autosuspend_earlysuspend.c revision a2582c2c4d20684b21aaf50913a27239789bf5eb 
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/types.h>
22#include <sys/stat.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 EARLYSUSPEND_SYS_POWER_STATE "/sys/power/state"
31#define EARLYSUSPEND_WAIT_FOR_FB_SLEEP "/sys/power/wait_for_fb_sleep"
32#define EARLYSUSPEND_WAIT_FOR_FB_WAKE "/sys/power/wait_for_fb_wake"
33
34
35static int sPowerStatefd;
36static const char *pwr_state_mem = "mem";
37static const char *pwr_state_on = "on";
38
39static int autosuspend_earlysuspend_enable(void)
40{
41    char buf[80];
42    int ret;
43
44    ALOGV("autosuspend_earlysuspend_enable\n");
45
46    ret = write(sPowerStatefd, pwr_state_mem, strlen(pwr_state_mem));
47    if (ret < 0) {
48        strerror_r(errno, buf, sizeof(buf));
49        ALOGE("Error writing to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
50        goto err;
51    }
52
53    ALOGV("autosuspend_earlysuspend_enable done\n");
54
55    return 0;
56
57err:
58    return ret;
59}
60
61static int autosuspend_earlysuspend_disable(void)
62{
63    char buf[80];
64    int ret;
65
66    ALOGV("autosuspend_earlysuspend_disable\n");
67
68    ret = write(sPowerStatefd, pwr_state_on, strlen(pwr_state_on));
69    if (ret < 0) {
70        strerror_r(errno, buf, sizeof(buf));
71        ALOGE("Error writing to %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
72        goto err;
73    }
74
75    ALOGV("autosuspend_earlysuspend_disable done\n");
76
77    return 0;
78
79err:
80    return ret;
81}
82
83struct autosuspend_ops autosuspend_earlysuspend_ops = {
84        .enable = autosuspend_earlysuspend_enable,
85        .disable = autosuspend_earlysuspend_disable,
86};
87
88struct autosuspend_ops *autosuspend_earlysuspend_init(void)
89{
90    char buf[80];
91    int ret;
92
93    ret = access(EARLYSUSPEND_WAIT_FOR_FB_SLEEP, F_OK);
94    if (ret < 0) {
95        return NULL;
96    }
97
98    ret = access(EARLYSUSPEND_WAIT_FOR_FB_WAKE, F_OK);
99    if (ret < 0) {
100        return NULL;
101    }
102
103    sPowerStatefd = open(EARLYSUSPEND_SYS_POWER_STATE, O_RDWR);
104
105    if (sPowerStatefd < 0) {
106        strerror_r(errno, buf, sizeof(buf));
107        ALOGE("Error opening %s: %s\n", EARLYSUSPEND_SYS_POWER_STATE, buf);
108        return NULL;
109    }
110
111    ALOGI("Selected early suspend\n");
112    return &autosuspend_earlysuspend_ops;
113}
114