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      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;
     47       BatchParams() : flags(0), batchDelay(0), batchTimeout(0) {}
     48       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 
     68         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