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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_var_t cpus; /* CPUs requiring sw coordination */
84 cpumask_var_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#define CPUFREQ_START (3)
110
111#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
112#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
113#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
114#define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
115
116/******************** cpufreq transition notifiers *******************/
117
118#define CPUFREQ_PRECHANGE (0)
119#define CPUFREQ_POSTCHANGE (1)
120#define CPUFREQ_RESUMECHANGE (8)
121#define CPUFREQ_SUSPENDCHANGE (9)
122
123struct cpufreq_freqs {
124 unsigned int cpu; /* cpu nr */
125 unsigned int old;
126 unsigned int new;
127 u8 flags; /* flags of cpufreq_driver, see below. */
128};
129
130
131/**
132 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
133 * @old: old value
134 * @div: divisor
135 * @mult: multiplier
136 *
137 *
138 * new = old * mult / div
139 */
140static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
141{
142#if BITS_PER_LONG == 32
143
144 u64 result = ((u64) old) * ((u64) mult);
145 do_div(result, div);
146 return (unsigned long) result;
147
148#elif BITS_PER_LONG == 64
149
150 unsigned long result = old * ((u64) mult);
151 result /= div;
152 return result;
153
154#endif
155};
156
157/*********************************************************************
158 * CPUFREQ GOVERNORS *
159 *********************************************************************/
160
161#define CPUFREQ_GOV_START 1
162#define CPUFREQ_GOV_STOP 2
163#define CPUFREQ_GOV_LIMITS 3
164
165struct cpufreq_governor {
166 char name[CPUFREQ_NAME_LEN];
167 int (*governor) (struct cpufreq_policy *policy,
168 unsigned int event);
169 ssize_t (*show_setspeed) (struct cpufreq_policy *policy,
170 char *buf);
171 int (*store_setspeed) (struct cpufreq_policy *policy,
172 unsigned int freq);
173 unsigned int max_transition_latency; /* HW must be able to switch to
174 next freq faster than this value in nano secs or we
175 will fallback to performance governor */
176 struct list_head governor_list;
177 struct module *owner;
178};
179
180/* pass a target to the cpufreq driver
181 */
182extern int cpufreq_driver_target(struct cpufreq_policy *policy,
183 unsigned int target_freq,
184 unsigned int relation);
185extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
186 unsigned int target_freq,
187 unsigned int relation);
188
189
190extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
191 unsigned int cpu);
192
193int cpufreq_register_governor(struct cpufreq_governor *governor);
194void cpufreq_unregister_governor(struct cpufreq_governor *governor);
195
196int lock_policy_rwsem_read(int cpu);
197int lock_policy_rwsem_write(int cpu);
198void unlock_policy_rwsem_read(int cpu);
199void unlock_policy_rwsem_write(int cpu);
200
201
202/*********************************************************************
203 * CPUFREQ DRIVER INTERFACE *
204 *********************************************************************/
205
206#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
207#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
208
209struct freq_attr;
210
211struct cpufreq_driver {
212 struct module *owner;
213 char name[CPUFREQ_NAME_LEN];
214 u8 flags;
215
216 /* needed by all drivers */
217 int (*init) (struct cpufreq_policy *policy);
218 int (*verify) (struct cpufreq_policy *policy);
219
220 /* define one out of two */
221 int (*setpolicy) (struct cpufreq_policy *policy);
222 int (*target) (struct cpufreq_policy *policy,
223 unsigned int target_freq,
224 unsigned int relation);
225
226 /* should be defined, if possible */
227 unsigned int (*get) (unsigned int cpu);
228
229 /* optional */
230 unsigned int (*getavg) (struct cpufreq_policy *policy,
231 unsigned int cpu);
232
233 int (*exit) (struct cpufreq_policy *policy);
234 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
235 int (*resume) (struct cpufreq_policy *policy);
236 struct freq_attr **attr;
237};
238
239/* flags */
240
241#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
242 * all ->init() calls failed */
243#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
244 * "constants" aren't affected by
245 * frequency transitions */
246#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
247 * mismatches */
248
249int cpufreq_register_driver(struct cpufreq_driver *driver_data);
250int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
251
252
253void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
254
255
256static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
257{
258 if (policy->min < min)
259 policy->min = min;
260 if (policy->max < min)
261 policy->max = min;
262 if (policy->min > max)
263 policy->min = max;
264 if (policy->max > max)
265 policy->max = max;
266 if (policy->min > policy->max)
267 policy->min = policy->max;
268 return;
269}
270
271struct freq_attr {
272 struct attribute attr;
273 ssize_t (*show)(struct cpufreq_policy *, char *);
274 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
275};
276
277
278/*********************************************************************
279 * CPUFREQ 2.6. INTERFACE *
280 *********************************************************************/
281int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
282int cpufreq_update_policy(unsigned int cpu);
283
284/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
285unsigned int cpufreq_get(unsigned int cpu);
286
287/* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
288#ifdef CONFIG_CPU_FREQ
289unsigned int cpufreq_quick_get(unsigned int cpu);
290#else
291static inline unsigned int cpufreq_quick_get(unsigned int cpu)
292{
293 return 0;
294}
295#endif
296
297
298/*********************************************************************
299 * CPUFREQ DEFAULT GOVERNOR *
300 *********************************************************************/
301
302
303/*
304 Performance governor is fallback governor if any other gov failed to
305 auto load due latency restrictions
306*/
307#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
308extern struct cpufreq_governor cpufreq_gov_performance;
309#endif
310#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
311#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
312#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
313extern struct cpufreq_governor cpufreq_gov_powersave;
314#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
315#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
316extern struct cpufreq_governor cpufreq_gov_userspace;
317#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
318#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
319extern struct cpufreq_governor cpufreq_gov_ondemand;
320#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
321#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
322extern struct cpufreq_governor cpufreq_gov_conservative;
323#define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
324#endif
325
326
327/*********************************************************************
328 * FREQUENCY TABLE HELPERS *
329 *********************************************************************/
330
331#define CPUFREQ_ENTRY_INVALID ~0
332#define CPUFREQ_TABLE_END ~1
333
334struct cpufreq_frequency_table {
335 unsigned int index; /* any */
336 unsigned int frequency; /* kHz - doesn't need to be in ascending
337 * order */
338};
339
340int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
341 struct cpufreq_frequency_table *table);
342
343int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
344 struct cpufreq_frequency_table *table);
345
346int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
347 struct cpufreq_frequency_table *table,
348 unsigned int target_freq,
349 unsigned int relation,
350 unsigned int *index);
351
352/* the following 3 funtions are for cpufreq core use only */
353struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
354struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
355void cpufreq_cpu_put (struct cpufreq_policy *data);
356
357/* the following are really really optional */
358extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
359
360void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
361 unsigned int cpu);
362
363void cpufreq_frequency_table_put_attr(unsigned int cpu);
364
365
366/*********************************************************************
367 * UNIFIED DEBUG HELPERS *
368 *********************************************************************/
369
370#define CPUFREQ_DEBUG_CORE 1
371#define CPUFREQ_DEBUG_DRIVER 2
372#define CPUFREQ_DEBUG_GOVERNOR 4
373
374#ifdef CONFIG_CPU_FREQ_DEBUG
375
376extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
377 const char *fmt, ...);
378
379#else
380
381#define cpufreq_debug_printk(msg...) do { } while(0)
382
383#endif /* CONFIG_CPU_FREQ_DEBUG */
384
385#endif /* _LINUX_CPUFREQ_H */