1 /*
2 * Copyright (C) 2013 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 <hardware/vibrator.h>
18 #include <hardware/hardware.h>
19
20 #include <cutils/log.h>
21
22 #include <stdio.h>
23 #include <unistd.h>
24 #include <fcntl.h>
25 #include <errno.h>
26 #include <math.h>
27
28 static const char THE_DEVICE[] = "/sys/class/timed_output/vibrator/enable";
29
vibra_exists()30 static int vibra_exists() {
31 int fd;
32
33 fd = TEMP_FAILURE_RETRY(open(THE_DEVICE, O_RDWR));
34 if(fd < 0) {
35 ALOGE("Vibrator file does not exist : %d", fd);
36 return 0;
37 }
38
39 close(fd);
40 return 1;
41 }
42
sendit(unsigned int timeout_ms)43 static int sendit(unsigned int timeout_ms)
44 {
45 int to_write, written, ret, fd;
46
47 char value[20]; /* large enough for millions of years */
48
49 fd = TEMP_FAILURE_RETRY(open(THE_DEVICE, O_RDWR));
50 if(fd < 0) {
51 return -errno;
52 }
53
54 to_write = snprintf(value, sizeof(value), "%u\n", timeout_ms);
55 written = TEMP_FAILURE_RETRY(write(fd, value, to_write));
56
57 if (written == -1) {
58 ret = -errno;
59 } else if (written != to_write) {
60 /* even though EAGAIN is an errno value that could be set
61 by write() in some cases, none of them apply here. So, this return
62 value can be clearly identified when debugging and suggests the
63 caller that it may try to call vibraror_on() again */
64 ret = -EAGAIN;
65 } else {
66 ret = 0;
67 }
68
69 errno = 0;
70 close(fd);
71
72 return ret;
73 }
74
vibra_on(vibrator_device_t * vibradev __unused,unsigned int timeout_ms)75 static int vibra_on(vibrator_device_t* vibradev __unused, unsigned int timeout_ms)
76 {
77 /* constant on, up to maximum allowed time */
78 return sendit(timeout_ms);
79 }
80
vibra_off(vibrator_device_t * vibradev __unused)81 static int vibra_off(vibrator_device_t* vibradev __unused)
82 {
83 return sendit(0);
84 }
85
vibra_close(hw_device_t * device)86 static int vibra_close(hw_device_t *device)
87 {
88 free(device);
89 return 0;
90 }
91
vibra_open(const hw_module_t * module,const char * id __unused,hw_device_t ** device __unused)92 static int vibra_open(const hw_module_t* module, const char* id __unused,
93 hw_device_t** device __unused) {
94 if (!vibra_exists()) {
95 ALOGE("Vibrator device does not exist. Cannot start vibrator");
96 return -ENODEV;
97 }
98
99 vibrator_device_t *vibradev = calloc(1, sizeof(vibrator_device_t));
100
101 if (!vibradev) {
102 ALOGE("Can not allocate memory for the vibrator device");
103 return -ENOMEM;
104 }
105
106 vibradev->common.tag = HARDWARE_DEVICE_TAG;
107 vibradev->common.module = (hw_module_t *) module;
108 vibradev->common.version = HARDWARE_DEVICE_API_VERSION(1,0);
109 vibradev->common.close = vibra_close;
110
111 vibradev->vibrator_on = vibra_on;
112 vibradev->vibrator_off = vibra_off;
113
114 *device = (hw_device_t *) vibradev;
115
116 return 0;
117 }
118
119 /*===========================================================================*/
120 /* Default vibrator HW module interface definition */
121 /*===========================================================================*/
122
123 static struct hw_module_methods_t vibrator_module_methods = {
124 .open = vibra_open,
125 };
126
127 struct hw_module_t HAL_MODULE_INFO_SYM = {
128 .tag = HARDWARE_MODULE_TAG,
129 .module_api_version = VIBRATOR_API_VERSION,
130 .hal_api_version = HARDWARE_HAL_API_VERSION,
131 .id = VIBRATOR_HARDWARE_MODULE_ID,
132 .name = "Default vibrator HAL",
133 .author = "The Android Open Source Project",
134 .methods = &vibrator_module_methods,
135 };
136