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
11struct cpufreq_policy {
12	unsigned long min;
13	unsigned long max;
14	char *governor;
15};
16
17struct cpufreq_available_governors {
18	char *governor;
19	struct cpufreq_available_governors *next;
20	struct cpufreq_available_governors *first;
21};
22
23struct cpufreq_available_frequencies {
24	unsigned long frequency;
25	struct cpufreq_available_frequencies *next;
26	struct cpufreq_available_frequencies *first;
27};
28
29
30struct cpufreq_affected_cpus {
31	unsigned int cpu;
32	struct cpufreq_affected_cpus *next;
33	struct cpufreq_affected_cpus *first;
34};
35
36struct 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
46extern "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
57unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
58
59unsigned 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 */
68unsigned 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
77int 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
88char *cpufreq_get_driver(unsigned int cpu);
89
90void 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
100struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu);
101
102void 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
113struct cpufreq_available_governors
114*cpufreq_get_available_governors(unsigned int cpu);
115
116void 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
127struct cpufreq_available_frequencies
128*cpufreq_get_available_frequencies(unsigned int cpu);
129
130void cpufreq_put_available_frequencies(
131		struct cpufreq_available_frequencies *first);
132
133struct cpufreq_available_frequencies
134*cpufreq_get_boost_frequencies(unsigned int cpu);
135
136void 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
146struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned
147							int cpu);
148
149void 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
158struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned
159							int cpu);
160
161void 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
169struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
170					unsigned long long *total_time);
171
172void cpufreq_put_stats(struct cpufreq_stats *stats);
173
174unsigned 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
183int 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
191int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
192int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq);
193int 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
203int 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
213unsigned 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