1 /*
2  * Copyright (C) 2008-2014 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 #ifndef ANDROID_SENSOR_BASE_H
18 #define ANDROID_SENSOR_BASE_H
19 
20 #include <errno.h>
21 #include <stdint.h>
22 #include <sys/cdefs.h>
23 #include <sys/types.h>
24 
25 
26 /*****************************************************************************/
27 
28 struct sensors_event_t;
29 
30 #define NS_PER_SEC 1000000000LL
31 #define NS_PER_US 1000
32 
33 class SensorBase {
34 protected:
35     const char* dev_name;
36     const char* data_name;
37     int         dev_fd;
38     int         data_fd;
39 
40     static int64_t getTimestamp();
41 
42 
timevalToNano(timeval const & t)43     static int64_t timevalToNano(timeval const& t) {
44         return t.tv_sec*NS_PER_SEC + t.tv_usec*NS_PER_US;
45     }
46 
47     int open_device();
48     int close_device();
49     int write_int(char const *path, int value);
50     int write_sys_attribute(
51     char const *path, char const *value, int bytes);
52 
53 public:
54             SensorBase(
55                     const char* dev_name,
56                     const char* data_name);
57 
58     virtual ~SensorBase();
59 
60     virtual int readEvents(sensors_event_t* data, int count) = 0;
61     virtual bool hasPendingEvents() const;
62     virtual int getFd() const;
getPollTime()63     virtual int getPollTime() { return -1; }
64     virtual int setDelay(int32_t handle, int64_t ns);
65     virtual int64_t getDelay(int32_t handle);
66 
67     // When this function is called, increments the reference counter.
68     virtual int setEnable(int32_t handle, int enabled) = 0;
69     // It returns the number of reference.
70     virtual int getEnable(int32_t handle) = 0;
71     virtual int batch(int handle, int flags, int64_t period_ns, int64_t timeout) = 0;
72     virtual int flush(int handle) = 0;
73 };
74 
75 /*****************************************************************************/
76 
77 #endif  // ANDROID_SENSOR_BASE_H
78