2 * linux/include/linux/cpufreq.h
4 * Copyright (C) 2001 Russell King
5 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
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.
11 #ifndef _LINUX_CPUFREQ_H
12 #define _LINUX_CPUFREQ_H
14 #include <asm/cputime.h>
15 #include <linux/mutex.h>
16 #include <linux/notifier.h>
17 #include <linux/threads.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>
25 #define CPUFREQ_NAME_LEN 16
26 /* Print length for names. Extra 1 space for accomodating '\n' in prints */
27 #define CPUFREQ_NAME_PLEN (CPUFREQ_NAME_LEN + 1)
30 /*********************************************************************
31 * CPUFREQ NOTIFIER INTERFACE *
32 *********************************************************************/
34 #define CPUFREQ_TRANSITION_NOTIFIER (0)
35 #define CPUFREQ_POLICY_NOTIFIER (1)
37 #ifdef CONFIG_CPU_FREQ
38 int cpufreq_register_notifier(struct notifier_block
*nb
, unsigned int list
);
39 int cpufreq_unregister_notifier(struct notifier_block
*nb
, unsigned int list
);
40 extern void disable_cpufreq(void);
41 #else /* CONFIG_CPU_FREQ */
42 static inline int cpufreq_register_notifier(struct notifier_block
*nb
,
47 static inline int cpufreq_unregister_notifier(struct notifier_block
*nb
,
52 static inline void disable_cpufreq(void) { }
53 #endif /* CONFIG_CPU_FREQ */
55 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
56 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
57 * two generic policies are available:
60 #define CPUFREQ_POLICY_POWERSAVE (1)
61 #define CPUFREQ_POLICY_PERFORMANCE (2)
63 /* Frequency values here are CPU kHz so that hardware which doesn't run
64 * with some frequencies can complain without having to guess what per
65 * cent / per mille means.
66 * Maximum transition latency is in nanoseconds - if it's unknown,
67 * CPUFREQ_ETERNAL shall be used.
70 struct cpufreq_governor
;
72 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
73 extern struct kobject
*cpufreq_global_kobject
;
75 #define CPUFREQ_ETERNAL (-1)
76 struct cpufreq_cpuinfo
{
77 unsigned int max_freq
;
78 unsigned int min_freq
;
80 /* in 10^(-9) s = nanoseconds */
81 unsigned int transition_latency
;
84 struct cpufreq_real_policy
{
85 unsigned int min
; /* in kHz */
86 unsigned int max
; /* in kHz */
87 unsigned int policy
; /* see above */
88 struct cpufreq_governor
*governor
; /* see below */
91 struct cpufreq_policy
{
92 /* CPUs sharing clock, require sw coordination */
93 cpumask_var_t cpus
; /* Online CPUs only */
94 cpumask_var_t related_cpus
; /* Online + Offline CPUs */
96 unsigned int shared_type
; /* ACPI: ANY or ALL affected CPUs
98 unsigned int cpu
; /* cpu nr of CPU managing this policy */
99 unsigned int last_cpu
; /* cpu nr of previous CPU that managed
101 struct cpufreq_cpuinfo cpuinfo
;/* see above */
103 unsigned int min
; /* in kHz */
104 unsigned int max
; /* in kHz */
105 unsigned int cur
; /* in kHz, only needed if cpufreq
106 * governors are used */
107 unsigned int policy
; /* see above */
108 struct cpufreq_governor
*governor
; /* see below */
110 struct work_struct update
; /* if update_policy() needs to be
111 * called, but you're in IRQ context */
113 struct cpufreq_real_policy user_policy
;
116 struct completion kobj_unregister
;
119 #define CPUFREQ_ADJUST (0)
120 #define CPUFREQ_INCOMPATIBLE (1)
121 #define CPUFREQ_NOTIFY (2)
122 #define CPUFREQ_START (3)
123 #define CPUFREQ_UPDATE_POLICY_CPU (4)
126 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
127 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
128 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
129 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/
131 static inline bool policy_is_shared(struct cpufreq_policy
*policy
)
133 return cpumask_weight(policy
->cpus
) > 1;
136 /******************** cpufreq transition notifiers *******************/
138 #define CPUFREQ_PRECHANGE (0)
139 #define CPUFREQ_POSTCHANGE (1)
140 #define CPUFREQ_RESUMECHANGE (8)
141 #define CPUFREQ_SUSPENDCHANGE (9)
143 struct cpufreq_freqs
{
144 unsigned int cpu
; /* cpu nr */
147 u8 flags
; /* flags of cpufreq_driver, see below. */
152 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
158 * new = old * mult / div
160 static inline unsigned long cpufreq_scale(unsigned long old
, u_int div
, u_int mult
)
162 #if BITS_PER_LONG == 32
164 u64 result
= ((u64
) old
) * ((u64
) mult
);
166 return (unsigned long) result
;
168 #elif BITS_PER_LONG == 64
170 unsigned long result
= old
* ((u64
) mult
);
177 /*********************************************************************
178 * CPUFREQ GOVERNORS *
179 *********************************************************************/
181 #define CPUFREQ_GOV_START 1
182 #define CPUFREQ_GOV_STOP 2
183 #define CPUFREQ_GOV_LIMITS 3
185 struct cpufreq_governor
{
186 char name
[CPUFREQ_NAME_LEN
];
188 int (*governor
) (struct cpufreq_policy
*policy
,
190 ssize_t (*show_setspeed
) (struct cpufreq_policy
*policy
,
192 int (*store_setspeed
) (struct cpufreq_policy
*policy
,
194 unsigned int max_transition_latency
; /* HW must be able to switch to
195 next freq faster than this value in nano secs or we
196 will fallback to performance governor */
197 struct list_head governor_list
;
198 struct module
*owner
;
202 * Pass a target to the cpufreq driver.
204 extern int cpufreq_driver_target(struct cpufreq_policy
*policy
,
205 unsigned int target_freq
,
206 unsigned int relation
);
207 extern int __cpufreq_driver_target(struct cpufreq_policy
*policy
,
208 unsigned int target_freq
,
209 unsigned int relation
);
212 extern int __cpufreq_driver_getavg(struct cpufreq_policy
*policy
,
215 int cpufreq_register_governor(struct cpufreq_governor
*governor
);
216 void cpufreq_unregister_governor(struct cpufreq_governor
*governor
);
219 /*********************************************************************
220 * CPUFREQ DRIVER INTERFACE *
221 *********************************************************************/
223 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */
224 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */
228 struct cpufreq_driver
{
229 struct module
*owner
;
230 char name
[CPUFREQ_NAME_LEN
];
233 /* needed by all drivers */
234 int (*init
) (struct cpufreq_policy
*policy
);
235 int (*verify
) (struct cpufreq_policy
*policy
);
237 /* define one out of two */
238 int (*setpolicy
) (struct cpufreq_policy
*policy
);
239 int (*target
) (struct cpufreq_policy
*policy
,
240 unsigned int target_freq
,
241 unsigned int relation
);
243 /* should be defined, if possible */
244 unsigned int (*get
) (unsigned int cpu
);
247 unsigned int (*getavg
) (struct cpufreq_policy
*policy
,
249 int (*bios_limit
) (int cpu
, unsigned int *limit
);
251 int (*exit
) (struct cpufreq_policy
*policy
);
252 int (*suspend
) (struct cpufreq_policy
*policy
);
253 int (*resume
) (struct cpufreq_policy
*policy
);
254 struct freq_attr
**attr
;
259 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if
260 * all ->init() calls failed */
261 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel
262 * "constants" aren't affected by
263 * frequency transitions */
264 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed
267 int cpufreq_register_driver(struct cpufreq_driver
*driver_data
);
268 int cpufreq_unregister_driver(struct cpufreq_driver
*driver_data
);
271 void cpufreq_notify_transition(struct cpufreq_freqs
*freqs
, unsigned int state
);
274 static inline void cpufreq_verify_within_limits(struct cpufreq_policy
*policy
, unsigned int min
, unsigned int max
)
276 if (policy
->min
< min
)
278 if (policy
->max
< min
)
280 if (policy
->min
> max
)
282 if (policy
->max
> max
)
284 if (policy
->min
> policy
->max
)
285 policy
->min
= policy
->max
;
290 struct attribute attr
;
291 ssize_t (*show
)(struct cpufreq_policy
*, char *);
292 ssize_t (*store
)(struct cpufreq_policy
*, const char *, size_t count
);
295 #define cpufreq_freq_attr_ro(_name) \
296 static struct freq_attr _name = \
297 __ATTR(_name, 0444, show_##_name, NULL)
299 #define cpufreq_freq_attr_ro_perm(_name, _perm) \
300 static struct freq_attr _name = \
301 __ATTR(_name, _perm, show_##_name, NULL)
303 #define cpufreq_freq_attr_rw(_name) \
304 static struct freq_attr _name = \
305 __ATTR(_name, 0644, show_##_name, store_##_name)
308 struct attribute attr
;
309 ssize_t (*show
)(struct kobject
*kobj
,
310 struct attribute
*attr
, char *buf
);
311 ssize_t (*store
)(struct kobject
*a
, struct attribute
*b
,
312 const char *c
, size_t count
);
315 #define define_one_global_ro(_name) \
316 static struct global_attr _name = \
317 __ATTR(_name, 0444, show_##_name, NULL)
319 #define define_one_global_rw(_name) \
320 static struct global_attr _name = \
321 __ATTR(_name, 0644, show_##_name, store_##_name)
323 struct cpufreq_policy
*cpufreq_cpu_get(unsigned int cpu
);
324 void cpufreq_cpu_put(struct cpufreq_policy
*data
);
325 const char *cpufreq_get_current_driver(void);
327 /*********************************************************************
328 * CPUFREQ 2.6. INTERFACE *
329 *********************************************************************/
330 int cpufreq_get_policy(struct cpufreq_policy
*policy
, unsigned int cpu
);
331 int cpufreq_update_policy(unsigned int cpu
);
333 #ifdef CONFIG_CPU_FREQ
334 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
335 unsigned int cpufreq_get(unsigned int cpu
);
337 static inline unsigned int cpufreq_get(unsigned int cpu
)
343 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
344 #ifdef CONFIG_CPU_FREQ
345 unsigned int cpufreq_quick_get(unsigned int cpu
);
346 unsigned int cpufreq_quick_get_max(unsigned int cpu
);
348 static inline unsigned int cpufreq_quick_get(unsigned int cpu
)
352 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu
)
359 /*********************************************************************
360 * CPUFREQ DEFAULT GOVERNOR *
361 *********************************************************************/
365 Performance governor is fallback governor if any other gov failed to
366 auto load due latency restrictions
368 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
369 extern struct cpufreq_governor cpufreq_gov_performance
;
371 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
372 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance)
373 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
374 extern struct cpufreq_governor cpufreq_gov_powersave
;
375 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_powersave)
376 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
377 extern struct cpufreq_governor cpufreq_gov_userspace
;
378 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace)
379 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
380 extern struct cpufreq_governor cpufreq_gov_ondemand
;
381 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand)
382 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
383 extern struct cpufreq_governor cpufreq_gov_conservative
;
384 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative)
388 /*********************************************************************
389 * FREQUENCY TABLE HELPERS *
390 *********************************************************************/
392 #define CPUFREQ_ENTRY_INVALID ~0
393 #define CPUFREQ_TABLE_END ~1
395 struct cpufreq_frequency_table
{
396 unsigned int index
; /* any */
397 unsigned int frequency
; /* kHz - doesn't need to be in ascending
401 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy
*policy
,
402 struct cpufreq_frequency_table
*table
);
404 int cpufreq_frequency_table_verify(struct cpufreq_policy
*policy
,
405 struct cpufreq_frequency_table
*table
);
407 int cpufreq_frequency_table_target(struct cpufreq_policy
*policy
,
408 struct cpufreq_frequency_table
*table
,
409 unsigned int target_freq
,
410 unsigned int relation
,
411 unsigned int *index
);
413 /* the following 3 funtions are for cpufreq core use only */
414 struct cpufreq_frequency_table
*cpufreq_frequency_get_table(unsigned int cpu
);
416 /* the following are really really optional */
417 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs
;
419 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table
*table
,
421 void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy
*policy
);
423 void cpufreq_frequency_table_put_attr(unsigned int cpu
);
424 #endif /* _LINUX_CPUFREQ_H */