exit) (struct cpufreq_policy *policy);
245 int (*suspend) (struct cpufreq_policy *policy);
246 int (*resume) (struct cpufreq_policy *policy);
247 struct freq_attr **attr;
252 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
253 * all ->init() calls failed */
254 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
255 * "constants" aren't affected by
256 * frequency transitions */
257 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
260 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
261 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
264 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
267 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
269 if (policy->min < min)
271 if (policy->max < min)
273 if (policy->min > max)
275 if (policy->max > max)
277 if (policy->min > policy->max)
278 policy->min = policy->max;
283 struct attribute attr;
284 ssize_t (*show)(struct cpufreq_policy *, char *);
285 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
288 #define cpufreq_freq_attr_ro(_name) \
289 static struct freq_attr _name = \
290 __ATTR(_name, 0444, show_##_name, NULL)
292 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
293 static struct freq_attr _name = \
294 __ATTR(_name, _perm, show_##_name, NULL)
296 #define cpufreq_freq_attr_rw(_name) \
297 static struct freq_attr _name = \
298 __ATTR(_name, 0644, show_##_name, store_##_name)
301 struct attribute attr;
302 ssize_t (*show)(struct kobject *kobj,
303 struct attribute *attr, char *buf);
304 ssize_t (*store)(struct kobject *a, struct attribute *b,
305 const char *c, size_t count);
308 #define define_one_global_ro(_name) \
309 static struct global_attr _name = \
310 __ATTR(_name, 0444, show_##_name, NULL)
312 #define define_one_global_rw(_name) \
313 static struct global_attr _name = \
314 __ATTR(_name, 0644, show_##_name, store_##_name)
316 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
317 void cpufreq_cpu_put(struct cpufreq_policy *data);
318 const char *cpufreq_get_current_driver(void);
320 /*********************************************************************
321 * CPUFREQ 2.6. INTERFACE *
322 *********************************************************************/
323 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
324 int cpufreq_update_policy(unsigned int cpu);
326 #ifdef CONFIG_CPU_FREQ
327 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
328 unsigned int cpufreq_get(unsigned int cpu);
330 static inline unsigned int cpufreq_get(unsigned int cpu)
336 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
337 #ifdef CONFIG_CPU_FREQ
338 unsigned int cpufreq_quick_get(unsigned int cpu);
339 unsigned int cpufreq_quick_get_max(unsigned int cpu);
341 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
345 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
352 /*********************************************************************
353 * CPUFREQ DEFAULT GOVERNOR *
354 *********************************************************************/
358 Performance governor is fallback governor if any other gov failed to
359 auto load due latency restrictions
361 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
362 extern struct cpufreq_governor cpufreq_gov_performance;
364 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
365 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
366 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
367 extern struct cpufreq_governor cpufreq_gov_powersave;
368 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
369 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
370 extern struct cpufreq_governor cpufreq_gov_userspace;
371 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
372 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
373 extern struct cpufreq_governor cpufreq_gov_ondemand;
374 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
375 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
376 extern struct cpufreq_governor cpufreq_gov_conservative;
377 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
381 /*********************************************************************
382 * FREQUENCY TABLE HELPERS *
383 *********************************************************************/
385 #define CPUFREQ_ENTRY_INVALID ~0
386 #define CPUFREQ_TABLE_END ~1
388 struct cpufreq_frequency_table {
389 unsigned int index; /* any */
390 unsigned int frequency; /* kHz - doesn't need to be in ascending
394 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
395 struct cpufreq_frequency_table *table);
397 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
398 struct cpufreq_frequency_table *table);
400 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
401 struct cpufreq_frequency_table *table,
402 unsigned int target_freq,
403 unsigned int relation,
404 unsigned int *index);
406 /* the following 3 funtions are for cpufreq core use only */
407 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
409 /* the following are really really optional */
410 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
412 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
414 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy);
416 void cpufreq_frequency_table_put_attr(unsigned int cpu);
417 #endif /* _LINUX_CPUFREQ_H */