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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * arch/sh/kernel/cpufreq.c | |
3 | * | |
4 | * cpufreq driver for the SuperH processors. | |
5 | * | |
3bccf467 | 6 | * Copyright (C) 2002 - 2012 Paul Mundt |
1da177e4 LT |
7 | * Copyright (C) 2002 M. R. Brown |
8 | * | |
cb5ec75b PM |
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. | |
1da177e4 | 16 | */ |
ecbef17a PM |
17 | #define pr_fmt(fmt) "cpufreq: " fmt |
18 | ||
1da177e4 LT |
19 | #include <linux/types.h> |
20 | #include <linux/cpufreq.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
1da177e4 | 23 | #include <linux/init.h> |
cb5ec75b | 24 | #include <linux/err.h> |
1da177e4 | 25 | #include <linux/cpumask.h> |
ecbef17a | 26 | #include <linux/cpu.h> |
1da177e4 | 27 | #include <linux/smp.h> |
4e57b681 | 28 | #include <linux/sched.h> /* set_cpus_allowed() */ |
cb5ec75b | 29 | #include <linux/clk.h> |
3bccf467 PM |
30 | #include <linux/percpu.h> |
31 | #include <linux/sh_clk.h> | |
1da177e4 | 32 | |
3bccf467 | 33 | static DEFINE_PER_CPU(struct clk, sh_cpuclk); |
1da177e4 | 34 | |
cb5ec75b | 35 | static unsigned int sh_cpufreq_get(unsigned int cpu) |
1da177e4 | 36 | { |
3bccf467 | 37 | return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000; |
1da177e4 LT |
38 | } |
39 | ||
1da177e4 LT |
40 | /* |
41 | * Here we notify other drivers of the proposed change and the final change. | |
42 | */ | |
cb5ec75b PM |
43 | static int sh_cpufreq_target(struct cpufreq_policy *policy, |
44 | unsigned int target_freq, | |
45 | unsigned int relation) | |
1da177e4 | 46 | { |
cb5ec75b | 47 | unsigned int cpu = policy->cpu; |
3bccf467 | 48 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); |
1da177e4 LT |
49 | cpumask_t cpus_allowed; |
50 | struct cpufreq_freqs freqs; | |
ecbef17a | 51 | struct device *dev; |
cb5ec75b | 52 | long freq; |
1da177e4 LT |
53 | |
54 | if (!cpu_online(cpu)) | |
55 | return -ENODEV; | |
56 | ||
57 | cpus_allowed = current->cpus_allowed; | |
59a2f7d9 | 58 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
1da177e4 LT |
59 | |
60 | BUG_ON(smp_processor_id() != cpu); | |
61 | ||
ecbef17a PM |
62 | dev = get_cpu_device(cpu); |
63 | ||
cb5ec75b PM |
64 | /* Convert target_freq from kHz to Hz */ |
65 | freq = clk_round_rate(cpuclk, target_freq * 1000); | |
1da177e4 | 66 | |
cb5ec75b PM |
67 | if (freq < (policy->min * 1000) || freq > (policy->max * 1000)) |
68 | return -EINVAL; | |
69 | ||
ecbef17a | 70 | dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000); |
1da177e4 | 71 | |
cb5ec75b PM |
72 | freqs.old = sh_cpufreq_get(cpu); |
73 | freqs.new = (freq + 500) / 1000; | |
74 | freqs.flags = 0; | |
75 | ||
b43a7ffb | 76 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); |
59a2f7d9 | 77 | set_cpus_allowed_ptr(current, &cpus_allowed); |
cb5ec75b | 78 | clk_set_rate(cpuclk, freq); |
b43a7ffb | 79 | cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); |
1da177e4 | 80 | |
ecbef17a | 81 | dev_dbg(dev, "set frequency %lu Hz\n", freq); |
cb5ec75b | 82 | |
1da177e4 LT |
83 | return 0; |
84 | } | |
85 | ||
1bcfc723 PM |
86 | static int sh_cpufreq_verify(struct cpufreq_policy *policy) |
87 | { | |
88 | struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu); | |
89 | struct cpufreq_frequency_table *freq_table; | |
90 | ||
91 | freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL; | |
92 | if (freq_table) | |
93 | return cpufreq_frequency_table_verify(policy, freq_table); | |
94 | ||
95 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | |
96 | policy->cpuinfo.max_freq); | |
97 | ||
98 | policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000; | |
99 | policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; | |
100 | ||
101 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | |
102 | policy->cpuinfo.max_freq); | |
103 | ||
104 | return 0; | |
105 | } | |
106 | ||
1da177e4 LT |
107 | static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy) |
108 | { | |
3bccf467 PM |
109 | unsigned int cpu = policy->cpu; |
110 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); | |
1bcfc723 | 111 | struct cpufreq_frequency_table *freq_table; |
ecbef17a | 112 | struct device *dev; |
3bccf467 PM |
113 | |
114 | if (!cpu_online(cpu)) | |
1da177e4 LT |
115 | return -ENODEV; |
116 | ||
ecbef17a PM |
117 | dev = get_cpu_device(cpu); |
118 | ||
119 | cpuclk = clk_get(dev, "cpu_clk"); | |
cb5ec75b | 120 | if (IS_ERR(cpuclk)) { |
ecbef17a | 121 | dev_err(dev, "couldn't get CPU clk\n"); |
cb5ec75b PM |
122 | return PTR_ERR(cpuclk); |
123 | } | |
1da177e4 | 124 | |
1bcfc723 | 125 | policy->cur = policy->min = policy->max = sh_cpufreq_get(cpu); |
1da177e4 | 126 | |
1bcfc723 PM |
127 | freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL; |
128 | if (freq_table) { | |
1a565cf0 | 129 | int result; |
1bcfc723 | 130 | |
1a565cf0 | 131 | result = cpufreq_frequency_table_cpuinfo(policy, freq_table); |
1bcfc723 PM |
132 | if (!result) |
133 | cpufreq_frequency_table_get_attr(freq_table, cpu); | |
134 | } else { | |
1a565cf0 PM |
135 | dev_notice(dev, "no frequency table found, falling back " |
136 | "to rate rounding.\n"); | |
137 | ||
138 | policy->cpuinfo.min_freq = | |
139 | (clk_round_rate(cpuclk, 1) + 500) / 1000; | |
140 | policy->cpuinfo.max_freq = | |
141 | (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; | |
cb5ec75b | 142 | } |
1da177e4 | 143 | |
1bcfc723 PM |
144 | policy->min = policy->cpuinfo.min_freq; |
145 | policy->max = policy->cpuinfo.max_freq; | |
146 | ||
147 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
148 | ||
ecbef17a | 149 | dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, " |
cb5ec75b | 150 | "Maximum %u.%03u MHz.\n", |
ecbef17a | 151 | policy->min / 1000, policy->min % 1000, |
cb5ec75b | 152 | policy->max / 1000, policy->max % 1000); |
1da177e4 | 153 | |
cb5ec75b PM |
154 | return 0; |
155 | } | |
1da177e4 | 156 | |
1bcfc723 | 157 | static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
cb5ec75b | 158 | { |
1bcfc723 PM |
159 | unsigned int cpu = policy->cpu; |
160 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); | |
cb5ec75b | 161 | |
1bcfc723 | 162 | cpufreq_frequency_table_put_attr(cpu); |
cb5ec75b | 163 | clk_put(cpuclk); |
1bcfc723 | 164 | |
1da177e4 LT |
165 | return 0; |
166 | } | |
167 | ||
3cbb08ae PM |
168 | static struct freq_attr *sh_freq_attr[] = { |
169 | &cpufreq_freq_attr_scaling_available_freqs, | |
170 | NULL, | |
171 | }; | |
172 | ||
1da177e4 LT |
173 | static struct cpufreq_driver sh_cpufreq_driver = { |
174 | .owner = THIS_MODULE, | |
cb5ec75b | 175 | .name = "sh", |
cb5ec75b | 176 | .get = sh_cpufreq_get, |
1bcfc723 PM |
177 | .target = sh_cpufreq_target, |
178 | .verify = sh_cpufreq_verify, | |
179 | .init = sh_cpufreq_cpu_init, | |
180 | .exit = sh_cpufreq_cpu_exit, | |
3cbb08ae | 181 | .attr = sh_freq_attr, |
1da177e4 LT |
182 | }; |
183 | ||
cb5ec75b | 184 | static int __init sh_cpufreq_module_init(void) |
1da177e4 | 185 | { |
ecbef17a | 186 | pr_notice("SuperH CPU frequency driver.\n"); |
cb5ec75b | 187 | return cpufreq_register_driver(&sh_cpufreq_driver); |
1da177e4 LT |
188 | } |
189 | ||
cb5ec75b | 190 | static void __exit sh_cpufreq_module_exit(void) |
1da177e4 LT |
191 | { |
192 | cpufreq_unregister_driver(&sh_cpufreq_driver); | |
193 | } | |
194 | ||
cb5ec75b PM |
195 | module_init(sh_cpufreq_module_init); |
196 | module_exit(sh_cpufreq_module_exit); | |
1da177e4 LT |
197 | |
198 | MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); | |
199 | MODULE_DESCRIPTION("cpufreq driver for SuperH"); | |
200 | MODULE_LICENSE("GPL"); |