1 /*
2  * Copyright (C) 2010 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_DEVICE_H
18 #define ANDROID_SENSOR_DEVICE_H
19 
20 #include <stdint.h>
21 #include <sys/types.h>
22 
23 #include <utils/KeyedVector.h>
24 #include <utils/Singleton.h>
25 #include <utils/String8.h>
26 
27 #include <gui/Sensor.h>
28 
29 // ---------------------------------------------------------------------------
30 
31 namespace android {
32 // ---------------------------------------------------------------------------
33 
34 class SensorDevice : public Singleton<SensorDevice> {
35     friend class Singleton<SensorDevice>;
36     sensors_poll_device_1_t* mSensorDevice;
37     struct sensors_module_t* mSensorModule;
38     static const nsecs_t MINIMUM_EVENTS_PERIOD =   1000000; // 1000 Hz
39     mutable Mutex mLock; // protect mActivationCount[].batchParams
40     // fixed-size array after construction
41 
42     // Struct to store all the parameters(samplingPeriod, maxBatchReportLatency and flags) from
43     // batch call. For continous mode clients, maxBatchReportLatency is set to zero.
44     struct BatchParams {
45       int flags;
46       nsecs_t batchDelay, batchTimeout;
BatchParamsBatchParams47       BatchParams() : flags(0), batchDelay(0), batchTimeout(0) {}
BatchParamsBatchParams48       BatchParams(int flag, nsecs_t delay, nsecs_t timeout): flags(flag), batchDelay(delay),
49           batchTimeout(timeout) { }
50       bool operator != (const BatchParams& other) {
51           return other.batchDelay != batchDelay || other.batchTimeout != batchTimeout ||
52                  other.flags != flags;
53       }
54     };
55 
56     // Store batch parameters in the KeyedVector and the optimal batch_rate and timeout in
57     // bestBatchParams. For every batch() call corresponding params are stored in batchParams
58     // vector. A continuous mode request is batch(... timeout=0 ..) followed by activate(). A batch
59     // mode request is batch(... timeout > 0 ...) followed by activate().
60     // Info is a per-sensor data structure which contains the batch parameters for each client that
61     // has registered for this sensor.
62     struct Info {
63         BatchParams bestBatchParams;
64         // Key is the unique identifier(ident) for each client, value is the batch parameters
65         // requested by the client.
66         KeyedVector<void*, BatchParams> batchParams;
67 
InfoInfo68         Info() : bestBatchParams(-1, -1, -1) {}
69         // Sets batch parameters for this ident. Returns error if this ident is not already present
70         // in the KeyedVector above.
71         status_t setBatchParamsForIdent(void* ident, int flags, int64_t samplingPeriodNs,
72                                         int64_t maxBatchReportLatencyNs);
73         // Finds the optimal parameters for batching and stores them in bestBatchParams variable.
74         void selectBatchParams();
75         // Removes batchParams for an ident and re-computes bestBatchParams. Returns the index of
76         // the removed ident. If index >=0, ident is present and successfully removed.
77         ssize_t removeBatchParamsForIdent(void* ident);
78     };
79     DefaultKeyedVector<int, Info> mActivationCount;
80 
81     SensorDevice();
82 public:
83     ssize_t getSensorList(sensor_t const** list);
84     status_t initCheck() const;
85     int getHalDeviceVersion() const;
86     ssize_t poll(sensors_event_t* buffer, size_t count);
87     status_t activate(void* ident, int handle, int enabled);
88     status_t batch(void* ident, int handle, int flags, int64_t samplingPeriodNs,
89                    int64_t maxBatchReportLatencyNs);
90     // Call batch with timeout zero instead of calling setDelay() for newer devices.
91     status_t setDelay(void* ident, int handle, int64_t ns);
92     status_t flush(void* ident, int handle);
93     void autoDisable(void *ident, int handle);
94     void dump(String8& result);
95 };
96 
97 // ---------------------------------------------------------------------------
98 }; // namespace android
99 
100 #endif // ANDROID_SENSOR_DEVICE_H
101