blob: 3793a699ede29d81bbad220caf3db8f47546e0d1 [file] [log] [blame] [edit]
/*
* 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 <stdbool.h>
#include <stddef.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#define LOG_TAG "libsuspend"
#include <cutils/log.h>
#include "autosuspend_ops.h"
#define EARLYSUSPEND_SYS_POWER_STATE "/sys/power/state"
#define EARLYSUSPEND_WAIT_FOR_FB_SLEEP "/sys/power/wait_for_fb_sleep"
#define EARLYSUSPEND_WAIT_FOR_FB_WAKE "/sys/power/wait_for_fb_wake"
static int sPowerStatefd;
static const char *pwr_state_mem = "mem";
static const char *pwr_state_on = "on";
static pthread_t earlysuspend_thread;
static pthread_mutex_t earlysuspend_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t earlysuspend_cond = PTHREAD_COND_INITIALIZER;
static bool wait_for_earlysuspend;
static enum {
EARLYSUSPEND_ON,
EARLYSUSPEND_MEM,
} earlysuspend_state = EARLYSUSPEND_ON;
int wait_for_fb_wake(void)
{
int err = 0;
char buf;
int fd = TEMP_FAILURE_RETRY(open(EARLYSUSPEND_WAIT_FOR_FB_WAKE, O_RDONLY, 0));
// if the file doesn't exist, the error will be caught in read() below
err = TEMP_FAILURE_RETRY(read(fd, &buf, 1));
ALOGE_IF(err < 0,
"*** ANDROID_WAIT_FOR_FB_WAKE failed (%s)", strerror(errno));
close(fd);
return err < 0 ? err : 0;
}
static int wait_for_fb_sleep(void)
{
int err = 0;
char buf;
int fd = TEMP_FAILURE_RETRY(open(EARLYSUSPEND_WAIT_FOR_FB_SLEEP, O_RDONLY, 0));
// if the file doesn't exist, the error will be caught in read() below
err = TEMP_FAILURE_RETRY(read(fd, &buf, 1));
ALOGE_IF(err < 0,
"*** ANDROID_WAIT_FOR_FB_SLEEP failed (%s)", strerror(errno));
close(fd);
return err < 0 ? err : 0;
}
static void *earlysuspend_thread_func(void __unused *arg)
{
while (1) {
if (wait_for_fb_sleep()) {
ALOGE("Failed reading wait_for_fb_sleep, exiting earlysuspend thread\n");
return NULL;
}
pthread_mutex_lock(&earlysuspend_mutex);
earlysuspend_state = EARLYSUSPEND_MEM;
pthread_cond_signal(&earlysuspend_cond);
pthread_mutex_unlock(&earlysuspend_mutex);
if (wait_for_fb_wake()) {
ALOGE("Failed reading wait_for_fb_wake, exiting earlysuspend thread\n");
return NULL;
}
pthread_mutex_lock(&earlysuspend_mutex);
earlysuspend_state = EARLYSUSPEND_ON;
pthread_cond_signal(&earlysuspend_cond);
pthread_mutex_unlock(&earlysuspend_mutex);
}
}
static int autosuspend_earlysuspend_enable(void)
{
char buf[80];
int ret;
ALOGV("autosuspend_earlysuspend_enable\n");
ret = write(sPowerStatefd, pwr_state_mem, strlen(pwr_state_mem));
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
goto err;
}
if (wait_for_earlysuspend) {
pthread_mutex_lock(&earlysuspend_mutex);
while (earlysuspend_state != EARLYSUSPEND_MEM) {
pthread_cond_wait(&earlysuspend_cond, &earlysuspend_mutex);
}
pthread_mutex_unlock(&earlysuspend_mutex);
}
ALOGV("autosuspend_earlysuspend_enable done\n");
return 0;
err:
return ret;
}
static int autosuspend_earlysuspend_disable(void)
{
char buf[80];
int ret;
ALOGV("autosuspend_earlysuspend_disable\n");
ret = TEMP_FAILURE_RETRY(write(sPowerStatefd, pwr_state_on, strlen(pwr_state_on)));
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
goto err;
}
if (wait_for_earlysuspend) {
pthread_mutex_lock(&earlysuspend_mutex);
while (earlysuspend_state != EARLYSUSPEND_ON) {
pthread_cond_wait(&earlysuspend_cond, &earlysuspend_mutex);
}
pthread_mutex_unlock(&earlysuspend_mutex);
}
ALOGV("autosuspend_earlysuspend_disable done\n");
return 0;
err:
return ret;
}
struct autosuspend_ops autosuspend_earlysuspend_ops = {
.enable = autosuspend_earlysuspend_enable,
.disable = autosuspend_earlysuspend_disable,
};
void start_earlysuspend_thread(void)
{
char buf[80];
int ret;
ret = access(EARLYSUSPEND_WAIT_FOR_FB_SLEEP, F_OK);
if (ret < 0) {
return;
}
ret = access(EARLYSUSPEND_WAIT_FOR_FB_WAKE, F_OK);
if (ret < 0) {
return;
}
wait_for_fb_wake();
ALOGI("Starting early suspend unblocker thread\n");
ret = pthread_create(&earlysuspend_thread, NULL, earlysuspend_thread_func, NULL);
if (ret) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error creating thread: %s\n", buf);
return;
}
wait_for_earlysuspend = true;
}
struct autosuspend_ops *autosuspend_earlysuspend_init(void)
{
char buf[80];
int ret;
sPowerStatefd = TEMP_FAILURE_RETRY(open(EARLYSUSPEND_SYS_POWER_STATE, O_RDWR));
if (sPowerStatefd < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGW("Error opening %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
return NULL;
}
ret = TEMP_FAILURE_RETRY(write(sPowerStatefd, "on", 2));
if (ret < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGW("Error writing 'on' to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
goto err_write;
}
ALOGI("Selected early suspend\n");
start_earlysuspend_thread();
return &autosuspend_earlysuspend_ops;
err_write:
close(sPowerStatefd);
return NULL;
}