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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#define CPUFREQ_ETERNAL (-1)
69struct cpufreq_cpuinfo {
70 unsigned int max_freq;
71 unsigned int min_freq;
72 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
73};
74
75struct cpufreq_real_policy {
76 unsigned int min; /* in kHz */
77 unsigned int max; /* in kHz */
78 unsigned int policy; /* see above */
79 struct cpufreq_governor *governor; /* see below */
80};
81
82struct cpufreq_policy {
83 cpumask_t cpus; /* CPUs requiring sw coordination */
84 cpumask_t related_cpus; /* CPUs with any coordination */
85 unsigned int shared_type; /* ANY or ALL affected CPUs
86 should set cpufreq */
87 unsigned int cpu; /* cpu nr of registered CPU */
88 struct cpufreq_cpuinfo cpuinfo;/* see above */
89
90 unsigned int min; /* in kHz */
91 unsigned int max; /* in kHz */
92 unsigned int cur; /* in kHz, only needed if cpufreq
93 * governors are used */
94 unsigned int policy; /* see above */
95 struct cpufreq_governor *governor; /* see below */
96
97 struct work_struct update; /* if update_policy() needs to be
98 * called, but you're in IRQ context */
99
100 struct cpufreq_real_policy user_policy;
101
102 struct kobject kobj;
103 struct completion kobj_unregister;
104};
105
106#define CPUFREQ_ADJUST (0)
107#define CPUFREQ_INCOMPATIBLE (1)
108#define CPUFREQ_NOTIFY (2)
109
110#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
111#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
112#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
113#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
114
115/******************** cpufreq transition notifiers *******************/
116
117#define CPUFREQ_PRECHANGE (0)
118#define CPUFREQ_POSTCHANGE (1)
119#define CPUFREQ_RESUMECHANGE (8)
120#define CPUFREQ_SUSPENDCHANGE (9)
121
122struct cpufreq_freqs {
123 unsigned int cpu; /* cpu nr */
124 unsigned int old;
125 unsigned int new;
126 u8 flags; /* flags of cpufreq_driver, see below. */
127};
128
129
130/**
131 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
132 * @old: old value
133 * @div: divisor
134 * @mult: multiplier
135 *
136 *
137 * new = old * mult / div
138 */
139static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
140{
141#if BITS_PER_LONG == 32
142
143 u64 result = ((u64) old) * ((u64) mult);
144 do_div(result, div);
145 return (unsigned long) result;
146
147#elif BITS_PER_LONG == 64
148
149 unsigned long result = old * ((u64) mult);
150 result /= div;
151 return result;
152
153#endif
154};
155
156/*********************************************************************
157 * CPUFREQ GOVERNORS *
158 *********************************************************************/
159
160#define CPUFREQ_GOV_START 1
161#define CPUFREQ_GOV_STOP 2
162#define CPUFREQ_GOV_LIMITS 3
163
164struct cpufreq_governor {
165 char name[CPUFREQ_NAME_LEN];
166 int (*governor) (struct cpufreq_policy *policy,
167 unsigned int event);
168 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
169 char *buf);
170 int (*store_setspeed) (struct cpufreq_policy *policy,
171 unsigned int freq);
172 unsigned int max_transition_latency; /* HW must be able to switch to
173 next freq faster than this value in nano secs or we
174 will fallback to performance governor */
175 struct list_head governor_list;
176 struct module *owner;
177};
178
179/* pass a target to the cpufreq driver
180 */
181extern int cpufreq_driver_target(struct cpufreq_policy *policy,
182 unsigned int target_freq,
183 unsigned int relation);
184extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
185 unsigned int target_freq,
186 unsigned int relation);
187
188
189extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy);
190
191int cpufreq_register_governor(struct cpufreq_governor *governor);
192void cpufreq_unregister_governor(struct cpufreq_governor *governor);
193
194int lock_policy_rwsem_read(int cpu);
195int lock_policy_rwsem_write(int cpu);
196void unlock_policy_rwsem_read(int cpu);
197void unlock_policy_rwsem_write(int cpu);
198
199
200/*********************************************************************
201 * CPUFREQ DRIVER INTERFACE *
202 *********************************************************************/
203
204#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
205#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
206
207struct freq_attr;
208
209struct cpufreq_driver {
210 struct module *owner;
211 char name[CPUFREQ_NAME_LEN];
212 u8 flags;
213
214 /* needed by all drivers */
215 int (*init) (struct cpufreq_policy *policy);
216 int (*verify) (struct cpufreq_policy *policy);
217
218 /* define one out of two */
219 int (*setpolicy) (struct cpufreq_policy *policy);
220 int (*target) (struct cpufreq_policy *policy,
221 unsigned int target_freq,
222 unsigned int relation);
223
224 /* should be defined, if possible */
225 unsigned int (*get) (unsigned int cpu);
226
227 /* optional */
228 unsigned int (*getavg) (unsigned int cpu);
229 int (*exit) (struct cpufreq_policy *policy);
230 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
231 int (*resume) (struct cpufreq_policy *policy);
232 struct freq_attr **attr;
233};
234
235/* flags */
236
237#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
238 * all ->init() calls failed */
239#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
240 * "constants" aren't affected by
241 * frequency transitions */
242#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
243 * mismatches */
244
245int cpufreq_register_driver(struct cpufreq_driver *driver_data);
246int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
247
248
249void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
250
251
252static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
253{
254 if (policy->min < min)
255 policy->min = min;
256 if (policy->max < min)
257 policy->max = min;
258 if (policy->min > max)
259 policy->min = max;
260 if (policy->max > max)
261 policy->max = max;
262 if (policy->min > policy->max)
263 policy->min = policy->max;
264 return;
265}
266
267struct freq_attr {
268 struct attribute attr;
269 ssize_t (*show)(struct cpufreq_policy *, char *);
270 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
271};
272
273
274/*********************************************************************
275 * CPUFREQ 2.6. INTERFACE *
276 *********************************************************************/
277int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
278int cpufreq_update_policy(unsigned int cpu);
279
280/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
281unsigned int cpufreq_get(unsigned int cpu);
282
283/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
284#ifdef CONFIG_CPU_FREQ
285unsigned int cpufreq_quick_get(unsigned int cpu);
286#else
287static inline unsigned int cpufreq_quick_get(unsigned int cpu)
288{
289 return 0;
290}
291#endif
292
293
294/*********************************************************************
295 * CPUFREQ DEFAULT GOVERNOR *
296 *********************************************************************/
297
298
299/*
300 Performance governor is fallback governor if any other gov failed to
301 auto load due latency restrictions
302*/
303#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
304extern struct cpufreq_governor cpufreq_gov_performance;
305#endif
306#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
307#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
308#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
309extern struct cpufreq_governor cpufreq_gov_powersave;
310#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
311#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
312extern struct cpufreq_governor cpufreq_gov_userspace;
313#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
314#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
315extern struct cpufreq_governor cpufreq_gov_ondemand;
316#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
317#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
318extern struct cpufreq_governor cpufreq_gov_conservative;
319#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
320#endif
321
322
323/*********************************************************************
324 * FREQUENCY TABLE HELPERS *
325 *********************************************************************/
326
327#define CPUFREQ_ENTRY_INVALID ~0
328#define CPUFREQ_TABLE_END ~1
329
330struct cpufreq_frequency_table {
331 unsigned int index; /* any */
332 unsigned int frequency; /* kHz - doesn't need to be in ascending
333 * order */
334};
335
336int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
337 struct cpufreq_frequency_table *table);
338
339int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
340 struct cpufreq_frequency_table *table);
341
342int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
343 struct cpufreq_frequency_table *table,
344 unsigned int target_freq,
345 unsigned int relation,
346 unsigned int *index);
347
348/* the following 3 funtions are for cpufreq core use only */
349struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
350struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
351void cpufreq_cpu_put (struct cpufreq_policy *data);
352
353/* the following are really really optional */
354extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
355
356void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
357 unsigned int cpu);
358
359void cpufreq_frequency_table_put_attr(unsigned int cpu);
360
361
362/*********************************************************************
363 * UNIFIED DEBUG HELPERS *
364 *********************************************************************/
365
366#define CPUFREQ_DEBUG_CORE 1
367#define CPUFREQ_DEBUG_DRIVER 2
368#define CPUFREQ_DEBUG_GOVERNOR 4
369
370#ifdef CONFIG_CPU_FREQ_DEBUG
371
372extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
373 const char *fmt, ...);
374
375#else
376
377#define cpufreq_debug_printk(msg...) do { } while(0)
378
379#endif /* CONFIG_CPU_FREQ_DEBUG */
380
381#endif /* _LINUX_CPUFREQ_H */