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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/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>
24
25#define CPUFREQ_NAME_LEN 16
26
27
28/*********************************************************************
29 * CPUFREQ NOTIFIER INTERFACE *
30 *********************************************************************/
31
32#define CPUFREQ_TRANSITION_NOTIFIER (0)
33#define CPUFREQ_POLICY_NOTIFIER (1)
34
35#ifdef CONFIG_CPU_FREQ
36int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
37int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
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}
49#endif /* CONFIG_CPU_FREQ */
50
51/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
52 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
53 * two generic policies are available:
54 */
55
56#define CPUFREQ_POLICY_POWERSAVE (1)
57#define CPUFREQ_POLICY_PERFORMANCE (2)
58
59/* Frequency values here are CPU kHz so that hardware which doesn't run
60 * with some frequencies can complain without having to guess what per
61 * cent / per mille means.
62 * Maximum transition latency is in nanoseconds - if it's unknown,
63 * CPUFREQ_ETERNAL shall be used.
64 */
65
66struct cpufreq_governor;
67
68/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
69extern struct kobject *cpufreq_global_kobject;
70
71#define CPUFREQ_ETERNAL (-1)
72struct cpufreq_cpuinfo {
73 unsigned int max_freq;
74 unsigned int min_freq;
75
76 /* in 10^(-9) s = nanoseconds */
77 unsigned int transition_latency;
78};
79
80struct cpufreq_real_policy {
81 unsigned int min; /* in kHz */
82 unsigned int max; /* in kHz */
83 unsigned int policy; /* see above */
84 struct cpufreq_governor *governor; /* see below */
85};
86
87struct cpufreq_policy {
88 cpumask_var_t cpus; /* CPUs requiring sw coordination */
89 cpumask_var_t related_cpus; /* CPUs with any coordination */
90 unsigned int shared_type; /* ANY or ALL affected CPUs
91 should set cpufreq */
92 unsigned int cpu; /* cpu nr of registered CPU */
93 struct cpufreq_cpuinfo cpuinfo;/* see above */
94
95 unsigned int min; /* in kHz */
96 unsigned int max; /* in kHz */
97 unsigned int cur; /* in kHz, only needed if cpufreq
98 * governors are used */
99 unsigned int policy; /* see above */
100 struct cpufreq_governor *governor; /* see below */
101
102 struct work_struct update; /* if update_policy() needs to be
103 * called, but you're in IRQ context */
104
105 struct cpufreq_real_policy user_policy;
106
107 struct kobject kobj;
108 struct completion kobj_unregister;
109};
110
111#define CPUFREQ_ADJUST (0)
112#define CPUFREQ_INCOMPATIBLE (1)
113#define CPUFREQ_NOTIFY (2)
114#define CPUFREQ_START (3)
115
116#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
117#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
118#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
119#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
120
121/******************** cpufreq transition notifiers *******************/
122
123#define CPUFREQ_PRECHANGE (0)
124#define CPUFREQ_POSTCHANGE (1)
125#define CPUFREQ_RESUMECHANGE (8)
126#define CPUFREQ_SUSPENDCHANGE (9)
127
128struct cpufreq_freqs {
129 unsigned int cpu; /* cpu nr */
130 unsigned int old;
131 unsigned int new;
132 u8 flags; /* flags of cpufreq_driver, see below. */
133};
134
135
136/**
137 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
138 * @old: old value
139 * @div: divisor
140 * @mult: multiplier
141 *
142 *
143 * new = old * mult / div
144 */
145static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
146{
147#if BITS_PER_LONG == 32
148
149 u64 result = ((u64) old) * ((u64) mult);
150 do_div(result, div);
151 return (unsigned long) result;
152
153#elif BITS_PER_LONG == 64
154
155 unsigned long result = old * ((u64) mult);
156 result /= div;
157 return result;
158
159#endif
160};
161
162/*********************************************************************
163 * CPUFREQ GOVERNORS *
164 *********************************************************************/
165
166#define CPUFREQ_GOV_START 1
167#define CPUFREQ_GOV_STOP 2
168#define CPUFREQ_GOV_LIMITS 3
169
170struct cpufreq_governor {
171 char name[CPUFREQ_NAME_LEN];
172 int (*governor) (struct cpufreq_policy *policy,
173 unsigned int event);
174 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
175 char *buf);
176 int (*store_setspeed) (struct cpufreq_policy *policy,
177 unsigned int freq);
178 unsigned int max_transition_latency; /* HW must be able to switch to
179 next freq faster than this value in nano secs or we
180 will fallback to performance governor */
181 struct list_head governor_list;
182 struct module *owner;
183};
184
185/*
186 * Pass a target to the cpufreq driver.
187 */
188extern int cpufreq_driver_target(struct cpufreq_policy *policy,
189 unsigned int target_freq,
190 unsigned int relation);
191extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
192 unsigned int target_freq,
193 unsigned int relation);
194
195
196extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
197 unsigned int cpu);
198
199int cpufreq_register_governor(struct cpufreq_governor *governor);
200void cpufreq_unregister_governor(struct cpufreq_governor *governor);
201
202
203/*********************************************************************
204 * CPUFREQ DRIVER INTERFACE *
205 *********************************************************************/
206
207#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
208#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
209
210struct freq_attr;
211
212struct cpufreq_driver {
213 struct module *owner;
214 char name[CPUFREQ_NAME_LEN];
215 u8 flags;
216
217 /* needed by all drivers */
218 int (*init) (struct cpufreq_policy *policy);
219 int (*verify) (struct cpufreq_policy *policy);
220
221 /* define one out of two */
222 int (*setpolicy) (struct cpufreq_policy *policy);
223 int (*target) (struct cpufreq_policy *policy,
224 unsigned int target_freq,
225 unsigned int relation);
226
227 /* should be defined, if possible */
228 unsigned int (*get) (unsigned int cpu);
229
230 /* optional */
231 unsigned int (*getavg) (struct cpufreq_policy *policy,
232 unsigned int cpu);
233 int (*bios_limit) (int cpu, unsigned int *limit);
234
235 int (*exit) (struct cpufreq_policy *policy);
236 int (*suspend) (struct cpufreq_policy *policy);
237 int (*resume) (struct cpufreq_policy *policy);
238 struct freq_attr **attr;
239};
240
241/* flags */
242
243#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
244 * all ->init() calls failed */
245#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
246 * "constants" aren't affected by
247 * frequency transitions */
248#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
249 * mismatches */
250
251int cpufreq_register_driver(struct cpufreq_driver *driver_data);
252int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
253
254
255void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
256
257
258static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
259{
260 if (policy->min < min)
261 policy->min = min;
262 if (policy->max < min)
263 policy->max = min;
264 if (policy->min > max)
265 policy->min = max;
266 if (policy->max > max)
267 policy->max = max;
268 if (policy->min > policy->max)
269 policy->min = policy->max;
270 return;
271}
272
273struct freq_attr {
274 struct attribute attr;
275 ssize_t (*show)(struct cpufreq_policy *, char *);
276 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
277};
278
279#define cpufreq_freq_attr_ro(_name) \
280static struct freq_attr _name = \
281__ATTR(_name, 0444, show_##_name, NULL)
282
283#define cpufreq_freq_attr_ro_perm(_name, _perm) \
284static struct freq_attr _name = \
285__ATTR(_name, _perm, show_##_name, NULL)
286
287#define cpufreq_freq_attr_rw(_name) \
288static struct freq_attr _name = \
289__ATTR(_name, 0644, show_##_name, store_##_name)
290
291struct global_attr {
292 struct attribute attr;
293 ssize_t (*show)(struct kobject *kobj,
294 struct attribute *attr, char *buf);
295 ssize_t (*store)(struct kobject *a, struct attribute *b,
296 const char *c, size_t count);
297};
298
299#define define_one_global_ro(_name) \
300static struct global_attr _name = \
301__ATTR(_name, 0444, show_##_name, NULL)
302
303#define define_one_global_rw(_name) \
304static struct global_attr _name = \
305__ATTR(_name, 0644, show_##_name, store_##_name)
306
307
308/*********************************************************************
309 * CPUFREQ 2.6. INTERFACE *
310 *********************************************************************/
311int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
312int cpufreq_update_policy(unsigned int cpu);
313
314#ifdef CONFIG_CPU_FREQ
315/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
316unsigned int cpufreq_get(unsigned int cpu);
317#else
318static inline unsigned int cpufreq_get(unsigned int cpu)
319{
320 return 0;
321}
322#endif
323
324/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
325#ifdef CONFIG_CPU_FREQ
326unsigned int cpufreq_quick_get(unsigned int cpu);
327#else
328static inline unsigned int cpufreq_quick_get(unsigned int cpu)
329{
330 return 0;
331}
332#endif
333
334
335/*********************************************************************
336 * CPUFREQ DEFAULT GOVERNOR *
337 *********************************************************************/
338
339
340/*
341 Performance governor is fallback governor if any other gov failed to
342 auto load due latency restrictions
343*/
344#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
345extern struct cpufreq_governor cpufreq_gov_performance;
346#endif
347#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
348#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
349#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
350extern struct cpufreq_governor cpufreq_gov_powersave;
351#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
352#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
353extern struct cpufreq_governor cpufreq_gov_userspace;
354#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
355#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
356extern struct cpufreq_governor cpufreq_gov_ondemand;
357#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
358#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
359extern struct cpufreq_governor cpufreq_gov_conservative;
360#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
361#endif
362
363
364/*********************************************************************
365 * FREQUENCY TABLE HELPERS *
366 *********************************************************************/
367
368#define CPUFREQ_ENTRY_INVALID ~0
369#define CPUFREQ_TABLE_END ~1
370
371struct cpufreq_frequency_table {
372 unsigned int index; /* any */
373 unsigned int frequency; /* kHz - doesn't need to be in ascending
374 * order */
375};
376
377int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
378 struct cpufreq_frequency_table *table);
379
380int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
381 struct cpufreq_frequency_table *table);
382
383int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
384 struct cpufreq_frequency_table *table,
385 unsigned int target_freq,
386 unsigned int relation,
387 unsigned int *index);
388
389/* the following 3 funtions are for cpufreq core use only */
390struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
391struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
392void cpufreq_cpu_put(struct cpufreq_policy *data);
393
394/* the following are really really optional */
395extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
396
397void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
398 unsigned int cpu);
399
400void cpufreq_frequency_table_put_attr(unsigned int cpu);
401
402
403#endif /* _LINUX_CPUFREQ_H */