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_NONE (0) /* None */ 104 #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ 105 #define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */ 106 #define CPUFREQ_SHARED_TYPE_ANY (3) /* Freq can be set from any dependent CPU*/ 107 108 /******************** cpufreq transition notifiers *******************/ 109 110 #define CPUFREQ_PRECHANGE (0) 111 #define CPUFREQ_POSTCHANGE (1) 112 #define CPUFREQ_RESUMECHANGE (8) 113 #define CPUFREQ_SUSPENDCHANGE (9) 114 115 struct cpufreq_freqs { 116 unsigned int cpu; /* cpu nr */ 117 unsigned int old; 118 unsigned int new; 119 u8 flags; /* flags of cpufreq_driver, see below. */ 120 }; 121 122 123 /** 124 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe) 125 * @old: old value 126 * @div: divisor 127 * @mult: multiplier 128 * 129 * 130 * new = old * mult / div 131 */ 132 static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult) 133 { 134 #if BITS_PER_LONG == 32 135 136 u64 result = ((u64) old) * ((u64) mult); 137 do_div(result, div); 138 return (unsigned long) result; 139 140 #elif BITS_PER_LONG == 64 141 142 unsigned long result = old * ((u64) mult); 143 result /= div; 144 return result; 145 146 #endif 147 }; 148 149 /********************************************************************* 150 * CPUFREQ GOVERNORS * 151 *********************************************************************/ 152 153 #define CPUFREQ_GOV_START 1 154 #define CPUFREQ_GOV_STOP 2 155 #define CPUFREQ_GOV_LIMITS 3 156 157 struct cpufreq_governor { 158 char name[CPUFREQ_NAME_LEN]; 159 int (*governor) (struct cpufreq_policy *policy, 160 unsigned int event); 161 struct list_head governor_list; 162 struct module *owner; 163 }; 164 165 /* pass a target to the cpufreq driver 166 */ 167 extern int cpufreq_driver_target(struct cpufreq_policy *policy, 168 unsigned int target_freq, 169 unsigned int relation); 170 extern int __cpufreq_driver_target(struct cpufreq_policy *policy, 171 unsigned int target_freq, 172 unsigned int relation); 173 174 175 int cpufreq_register_governor(struct cpufreq_governor *governor); 176 void cpufreq_unregister_governor(struct cpufreq_governor *governor); 177 178 179 /********************************************************************* 180 * CPUFREQ DRIVER INTERFACE * 181 *********************************************************************/ 182 183 #define CPUFREQ_RELATION_L 0 /* lowest frequency at or above target */ 184 #define CPUFREQ_RELATION_H 1 /* highest frequency below or at target */ 185 186 struct freq_attr; 187 188 struct cpufreq_driver { 189 struct module *owner; 190 char name[CPUFREQ_NAME_LEN]; 191 u8 flags; 192 193 /* needed by all drivers */ 194 int (*init) (struct cpufreq_policy *policy); 195 int (*verify) (struct cpufreq_policy *policy); 196 197 /* define one out of two */ 198 int (*setpolicy) (struct cpufreq_policy *policy); 199 int (*target) (struct cpufreq_policy *policy, 200 unsigned int target_freq, 201 unsigned int relation); 202 203 /* should be defined, if possible */ 204 unsigned int (*get) (unsigned int cpu); 205 206 /* optional */ 207 int (*exit) (struct cpufreq_policy *policy); 208 int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); 209 int (*resume) (struct cpufreq_policy *policy); 210 struct freq_attr **attr; 211 }; 212 213 /* flags */ 214 215 #define CPUFREQ_STICKY 0x01 /* the driver isn't removed even if 216 * all ->init() calls failed */ 217 #define CPUFREQ_CONST_LOOPS 0x02 /* loops_per_jiffy or other kernel 218 * "constants" aren't affected by 219 * frequency transitions */ 220 #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed 221 * mismatches */ 222 223 int cpufreq_register_driver(struct cpufreq_driver *driver_data); 224 int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); 225 226 227 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state); 228 229 230 static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max) 231 { 232 if (policy->min < min) 233 policy->min = min; 234 if (policy->max < min) 235 policy->max = min; 236 if (policy->min > max) 237 policy->min = max; 238 if (policy->max > max) 239 policy->max = max; 240 if (policy->min > policy->max) 241 policy->min = policy->max; 242 return; 243 } 244 245 struct freq_attr { 246 struct attribute attr; 247 ssize_t (*show)(struct cpufreq_policy *, char *); 248 ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count); 249 }; 250 251 252 /********************************************************************* 253 * CPUFREQ 2.6. INTERFACE * 254 *********************************************************************/ 255 int cpufreq_set_policy(struct cpufreq_policy *policy); 256 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); 257 int cpufreq_update_policy(unsigned int cpu); 258 259 /* query the current CPU frequency (in kHz). If zero, cpufreq couldn't detect it */ 260 unsigned int cpufreq_get(unsigned int cpu); 261 262 /* query the last known CPU freq (in kHz). If zero, cpufreq couldn't detect it */ 263 #ifdef CONFIG_CPU_FREQ 264 unsigned int cpufreq_quick_get(unsigned int cpu); 265 #else 266 static inline unsigned int cpufreq_quick_get(unsigned int cpu) 267 { 268 return 0; 269 } 270 #endif 271 272 273 /********************************************************************* 274 * CPUFREQ DEFAULT GOVERNOR * 275 *********************************************************************/ 276 277 278 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE 279 extern struct cpufreq_governor cpufreq_gov_performance; 280 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance 281 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) 282 extern struct cpufreq_governor cpufreq_gov_userspace; 283 #define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_userspace 284 #endif 285 286 287 /********************************************************************* 288 * FREQUENCY TABLE HELPERS * 289 *********************************************************************/ 290 291 #define CPUFREQ_ENTRY_INVALID ~0 292 #define CPUFREQ_TABLE_END ~1 293 294 struct cpufreq_frequency_table { 295 unsigned int index; /* any */ 296 unsigned int frequency; /* kHz - doesn't need to be in ascending 297 * order */ 298 }; 299 300 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, 301 struct cpufreq_frequency_table *table); 302 303 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy, 304 struct cpufreq_frequency_table *table); 305 306 int cpufreq_frequency_table_target(struct cpufreq_policy *policy, 307 struct cpufreq_frequency_table *table, 308 unsigned int target_freq, 309 unsigned int relation, 310 unsigned int *index); 311 312 /* the following 3 funtions are for cpufreq core use only */ 313 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu); 314 struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu); 315 void cpufreq_cpu_put (struct cpufreq_policy *data); 316 317 /* the following are really really optional */ 318 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; 319 320 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, 321 unsigned int cpu); 322 323 void cpufreq_frequency_table_put_attr(unsigned int cpu); 324 325 326 /********************************************************************* 327 * UNIFIED DEBUG HELPERS * 328 *********************************************************************/ 329 330 #define CPUFREQ_DEBUG_CORE 1 331 #define CPUFREQ_DEBUG_DRIVER 2 332 #define CPUFREQ_DEBUG_GOVERNOR 4 333 334 #ifdef CONFIG_CPU_FREQ_DEBUG 335 336 extern void cpufreq_debug_printk(unsigned int type, const char *prefix, 337 const char *fmt, ...); 338 339 #else 340 341 #define cpufreq_debug_printk(msg...) do { } while(0) 342 343 #endif /* CONFIG_CPU_FREQ_DEBUG */ 344 345 #endif /* _LINUX_CPUFREQ_H */ 346