1 /*
2 * Copyright (C) 2012 Samsung
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 #define LOG_TAG "Sensors"
18
19 #include <fcntl.h>
20 #include <errno.h>
21 #include <cutils/log.h>
22 #include <pthread.h>
23
24 #include "IioSensorBase.h"
25
makeSysfsName(const char * input_name,const char * file_name)26 char *IioSensorBase::makeSysfsName(const char *input_name,
27 const char *file_name) {
28 char *name;
29 int ret;
30
31 ret = asprintf(&name, "/sys/bus/iio/devices/%s/%s", input_name, file_name);
32 if (ret < 0)
33 return NULL;
34
35 return name;
36 }
37
handleData(int value)38 void IioSensorBase::handleData(int value) {
39 }
40
IioSensorBase(const char * dev_name,const char * data_name,const char * enable_name,const char * chan_name,int iio_chan_type)41 IioSensorBase::IioSensorBase(const char *dev_name,
42 const char *data_name,
43 const char *enable_name,
44 const char *chan_name,
45 int iio_chan_type)
46 : SensorBase(dev_name, data_name),
47 mEnabled(true),
48 mHasPendingEvent(false),
49 mInputReader(MAX_BUFFER_FOR_EVENT),
50 mIioChanType(iio_chan_type),
51 mIioSysfsChanFp(NULL)
52 {
53 pthread_mutex_init(&mLock, NULL);
54 ALOGV("%s(): dev_name=%s", __func__, dev_name);
55 mPendingEvent.version = sizeof(sensors_event_t);
56 memset(mPendingEvent.data, 0, sizeof(mPendingEvent.data));
57 if (!mDataFd)
58 return;
59
60 mInputSysfsEnable = makeSysfsName(mInputName, enable_name);
61 if (!mInputSysfsEnable) {
62 ALOGE("%s: unable to allocate mem for %s:%s", __func__,
63 data_name, enable_name);
64 return;
65 }
66 mInputSysfsSamplingFrequency = makeSysfsName(mInputName, "sampling_frequency");
67 if (!mInputSysfsSamplingFrequency) {
68 ALOGE("%s: unable to allocate mem for %s:poll_delay", __func__,
69 data_name);
70 return;
71 }
72
73 mIioSysfsChan = makeSysfsName(mInputName, chan_name);
74 if (!mIioSysfsChan) {
75 ALOGE("%s: unable to allocate mem for %s:%s", __func__, data_name,
76 chan_name);
77 return;
78 }
79
80 mIioSysfsChanFp = fopen(mIioSysfsChan, "r");
81 if (mIioSysfsChanFp == NULL) {
82 ALOGE("%s: unable to open %s", __func__, mIioSysfsChan);
83 return;
84 }
85
86 int flags = fcntl(mDataFd, F_GETFL, 0);
87 fcntl(mDataFd, F_SETFL, flags | O_NONBLOCK);
88
89 enable(0, 0);
90 }
91
~IioSensorBase()92 IioSensorBase::~IioSensorBase() {
93 if (mEnabled) {
94 enable(0, 0);
95 }
96 if (mIioSysfsChanFp != NULL) {
97 fclose(mIioSysfsChanFp);
98 }
99 free(mInputSysfsEnable);
100 free(mInputSysfsSamplingFrequency);
101 free(mIioSysfsChan);
102 }
103
readValue(int * value)104 bool IioSensorBase::readValue(int *value) {
105
106 bool ret = true;
107
108 if (mIioSysfsChanFp == NULL)
109 return false;
110
111 if (fscanf(mIioSysfsChanFp, "%d\n", value) != 1)
112 ret = false;
113
114 fseek(mIioSysfsChanFp, 0, SEEK_SET);
115
116 return ret;
117 }
118
enable(int32_t handle,int en)119 int IioSensorBase::enable(int32_t handle, int en)
120 {
121 int err = 0;
122
123 ALOGI("%s: %s %d", __func__, mDevName, en);
124
125 pthread_mutex_lock(&mLock);
126 if (en != mEnabled) {
127 int fd;
128 fd = open(mInputSysfsEnable, O_RDWR);
129 if (fd >= 0) {
130 err = write(fd, en ? "1" : "0", 2);
131 close(fd);
132 if (err < 0) {
133 goto cleanup;
134 }
135 mEnabled = en;
136 err = 0;
137 } else {
138 err = -1;
139 }
140 }
141 cleanup:
142 pthread_mutex_unlock(&mLock);
143 return err;
144 }
145
setDelay(int32_t handle,int64_t ns)146 int IioSensorBase::setDelay(int32_t handle, int64_t ns)
147 {
148 int fd;
149 int result = 0;
150 char buf[21]; /* 21 = log10(max long long int) + 1 for sign + '\0' */
151 pthread_mutex_lock(&mLock);
152 if (!ns) {
153 result = -1;
154 goto done;
155 }
156 fd = open(mInputSysfsSamplingFrequency, O_RDWR);
157 if (fd < 0) {
158 result = -1;
159 goto done;
160 }
161 /* round up ((NSEC_PER_SEC - 1) + ns) / ns */
162 sprintf(buf, "%lld", ((1000000000 - 1) + ns) / ns);
163 write(fd, buf, strlen(buf)+1);
164 close(fd);
165 done:
166 pthread_mutex_unlock(&mLock);
167 return result;
168 }
169
readEvents(sensors_event_t * data,int count)170 int IioSensorBase::readEvents(sensors_event_t* data, int count)
171 {
172 if (count < 1)
173 return -EINVAL;
174
175 pthread_mutex_lock(&mLock);
176 int numEventReceived = 0;
177
178 if (mHasPendingEvent) {
179 mHasPendingEvent = false;
180 if (mEnabled) {
181 mPendingEvent.timestamp = getTimestamp();
182 *data = mPendingEvent;
183 numEventReceived++;
184 }
185 goto done;
186 }
187
188 iio_event_data const* event;
189
190 while (count && mInputReader.readEvent(mDataFd, &event)) {
191 int value;
192 if (IIO_EVENT_CODE_EXTRACT_CHAN_TYPE(event->id) == mIioChanType) {
193 if (mEnabled && readValue(&value)) {
194 handleData(value);
195 mPendingEvent.timestamp = event->timestamp;
196 *data++ = mPendingEvent;
197 count--;
198 numEventReceived++;
199 }
200 }
201 mInputReader.next();
202 }
203
204 done:
205 pthread_mutex_unlock(&mLock);
206 return numEventReceived;
207 }
208