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 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 shared_type; /* ANY or ALL affected CPUs 76 should set cpufreq */ 77 unsigned int cpu; /* cpu nr of registered CPU */ 78 struct cpufreq_cpuinfo cpuinfo;/* see above */ 79 80 unsigned int min; /* in kHz */ 81 unsigned int max; /* in kHz */ 82 unsigned int cur; /* in kHz, only needed if cpufreq 83 * governors are used */ 84 unsigned int policy; /* see above */ 85 struct cpufreq_governor *governor; /* see below */ 86 87 struct mutex lock; /* CPU ->setpolicy or ->target may 88 only be called once a time */ 89 90 struct work_struct update; /* if update_policy() needs to be 91 * called, but you're in IRQ context */ 92 93 struct cpufreq_real_policy user_policy; 94 95 struct kobject kobj; 96 struct completion kobj_unregister; 97 }; 98 99 #define CPUFREQ_ADJUST (0) 100 #define CPUFREQ_INCOMPATIBLE (1) 101 #define CPUFREQ_NOTIFY (2) 102 103 #define CPUFREQ_SHARED_TYPE_ALL (0) /* All dependent CPUs should set freq */ 104 #define CPUFREQ_SHARED_TYPE_ANY (1) /* Freq can be set from any dependent CPU */ 105 106 /******************** cpufreq transition notifiers *******************/ 107 108 #define CPUFREQ_PRECHANGE (0) 109 #define CPUFREQ_POSTCHANGE (1) 110 #define CPUFREQ_RESUMECHANGE (8) 111 #define CPUFREQ_SUSPENDCHANGE (9) 112 113 struct cpufreq_freqs { 114 unsigned int cpu; /* cpu nr */ 115 unsigned int old; 116 unsigned int new; 117 u8 flags; /* flags of cpufreq_driver, see below. */ 118 }; 119 120 121 /** 122 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 123 * @old: old value 124 * @div: divisor 125 * @mult: multiplier 126 * 127 * 128 * new = old * mult / div 129 */ 130 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 131 { 132 #if BITS_PER_LONG == 32 133 134 u64 result = ((u64) old) * ((u64) mult); 135 do_div(result, div); 136 return (unsigned long) result; 137 138 #elif BITS_PER_LONG == 64 139 140 unsigned long result = old * ((u64) mult); 141 result /= div; 142 return result; 143 144 #endif 145 }; 146 147 /********************************************************************* 148 * CPUFREQ GOVERNORS * 149 *********************************************************************/ 150 151 #define CPUFREQ_GOV_START 1 152 #define CPUFREQ_GOV_STOP 2 153 #define CPUFREQ_GOV_LIMITS 3 154 155 struct cpufreq_governor { 156 char name[CPUFREQ_NAME_LEN]; 157 int (*governor) (struct cpufreq_policy *policy, 158 unsigned int event); 159 struct list_head governor_list; 160 struct module *owner; 161 }; 162 163 /* pass a target to the cpufreq driver 164 */ 165 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 166 unsigned int target_freq, 167 unsigned int relation); 168 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 169 unsigned int target_freq, 170 unsigned int relation); 171 172 173 /* pass an event to the cpufreq governor */ 174 int cpufreq_governor(unsigned int cpu, unsigned int event); 175 176 int cpufreq_register_governor(struct cpufreq_governor *governor); 177 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 178 179 180 /********************************************************************* 181 * CPUFREQ DRIVER INTERFACE * 182 *********************************************************************/ 183 184 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 185 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 186 187 struct freq_attr; 188 189 struct cpufreq_driver { 190 struct module *owner; 191 char name[CPUFREQ_NAME_LEN]; 192 u8 flags; 193 194 /* needed by all drivers */ 195 int (*init) (struct cpufreq_policy *policy); 196 int (*verify) (struct cpufreq_policy *policy); 197 198 /* define one out of two */ 199 int (*setpolicy) (struct cpufreq_policy *policy); 200 int (*target) (struct cpufreq_policy *policy, 201 unsigned int target_freq, 202 unsigned int relation); 203 204 /* should be defined, if possible */ 205 unsigned int (*get) (unsigned int cpu); 206 207 /* optional */ 208 int (*exit) (struct cpufreq_policy *policy); 209 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 210 int (*resume) (struct cpufreq_policy *policy); 211 struct freq_attr **attr; 212 }; 213 214 /* flags */ 215 216 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 217 * all ->init() calls failed */ 218 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 219 * "constants" aren't affected by 220 * frequency transitions */ 221 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 222 * mismatches */ 223 224 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 225 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 226 227 228 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 229 230 231 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 232 { 233 if (policy->min < min) 234 policy->min = min; 235 if (policy->max < min) 236 policy->max = min; 237 if (policy->min > max) 238 policy->min = max; 239 if (policy->max > max) 240 policy->max = max; 241 if (policy->min > policy->max) 242 policy->min = policy->max; 243 return; 244 } 245 246 struct freq_attr { 247 struct attribute attr; 248 ssize_t (*show)(struct cpufreq_policy *, char *); 249 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 250 }; 251 252 253 /********************************************************************* 254 * CPUFREQ 2.6. INTERFACE * 255 *********************************************************************/ 256 int cpufreq_set_policy(struct cpufreq_policy *policy); 257 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 258 int cpufreq_update_policy(unsigned int cpu); 259 260 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 261 unsigned int cpufreq_get(unsigned int cpu); 262 263 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 264 #ifdef CONFIG_CPU_FREQ 265 unsigned int cpufreq_quick_get(unsigned int cpu); 266 #else 267 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 268 { 269 return 0; 270 } 271 #endif 272 273 274 /********************************************************************* 275 * CPUFREQ DEFAULT GOVERNOR * 276 *********************************************************************/ 277 278 279 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 280 extern struct cpufreq_governor cpufreq_gov_performance; 281 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance 282 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 283 extern struct cpufreq_governor cpufreq_gov_userspace; 284 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace 285 #endif 286 287 288 /********************************************************************* 289 * FREQUENCY TABLE HELPERS * 290 *********************************************************************/ 291 292 #define CPUFREQ_ENTRY_INVALID ~0 293 #define CPUFREQ_TABLE_END ~1 294 295 struct cpufreq_frequency_table { 296 unsigned int index; /* any */ 297 unsigned int frequency; /* kHz - doesn't need to be in ascending 298 * order */ 299 }; 300 301 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 302 struct cpufreq_frequency_table *table); 303 304 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 305 struct cpufreq_frequency_table *table); 306 307 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 308 struct cpufreq_frequency_table *table, 309 unsigned int target_freq, 310 unsigned int relation, 311 unsigned int *index); 312 313 /* the following 3 funtions are for cpufreq core use only */ 314 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 315 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 316 void cpufreq_cpu_put (struct cpufreq_policy *data); 317 318 /* the following are really really optional */ 319 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 320 321 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 322 unsigned int cpu); 323 324 void cpufreq_frequency_table_put_attr(unsigned int cpu); 325 326 327 /********************************************************************* 328 * UNIFIED DEBUG HELPERS * 329 *********************************************************************/ 330 331 #define CPUFREQ_DEBUG_CORE 1 332 #define CPUFREQ_DEBUG_DRIVER 2 333 #define CPUFREQ_DEBUG_GOVERNOR 4 334 335 #ifdef CONFIG_CPU_FREQ_DEBUG 336 337 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 338 const char *fmt, ...); 339 340 #else 341 342 #define cpufreq_debug_printk(msg...) do { } while(0) 343 344 #endif /* CONFIG_CPU_FREQ_DEBUG */ 345 346 #endif /* _LINUX_CPUFREQ_H */ 347