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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
/*
* Cpufreq driver for the loongson-2 processors
*
* The 2E revision of loongson processor not support this feature.
*
* Copyright (C) 2006 - 2008 Lemote Inc. & Insititute of Computing Technology
* Author: Yanhua, yanh@lemote.com
*
* 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.
*/
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/sched.h> /* set_cpus_allowed() */
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <asm/clock.h>
#include <asm/idle.h>
#include <asm/mach-loongson/loongson.h>
static uint nowait;
static struct clk *cpuclk;
static void (*saved_cpu_wait) (void);
static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
unsigned long val, void *data);
static struct notifier_block loongson2_cpufreq_notifier_block = {
.notifier_call = loongson2_cpu_freq_notifier
};
static int loongson2_cpu_freq_notifier(struct notifier_block *nb,
unsigned long val, void *data)
{
if (val == CPUFREQ_POSTCHANGE)
current_cpu_data.udelay_val = loops_per_jiffy;
return 0;
}
static unsigned int loongson2_cpufreq_get(unsigned int cpu)
{
return clk_get_rate(cpuclk);
}
/*
* Here we notify other drivers of the proposed change and the final change.
*/
static int loongson2_cpufreq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int cpu = policy->cpu;
unsigned int newstate = 0;
cpumask_t cpus_allowed;
struct cpufreq_freqs freqs;
unsigned int freq;
cpus_allowed = current->cpus_allowed;
set_cpus_allowed_ptr(current, cpumask_of(cpu));
if (cpufreq_frequency_table_target
(policy, &loongson2_clockmod_table[0], target_freq, relation,
&newstate))
return -EINVAL;
freq =
((cpu_clock_freq / 1000) *
loongson2_clockmod_table[newstate].driver_data) / 8;
if (freq < policy->min || freq > policy->max)
return -EINVAL;
pr_debug("cpufreq: requested frequency %u Hz\n", target_freq * 1000);
freqs.old = loongson2_cpufreq_get(cpu);
freqs.new = freq;
freqs.flags = 0;
if (freqs.new == freqs.old)
return 0;
/* notifiers */
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
set_cpus_allowed_ptr(current, &cpus_allowed);
/* setting the cpu frequency */
clk_set_rate(cpuclk, freq);
/* notifiers */
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
pr_debug("cpufreq: set frequency %u kHz\n", freq);
return 0;
}
static int loongson2_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
int i;
unsigned long rate;
int ret;
cpuclk = clk_get(NULL, "cpu_clk");
if (IS_ERR(cpuclk)) {
printk(KERN_ERR "cpufreq: couldn't get CPU clk\n");
return PTR_ERR(cpuclk);
}
rate = cpu_clock_freq / 1000;
if (!rate) {
clk_put(cpuclk);
return -EINVAL;
}
/* clock table init */
for (i = 2;
(loongson2_clockmod_table[i].frequency != CPUFREQ_TABLE_END);
i++)
loongson2_clockmod_table[i].frequency = (rate * i) / 8;
ret = clk_set_rate(cpuclk, rate);
if (ret) {
clk_put(cpuclk);
return ret;
}
return cpufreq_generic_init(policy, &loongson2_clockmod_table[0], 0);
}
static int loongson2_cpufreq_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
clk_put(cpuclk);
return 0;
}
static struct cpufreq_driver loongson2_cpufreq_driver = {
.name = "loongson2",
.init = loongson2_cpufreq_cpu_init,
.verify = cpufreq_generic_frequency_table_verify,
.target = loongson2_cpufreq_target,
.get = loongson2_cpufreq_get,
.exit = loongson2_cpufreq_exit,
.attr = cpufreq_generic_attr,
};
static struct platform_device_id platform_device_ids[] = {
{
.name = "loongson2_cpufreq",
},
{}
};
MODULE_DEVICE_TABLE(platform, platform_device_ids);
static struct platform_driver platform_driver = {
.driver = {
.name = "loongson2_cpufreq",
.owner = THIS_MODULE,
},
.id_table = platform_device_ids,
};
/*
* This is the simple version of Loongson-2 wait, Maybe we need do this in
* interrupt disabled context.
*/
static DEFINE_SPINLOCK(loongson2_wait_lock);
static void loongson2_cpu_wait(void)
{
unsigned long flags;
u32 cpu_freq;
spin_lock_irqsave(&loongson2_wait_lock, flags);
cpu_freq = LOONGSON_CHIPCFG0;
LOONGSON_CHIPCFG0 &= ~0x7; /* Put CPU into wait mode */
LOONGSON_CHIPCFG0 = cpu_freq; /* Restore CPU state */
spin_unlock_irqrestore(&loongson2_wait_lock, flags);
local_irq_enable();
}
static int __init cpufreq_init(void)
{
int ret;
/* Register platform stuff */
ret = platform_driver_register(&platform_driver);
if (ret)
return ret;
pr_info("cpufreq: Loongson-2F CPU frequency driver.\n");
cpufreq_register_notifier(&loongson2_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
ret = cpufreq_register_driver(&loongson2_cpufreq_driver);
if (!ret && !nowait) {
saved_cpu_wait = cpu_wait;
cpu_wait = loongson2_cpu_wait;
}
return ret;
}
static void __exit cpufreq_exit(void)
{
if (!nowait && saved_cpu_wait)
cpu_wait = saved_cpu_wait;
cpufreq_unregister_driver(&loongson2_cpufreq_driver);
cpufreq_unregister_notifier(&loongson2_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
platform_driver_unregister(&platform_driver);
}
module_init(cpufreq_init);
module_exit(cpufreq_exit);
module_param(nowait, uint, 0644);
MODULE_PARM_DESC(nowait, "Disable Loongson-2F specific wait");
MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
MODULE_DESCRIPTION("cpufreq driver for Loongson2F");
MODULE_LICENSE("GPL");
|
