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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 <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <stddef.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#define LOG_TAG "libsuspend"
//#define LOG_NDEBUG 0
#include <cutils/log.h>
#include "autosuspend_ops.h"
#define SYS_POWER_STATE "/sys/power/state"
#define SYS_POWER_WAKEUP_COUNT "/sys/power/wakeup_count"
static int state_fd;
static int wakeup_count_fd;
static pthread_t suspend_thread;
static sem_t suspend_lockout;
static const char *sleep_state = "mem";
static void (*wakeup_func)(void) = NULL;
static void *suspend_thread_func(void *arg __attribute__((unused)))
{
char buf[80];
char wakeup_count[20];
int wakeup_count_len;
int ret;
while (1) {
usleep(100000);
ALOGV("%s: read wakeup_count\n", __func__);
lseek(wakeup_count_fd, 0, SEEK_SET);
wakeup_count_len = read(wakeup_count_fd, wakeup_count, sizeof(wakeup_count));
if (wakeup_count_len < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error reading from %s: %s\n", SYS_POWER_WAKEUP_COUNT, buf);
wakeup_count_len = 0;
continue;
}
if (!wakeup_count_len) {
ALOGE("Empty wakeup count\n");
continue;
}
ALOGV("%s: wait\n", __func__);
ret = sem_wait(&suspend_lockout);
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error waiting on semaphore: %s\n", buf);
continue;
}
ALOGV("%s: write %*s to wakeup_count\n", __func__, wakeup_count_len, wakeup_count);
ret = write(wakeup_count_fd, wakeup_count, wakeup_count_len);
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", SYS_POWER_WAKEUP_COUNT, buf);
} else {
ALOGV("%s: write %s to %s\n", __func__, sleep_state, SYS_POWER_STATE);
ret = write(state_fd, sleep_state, strlen(sleep_state));
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", SYS_POWER_STATE, buf);
} else {
void (*func)(void) = wakeup_func;
if (func != NULL) {
(*func)();
}
}
}
ALOGV("%s: release sem\n", __func__);
ret = sem_post(&suspend_lockout);
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error releasing semaphore: %s\n", buf);
}
}
return NULL;
}
static int autosuspend_wakeup_count_enable(void)
{
char buf[80];
int ret;
ALOGV("autosuspend_wakeup_count_enable\n");
ret = sem_post(&suspend_lockout);
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error changing semaphore: %s\n", buf);
}
ALOGV("autosuspend_wakeup_count_enable done\n");
return ret;
}
static int autosuspend_wakeup_count_disable(void)
{
char buf[80];
int ret;
ALOGV("autosuspend_wakeup_count_disable\n");
ret = sem_wait(&suspend_lockout);
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error changing semaphore: %s\n", buf);
}
ALOGV("autosuspend_wakeup_count_disable done\n");
return ret;
}
void set_wakeup_callback(void (*func)(void))
{
if (wakeup_func != NULL) {
ALOGE("Duplicate wakeup callback applied, keeping original");
return;
}
wakeup_func = func;
}
struct autosuspend_ops autosuspend_wakeup_count_ops = {
.enable = autosuspend_wakeup_count_enable,
.disable = autosuspend_wakeup_count_disable,
};
struct autosuspend_ops *autosuspend_wakeup_count_init(void)
{
int ret;
char buf[80];
state_fd = open(SYS_POWER_STATE, O_RDWR);
if (state_fd < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error opening %s: %s\n", SYS_POWER_STATE, buf);
goto err_open_state;
}
wakeup_count_fd = open(SYS_POWER_WAKEUP_COUNT, O_RDWR);
if (wakeup_count_fd < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error opening %s: %s\n", SYS_POWER_WAKEUP_COUNT, buf);
goto err_open_wakeup_count;
}
ret = sem_init(&suspend_lockout, 0, 0);
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error creating semaphore: %s\n", buf);
goto err_sem_init;
}
ret = pthread_create(&suspend_thread, NULL, suspend_thread_func, NULL);
if (ret) {
strerror_r(ret, buf, sizeof(buf));
ALOGE("Error creating thread: %s\n", buf);
goto err_pthread_create;
}
ALOGI("Selected wakeup count\n");
return &autosuspend_wakeup_count_ops;
err_pthread_create:
sem_destroy(&suspend_lockout);
err_sem_init:
close(wakeup_count_fd);
err_open_wakeup_count:
close(state_fd);
err_open_state:
return NULL;
}
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