xref: /openbmc/linux/tools/power/cpupower/lib/cpufreq.h (revision ba61bb17)
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 
19 struct cpufreq_policy {
20 	unsigned long min;
21 	unsigned long max;
22 	char *governor;
23 };
24 
25 struct cpufreq_available_governors {
26 	char *governor;
27 	struct cpufreq_available_governors *next;
28 	struct cpufreq_available_governors *first;
29 };
30 
31 struct cpufreq_available_frequencies {
32 	unsigned long frequency;
33 	struct cpufreq_available_frequencies *next;
34 	struct cpufreq_available_frequencies *first;
35 };
36 
37 
38 struct cpufreq_affected_cpus {
39 	unsigned int cpu;
40 	struct cpufreq_affected_cpus *next;
41 	struct cpufreq_affected_cpus *first;
42 };
43 
44 struct 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
54 extern "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 
65 unsigned long cpufreq_get_freq_kernel(unsigned int cpu);
66 
67 unsigned 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  */
76 unsigned 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 
85 int 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 
96 char *cpufreq_get_driver(unsigned int cpu);
97 
98 void 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 
108 struct cpufreq_policy *cpufreq_get_policy(unsigned int cpu);
109 
110 void 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 
121 struct cpufreq_available_governors
122 *cpufreq_get_available_governors(unsigned int cpu);
123 
124 void 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 
135 struct cpufreq_available_frequencies
136 *cpufreq_get_available_frequencies(unsigned int cpu);
137 
138 void 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 
148 struct cpufreq_affected_cpus *cpufreq_get_affected_cpus(unsigned
149 							int cpu);
150 
151 void 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 
160 struct cpufreq_affected_cpus *cpufreq_get_related_cpus(unsigned
161 							int cpu);
162 
163 void 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 
171 struct cpufreq_stats *cpufreq_get_stats(unsigned int cpu,
172 					unsigned long long *total_time);
173 
174 void cpufreq_put_stats(struct cpufreq_stats *stats);
175 
176 unsigned 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 
185 int 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 
193 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
194 int cpufreq_modify_policy_max(unsigned int cpu, unsigned long max_freq);
195 int 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 
205 int cpufreq_set_frequency(unsigned int cpu,
206 				unsigned long target_frequency);
207 
208 #ifdef __cplusplus
209 }
210 #endif
211 
212 #endif /* _CPUFREQ_H */
213