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/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define LOG_TAG "Tuna PowerHAL"
#include <utils/Log.h>
#include <hardware/hardware.h>
#include <hardware/power.h>
/*
* Tuna uses the legacy interface for requesting early suspend and late resume.
*/
#define LEGACY_SYS_POWER_STATE "/sys/power/state"
static int sPowerStatefd;
static const char *pwr_states[] = { "mem", "on" };
static void sysfs_write(char *path, char *s)
{
char buf[80];
int len;
int fd = open(path, O_WRONLY);
if (fd < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error opening %s: %s\n", path, buf);
return;
}
len = write(fd, s, strlen(s));
if (len < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", path, buf);
}
close(fd);
}
static void tuna_power_init(struct power_module *module)
{
char buf[80];
sPowerStatefd = open(LEGACY_SYS_POWER_STATE, O_RDWR);
if (sPowerStatefd < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error opening %s: %s\n", LEGACY_SYS_POWER_STATE, buf);
}
/*
* cpufreq interactive governor: timer 20ms, min sample 100ms,
* hispeed 700MHz at load 40%
*/
sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/timer_rate",
"20000");
sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/min_sample_time",
"100000");
sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/hispeed_freq",
"700000");
sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load",
"40");
}
static void tuna_power_set_interactive(struct power_module *module, int on)
{
char buf[80];
int len;
/*
* Lower maximum frequency when screen is off. CPU 0 and 1 share a
* cpufreq policy.
*/
sysfs_write("/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq",
on ? "1200000" : "700000");
len = write(sPowerStatefd, pwr_states[!!on], strlen(pwr_states[!!on]));
if (len < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", LEGACY_SYS_POWER_STATE, buf);
}
}
static struct hw_module_methods_t power_module_methods = {
.open = NULL,
};
struct power_module HAL_MODULE_INFO_SYM = {
.common = {
.tag = HARDWARE_MODULE_TAG,
.version_major = 1,
.version_minor = 0,
.id = POWER_HARDWARE_MODULE_ID,
.name = "Tuna Power HAL",
.author = "The Android Open Source Project",
.methods = &power_module_methods,
},
.init = tuna_power_init,
.setInteractive = tuna_power_set_interactive,
};
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