sensors.h revision 51704bed795b5b0e5e3c7b792dcdc2bf2d96a9e9
1/* 2 * Copyright (C) 2008 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_SENSORS_INTERFACE_H 18#define ANDROID_SENSORS_INTERFACE_H 19 20#include <stdint.h> 21#include <sys/cdefs.h> 22#include <sys/types.h> 23 24#include <hardware/hardware.h> 25 26__BEGIN_DECLS 27 28/** 29 * The id of this module 30 */ 31#define SENSORS_HARDWARE_MODULE_ID "sensors" 32 33/** 34 * Name of the sensors device to open 35 */ 36#define SENSORS_HARDWARE_CONTROL "control" 37#define SENSORS_HARDWARE_DATA "data" 38 39/** 40 * Handles must be higher than SENSORS_HANDLE_BASE 41 */ 42#define SENSORS_HANDLE_BASE 0 43#define SENSORS_HANDLE_BITS 8 44#define SENSORS_HANDLE_COUNT (1<<SENSORS_HANDLE_BITS) 45 46 47/** 48 * Sensor types 49 */ 50#define SENSOR_TYPE_ACCELEROMETER 1 51#define SENSOR_TYPE_MAGNETIC_FIELD 2 52#define SENSOR_TYPE_ORIENTATION 3 53#define SENSOR_TYPE_GYROSCOPE 4 54#define SENSOR_TYPE_LIGHT 5 55#define SENSOR_TYPE_PRESSURE 6 56#define SENSOR_TYPE_TEMPERATURE 7 57#define SENSOR_TYPE_PROXIMITY 8 58 59/** 60 * Values returned by the accelerometer in various locations in the universe. 61 * all values are in SI units (m/s^2) 62 */ 63 64#define GRAVITY_SUN (275.0f) 65#define GRAVITY_MERCURY (3.70f) 66#define GRAVITY_VENUS (8.87f) 67#define GRAVITY_EARTH (9.80665f) 68#define GRAVITY_MOON (1.6f) 69#define GRAVITY_MARS (3.71f) 70#define GRAVITY_JUPITER (23.12f) 71#define GRAVITY_SATURN (8.96f) 72#define GRAVITY_URANUS (8.69f) 73#define GRAVITY_NEPTUNE (11.0f) 74#define GRAVITY_PLUTO (0.6f) 75#define GRAVITY_DEATH_STAR_I (0.000000353036145f) 76#define GRAVITY_THE_ISLAND (4.815162342f) 77 78/** Maximum magnetic field on Earth's surface */ 79#define MAGNETIC_FIELD_EARTH_MAX (60.0f) 80 81/** Minimum magnetic field on Earth's surface */ 82#define MAGNETIC_FIELD_EARTH_MIN (30.0f) 83 84 85/** 86 * status of each sensor 87 */ 88 89#define SENSOR_STATUS_UNRELIABLE 0 90#define SENSOR_STATUS_ACCURACY_LOW 1 91#define SENSOR_STATUS_ACCURACY_MEDIUM 2 92#define SENSOR_STATUS_ACCURACY_HIGH 3 93 94/** 95 * Definition of the axis 96 * ---------------------- 97 * 98 * This API is relative to the screen of the device in its default orientation, 99 * that is, if the device can be used in portrait or landscape, this API 100 * is only relative to the NATURAL orientation of the screen. In other words, 101 * the axis are not swapped when the device's screen orientation changes. 102 * Higher level services /may/ perform this transformation. 103 * 104 * x<0 x>0 105 * ^ 106 * | 107 * +-----------+--> y>0 108 * | | 109 * | | 110 * | | 111 * | | / z<0 112 * | | / 113 * | | / 114 * O-----------+/ 115 * |[] [ ] []/ 116 * +----------/+ y<0 117 * / 118 * / 119 * |/ z>0 (toward the sky) 120 * 121 * O: Origin (x=0,y=0,z=0) 122 * 123 * 124 * Orientation 125 * ----------- 126 * 127 * All values are angles in degrees. 128 * 129 * azimuth: angle between the magnetic north direction and the Y axis, around 130 * the Z axis (0<=azimuth<360). 131 * 0=North, 90=East, 180=South, 270=West 132 * 133 * pitch: Rotation around X axis (-180<=pitch<=180), with positive values when 134 * the z-axis moves toward the y-axis. 135 * 136 * roll: Rotation around Y axis (-90<=roll<=90), with positive values when 137 * the z-axis moves AWAY from the x-axis. 138 * 139 * Note: This definition is different from yaw, pitch and roll used in aviation 140 * where the X axis is along the long side of the plane (tail to nose). 141 * 142 * 143 * Acceleration 144 * ------------ 145 * 146 * All values are in SI units (m/s^2) and measure the acceleration of the 147 * device minus the force of gravity. 148 * 149 * x: Acceleration minus Gx on the x-axis 150 * y: Acceleration minus Gy on the y-axis 151 * z: Acceleration minus Gz on the z-axis 152 * 153 * Examples: 154 * When the device lies flat on a table and is pushed on its left side 155 * toward the right, the x acceleration value is positive. 156 * 157 * When the device lies flat on a table, the acceleration value is +9.81, 158 * which correspond to the acceleration of the device (0 m/s^2) minus the 159 * force of gravity (-9.81 m/s^2). 160 * 161 * When the device lies flat on a table and is pushed toward the sky, the 162 * acceleration value is greater than +9.81, which correspond to the 163 * acceleration of the device (+A m/s^2) minus the force of 164 * gravity (-9.81 m/s^2). 165 * 166 * 167 * Magnetic Field 168 * -------------- 169 * 170 * All values are in micro-Tesla (uT) and measure the ambient magnetic 171 * field in the X, Y and Z axis. 172 * 173 */ 174typedef struct { 175 union { 176 float v[3]; 177 struct { 178 float x; 179 float y; 180 float z; 181 }; 182 struct { 183 float azimuth; 184 float pitch; 185 float roll; 186 }; 187 }; 188 int8_t status; 189 uint8_t reserved[3]; 190} sensors_vec_t; 191 192/** 193 * Union of the various types of sensor data 194 * that can be returned. 195 */ 196typedef struct { 197 /* sensor identifier */ 198 int sensor; 199 200 union { 201 /* x,y,z values of the given sensor */ 202 sensors_vec_t vector; 203 204 /* orientation values are in degrees */ 205 sensors_vec_t orientation; 206 207 /* acceleration values are in meter per second per second (m/s^2) */ 208 sensors_vec_t acceleration; 209 210 /* magnetic vector values are in micro-Tesla (uT) */ 211 sensors_vec_t magnetic; 212 213 /* temperature is in degrees centigrade (Celsius) */ 214 float temperature; 215 }; 216 217 /* time is in nanosecond */ 218 int64_t time; 219 220 uint32_t reserved; 221} sensors_data_t; 222 223 224struct sensor_t; 225 226/** 227 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 228 * and the fields of this data structure must begin with hw_module_t 229 * followed by module specific information. 230 */ 231struct sensors_module_t { 232 struct hw_module_t common; 233 234 /** 235 * @return bit map of available sensors defined by 236 * the constants SENSORS_XXXX. 237 */ 238 int (*get_sensors_list)(struct sensors_module_t* module, 239 struct sensor_t const**); 240}; 241 242struct sensor_t { 243 const char* name; 244 const char* vendor; 245 int version; 246 int handle; 247 int type; 248 float maxRange; 249 float resolution; 250 float power; 251 void* reserved[9]; 252}; 253 254 255/** 256 * Every device data structure must begin with hw_device_t 257 * followed by module specific public methods and attributes. 258 */ 259struct sensors_control_device_t { 260 struct hw_device_t common; 261 262 /** 263 * Returns the fd which will be the parameter to 264 * sensors_data_device_t::open_data(). 265 * The caller takes ownership of this fd. This is intended to be 266 * passed cross processes. 267 * 268 * @return a fd if successful, < 0 on error 269 */ 270 int (*open_data_source)(struct sensors_control_device_t *dev); 271 272 /** Activate/deactivate one or more of the sensors. 273 * 274 * @param sensors is the handle of the sensors to change. 275 * @param enabled set to 1 to enable, or 0 to disable the sensor. 276 * 277 * @return 0 on success, negative errno code otherwise 278 */ 279 int (*activate)(struct sensors_control_device_t *dev, 280 int handle, int enabled); 281 282 /** 283 * Set the delay between sensor events in ms 284 * 285 * @return 0 if successful, < 0 on error 286 */ 287 int (*set_delay)(struct sensors_control_device_t *dev, int32_t ms); 288 289 /** 290 * Causes sensors_data_device_t.poll() to return -EWOULDBLOCK immediately. 291 */ 292 int (*wake)(struct sensors_control_device_t *dev); 293}; 294 295struct sensors_data_device_t { 296 struct hw_device_t common; 297 298 /** 299 * Prepare to read sensor data. 300 * 301 * This routine does NOT take ownership of the fd 302 * and must not close it. Typically this routine would 303 * use a duplicate of the fd parameter. 304 * 305 * @param fd from sensors_control_open. 306 * 307 * @return 0 if successful, < 0 on error 308 */ 309 int (*data_open)(struct sensors_data_device_t *dev, int fd); 310 311 /** 312 * Caller has completed using the sensor data. 313 * The caller will not be blocked in sensors_data_poll 314 * when this routine is called. 315 * 316 * @return 0 if successful, < 0 on error 317 */ 318 int (*data_close)(struct sensors_data_device_t *dev); 319 320 /** 321 * Return sensor data for one of the enabled sensors. 322 * 323 * @return sensor handle for the returned data, 0x7FFFFFFF when 324 * sensors_control_device_t.wake() is called and -errno on error 325 * 326 */ 327 int (*poll)(struct sensors_data_device_t *dev, 328 sensors_data_t* data); 329}; 330 331 332/** convenience API for opening and closing a device */ 333 334static inline int sensors_control_open(const struct hw_module_t* module, 335 struct sensors_control_device_t** device) { 336 return module->methods->open(module, 337 SENSORS_HARDWARE_CONTROL, (struct hw_device_t**)device); 338} 339 340static inline int sensors_control_close(struct sensors_control_device_t* device) { 341 return device->common.close(&device->common); 342} 343 344static inline int sensors_data_open(const struct hw_module_t* module, 345 struct sensors_data_device_t** device) { 346 return module->methods->open(module, 347 SENSORS_HARDWARE_DATA, (struct hw_device_t**)device); 348} 349 350static inline int sensors_data_close(struct sensors_data_device_t* device) { 351 return device->common.close(&device->common); 352} 353 354 355__END_DECLS 356 357#endif // ANDROID_SENSORS_INTERFACE_H 358