2 * Copyright (C) 2008 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #ifndef ANDROID_SENSORS_INTERFACE_H
18 #define ANDROID_SENSORS_INTERFACE_H
21 #include <sys/cdefs.h>
22 #include <sys/types.h>
24 #include <hardware/hardware.h>
25 #include <cutils/native_handle.h>
30 * The id of this module
32 #define SENSORS_HARDWARE_MODULE_ID "sensors"
35 * Name of the sensors device to open
37 #define SENSORS_HARDWARE_CONTROL "control"
38 #define SENSORS_HARDWARE_DATA "data"
39 #define SENSORS_HARDWARE_POLL "poll"
42 * Handles must be higher than SENSORS_HANDLE_BASE and must be unique.
43 * A Handle identifies a given sensors. The handle is used to activate
44 * and/or deactivate sensors.
45 * In this version of the API there can only be 256 handles.
47 #define SENSORS_HANDLE_BASE 0
48 #define SENSORS_HANDLE_BITS 8
49 #define SENSORS_HANDLE_COUNT (1<<SENSORS_HANDLE_BITS)
55 #define SENSOR_TYPE_ACCELEROMETER 1
56 #define SENSOR_TYPE_MAGNETIC_FIELD 2
57 #define SENSOR_TYPE_ORIENTATION 3
58 #define SENSOR_TYPE_GYROSCOPE 4
59 #define SENSOR_TYPE_LIGHT 5
60 #define SENSOR_TYPE_PRESSURE 6
61 #define SENSOR_TYPE_TEMPERATURE 7
62 #define SENSOR_TYPE_PROXIMITY 8
65 * Values returned by the accelerometer in various locations in the universe.
66 * all values are in SI units (m/s^2)
69 #define GRAVITY_SUN (275.0f)
70 #define GRAVITY_EARTH (9.80665f)
72 /** Maximum magnetic field on Earth's surface */
73 #define MAGNETIC_FIELD_EARTH_MAX (60.0f)
75 /** Minimum magnetic field on Earth's surface */
76 #define MAGNETIC_FIELD_EARTH_MIN (30.0f)
80 * status of each sensor
83 #define SENSOR_STATUS_UNRELIABLE 0
84 #define SENSOR_STATUS_ACCURACY_LOW 1
85 #define SENSOR_STATUS_ACCURACY_MEDIUM 2
86 #define SENSOR_STATUS_ACCURACY_HIGH 3
89 * Definition of the axis
90 * ----------------------
92 * This API is relative to the screen of the device in its default orientation,
93 * that is, if the device can be used in portrait or landscape, this API
94 * is only relative to the NATURAL orientation of the screen. In other words,
95 * the axis are not swapped when the device's screen orientation changes.
96 * Higher level services /may/ perform this transformation.
101 * +-----------+--> y>0
113 * |/ z>0 (toward the sky)
115 * O: Origin (x=0,y=0,z=0)
121 * All values are angles in degrees.
123 * azimuth: angle between the magnetic north direction and the Y axis, around
124 * the Z axis (0<=azimuth<360).
125 * 0=North, 90=East, 180=South, 270=West
127 * pitch: Rotation around X axis (-180<=pitch<=180), with positive values when
128 * the z-axis moves toward the y-axis.
130 * roll: Rotation around Y axis (-90<=roll<=90), with positive values when
131 * the x-axis moves towards the z-axis.
133 * Note: For historical reasons the roll angle is positive in the clockwise
134 * direction (mathematically speaking, it should be positive in the
135 * counter-clockwise direction):
141 * | | roll: rotation around Y axis
144 * note that +Y == -roll
148 * Note: This definition is different from yaw, pitch and roll used in aviation
149 * where the X axis is along the long side of the plane (tail to nose).
155 * All values are in SI units (m/s^2) and measure the acceleration of the
156 * device minus the force of gravity.
158 * x: Acceleration minus Gx on the x-axis
159 * y: Acceleration minus Gy on the y-axis
160 * z: Acceleration minus Gz on the z-axis
163 * When the device lies flat on a table and is pushed on its left side
164 * toward the right, the x acceleration value is positive.
166 * When the device lies flat on a table, the acceleration value is +9.81,
167 * which correspond to the acceleration of the device (0 m/s^2) minus the
168 * force of gravity (-9.81 m/s^2).
170 * When the device lies flat on a table and is pushed toward the sky, the
171 * acceleration value is greater than +9.81, which correspond to the
172 * acceleration of the device (+A m/s^2) minus the force of
173 * gravity (-9.81 m/s^2).
179 * All values are in micro-Tesla (uT) and measure the ambient magnetic
180 * field in the X, Y and Z axis.
185 * The distance value is measured in centimeters. Note that some proximity
186 * sensors only support a binary "close" or "far" measurement. In this case,
187 * the sensor should report its maxRange value in the "far" state and a value
188 * less than maxRange in the "near" state.
193 * The light sensor value is returned in SI lux units.
215 * Union of the various types of sensor data
216 * that can be returned.
219 /* sensor identifier */
223 /* x,y,z values of the given sensor */
224 sensors_vec_t vector;
226 /* orientation values are in degrees */
227 sensors_vec_t orientation;
229 /* acceleration values are in meter per second per second (m/s^2) */
230 sensors_vec_t acceleration;
232 /* magnetic vector values are in micro-Tesla (uT) */
233 sensors_vec_t magnetic;
235 /* temperature is in degrees centigrade (Celsius) */
238 /* distance in centimeters */
241 /* light in SI lux units */
245 /* time is in nanosecond */
254 * Union of the various types of sensor data
255 * that can be returned.
257 typedef struct sensors_event_t {
258 /* must be sizeof(struct sensors_event_t) */
261 /* sensor identifier */
270 /* time is in nanosecond */
276 /* acceleration values are in meter per second per second (m/s^2) */
277 sensors_vec_t acceleration;
279 /* magnetic vector values are in micro-Tesla (uT) */
280 sensors_vec_t magnetic;
282 /* orientation values are in degrees */
283 sensors_vec_t orientation;
285 /* temperature is in degrees centigrade (Celsius) */
288 /* distance in centimeters */
291 /* light in SI lux units */
294 uint32_t reserved1[4];
302 * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
303 * and the fields of this data structure must begin with hw_module_t
304 * followed by module specific information.
306 struct sensors_module_t {
307 struct hw_module_t common;
310 * Enumerate all available sensors. The list is returned in "list".
311 * @return number of sensors in the list
313 int (*get_sensors_list)(struct sensors_module_t* module,
314 struct sensor_t const** list);
318 /* name of this sensors */
320 /* vendor of the hardware part */
322 /* version of the hardware part + driver. The value of this field is
323 * left to the implementation and doesn't have to be monotonically
327 /* handle that identifies this sensors. This handle is used to activate
328 * and deactivate this sensor. The value of the handle must be 8 bits
329 * in this version of the API.
332 /* this sensor's type. */
334 /* maximaum range of this sensor's value in SI units */
336 /* smallest difference between two values reported by this sensor */
338 /* rough estimate of this sensor's power consumption in mA */
340 /* reserved fields, must be zero */
346 * Every device data structure must begin with hw_device_t
347 * followed by module specific public methods and attributes.
349 struct sensors_poll_device_t {
350 struct hw_device_t common;
352 /** Activate/deactivate one sensor.
354 * @param handle is the handle of the sensor to change.
355 * @param enabled set to 1 to enable, or 0 to disable the sensor.
357 * @return 0 on success, negative errno code otherwise
359 int (*activate)(struct sensors_poll_device_t *dev,
360 int handle, int enabled);
363 * Set the delay between sensor events in nanoseconds for a given sensor
365 * @return 0 if successful, < 0 on error
367 int (*setDelay)(struct sensors_poll_device_t *dev,
368 int handle, int64_t ns);
371 * Returns an array of sensor data.
373 * @return the number of events read on success, or -errno in case of an error.
376 int (*poll)(struct sensors_poll_device_t *dev,
377 sensors_event_t* data, int count);
381 struct sensors_control_device_t {
382 struct hw_device_t common;
385 * Returns a native_handle_t, which will be the parameter to
386 * sensors_data_device_t::open_data().
387 * The caller takes ownership of this handle. This is intended to be
388 * passed cross processes.
390 * @return a native_handle_t if successful, NULL on error
392 native_handle_t* (*open_data_source)(struct sensors_control_device_t *dev);
395 * Releases any resources that were created by open_data_source.
396 * This call is optional and can be NULL if not implemented
399 * @return 0 if successful, < 0 on error
401 int (*close_data_source)(struct sensors_control_device_t *dev);
403 /** Activate/deactivate one sensor.
405 * @param handle is the handle of the sensor to change.
406 * @param enabled set to 1 to enable, or 0 to disable the sensor.
408 * @return 0 on success, negative errno code otherwise
410 int (*activate)(struct sensors_control_device_t *dev,
411 int handle, int enabled);
414 * Set the delay between sensor events in ms
416 * @return 0 if successful, < 0 on error
418 int (*set_delay)(struct sensors_control_device_t *dev, int32_t ms);
421 * Causes sensors_data_device_t.poll() to return -EWOULDBLOCK immediately.
423 int (*wake)(struct sensors_control_device_t *dev);
426 struct sensors_data_device_t {
427 struct hw_device_t common;
430 * Prepare to read sensor data.
432 * This routine does NOT take ownership of the handle
433 * and must not close it. Typically this routine would
434 * use a duplicate of the nh parameter.
436 * @param nh from sensors_control_open.
438 * @return 0 if successful, < 0 on error
440 int (*data_open)(struct sensors_data_device_t *dev, native_handle_t* nh);
443 * Caller has completed using the sensor data.
444 * The caller will not be blocked in sensors_data_poll
445 * when this routine is called.
447 * @return 0 if successful, < 0 on error
449 int (*data_close)(struct sensors_data_device_t *dev);
452 * Return sensor data for one of the enabled sensors.
454 * @return sensor handle for the returned data, 0x7FFFFFFF when
455 * sensors_control_device_t.wake() is called and -errno on error
458 int (*poll)(struct sensors_data_device_t *dev,
459 sensors_data_t* data);
463 /** convenience API for opening and closing a device */
465 static inline int sensors_open(const struct hw_module_t* module,
466 struct sensors_poll_device_t** device) {
467 return module->methods->open(module,
468 SENSORS_HARDWARE_POLL, (struct hw_device_t**)device);
471 static inline int sensors_close(struct sensors_poll_device_t* device) {
472 return device->common.close(&device->common);
475 static inline int sensors_control_open(const struct hw_module_t* module,
476 struct sensors_control_device_t** device) {
477 return module->methods->open(module,
478 SENSORS_HARDWARE_CONTROL, (struct hw_device_t**)device);
481 static inline int sensors_control_close(struct sensors_control_device_t* device) {
482 return device->common.close(&device->common);
485 static inline int sensors_data_open(const struct hw_module_t* module,
486 struct sensors_data_device_t** device) {
487 return module->methods->open(module,
488 SENSORS_HARDWARE_DATA, (struct hw_device_t**)device);
491 static inline int sensors_data_close(struct sensors_data_device_t* device) {
492 return device->common.close(&device->common);
498 #endif // ANDROID_SENSORS_INTERFACE_H