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/*
* Copyright (C) 2012 Freescale Semiconductor, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#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);
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