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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 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
76};
77
78struct 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 */
83};
84
85struct cpufreq_policy {
86 cpumask_var_t cpus; /* CPUs requiring sw coordination */
87 cpumask_var_t related_cpus; /* CPUs with any coordination */
88 unsigned int shared_type; /* ANY or ALL affected CPUs
89 should set cpufreq */
90 unsigned int cpu; /* cpu nr of registered CPU */
91 struct cpufreq_cpuinfo cpuinfo;/* see above */
92
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 */
99
100 struct work_struct update; /* if update_policy() needs to be
101 * called, but you're in IRQ context */
102
103 struct cpufreq_real_policy user_policy;
104
105 struct kobject kobj;
106 struct completion kobj_unregister;
107};
108
109#define CPUFREQ_ADJUST (0)
110#define CPUFREQ_INCOMPATIBLE (1)
111#define CPUFREQ_NOTIFY (2)
112#define CPUFREQ_START (3)
113
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*/
118
119/******************** cpufreq transition notifiers *******************/
120
121#define CPUFREQ_PRECHANGE (0)
122#define CPUFREQ_POSTCHANGE (1)
123#define CPUFREQ_RESUMECHANGE (8)
124#define CPUFREQ_SUSPENDCHANGE (9)
125
126struct cpufreq_freqs {
127 unsigned int cpu; /* cpu nr */
128 unsigned int old;
129 unsigned int new;
130 u8 flags; /* flags of cpufreq_driver, see below. */
131};
132
133
134/**
135 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
136 * @old: old value
137 * @div: divisor
138 * @mult: multiplier
139 *
140 *
141 * new = old * mult / div
142 */
143static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
144{
145#if BITS_PER_LONG == 32
146
147 u64 result = ((u64) old) * ((u64) mult);
148 do_div(result, div);
149 return (unsigned long) result;
150
151#elif BITS_PER_LONG == 64
152
153 unsigned long result = old * ((u64) mult);
154 result /= div;
155 return result;
156
157#endif
158};
159
160/*********************************************************************
161 * CPUFREQ GOVERNORS *
162 *********************************************************************/
163
164#define CPUFREQ_GOV_START 1
165#define CPUFREQ_GOV_STOP 2
166#define CPUFREQ_GOV_LIMITS 3
167
168struct cpufreq_governor {
169 char name[CPUFREQ_NAME_LEN];
170 int (*governor) (struct cpufreq_policy *policy,
171 unsigned int event);
172 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
173 char *buf);
174 int (*store_setspeed) (struct cpufreq_policy *policy,
175 unsigned int freq);
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;
181};
182
183/* pass a target to the cpufreq driver
184 */
185extern int cpufreq_driver_target(struct cpufreq_policy *policy,
186 unsigned int target_freq,
187 unsigned int relation);
188extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
189 unsigned int target_freq,
190 unsigned int relation);
191
192
193extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
194 unsigned int cpu);
195
196int cpufreq_register_governor(struct cpufreq_governor *governor);
197void cpufreq_unregister_governor(struct cpufreq_governor *governor);
198
199int lock_policy_rwsem_read(int cpu);
200int lock_policy_rwsem_write(int cpu);
201void unlock_policy_rwsem_read(int cpu);
202void unlock_policy_rwsem_write(int cpu);
203
204
205/*********************************************************************
206 * CPUFREQ DRIVER INTERFACE *
207 *********************************************************************/
208
209#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
210#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
211
212struct freq_attr;
213
214struct cpufreq_driver {
215 struct module *owner;
216 char name[CPUFREQ_NAME_LEN];
217 u8 flags;
218
219 /* needed by all drivers */
220 int (*init) (struct cpufreq_policy *policy);
221 int (*verify) (struct cpufreq_policy *policy);
222
223 /* define one out of two */
224 int (*setpolicy) (struct cpufreq_policy *policy);
225 int (*target) (struct cpufreq_policy *policy,
226 unsigned int target_freq,
227 unsigned int relation);
228
229 /* should be defined, if possible */
230 unsigned int (*get) (unsigned int cpu);
231
232 /* optional */
233 unsigned int (*getavg) (struct cpufreq_policy *policy,
234 unsigned int cpu);
235 int (*bios_limit) (int cpu, unsigned int *limit);
236
237 int (*exit) (struct cpufreq_policy *policy);
238 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
239 int (*resume) (struct cpufreq_policy *policy);
240 struct freq_attr **attr;
241};
242
243/* flags */
244
245#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
246 * all ->init() calls failed */
247#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
248 * "constants" aren't affected by
249 * frequency transitions */
250#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
251 * mismatches */
252
253int cpufreq_register_driver(struct cpufreq_driver *driver_data);
254int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
255
256
257void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
258
259
260static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
261{
262 if (policy->min < min)
263 policy->min = min;
264 if (policy->max < min)
265 policy->max = min;
266 if (policy->min > max)
267 policy->min = max;
268 if (policy->max > max)
269 policy->max = max;
270 if (policy->min > policy->max)
271 policy->min = policy->max;
272 return;
273}
274
275struct freq_attr {
276 struct attribute attr;
277 ssize_t (*show)(struct cpufreq_policy *, char *);
278 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
279};
280
281struct global_attr {
282 struct attribute attr;
283 ssize_t (*show)(struct kobject *kobj,
284 struct attribute *attr, char *buf);
285 ssize_t (*store)(struct kobject *a, struct attribute *b,
286 const char *c, size_t count);
287};
288
289/*********************************************************************
290 * CPUFREQ 2.6. INTERFACE *
291 *********************************************************************/
292int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
293int cpufreq_update_policy(unsigned int cpu);
294
295#ifdef CONFIG_CPU_FREQ
296/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
297unsigned int cpufreq_get(unsigned int cpu);
298#else
299static inline unsigned int cpufreq_get(unsigned int cpu)
300{
301 return 0;
302}
303#endif
304
305/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
306#ifdef CONFIG_CPU_FREQ
307unsigned int cpufreq_quick_get(unsigned int cpu);
308#else
309static inline unsigned int cpufreq_quick_get(unsigned int cpu)
310{
311 return 0;
312}
313#endif
314
315
316/*********************************************************************
317 * CPUFREQ DEFAULT GOVERNOR *
318 *********************************************************************/
319
320
321/*
322 Performance governor is fallback governor if any other gov failed to
323 auto load due latency restrictions
324*/
325#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
326extern struct cpufreq_governor cpufreq_gov_performance;
327#endif
328#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
329#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
330#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
331extern struct cpufreq_governor cpufreq_gov_powersave;
332#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
333#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
334extern struct cpufreq_governor cpufreq_gov_userspace;
335#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
336#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
337extern struct cpufreq_governor cpufreq_gov_ondemand;
338#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
339#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
340extern struct cpufreq_governor cpufreq_gov_conservative;
341#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
342#endif
343
344
345/*********************************************************************
346 * FREQUENCY TABLE HELPERS *
347 *********************************************************************/
348
349#define CPUFREQ_ENTRY_INVALID ~0
350#define CPUFREQ_TABLE_END ~1
351
352struct cpufreq_frequency_table {
353 unsigned int index; /* any */
354 unsigned int frequency; /* kHz - doesn't need to be in ascending
355 * order */
356};
357
358int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
359 struct cpufreq_frequency_table *table);
360
361int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
362 struct cpufreq_frequency_table *table);
363
364int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
365 struct cpufreq_frequency_table *table,
366 unsigned int target_freq,
367 unsigned int relation,
368 unsigned int *index);
369
370/* the following 3 funtions are for cpufreq core use only */
371struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
372struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
373void cpufreq_cpu_put (struct cpufreq_policy *data);
374
375/* the following are really really optional */
376extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
377
378void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
379 unsigned int cpu);
380
381void cpufreq_frequency_table_put_attr(unsigned int cpu);
382
383
384/*********************************************************************
385 * UNIFIED DEBUG HELPERS *
386 *********************************************************************/
387
388#define CPUFREQ_DEBUG_CORE 1
389#define CPUFREQ_DEBUG_DRIVER 2
390#define CPUFREQ_DEBUG_GOVERNOR 4
391
392#ifdef CONFIG_CPU_FREQ_DEBUG
393
394extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
395 const char *fmt, ...);
396
397#else
398
399#define cpufreq_debug_printk(msg...) do { } while(0)
400
401#endif /* CONFIG_CPU_FREQ_DEBUG */
402
403#endif /* _LINUX_CPUFREQ_H */