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1/*
2 * arch/sh/kernel/cpufreq.c
3 *
4 * cpufreq driver for the SuperH processors.
5 *
6 * Copyright (C) 2002 - 2012 Paul Mundt
7 * Copyright (C) 2002 M. R. Brown
8 *
9 * Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c
10 *
11 * Copyright (C) 2004-2007 Atmel Corporation
12 *
13 * This file is subject to the terms and conditions of the GNU General Public
14 * License. See the file "COPYING" in the main directory of this archive
15 * for more details.
16 */
17#define pr_fmt(fmt) "cpufreq: " fmt
18
19#include <linux/types.h>
20#include <linux/cpufreq.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/err.h>
25#include <linux/cpumask.h>
26#include <linux/cpu.h>
27#include <linux/smp.h>
28#include <linux/sched.h> /* set_cpus_allowed() */
29#include <linux/clk.h>
30#include <linux/percpu.h>
31#include <linux/sh_clk.h>
32
33static DEFINE_PER_CPU(struct clk, sh_cpuclk);
34
35static unsigned int sh_cpufreq_get(unsigned int cpu)
36{
37 return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000;
38}
39
40/*
41 * Here we notify other drivers of the proposed change and the final change.
42 */
43static int sh_cpufreq_target(struct cpufreq_policy *policy,
44 unsigned int target_freq,
45 unsigned int relation)
46{
47 unsigned int cpu = policy->cpu;
48 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
49 cpumask_t cpus_allowed;
50 struct cpufreq_freqs freqs;
51 struct device *dev;
52 long freq;
53
54 if (!cpu_online(cpu))
55 return -ENODEV;
56
57 cpus_allowed = current->cpus_allowed;
58 set_cpus_allowed_ptr(current, cpumask_of(cpu));
59
60 BUG_ON(smp_processor_id() != cpu);
61
62 dev = get_cpu_device(cpu);
63
64 /* Convert target_freq from kHz to Hz */
65 freq = clk_round_rate(cpuclk, target_freq * 1000);
66
67 if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
68 return -EINVAL;
69
70 dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000);
71
72 freqs.cpu = cpu;
73 freqs.old = sh_cpufreq_get(cpu);
74 freqs.new = (freq + 500) / 1000;
75 freqs.flags = 0;
76
77 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
78 set_cpus_allowed_ptr(current, &cpus_allowed);
79 clk_set_rate(cpuclk, freq);
80 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
81
82 dev_dbg(dev, "set frequency %lu Hz\n", freq);
83
84 return 0;
85}
86
87static int sh_cpufreq_verify(struct cpufreq_policy *policy)
88{
89 struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu);
90 struct cpufreq_frequency_table *freq_table;
91
92 freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
93 if (freq_table)
94 return cpufreq_frequency_table_verify(policy, freq_table);
95
96 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
97 policy->cpuinfo.max_freq);
98
99 policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000;
100 policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
101
102 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
103 policy->cpuinfo.max_freq);
104
105 return 0;
106}
107
108static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
109{
110 unsigned int cpu = policy->cpu;
111 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
112 struct cpufreq_frequency_table *freq_table;
113 struct device *dev;
114
115 if (!cpu_online(cpu))
116 return -ENODEV;
117
118 dev = get_cpu_device(cpu);
119
120 cpuclk = clk_get(dev, "cpu_clk");
121 if (IS_ERR(cpuclk)) {
122 dev_err(dev, "couldn't get CPU clk\n");
123 return PTR_ERR(cpuclk);
124 }
125
126 policy->cur = policy->min = policy->max = sh_cpufreq_get(cpu);
127
128 freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
129 if (freq_table) {
130 int result;
131
132 result = cpufreq_frequency_table_cpuinfo(policy, freq_table);
133 if (!result)
134 cpufreq_frequency_table_get_attr(freq_table, cpu);
135 } else {
136 dev_notice(dev, "no frequency table found, falling back "
137 "to rate rounding.\n");
138
139 policy->cpuinfo.min_freq =
140 (clk_round_rate(cpuclk, 1) + 500) / 1000;
141 policy->cpuinfo.max_freq =
142 (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
143 }
144
145 policy->min = policy->cpuinfo.min_freq;
146 policy->max = policy->cpuinfo.max_freq;
147
148 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
149
150 dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, "
151 "Maximum %u.%03u MHz.\n",
152 policy->min / 1000, policy->min % 1000,
153 policy->max / 1000, policy->max % 1000);
154
155 return 0;
156}
157
158static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy)
159{
160 unsigned int cpu = policy->cpu;
161 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
162
163 cpufreq_frequency_table_put_attr(cpu);
164 clk_put(cpuclk);
165
166 return 0;
167}
168
169static struct freq_attr *sh_freq_attr[] = {
170 &cpufreq_freq_attr_scaling_available_freqs,
171 NULL,
172};
173
174static struct cpufreq_driver sh_cpufreq_driver = {
175 .owner = THIS_MODULE,
176 .name = "sh",
177 .get = sh_cpufreq_get,
178 .target = sh_cpufreq_target,
179 .verify = sh_cpufreq_verify,
180 .init = sh_cpufreq_cpu_init,
181 .exit = sh_cpufreq_cpu_exit,
182 .attr = sh_freq_attr,
183};
184
185static int __init sh_cpufreq_module_init(void)
186{
187 pr_notice("SuperH CPU frequency driver.\n");
188 return cpufreq_register_driver(&sh_cpufreq_driver);
189}
190
191static void __exit sh_cpufreq_module_exit(void)
192{
193 cpufreq_unregister_driver(&sh_cpufreq_driver);
194}
195
196module_init(sh_cpufreq_module_init);
197module_exit(sh_cpufreq_module_exit);
198
199MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
200MODULE_DESCRIPTION("cpufreq driver for SuperH");
201MODULE_LICENSE("GPL");
1/*
2 * arch/sh/kernel/cpufreq.c
3 *
4 * cpufreq driver for the SuperH processors.
5 *
6 * Copyright (C) 2002 - 2007 Paul Mundt
7 * Copyright (C) 2002 M. R. Brown
8 *
9 * Clock framework bits from arch/avr32/mach-at32ap/cpufreq.c
10 *
11 * Copyright (C) 2004-2007 Atmel Corporation
12 *
13 * This file is subject to the terms and conditions of the GNU General Public
14 * License. See the file "COPYING" in the main directory of this archive
15 * for more details.
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/smp.h>
25#include <linux/sched.h> /* set_cpus_allowed() */
26#include <linux/clk.h>
27
28static struct clk *cpuclk;
29
30static unsigned int sh_cpufreq_get(unsigned int cpu)
31{
32 return (clk_get_rate(cpuclk) + 500) / 1000;
33}
34
35/*
36 * Here we notify other drivers of the proposed change and the final change.
37 */
38static int sh_cpufreq_target(struct cpufreq_policy *policy,
39 unsigned int target_freq,
40 unsigned int relation)
41{
42 unsigned int cpu = policy->cpu;
43 cpumask_t cpus_allowed;
44 struct cpufreq_freqs freqs;
45 long freq;
46
47 if (!cpu_online(cpu))
48 return -ENODEV;
49
50 cpus_allowed = current->cpus_allowed;
51 set_cpus_allowed_ptr(current, cpumask_of(cpu));
52
53 BUG_ON(smp_processor_id() != cpu);
54
55 /* Convert target_freq from kHz to Hz */
56 freq = clk_round_rate(cpuclk, target_freq * 1000);
57
58 if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
59 return -EINVAL;
60
61 pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);
62
63 freqs.cpu = cpu;
64 freqs.old = sh_cpufreq_get(cpu);
65 freqs.new = (freq + 500) / 1000;
66 freqs.flags = 0;
67
68 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
69 set_cpus_allowed_ptr(current, &cpus_allowed);
70 clk_set_rate(cpuclk, freq);
71 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
72
73 pr_debug("cpufreq: set frequency %lu Hz\n", freq);
74
75 return 0;
76}
77
78static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
79{
80 if (!cpu_online(policy->cpu))
81 return -ENODEV;
82
83 cpuclk = clk_get(NULL, "cpu_clk");
84 if (IS_ERR(cpuclk)) {
85 printk(KERN_ERR "cpufreq: couldn't get CPU#%d clk\n",
86 policy->cpu);
87 return PTR_ERR(cpuclk);
88 }
89
90 /* cpuinfo and default policy values */
91 policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000;
92 policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
93 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
94
95 policy->cur = sh_cpufreq_get(policy->cpu);
96 policy->min = policy->cpuinfo.min_freq;
97 policy->max = policy->cpuinfo.max_freq;
98
99 /*
100 * Catch the cases where the clock framework hasn't been wired up
101 * properly to support scaling.
102 */
103 if (unlikely(policy->min == policy->max)) {
104 printk(KERN_ERR "cpufreq: clock framework rate rounding "
105 "not supported on CPU#%d.\n", policy->cpu);
106
107 clk_put(cpuclk);
108 return -EINVAL;
109 }
110
111 printk(KERN_INFO "cpufreq: CPU#%d Frequencies - Minimum %u.%03u MHz, "
112 "Maximum %u.%03u MHz.\n",
113 policy->cpu, policy->min / 1000, policy->min % 1000,
114 policy->max / 1000, policy->max % 1000);
115
116 return 0;
117}
118
119static int sh_cpufreq_verify(struct cpufreq_policy *policy)
120{
121 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
122 policy->cpuinfo.max_freq);
123 return 0;
124}
125
126static int sh_cpufreq_exit(struct cpufreq_policy *policy)
127{
128 clk_put(cpuclk);
129 return 0;
130}
131
132static struct cpufreq_driver sh_cpufreq_driver = {
133 .owner = THIS_MODULE,
134 .name = "sh",
135 .init = sh_cpufreq_cpu_init,
136 .verify = sh_cpufreq_verify,
137 .target = sh_cpufreq_target,
138 .get = sh_cpufreq_get,
139 .exit = sh_cpufreq_exit,
140};
141
142static int __init sh_cpufreq_module_init(void)
143{
144 printk(KERN_INFO "cpufreq: SuperH CPU frequency driver.\n");
145 return cpufreq_register_driver(&sh_cpufreq_driver);
146}
147
148static void __exit sh_cpufreq_module_exit(void)
149{
150 cpufreq_unregister_driver(&sh_cpufreq_driver);
151}
152
153module_init(sh_cpufreq_module_init);
154module_exit(sh_cpufreq_module_exit);
155
156MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
157MODULE_DESCRIPTION("cpufreq driver for SuperH");
158MODULE_LICENSE("GPL");