1/*
2 * linux/drivers/cpufreq/freq_table.c
3 *
4 * Copyright (C) 2002 - 2003 Dominik Brodowski
5 */
6
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/cpufreq.h>
11
12#define dprintk(msg...) \
13	cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "freq-table", msg)
14
15/*********************************************************************
16 *                     FREQUENCY TABLE HELPERS                       *
17 *********************************************************************/
18
19int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
20				    struct cpufreq_frequency_table *table)
21{
22	unsigned int min_freq = ~0;
23	unsigned int max_freq = 0;
24	unsigned int i;
25
26	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
27		unsigned int freq = table[i].frequency;
28		if (freq == CPUFREQ_ENTRY_INVALID) {
29			dprintk("table entry %u is invalid, skipping\n", i);
30
31			continue;
32		}
33		dprintk("table entry %u: %u kHz, %u index\n",
34					i, freq, table[i].index);
35		if (freq < min_freq)
36			min_freq = freq;
37		if (freq > max_freq)
38			max_freq = freq;
39	}
40
41	policy->min = policy->cpuinfo.min_freq = min_freq;
42	policy->max = policy->cpuinfo.max_freq = max_freq;
43
44	if (policy->min == ~0)
45		return -EINVAL;
46	else
47		return 0;
48}
49EXPORT_SYMBOL_GPL(cpufreq_frequency_table_cpuinfo);
50
51
52int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
53				   struct cpufreq_frequency_table *table)
54{
55	unsigned int next_larger = ~0;
56	unsigned int i;
57	unsigned int count = 0;
58
59	dprintk("request for verification of policy (%u - %u kHz) for cpu %u\n",
60					policy->min, policy->max, policy->cpu);
61
62	if (!cpu_online(policy->cpu))
63		return -EINVAL;
64
65	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
66				     policy->cpuinfo.max_freq);
67
68	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
69		unsigned int freq = table[i].frequency;
70		if (freq == CPUFREQ_ENTRY_INVALID)
71			continue;
72		if ((freq >= policy->min) && (freq <= policy->max))
73			count++;
74		else if ((next_larger > freq) && (freq > policy->max))
75			next_larger = freq;
76	}
77
78	if (!count)
79		policy->max = next_larger;
80
81	cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
82				     policy->cpuinfo.max_freq);
83
84	dprintk("verification lead to (%u - %u kHz) for cpu %u\n",
85				policy->min, policy->max, policy->cpu);
86
87	return 0;
88}
89EXPORT_SYMBOL_GPL(cpufreq_frequency_table_verify);
90
91
92int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
93				   struct cpufreq_frequency_table *table,
94				   unsigned int target_freq,
95				   unsigned int relation,
96				   unsigned int *index)
97{
98	struct cpufreq_frequency_table optimal = {
99		.index = ~0,
100		.frequency = 0,
101	};
102	struct cpufreq_frequency_table suboptimal = {
103		.index = ~0,
104		.frequency = 0,
105	};
106	unsigned int i;
107
108	dprintk("request for target %u kHz (relation: %u) for cpu %u\n",
109					target_freq, relation, policy->cpu);
110
111	switch (relation) {
112	case CPUFREQ_RELATION_H:
113		suboptimal.frequency = ~0;
114		break;
115	case CPUFREQ_RELATION_L:
116		optimal.frequency = ~0;
117		break;
118	}
119
120	if (!cpu_online(policy->cpu))
121		return -EINVAL;
122
123	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
124		unsigned int freq = table[i].frequency;
125		if (freq == CPUFREQ_ENTRY_INVALID)
126			continue;
127		if ((freq < policy->min) || (freq > policy->max))
128			continue;
129		switch(relation) {
130		case CPUFREQ_RELATION_H:
131			if (freq <= target_freq) {
132				if (freq >= optimal.frequency) {
133					optimal.frequency = freq;
134					optimal.index = i;
135				}
136			} else {
137				if (freq <= suboptimal.frequency) {
138					suboptimal.frequency = freq;
139					suboptimal.index = i;
140				}
141			}
142			break;
143		case CPUFREQ_RELATION_L:
144			if (freq >= target_freq) {
145				if (freq <= optimal.frequency) {
146					optimal.frequency = freq;
147					optimal.index = i;
148				}
149			} else {
150				if (freq >= suboptimal.frequency) {
151					suboptimal.frequency = freq;
152					suboptimal.index = i;
153				}
154			}
155			break;
156		}
157	}
158	if (optimal.index > i) {
159		if (suboptimal.index > i)
160			return -EINVAL;
161		*index = suboptimal.index;
162	} else
163		*index = optimal.index;
164
165	dprintk("target is %u (%u kHz, %u)\n", *index, table[*index].frequency,
166		table[*index].index);
167
168	return 0;
169}
170EXPORT_SYMBOL_GPL(cpufreq_frequency_table_target);
171
172static struct cpufreq_frequency_table *show_table[NR_CPUS];
173/**
174 * show_scaling_governor - show the current policy for the specified CPU
175 */
176static ssize_t show_available_freqs (struct cpufreq_policy *policy, char *buf)
177{
178	unsigned int i = 0;
179	unsigned int cpu = policy->cpu;
180	ssize_t count = 0;
181	struct cpufreq_frequency_table *table;
182
183	if (!show_table[cpu])
184		return -ENODEV;
185
186	table = show_table[cpu];
187
188	for (i=0; (table[i].frequency != CPUFREQ_TABLE_END); i++) {
189		if (table[i].frequency == CPUFREQ_ENTRY_INVALID)
190			continue;
191		count += sprintf(&buf[count], "%d ", table[i].frequency);
192	}
193	count += sprintf(&buf[count], "\n");
194
195	return count;
196
197}
198
199struct freq_attr cpufreq_freq_attr_scaling_available_freqs = {
200	.attr = { .name = "scaling_available_frequencies",
201		  .mode = 0444,
202		  .owner=THIS_MODULE
203		},
204	.show = show_available_freqs,
205};
206EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs);
207
208/*
209 * if you use these, you must assure that the frequency table is valid
210 * all the time between get_attr and put_attr!
211 */
212void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
213				      unsigned int cpu)
214{
215	dprintk("setting show_table for cpu %u to %p\n", cpu, table);
216	show_table[cpu] = table;
217}
218EXPORT_SYMBOL_GPL(cpufreq_frequency_table_get_attr);
219
220void cpufreq_frequency_table_put_attr(unsigned int cpu)
221{
222	dprintk("clearing show_table for cpu %u\n", cpu);
223	show_table[cpu] = NULL;
224}
225EXPORT_SYMBOL_GPL(cpufreq_frequency_table_put_attr);
226
227struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu)
228{
229	return show_table[cpu];
230}
231EXPORT_SYMBOL_GPL(cpufreq_frequency_get_table);
232
233MODULE_AUTHOR ("Dominik Brodowski <linux@brodo.de>");
234MODULE_DESCRIPTION ("CPUfreq frequency table helpers");
235MODULE_LICENSE ("GPL");
236