diff --git a/include/hardware/gps.h b/include/hardware/gps.h index 7244738b..3cb006b9 100644 --- a/include/hardware/gps.h +++ b/include/hardware/gps.h @@ -22,6 +22,7 @@ #include #include #include +#include #include @@ -39,6 +40,9 @@ typedef int64_t GpsUtcTime; /** Maximum number of SVs for gps_sv_status_callback(). */ #define GPS_MAX_SVS 32 +/** Maximum number of Measurements in gps_measurement_callback(). */ +#define GPS_MAX_MEASUREMENT 32 + /** Requested operational mode for GPS operation. */ typedef uint32_t GpsPositionMode; // IMPORTANT: Note that the following values must match @@ -212,6 +216,102 @@ typedef uint16_t AGpsStatusValue; #define AGPS_RIL_NETWORK_TTYPE_MOBILE_HIPRI 5 #define AGPS_RIL_NETWORK_TTYPE_WIMAX 6 +/** + * Flags to indicate what fields in GpsClock are valid. + */ +typedef uint16_t GpsClockFlags; +/** A valid 'leap second' is stored in the data structure. */ +#define GPS_CLOCK_HAS_LEAP_SECOND (1<<0) +/** A valid 'time uncertainty' is stored in the data structure. */ +#define GPS_CLOCK_HAS_TIME_UNCERTAINTY (1<<1) +/** A valid 'bias' is stored in the data structure. */ +#define GPS_CLOCK_HAS_BIAS (1<<2) +/** A valid 'bias uncertainty' is stored in the data structure. */ +#define GPS_CLOCK_HAS_BIAS_UNCERTAINTY (1<<3) +/** A valid 'drift' is stored in the data structure. */ +#define GPS_CLOCK_HAS_DRIFT (1<<4) +/** A valid 'drift uncertainty' is stored in the data structure. */ +#define GPS_CLOCK_HAS_DRIFT_UNCERTAINTY (1<<5) + +/** + * Flags to indicate what fields in GpsMeasurement are valid. + */ +typedef uint32_t GpsMeasurementFlags; +/** A valid 'snr' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_SNR (1<<0) +/** A valid 'elevation' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_ELEVATION (1<<1) +/** A valid 'elevation uncertainty' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_ELEVATION_UNCERTAINTY (1<<2) +/** A valid 'azimuth' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_AZIMUTH (1<<3) +/** A valid 'azimuth uncertainty' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_AZIMUTH_UNCERTAINTY (1<<4) +/** A valid 'pseudorange' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_PSEUDORANGE (1<<5) +/** A valid 'pseudorange uncertainty' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_PSEUDORANGE_UNCERTAINTY (1<<6) +/** A valid 'code phase' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_CODE_PHASE (1<<7) +/** A valid 'code phase uncertainty' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_CODE_PHASE_UNCERTAINTY (1<<8) +/** A valid 'carrier frequency' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_CARRIER_FREQUENCY (1<<9) +/** A valid 'carrier cycles' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_CARRIER_CYCLES (1<<10) +/** A valid 'carrier phase' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_CARRIER_PHASE (1<<11) +/** A valid 'carrier phase uncertainty' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_CARRIER_PHASE_UNCERTAINTY (1<<12) +/** A valid 'bit number' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_BIT_NUMBER (1<<13) +/** A valid 'time from last bit' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_TIME_FROM_LAST_BIT (1<<14) +/** A valid 'doppler shift' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_DOPPLER_SHIFT (1<<15) +/** A valid 'doppler shift uncertainty' is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_DOPPLER_SHIFT_UNCERTAINTY (1<<16) +/** A valid 'used in fix' flag is stored in the data structure. */ +#define GPS_MEASUREMENT_HAS_USED_IN_FIX (1<<17) + +/** + * Flags that indicate the available values for the GPS Measurement's loss of lock. + */ +typedef uint8_t GpsLossOfLock; +/** The indicator is not available or it is unknown. */ +#define GPS_LOSS_OF_LOCK_UNKNOWN 0 +/** The measurement does not present any indication of loss of lock. */ +#define GPS_LOSS_OF_LOCK_OK 1 +/** Loss of lock between previous and current observation: cycle slip possible. */ +#define GPS_LOSS_OF_LOCK_CYCLE_SLIP 2 + +/** + * Flags that indicate the available values for the GPS Measurement's multipath indicator. + */ +typedef uint8_t GpsMultipathIndicator; +/** The indicator is not available or unknown. */ +#define GPS_MULTIPATH_INDICATOR_UNKNOWN 0 +/** The measurement has been indicated to use multipath. */ +#define GPS_MULTIPATH_INDICATOR_DETECTED 1 +/** The measurement has been indicated Not to use multipath. */ +#define GPS_MULTIPATH_INDICATOR_NOT_USED 2 + +/** + * Flags to indicate the available GPS Natigation message types. + */ +typedef uint8_t GpsNavigationMessageType; +/** The message type is unknown. */ +#define GPS_NAVIGATION_MESSAGE_TYPE_UNKNOWN 0 +/** L1 C/A message contained in the structure. */ +#define GPS_NAVIGATION_MESSAGE_TYPE_L1CA 1 +/** L2-CNAV message contained in the structure. */ +#define GPS_NAVIGATION_MESSAGE_TYPE_L2CNAV 2 +/** L5-CNAV message contained in the structure. */ +#define GPS_NAVIGATION_MESSAGE_TYPE_L5CNAV 3 +/** CNAV-2 message contained in the structure. */ +#define GPS_NAVIGATION_MESSAGE_TYPE_CNAV2 4 + + /** * Name for the GPS XTRA interface. */ @@ -247,6 +347,16 @@ typedef uint16_t AGpsStatusValue; */ #define GPS_GEOFENCING_INTERFACE "gps_geofencing" +/** + * Name of the GPS Measurements interface. + */ +#define GPS_MEASUREMENT_INTERFACE "gps_measurement" + +/** + * Name of the GPS navigation message interface. + */ + #define GPS_NAVIGATION_MESSAGE_INTERFACE "gps_navigation_message" + /** Represents a location. */ typedef struct { @@ -320,6 +430,7 @@ typedef struct { uint32_t used_in_fix_mask; } GpsSvStatus; + /* 2G and 3G */ /* In 3G lac is discarded */ typedef struct { @@ -353,8 +464,9 @@ typedef void (* gps_location_callback)(GpsLocation* location); */ typedef void (* gps_status_callback)(GpsStatus* status); -/** Callback with SV status information. - * Can only be called from a thread created by create_thread_cb. +/** + * Callback with SV status information. + * Can only be called from a thread created by create_thread_cb. */ typedef void (* gps_sv_status_callback)(GpsSvStatus* sv_info); @@ -406,7 +518,7 @@ typedef struct { size_t size; /** * Opens the interface and provides the callback routines - * to the implemenation of this interface. + * to the implementation of this interface. */ int (*init)( GpsCallbacks* callbacks ); @@ -467,7 +579,7 @@ typedef struct { size_t size; /** * Opens the XTRA interface and provides the callback routines - * to the implemenation of this interface. + * to the implementation of this interface. */ int (*init)( GpsXtraCallbacks* callbacks ); /** Injects XTRA data into the GPS. */ @@ -547,7 +659,7 @@ typedef struct { /** * Opens the AGPS interface and provides the callback routines - * to the implemenation of this interface. + * to the implementation of this interface. */ void (*init)( AGpsCallbacks* callbacks ); /** @@ -631,7 +743,7 @@ typedef struct { u_char data[20]; } Sha1CertificateFingerprint; -/** AGPS Inteface to handle SUPL certificate operations */ +/** AGPS Interface to handle SUPL certificate operations */ typedef struct { /** set to sizeof(SuplCertificateInterface) */ size_t size; @@ -803,7 +915,7 @@ typedef struct { size_t size; /** * Opens the AGPS interface and provides the callback routines - * to the implemenation of this interface. + * to the implementation of this interface. */ void (*init)( AGpsRilCallbacks* callbacks ); @@ -942,7 +1054,7 @@ typedef void (*gps_geofence_transition_callback) (int32_t geofence_id, GpsLocat int32_t transition, GpsUtcTime timestamp); /** - * The callback associated with the availablity of the GPS system for geofencing + * The callback associated with the availability of the GPS system for geofencing * monitoring. If the GPS system determines that it cannot monitor geofences * because of lack of reliability or unavailability of the GPS signals, it will * call this callback with GPS_GEOFENCE_UNAVAILABLE parameter. @@ -1020,7 +1132,7 @@ typedef struct { /** * Opens the geofence interface and provides the callback routines - * to the implemenation of this interface. + * to the implementation of this interface. */ void (*init)( GpsGeofenceCallbacks* callbacks ); @@ -1050,14 +1162,12 @@ typedef struct { * sampling the GPS for power-saving reasons; thus the rate of * sampling may be faster or slower than this. * unknown_timer_ms - The time limit after which the UNCERTAIN transition - * should be triggered. This paramter is defined in milliseconds. + * should be triggered. This parameter is defined in milliseconds. * See above for a detailed explanation. */ - void (*add_geofence_area) (int32_t geofence_id, double latitude, - double longitude, double radius_meters, - int last_transition, int monitor_transitions, - int notification_responsiveness_ms, - int unknown_timer_ms); + void (*add_geofence_area) (int32_t geofence_id, double latitude, double longitude, + double radius_meters, int last_transition, int monitor_transitions, + int notification_responsiveness_ms, int unknown_timer_ms); /** * Pause monitoring a particular geofence. @@ -1086,6 +1196,471 @@ typedef struct { */ void (*remove_geofence_area) (int32_t geofence_id); } GpsGeofencingInterface; + + +/** + * Represents an estimate of the GPS clock time. + */ +typedef struct { + /** set to sizeof(GpsClock) */ + size_t size; + + /** A set of flags indicating the validity of the fields in this data structure. */ + GpsClockFlags flags; + + /** + * Leap second data. + * If the data is available 'flags' must contain GPS_CLOCK_HAS_LEAP_SECOND. + */ + int16_t leap_second; + + /** + * The receiver's GPS time since 0000Z, January 6, 1980 in nanoseconds. + * It is referenced using the uncorrected receiver's clock ('bias_ns' included). + * The current precision allows a range that spans approximately to the end of the year 2272. + * + * Sub-nanosecond accuracy can be provided for each individual measurement using the field + * GpsMeasurement::time_offset_ns. + * + * The value contains the 'time uncertainty' in it. + * This is a Mandatory field. + */ + int64_t time_ns; + + /** + * 1-Sigma uncertainty associated with the clock's time in nanoseconds. + * The uncertainty is represented as an absolute (single sided) value. + * + * If the data is available 'flags' must contain GPS_CLOCK_HAS_TIME_UNCERTAINTY. + */ + double time_uncertainty_ns; + + /** + * The clock's bias in nanoseconds. + * The sign of the value is defined by the following equation: + * true time = time - bias. + * + * The value contains the 'bias uncertainty' in it. + * If the data is available 'flags' must contain GPS_CLOCK_HAS_BIAS. + */ + double bias_ns; + + /** + * 1-Sigma uncertainty associated with the clock's bias in nanoseconds. + * The uncertainty is represented as an absolute (single sided) value. + * + * If the data is available 'flags' must contain GPS_CLOCK_HAS_BIAS_UNCERTAINTY. + */ + double bias_uncertainty_ns; + + /** + * The clock's drift in nanoseconds (per second). + * A positive value means that the frequency is higher than the nominal frequency. + * + * The value contains the 'drift uncertainty' in it. + * If the data is available 'flags' must contain GPS_CLOCK_HAS_DRIFT. + */ + double drift_nsps; + + /** + * 1-Sigma uncertainty associated with the clock's drift in nanoseconds (per second). + * The uncertainty is represented as an absolute (single sided) value. + * + * If the data is available 'flags' must contain GPS_CLOCK_HAS_DRIFT_UNCERTAINTY. + */ + double drift_uncertainty_nsps; +} GpsClock; + +/** + * Represents a GPS Measurement, it contains raw and computed information. + */ +typedef struct { + /** set to sizeof(GpsMeasurement) */ + size_t size; + + /** A set of flags indicating the validity of the fields in this data structure. */ + GpsMeasurementFlags flags; + + /** + * Pseudo-random number in the range of [1, 32] + * This is a Mandatory value. + */ + int8_t prn; + + /** + * Local hardware time offset at which the measurement was taken in nanoseconds. + * The reference receiver's time is specified by GpsData::clock. + * The sign of time_offset_ns is given by the following equation: + * measurement time = GpsClock::time_ns + time_offset_ns + * + * It provides an individual time-stamp for the measurement, and allows sub-nanosecond accuracy. + * This is a Mandatory value. + */ + int64_t time_offset_ns; + + /** + * Received GPS Time-of-Week in nanoseconds. + * The value is relative to the beginning of the current GPS week. + * + * This is a Mandatory value. + */ + int64_t received_gps_tow_ns; + + /** + * Carrier-to-noise density in dB-Hz, in the range [0, 63]. + * It contains the measured C/N0 value for the signal at the antenna input. + * + * This is a Mandatory value. + */ + double c_n0_dbhz; + + /** + * Pseudorange rate at the timestamp in m/s. + * The value also includes the effects of the receiver clock frequency and satellite clock + * frequency errors. + * + * The value includes the 'pseudorange rate uncertainty' in it. + * A positive value indicates that the pseudorange is getting larger. + * + * This is a Mandatory value. + */ + double pseudorange_rate_mpersec; + + /** + * 1-Sigma uncertainty of the pseudurange rate in m/s. + * The uncertainty is represented as an absolute (single sided) value. + * + * This is a Mandatory value. + */ + double pseudorange_rate_uncertainty_mpersec; + + /** + * Accumulated delta range since the last channel reset in meters. + * + * This is a Mandatory value. + */ + double accumulated_delta_range_m; + + /** + * 1-Sigma uncertainty of the accumulated delta range in meters. + * + * This is a Mandatory value. + */ + double accumulated_delta_range_uncertainty_m; + + /** + * Best derived Pseudorange by the chip-set, in meters. + * The value contains the 'pseudorange uncertainty' in it. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_PSEUDORANGE. + */ + double pseudorange_m; + + /** + * 1-Sigma uncertainty of the pseudorange in meters. + * The value contains the 'pseudorange' and 'clock' uncertainty in it. + * The uncertainty is represented as an absolute (single sided) value. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_PSEUDORANGE_UNCERTAINTY. + */ + double pseudorange_uncertainty_m; + + /** + * A fraction of the current C/A code cycle, in the range [0.0, 1023.0] + * This value contains the time (in Chip units) since the last C/A code cycle (GPS Msec epoch). + * + * The reference frequency is given by the field 'carrier_frequency_hz'. + * The value contains the 'code-phase uncertainty' in it. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_CODE_PHASE. + */ + double code_phase_chips; + + /** + * 1-Sigma uncertainty of the code-phase, in a fraction of chips. + * The uncertainty is represented as an absolute (single sided) value. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_CODE_PHASE_UNCERTAINTY. + */ + double code_phase_uncertainty_chips; + + /** + * Carrier frequency at which codes and messages are modulated, it can be L1 or L2. + * If the field is not set, the carrier frequency is assumed to be L1. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_CARRIER_FREQUENCY. + */ + float carrier_frequency_hz; + + /** + * The number of full carrier cycles between the satellite and the receiver. + * The reference frequency is given by the field 'carrier_frequency_hz'. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_CARRIER_CYCLES. + */ + int64_t carrier_cycles; + + /** + * The RF phase detected by the receiver, in the range [0.0, 1.0]. + * This is usually the fractional part of the complete carrier phase measurement. + * + * The reference frequency is given by the field 'carrier_frequency_hz'. + * The value contains the 'carrier-phase uncertainty' in it. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_CARRIER_PHASE. + */ + double carrier_phase; + + /** + * 1-Sigma uncertainty of the carrier-phase. + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_CARRIER_PHASE_UNCERTAINTY. + */ + double carrier_phase_uncertainty; + + /** + * An enumeration that indicates the 'loss of lock' state of the event. + */ + GpsLossOfLock loss_of_lock; + + /** + * The number of GPS bits transmitted since Sat-Sun midnight (GPS week). + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_BIT_NUMBER. + */ + int16_t bit_number; + + /** + * The elapsed time since the last received bit in nanoseconds, in the range [0, 20,000,000] + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_TIME_FROM_LAST_BIT. + */ + int64_t time_from_last_bit_ns; + + /** + * Doppler shift in Hz. + * A positive value indicates that the SV is moving toward the receiver. + * + * The reference frequency is given by the field 'carrier_frequency_hz'. + * The value contains the 'doppler shift uncertainty' in it. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_DOPPLER_SHIFT. + */ + double doppler_shift_hz; + + /** + * 1-Sigma uncertainty of the doppler shift in Hz. + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_DOPPLER_SHIFT_UNCERTAINTY. + */ + double doppler_shift_uncertainty_hz; + + /** + * An enumeration that indicates the 'multipath' state of the event. + */ + GpsMultipathIndicator multipath_indicator; + + /** + * Signal-to-noise ratio in dB. + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_SNR. + */ + double snr_db; + + /** + * Elevation in degrees, the valid range is [-90, 90]. + * The value contains the 'elevation uncertainty' in it. + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_ELEVATION. + */ + double elevation_deg; + + /** + * 1-Sigma uncertainty of the elevation in degrees, the valid range is [0, 90]. + * The uncertainty is represented as the absolute (single sided) value. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_ELEVATION_UNCERTAINTY. + */ + double elevation_uncertainty_deg; + + /** + * Azimuth in degrees, in the range [0, 360). + * The value contains the 'azimuth uncertainty' in it. + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_AZIMUTH. + * */ + double azimuth_deg; + + /** + * 1-Sigma uncertainty of the azimuth in degrees, the valid range is [0, 180]. + * The uncertainty is represented as an absolute (single sided) value. + * + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_AZIMUTH_UNCERTAINTY. + */ + double azimuth_uncertainty_deg; + + /** + * Whether the GPS represented by the measurement was used for computing the most recent fix. + * If the data is available, 'flags' must contain GPS_MEASUREMENT_HAS_USED_IN_FIX. + */ + bool used_in_fix; +} GpsMeasurement; + +/** Represents a reading of GPS measurements. */ +typedef struct { + /** set to sizeof(GpsData) */ + size_t size; + + /** Number of measurements. */ + size_t measurement_count; + + /** The array of measurements. */ + GpsMeasurement measurements[GPS_MAX_MEASUREMENT]; + + /** The GPS clock time reading. */ + GpsClock clock; +} GpsData; + +/** + * The callback for to report measurements from the HAL. + * + * Parameters: + * data - A data structure containing the measurements. + */ +typedef void (*gps_measurement_callback) (GpsData* data); + +typedef struct { + /** set to sizeof(GpsMeasurementCallbacks) */ + size_t size; + gps_measurement_callback measurement_callback; +} GpsMeasurementCallbacks; + +#define GPS_MEASUREMENT_OPERATION_SUCCESS 0 +#define GPS_MEASUREMENT_ERROR_ALREADY_INIT -100 +#define GPS_MEASUREMENT_ERROR_GENERIC -101 + +/** + * Extended interface for GPS Measurements support. + */ +typedef struct { + /** Set to sizeof(GpsMeasurementInterface) */ + size_t size; + + /** + * Initializes the interface and registers the callback routines with the HAL. + * After a successful call to 'init' the HAL must begin to provide updates at its own phase. + * + * Status: + * GPS_MEASUREMENT_OPERATION_SUCCESS + * GPS_MEASUREMENT_ERROR_ALREADY_INIT - if a callback has already been registered without a + * corresponding call to 'close' + * GPS_MEASUREMENT_ERROR_GENERIC - if any other error occurred, it is expected that the HAL + * will not generate any updates upon returning this error code. + */ + int (*init) (GpsMeasurementCallbacks* callbacks); + + /** + * Stops updates from the HAL, and unregisters the callback routines. + * After a call to stop, the previously registered callbacks must be considered invalid by the + * HAL. + * If stop is invoked without a previous 'init', this function should perform no work. + */ + void (*close) (); + +} GpsMeasurementInterface; + + +/** Represents a GPS navigation message (or a fragment of it). */ +typedef struct { + /** set to sizeof(GpsNavigationMessage) */ + size_t size; + + /** + * Pseudo-random number in the range of [1, 32] + * This is a Mandatory value. + */ + int8_t prn; + + /** + * The type of message contained in the structure. + * This is a Mandatory value. + */ + GpsNavigationMessageType type; + + /** + * Message identifier. + * It provides an index so the complete Navigation Message can be assembled. + * i.e. for L1 C/A the message id corresponds to the frame id of the navigation message. + */ + int16_t message_id; + + /** + * Sub-message identifier. + * If required by the message 'type', this value contains a sub-index within the current + * message (or frame) that is being transmitted. + * i.e. for L1 C/A the submessage id corresponds to the sub-frame id of the navigation message. + */ + int16_t submessage_id; + + /** + * The length of the data (in bytes) contained in the current message. + * If this value is different from zero, 'data' must point to an array of the same size. + * i.e. for L1 C/A the size of the sub-frame will be 40 bytes (10 words). + * + * This is a Mandatory value. + */ + size_t data_length; + + /** + * The data of the reported GPS message. + * The bytes (or words) specified using big endian format (MSB first). + */ + uint8_t* data; + +} GpsNavigationMessage; + +/** + * The callback to report an available fragment of a GPS navigation messages from the HAL. + * + * Parameters: + * message - The GPS navigation submessage/subframe representation. + */ +typedef void (*gps_navigation_message_callback) (GpsNavigationMessage* message); + +typedef struct { + /** set to sizeof(GpsNavigationMessageCallbacks) */ + size_t size; + gps_navigation_message_callback navigation_message_callback; +} GpsNavigationMessageCallbacks; + +#define GPS_NAVIGATION_MESSAGE_OPERATION_SUCCESS 0 +#define GPS_NAVIGATION_MESSAGE_ERROR_ALREADY_INIT -100 +#define GPS_NAVIGATION_MESSAGE_ERROR_GENERIC -101 + +/** + * Extended interface for GPS navigation message reporting support. + */ +typedef struct { + /** Set to sizeof(GpsNavigationMessageInterface) */ + size_t size; + + /** + * Initializes the interface and registers the callback routines with the HAL. + * After a successful call to 'init' the HAL must begin to provide updates as they become + * available. + * + * Status: + * GPS_NAVIGATION_MESSAGE_OPERATION_SUCCESS + * GPS_NAVIGATION_MESSAGE_ERROR_ALREADY_INIT - if a callback has already been registered + * without a corresponding call to 'close'. + * GPS_NAVIGATION_MESSAGE_ERROR_GENERIC - if any other error occurred, it is expected that + * the HAL will not generate any updates upon returning this error code. + */ + int (*init) (GpsNavigationMessageCallbacks* callbacks); + + /** + * Stops updates from the HAL, and unregisters the callback routines. + * After a call to stop, the previously registered callbacks must be considered invalid by the + * HAL. + * If stop is invoked without a previous 'init', this function should perform no work. + */ + void (*close) (); + +} GpsNavigationMessageInterface; + __END_DECLS #endif /* ANDROID_INCLUDE_HARDWARE_GPS_H */