Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / drivers / cpufreq / freq_table.c
1 /*
2  * linux/drivers/cpufreq/freq_table.c
3  *
4  * Copyright (C) 2002 - 2003 Dominik Brodowski
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 version 2 as
8  * published by the Free Software Foundation.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/cpufreq.h>
16
17 /*********************************************************************
18  *                     FREQUENCY TABLE HELPERS                       *
19  *********************************************************************/
20
21 int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
22                                     struct cpufreq_frequency_table *table)
23 {
24         unsigned int min_freq = ~0;
25         unsigned int max_freq = 0;
26         unsigned int i;
27
28         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
29                 unsigned int freq = table[i].frequency;
30                 if (freq == CPUFREQ_ENTRY_INVALID) {
31                         pr_debug("table entry %u is invalid, skipping\n", i);
32
33                         continue;
34                 }
35                 pr_debug("table entry %u: %u kHz, %u index\n",
36                                         i, freq, table[i].index);
37                 if (freq < min_freq)
38                         min_freq = freq;
39                 if (freq > max_freq)
40                         max_freq = freq;
41         }
42
43         policy->min = policy->cpuinfo.min_freq = min_freq;
44         policy->max = policy->cpuinfo.max_freq = max_freq;
45
46         if (policy->min == ~0)
47                 return -EINVAL;
48         else
49                 return 0;
50 }
51 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
52
53
54 int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
55                                    struct cpufreq_frequency_table *table)
56 {
57         unsigned int next_larger = ~0;
58         unsigned int i;
59         unsigned int count = 0;
60
61         pr_debug("request for verification of policy (%u - %u kHz) for cpu %u\n",
62                                         policy->min, policy->max, policy->cpu);
63
64         if (!cpu_online(policy->cpu))
65                 return -EINVAL;
66
67         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
68                                      policy->cpuinfo.max_freq);
69
70         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
71                 unsigned int freq = table[i].frequency;
72                 if (freq == CPUFREQ_ENTRY_INVALID)
73                         continue;
74                 if ((freq >= policy->min) && (freq <= policy->max))
75                         count++;
76                 else if ((next_larger > freq) && (freq > policy->max))
77                         next_larger = freq;
78         }
79
80         if (!count)
81                 policy->max = next_larger;
82
83         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
84                                      policy->cpuinfo.max_freq);
85
86         pr_debug("verification lead to (%u - %u kHz) for cpu %u\n",
87                                 policy->min, policy->max, policy->cpu);
88
89         return 0;
90 }
91 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
92
93
94 int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
95                                    struct cpufreq_frequency_table *table,
96                                    unsigned int target_freq,
97                                    unsigned int relation,
98                                    unsigned int *index)
99 {
100         struct cpufreq_frequency_table optimal = {
101                 .index = ~0,
102                 .frequency = 0,
103         };
104         struct cpufreq_frequency_table suboptimal = {
105                 .index = ~0,
106                 .frequency = 0,
107         };
108         unsigned int i;
109
110         pr_debug("request for target %u kHz (relation: %u) for cpu %u\n",
111                                         target_freq, relation, policy->cpu);
112
113         switch (relation) {
114         case CPUFREQ_RELATION_H:
115                 suboptimal.frequency = ~0;
116                 break;
117         case CPUFREQ_RELATION_L:
118                 optimal.frequency = ~0;
119                 break;
120         }
121
122         if (!cpu_online(policy->cpu))
123                 return -EINVAL;
124
125         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
126                 unsigned int freq = table[i].frequency;
127                 if (freq == CPUFREQ_ENTRY_INVALID)
128                         continue;
129                 if ((freq < policy->min) || (freq > policy->max))
130                         continue;
131                 switch (relation) {
132                 case CPUFREQ_RELATION_H:
133                         if (freq <= target_freq) {
134                                 if (freq >= optimal.frequency) {
135                                         optimal.frequency = freq;
136                                         optimal.index = i;
137                                 }
138                         } else {
139                                 if (freq <= suboptimal.frequency) {
140                                         suboptimal.frequency = freq;
141                                         suboptimal.index = i;
142                                 }
143                         }
144                         break;
145                 case CPUFREQ_RELATION_L:
146                         if (freq >= target_freq) {
147                                 if (freq <= optimal.frequency) {
148                                         optimal.frequency = freq;
149                                         optimal.index = i;
150                                 }
151                         } else {
152                                 if (freq >= suboptimal.frequency) {
153                                         suboptimal.frequency = freq;
154                                         suboptimal.index = i;
155                                 }
156                         }
157                         break;
158                 }
159         }
160         if (optimal.index > i) {
161                 if (suboptimal.index > i)
162                         return -EINVAL;
163                 *index = suboptimal.index;
164         } else
165                 *index = optimal.index;
166
167         pr_debug("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
168                 table[*index].index);
169
170         return 0;
171 }
172 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
173
174 static DEFINE_PER_CPU(struct cpufreq_frequency_table *, cpufreq_show_table);
175 /**
176  * show_available_freqs - show available frequencies for the specified CPU
177  */
178 static ssize_t show_available_freqs(struct cpufreq_policy *policy, char *buf)
179 {
180         unsigned int i = 0;
181         unsigned int cpu = policy->cpu;
182         ssize_t count = 0;
183         struct cpufreq_frequency_table *table;
184
185         if (!per_cpu(cpufreq_show_table, cpu))
186                 return -ENODEV;
187
188         table = per_cpu(cpufreq_show_table, cpu);
189
190         for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
191                 if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
192                         continue;
193                 count += sprintf(&buf[count], "%d ", table[i].frequency);
194         }
195         count += sprintf(&buf[count], "\n");
196
197         return count;
198
199 }
200
201 struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
202         .attr = { .name = "scaling_available_frequencies",
203                   .mode = 0444,
204                 },
205         .show = show_available_freqs,
206 };
207 EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
208
209 /*
210  * if you use these, you must assure that the frequency table is valid
211  * all the time between get_attr and put_attr!
212  */
213 void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
214                                       unsigned int cpu)
215 {
216         pr_debug("setting show_table for cpu %u to %p\n", cpu, table);
217         per_cpu(cpufreq_show_table, cpu) = table;
218 }
219 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
220
221 void cpufreq_frequency_table_put_attr(unsigned int cpu)
222 {
223         pr_debug("clearing show_table for cpu %u\n", cpu);
224         per_cpu(cpufreq_show_table, cpu) = NULL;
225 }
226 EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
227
228 struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
229 {
230         return per_cpu(cpufreq_show_table, cpu);
231 }
232 EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
233
234 MODULE_AUTHOR("Dominik Brodowski <linux@brodo.de>");
235 MODULE_DESCRIPTION("CPUfreq frequency table helpers");
236 MODULE_LICENSE("GPL");