autosuspend_autosleep.c revision b98865586bcf7779150c461b64e4fe49972f6351 
1/*
2 * Copyright (C) 2012 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
17#include <errno.h>
18#include <fcntl.h>
19#include <stddef.h>
20#include <string.h>
21#include <sys/stat.h>
22#include <sys/types.h>
23#include <unistd.h>
24
25#define LOG_TAG "libsuspend"
26#include <cutils/log.h>
27
28#include "autosuspend_ops.h"
29
30#define SYS_POWER_AUTOSLEEP "/sys/power/autosleep"
31
32static int autosleep_fd;
33static const char *sleep_state = "mem";
34static const char *on_state = "off";
35
36static int autosuspend_autosleep_enable(void)
37{
38    char buf[80];
39    int ret;
40
41    ALOGV("autosuspend_autosleep_enable\n");
42
43    ret = write(autosleep_fd, sleep_state, strlen(sleep_state));
44    if (ret < 0) {
45        strerror_r(errno, buf, sizeof(buf));
46        ALOGE("Error writing to %s: %s\n", SYS_POWER_AUTOSLEEP, buf);
47        goto err;
48    }
49
50    ALOGV("autosuspend_autosleep_enable done\n");
51
52    return 0;
53
54err:
55    return ret;
56}
57
58static int autosuspend_autosleep_disable(void)
59{
60    char buf[80];
61    int ret;
62
63    ALOGV("autosuspend_autosleep_disable\n");
64
65    ret = write(autosleep_fd, on_state, strlen(on_state));
66    if (ret < 0) {
67        strerror_r(errno, buf, sizeof(buf));
68        ALOGE("Error writing to %s: %s\n", SYS_POWER_AUTOSLEEP, buf);
69        goto err;
70    }
71
72    ALOGV("autosuspend_autosleep_disable done\n");
73
74    return 0;
75
76err:
77    return ret;
78}
79
80struct autosuspend_ops autosuspend_autosleep_ops = {
81        .enable = autosuspend_autosleep_enable,
82        .disable = autosuspend_autosleep_disable,
83};
84
85struct autosuspend_ops *autosuspend_autosleep_init(void)
86{
87    int ret;
88    char buf[80];
89
90    autosleep_fd = open(SYS_POWER_AUTOSLEEP, O_WRONLY);
91    if (autosleep_fd < 0) {
92        strerror_r(errno, buf, sizeof(buf));
93        ALOGE("Error opening %s: %s\n", SYS_POWER_AUTOSLEEP, buf);
94        return NULL;
95    }
96
97    ALOGI("Selected autosleep\n");
98
99    autosuspend_autosleep_disable();
100
101    return &autosuspend_autosleep_ops;
102}
103