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 */
211