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