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