sensors.h revision f5a22bcfa64f4f33b5877cd44761363af952b768
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#include <cutils/native_handle.h> 26 27__BEGIN_DECLS 28 29/** 30 * The id of this module 31 */ 32#define SENSORS_HARDWARE_MODULE_ID "sensors" 33 34/** 35 * Name of the sensors device to open 36 */ 37#define SENSORS_HARDWARE_CONTROL "control" 38#define SENSORS_HARDWARE_DATA "data" 39 40/** 41 * Handles must be higher than SENSORS_HANDLE_BASE and must be unique. 42 * A Handle identifies a given sensors. The handle is used to activate 43 * and/or deactivate sensors. 44 * In this version of the API there can only be 256 handles. 45 */ 46#define SENSORS_HANDLE_BASE 0 47#define SENSORS_HANDLE_BITS 8 48#define SENSORS_HANDLE_COUNT (1<<SENSORS_HANDLE_BITS) 49 50 51/** 52 * Sensor types 53 */ 54#define SENSOR_TYPE_ACCELEROMETER 1 55#define SENSOR_TYPE_MAGNETIC_FIELD 2 56#define SENSOR_TYPE_ORIENTATION 3 57#define SENSOR_TYPE_GYROSCOPE 4 58#define SENSOR_TYPE_LIGHT 5 59#define SENSOR_TYPE_PRESSURE 6 60#define SENSOR_TYPE_TEMPERATURE 7 61#define SENSOR_TYPE_PROXIMITY 8 62 63/** 64 * Values returned by the accelerometer in various locations in the universe. 65 * all values are in SI units (m/s^2) 66 */ 67 68#define GRAVITY_SUN (275.0f) 69#define GRAVITY_MERCURY (3.70f) 70#define GRAVITY_VENUS (8.87f) 71#define GRAVITY_EARTH (9.80665f) 72#define GRAVITY_MOON (1.6f) 73#define GRAVITY_MARS (3.71f) 74#define GRAVITY_JUPITER (23.12f) 75#define GRAVITY_SATURN (8.96f) 76#define GRAVITY_URANUS (8.69f) 77#define GRAVITY_NEPTUNE (11.0f) 78#define GRAVITY_PLUTO (0.6f) 79#define GRAVITY_DEATH_STAR_I (0.000000353036145f) 80#define GRAVITY_THE_ISLAND (4.815162342f) 81 82/** Maximum magnetic field on Earth's surface */ 83#define MAGNETIC_FIELD_EARTH_MAX (60.0f) 84 85/** Minimum magnetic field on Earth's surface */ 86#define MAGNETIC_FIELD_EARTH_MIN (30.0f) 87 88 89/** 90 * status of each sensor 91 */ 92 93#define SENSOR_STATUS_UNRELIABLE 0 94#define SENSOR_STATUS_ACCURACY_LOW 1 95#define SENSOR_STATUS_ACCURACY_MEDIUM 2 96#define SENSOR_STATUS_ACCURACY_HIGH 3 97 98/** 99 * Definition of the axis 100 * ---------------------- 101 * 102 * This API is relative to the screen of the device in its default orientation, 103 * that is, if the device can be used in portrait or landscape, this API 104 * is only relative to the NATURAL orientation of the screen. In other words, 105 * the axis are not swapped when the device's screen orientation changes. 106 * Higher level services /may/ perform this transformation. 107 * 108 * x<0 x>0 109 * ^ 110 * | 111 * +-----------+--> y>0 112 * | | 113 * | | 114 * | | 115 * | | / z<0 116 * | | / 117 * | | / 118 * O-----------+/ 119 * |[] [ ] []/ 120 * +----------/+ y<0 121 * / 122 * / 123 * |/ z>0 (toward the sky) 124 * 125 * O: Origin (x=0,y=0,z=0) 126 * 127 * 128 * Orientation 129 * ----------- 130 * 131 * All values are angles in degrees. 132 * 133 * azimuth: angle between the magnetic north direction and the Y axis, around 134 * the Z axis (0<=azimuth<360). 135 * 0=North, 90=East, 180=South, 270=West 136 * 137 * pitch: Rotation around X axis (-180<=pitch<=180), with positive values when 138 * the z-axis moves toward the y-axis. 139 * 140 * roll: Rotation around Y axis (-90<=roll<=90), with positive values when 141 * the x-axis moves AWAY from the z-axis. 142 * 143 * Note: This definition is different from yaw, pitch and roll used in aviation 144 * where the X axis is along the long side of the plane (tail to nose). 145 * 146 * 147 * Acceleration 148 * ------------ 149 * 150 * All values are in SI units (m/s^2) and measure the acceleration of the 151 * device minus the force of gravity. 152 * 153 * x: Acceleration minus Gx on the x-axis 154 * y: Acceleration minus Gy on the y-axis 155 * z: Acceleration minus Gz on the z-axis 156 * 157 * Examples: 158 * When the device lies flat on a table and is pushed on its left side 159 * toward the right, the x acceleration value is positive. 160 * 161 * When the device lies flat on a table, the acceleration value is +9.81, 162 * which correspond to the acceleration of the device (0 m/s^2) minus the 163 * force of gravity (-9.81 m/s^2). 164 * 165 * When the device lies flat on a table and is pushed toward the sky, the 166 * acceleration value is greater than +9.81, which correspond to the 167 * acceleration of the device (+A m/s^2) minus the force of 168 * gravity (-9.81 m/s^2). 169 * 170 * 171 * Magnetic Field 172 * -------------- 173 * 174 * All values are in micro-Tesla (uT) and measure the ambient magnetic 175 * field in the X, Y and Z axis. 176 * 177 */ 178typedef struct { 179 union { 180 float v[3]; 181 struct { 182 float x; 183 float y; 184 float z; 185 }; 186 struct { 187 float azimuth; 188 float pitch; 189 float roll; 190 }; 191 }; 192 int8_t status; 193 uint8_t reserved[3]; 194} sensors_vec_t; 195 196/** 197 * Union of the various types of sensor data 198 * that can be returned. 199 */ 200typedef struct { 201 /* sensor identifier */ 202 int sensor; 203 204 union { 205 /* x,y,z values of the given sensor */ 206 sensors_vec_t vector; 207 208 /* orientation values are in degrees */ 209 sensors_vec_t orientation; 210 211 /* acceleration values are in meter per second per second (m/s^2) */ 212 sensors_vec_t acceleration; 213 214 /* magnetic vector values are in micro-Tesla (uT) */ 215 sensors_vec_t magnetic; 216 217 /* temperature is in degrees centigrade (Celsius) */ 218 float temperature; 219 220 /* distance in centimeters */ 221 float distance; 222 }; 223 224 /* time is in nanosecond */ 225 int64_t time; 226 227 uint32_t reserved; 228} sensors_data_t; 229 230 231struct sensor_t; 232 233/** 234 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM 235 * and the fields of this data structure must begin with hw_module_t 236 * followed by module specific information. 237 */ 238struct sensors_module_t { 239 struct hw_module_t common; 240 241 /** 242 * Enumerate all available sensors. The list is returned in "list". 243 * @return number of sensors in the list 244 */ 245 int (*get_sensors_list)(struct sensors_module_t* module, 246 struct sensor_t const** list); 247}; 248 249struct sensor_t { 250 /* name of this sensors */ 251 const char* name; 252 /* vendor of the hardware part */ 253 const char* vendor; 254 /* version of the hardware part + driver. The value of this field is 255 * left to the implementation and doesn't have to be monotonicaly 256 * increasing. 257 */ 258 int version; 259 /* handle that identifies this sensors. This handle is used to activate 260 * and deactivate this sensor. The value of the handle must be 8 bits 261 * in this version of the API. 262 */ 263 int handle; 264 /* this sensor's type. */ 265 int type; 266 /* maximaum range of this sensor's value in SI units */ 267 float maxRange; 268 /* smallest difference between two values reported by this sensor */ 269 float resolution; 270 /* rough estimate of this sensor's power consumption in mA */ 271 float power; 272 /* reserved fields, must be zero */ 273 void* reserved[9]; 274}; 275 276 277/** 278 * Every device data structure must begin with hw_device_t 279 * followed by module specific public methods and attributes. 280 */ 281struct sensors_control_device_t { 282 struct hw_device_t common; 283 284 /** 285 * Returns a native_handle_t, which will be the parameter to 286 * sensors_data_device_t::open_data(). 287 * The caller takes ownership of this handle. This is intended to be 288 * passed cross processes. 289 * 290 * @return a native_handle_t if successful, NULL on error 291 */ 292 native_handle_t* (*open_data_source)(struct sensors_control_device_t *dev); 293 294 /** Activate/deactivate one sensor. 295 * 296 * @param handle is the handle of the sensor to change. 297 * @param enabled set to 1 to enable, or 0 to disable the sensor. 298 * 299 * @return 0 on success, negative errno code otherwise 300 */ 301 int (*activate)(struct sensors_control_device_t *dev, 302 int handle, int enabled); 303 304 /** 305 * Set the delay between sensor events in ms 306 * 307 * @return 0 if successful, < 0 on error 308 */ 309 int (*set_delay)(struct sensors_control_device_t *dev, int32_t ms); 310 311 /** 312 * Causes sensors_data_device_t.poll() to return -EWOULDBLOCK immediately. 313 */ 314 int (*wake)(struct sensors_control_device_t *dev); 315}; 316 317struct sensors_data_device_t { 318 struct hw_device_t common; 319 320 /** 321 * Prepare to read sensor data. 322 * 323 * This routine does NOT take ownership of the handle 324 * and must not close it. Typically this routine would 325 * use a duplicate of the nh parameter. 326 * 327 * @param nh from sensors_control_open. 328 * 329 * @return 0 if successful, < 0 on error 330 */ 331 int (*data_open)(struct sensors_data_device_t *dev, native_handle_t* nh); 332 333 /** 334 * Caller has completed using the sensor data. 335 * The caller will not be blocked in sensors_data_poll 336 * when this routine is called. 337 * 338 * @return 0 if successful, < 0 on error 339 */ 340 int (*data_close)(struct sensors_data_device_t *dev); 341 342 /** 343 * Return sensor data for one of the enabled sensors. 344 * 345 * @return sensor handle for the returned data, 0x7FFFFFFF when 346 * sensors_control_device_t.wake() is called and -errno on error 347 * 348 */ 349 int (*poll)(struct sensors_data_device_t *dev, 350 sensors_data_t* data); 351}; 352 353 354/** convenience API for opening and closing a device */ 355 356static inline int sensors_control_open(const struct hw_module_t* module, 357 struct sensors_control_device_t** device) { 358 return module->methods->open(module, 359 SENSORS_HARDWARE_CONTROL, (struct hw_device_t**)device); 360} 361 362static inline int sensors_control_close(struct sensors_control_device_t* device) { 363 return device->common.close(&device->common); 364} 365 366static inline int sensors_data_open(const struct hw_module_t* module, 367 struct sensors_data_device_t** device) { 368 return module->methods->open(module, 369 SENSORS_HARDWARE_DATA, (struct hw_device_t**)device); 370} 371 372static inline int sensors_data_close(struct sensors_data_device_t* device) { 373 return device->common.close(&device->common); 374} 375 376 377__END_DECLS 378 379#endif // ANDROID_SENSORS_INTERFACE_H 380