tools/power/cpupower/lib/cpufreq.h

   1 /*
   2  *  cpufreq.h - definitions for libcpufreq
   3  *
   4  *  Copyright (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, version 2 of the License.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  */
  15
  16 #ifndef __CPUPOWER_CPUFREQ_H__
  17 #define __CPUPOWER_CPUFREQ_H__
  18
  19 struct cpufreq_policy {
  20         unsigned long min;
  21         unsigned long max;
  22         char *governor;
  23 };
  24
  25 struct cpufreq_available_governors {
  26         char *governor;
  27         struct cpufreq_available_governors *next;
  28         struct cpufreq_available_governors *first;
  29 };
  30
  31 struct cpufreq_available_frequencies {
  32         unsigned long frequency;
  33         struct cpufreq_available_frequencies *next;
  34         struct cpufreq_available_frequencies *first;
  35 };
  36
  37
  38 struct cpufreq_affected_cpus {
  39         unsigned int cpu;
  40         struct cpufreq_affected_cpus *next;
  41         struct cpufreq_affected_cpus *first;
  42 };
  43
  44 struct cpufreq_stats {
  45         unsigned long frequency;
  46         unsigned long long time_in_state;
  47         struct cpufreq_stats *next;
  48         struct cpufreq_stats *first;
  49 };
  50
  51
  52
  53 #ifdef __cplusplus
  54 extern "C" {
  55 #endif
  56
  57 /* determine current CPU frequency
  58  * - _kernel variant means kernel's opinion of CPU frequency
  59  * - _hardware variant means actual hardware CPU frequency,
  60  *    which is only available to root.
  61  *
  62  * returns 0 on failure, else frequency in kHz.
  63  */
  64
  65 unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
  66
  67 unsigned long cpufreq_get_freq_hardware(unsigned int cpu);
  68
  69 #define cpufreq_get(cpu) cpufreq_get_freq_kernel(cpu);
  70
  71
  72 /* determine CPU transition latency
  73  *
  74  * returns 0 on failure, else transition latency in 10^(-9) s = nanoseconds
  75  */
  76 unsigned long cpufreq_get_transition_latency(unsigned int cpu);
  77
  78
  79 /* determine hardware CPU frequency limits
  80  *
  81  * These may be limited further by thermal, energy or other
  82  * considerations by cpufreq policy notifiers in the kernel.
  83  */
  84
  85 int cpufreq_get_hardware_limits(unsigned int cpu,
  86                                 unsigned long *min,
  87                                 unsigned long *max);
  88
  89
  90 /* determine CPUfreq driver used
  91  *
  92  * Remember to call cpufreq_put_driver when no longer needed
  93  * to avoid memory leakage, please.
  94  */
  95
  96 char *cpufreq_get_driver(unsigned int cpu);
  97
  98 void cpufreq_put_driver(char *ptr);
  99
 100
 101 /* determine CPUfreq policy currently used
 102  *
 103  * Remember to call cpufreq_put_policy when no longer needed
 104  * to avoid memory leakage, please.
 105  */
 106
 107
 108 struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu);
 109
 110 void cpufreq_put_policy(struct cpufreq_policy *policy);
 111
 112
 113 /* determine CPUfreq governors currently available
 114  *
 115  * may be modified by modprobe'ing or rmmod'ing other governors. Please
 116  * free allocated memory by calling cpufreq_put_available_governors
 117  * after use.
 118  */
 119
 120
 121 struct cpufreq_available_governors
 122 *cpufreq_get_available_governors(unsigned int cpu);
 123
 124 void cpufreq_put_available_governors(
 125         struct cpufreq_available_governors *first);
 126
 127
 128 /* determine CPU frequency states available
 129  *
 130  * Only present on _some_ ->target() cpufreq drivers. For information purposes
 131  * only. Please free allocated memory by calling
 132  * cpufreq_put_available_frequencies after use.
 133  */
 134
 135 struct cpufreq_available_frequencies
 136 *cpufreq_get_available_frequencies(unsigned int cpu);
 137
 138 void cpufreq_put_available_frequencies(
 139                 struct cpufreq_available_frequencies *first);
 140
 141
 142 /* determine affected CPUs
 143  *
 144  * Remember to call cpufreq_put_affected_cpus when no longer needed
 145  * to avoid memory leakage, please.
 146  */
 147
 148 struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned
 149                                                         int cpu);
 150
 151 void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *first);
 152
 153
 154 /* determine related CPUs
 155  *
 156  * Remember to call cpufreq_put_related_cpus when no longer needed
 157  * to avoid memory leakage, please.
 158  */
 159
 160 struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned
 161                                                         int cpu);
 162
 163 void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *first);
 164
 165
 166 /* determine stats for cpufreq subsystem
 167  *
 168  * This is not available in all kernel versions or configurations.
 169  */
 170
 171 struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
 172                                         unsigned long long *total_time);
 173
 174 void cpufreq_put_stats(struct cpufreq_stats *stats);
 175
 176 unsigned long cpufreq_get_transitions(unsigned int cpu);
 177
 178
 179 /* set new cpufreq policy
 180  *
 181  * Tries to set the passed policy as new policy as close as possible,
 182  * but results may differ depending e.g. on governors being available.
 183  */
 184
 185 int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy);
 186
 187
 188 /* modify a policy by only changing min/max freq or governor
 189  *
 190  * Does not check whether result is what was intended.
 191  */
 192
 193 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
 194 int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq);
 195 int cpufreq_modify_policy_governor(unsigned int cpu, char *governor);
 196
 197
 198 /* set a specific frequency
 199  *
 200  * Does only work if userspace governor can be used and no external
 201  * interference (other calls to this function or to set/modify_policy)
 202  * occurs. Also does not work on ->range() cpufreq drivers.
 203  */
 204
 205 int cpufreq_set_frequency(unsigned int cpu,
 206                                 unsigned long target_frequency);
 207
 208 #ifdef __cplusplus
 209 }
 210 #endif
 211
 212 #endif /* _CPUFREQ_H */