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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
/*
* 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"
#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 *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);
}
}
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;
}
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;
}
|
