1/*
2 * Copyright (C) 2015 Intel Corporation
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 <cutils/log.h>
18#include <hardware/sensors.h>
19#include <errno.h>
20#include "Sensor.hpp"
21
22/* maximum delay: 1000ms */
23const int64_t kMaxDelay = 1000000000;
24/* Gravitational acceleration constant in m/s^2 */
25const float Sensor::kGravitationalAcceleration = 9.81f;
26
27Sensor::Sensor() : acquisitionThread(nullptr), handle(-1), type(-1), delay(kMaxDelay) {}
28
29Sensor::~Sensor() {
30  if (acquisitionThread != nullptr) {
31    delete acquisitionThread;
32    acquisitionThread = nullptr;
33  }
34}
35
36int Sensor::activate(int handle, int enabled) { return 0; }
37
38bool Sensor::readOneEvent(sensors_event_t *event) {
39  int bytes_read = 0, bytes_to_read = sizeof(sensors_event_t);
40  int fd = -1;
41  char *ptr = (char *)event;
42
43  if (acquisitionThread == nullptr) {
44    ALOGE("%s: sensor %d doesn't have an acquisition thread", __func__, handle);
45    return false;
46  }
47
48  /* read one event from the pipe read endpoint */
49  fd = acquisitionThread->getReadPipeFd();
50  do {
51    bytes_read = read(fd, ptr, bytes_to_read);
52    if (bytes_read <= 0) {
53      break;
54    }
55    bytes_to_read -= bytes_read;
56    ptr += bytes_read;
57  } while (bytes_to_read > 0);
58
59  if (bytes_to_read != 0) {
60    return false;
61  }
62
63  return true;
64}
65
66int Sensor::activateAcquisitionThread(int pollFd, int handle, int enabled) {
67  if (enabled) {
68    /* create/init acquisition thread if necessary */
69    if (acquisitionThread == nullptr) {
70      acquisitionThread = new AcquisitionThread(pollFd, this);
71      if (!acquisitionThread->init()) {
72        ALOGE("%s: Cannot initialize acquisition thread for sensor %d",
73            __func__, handle);
74        delete acquisitionThread;
75        acquisitionThread = nullptr;
76        return -1;
77      }
78    } else {
79      ALOGE("%s: Sensor %d is already enabled", __func__, handle);
80    }
81  } else {
82    /* free acquisition thread resources */
83    if (acquisitionThread != nullptr) {
84      delete acquisitionThread;
85      acquisitionThread = nullptr;
86    } else {
87      ALOGE("%s: Sensor %d is already disabled", __func__, handle);
88    }
89  }
90  return 0;
91}
92
93int Sensor::setDelay(int handle, int64_t requestedDelay) {
94  if (requestedDelay < 0) {
95    return -EINVAL;
96  }
97
98  if (requestedDelay > kMaxDelay) {
99    requestedDelay = kMaxDelay;
100  }
101
102  this->delay = requestedDelay;
103  /* wake up thread to immediately change the delay */
104  if (acquisitionThread != nullptr) {
105    return acquisitionThread->wakeup();
106  }
107
108  return 0;
109}
110
111int Sensor::batch(int handle, int flags,
112                      int64_t period_ns, int64_t timeout) {
113  /* batching mode is not supported; call setDelay */
114  return setDelay(handle, period_ns);
115}
116
117int Sensor::flush(int handle) {
118  if (acquisitionThread == nullptr) {
119    return -EINVAL;
120  }
121
122  /* batching mode is not supported; generate META_DATA_FLUSH_COMPLETE */
123  if (acquisitionThread->generateFlushCompleteEvent()) {
124    return 0;
125  }
126
127  return -1;
128}
129