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15#define pr_fmt(fmt) "cpufreq: " fmt
16
17#include <linux/types.h>
18#include <linux/cpufreq.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/err.h>
23#include <linux/cpumask.h>
24#include <linux/cpu.h>
25#include <linux/smp.h>
26#include <linux/sched.h>
27#include <linux/clk.h>
28#include <linux/percpu.h>
29#include <linux/sh_clk.h>
30
31static DEFINE_PER_CPU(struct clk, sh_cpuclk);
32
33static unsigned int sh_cpufreq_get(unsigned int cpu)
34{
35 return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000;
36}
37
38
39
40
41static int sh_cpufreq_target(struct cpufreq_policy *policy,
42 unsigned int target_freq,
43 unsigned int relation)
44{
45 unsigned int cpu = policy->cpu;
46 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
47 cpumask_t cpus_allowed;
48 struct cpufreq_freqs freqs;
49 struct device *dev;
50 long freq;
51
52 cpus_allowed = current->cpus_allowed;
53 set_cpus_allowed_ptr(current, cpumask_of(cpu));
54
55 BUG_ON(smp_processor_id() != cpu);
56
57 dev = get_cpu_device(cpu);
58
59
60 freq = clk_round_rate(cpuclk, target_freq * 1000);
61
62 if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
63 return -EINVAL;
64
65 dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000);
66
67 freqs.old = sh_cpufreq_get(cpu);
68 freqs.new = (freq + 500) / 1000;
69 freqs.flags = 0;
70
71 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
72 set_cpus_allowed_ptr(current, &cpus_allowed);
73 clk_set_rate(cpuclk, freq);
74 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
75
76 dev_dbg(dev, "set frequency %lu Hz\n", freq);
77
78 return 0;
79}
80
81static int sh_cpufreq_verify(struct cpufreq_policy *policy)
82{
83 struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu);
84 struct cpufreq_frequency_table *freq_table;
85
86 freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
87 if (freq_table)
88 return cpufreq_frequency_table_verify(policy, freq_table);
89
90 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
91 policy->cpuinfo.max_freq);
92
93 policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000;
94 policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
95
96 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
97 policy->cpuinfo.max_freq);
98
99 return 0;
100}
101
102static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
103{
104 unsigned int cpu = policy->cpu;
105 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
106 struct cpufreq_frequency_table *freq_table;
107 struct device *dev;
108
109 dev = get_cpu_device(cpu);
110
111 cpuclk = clk_get(dev, "cpu_clk");
112 if (IS_ERR(cpuclk)) {
113 dev_err(dev, "couldn't get CPU clk\n");
114 return PTR_ERR(cpuclk);
115 }
116
117 policy->cur = sh_cpufreq_get(cpu);
118
119 freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
120 if (freq_table) {
121 int result;
122
123 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
124 if (!result)
125 cpufreq_frequency_table_get_attr(freq_table, cpu);
126 } else {
127 dev_notice(dev, "no frequency table found, falling back "
128 "to rate rounding.\n");
129
130 policy->min = policy->cpuinfo.min_freq =
131 (clk_round_rate(cpuclk, 1) + 500) / 1000;
132 policy->max = policy->cpuinfo.max_freq =
133 (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
134 }
135
136 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
137
138 dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, "
139 "Maximum %u.%03u MHz.\n",
140 policy->min / 1000, policy->min % 1000,
141 policy->max / 1000, policy->max % 1000);
142
143 return 0;
144}
145
146static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy)
147{
148 unsigned int cpu = policy->cpu;
149 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
150
151 cpufreq_frequency_table_put_attr(cpu);
152 clk_put(cpuclk);
153
154 return 0;
155}
156
157static struct freq_attr *sh_freq_attr[] = {
158 &cpufreq_freq_attr_scaling_available_freqs,
159 NULL,
160};
161
162static struct cpufreq_driver sh_cpufreq_driver = {
163 .owner = THIS_MODULE,
164 .name = "sh",
165 .get = sh_cpufreq_get,
166 .target = sh_cpufreq_target,
167 .verify = sh_cpufreq_verify,
168 .init = sh_cpufreq_cpu_init,
169 .exit = sh_cpufreq_cpu_exit,
170 .attr = sh_freq_attr,
171};
172
173static int __init sh_cpufreq_module_init(void)
174{
175 pr_notice("SuperH CPU frequency driver.\n");
176 return cpufreq_register_driver(&sh_cpufreq_driver);
177}
178
179static void __exit sh_cpufreq_module_exit(void)
180{
181 cpufreq_unregister_driver(&sh_cpufreq_driver);
182}
183
184module_init(sh_cpufreq_module_init);
185module_exit(sh_cpufreq_module_exit);
186
187MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
188MODULE_DESCRIPTION("cpufreq driver for SuperH");
189MODULE_LICENSE("GPL");
190
