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/kobject.h>
18 #include <linux/sysfs.h>
19 #include <linux/completion.h>
20 #include <linux/workqueue.h>
21 #include <linux/cpumask.h>
22 #include <asm/div64.h>
23 
24 #define CPUFREQ_NAME_LEN 16
25 
26 
27 /*********************************************************************
28  *                     CPUFREQ NOTIFIER INTERFACE                    *
29  *********************************************************************/
30 
31 #define CPUFREQ_TRANSITION_NOTIFIER	(0)
32 #define CPUFREQ_POLICY_NOTIFIER		(1)
33 
34 #ifdef CONFIG_CPU_FREQ
35 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
36 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);
37 extern void disable_cpufreq(void);
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 }
disable_cpufreq(void)49 static inline void disable_cpufreq(void) { }
50 #endif		/* CONFIG_CPU_FREQ */
51 
52 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency
53  * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
54  * two generic policies are available:
55  */
56 
57 #define CPUFREQ_POLICY_POWERSAVE	(1)
58 #define CPUFREQ_POLICY_PERFORMANCE	(2)
59 
60 /* Frequency values here are CPU kHz so that hardware which doesn't run
61  * with some frequencies can complain without having to guess what per
62  * cent / per mille means.
63  * Maximum transition latency is in nanoseconds - if it's unknown,
64  * CPUFREQ_ETERNAL shall be used.
65  */
66 
67 struct cpufreq_governor;
68 
69 /* /sys/devices/system/cpu/cpufreq: entry point for global variables */
70 extern struct kobject *cpufreq_global_kobject;
71 
72 #define CPUFREQ_ETERNAL			(-1)
73 struct cpufreq_cpuinfo {
74 	unsigned int		max_freq;
75 	unsigned int		min_freq;
76 
77 	/* in 10^(-9) s = nanoseconds */
78 	unsigned int		transition_latency;
79 };
80 
81 struct cpufreq_real_policy {
82 	unsigned int		min;    /* in kHz */
83 	unsigned int		max;    /* in kHz */
84 	unsigned int		policy; /* see above */
85 	struct cpufreq_governor	*governor; /* see below */
86 };
87 
88 struct cpufreq_policy {
89 	cpumask_var_t		cpus;	/* CPUs requiring sw coordination */
90 	cpumask_var_t		related_cpus; /* CPUs with any coordination */
91 	unsigned int		shared_type; /* ANY or ALL affected CPUs
92 						should set cpufreq */
93 	unsigned int		cpu;    /* cpu nr of registered CPU */
94 	struct cpufreq_cpuinfo	cpuinfo;/* see above */
95 
96 	unsigned int		min;    /* in kHz */
97 	unsigned int		max;    /* in kHz */
98 	unsigned int		cur;    /* in kHz, only needed if cpufreq
99 					 * governors are used */
100 	unsigned int		policy; /* see above */
101 	struct cpufreq_governor	*governor; /* see below */
102 
103 	struct work_struct	update; /* if update_policy() needs to be
104 					 * called, but you're in IRQ context */
105 
106 	struct cpufreq_real_policy	user_policy;
107 
108 	struct kobject		kobj;
109 	struct completion	kobj_unregister;
110 };
111 
112 #define CPUFREQ_ADJUST		(0)
113 #define CPUFREQ_INCOMPATIBLE	(1)
114 #define CPUFREQ_NOTIFY		(2)
115 #define CPUFREQ_START		(3)
116 
117 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
118 #define CPUFREQ_SHARED_TYPE_HW	 (1) /* HW does needed coordination */
119 #define CPUFREQ_SHARED_TYPE_ALL	 (2) /* All dependent CPUs should set freq */
120 #define CPUFREQ_SHARED_TYPE_ANY	 (3) /* Freq can be set from any dependent CPU*/
121 
122 /******************** cpufreq transition notifiers *******************/
123 
124 #define CPUFREQ_PRECHANGE	(0)
125 #define CPUFREQ_POSTCHANGE	(1)
126 #define CPUFREQ_RESUMECHANGE	(8)
127 #define CPUFREQ_SUSPENDCHANGE	(9)
128 
129 struct cpufreq_freqs {
130 	unsigned int cpu;	/* cpu nr */
131 	unsigned int old;
132 	unsigned int new;
133 	u8 flags;		/* flags of cpufreq_driver, see below. */
134 };
135 
136 
137 /**
138  * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
139  * @old:   old value
140  * @div:   divisor
141  * @mult:  multiplier
142  *
143  *
144  *    new = old * mult / div
145  */
cpufreq_scale(unsigned long old,u_int div,u_int mult)146 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
147 {
148 #if BITS_PER_LONG == 32
149 
150 	u64 result = ((u64) old) * ((u64) mult);
151 	do_div(result, div);
152 	return (unsigned long) result;
153 
154 #elif BITS_PER_LONG == 64
155 
156 	unsigned long result = old * ((u64) mult);
157 	result /= div;
158 	return result;
159 
160 #endif
161 };
162 
163 /*********************************************************************
164  *                          CPUFREQ GOVERNORS                        *
165  *********************************************************************/
166 
167 #define CPUFREQ_GOV_START  1
168 #define CPUFREQ_GOV_STOP   2
169 #define CPUFREQ_GOV_LIMITS 3
170 
171 struct cpufreq_governor {
172 	char	name[CPUFREQ_NAME_LEN];
173 	int	(*governor)	(struct cpufreq_policy *policy,
174 				 unsigned int event);
175 	ssize_t	(*show_setspeed)	(struct cpufreq_policy *policy,
176 					 char *buf);
177 	int	(*store_setspeed)	(struct cpufreq_policy *policy,
178 					 unsigned int freq);
179 	unsigned int max_transition_latency; /* HW must be able to switch to
180 			next freq faster than this value in nano secs or we
181 			will fallback to performance governor */
182 	struct list_head	governor_list;
183 	struct module		*owner;
184 };
185 
186 /*
187  * Pass a target to the cpufreq driver.
188  */
189 extern int cpufreq_driver_target(struct cpufreq_policy *policy,
190 				 unsigned int target_freq,
191 				 unsigned int relation);
192 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
193 				   unsigned int target_freq,
194 				   unsigned int relation);
195 
196 
197 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy,
198 				   unsigned int cpu);
199 
200 int cpufreq_register_governor(struct cpufreq_governor *governor);
201 void cpufreq_unregister_governor(struct cpufreq_governor *governor);
202 
203 
204 /*********************************************************************
205  *                      CPUFREQ DRIVER INTERFACE                     *
206  *********************************************************************/
207 
208 #define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
209 #define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */
210 
211 struct freq_attr;
212 
213 struct cpufreq_driver {
214 	struct module           *owner;
215 	char			name[CPUFREQ_NAME_LEN];
216 	u8			flags;
217 
218 	/* needed by all drivers */
219 	int	(*init)		(struct cpufreq_policy *policy);
220 	int	(*verify)	(struct cpufreq_policy *policy);
221 
222 	/* define one out of two */
223 	int	(*setpolicy)	(struct cpufreq_policy *policy);
224 	int	(*target)	(struct cpufreq_policy *policy,
225 				 unsigned int target_freq,
226 				 unsigned int relation);
227 
228 	/* should be defined, if possible */
229 	unsigned int	(*get)	(unsigned int cpu);
230 
231 	/* optional */
232 	unsigned int (*getavg)	(struct cpufreq_policy *policy,
233 				 unsigned int cpu);
234 	int	(*bios_limit)	(int cpu, unsigned int *limit);
235 
236 	int	(*exit)		(struct cpufreq_policy *policy);
237 	int	(*suspend)	(struct cpufreq_policy *policy);
238 	int	(*resume)	(struct cpufreq_policy *policy);
239 	struct freq_attr	**attr;
240 };
241 
242 /* flags */
243 
244 #define CPUFREQ_STICKY		0x01	/* the driver isn't removed even if
245 					 * all ->init() calls failed */
246 #define CPUFREQ_CONST_LOOPS	0x02	/* loops_per_jiffy or other kernel
247 					 * "constants" aren't affected by
248 					 * frequency transitions */
249 #define CPUFREQ_PM_NO_WARN	0x04	/* don't warn on suspend/resume speed
250 					 * mismatches */
251 
252 int cpufreq_register_driver(struct cpufreq_driver *driver_data);
253 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
254 
255 
256 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);
257 
258 
cpufreq_verify_within_limits(struct cpufreq_policy * policy,unsigned int min,unsigned int max)259 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
260 {
261 	if (policy->min < min)
262 		policy->min = min;
263 	if (policy->max < min)
264 		policy->max = min;
265 	if (policy->min > max)
266 		policy->min = max;
267 	if (policy->max > max)
268 		policy->max = max;
269 	if (policy->min > policy->max)
270 		policy->min = policy->max;
271 	return;
272 }
273 
274 struct freq_attr {
275 	struct attribute attr;
276 	ssize_t (*show)(struct cpufreq_policy *, char *);
277 	ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
278 };
279 
280 #define cpufreq_freq_attr_ro(_name)		\
281 static struct freq_attr _name =			\
282 __ATTR(_name, 0444, show_##_name, NULL)
283 
284 #define cpufreq_freq_attr_ro_perm(_name, _perm)	\
285 static struct freq_attr _name =			\
286 __ATTR(_name, _perm, show_##_name, NULL)
287 
288 #define cpufreq_freq_attr_rw(_name)		\
289 static struct freq_attr _name =			\
290 __ATTR(_name, 0644, show_##_name, store_##_name)
291 
292 struct global_attr {
293 	struct attribute attr;
294 	ssize_t (*show)(struct kobject *kobj,
295 			struct attribute *attr, char *buf);
296 	ssize_t (*store)(struct kobject *a, struct attribute *b,
297 			 const char *c, size_t count);
298 };
299 
300 #define define_one_global_ro(_name)		\
301 static struct global_attr _name =		\
302 __ATTR(_name, 0444, show_##_name, NULL)
303 
304 #define define_one_global_rw(_name)		\
305 static struct global_attr _name =		\
306 __ATTR(_name, 0644, show_##_name, store_##_name)
307 
308 
309 /*********************************************************************
310  *                        CPUFREQ 2.6. INTERFACE                     *
311  *********************************************************************/
312 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
313 int cpufreq_update_policy(unsigned int cpu);
314 
315 #ifdef CONFIG_CPU_FREQ
316 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */
317 unsigned int cpufreq_get(unsigned int cpu);
318 #else
cpufreq_get(unsigned int cpu)319 static inline unsigned int cpufreq_get(unsigned int cpu)
320 {
321 	return 0;
322 }
323 #endif
324 
325 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */
326 #ifdef CONFIG_CPU_FREQ
327 unsigned int cpufreq_quick_get(unsigned int cpu);
328 unsigned int cpufreq_quick_get_max(unsigned int cpu);
329 #else
cpufreq_quick_get(unsigned int cpu)330 static inline unsigned int cpufreq_quick_get(unsigned int cpu)
331 {
332 	return 0;
333 }
cpufreq_quick_get_max(unsigned int cpu)334 static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
335 {
336 	return 0;
337 }
338 #endif
339 
340 
341 /*********************************************************************
342  *                       CPUFREQ DEFAULT GOVERNOR                    *
343  *********************************************************************/
344 
345 
346 /*
347   Performance governor is fallback governor if any other gov failed to
348   auto load due latency restrictions
349 */
350 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
351 extern struct cpufreq_governor cpufreq_gov_performance;
352 #endif
353 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
354 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_performance)
355 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
356 extern struct cpufreq_governor cpufreq_gov_powersave;
357 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_powersave)
358 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
359 extern struct cpufreq_governor cpufreq_gov_userspace;
360 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_userspace)
361 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
362 extern struct cpufreq_governor cpufreq_gov_ondemand;
363 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_ondemand)
364 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
365 extern struct cpufreq_governor cpufreq_gov_conservative;
366 #define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_conservative)
367 #endif
368 
369 
370 /*********************************************************************
371  *                     FREQUENCY TABLE HELPERS                       *
372  *********************************************************************/
373 
374 #define CPUFREQ_ENTRY_INVALID ~0
375 #define CPUFREQ_TABLE_END     ~1
376 
377 struct cpufreq_frequency_table {
378 	unsigned int	index;     /* any */
379 	unsigned int	frequency; /* kHz - doesn't need to be in ascending
380 				    * order */
381 };
382 
383 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
384 				    struct cpufreq_frequency_table *table);
385 
386 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
387 				   struct cpufreq_frequency_table *table);
388 
389 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
390 				   struct cpufreq_frequency_table *table,
391 				   unsigned int target_freq,
392 				   unsigned int relation,
393 				   unsigned int *index);
394 
395 /* the following 3 funtions are for cpufreq core use only */
396 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);
397 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
398 void   cpufreq_cpu_put(struct cpufreq_policy *data);
399 
400 /* the following are really really optional */
401 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
402 
403 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
404 				      unsigned int cpu);
405 
406 void cpufreq_frequency_table_put_attr(unsigned int cpu);
407 
408 
409 #endif /* _LINUX_CPUFREQ_H */
410