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  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #ifndef __CPUPOWER_CPUFREQ_H__
  21 #define __CPUPOWER_CPUFREQ_H__
  22
  23 struct cpufreq_policy {
  24         unsigned long min;
  25         unsigned long max;
  26         char *governor;
  27 };
  28
  29 struct cpufreq_available_governors {
  30         char *governor;
  31         struct cpufreq_available_governors *next;
  32         struct cpufreq_available_governors *first;
  33 };
  34
  35 struct cpufreq_available_frequencies {
  36         unsigned long frequency;
  37         struct cpufreq_available_frequencies *next;
  38         struct cpufreq_available_frequencies *first;
  39 };
  40
  41
  42 struct cpufreq_affected_cpus {
  43         unsigned int cpu;
  44         struct cpufreq_affected_cpus *next;
  45         struct cpufreq_affected_cpus *first;
  46 };
  47
  48 struct cpufreq_stats {
  49         unsigned long frequency;
  50         unsigned long long time_in_state;
  51         struct cpufreq_stats *next;
  52         struct cpufreq_stats *first;
  53 };
  54
  55
  56
  57 #ifdef __cplusplus
  58 extern "C" {
  59 #endif
  60
  61 /* determine current CPU frequency
  62  * - _kernel variant means kernel's opinion of CPU frequency
  63  * - _hardware variant means actual hardware CPU frequency,
  64  *    which is only available to root.
  65  *
  66  * returns 0 on failure, else frequency in kHz.
  67  */
  68
  69 unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
  70
  71 unsigned long cpufreq_get_freq_hardware(unsigned int cpu);
  72
  73 #define cpufreq_get(cpu) cpufreq_get_freq_kernel(cpu);
  74
  75
  76 /* determine CPU transition latency
  77  *
  78  * returns 0 on failure, else transition latency in 10^(-9) s = nanoseconds
  79  */
  80 unsigned long cpufreq_get_transition_latency(unsigned int cpu);
  81
  82
  83 /* determine hardware CPU frequency limits
  84  *
  85  * These may be limited further by thermal, energy or other
  86  * considerations by cpufreq policy notifiers in the kernel.
  87  */
  88
  89 int cpufreq_get_hardware_limits(unsigned int cpu,
  90                                 unsigned long *min,
  91                                 unsigned long *max);
  92
  93
  94 /* determine CPUfreq driver used
  95  *
  96  * Remember to call cpufreq_put_driver when no longer needed
  97  * to avoid memory leakage, please.
  98  */
  99
 100 char *cpufreq_get_driver(unsigned int cpu);
 101
 102 void cpufreq_put_driver(char *ptr);
 103
 104
 105 /* determine CPUfreq policy currently used
 106  *
 107  * Remember to call cpufreq_put_policy when no longer needed
 108  * to avoid memory leakage, please.
 109  */
 110
 111
 112 struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu);
 113
 114 void cpufreq_put_policy(struct cpufreq_policy *policy);
 115
 116
 117 /* determine CPUfreq governors currently available
 118  *
 119  * may be modified by modprobe'ing or rmmod'ing other governors. Please
 120  * free allocated memory by calling cpufreq_put_available_governors
 121  * after use.
 122  */
 123
 124
 125 struct cpufreq_available_governors
 126 *cpufreq_get_available_governors(unsigned int cpu);
 127
 128 void cpufreq_put_available_governors(
 129         struct cpufreq_available_governors *first);
 130
 131
 132 /* determine CPU frequency states available
 133  *
 134  * Only present on _some_ ->target() cpufreq drivers. For information purposes
 135  * only. Please free allocated memory by calling
 136  * cpufreq_put_available_frequencies after use.
 137  */
 138
 139 struct cpufreq_available_frequencies
 140 *cpufreq_get_available_frequencies(unsigned int cpu);
 141
 142 void cpufreq_put_available_frequencies(
 143                 struct cpufreq_available_frequencies *first);
 144
 145
 146 /* determine affected CPUs
 147  *
 148  * Remember to call cpufreq_put_affected_cpus when no longer needed
 149  * to avoid memory leakage, please.
 150  */
 151
 152 struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned
 153                                                         int cpu);
 154
 155 void cpufreq_put_affected_cpus(struct cpufreq_affected_cpus *first);
 156
 157
 158 /* determine related CPUs
 159  *
 160  * Remember to call cpufreq_put_related_cpus when no longer needed
 161  * to avoid memory leakage, please.
 162  */
 163
 164 struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned
 165                                                         int cpu);
 166
 167 void cpufreq_put_related_cpus(struct cpufreq_affected_cpus *first);
 168
 169
 170 /* determine stats for cpufreq subsystem
 171  *
 172  * This is not available in all kernel versions or configurations.
 173  */
 174
 175 struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
 176                                         unsigned long long *total_time);
 177
 178 void cpufreq_put_stats(struct cpufreq_stats *stats);
 179
 180 unsigned long cpufreq_get_transitions(unsigned int cpu);
 181
 182
 183 /* set new cpufreq policy
 184  *
 185  * Tries to set the passed policy as new policy as close as possible,
 186  * but results may differ depending e.g. on governors being available.
 187  */
 188
 189 int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy);
 190
 191
 192 /* modify a policy by only changing min/max freq or governor
 193  *
 194  * Does not check whether result is what was intended.
 195  */
 196
 197 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
 198 int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq);
 199 int cpufreq_modify_policy_governor(unsigned int cpu, char *governor);
 200
 201
 202 /* set a specific frequency
 203  *
 204  * Does only work if userspace governor can be used and no external
 205  * interference (other calls to this function or to set/modify_policy)
 206  * occurs. Also does not work on ->range() cpufreq drivers.
 207  */
 208
 209 int cpufreq_set_frequency(unsigned int cpu,
 210                                 unsigned long target_frequency);
 211
 212 #ifdef __cplusplus
 213 }
 214 #endif
 215
 216 #endif /* _CPUFREQ_H */