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 */
23 const int64_t kMaxDelay = 1000000000;
24 /* Gravitational acceleration constant in m/s^2 */
25 const float Sensor::kGravitationalAcceleration = 9.81f;
26 
Sensor()27 Sensor::Sensor() : acquisitionThread(nullptr), handle(-1), type(-1), delay(kMaxDelay) {}
28 
~Sensor()29 Sensor::~Sensor() {
30   if (acquisitionThread != nullptr) {
31     delete acquisitionThread;
32     acquisitionThread = nullptr;
33   }
34 }
35 
activate(int handle,int enabled)36 int Sensor::activate(int handle, int enabled) { return 0; }
37 
readOneEvent(sensors_event_t * event)38 bool 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 
activateAcquisitionThread(int pollFd,int handle,int enabled)66 int 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 
setDelay(int handle,int64_t requestedDelay)93 int 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 
batch(int handle,int flags,int64_t period_ns,int64_t timeout)111 int 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 
flush(int handle)117 int 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