tools/power/cpupower/lib/cpufreq.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  *  cpufreq.h - definitions for libcpufreq
   4  *
   5  *  Copyright (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
   6  */
   7
   8 #ifndef __CPUPOWER_CPUFREQ_H__
   9 #define __CPUPOWER_CPUFREQ_H__
  10
  11 struct cpufreq_policy {
  12         unsigned long min;
  13         unsigned long max;
  14         char *governor;
  15 };
  16
  17 struct cpufreq_available_governors {
  18         char *governor;
  19         struct cpufreq_available_governors *next;
  20         struct cpufreq_available_governors *first;
  21 };
  22
  23 struct cpufreq_available_frequencies {
  24         unsigned long frequency;
  25         struct cpufreq_available_frequencies *next;
  26         struct cpufreq_available_frequencies *first;
  27 };
  28
  29
  30 struct cpufreq_affected_cpus {
  31         unsigned int cpu;
  32         struct cpufreq_affected_cpus *next;
  33         struct cpufreq_affected_cpus *first;
  34 };
  35
  36 struct cpufreq_stats {
  37         unsigned long frequency;
  38         unsigned long long time_in_state;
  39         struct cpufreq_stats *next;
  40         struct cpufreq_stats *first;
  41 };
  42
  43
  44
  45 #ifdef __cplusplus
  46 extern "C" {
  47 #endif
  48
  49 /* determine current CPU frequency
  50  * - _kernel variant means kernel's opinion of CPU frequency
  51  * - _hardware variant means actual hardware CPU frequency,
  52  *    which is only available to root.
  53  *
  54  * returns 0 on failure, else frequency in kHz.
  55  */
  56
  57 unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
  58
  59 unsigned long cpufreq_get_freq_hardware(unsigned int cpu);
  60
  61 #define cpufreq_get(cpu) cpufreq_get_freq_kernel(cpu);
  62
  63
  64 /* determine CPU transition latency
  65  *
  66  * returns 0 on failure, else transition latency in 10^(-9) s = nanoseconds
  67  */
  68 unsigned long cpufreq_get_transition_latency(unsigned int cpu);
  69
  70
  71 /* determine hardware CPU frequency limits
  72  *
  73  * These may be limited further by thermal, energy or other
  74  * considerations by cpufreq policy notifiers in the kernel.
  75  */
  76
  77 int cpufreq_get_hardware_limits(unsigned int cpu,
  78                                 unsigned long *min,
  79                                 unsigned long *max);
  80
  81
  82 /* determine CPUfreq driver used
  83  *
  84  * Remember to call cpufreq_put_driver when no longer needed
  85  * to avoid memory leakage, please.
  86  */
  87
  88 char *cpufreq_get_driver(unsigned int cpu);
  89
  90 void cpufreq_put_driver(char *ptr);
  91
  92
  93 /* determine CPUfreq policy currently used
  94  *
  95  * Remember to call cpufreq_put_policy when no longer needed
  96  * to avoid memory leakage, please.
  97  */
  98
  99
 100 struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu);
 101
 102 void cpufreq_put_policy(struct cpufreq_policy *policy);
 103
 104
 105 /* determine CPUfreq governors currently available
 106  *
 107  * may be modified by modprobe'ing or rmmod'ing other governors. Please
 108  * free allocated memory by calling cpufreq_put_available_governors
 109  * after use.
 110  */
 111
 112
 113 struct cpufreq_available_governors
 114 *cpufreq_get_available_governors(unsigned int cpu);
 115
 116 void cpufreq_put_available_governors(
 117         struct cpufreq_available_governors *first);
 118
 119
 120 /* determine CPU frequency states available
 121  *
 122  * Only present on _some_ ->target() cpufreq drivers. For information purposes
 123  * only. Please free allocated memory by calling
 124  * cpufreq_put_frequencies after use.
 125  */
 126
 127 struct cpufreq_available_frequencies
 128 *cpufreq_get_available_frequencies(unsigned int cpu);
 129
 130 void cpufreq_put_available_frequencies(
 131                 struct cpufreq_available_frequencies *first);
 132
 133 struct cpufreq_available_frequencies
 134 *cpufreq_get_boost_frequencies(unsigned int cpu);
 135
 136 void cpufreq_put_boost_frequencies(
 137                 struct cpufreq_available_frequencies *first);
 138
 139
 140 /* determine affected CPUs
 141  *
 142  * Remember to call cpufreq_put_affected_cpus when no longer needed
 143  * to avoid memory leakage, please.
 144  */
 145
 146 struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned
 147                                                         int cpu);
 148
 149 void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *first);
 150
 151
 152 /* determine related CPUs
 153  *
 154  * Remember to call cpufreq_put_related_cpus when no longer needed
 155  * to avoid memory leakage, please.
 156  */
 157
 158 struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned
 159                                                         int cpu);
 160
 161 void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *first);
 162
 163
 164 /* determine stats for cpufreq subsystem
 165  *
 166  * This is not available in all kernel versions or configurations.
 167  */
 168
 169 struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
 170                                         unsigned long long *total_time);
 171
 172 void cpufreq_put_stats(struct cpufreq_stats *stats);
 173
 174 unsigned long cpufreq_get_transitions(unsigned int cpu);
 175
 176
 177 /* set new cpufreq policy
 178  *
 179  * Tries to set the passed policy as new policy as close as possible,
 180  * but results may differ depending e.g. on governors being available.
 181  */
 182
 183 int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy);
 184
 185
 186 /* modify a policy by only changing min/max freq or governor
 187  *
 188  * Does not check whether result is what was intended.
 189  */
 190
 191 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
 192 int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq);
 193 int cpufreq_modify_policy_governor(unsigned int cpu, char *governor);
 194
 195
 196 /* set a specific frequency
 197  *
 198  * Does only work if userspace governor can be used and no external
 199  * interference (other calls to this function or to set/modify_policy)
 200  * occurs. Also does not work on ->range() cpufreq drivers.
 201  */
 202
 203 int cpufreq_set_frequency(unsigned int cpu,
 204                                 unsigned long target_frequency);
 205
 206 #ifdef __cplusplus
 207 }
 208 #endif
 209
 210 #endif /* _CPUFREQ_H */