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