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1/*
2 * linux/include/linux/cpufreq.h
3 *
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6 *
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.
10 */
11#ifndef _LINUX_CPUFREQ_H
12#define _LINUX_CPUFREQ_H
13
14#include <linux/mutex.h>
15#include <linux/notifier.h>
16#include <linux/threads.h>
17#include <linux/kobject.h>
18#include <linux/sysfs.h>
19#include <linux/completion.h>
20#include <linux/workqueue.h>
21#include <linux/cpumask.h>
22#include <asm/div64.h>
23
24#define CPUFREQ_NAME_LEN 16
25
26
27/*********************************************************************
28 * CPUFREQ NOTIFIER INTERFACE *
29 *********************************************************************/
30
31#define CPUFREQ_TRANSITION_NOTIFIER (0)
32#define CPUFREQ_POLICY_NOTIFIER (1)
33
34#ifdef CONFIG_CPU_FREQ
35int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
36int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
37extern void disable_cpufreq(void);
38#else /* CONFIG_CPU_FREQ */
39static inline int cpufreq_register_notifier(struct notifier_block *nb,
40 unsigned int list)
41{
42 return 0;
43}
44static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
45 unsigned int list)
46{
47 return 0;
48}
49static inline void disable_cpufreq(void) { }
50#endif /* CONFIG_CPU_FREQ */
51
52/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
53 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
54 * two generic policies are available:
55 */
56
57#define CPUFREQ_POLICY_POWERSAVE (1)
58#define CPUFREQ_POLICY_PERFORMANCE (2)
59
60/* Frequency values here are CPU kHz so that hardware which doesn't run
61 * with some frequencies can complain without having to guess what per
62 * cent / per mille means.
63 * Maximum transition latency is in nanoseconds - if it's unknown,
64 * CPUFREQ_ETERNAL shall be used.
65 */
66
67struct cpufreq_governor;
68
69/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
70extern struct kobject *cpufreq_global_kobject;
71
72#define CPUFREQ_ETERNAL (-1)
73struct cpufreq_cpuinfo {
74 unsigned int max_freq;
75 unsigned int min_freq;
76
77 /* in 10^(-9) s = nanoseconds */
78 unsigned int transition_latency;
79};
80
81struct cpufreq_real_policy {
82 unsigned int min; /* in kHz */
83 unsigned int max; /* in kHz */
84 unsigned int policy; /* see above */
85 struct cpufreq_governor *governor; /* see below */
86};
87
88struct cpufreq_policy {
89 cpumask_var_t cpus; /* CPUs requiring sw coordination */
90 cpumask_var_t related_cpus; /* CPUs with any coordination */
91 unsigned int shared_type; /* ANY or ALL affected CPUs
92 should set cpufreq */
93 unsigned int cpu; /* cpu nr of registered CPU */
94 struct cpufreq_cpuinfo cpuinfo;/* see above */
95
96 unsigned int min; /* in kHz */
97 unsigned int max; /* in kHz */
98 unsigned int cur; /* in kHz, only needed if cpufreq
99 * governors are used */
100 unsigned int policy; /* see above */
101 struct cpufreq_governor *governor; /* see below */
102
103 struct work_struct update; /* if update_policy() needs to be
104 * called, but you're in IRQ context */
105
106 struct cpufreq_real_policy user_policy;
107
108 struct kobject kobj;
109 struct completion kobj_unregister;
110};
111
112#define CPUFREQ_ADJUST (0)
113#define CPUFREQ_INCOMPATIBLE (1)
114#define CPUFREQ_NOTIFY (2)
115#define CPUFREQ_START (3)
116
117#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
118#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
119#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
120#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
121
122/******************** cpufreq transition notifiers *******************/
123
124#define CPUFREQ_PRECHANGE (0)
125#define CPUFREQ_POSTCHANGE (1)
126#define CPUFREQ_RESUMECHANGE (8)
127#define CPUFREQ_SUSPENDCHANGE (9)
128
129struct cpufreq_freqs {
130 unsigned int cpu; /* cpu nr */
131 unsigned int old;
132 unsigned int new;
133 u8 flags; /* flags of cpufreq_driver, see below. */
134};
135
136
137/**
138 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
139 * @old: old value
140 * @div: divisor
141 * @mult: multiplier
142 *
143 *
144 * new = old * mult / div
145 */
146static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
147{
148#if BITS_PER_LONG == 32
149
150 u64 result = ((u64) old) * ((u64) mult);
151 do_div(result, div);
152 return (unsigned long) result;
153
154#elif BITS_PER_LONG == 64
155
156 unsigned long result = old * ((u64) mult);
157 result /= div;
158 return result;
159
160#endif
161};
162
163/*********************************************************************
164 * CPUFREQ GOVERNORS *
165 *********************************************************************/
166
167#define CPUFREQ_GOV_START 1
168#define CPUFREQ_GOV_STOP 2
169#define CPUFREQ_GOV_LIMITS 3
170
171struct cpufreq_governor {
172 char name[CPUFREQ_NAME_LEN];
173 int (*governor) (struct cpufreq_policy *policy,
174 unsigned int event);
175 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
176 char *buf);
177 int (*store_setspeed) (struct cpufreq_policy *policy,
178 unsigned int freq);
179 unsigned int max_transition_latency; /* HW must be able to switch to
180 next freq faster than this value in nano secs or we
181 will fallback to performance governor */
182 struct list_head governor_list;
183 struct module *owner;
184};
185
186/*
187 * Pass a target to the cpufreq driver.
188 */
189extern int cpufreq_driver_target(struct cpufreq_policy *policy,
190 unsigned int target_freq,
191 unsigned int relation);
192extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
193 unsigned int target_freq,
194 unsigned int relation);
195
196
197extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
198 unsigned int cpu);
199
200int cpufreq_register_governor(struct cpufreq_governor *governor);
201void cpufreq_unregister_governor(struct cpufreq_governor *governor);
202
203
204/*********************************************************************
205 * CPUFREQ DRIVER INTERFACE *
206 *********************************************************************/
207
208#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
209#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
210
211struct freq_attr;
212
213struct cpufreq_driver {
214 struct module *owner;
215 char name[CPUFREQ_NAME_LEN];
216 u8 flags;
217
218 /* needed by all drivers */
219 int (*init) (struct cpufreq_policy *policy);
220 int (*verify) (struct cpufreq_policy *policy);
221
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);
227
228 /* should be defined, if possible */
229 unsigned int (*get) (unsigned int cpu);
230
231 /* optional */
232 unsigned int (*getavg) (struct cpufreq_policy *policy,
233 unsigned int cpu);
234 int (*bios_limit) (int cpu, unsigned int *limit);
235
236 int (*exit) (struct cpufreq_policy *policy);
237 int (*suspend) (struct cpufreq_policy *policy);
238 int (*resume) (struct cpufreq_policy *policy);
239 struct freq_attr **attr;
240};
241
242/* flags */
243
244#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
245 * all ->init() calls failed */
246#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
247 * "constants" aren't affected by
248 * frequency transitions */
249#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
250 * mismatches */
251
252int cpufreq_register_driver(struct cpufreq_driver *driver_data);
253int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
254
255
256void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
257
258
259static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
260{
261 if (policy->min < min)
262 policy->min = min;
263 if (policy->max < min)
264 policy->max = min;
265 if (policy->min > max)
266 policy->min = max;
267 if (policy->max > max)
268 policy->max = max;
269 if (policy->min > policy->max)
270 policy->min = policy->max;
271 return;
272}
273
274struct freq_attr {
275 struct attribute attr;
276 ssize_t (*show)(struct cpufreq_policy *, char *);
277 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
278};
279
280#define cpufreq_freq_attr_ro(_name) \
281static struct freq_attr _name = \
282__ATTR(_name, 0444, show_##_name, NULL)
283
284#define cpufreq_freq_attr_ro_perm(_name, _perm) \
285static struct freq_attr _name = \
286__ATTR(_name, _perm, show_##_name, NULL)
287
288#define cpufreq_freq_attr_rw(_name) \
289static struct freq_attr _name = \
290__ATTR(_name, 0644, show_##_name, store_##_name)
291
292struct global_attr {
293 struct attribute attr;
294 ssize_t (*show)(struct kobject *kobj,
295 struct attribute *attr, char *buf);
296 ssize_t (*store)(struct kobject *a, struct attribute *b,
297 const char *c, size_t count);
298};
299
300#define define_one_global_ro(_name) \
301static struct global_attr _name = \
302__ATTR(_name, 0444, show_##_name, NULL)
303
304#define define_one_global_rw(_name) \
305static struct global_attr _name = \
306__ATTR(_name, 0644, show_##_name, store_##_name)
307
308
309/*********************************************************************
310 * CPUFREQ 2.6. INTERFACE *
311 *********************************************************************/
312int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
313int cpufreq_update_policy(unsigned int cpu);
314
315#ifdef CONFIG_CPU_FREQ
316/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
317unsigned int cpufreq_get(unsigned int cpu);
318#else
319static inline unsigned int cpufreq_get(unsigned int cpu)
320{
321 return 0;
322}
323#endif
324
325/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
326#ifdef CONFIG_CPU_FREQ
327unsigned int cpufreq_quick_get(unsigned int cpu);
328unsigned int cpufreq_quick_get_max(unsigned int cpu);
329#else
330static inline unsigned int cpufreq_quick_get(unsigned int cpu)
331{
332 return 0;
333}
334static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
335{
336 return 0;
337}
338#endif
339
340
341/*********************************************************************
342 * CPUFREQ DEFAULT GOVERNOR *
343 *********************************************************************/
344
345
346/*
347 Performance governor is fallback governor if any other gov failed to
348 auto load due latency restrictions
349*/
350#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
351extern struct cpufreq_governor cpufreq_gov_performance;
352#endif
353#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
354#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
355#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
356extern struct cpufreq_governor cpufreq_gov_powersave;
357#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
358#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
359extern struct cpufreq_governor cpufreq_gov_userspace;
360#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
361#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
362extern struct cpufreq_governor cpufreq_gov_ondemand;
363#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
364#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
365extern struct cpufreq_governor cpufreq_gov_conservative;
366#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
367#endif
368
369
370/*********************************************************************
371 * FREQUENCY TABLE HELPERS *
372 *********************************************************************/
373
374#define CPUFREQ_ENTRY_INVALID ~0
375#define CPUFREQ_TABLE_END ~1
376
377struct cpufreq_frequency_table {
378 unsigned int index; /* any */
379 unsigned int frequency; /* kHz - doesn't need to be in ascending
380 * order */
381};
382
383int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
384 struct cpufreq_frequency_table *table);
385
386int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
387 struct cpufreq_frequency_table *table);
388
389int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
390 struct cpufreq_frequency_table *table,
391 unsigned int target_freq,
392 unsigned int relation,
393 unsigned int *index);
394
395/* the following 3 funtions are for cpufreq core use only */
396struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
397struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
398void cpufreq_cpu_put(struct cpufreq_policy *data);
399
400/* the following are really really optional */
401extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
402
403void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
404 unsigned int cpu);
405
406void cpufreq_frequency_table_put_attr(unsigned int cpu);
407
408
409#endif /* _LINUX_CPUFREQ_H */