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
36 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
37 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
38 #else /* CONFIG_CPU_FREQ */
cpufreq_register_notifier(struct notifier_block * nb,unsigned int list)39 static inline int cpufreq_register_notifier(struct notifier_block *nb,
40 unsigned int list)
41 {
42 return 0;
43 }
cpufreq_unregister_notifier(struct notifier_block * nb,unsigned int list)44 static 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
66 struct cpufreq_governor;
67
68 #define CPUFREQ_ETERNAL (-1)
69 struct cpufreq_cpuinfo {
70 unsigned int max_freq;
71 unsigned int min_freq;
72 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
73 };
74
75 struct 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
82 struct 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
123 struct 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 */
cpufreq_scale(unsigned long old,u_int div,u_int mult)140 static 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
165 struct 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 */
182 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
183 unsigned int target_freq,
184 unsigned int relation);
185 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
186 unsigned int target_freq,
187 unsigned int relation);
188
189
190 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
191 unsigned int cpu);
192
193 int cpufreq_register_governor(struct cpufreq_governor *governor);
194 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
195
196 int lock_policy_rwsem_read(int cpu);
197 int lock_policy_rwsem_write(int cpu);
198 void unlock_policy_rwsem_read(int cpu);
199 void 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
209 struct freq_attr;
210
211 struct 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
249 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
250 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
251
252
253 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
254
255
cpufreq_verify_within_limits(struct cpufreq_policy * policy,unsigned int min,unsigned int max)256 static 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
271 struct 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 *********************************************************************/
281 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
282 int cpufreq_update_policy(unsigned int cpu);
283
284 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
285 unsigned 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
289 unsigned int cpufreq_quick_get(unsigned int cpu);
290 #else
cpufreq_quick_get(unsigned int cpu)291 static 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
308 extern 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)
313 extern struct cpufreq_governor cpufreq_gov_powersave;
314 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
315 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
316 extern struct cpufreq_governor cpufreq_gov_userspace;
317 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
318 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
319 extern struct cpufreq_governor cpufreq_gov_ondemand;
320 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
321 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
322 extern 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
334 struct cpufreq_frequency_table {
335 unsigned int index; /* any */
336 unsigned int frequency; /* kHz - doesn't need to be in ascending
337 * order */
338 };
339
340 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
341 struct cpufreq_frequency_table *table);
342
343 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
344 struct cpufreq_frequency_table *table);
345
346 int 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 */
353 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
354 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
355 void cpufreq_cpu_put (struct cpufreq_policy *data);
356
357 /* the following are really really optional */
358 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
359
360 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
361 unsigned int cpu);
362
363 void 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
376 extern 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 */
386