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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 *
8 * $Id: cpufreq.h,v 1.36 2003/01/20 17:31:48 db Exp $
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14#ifndef _LINUX_CPUFREQ_H
15#define _LINUX_CPUFREQ_H
16
17#include <linux/config.h>
18#include <linux/notifier.h>
19#include <linux/threads.h>
20#include <linux/device.h>
21#include <linux/kobject.h>
22#include <linux/sysfs.h>
23#include <linux/completion.h>
24#include <linux/workqueue.h>
25#include <linux/cpumask.h>
26
27#define CPUFREQ_NAME_LEN 16
28
29
30/*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
33
34int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
35int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
36
37#define CPUFREQ_TRANSITION_NOTIFIER (0)
38#define CPUFREQ_POLICY_NOTIFIER (1)
39
40
41/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
42 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
43 * two generic policies are available:
44 */
45
46#define CPUFREQ_POLICY_POWERSAVE (1)
47#define CPUFREQ_POLICY_PERFORMANCE (2)
48
49/* Frequency values here are CPU kHz so that hardware which doesn't run
50 * with some frequencies can complain without having to guess what per
51 * cent / per mille means.
52 * Maximum transition latency is in nanoseconds - if it's unknown,
53 * CPUFREQ_ETERNAL shall be used.
54 */
55
56struct cpufreq_governor;
57
58#define CPUFREQ_ETERNAL (-1)
59struct cpufreq_cpuinfo {
60 unsigned int max_freq;
61 unsigned int min_freq;
62 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */
63};
64
65struct cpufreq_real_policy {
66 unsigned int min; /* in kHz */
67 unsigned int max; /* in kHz */
68 unsigned int policy; /* see above */
69 struct cpufreq_governor *governor; /* see below */
70};
71
72struct cpufreq_policy {
73 cpumask_t cpus; /* affected CPUs */
74 unsigned int cpu; /* cpu nr of registered CPU */
75 struct cpufreq_cpuinfo cpuinfo;/* see above */
76
77 unsigned int min; /* in kHz */
78 unsigned int max; /* in kHz */
79 unsigned int cur; /* in kHz, only needed if cpufreq
80 * governors are used */
81 unsigned int policy; /* see above */
82 struct cpufreq_governor *governor; /* see below */
83
84 struct semaphore lock; /* CPU ->setpolicy or ->target may
85 only be called once a time */
86
87 struct work_struct update; /* if update_policy() needs to be
88 * called, but you're in IRQ context */
89
90 struct cpufreq_real_policy user_policy;
91
92 struct kobject kobj;
93 struct completion kobj_unregister;
94};
95
96#define CPUFREQ_ADJUST (0)
97#define CPUFREQ_INCOMPATIBLE (1)
98#define CPUFREQ_NOTIFY (2)
99
100
101/******************** cpufreq transition notifiers *******************/
102
103#define CPUFREQ_PRECHANGE (0)
104#define CPUFREQ_POSTCHANGE (1)
105#define CPUFREQ_RESUMECHANGE (8)
106#define CPUFREQ_SUSPENDCHANGE (9)
107
108struct cpufreq_freqs {
109 unsigned int cpu; /* cpu nr */
110 unsigned int old;
111 unsigned int new;
112 u8 flags; /* flags of cpufreq_driver, see below. */
113};
114
115
116/**
117 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
118 * @old: old value
119 * @div: divisor
120 * @mult: multiplier
121 *
122 *
123 * new = old * mult / div
124 */
125static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
126{
127#if BITS_PER_LONG == 32
128
129 u64 result = ((u64) old) * ((u64) mult);
130 do_div(result, div);
131 return (unsigned long) result;
132
133#elif BITS_PER_LONG == 64
134
135 unsigned long result = old * ((u64) mult);
136 result /= div;
137 return result;
138
139#endif
140};
141
142/*********************************************************************
143 * CPUFREQ GOVERNORS *
144 *********************************************************************/
145
146#define CPUFREQ_GOV_START 1
147#define CPUFREQ_GOV_STOP 2
148#define CPUFREQ_GOV_LIMITS 3
149
150struct cpufreq_governor {
151 char name[CPUFREQ_NAME_LEN];
152 int (*governor) (struct cpufreq_policy *policy,
153 unsigned int event);
154 struct list_head governor_list;
155 struct module *owner;
156};
157
158/* pass a target to the cpufreq driver
159 */
160extern int cpufreq_driver_target(struct cpufreq_policy *policy,
161 unsigned int target_freq,
162 unsigned int relation);
163extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
164 unsigned int target_freq,
165 unsigned int relation);
166
167
168/* pass an event to the cpufreq governor */
169int cpufreq_governor(unsigned int cpu, unsigned int event);
170
171int cpufreq_register_governor(struct cpufreq_governor *governor);
172void cpufreq_unregister_governor(struct cpufreq_governor *governor);
173
174
175/*********************************************************************
176 * CPUFREQ DRIVER INTERFACE *
177 *********************************************************************/
178
179#define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
180#define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
181
182struct freq_attr;
183
184struct cpufreq_driver {
185 struct module *owner;
186 char name[CPUFREQ_NAME_LEN];
187 u8 flags;
188
189 /* needed by all drivers */
190 int (*init) (struct cpufreq_policy *policy);
191 int (*verify) (struct cpufreq_policy *policy);
192
193 /* define one out of two */
194 int (*setpolicy) (struct cpufreq_policy *policy);
195 int (*target) (struct cpufreq_policy *policy,
196 unsigned int target_freq,
197 unsigned int relation);
198
199 /* should be defined, if possible */
200 unsigned int (*get) (unsigned int cpu);
201
202 /* optional */
203 int (*exit) (struct cpufreq_policy *policy);
204 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg);
205 int (*resume) (struct cpufreq_policy *policy);
206 struct freq_attr **attr;
207};
208
209/* flags */
210
211#define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
212 * all ->init() calls failed */
213#define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
214 * "constants" aren't affected by
215 * frequency transitions */
216#define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
217 * mismatches */
218
219int cpufreq_register_driver(struct cpufreq_driver *driver_data);
220int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
221
222
223void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
224
225
226static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
227{
228 if (policy->min < min)
229 policy->min = min;
230 if (policy->max < min)
231 policy->max = min;
232 if (policy->min > max)
233 policy->min = max;
234 if (policy->max > max)
235 policy->max = max;
236 if (policy->min > policy->max)
237 policy->min = policy->max;
238 return;
239}
240
241struct freq_attr {
242 struct attribute attr;
243 ssize_t (*show)(struct cpufreq_policy *, char *);
244 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
245};
246
247
248/*********************************************************************
249 * CPUFREQ 2.6. INTERFACE *
250 *********************************************************************/
251int cpufreq_set_policy(struct cpufreq_policy *policy);
252int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
253int cpufreq_update_policy(unsigned int cpu);
254
255/* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
256unsigned int cpufreq_get(unsigned int cpu);
257
258
259/*********************************************************************
260 * CPUFREQ DEFAULT GOVERNOR *
261 *********************************************************************/
262
263
264#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
265extern struct cpufreq_governor cpufreq_gov_performance;
266#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
267#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
268extern struct cpufreq_governor cpufreq_gov_userspace;
269#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace
270#endif
271
272
273/*********************************************************************
274 * FREQUENCY TABLE HELPERS *
275 *********************************************************************/
276
277#define CPUFREQ_ENTRY_INVALID ~0
278#define CPUFREQ_TABLE_END ~1
279
280struct cpufreq_frequency_table {
281 unsigned int index; /* any */
282 unsigned int frequency; /* kHz - doesn't need to be in ascending
283 * order */
284};
285
286int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
287 struct cpufreq_frequency_table *table);
288
289int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
290 struct cpufreq_frequency_table *table);
291
292int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
293 struct cpufreq_frequency_table *table,
294 unsigned int target_freq,
295 unsigned int relation,
296 unsigned int *index);
297
298/* the following 3 funtions are for cpufreq core use only */
299struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
300struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
301void cpufreq_cpu_put (struct cpufreq_policy *data);
302
303/* the following are really really optional */
304extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
305
306void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
307 unsigned int cpu);
308
309void cpufreq_frequency_table_put_attr(unsigned int cpu);
310
311
312/*********************************************************************
313 * UNIFIED DEBUG HELPERS *
314 *********************************************************************/
315
316#define CPUFREQ_DEBUG_CORE 1
317#define CPUFREQ_DEBUG_DRIVER 2
318#define CPUFREQ_DEBUG_GOVERNOR 4
319
320#ifdef CONFIG_CPU_FREQ_DEBUG
321
322extern void cpufreq_debug_printk(unsigned int type, const char *prefix,
323 const char *fmt, ...);
324
325#else
326
327#define cpufreq_debug_printk(msg...) do { } while(0)
328
329#endif /* CONFIG_CPU_FREQ_DEBUG */
330
331#endif /* _LINUX_CPUFREQ_H */