cpufreq: mips: move cpufreq driver to drivers/cpufreq
[linux-3.10.git] / drivers / cpufreq / sh-cpufreq.c
1 /*
2  * cpufreq driver for the SuperH processors.
3  *
4  * Copyright (C) 2002 - 2012 Paul Mundt
5  * Copyright (C) 2002 M. R. Brown
6  *
7  * Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c
8  *
9  *   Copyright (C) 2004-2007 Atmel Corporation
10  *
11  * This file is subject to the terms and conditions of the GNU General Public
12  * License.  See the file "COPYING" in the main directory of this archive
13  * for more details.
14  */
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>        /* set_cpus_allowed() */
27 #include <linux/clk.h>
28 #include <linux/percpu.h>
29 #include <linux/sh_clk.h>
30
31 static DEFINE_PER_CPU(struct clk, sh_cpuclk);
32
33 static 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  * Here we notify other drivers of the proposed change and the final change.
40  */
41 static 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         /* Convert target_freq from kHz to Hz */
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
81 static 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
102 static 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
146 static 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
157 static struct freq_attr *sh_freq_attr[] = {
158         &cpufreq_freq_attr_scaling_available_freqs,
159         NULL,
160 };
161
162 static 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
173 static 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
179 static void __exit sh_cpufreq_module_exit(void)
180 {
181         cpufreq_unregister_driver(&sh_cpufreq_driver);
182 }
183
184 module_init(sh_cpufreq_module_init);
185 module_exit(sh_cpufreq_module_exit);
186
187 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
188 MODULE_DESCRIPTION("cpufreq driver for SuperH");
189 MODULE_LICENSE("GPL");