1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16#include <hardware_legacy/power.h>
17#include <fcntl.h>
18#include <errno.h>
19#include <stdlib.h>
20#include <stdio.h>
21#include <unistd.h>
22#include <errno.h>
23#include <string.h>
24#include <sys/stat.h>
25#include <sys/types.h>
26#include <pthread.h>
27
28#define LOG_TAG "power"
29#include <log/log.h>
30
31enum {
32    ACQUIRE_PARTIAL_WAKE_LOCK = 0,
33    RELEASE_WAKE_LOCK,
34    OUR_FD_COUNT
35};
36
37const char * const OLD_PATHS[] = {
38    "/sys/android_power/acquire_partial_wake_lock",
39    "/sys/android_power/release_wake_lock",
40};
41
42const char * const NEW_PATHS[] = {
43    "/sys/power/wake_lock",
44    "/sys/power/wake_unlock",
45};
46
47//XXX static pthread_once_t g_initialized = THREAD_ONCE_INIT;
48static int g_initialized = 0;
49static int g_fds[OUR_FD_COUNT];
50static int g_error = -1;
51
52static int
53open_file_descriptors(const char * const paths[])
54{
55    int i;
56    for (i=0; i<OUR_FD_COUNT; i++) {
57        int fd = open(paths[i], O_RDWR | O_CLOEXEC);
58        if (fd < 0) {
59            g_error = -errno;
60            fprintf(stderr, "fatal error opening \"%s\": %s\n", paths[i],
61                strerror(errno));
62            return -1;
63        }
64        g_fds[i] = fd;
65    }
66
67    g_error = 0;
68    return 0;
69}
70
71static inline void
72initialize_fds(void)
73{
74    // XXX: should be this:
75    //pthread_once(&g_initialized, open_file_descriptors);
76    // XXX: not this:
77    if (g_initialized == 0) {
78        if(open_file_descriptors(NEW_PATHS) < 0)
79            open_file_descriptors(OLD_PATHS);
80        g_initialized = 1;
81    }
82}
83
84int
85acquire_wake_lock(int lock, const char* id)
86{
87    initialize_fds();
88
89//    ALOGI("acquire_wake_lock lock=%d id='%s'\n", lock, id);
90
91    if (g_error) return g_error;
92
93    int fd;
94    size_t len;
95    ssize_t ret;
96
97    if (lock != PARTIAL_WAKE_LOCK) {
98        return -EINVAL;
99    }
100
101    fd = g_fds[ACQUIRE_PARTIAL_WAKE_LOCK];
102
103    ret = write(fd, id, strlen(id));
104    if (ret < 0) {
105        return -errno;
106    }
107
108    return ret;
109}
110
111int
112release_wake_lock(const char* id)
113{
114    initialize_fds();
115
116//    ALOGI("release_wake_lock id='%s'\n", id);
117
118    if (g_error) return g_error;
119
120    ssize_t len = write(g_fds[RELEASE_WAKE_LOCK], id, strlen(id));
121    if (len < 0) {
122        return -errno;
123    }
124    return len;
125}
126