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/config.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>
25 #define CPUFREQ_NAME_LEN 16
28 /*********************************************************************
29 * CPUFREQ NOTIFIER INTERFACE *
30 *********************************************************************/
32 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
33 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
35 #define CPUFREQ_TRANSITION_NOTIFIER (0)
36 #define CPUFREQ_POLICY_NOTIFIER (1)
39 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
40 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
41 * two generic policies are available:
44 #define CPUFREQ_POLICY_POWERSAVE (1)
45 #define CPUFREQ_POLICY_PERFORMANCE (2)
47 /* Frequency values here are CPU kHz so that hardware which doesn't run
48 * with some frequencies can complain without having to guess what per
49 * cent / per mille means.
50 * Maximum transition latency is in microseconds - if it's unknown,
51 * CPUFREQ_ETERNAL shall be used.
54 struct cpufreq_governor;
56 #define CPUFREQ_ETERNAL (-1)
57 struct cpufreq_cpuinfo {
58 unsigned int max_freq;
59 unsigned int min_freq;
60 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
63 struct cpufreq_real_policy {
64 unsigned int min; /* in kHz */
65 unsigned int max; /* in kHz */
66 unsigned int policy; /* see above */
67 struct cpufreq_governor *governor; /* see below */
70 struct cpufreq_policy {
71 unsigned int cpu; /* cpu nr */
72 struct cpufreq_cpuinfo cpuinfo;/* see above */
74 unsigned int min; /* in kHz */
75 unsigned int max; /* in kHz */
76 unsigned int cur; /* in kHz, only needed if cpufreq
77 * governors are used */
78 unsigned int policy; /* see above */
79 struct cpufreq_governor *governor; /* see below */
81 struct semaphore lock; /* CPU ->setpolicy or ->target may
82 only be called once a time */
84 struct cpufreq_real_policy user_policy;
87 struct completion kobj_unregister;
90 #define CPUFREQ_ADJUST (0)
91 #define CPUFREQ_INCOMPATIBLE (1)
92 #define CPUFREQ_NOTIFY (2)
95 /******************** cpufreq transition notifiers *******************/
97 #define CPUFREQ_PRECHANGE (0)
98 #define CPUFREQ_POSTCHANGE (1)
100 struct cpufreq_freqs {
101 unsigned int cpu; /* cpu nr */
108 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
114 * new = old * mult / div
116 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
118 #if BITS_PER_LONG == 32
120 u64 result = ((u64) old) * ((u64) mult);
122 return (unsigned long) result;
124 #elif BITS_PER_LONG == 64
126 unsigned long result = old * ((u64) mult);
133 /*********************************************************************
134 * CPUFREQ GOVERNORS *
135 *********************************************************************/
137 #define CPUFREQ_GOV_START 1
138 #define CPUFREQ_GOV_STOP 2
139 #define CPUFREQ_GOV_LIMITS 3
141 struct cpufreq_governor {
142 char name[CPUFREQ_NAME_LEN];
143 int (*governor) (struct cpufreq_policy *policy,
145 struct list_head governor_list;
146 struct module *owner;
149 /* pass a target to the cpufreq driver
151 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
152 unsigned int target_freq,
153 unsigned int relation);
154 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
155 unsigned int target_freq,
156 unsigned int relation);
159 /* pass an event to the cpufreq governor */
160 int cpufreq_governor(unsigned int cpu, unsigned int event);
162 int cpufreq_register_governor(struct cpufreq_governor *governor);
163 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
166 /*********************************************************************
167 * CPUFREQ DRIVER INTERFACE *
168 *********************************************************************/
170 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
171 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
175 struct cpufreq_driver {
176 struct module *owner;
177 char name[CPUFREQ_NAME_LEN];
180 /* needed by all drivers */
181 int (*init) (struct cpufreq_policy *policy);
182 int (*verify) (struct cpufreq_policy *policy);
184 /* define one out of two */
185 int (*setpolicy) (struct cpufreq_policy *policy);
186 int (*target) (struct cpufreq_policy *policy,
187 unsigned int target_freq,
188 unsigned int relation);
191 int (*exit) (struct cpufreq_policy *policy);
192 int (*resume) (struct cpufreq_policy *policy);
193 struct freq_attr **attr;
198 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
199 all ->init() calls failed */
201 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
202 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
205 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
208 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
210 if (policy->min < min)
212 if (policy->max < min)
214 if (policy->min > max)
216 if (policy->max > max)
218 if (policy->min > policy->max)
219 policy->min = policy->max;
224 struct attribute attr;
225 ssize_t (*show)(struct cpufreq_policy *, char *);
226 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
230 /*********************************************************************
231 * CPUFREQ 2.6. INTERFACE *
232 *********************************************************************/
233 int cpufreq_set_policy(struct cpufreq_policy *policy);
234 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
235 int cpufreq_update_policy(unsigned int cpu);
237 /* the proc_intf.c needs this */
238 int cpufreq_parse_governor (char *str_governor, unsigned int *policy, struct cpufreq_governor **governor);
241 /*********************************************************************
242 * CPUFREQ USERSPACE GOVERNOR *
243 *********************************************************************/
244 int cpufreq_gov_userspace_init(void);
246 #ifdef CONFIG_CPU_FREQ_24_API
248 int cpufreq_setmax(unsigned int cpu);
249 int cpufreq_set(unsigned int kHz, unsigned int cpu);
250 unsigned int cpufreq_get(unsigned int cpu);
255 CPU_NR = 1, /* compatibilty reasons */
290 /* /proc/sys/cpu/{0,1,...,(NR_CPUS-1)} */
297 #endif /* CONFIG_CPU_FREQ_24_API */
300 /*********************************************************************
301 * CPUFREQ DEFAULT GOVERNOR *
302 *********************************************************************/
305 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
306 extern struct cpufreq_governor cpufreq_gov_performance;
307 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
308 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
309 extern struct cpufreq_governor cpufreq_gov_userspace;
310 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
314 /*********************************************************************
315 * FREQUENCY TABLE HELPERS *
316 *********************************************************************/
318 #define CPUFREQ_ENTRY_INVALID ~0
319 #define CPUFREQ_TABLE_END ~1
321 struct cpufreq_frequency_table {
322 unsigned int index; /* any */
323 unsigned int frequency; /* kHz - doesn't need to be in ascending
327 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
328 struct cpufreq_frequency_table *table);
330 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
331 struct cpufreq_frequency_table *table);
333 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
334 struct cpufreq_frequency_table *table,
335 unsigned int target_freq,
336 unsigned int relation,
337 unsigned int *index);
339 /* the following are really really optional */
340 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
342 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
345 void cpufreq_frequency_table_put_attr(unsigned int cpu);
348 #endif /* _LINUX_CPUFREQ_H */