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      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 
     33 enum {
     34     ACQUIRE_PARTIAL_WAKE_LOCK = 0,
     35     RELEASE_WAKE_LOCK,
     36     OUR_FD_COUNT
     37 };
     38 
     39 const char * const OLD_PATHS[] = {
     40     "/sys/android_power/acquire_partial_wake_lock",
     41     "/sys/android_power/release_wake_lock",
     42 };
     43 
     44 const 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;
     50 static int g_initialized = 0;
     51 static int g_fds[OUR_FD_COUNT];
     52 static int g_error = 1;
     53 
     54 static 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 
     62 static int
     63 open_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 
     80 static inline void
     81 initialize_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 
     93 int
     94 acquire_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 
    114 int
    115 release_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