2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
8 * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
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.
14 #ifndef _LINUX_CPUFREQ_H
15 #define _LINUX_CPUFREQ_H
17 #include <linux/mutex.h>
18 #include <linux/notifier.h>
19 #include <linux/threads.h>
20 #include <linux/device.h>
21 #include <linux/kobject.h>
22 #include <linux/sysfs.h>
23 #include <linux/completion.h>
24 #include <linux/workqueue.h>
25 #include <linux/cpumask.h>
26 #include <asm/div64.h>
28 #define CPUFREQ_NAME_LEN 16
31 /*********************************************************************
32 * CPUFREQ NOTIFIER INTERFACE *
33 *********************************************************************/
35 #define CPUFREQ_TRANSITION_NOTIFIER (0)
36 #define CPUFREQ_POLICY_NOTIFIER (1)
38 #ifdef CONFIG_CPU_FREQ
39 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
40 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
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 #endif /* CONFIG_CPU_FREQ */
54 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
55 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
56 * two generic policies are available:
59 #define CPUFREQ_POLICY_POWERSAVE (1)
60 #define CPUFREQ_POLICY_PERFORMANCE (2)
62 /* Frequency values here are CPU kHz so that hardware which doesn't run
63 * with some frequencies can complain without having to guess what per
64 * cent / per mille means.
65 * Maximum transition latency is in nanoseconds - if it's unknown,
66 * CPUFREQ_ETERNAL shall be used.
69 struct cpufreq_governor;
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_t cpus; /* CPUs requiring sw coordination */
87 cpumask_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);
195 int cpufreq_register_governor(struct cpufreq_governor *governor);
196 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
198 int lock_policy_rwsem_read(int cpu);
199 int lock_policy_rwsem_write(int cpu);
200 void unlock_policy_rwsem_read(int cpu);
201 void unlock_policy_rwsem_write(int cpu);
204 /*********************************************************************
205 * CPUFREQ DRIVER INTERFACE *
206 *********************************************************************/
208 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
209 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
213 struct cpufreq_driver {
214 struct module *owner;
215 char name[CPUFREQ_NAME_LEN];
218 /* needed by all drivers */
219 int (*init) (struct cpufreq_policy *policy);
220 int (*verify) (struct cpufreq_policy *policy);
222 /* define one out of two */
223 int (*setpolicy) (struct cpufreq_policy *policy);
224 int (*target) (struct cpufreq_policy *policy,
225 unsigned int target_freq,
226 unsigned int relation);
228 /* should be defined, if possible */
229 unsigned int (*get) (unsigned int cpu);
232 unsigned int (*getavg) (unsigned int cpu);
233 int (*exit) (struct cpufreq_policy *policy);
234 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
235 int (*resume) (struct cpufreq_policy *policy);
236 struct freq_attr **attr;
241 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
242 * all ->init() calls failed */
243 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
244 * "constants" aren't affected by
245 * frequency transitions */
246 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
249 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
250 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
253 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
256 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
258 if (policy->min < min)
260 if (policy->max < min)
262 if (policy->min > max)
264 if (policy->max > max)
266 if (policy->min > policy->max)
267 policy->min = policy->max;
272 struct attribute attr;
273 ssize_t (*show)(struct cpufreq_policy *, char *);
274 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
278 /*********************************************************************
279 * CPUFREQ 2.6. INTERFACE *
280 *********************************************************************/
281 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
282 int cpufreq_update_policy(unsigned int cpu);
284 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
285 unsigned int cpufreq_get(unsigned int cpu);
287 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
288 #ifdef CONFIG_CPU_FREQ
289 unsigned int cpufreq_quick_get(unsigned int cpu);
291 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
298 /*********************************************************************
299 * CPUFREQ DEFAULT GOVERNOR *
300 *********************************************************************/
304 Performance governor is fallback governor if any other gov failed to
305 auto load due latency restrictions
307 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
308 extern struct cpufreq_governor cpufreq_gov_performance;
310 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
311 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
312 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
313 extern struct cpufreq_governor cpufreq_gov_powersave;
314 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
315 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
316 extern struct cpufreq_governor cpufreq_gov_userspace;
317 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
318 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
319 extern struct cpufreq_governor cpufreq_gov_ondemand;
320 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
321 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
322 extern struct cpufreq_governor cpufreq_gov_conservative;
323 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
327 /*********************************************************************
328 * FREQUENCY TABLE HELPERS *
329 *********************************************************************/
331 #define CPUFREQ_ENTRY_INVALID ~0
332 #define CPUFREQ_TABLE_END ~1
334 struct cpufreq_frequency_table {
335 unsigned int index; /* any */
336 unsigned int frequency; /* kHz - doesn't need to be in ascending
340 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
341 struct cpufreq_frequency_table *table);
343 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
344 struct cpufreq_frequency_table *table);
346 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
347 struct cpufreq_frequency_table *table,
348 unsigned int target_freq,
349 unsigned int relation,
350 unsigned int *index);
352 /* the following 3 funtions are for cpufreq core use only */
353 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
354 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
355 void cpufreq_cpu_put (struct cpufreq_policy *data);
357 /* the following are really really optional */
358 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
360 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
363 void cpufreq_frequency_table_put_attr(unsigned int cpu);
366 /*********************************************************************
367 * UNIFIED DEBUG HELPERS *
368 *********************************************************************/
370 #define CPUFREQ_DEBUG_CORE 1
371 #define CPUFREQ_DEBUG_DRIVER 2
372 #define CPUFREQ_DEBUG_GOVERNOR 4
374 #ifdef CONFIG_CPU_FREQ_DEBUG
376 extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
377 const char *fmt, ...);
381 #define cpufreq_debug_printk(msg...) do { } while(0)
383 #endif /* CONFIG_CPU_FREQ_DEBUG */
385 #endif /* _LINUX_CPUFREQ_H */