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| -rw-r--r-- | include/hardware/gps.h | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/include/hardware/gps.h b/include/hardware/gps.h index 4f91ffb..ba6eb5c 100644 --- a/include/hardware/gps.h +++ b/include/hardware/gps.h @@ -233,6 +233,11 @@ typedef uint16_t AGpsStatusValue; */ #define AGPS_USE_PSC +/* + * Name for the GPS_Geofencing interface. + */ +#define GPS_GEOFENCING_INTERFACE "gps_geofencing" + /** Represents a location. */ typedef struct { /** set to sizeof(GpsLocation) */ @@ -687,7 +692,257 @@ typedef struct { */ void (*update_network_availability) (int avaiable, const char* apn); } AGpsRilInterface; +/** + * GPS Geofence. + * There are 3 states associated with a Geofence: Inside, Outside, Unknown. + * There are 3 transitions: ENTERED, EXITED, UNCERTAIN. + * + * An example state diagram with confidence level: 95% and Unknown time limit + * set as 30 secs is shown below. (confidence level and Unknown time limit are + * explained latter) + * ____________________________ + * | Unknown (30 secs) | + * """""""""""""""""""""""""""" + * ^ | | ^ + * UNCERTAIN| |ENTERED EXITED| |UNCERTAIN + * | v v | + * ________ EXITED _________ + * | Inside | -----------> | Outside | + * | | <----------- | | + * """""""" ENTERED """"""""" + * + * Inside state: We are 95% confident that the user is inside the geofence. + * Outside state: We are 95% confident that the user is outside the geofence + * Unknown state: Rest of the time. + * + * The Unknown state is better explained with an example: + * + * __________ + * | c| + * | ___ | _______ + * | |a| | | b | + * | """ | """"""" + * | | + * """""""""" + * In the diagram above, "a" and "b" are 2 geofences and "c" is the accuracy + * circle reported by the GPS subsystem. Now with regard to "b", the system is + * confident that the user is outside. But with regard to "a" is not confident + * whether it is inside or outside the geofence. If the accuracy remains the + * same for a sufficient period of time, the UNCERTAIN transition would be + * triggered with the state set to Unknown. If the accuracy improves later, an + * appropriate transition should be triggered. This "sufficient period of time" + * is defined by the parameter in the add_geofence_area API. + * In other words, Unknown state can be interpreted as a state in which the + * GPS subsystem isn't confident enough that the user is either inside or + * outside the Geofence. It moves to Unknown state only after the expiry of the + * timeout. + * + * The geofence callback needs to be triggered for the ENTERED and EXITED + * transitions, when the GPS system is confident that the user has entered + * (Inside state) or exited (Outside state) the Geofence. An implementation + * which uses a value of 95% as the confidence is recommended. The callback + * should be triggered only for the transitions requested by the + * add_geofence_area call. + * + * Even though the diagram and explanation talks about states and transitions, + * the callee is only interested in the transistions. The states are mentioned + * here for illustrative purposes. + * + * Startup Scenario: When the device boots up, if an application adds geofences, + * and then we get an accurate GPS location fix, it needs to trigger the + * appropriate (ENTERED or EXITED) transition for every Geofence it knows about. + * By default, all the Geofences will be in the Unknown state. + * + * When the GPS system is unavailable, gps_geofence_status_callback should be + * called to inform the upper layers of the same. Similarly, when it becomes + * available the callback should be called. This is a global state while the + * UNKNOWN transition described above is per geofence. + * + * An important aspect to note is that users of this API (framework), will use + * other subsystems like wifi, sensors, cell to handle Unknown case and + * hopefully provide a definitive state transition to the third party + * application. GPS Geofence will just be a signal indicating what the GPS + * subsystem knows about the Geofence. + * + */ +#define GPS_GEOFENCE_ENTERED (1<<0L) +#define GPS_GEOFENCE_EXITED (1<<1L) +#define GPS_GEOFENCE_UNCERTAIN (1<<2L) + +#define GPS_GEOFENCE_UNAVAILABLE (1<<0L) +#define GPS_GEOFENCE_AVAILABLE (1<<1L) + +#define GPS_GEOFENCE_OPERATION_SUCCESS 0 +#define GPS_GEOFENCE_ERROR_TOO_MANY_GEOFENCES -100 +#define GPS_GEOFENCE_ERROR_ID_EXISTS -101 +#define GPS_GEOFENCE_ERROR_ID_UNKNOWN -102 +#define GPS_GEOFENCE_ERROR_INVALID_TRANSITION -103 +#define GPS_GEOFENCE_ERROR_GENERIC -149 +/** +* The callback associated with the geofence. +* Parameters: +* geofence_id - The id associated with the add_geofence_area. +* location - The current GPS location. +* transition - Can be one of GPS_GEOFENCE_ENTERED, GPS_GEOFENCE_EXITED, +* GPS_GEOFENCE_UNCERTAIN. +* timestamp - Timestamp when the transition was detected. +* +* The callback should only be called when the caller is interested in that +* particular transition. For instance, if the caller is interested only in +* ENTERED transition, then the callback should NOT be called with the EXITED +* transition. +* +* IMPORTANT: If a transition is triggered resulting in this callback, the GPS +* subsystem will wake up the application processor, if its in suspend state. +*/ +typedef void (*gps_geofence_transition_callback) (int32_t geofence_id, GpsLocation* location, +int32_t transition, GpsUtcTime timestamp); + +/** + * The callback associated with the availablity 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. + * + * Parameters: + * status - GPS_GEOFENCE_UNAVAILABLE or GPS_GEOFENCE_AVAILABLE. + * last_location - Last known location. + */ +typedef void (*gps_geofence_status_callback) (int32_t status, GpsLocation* last_location); +/** + * The callback associated with the add_geofence call. + * + * Parameter: + * geofence_id - Id of the geofence. + * status - GPS_GEOFENCE_OPERATION_SUCCESS + * GPS_GEOFENCE_ERROR_TOO_MANY_GEOFENCES - geofence limit has been reached. + * GPS_GEOFENCE_ERROR_ID_EXISTS - geofence with id already exists + * GPS_GEOFENCE_ERROR_INVALID_TRANSITION - the monitorTransition contains an + * invalid transition + * GPS_GEOFENCE_ERROR_GENERIC - for other errors. + */ +typedef void (*gps_geofence_add_callback) (int32_t geofence_id, int32_t status); + +/** + * The callback associated with the remove_geofence call. + * + * Parameter: + * geofence_id - Id of the geofence. + * status - GPS_GEOFENCE_OPERATION_SUCCESS + * GPS_GEOFENCE_ERROR_ID_UNKNOWN - for invalid id + * GPS_GEOFENCE_ERROR_GENERIC for others. + */ +typedef void (*gps_geofence_remove_callback) (int32_t geofence_id, int32_t status); + + +/** + * The callback associated with the pause_geofence call. + * + * Parameter: + * geofence_id - Id of the geofence. + * status - GPS_GEOFENCE_OPERATION_SUCCESS + * GPS_GEOFENCE_ERROR_ID_UNKNOWN - for invalid id + * GPS_GEOFENCE_ERROR_INVALID_TRANSITION - + * when monitor_transitions is invalid + * GPS_GEOFENCE_ERROR_GENERIC for others. + */ +typedef void (*gps_geofence_pause_callback) (int32_t geofence_id, int32_t status); + +/** + * The callback associated with the resume_geofence call. + * + * Parameter: + * geofence_id - Id of the geofence. + * status - GPS_GEOFENCE_OPERATION_SUCCESS + * GPS_GEOFENCE_ERROR_ID_UNKNOWN - for invalid id + * GPS_GEOFENCE_ERROR_GENERIC for others. + */ +typedef void (*gps_geofence_resume_callback) (int32_t geofence_id, int32_t status); + +typedef struct { + gps_geofence_transition_callback geofence_transition_callback; + gps_geofence_status_callback geofence_status_callback; + gps_geofence_add_callback geofence_add_callback; + gps_geofence_remove_callback geofence_remove_callback; + gps_geofence_pause_callback geofence_pause_callback; + gps_geofence_resume_callback geofence_resume_callback; + gps_create_thread create_thread_cb; +} GpsGeofenceCallbacks; + +/** Extended interface for GPS_Geofencing support */ +typedef struct { + /** set to sizeof(GpsGeofencingInterface) */ + size_t size; + + /** + * Opens the geofence interface and provides the callback routines + * to the implemenation of this interface. + */ + void (*init)( GpsGeofenceCallbacks* callbacks ); + + /** + * Add a geofence area. This api currently supports circular geofences. + * Parameters: + * geofence_id - The id for the geofence. If a geofence with this id + * already exists, an error value (GPS_GEOFENCE_ERROR_ID_EXISTS) + * should be returned. + * latitude, longtitude, radius_meters - The lat, long and radius + * (in meters) for the geofence + * last_transition - The current state of the geofence. For example, if + * the system already knows that the user is inside the geofence, + * this will be set to GPS_GEOFENCE_ENTERED. In most cases, it + * will be GPS_GEOFENCE_UNCERTAIN. + * monitor_transition - Which transitions to monitor. Bitwise OR of + * GPS_GEOFENCE_ENTERED, GPS_GEOFENCE_EXITED and + * GPS_GEOFENCE_UNCERTAIN. + * notification_responsiveness_ms - Defines the best-effort description + * of how soon should the callback be called when the transition + * associated with the Geofence is triggered. For instance, if set + * to 1000 millseconds with GPS_GEOFENCE_ENTERED, the callback + * should be called 1000 milliseconds within entering the geofence. + * This parameter is defined in milliseconds. + * NOTE: This is not to be confused with the rate that the GPS is + * polled at. It is acceptable to dynamically vary the rate of + * 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. + * 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); + + /** + * Pause monitoring a particular geofence. + * Parameters: + * geofence_id - The id for the geofence. + */ + void (*pause_geofence) (int32_t geofence_id); + + /** + * Resume monitoring a particular geofence. + * Parameters: + * geofence_id - The id for the geofence. + * monitor_transitions - Which transitions to monitor. Bitwise OR of + * GPS_GEOFENCE_ENTERED, GPS_GEOFENCE_EXITED and + * GPS_GEOFENCE_UNCERTAIN. + * This supersedes the value associated provided in the + * add_geofence_area call. + */ + void (*resume_geofence) (int32_t geofence_id, int monitor_transitions); + + /** + * Remove a geofence area. After the function returns, no notifications + * should be sent. + * Parameter: + * geofence_id - The id for the geofence. + */ + void (*remove_geofence_area) (int32_t geofence_id); +} GpsGeofencingInterface; __END_DECLS #endif /* ANDROID_INCLUDE_HARDWARE_GPS_H */ |