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/mutex.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 #define CPUFREQ_TRANSITION_NOTIFIER (0) 36 #define CPUFREQ_POLICY_NOTIFIER (1) 37 38 #ifdef CONFIG_CPU_FREQ 39 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); 40 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); 41 #else /* CONFIG_CPU_FREQ */ 42 static inline int cpufreq_register_notifier(struct notifier_block *nb, 43 unsigned int list) 44 { 45 return 0; 46 } 47 static inline int cpufreq_unregister_notifier(struct notifier_block *nb, 48 unsigned int list) 49 { 50 return 0; 51 } 52 #endif /* CONFIG_CPU_FREQ */ 53 54 /* if (cpufreq_driver->target) exists, the ->governor decides what frequency 55 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these 56 * two generic policies are available: 57 */ 58 59 #define CPUFREQ_POLICY_POWERSAVE (1) 60 #define CPUFREQ_POLICY_PERFORMANCE (2) 61 62 /* Frequency values here are CPU kHz so that hardware which doesn't run 63 * with some frequencies can complain without having to guess what per 64 * cent / per mille means. 65 * Maximum transition latency is in nanoseconds - if it's unknown, 66 * CPUFREQ_ETERNAL shall be used. 67 */ 68 69 struct cpufreq_governor; 70 71 #define CPUFREQ_ETERNAL (-1) 72 struct cpufreq_cpuinfo { 73 unsigned int max_freq; 74 unsigned int min_freq; 75 unsigned int transition_latency; /* in 10^(-9) s = nanoseconds */ 76 }; 77 78 struct cpufreq_real_policy { 79 unsigned int min; /* in kHz */ 80 unsigned int max; /* in kHz */ 81 unsigned int policy; /* see above */ 82 struct cpufreq_governor *governor; /* see below */ 83 }; 84 85 struct cpufreq_policy { 86 cpumask_t cpus; /* affected CPUs */ 87 unsigned int shared_type; /* ANY or ALL affected CPUs 88 should set cpufreq */ 89 unsigned int cpu; /* cpu nr of registered CPU */ 90 struct cpufreq_cpuinfo cpuinfo;/* see above */ 91 92 unsigned int min; /* in kHz */ 93 unsigned int max; /* in kHz */ 94 unsigned int cur; /* in kHz, only needed if cpufreq 95 * governors are used */ 96 unsigned int policy; /* see above */ 97 struct cpufreq_governor *governor; /* see below */ 98 99 struct work_struct update; /* if update_policy() needs to be 100 * called, but you're in IRQ context */ 101 102 struct cpufreq_real_policy user_policy; 103 104 struct kobject kobj; 105 struct completion kobj_unregister; 106 }; 107 108 #define CPUFREQ_ADJUST (0) 109 #define CPUFREQ_INCOMPATIBLE (1) 110 #define CPUFREQ_NOTIFY (2) 111 112 #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ 113 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 114 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 115 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 116 117 /******************** cpufreq transition notifiers *******************/ 118 119 #define CPUFREQ_PRECHANGE (0) 120 #define CPUFREQ_POSTCHANGE (1) 121 #define CPUFREQ_RESUMECHANGE (8) 122 #define CPUFREQ_SUSPENDCHANGE (9) 123 124 struct cpufreq_freqs { 125 unsigned int cpu; /* cpu nr */ 126 unsigned int old; 127 unsigned int new; 128 u8 flags; /* flags of cpufreq_driver, see below. */ 129 }; 130 131 132 /** 133 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 134 * @old: old value 135 * @div: divisor 136 * @mult: multiplier 137 * 138 * 139 * new = old * mult / div 140 */ 141 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 142 { 143 #if BITS_PER_LONG == 32 144 145 u64 result = ((u64) old) * ((u64) mult); 146 do_div(result, div); 147 return (unsigned long) result; 148 149 #elif BITS_PER_LONG == 64 150 151 unsigned long result = old * ((u64) mult); 152 result /= div; 153 return result; 154 155 #endif 156 }; 157 158 /********************************************************************* 159 * CPUFREQ GOVERNORS * 160 *********************************************************************/ 161 162 #define CPUFREQ_GOV_START 1 163 #define CPUFREQ_GOV_STOP 2 164 #define CPUFREQ_GOV_LIMITS 3 165 166 struct cpufreq_governor { 167 char name[CPUFREQ_NAME_LEN]; 168 int (*governor) (struct cpufreq_policy *policy, 169 unsigned int event); 170 unsigned int max_transition_latency; /* HW must be able to switch to 171 next freq faster than this value in nano secs or we 172 will fallback to performance governor */ 173 struct list_head governor_list; 174 struct module *owner; 175 }; 176 177 /* pass a target to the cpufreq driver 178 */ 179 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 180 unsigned int target_freq, 181 unsigned int relation); 182 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 183 unsigned int target_freq, 184 unsigned int relation); 185 186 187 extern int __cpufreq_driver_getavg(struct cpufreq_policy *policy); 188 189 int cpufreq_register_governor(struct cpufreq_governor *governor); 190 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 191 192 int lock_policy_rwsem_read(int cpu); 193 int lock_policy_rwsem_write(int cpu); 194 void unlock_policy_rwsem_read(int cpu); 195 void unlock_policy_rwsem_write(int cpu); 196 197 198 /********************************************************************* 199 * CPUFREQ DRIVER INTERFACE * 200 *********************************************************************/ 201 202 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 203 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 204 205 struct freq_attr; 206 207 struct cpufreq_driver { 208 struct module *owner; 209 char name[CPUFREQ_NAME_LEN]; 210 u8 flags; 211 212 /* needed by all drivers */ 213 int (*init) (struct cpufreq_policy *policy); 214 int (*verify) (struct cpufreq_policy *policy); 215 216 /* define one out of two */ 217 int (*setpolicy) (struct cpufreq_policy *policy); 218 int (*target) (struct cpufreq_policy *policy, 219 unsigned int target_freq, 220 unsigned int relation); 221 222 /* should be defined, if possible */ 223 unsigned int (*get) (unsigned int cpu); 224 225 /* optional */ 226 unsigned int (*getavg) (unsigned int cpu); 227 int (*exit) (struct cpufreq_policy *policy); 228 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 229 int (*resume) (struct cpufreq_policy *policy); 230 struct freq_attr **attr; 231 }; 232 233 /* flags */ 234 235 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 236 * all ->init() calls failed */ 237 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 238 * "constants" aren't affected by 239 * frequency transitions */ 240 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 241 * mismatches */ 242 243 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 244 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 245 246 247 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 248 249 250 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 251 { 252 if (policy->min < min) 253 policy->min = min; 254 if (policy->max < min) 255 policy->max = min; 256 if (policy->min > max) 257 policy->min = max; 258 if (policy->max > max) 259 policy->max = max; 260 if (policy->min > policy->max) 261 policy->min = policy->max; 262 return; 263 } 264 265 struct freq_attr { 266 struct attribute attr; 267 ssize_t (*show)(struct cpufreq_policy *, char *); 268 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 269 }; 270 271 272 /********************************************************************* 273 * CPUFREQ 2.6. INTERFACE * 274 *********************************************************************/ 275 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 276 int cpufreq_update_policy(unsigned int cpu); 277 278 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 279 unsigned int cpufreq_get(unsigned int cpu); 280 281 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 282 #ifdef CONFIG_CPU_FREQ 283 unsigned int cpufreq_quick_get(unsigned int cpu); 284 #else 285 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 286 { 287 return 0; 288 } 289 #endif 290 291 292 /********************************************************************* 293 * CPUFREQ DEFAULT GOVERNOR * 294 *********************************************************************/ 295 296 297 /* 298 Performance governor is fallback governor if any other gov failed to 299 auto load due latency restrictions 300 */ 301 #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE 302 extern struct cpufreq_governor cpufreq_gov_performance; 303 #endif 304 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 305 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) 306 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 307 extern struct cpufreq_governor cpufreq_gov_userspace; 308 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_userspace) 309 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND) 310 extern struct cpufreq_governor cpufreq_gov_ondemand; 311 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_ondemand) 312 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE) 313 extern struct cpufreq_governor cpufreq_gov_conservative; 314 #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_conservative) 315 #endif 316 317 318 /********************************************************************* 319 * FREQUENCY TABLE HELPERS * 320 *********************************************************************/ 321 322 #define CPUFREQ_ENTRY_INVALID ~0 323 #define CPUFREQ_TABLE_END ~1 324 325 struct cpufreq_frequency_table { 326 unsigned int index; /* any */ 327 unsigned int frequency; /* kHz - doesn't need to be in ascending 328 * order */ 329 }; 330 331 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 332 struct cpufreq_frequency_table *table); 333 334 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 335 struct cpufreq_frequency_table *table); 336 337 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 338 struct cpufreq_frequency_table *table, 339 unsigned int target_freq, 340 unsigned int relation, 341 unsigned int *index); 342 343 /* the following 3 funtions are for cpufreq core use only */ 344 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 345 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 346 void cpufreq_cpu_put (struct cpufreq_policy *data); 347 348 /* the following are really really optional */ 349 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 350 351 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 352 unsigned int cpu); 353 354 void cpufreq_frequency_table_put_attr(unsigned int cpu); 355 356 357 /********************************************************************* 358 * UNIFIED DEBUG HELPERS * 359 *********************************************************************/ 360 361 #define CPUFREQ_DEBUG_CORE 1 362 #define CPUFREQ_DEBUG_DRIVER 2 363 #define CPUFREQ_DEBUG_GOVERNOR 4 364 365 #ifdef CONFIG_CPU_FREQ_DEBUG 366 367 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 368 const char *fmt, ...); 369 370 #else 371 372 #define cpufreq_debug_printk(msg...) do { } while(0) 373 374 #endif /* CONFIG_CPU_FREQ_DEBUG */ 375 376 #endif /* _LINUX_CPUFREQ_H */ 377