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Linux kernel mirror (for testing)
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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
19struct cpufreq_policy {
20 unsigned long min;
21 unsigned long max;
22 char *governor;
23};
24
25struct cpufreq_available_governors {
26 char *governor;
27 struct cpufreq_available_governors *next;
28 struct cpufreq_available_governors *first;
29};
30
31struct cpufreq_available_frequencies {
32 unsigned long frequency;
33 struct cpufreq_available_frequencies *next;
34 struct cpufreq_available_frequencies *first;
35};
36
37
38struct cpufreq_affected_cpus {
39 unsigned int cpu;
40 struct cpufreq_affected_cpus *next;
41 struct cpufreq_affected_cpus *first;
42};
43
44struct 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
54extern "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
65unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
66
67unsigned 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 */
76unsigned 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
85int 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
96char *cpufreq_get_driver(unsigned int cpu);
97
98void 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
108struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu);
109
110void 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
121struct cpufreq_available_governors
122*cpufreq_get_available_governors(unsigned int cpu);
123
124void 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
135struct cpufreq_available_frequencies
136*cpufreq_get_available_frequencies(unsigned int cpu);
137
138void 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
148struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned
149 int cpu);
150
151void 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
160struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned
161 int cpu);
162
163void 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
171struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
172 unsigned long long *total_time);
173
174void cpufreq_put_stats(struct cpufreq_stats *stats);
175
176unsigned 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
185int 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
193int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
194int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq);
195int 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
205int cpufreq_set_frequency(unsigned int cpu,
206 unsigned long target_frequency);
207
208#ifdef __cplusplus
209}
210#endif
211
212#endif /* _CPUFREQ_H */