1 /* 2 * linux/include/linux/cpufreq.h 3 * 4 * Copyright (C) 2001 Russell King 5 * (C) 2002 - 2003 Dominik Brodowski <[email protected]> 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 #include <asm/div64.h> 27 28 #define CPUFREQ_NAME_LEN 16 29 30 31 /********************************************************************* 32 * CPUFREQ NOTIFIER INTERFACE * 33 *********************************************************************/ 34 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 38 #define CPUFREQ_TRANSITION_NOTIFIER (0) 39 #define CPUFREQ_POLICY_NOTIFIER (1) 40 41 42 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency 43 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 44 * two generic policies are available: 45 */ 46 47 #define CPUFREQ_POLICY_POWERSAVE (1) 48 #define CPUFREQ_POLICY_PERFORMANCE (2) 49 50 /* Frequency values here are CPU kHz so that hardware which doesn't run 51 * with some frequencies can complain without having to guess what per 52 * cent / per mille means. 53 * Maximum transition latency is in nanoseconds - if it's unknown, 54 * CPUFREQ_ETERNAL shall be used. 55 */ 56 57 struct cpufreq_governor; 58 59 #define CPUFREQ_ETERNAL (-1) 60 struct cpufreq_cpuinfo { 61 unsigned int max_freq; 62 unsigned int min_freq; 63 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */ 64 }; 65 66 struct cpufreq_real_policy { 67 unsigned int min; /* in kHz */ 68 unsigned int max; /* in kHz */ 69 unsigned int policy; /* see above */ 70 struct cpufreq_governor *governor; /* see below */ 71 }; 72 73 struct cpufreq_policy { 74 cpumask_t cpus; /* affected CPUs */ 75 unsigned int cpu; /* cpu nr of registered CPU */ 76 struct cpufreq_cpuinfo cpuinfo;/* see above */ 77 78 unsigned int min; /* in kHz */ 79 unsigned int max; /* in kHz */ 80 unsigned int cur; /* in kHz, only needed if cpufreq 81 * governors are used */ 82 unsigned int policy; /* see above */ 83 struct cpufreq_governor *governor; /* see below */ 84 85 struct semaphore lock; /* CPU ->setpolicy or ->target may 86 only be called once a time */ 87 88 struct work_struct update; /* if update_policy() needs to be 89 * called, but you're in IRQ context */ 90 91 struct cpufreq_real_policy user_policy; 92 93 struct kobject kobj; 94 struct completion kobj_unregister; 95 }; 96 97 #define CPUFREQ_ADJUST (0) 98 #define CPUFREQ_INCOMPATIBLE (1) 99 #define CPUFREQ_NOTIFY (2) 100 101 102 /******************** cpufreq transition notifiers *******************/ 103 104 #define CPUFREQ_PRECHANGE (0) 105 #define CPUFREQ_POSTCHANGE (1) 106 #define CPUFREQ_RESUMECHANGE (8) 107 #define CPUFREQ_SUSPENDCHANGE (9) 108 109 struct cpufreq_freqs { 110 unsigned int cpu; /* cpu nr */ 111 unsigned int old; 112 unsigned int new; 113 u8 flags; /* flags of cpufreq_driver, see below. */ 114 }; 115 116 117 /** 118 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 119 * @old: old value 120 * @div: divisor 121 * @mult: multiplier 122 * 123 * 124 * new = old * mult / div 125 */ 126 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 127 { 128 #if BITS_PER_LONG == 32 129 130 u64 result = ((u64) old) * ((u64) mult); 131 do_div(result, div); 132 return (unsigned long) result; 133 134 #elif BITS_PER_LONG == 64 135 136 unsigned long result = old * ((u64) mult); 137 result /= div; 138 return result; 139 140 #endif 141 }; 142 143 /********************************************************************* 144 * CPUFREQ GOVERNORS * 145 *********************************************************************/ 146 147 #define CPUFREQ_GOV_START 1 148 #define CPUFREQ_GOV_STOP 2 149 #define CPUFREQ_GOV_LIMITS 3 150 151 struct cpufreq_governor { 152 char name[CPUFREQ_NAME_LEN]; 153 int (*governor) (struct cpufreq_policy *policy, 154 unsigned int event); 155 struct list_head governor_list; 156 struct module *owner; 157 }; 158 159 /* pass a target to the cpufreq driver 160 */ 161 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 162 unsigned int target_freq, 163 unsigned int relation); 164 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 165 unsigned int target_freq, 166 unsigned int relation); 167 168 169 /* pass an event to the cpufreq governor */ 170 int cpufreq_governor(unsigned int cpu, unsigned int event); 171 172 int cpufreq_register_governor(struct cpufreq_governor *governor); 173 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 174 175 176 /********************************************************************* 177 * CPUFREQ DRIVER INTERFACE * 178 *********************************************************************/ 179 180 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 181 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 182 183 struct freq_attr; 184 185 struct cpufreq_driver { 186 struct module *owner; 187 char name[CPUFREQ_NAME_LEN]; 188 u8 flags; 189 190 /* needed by all drivers */ 191 int (*init) (struct cpufreq_policy *policy); 192 int (*verify) (struct cpufreq_policy *policy); 193 194 /* define one out of two */ 195 int (*setpolicy) (struct cpufreq_policy *policy); 196 int (*target) (struct cpufreq_policy *policy, 197 unsigned int target_freq, 198 unsigned int relation); 199 200 /* should be defined, if possible */ 201 unsigned int (*get) (unsigned int cpu); 202 203 /* optional */ 204 int (*exit) (struct cpufreq_policy *policy); 205 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 206 int (*resume) (struct cpufreq_policy *policy); 207 struct freq_attr **attr; 208 }; 209 210 /* flags */ 211 212 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 213 * all ->init() calls failed */ 214 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 215 * "constants" aren't affected by 216 * frequency transitions */ 217 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 218 * mismatches */ 219 220 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 221 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 222 223 224 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 225 226 227 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 228 { 229 if (policy->min < min) 230 policy->min = min; 231 if (policy->max < min) 232 policy->max = min; 233 if (policy->min > max) 234 policy->min = max; 235 if (policy->max > max) 236 policy->max = max; 237 if (policy->min > policy->max) 238 policy->min = policy->max; 239 return; 240 } 241 242 struct freq_attr { 243 struct attribute attr; 244 ssize_t (*show)(struct cpufreq_policy *, char *); 245 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 246 }; 247 248 249 /********************************************************************* 250 * CPUFREQ 2.6. INTERFACE * 251 *********************************************************************/ 252 int cpufreq_set_policy(struct cpufreq_policy *policy); 253 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 254 int cpufreq_update_policy(unsigned int cpu); 255 256 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 257 unsigned int cpufreq_get(unsigned int cpu); 258 259 260 /********************************************************************* 261 * CPUFREQ DEFAULT GOVERNOR * 262 *********************************************************************/ 263 264 265 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 266 extern struct cpufreq_governor cpufreq_gov_performance; 267 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance 268 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 269 extern struct cpufreq_governor cpufreq_gov_userspace; 270 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace 271 #endif 272 273 274 /********************************************************************* 275 * FREQUENCY TABLE HELPERS * 276 *********************************************************************/ 277 278 #define CPUFREQ_ENTRY_INVALID ~0 279 #define CPUFREQ_TABLE_END ~1 280 281 struct cpufreq_frequency_table { 282 unsigned int index; /* any */ 283 unsigned int frequency; /* kHz - doesn't need to be in ascending 284 * order */ 285 }; 286 287 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 288 struct cpufreq_frequency_table *table); 289 290 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 291 struct cpufreq_frequency_table *table); 292 293 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 294 struct cpufreq_frequency_table *table, 295 unsigned int target_freq, 296 unsigned int relation, 297 unsigned int *index); 298 299 /* the following 3 funtions are for cpufreq core use only */ 300 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 301 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 302 void cpufreq_cpu_put (struct cpufreq_policy *data); 303 304 /* the following are really really optional */ 305 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 306 307 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 308 unsigned int cpu); 309 310 void cpufreq_frequency_table_put_attr(unsigned int cpu); 311 312 313 /********************************************************************* 314 * UNIFIED DEBUG HELPERS * 315 *********************************************************************/ 316 317 #define CPUFREQ_DEBUG_CORE 1 318 #define CPUFREQ_DEBUG_DRIVER 2 319 #define CPUFREQ_DEBUG_GOVERNOR 4 320 321 #ifdef CONFIG_CPU_FREQ_DEBUG 322 323 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 324 const char *fmt, ...); 325 326 #else 327 328 #define cpufreq_debug_printk(msg...) do { } while(0) 329 330 #endif /* CONFIG_CPU_FREQ_DEBUG */ 331 332 #endif /* _LINUX_CPUFREQ_H */ 333