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