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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 <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>
24
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)
28
29
30/*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
33
34#define CPUFREQ_TRANSITION_NOTIFIER (0)
35#define CPUFREQ_POLICY_NOTIFIER (1)
36
37#ifdef CONFIG_CPU_FREQ
38int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
39int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
40extern void disable_cpufreq(void);
41#else /* CONFIG_CPU_FREQ */
42static inline int cpufreq_register_notifier(struct notifier_block *nb,
43 unsigned int list)
44{
45 return 0;
46}
47static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
48 unsigned int list)
49{
50 return 0;
51}
52static inline void disable_cpufreq(void) { }
53#endif /* CONFIG_CPU_FREQ */
54
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:
58 */
59
60#define CPUFREQ_POLICY_POWERSAVE (1)
61#define CPUFREQ_POLICY_PERFORMANCE (2)
62
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.
68 */
69
70struct cpufreq_governor;
71
72/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
73extern struct kobject *cpufreq_global_kobject;
74
75#define CPUFREQ_ETERNAL (-1)
76struct cpufreq_cpuinfo {
77 unsigned int max_freq;
78 unsigned int min_freq;
79
80 /* in 10^(-9) s = nanoseconds */
81 unsigned int transition_latency;
82};
83
84struct 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 */
89};
90
91struct cpufreq_policy {
92 cpumask_var_t cpus; /* CPUs requiring sw coordination */
93 cpumask_var_t related_cpus; /* CPUs with any coordination */
94 unsigned int shared_type; /* ANY or ALL affected CPUs
95 should set cpufreq */
96 unsigned int cpu; /* cpu nr of registered CPU */
97 struct cpufreq_cpuinfo cpuinfo;/* see above */
98
99 unsigned int min; /* in kHz */
100 unsigned int max; /* in kHz */
101 unsigned int cur; /* in kHz, only needed if cpufreq
102 * governors are used */
103 unsigned int policy; /* see above */
104 struct cpufreq_governor *governor; /* see below */
105
106 struct work_struct update; /* if update_policy() needs to be
107 * called, but you're in IRQ context */
108
109 struct cpufreq_real_policy user_policy;
110
111 struct kobject kobj;
112 struct completion kobj_unregister;
113};
114
115#define CPUFREQ_ADJUST (0)
116#define CPUFREQ_INCOMPATIBLE (1)
117#define CPUFREQ_NOTIFY (2)
118#define CPUFREQ_START (3)
119
120#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
121#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
122#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
123#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
124
125/******************** cpufreq transition notifiers *******************/
126
127#define CPUFREQ_PRECHANGE (0)
128#define CPUFREQ_POSTCHANGE (1)
129#define CPUFREQ_RESUMECHANGE (8)
130#define CPUFREQ_SUSPENDCHANGE (9)
131
132struct cpufreq_freqs {
133 unsigned int cpu; /* cpu nr */
134 unsigned int old;
135 unsigned int new;
136 u8 flags; /* flags of cpufreq_driver, see below. */
137};
138
139
140/**
141 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
142 * @old: old value
143 * @div: divisor
144 * @mult: multiplier
145 *
146 *
147 * new = old * mult / div
148 */
149static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
150{
151#if BITS_PER_LONG == 32
152
153 u64 result = ((u64) old) * ((u64) mult);
154 do_div(result, div);
155 return (unsigned long) result;
156
157#elif BITS_PER_LONG == 64
158
159 unsigned long result = old * ((u64) mult);
160 result /= div;
161 return result;
162
163#endif
164};
165
166/*********************************************************************
167 * CPUFREQ GOVERNORS *
168 *********************************************************************/
169
170#define CPUFREQ_GOV_START 1
171#define CPUFREQ_GOV_STOP 2
172#define CPUFREQ_GOV_LIMITS 3
173
174struct cpufreq_governor {
175 char name[CPUFREQ_NAME_LEN];
176 int (*governor) (struct cpufreq_policy *policy,
177 unsigned int event);
178 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
179 char *buf);
180 int (*store_setspeed) (struct cpufreq_policy *policy,
181 unsigned int freq);
182 unsigned int max_transition_latency; /* HW must be able to switch to
183 next freq faster than this value in nano secs or we
184 will fallback to performance governor */
185 struct list_head governor_list;
186 struct module *owner;
187};
188
189/*
190 * Pass a target to the cpufreq driver.
191 */
192extern int cpufreq_driver_target(struct cpufreq_policy *policy,
193 unsigned int target_freq,
194 unsigned int relation);
195extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
196 unsigned int target_freq,
197 unsigned int relation);
198
199
200extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
201 unsigned int cpu);
202
203int cpufreq_register_governor(struct cpufreq_governor *governor);
204void cpufreq_unregister_governor(struct cpufreq_governor *governor);
205
206
207/*********************************************************************
208 * CPUFREQ DRIVER INTERFACE *
209 *********************************************************************/
210
211#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
212#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
213
214struct freq_attr;
215
216struct cpufreq_driver {
217 struct module *owner;
218 char name[CPUFREQ_NAME_LEN];
219 u8 flags;
220
221 /* needed by all drivers */
222 int (*init) (struct cpufreq_policy *policy);
223 int (*verify) (struct cpufreq_policy *policy);
224
225 /* define one out of two */
226 int (*setpolicy) (struct cpufreq_policy *policy);
227 int (*target) (struct cpufreq_policy *policy,
228 unsigned int target_freq,
229 unsigned int relation);
230
231 /* should be defined, if possible */
232 unsigned int (*get) (unsigned int cpu);
233
234 /* optional */
235 unsigned int (*getavg) (struct cpufreq_policy *policy,
236 unsigned int cpu);
237 int (*bios_limit) (int cpu, unsigned int *limit);
238
239 int (*exit) (struct cpufreq_policy *policy);
240 int (*suspend) (struct cpufreq_policy *policy);
241 int (*resume) (struct cpufreq_policy *policy);
242 struct freq_attr **attr;
243};
244
245/* flags */
246
247#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
248 * all ->init() calls failed */
249#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
250 * "constants" aren't affected by
251 * frequency transitions */
252#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
253 * mismatches */
254
255int cpufreq_register_driver(struct cpufreq_driver *driver_data);
256int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
257
258
259void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
260
261
262static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
263{
264 if (policy->min < min)
265 policy->min = min;
266 if (policy->max < min)
267 policy->max = min;
268 if (policy->min > max)
269 policy->min = max;
270 if (policy->max > max)
271 policy->max = max;
272 if (policy->min > policy->max)
273 policy->min = policy->max;
274 return;
275}
276
277struct freq_attr {
278 struct attribute attr;
279 ssize_t (*show)(struct cpufreq_policy *, char *);
280 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
281};
282
283#define cpufreq_freq_attr_ro(_name) \
284static struct freq_attr _name = \
285__ATTR(_name, 0444, show_##_name, NULL)
286
287#define cpufreq_freq_attr_ro_perm(_name, _perm) \
288static struct freq_attr _name = \
289__ATTR(_name, _perm, show_##_name, NULL)
290
291#define cpufreq_freq_attr_rw(_name) \
292static struct freq_attr _name = \
293__ATTR(_name, 0644, show_##_name, store_##_name)
294
295struct global_attr {
296 struct attribute attr;
297 ssize_t (*show)(struct kobject *kobj,
298 struct attribute *attr, char *buf);
299 ssize_t (*store)(struct kobject *a, struct attribute *b,
300 const char *c, size_t count);
301};
302
303#define define_one_global_ro(_name) \
304static struct global_attr _name = \
305__ATTR(_name, 0444, show_##_name, NULL)
306
307#define define_one_global_rw(_name) \
308static struct global_attr _name = \
309__ATTR(_name, 0644, show_##_name, store_##_name)
310
311
312/*********************************************************************
313 * CPUFREQ 2.6. INTERFACE *
314 *********************************************************************/
315int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
316int cpufreq_update_policy(unsigned int cpu);
317
318#ifdef CONFIG_CPU_FREQ
319/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
320unsigned int cpufreq_get(unsigned int cpu);
321#else
322static inline unsigned int cpufreq_get(unsigned int cpu)
323{
324 return 0;
325}
326#endif
327
328/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
329#ifdef CONFIG_CPU_FREQ
330unsigned int cpufreq_quick_get(unsigned int cpu);
331unsigned int cpufreq_quick_get_max(unsigned int cpu);
332#else
333static inline unsigned int cpufreq_quick_get(unsigned int cpu)
334{
335 return 0;
336}
337static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
338{
339 return 0;
340}
341#endif
342
343
344/*********************************************************************
345 * CPUFREQ DEFAULT GOVERNOR *
346 *********************************************************************/
347
348
349/*
350 Performance governor is fallback governor if any other gov failed to
351 auto load due latency restrictions
352*/
353#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
354extern struct cpufreq_governor cpufreq_gov_performance;
355#endif
356#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
357#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
358#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
359extern struct cpufreq_governor cpufreq_gov_powersave;
360#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
361#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
362extern struct cpufreq_governor cpufreq_gov_userspace;
363#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
364#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
365extern struct cpufreq_governor cpufreq_gov_ondemand;
366#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
367#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
368extern struct cpufreq_governor cpufreq_gov_conservative;
369#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
370#endif
371
372
373/*********************************************************************
374 * FREQUENCY TABLE HELPERS *
375 *********************************************************************/
376
377#define CPUFREQ_ENTRY_INVALID ~0
378#define CPUFREQ_TABLE_END ~1
379
380struct cpufreq_frequency_table {
381 unsigned int index; /* any */
382 unsigned int frequency; /* kHz - doesn't need to be in ascending
383 * order */
384};
385
386int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
387 struct cpufreq_frequency_table *table);
388
389int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
390 struct cpufreq_frequency_table *table);
391
392int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
393 struct cpufreq_frequency_table *table,
394 unsigned int target_freq,
395 unsigned int relation,
396 unsigned int *index);
397
398/* the following 3 funtions are for cpufreq core use only */
399struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
400struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
401void cpufreq_cpu_put(struct cpufreq_policy *data);
402
403/* the following are really really optional */
404extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
405
406void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
407 unsigned int cpu);
408
409void cpufreq_frequency_table_put_attr(unsigned int cpu);
410#endif /* _LINUX_CPUFREQ_H */