]>
Commit | Line | Data |
---|---|---|
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.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); | |
59a2f7d9 | 78 | set_cpus_allowed_ptr(current, &cpus_allowed); |
cb5ec75b | 79 | clk_set_rate(cpuclk, freq); |
1da177e4 LT |
80 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
81 | ||
ecbef17a | 82 | dev_dbg(dev, "set frequency %lu Hz\n", freq); |
cb5ec75b | 83 | |
1da177e4 LT |
84 | return 0; |
85 | } | |
86 | ||
1bcfc723 PM |
87 | static 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 | ||
1da177e4 LT |
108 | static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy) |
109 | { | |
3bccf467 PM |
110 | unsigned int cpu = policy->cpu; |
111 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); | |
1bcfc723 | 112 | struct cpufreq_frequency_table *freq_table; |
ecbef17a | 113 | struct device *dev; |
3bccf467 PM |
114 | |
115 | if (!cpu_online(cpu)) | |
1da177e4 LT |
116 | return -ENODEV; |
117 | ||
ecbef17a PM |
118 | dev = get_cpu_device(cpu); |
119 | ||
120 | cpuclk = clk_get(dev, "cpu_clk"); | |
cb5ec75b | 121 | if (IS_ERR(cpuclk)) { |
ecbef17a | 122 | dev_err(dev, "couldn't get CPU clk\n"); |
cb5ec75b PM |
123 | return PTR_ERR(cpuclk); |
124 | } | |
1da177e4 | 125 | |
1bcfc723 | 126 | policy->cur = policy->min = policy->max = sh_cpufreq_get(cpu); |
1da177e4 | 127 | |
1bcfc723 PM |
128 | freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL; |
129 | if (freq_table) { | |
130 | int result = cpufreq_frequency_table_cpuinfo(policy, freq_table); | |
131 | ||
132 | if (!result) | |
133 | cpufreq_frequency_table_get_attr(freq_table, cpu); | |
134 | } else { | |
135 | policy->cpuinfo.min_freq = (clk_round_rate(cpuclk, 1) + 500) / 1000; | |
136 | policy->cpuinfo.max_freq = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; | |
cb5ec75b | 137 | } |
1da177e4 | 138 | |
1bcfc723 PM |
139 | policy->min = policy->cpuinfo.min_freq; |
140 | policy->max = policy->cpuinfo.max_freq; | |
141 | ||
142 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; | |
143 | ||
ecbef17a | 144 | dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, " |
cb5ec75b | 145 | "Maximum %u.%03u MHz.\n", |
ecbef17a | 146 | policy->min / 1000, policy->min % 1000, |
cb5ec75b | 147 | policy->max / 1000, policy->max % 1000); |
1da177e4 | 148 | |
cb5ec75b PM |
149 | return 0; |
150 | } | |
1da177e4 | 151 | |
1bcfc723 | 152 | static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
cb5ec75b | 153 | { |
1bcfc723 PM |
154 | unsigned int cpu = policy->cpu; |
155 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); | |
cb5ec75b | 156 | |
1bcfc723 | 157 | cpufreq_frequency_table_put_attr(cpu); |
cb5ec75b | 158 | clk_put(cpuclk); |
1bcfc723 | 159 | |
1da177e4 LT |
160 | return 0; |
161 | } | |
162 | ||
163 | static struct cpufreq_driver sh_cpufreq_driver = { | |
164 | .owner = THIS_MODULE, | |
cb5ec75b | 165 | .name = "sh", |
cb5ec75b | 166 | .get = sh_cpufreq_get, |
1bcfc723 PM |
167 | .target = sh_cpufreq_target, |
168 | .verify = sh_cpufreq_verify, | |
169 | .init = sh_cpufreq_cpu_init, | |
170 | .exit = sh_cpufreq_cpu_exit, | |
1da177e4 LT |
171 | }; |
172 | ||
cb5ec75b | 173 | static int __init sh_cpufreq_module_init(void) |
1da177e4 | 174 | { |
ecbef17a | 175 | pr_notice("SuperH CPU frequency driver.\n"); |
cb5ec75b | 176 | return cpufreq_register_driver(&sh_cpufreq_driver); |
1da177e4 LT |
177 | } |
178 | ||
cb5ec75b | 179 | static void __exit sh_cpufreq_module_exit(void) |
1da177e4 LT |
180 | { |
181 | cpufreq_unregister_driver(&sh_cpufreq_driver); | |
182 | } | |
183 | ||
cb5ec75b PM |
184 | module_init(sh_cpufreq_module_init); |
185 | module_exit(sh_cpufreq_module_exit); | |
1da177e4 LT |
186 | |
187 | MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); | |
188 | MODULE_DESCRIPTION("cpufreq driver for SuperH"); | |
189 | MODULE_LICENSE("GPL"); |