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 <sys/time.h>
23#include <time.h>
24#include <errno.h>
25#include <string.h>
26#include <sys/stat.h>
27#include <sys/types.h>
28#include <pthread.h>
29
30#define LOG_TAG "power"
31#include <utils/Log.h>
32
33enum {
34    ACQUIRE_PARTIAL_WAKE_LOCK = 0,
35    RELEASE_WAKE_LOCK,
36    OUR_FD_COUNT
37};
38
39const char * const OLD_PATHS[] = {
40    "/sys/android_power/acquire_partial_wake_lock",
41    "/sys/android_power/release_wake_lock",
42};
43
44const char * const NEW_PATHS[] = {
45    "/sys/power/wake_lock",
46    "/sys/power/wake_unlock",
47};
48
49//XXX static pthread_once_t g_initialized = THREAD_ONCE_INIT;
50static int g_initialized = 0;
51static int g_fds[OUR_FD_COUNT];
52static int g_error = 1;
53
54static int64_t systemTime()
55{
56    struct timespec t;
57    t.tv_sec = t.tv_nsec = 0;
58    clock_gettime(CLOCK_MONOTONIC, &t);
59    return t.tv_sec*1000000000LL + t.tv_nsec;
60}
61
62static int
63open_file_descriptors(const char * const paths[])
64{
65    int i;
66    for (i=0; i<OUR_FD_COUNT; i++) {
67        int fd = open(paths[i], O_RDWR);
68        if (fd < 0) {
69            fprintf(stderr, "fatal error opening \"%s\"\n", paths[i]);
70            g_error = errno;
71            return -1;
72        }
73        g_fds[i] = fd;
74    }
75
76    g_error = 0;
77    return 0;
78}
79
80static inline void
81initialize_fds(void)
82{
83    // XXX: should be this:
84    //pthread_once(&g_initialized, open_file_descriptors);
85    // XXX: not this:
86    if (g_initialized == 0) {
87        if(open_file_descriptors(NEW_PATHS) < 0)
88            open_file_descriptors(OLD_PATHS);
89        g_initialized = 1;
90    }
91}
92
93int
94acquire_wake_lock(int lock, const char* id)
95{
96    initialize_fds();
97
98//    ALOGI("acquire_wake_lock lock=%d id='%s'\n", lock, id);
99
100    if (g_error) return g_error;
101
102    int fd;
103
104    if (lock == PARTIAL_WAKE_LOCK) {
105        fd = g_fds[ACQUIRE_PARTIAL_WAKE_LOCK];
106    }
107    else {
108        return EINVAL;
109    }
110
111    return write(fd, id, strlen(id));
112}
113
114int
115release_wake_lock(const char* id)
116{
117    initialize_fds();
118
119//    ALOGI("release_wake_lock id='%s'\n", id);
120
121    if (g_error) return g_error;
122
123    ssize_t len = write(g_fds[RELEASE_WAKE_LOCK], id, strlen(id));
124    return len >= 0;
125}
126