GPS_Provider Library

File content as of revision 4:193bf97d4c5a:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2014 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __GPS_PROVIDER_H__
#define __GPS_PROVIDER_H__

// [ST-GNSS] - Geofencing API
class GPSGeofence; /* forward declaration */
// [ST-GNSS] - Datalogging API
class GPSDatalog; /* forward declaration */

class GPSProviderImplBase; /* forward declaration */
extern GPSProviderImplBase *createGPSProviderInstance(void);


//
// Here's a snippet showing how this API can be used. The handler gets invoked
// from thread context--i.e. from the main application.
//
//      void handleGPSData(const LocationUpdateParams_t *newLocation) {
//          ...
//      }
//
//      GPSProvider gps;
//
//      gps.setPowerMode(LOW_POWER);
//      gps.onLocationUpdate(handleGPSData);
//
//      gps.reset();
//      gps.start();
//
//      while (true) {
//          /* purely optional */
//          static bool printedDeviceInfo = false;
//          if (!printedDeviceInfo && gps.haveDeviceInfo()) {
//              printf("%s", gps.getDeviceInfo());
//              printedDeviceInfo = true;
//          }
//
//          /* Main message processing activity; location callbacks are called
//           * as a result of message processing. */
//          gps.process();
//          /* sleep(); */
//
//          if (/* at some point in the future */) {
//              break;
//          }
//      }
//      gps.stop();
//

class GPSProvider {
  
public:
    /** Power mode selection */
    enum PowerMode_t {
         POWER_FULL, /**< full-power mode typically results in high-accuracy location data updated at 1Hz. */
         POWER_LOW,  /**< low-power mode involves longer periods of hibernation in between location updates. */
    };

    /**
     * GPS time starts from UTC 01/06/1980(MM/DD/YYYY) and includes 2 fields:
     * week and tow. For a given GPS time, week is the passed week number since
     * the GPS start time, and tow(time of week) is the passed seconds since the
     * last Sunday. For example, a given UTC time [10/30/3014
     * 01:10:00](MM/DD/YYYY HH:MM:SS) can be converted into GPS time [1816,
     * 4200](week, seconds).
     *
     * GPS time can be used as a quite accurate time once position is fixed.
     */
    struct GPSTime_t {
        uint16_t gps_week;
        uint32_t tow;       /* time of week (in millisecond) */
    };

    typedef double LocationType_t;
    typedef float Altitude_t;
    struct LocationUpdateParams_t {
        uint32_t       version; /* Layout-version for the following structure;
                                 * this is to accommodate changes over time. */
        bool           valid;   /* Does this update contain a valid location. */
        LocationType_t lat;
        LocationType_t lon;
        Altitude_t     altitude;

        unsigned       numGPSSVs; /* num GPS Satellites */
        unsigned       numGLOSVs; /* num GLONASS Satellites */

        GPSTime_t      gpsTime; /* gps time */
        uint64_t       utcTime; /* UTC time in millisecond */
    };

    /** [ST-GNSS] - Geofencing API */
    struct Timestamp_t {
      int hh;  /**< Hours */
      int mm;  /**< Minutes */
      int ss;  /**< Seconds */
      int year;  /**< Year */
      int month;  /**< Month */
      int day;  /**< Day */
    };
    
    struct GeofenceStatusParams_t {
      Timestamp_t timestamp;
      int *currentStatus;
      int numGeofences;
      int idAlarm;
    };
    
    /** [ST-GNSS] - Datalogging API */
    struct LogStatusParams_t {
      Timestamp_t firstEntryTimestamp;
      Timestamp_t lastEntryTimestamp;
      unsigned usedEntries;
      uint8_t bufferStatus;
      unsigned remainingFreeEntries;
    };

    /** [ST-GNSS] - Datalogging API */
    struct LogQueryParams_t {
      Timestamp_t startTimestamp;
      unsigned entries;
    };

    /** [ST-GNSS] - Datalogging API */
    struct LogQueryRespParams_t {
      uint8_t statusBitmap;
      uint8_t logMask;
      Timestamp_t timestamp;
      uint8_t fix;
      unsigned quality;
      uint8_t geo;
      LocationType_t lat;
      LocationType_t lon;
      Altitude_t altitude;
      double speed;
      double odo;
    };

    // [ST-GNSS] - Odometer API
    struct OdoParams_t {
      Timestamp_t timestamp;
      unsigned odoA;
      unsigned odoB;
      unsigned odoPon;
    };
    
public:
    /**
     * Set the operating mode for power. Typically this allows the user to
     * choose between various low-power modes. Entering low-power modes often
     * results in a trade-off between accuracy and power consumption.
     *
     * The new mode takes effect upon calling start().
     *
     * @param power The new power mode.
     * @return      true if the update was successful.
     */
    bool setPowerMode(PowerMode_t power);

    /**
     * HW reset to get location chip into hibernation mode, but in readiness for
     * starting operation. The GPS controller emerges from hibernation when
     * start() is called.
     *
     * The typical initialization sequence is:
     *   reset();
     *   start(); // and thereafter receive location-update callbacks.
     */
    void reset(void);

    /**
     * Start the GPS operation, taking into account the operation mode set
     * previously. Following this call, the user may expect to receive location
     * notifications in interrupt context if a handler has previously been set.
     *
     * @note: calling start repeatedly doesn't hurt.
     */
    void start(void);

    /**
     * Stop active operation of the GPS; and put it to hibernation.
     *
     * @note: You don't need to call reset() afterwards to enter hibernation.
     * @note: Calling stop() repeatedly doesn't hurt.
     */
    void stop(void);

    /**
     * Process location data from chip and update location and satellite
     * information. This API is supposed to be called repeatedly from the
     * application in thread mode to process incoming messages as they are
     * received from the GPS controller. Arriving data is first appended to
     * something like a circular buffer by interrupts, and then parsed as
     * messages in thread mode.
     *
     * The application typically enters a loop calling process() after
     * initializing the GPS controller with start(). process() returns
     * immediately if there is no work to be done, but it must get invoked
     * frequently in order to keep pace with arriving data.
     *
     * Mbed's sleep() may be usefully thrown into the application's process()
     * loop to save power--sleep() has the effect of putting the processor to
     * sleep while waiting for an event (such as an interrupt). As always, some
     * care must be taken in employing sleep(), because there is a small
     * synchronization window where an interrupt may arrive and pend data which
     * doesn't get processed (as illustrated below).
     *
     *  while (true) {
     *      process();
     *        <--  interrupt arrives now and appends new data
     *      sleep(); // but then we go to sleep without processing it.
     *  }
     *
     * There is a way around it: if sleep() boils down to the use of ARM's WFE
     * instruction (as opposed to WFI), then its safe from the above-mentioned
     * synchronization window.
     */
    void process(void);

    /**
     * @return  true if the initialization process has received enough
     *     information to determine the hardware's version/device-info.
     */
    bool haveDeviceInfo(void) const;

    /**
     * Fetch the device information string. This is expected to contain the
     * version number or any other device identifier.
     */
    const char *getDeviceInfo(void) const;

    /**
     * This is a wildcard API for sending controller specific commands. Use of
     * this API will make programs non-portable, but then there may arise a
     * genuine need to access special functionality.
     *
     * @param  command   A controller specific command.
     * @param  arg       Argument to the command; interpreted according to the command.
     * @return           any return from the command.
     */
    uint32_t ioctl(uint32_t command, void *arg);

    /** [ST-GNSS ] - Enable verbose NMEA stream */
    void setVerboseMode(int level);

    /**
     * [ST-GNSS] - Odometer API
     * Enable the Geofencing subsystem.
     * 
     * The Geofencing subsystem is enabled.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t enableGeofence(void);

    /**
     * [ST-GNSS] - Geofencing API
     * Configure the Geofence subsystem.
     *
     * @param  geofences A pointer to an array of geofences to be included within this provider.
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t configGeofences(GPSGeofence *geofences[], unsigned geofenceCount);

    /**
     * [ST-GNSS] - Geofencing API
     * Request a message to know the internal Geofence subsystem status.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t geofenceReq(void);

    /**
     * [ST-GNSS] - Datalogging API
     * Enable the Datalogging subsystem.
     * 
     * The Datalogging subsystem is enabled.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t enableDatalog(void);

    /**
     * [ST-GNSS] - Datalogging API
     * Create and enable a new data log.
     *
     * @param  datalog A pointer to data log.
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t configDatalog(GPSDatalog *datalog);

    /**
     * [ST-GNSS] - Datalogging API
     * Start or restart the current data log.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t startDatalog(void);

    /**
     * [ST-GNSS] - Datalogging API
     * Stop or restart the current data log.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t stopDatalog(void);

    /**
     * [ST-GNSS] - Datalogging API
     * Erase the current data logging.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t eraseDatalog(void);

    /**
     * [ST-GNSS] - Datalogging API
     * Raised from the host to get information about the datalog subsystem.
     *
     * @return GPS_ERROR_NONE on success / GPS_ERROR_LOG_REQ_STATUS on failure.
     */
    gps_provider_error_t logReqStatus(void);

    /**
     * [ST-GNSS] - Datalogging API
     * Trigger a query request to the GNSS receiver.
     *
     * @param  logReqQuery The log query request.
     * @return GPS_ERROR_NONE on success / GPS_ERROR_LOG_REQ_QUERY on failure.
     */
    gps_provider_error_t logReqQuery(LogQueryParams_t &logReqQuery);

    /**
     * [ST-GNSS] - Odometer API
     * Enable the Odometer subsystem.
     * 
     * The Odometer subsystem is enabled.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t enableOdo(void);

    /**
     * [ST-GNSS] - Odometer API
     * Reset the Odometer subsystem.
     * 
     * The Odometer subsystem starts evaluating the ground distance
     * from the current resolved position.
     *
     * @param alarmDistance The distance from the current resolved position
     *                      triggering an alarm
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t startOdo(unsigned alarmDistance);

    /**
     * [ST-GNSS] - Odometer API
     * Stop the Odometer subsystem.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t stopOdo(void);

    /**
     * [ST-GNSS] - Odometer API
     * Reset the Odometer subsystem.
     *
     * @return GPS_ERROR_NONE on success / 
     *         A callback (if set) will be invoked upon a message is received
     *         from the GPS device.
     */
    gps_provider_error_t resetOdo(void);
    
    /**
     * @return  true if we've obtained at least one valid location since last
     *     calling start().
     *
     * @Note: This is cleared after reset().
     */
    bool locationAvailable(void) const;

    /**
     * @return  the last valid location if there is any; else NULL.
     */
    const LocationUpdateParams_t *getLastLocation(void) const;

    /**
     * Type declaration for a callback to be invoked from interrupt context upon
     * receiving new location data.
     *
     * @Note: Please note that the handler gets invoked from interrupt context.
     * Users *should not* do any long running or blocking operations in the
     * handler.
     */
    typedef void (* LocationUpdateCallback_t)(const LocationUpdateParams_t *params);

    /**
     * Setup the locationUpdate callback.
     *
     * @Note: Please note that the handler gets invoked from interrupt context.
     * Users *should not* do any long running or blocking operations in the
     * handler.
     */
    void onLocationUpdate(LocationUpdateCallback_t callback);

    /**
     * In low-power operation, the GPS controller may be expected to hibernate
     * for extended periods and location updates may be infrequent. It should
     * then be possible for an application to demand location data when needed.
     *
     * This calls results in a locationCallback if there is a useful location to
     * report.
     */
    void lpmGetImmediateLocation(void);

    /**
     * [ST-GNSS] - Geofencing API
     */
    bool isGeofencingSupported(void);

    /**
     * [ST-GNSS] - Geofencing API
     *
     * Type declaration for a callback to be invoked upon
     * receiving new geofence cfg message.
     */
    typedef void (* GeofenceCfgMessageCallback_t)(int ret_code);
    /**
     * [ST-GNSS] - Geofencing API
     *
     * Setup the geofenceCfg callback.
     */
    void onGeofenceCfgMessage(GeofenceCfgMessageCallback_t callback);
    /**
     * [ST-GNSS] - Geofencing API
     *
     * Type declaration for a callback to be invoked upon
     * receiving new geofence status message.
     */
    typedef void (* GeofenceStatusMessageCallback_t)(const GeofenceStatusParams_t *params, int ret_code);
    /**
     * [ST-GNSS] - Geofencing API
     *
     * Setup the geofenceStatus callback.
     */
    void onGeofenceStatusMessage(GeofenceStatusMessageCallback_t callback);

    /**
     * [ST-GNSS] - Datalogging API
     */
    bool isDataloggingSupported(void);
    
    /**
     * [ST-GNSS] - Datalogging API
     *
     * Type declaration for a callback to be invoked upon
     * receiving new log status message.
     *
     * Report the internal data log subsystem state.
     */
    typedef void (* LogStatusCallback_t)(const LogStatusParams_t *params);

    /**
     * [ST-GNSS] - Datalogging API
     *
     * Setup the log status callback.
     */
    void onLogStatus(LogStatusCallback_t callback);

    /**
     * [ST-GNSS] - Datalogging API
     *
     * Type declaration for a callback to be invoked upon
     * receiving new log query message compliant to the query raised by the host.
     */
    typedef void (* LogQueryCallback_t)(const LogQueryRespParams_t *params);

    /**
     * [ST-GNSS] - Datalogging API
     *
     * Setup the log query callback.
     */
    void onLogQuery(LogQueryCallback_t callback);

    /**
     * [ST-GNSS] - Odometer API
     */
    bool isOdometerSupported(void);
    
    /**
     * [ST-GNSS] - Odometer API
     *
     * Type declaration for a callback to be invoked upon
     * receiving new odometer subsystem megssage.
     */
    typedef void (* OdoCallback_t)(const OdoParams_t *params);
    
    /**
     * [ST-GNSS] - Datalogging API
     *
     * Setup the odometer callback.
     */
    void onOdo(OdoCallback_t callback);
    
public:
    /**
     * Default constructor.
     */
    GPSProvider() : impl(createGPSProviderInstance()) {
        /* empty */
    }

    virtual ~GPSProvider() {
        stop();
    }

private:
    /**
     * We use 'composition' to combine a driver-implementation object to the
     * GPSProvider interface. The implementation object will come to life
     * through the createGPSProviderInstance(), which must be defined by the
     * driver library. The mechanics of the implementation are to be hidden
     * behind the abstract interface provided by GPSProvider.
     */
    GPSProviderImplBase *const impl;

    /* disallow copy constructor and assignment operators */
private:
    GPSProvider(const GPSProvider&);
    GPSProvider & operator= (const GPSProvider&);
};

#endif /*__GPS_PROVIDER_H__*/