Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * cpufreq driver for the SuperH processors. |
3 | * | |
3bccf467 | 4 | * Copyright (C) 2002 - 2012 Paul Mundt |
1da177e4 LT |
5 | * Copyright (C) 2002 M. R. Brown |
6 | * | |
cb5ec75b PM |
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. | |
1da177e4 | 14 | */ |
ecbef17a PM |
15 | #define pr_fmt(fmt) "cpufreq: " fmt |
16 | ||
1da177e4 LT |
17 | #include <linux/types.h> |
18 | #include <linux/cpufreq.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/module.h> | |
1da177e4 | 21 | #include <linux/init.h> |
cb5ec75b | 22 | #include <linux/err.h> |
1da177e4 | 23 | #include <linux/cpumask.h> |
ecbef17a | 24 | #include <linux/cpu.h> |
1da177e4 | 25 | #include <linux/smp.h> |
4e57b681 | 26 | #include <linux/sched.h> /* set_cpus_allowed() */ |
cb5ec75b | 27 | #include <linux/clk.h> |
3bccf467 PM |
28 | #include <linux/percpu.h> |
29 | #include <linux/sh_clk.h> | |
1da177e4 | 30 | |
3bccf467 | 31 | static DEFINE_PER_CPU(struct clk, sh_cpuclk); |
1da177e4 | 32 | |
cb5ec75b | 33 | static unsigned int sh_cpufreq_get(unsigned int cpu) |
1da177e4 | 34 | { |
3bccf467 | 35 | return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000; |
1da177e4 LT |
36 | } |
37 | ||
1da177e4 LT |
38 | /* |
39 | * Here we notify other drivers of the proposed change and the final change. | |
40 | */ | |
cb5ec75b PM |
41 | static int sh_cpufreq_target(struct cpufreq_policy *policy, |
42 | unsigned int target_freq, | |
43 | unsigned int relation) | |
1da177e4 | 44 | { |
cb5ec75b | 45 | unsigned int cpu = policy->cpu; |
3bccf467 | 46 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); |
1da177e4 LT |
47 | cpumask_t cpus_allowed; |
48 | struct cpufreq_freqs freqs; | |
ecbef17a | 49 | struct device *dev; |
cb5ec75b | 50 | long freq; |
1da177e4 | 51 | |
1da177e4 | 52 | cpus_allowed = current->cpus_allowed; |
59a2f7d9 | 53 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
1da177e4 LT |
54 | |
55 | BUG_ON(smp_processor_id() != cpu); | |
56 | ||
ecbef17a PM |
57 | dev = get_cpu_device(cpu); |
58 | ||
cb5ec75b PM |
59 | /* Convert target_freq from kHz to Hz */ |
60 | freq = clk_round_rate(cpuclk, target_freq * 1000); | |
1da177e4 | 61 | |
cb5ec75b PM |
62 | if (freq < (policy->min * 1000) || freq > (policy->max * 1000)) |
63 | return -EINVAL; | |
64 | ||
ecbef17a | 65 | dev_dbg(dev, "requested frequency %u Hz\n", target_freq * 1000); |
1da177e4 | 66 | |
cb5ec75b PM |
67 | freqs.old = sh_cpufreq_get(cpu); |
68 | freqs.new = (freq + 500) / 1000; | |
69 | freqs.flags = 0; | |
70 | ||
8fec051e | 71 | cpufreq_freq_transition_begin(policy, &freqs); |
59a2f7d9 | 72 | set_cpus_allowed_ptr(current, &cpus_allowed); |
cb5ec75b | 73 | clk_set_rate(cpuclk, freq); |
8fec051e | 74 | cpufreq_freq_transition_end(policy, &freqs, 0); |
1da177e4 | 75 | |
ecbef17a | 76 | dev_dbg(dev, "set frequency %lu Hz\n", freq); |
cb5ec75b | 77 | |
1da177e4 LT |
78 | return 0; |
79 | } | |
80 | ||
1bcfc723 PM |
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 | ||
be49e346 | 90 | cpufreq_verify_within_cpu_limits(policy); |
1bcfc723 PM |
91 | |
92 | policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000; | |
93 | policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; | |
94 | ||
be49e346 | 95 | cpufreq_verify_within_cpu_limits(policy); |
1bcfc723 PM |
96 | return 0; |
97 | } | |
98 | ||
1da177e4 LT |
99 | static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy) |
100 | { | |
3bccf467 PM |
101 | unsigned int cpu = policy->cpu; |
102 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); | |
1bcfc723 | 103 | struct cpufreq_frequency_table *freq_table; |
ecbef17a | 104 | struct device *dev; |
3bccf467 | 105 | |
ecbef17a PM |
106 | dev = get_cpu_device(cpu); |
107 | ||
108 | cpuclk = clk_get(dev, "cpu_clk"); | |
cb5ec75b | 109 | if (IS_ERR(cpuclk)) { |
ecbef17a | 110 | dev_err(dev, "couldn't get CPU clk\n"); |
cb5ec75b PM |
111 | return PTR_ERR(cpuclk); |
112 | } | |
1da177e4 | 113 | |
1bcfc723 PM |
114 | freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL; |
115 | if (freq_table) { | |
1a565cf0 | 116 | int result; |
1bcfc723 | 117 | |
c25d01b3 VK |
118 | result = cpufreq_table_validate_and_show(policy, freq_table); |
119 | if (result) | |
120 | return result; | |
1bcfc723 | 121 | } else { |
1a565cf0 PM |
122 | dev_notice(dev, "no frequency table found, falling back " |
123 | "to rate rounding.\n"); | |
124 | ||
eb2f50ff | 125 | policy->min = policy->cpuinfo.min_freq = |
1a565cf0 | 126 | (clk_round_rate(cpuclk, 1) + 500) / 1000; |
eb2f50ff | 127 | policy->max = policy->cpuinfo.max_freq = |
1a565cf0 | 128 | (clk_round_rate(cpuclk, ~0UL) + 500) / 1000; |
cb5ec75b | 129 | } |
1da177e4 | 130 | |
1bcfc723 PM |
131 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
132 | ||
ecbef17a | 133 | dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, " |
cb5ec75b | 134 | "Maximum %u.%03u MHz.\n", |
ecbef17a | 135 | policy->min / 1000, policy->min % 1000, |
cb5ec75b | 136 | policy->max / 1000, policy->max % 1000); |
1da177e4 | 137 | |
cb5ec75b PM |
138 | return 0; |
139 | } | |
1da177e4 | 140 | |
1bcfc723 | 141 | static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy) |
cb5ec75b | 142 | { |
1bcfc723 PM |
143 | unsigned int cpu = policy->cpu; |
144 | struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu); | |
cb5ec75b | 145 | |
cb5ec75b | 146 | clk_put(cpuclk); |
1bcfc723 | 147 | |
1da177e4 LT |
148 | return 0; |
149 | } | |
150 | ||
151 | static struct cpufreq_driver sh_cpufreq_driver = { | |
cb5ec75b | 152 | .name = "sh", |
cb5ec75b | 153 | .get = sh_cpufreq_get, |
1bcfc723 PM |
154 | .target = sh_cpufreq_target, |
155 | .verify = sh_cpufreq_verify, | |
156 | .init = sh_cpufreq_cpu_init, | |
157 | .exit = sh_cpufreq_cpu_exit, | |
a8f64dec | 158 | .attr = cpufreq_generic_attr, |
1da177e4 LT |
159 | }; |
160 | ||
cb5ec75b | 161 | static int __init sh_cpufreq_module_init(void) |
1da177e4 | 162 | { |
ecbef17a | 163 | pr_notice("SuperH CPU frequency driver.\n"); |
cb5ec75b | 164 | return cpufreq_register_driver(&sh_cpufreq_driver); |
1da177e4 LT |
165 | } |
166 | ||
cb5ec75b | 167 | static void __exit sh_cpufreq_module_exit(void) |
1da177e4 LT |
168 | { |
169 | cpufreq_unregister_driver(&sh_cpufreq_driver); | |
170 | } | |
171 | ||
cb5ec75b PM |
172 | module_init(sh_cpufreq_module_init); |
173 | module_exit(sh_cpufreq_module_exit); | |
1da177e4 LT |
174 | |
175 | MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); | |
176 | MODULE_DESCRIPTION("cpufreq driver for SuperH"); | |
177 | MODULE_LICENSE("GPL"); |