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
|
/*
* Copyright (C)2012 Freescale Semiconductor, Inc. All Rights Reserved.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/fs.h>
#include <linux/earlysuspend.h>
#include <linux/cpufreq.h>
void cpufreq_save_default_governor(void);
void cpufreq_restore_default_governor(void);
void cpufreq_set_conservative_governor(void);
void cpufreq_set_conservative_governor_param(int up_th, int down_th);
#define SET_CONSERVATIVE_GOVERNOR_UP_THRESHOLD 95
#define SET_CONSERVATIVE_GOVERNOR_DOWN_THRESHOLD 50
static char cpufreq_gov_default[32];
static char *cpufreq_gov_conservative = "conservative";
static char *cpufreq_sysfs_place_holder = "/sys/devices/system/cpu/cpu%i/cpufreq/scaling_governor";
static char *cpufreq_gov_conservative_param = "/sys/devices/system/cpu/cpufreq/conservative/%s";
static void cpufreq_set_governor(char *governor)
{
struct file *scaling_gov = NULL;
char buf[128];
int i;
loff_t offset = 0;
if (governor == NULL)
return;
for_each_online_cpu(i) {
sprintf(buf, cpufreq_sysfs_place_holder, i);
scaling_gov = filp_open(buf, O_RDWR, 0);
if (scaling_gov != NULL) {
if (scaling_gov->f_op != NULL &&
scaling_gov->f_op->write != NULL)
scaling_gov->f_op->write(scaling_gov,
governor,
strlen(governor),
&offset);
else
pr_err("f_op might be null\n");
filp_close(scaling_gov, NULL);
} else {
pr_err("%s. Can't open %s\n", __func__, buf);
}
}
}
void cpufreq_save_default_governor(void)
{
int ret;
struct cpufreq_policy current_policy;
ret = cpufreq_get_policy(¤t_policy, 0);
if (ret < 0)
pr_err("%s: cpufreq_get_policy got error", __func__);
memcpy(cpufreq_gov_default, current_policy.governor->name, 32);
}
void cpufreq_restore_default_governor(void)
{
cpufreq_set_governor(cpufreq_gov_default);
}
void cpufreq_set_conservative_governor_param(int up_th, int down_th)
{
struct file *gov_param = NULL;
static char buf[128], parm[8];
loff_t offset = 0;
if (up_th <= down_th) {
printk(KERN_ERR "%s: up_th(%d) is lesser than down_th(%d)\n",
__func__, up_th, down_th);
return;
}
sprintf(parm, "%d", up_th);
sprintf(buf, cpufreq_gov_conservative_param , "up_threshold");
gov_param = filp_open(buf, O_RDONLY, 0);
if (gov_param != NULL) {
if (gov_param->f_op != NULL &&
gov_param->f_op->write != NULL)
gov_param->f_op->write(gov_param,
parm,
strlen(parm),
&offset);
else
pr_err("f_op might be null\n");
filp_close(gov_param, NULL);
} else {
pr_err("%s. Can't open %s\n", __func__, buf);
}
sprintf(parm, "%d", down_th);
sprintf(buf, cpufreq_gov_conservative_param , "down_threshold");
gov_param = filp_open(buf, O_RDONLY, 0);
if (gov_param != NULL) {
if (gov_param->f_op != NULL &&
gov_param->f_op->write != NULL)
gov_param->f_op->write(gov_param,
parm,
strlen(parm),
&offset);
else
pr_err("f_op might be null\n");
filp_close(gov_param, NULL);
} else {
pr_err("%s. Can't open %s\n", __func__, buf);
}
}
static void cpufreq_early_suspend(struct early_suspend *p)
{
cpufreq_save_default_governor();
cpufreq_set_conservative_governor();
cpufreq_set_conservative_governor_param(
SET_CONSERVATIVE_GOVERNOR_UP_THRESHOLD,
SET_CONSERVATIVE_GOVERNOR_DOWN_THRESHOLD);
}
static void cpufreq_late_resume(struct early_suspend *p)
{
cpufreq_restore_default_governor();
}
struct early_suspend cpufreq_earlysuspend = {
.level = EARLY_SUSPEND_LEVEL_POST_DISABLE_FB,
.suspend = cpufreq_early_suspend,
.resume = cpufreq_late_resume,
};
void cpufreq_set_conservative_governor(void)
{
cpufreq_set_governor(cpufreq_gov_conservative);
}
static int __init cpufreq_on_earlysuspend_init(void)
{
register_early_suspend(&cpufreq_earlysuspend);
return 0;
}
static void __exit cpufreq_on_earlysuspend_exit(void)
{
unregister_early_suspend(&cpufreq_earlysuspend);
}
module_init(cpufreq_on_earlysuspend_init);
module_exit(cpufreq_on_earlysuspend_exit);
|
