net/mlx4_core: Reduce harmless SRIOV error message to debug level
[linux-2.6-block.git] / drivers / cpufreq / sh-cpufreq.c
CommitLineData
1da177e4 1/*
1da177e4
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2 * cpufreq driver for the SuperH processors.
3 *
3bccf467 4 * Copyright (C) 2002 - 2012 Paul Mundt
1da177e4
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5 * Copyright (C) 2002 M. R. Brown
6 *
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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 */
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15#define pr_fmt(fmt) "cpufreq: " fmt
16
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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>
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28#include <linux/percpu.h>
29#include <linux/sh_clk.h>
1da177e4 30
3bccf467 31static DEFINE_PER_CPU(struct clk, sh_cpuclk);
1da177e4 32
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33struct cpufreq_target {
34 struct cpufreq_policy *policy;
35 unsigned int freq;
36};
37
cb5ec75b 38static unsigned int sh_cpufreq_get(unsigned int cpu)
1da177e4 39{
3bccf467 40 return (clk_get_rate(&per_cpu(sh_cpuclk, cpu)) + 500) / 1000;
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41}
42
205dcc1e 43static long __sh_cpufreq_target(void *arg)
1da177e4 44{
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45 struct cpufreq_target *target = arg;
46 struct cpufreq_policy *policy = target->policy;
47 int cpu = policy->cpu;
3bccf467 48 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
1da177e4 49 struct cpufreq_freqs freqs;
ecbef17a 50 struct device *dev;
cb5ec75b 51 long freq;
1da177e4 52
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53 if (smp_processor_id() != cpu)
54 return -ENODEV;
1da177e4 55
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56 dev = get_cpu_device(cpu);
57
cb5ec75b 58 /* Convert target_freq from kHz to Hz */
205dcc1e 59 freq = clk_round_rate(cpuclk, target->freq * 1000);
1da177e4 60
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61 if (freq < (policy->min * 1000) || freq > (policy->max * 1000))
62 return -EINVAL;
63
205dcc1e 64 dev_dbg(dev, "requested frequency %u Hz\n", target->freq * 1000);
1da177e4 65
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66 freqs.old = sh_cpufreq_get(cpu);
67 freqs.new = (freq + 500) / 1000;
68 freqs.flags = 0;
69
205dcc1e 70 cpufreq_freq_transition_begin(target->policy, &freqs);
cb5ec75b 71 clk_set_rate(cpuclk, freq);
205dcc1e 72 cpufreq_freq_transition_end(target->policy, &freqs, 0);
1da177e4 73
ecbef17a 74 dev_dbg(dev, "set frequency %lu Hz\n", freq);
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75 return 0;
76}
77
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78/*
79 * Here we notify other drivers of the proposed change and the final change.
80 */
81static int sh_cpufreq_target(struct cpufreq_policy *policy,
82 unsigned int target_freq,
83 unsigned int relation)
84{
85 struct cpufreq_target data = { .policy = policy, .freq = target_freq };
86
87 return work_on_cpu(policy->cpu, __sh_cpufreq_target, &data);
88}
89
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90static int sh_cpufreq_verify(struct cpufreq_policy *policy)
91{
92 struct clk *cpuclk = &per_cpu(sh_cpuclk, policy->cpu);
93 struct cpufreq_frequency_table *freq_table;
94
95 freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
96 if (freq_table)
97 return cpufreq_frequency_table_verify(policy, freq_table);
98
be49e346 99 cpufreq_verify_within_cpu_limits(policy);
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100
101 policy->min = (clk_round_rate(cpuclk, 1) + 500) / 1000;
102 policy->max = (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
103
be49e346 104 cpufreq_verify_within_cpu_limits(policy);
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105 return 0;
106}
107
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108static int sh_cpufreq_cpu_init(struct cpufreq_policy *policy)
109{
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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 114
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115 dev = get_cpu_device(cpu);
116
117 cpuclk = clk_get(dev, "cpu_clk");
cb5ec75b 118 if (IS_ERR(cpuclk)) {
ecbef17a 119 dev_err(dev, "couldn't get CPU clk\n");
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120 return PTR_ERR(cpuclk);
121 }
1da177e4 122
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123 freq_table = cpuclk->nr_freqs ? cpuclk->freq_table : NULL;
124 if (freq_table) {
1a565cf0 125 int result;
1bcfc723 126
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127 result = cpufreq_table_validate_and_show(policy, freq_table);
128 if (result)
129 return result;
1bcfc723 130 } else {
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131 dev_notice(dev, "no frequency table found, falling back "
132 "to rate rounding.\n");
133
eb2f50ff 134 policy->min = policy->cpuinfo.min_freq =
1a565cf0 135 (clk_round_rate(cpuclk, 1) + 500) / 1000;
eb2f50ff 136 policy->max = policy->cpuinfo.max_freq =
1a565cf0 137 (clk_round_rate(cpuclk, ~0UL) + 500) / 1000;
cb5ec75b 138 }
1da177e4 139
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140 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
141
ecbef17a 142 dev_info(dev, "CPU Frequencies - Minimum %u.%03u MHz, "
cb5ec75b 143 "Maximum %u.%03u MHz.\n",
ecbef17a 144 policy->min / 1000, policy->min % 1000,
cb5ec75b 145 policy->max / 1000, policy->max % 1000);
1da177e4 146
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147 return 0;
148}
1da177e4 149
1bcfc723 150static int sh_cpufreq_cpu_exit(struct cpufreq_policy *policy)
cb5ec75b 151{
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152 unsigned int cpu = policy->cpu;
153 struct clk *cpuclk = &per_cpu(sh_cpuclk, cpu);
cb5ec75b 154
cb5ec75b 155 clk_put(cpuclk);
1bcfc723 156
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157 return 0;
158}
159
160static struct cpufreq_driver sh_cpufreq_driver = {
cb5ec75b 161 .name = "sh",
cb5ec75b 162 .get = sh_cpufreq_get,
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163 .target = sh_cpufreq_target,
164 .verify = sh_cpufreq_verify,
165 .init = sh_cpufreq_cpu_init,
166 .exit = sh_cpufreq_cpu_exit,
a8f64dec 167 .attr = cpufreq_generic_attr,
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168};
169
cb5ec75b 170static int __init sh_cpufreq_module_init(void)
1da177e4 171{
ecbef17a 172 pr_notice("SuperH CPU frequency driver.\n");
cb5ec75b 173 return cpufreq_register_driver(&sh_cpufreq_driver);
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174}
175
cb5ec75b 176static void __exit sh_cpufreq_module_exit(void)
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177{
178 cpufreq_unregister_driver(&sh_cpufreq_driver);
179}
180
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181module_init(sh_cpufreq_module_init);
182module_exit(sh_cpufreq_module_exit);
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183
184MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
185MODULE_DESCRIPTION("cpufreq driver for SuperH");
186MODULE_LICENSE("GPL");