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 /*
207 * get the sysfs value from specific table
208 *
209 * Read the value with the sysfs file name from specific table. Does
210 * only work if the cpufreq driver has the specific sysfs interfaces.
211 */
212
213 unsigned long cpufreq_get_sysfs_value_from_table(unsigned int cpu,
214 const char **table,
215 unsigned int index,
216 unsigned int size);
217
218 #ifdef __cplusplus
219 }
220 #endif
221
222 #endif /* _CPUFREQ_H */
223
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