1 /*
2 * Copyright (C) 2009 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 /* this implements a sensors hardware library for the Android emulator.
18 * the following code should be built as a shared library that will be
19 * placed into /system/lib/hw/sensors.goldfish.so
20 *
21 * it will be loaded by the code in hardware/libhardware/hardware.c
22 * which is itself called from com_android_server_SensorService.cpp
23 */
24
25 #define SENSORS_SERVICE_NAME "sensors"
26
27 #define LOG_TAG "Dummy_Sensors"
28
29 #include <unistd.h>
30 #include <fcntl.h>
31 #include <errno.h>
32 #include <string.h>
33 #include <log/log.h>
34 #include <cutils/sockets.h>
35 #include <hardware/sensors.h>
36 #include <pthread.h>
37
38 #if 0
39 #define D(...) ALOGD(__VA_ARGS__)
40 #else
41 #define D(...) ((void)0)
42 #endif
43
44 #define E(...) ALOGE(__VA_ARGS__)
45
46 /** SENSOR IDS AND NAMES
47 **/
48
49 #define MAX_NUM_SENSORS 8
50
51 #define SUPPORTED_SENSORS ((1<<MAX_NUM_SENSORS)-1)
52
53 #define ID_BASE SENSORS_HANDLE_BASE
54 #define ID_ACCELERATION (ID_BASE+0)
55 #define ID_MAGNETIC_FIELD (ID_BASE+1)
56 #define ID_ORIENTATION (ID_BASE+2)
57 #define ID_TEMPERATURE (ID_BASE+3)
58 #define ID_PROXIMITY (ID_BASE+4)
59 #define ID_LIGHT (ID_BASE+5)
60 #define ID_PRESSURE (ID_BASE+6)
61 #define ID_HUMIDITY (ID_BASE+7)
62
63 #define SENSORS_ACCELERATION (1 << ID_ACCELERATION)
64 #define SENSORS_MAGNETIC_FIELD (1 << ID_MAGNETIC_FIELD)
65 #define SENSORS_ORIENTATION (1 << ID_ORIENTATION)
66 #define SENSORS_TEMPERATURE (1 << ID_TEMPERATURE)
67 #define SENSORS_PROXIMITY (1 << ID_PROXIMITY)
68 #define SENSORS_LIGHT (1 << ID_LIGHT)
69 #define SENSORS_PRESSURE (1 << ID_PRESSURE)
70 #define SENSORS_HUMIDITY (1 << ID_HUMIDITY)
71
72 #define ID_CHECK(x) ((unsigned)((x) - ID_BASE) < MAX_NUM_SENSORS)
73
74 #define SENSORS_LIST \
75 SENSOR_(ACCELERATION,"acceleration") \
76 SENSOR_(MAGNETIC_FIELD,"magnetic-field") \
77 SENSOR_(ORIENTATION,"orientation") \
78 SENSOR_(TEMPERATURE,"temperature") \
79 SENSOR_(PROXIMITY,"proximity") \
80 SENSOR_(LIGHT, "light") \
81 SENSOR_(PRESSURE, "pressure") \
82 SENSOR_(HUMIDITY, "humidity")
83
84 static const struct {
85 const char* name;
86 int id; } _sensorIds[MAX_NUM_SENSORS] =
87 {
88 #define SENSOR_(x,y) { y, ID_##x },
89 SENSORS_LIST
90 #undef SENSOR_
91 };
92
93 static const char*
_sensorIdToName(int id)94 _sensorIdToName( int id )
95 {
96 int nn;
97 for (nn = 0; nn < MAX_NUM_SENSORS; nn++)
98 if (id == _sensorIds[nn].id)
99 return _sensorIds[nn].name;
100 return "<UNKNOWN>";
101 }
102
103 static int
_sensorIdFromName(const char * name)104 _sensorIdFromName( const char* name )
105 {
106 int nn;
107
108 if (name == NULL)
109 return -1;
110
111 for (nn = 0; nn < MAX_NUM_SENSORS; nn++)
112 if (!strcmp(name, _sensorIds[nn].name))
113 return _sensorIds[nn].id;
114
115 return -1;
116 }
117
118 /* return the current time in nanoseconds */
now_ns(void)119 static int64_t now_ns(void) {
120 struct timespec ts;
121 clock_gettime(CLOCK_MONOTONIC, &ts);
122 return (int64_t)ts.tv_sec * 1000000000 + ts.tv_nsec;
123 }
124
125 /** SENSORS POLL DEVICE
126 **
127 ** This one is used to read sensor data from the hardware.
128 ** We implement this by simply reading the data from the
129 ** emulator through the QEMUD channel.
130 **/
131
132 typedef struct SensorDevice {
133 struct sensors_poll_device_1 device;
134 sensors_event_t sensors[MAX_NUM_SENSORS];
135 uint32_t pendingSensors;
136 int64_t timeStart;
137 int64_t timeOffset;
138 uint32_t active_sensors;
139 int fd;
140 pthread_mutex_t lock;
141 } SensorDevice;
142
143 /* Grab the file descriptor to the emulator's sensors service pipe.
144 * This function returns a file descriptor on success, or -errno on
145 * failure, and assumes the SensorDevice instance's lock is held.
146 *
147 * This is needed because set_delay(), poll() and activate() can be called
148 * from different threads, and poll() is blocking.
149 *
150 * 1) On a first thread, de-activate() all sensors first, then call poll(),
151 * which results in the thread blocking.
152 *
153 * 2) On a second thread, slightly later, call set_delay() then activate()
154 * to enable the acceleration sensor.
155 *
156 * The system expects this to unblock the first thread which will receive
157 * new sensor events after the activate() call in 2).
158 *
159 * This cannot work if both threads don't use the same connection.
160 *
161 * TODO(digit): This protocol is brittle, implement another control channel
162 * for set_delay()/activate()/batch() when supporting HAL 1.3
163 */
sensor_device_get_fd_locked(SensorDevice * dev)164 static int sensor_device_get_fd_locked(SensorDevice* dev) {
165 /* Create connection to service on first call */
166 if (dev->fd < 0) {
167 int ret = -errno;
168 E("%s: Could not open connection to service: %s", __FUNCTION__,
169 strerror(-ret));
170 return ret;
171 }
172 return dev->fd;
173 }
174
175 /* Pick up one pending sensor event. On success, this returns the sensor
176 * id, and sets |*event| accordingly. On failure, i.e. if there are no
177 * pending events, return -EINVAL.
178 *
179 * Note: The device's lock must be acquired.
180 */
sensor_device_pick_pending_event_locked(SensorDevice * d,sensors_event_t * event)181 static int sensor_device_pick_pending_event_locked(SensorDevice* d,
182 sensors_event_t* event)
183 {
184 uint32_t mask = SUPPORTED_SENSORS & d->pendingSensors;
185
186 if (mask) {
187 uint32_t i = 31 - __builtin_clz(mask);
188
189 pthread_mutex_lock(&d->lock);
190 d->pendingSensors &= ~(1U << i);
191 *event = d->sensors[i];
192 event->sensor = i;
193 event->version = sizeof(*event);
194 pthread_mutex_unlock(&d->lock);
195 D("%s: %d [%f, %f, %f]", __FUNCTION__,
196 i,
197 event->data[0],
198 event->data[1],
199 event->data[2]);
200 return i;
201 }
202 E("No sensor to return!!! pendingSensors=0x%08x", d->pendingSensors);
203 // we may end-up in a busy loop, slow things down, just in case.
204 usleep(1000);
205 return -EINVAL;
206 }
207
sensor_device_close(struct hw_device_t * dev0)208 static int sensor_device_close(struct hw_device_t* dev0)
209 {
210 SensorDevice* dev = (void*)dev0;
211 // Assume that there are no other threads blocked on poll()
212 if (dev->fd >= 0) {
213 close(dev->fd);
214 dev->fd = -1;
215 }
216 pthread_mutex_destroy(&dev->lock);
217 free(dev);
218 return 0;
219 }
220
221 /* Return an array of sensor data. This function blocks until there is sensor
222 * related events to report. On success, it will write the events into the
223 * |data| array, which contains |count| items. The function returns the number
224 * of events written into the array, which shall never be greater than |count|.
225 * On error, return -errno code.
226 *
227 * Note that according to the sensor HAL [1], it shall never return 0!
228 *
229 * [1] http://source.android.com/devices/sensors/hal-interface.html
230 */
sensor_device_poll(struct sensors_poll_device_t * dev0,sensors_event_t * data,int count)231 static int sensor_device_poll(struct sensors_poll_device_t *dev0,
232 sensors_event_t* data, int count)
233 {
234 return -EIO;
235 }
236
sensor_device_activate(struct sensors_poll_device_t * dev0,int handle,int enabled)237 static int sensor_device_activate(struct sensors_poll_device_t *dev0,
238 int handle,
239 int enabled)
240 {
241 SensorDevice* dev = (void*)dev0;
242
243 D("%s: handle=%s (%d) enabled=%d", __FUNCTION__,
244 _sensorIdToName(handle), handle, enabled);
245
246 /* Sanity check */
247 if (!ID_CHECK(handle)) {
248 E("%s: bad handle ID", __FUNCTION__);
249 return -EINVAL;
250 }
251
252 /* Exit early if sensor is already enabled/disabled. */
253 uint32_t mask = (1U << handle);
254 uint32_t sensors = enabled ? mask : 0;
255
256 pthread_mutex_lock(&dev->lock);
257
258 uint32_t active = dev->active_sensors;
259 uint32_t new_sensors = (active & ~mask) | (sensors & mask);
260 uint32_t changed = active ^ new_sensors;
261
262 if (changed)
263 dev->active_sensors = new_sensors;
264
265 pthread_mutex_unlock(&dev->lock);
266 return 0;
267 }
268
sensor_device_default_flush(struct sensors_poll_device_1 * dev0,int handle)269 static int sensor_device_default_flush(
270 struct sensors_poll_device_1* dev0,
271 int handle) {
272
273 SensorDevice* dev = (void*)dev0;
274
275 D("%s: handle=%s (%d)", __FUNCTION__,
276 _sensorIdToName(handle), handle);
277
278 /* Sanity check */
279 if (!ID_CHECK(handle)) {
280 E("%s: bad handle ID", __FUNCTION__);
281 return -EINVAL;
282 }
283
284 pthread_mutex_lock(&dev->lock);
285 dev->sensors[handle].version = META_DATA_VERSION;
286 dev->sensors[handle].type = SENSOR_TYPE_META_DATA;
287 dev->sensors[handle].sensor = 0;
288 dev->sensors[handle].timestamp = 0;
289 dev->sensors[handle].meta_data.what = META_DATA_FLUSH_COMPLETE;
290 dev->pendingSensors |= (1U << handle);
291 pthread_mutex_unlock(&dev->lock);
292
293 return 0;
294 }
295
sensor_device_set_delay(struct sensors_poll_device_t * dev0,int handle __unused,int64_t ns)296 static int sensor_device_set_delay(struct sensors_poll_device_t *dev0,
297 int handle __unused,
298 int64_t ns)
299 {
300 return 0;
301 }
302
sensor_device_default_batch(struct sensors_poll_device_1 * dev,int sensor_handle,int flags,int64_t sampling_period_ns,int64_t max_report_latency_ns)303 static int sensor_device_default_batch(
304 struct sensors_poll_device_1* dev,
305 int sensor_handle,
306 int flags,
307 int64_t sampling_period_ns,
308 int64_t max_report_latency_ns) {
309 return sensor_device_set_delay(dev, sensor_handle, sampling_period_ns);
310 }
311
312 /** MODULE REGISTRATION SUPPORT
313 **
314 ** This is required so that hardware/libhardware/hardware.c
315 ** will dlopen() this library appropriately.
316 **/
317
318 /*
319 * the following is the list of all supported sensors.
320 * this table is used to build sSensorList declared below
321 * according to which hardware sensors are reported as
322 * available from the emulator (see get_sensors_list below)
323 *
324 * note: numerical values for maxRange/resolution/power for
325 * all sensors but light, pressure and humidity were
326 * taken from the reference AK8976A implementation
327 */
328 static const struct sensor_t sSensorListInit[] = {
329 { .name = "Accelerometer",
330 .vendor = "The Android Open Source Project",
331 .version = 1,
332 .handle = ID_ACCELERATION,
333 .type = SENSOR_TYPE_ACCELEROMETER,
334 .maxRange = 2.8f,
335 .resolution = 1.0f/4032.0f,
336 .power = 3.0f,
337 .minDelay = 10000,
338 .maxDelay = 60 * 1000 * 1000,
339 .fifoReservedEventCount = 0,
340 .fifoMaxEventCount = 0,
341 .stringType = 0,
342 .requiredPermission = 0,
343 .flags = SENSOR_FLAG_CONTINUOUS_MODE,
344 .reserved = {}
345 },
346 };
347
348 static struct sensor_t sSensorList[1];
349
sensors__get_sensors_list(struct sensors_module_t * module __unused,struct sensor_t const ** list)350 static int sensors__get_sensors_list(struct sensors_module_t* module __unused,
351 struct sensor_t const** list)
352 {
353 *list = sSensorList;
354
355 return 0;
356 }
357
358 static int
open_sensors(const struct hw_module_t * module,const char * name,struct hw_device_t ** device)359 open_sensors(const struct hw_module_t* module,
360 const char* name,
361 struct hw_device_t* *device)
362 {
363 int status = -EINVAL;
364
365 D("%s: name=%s", __FUNCTION__, name);
366
367 if (!strcmp(name, SENSORS_HARDWARE_POLL)) {
368 SensorDevice *dev = malloc(sizeof(*dev));
369
370 memset(dev, 0, sizeof(*dev));
371
372 dev->device.common.tag = HARDWARE_DEVICE_TAG;
373 dev->device.common.version = SENSORS_DEVICE_API_VERSION_1_3;
374 dev->device.common.module = (struct hw_module_t*) module;
375 dev->device.common.close = sensor_device_close;
376 dev->device.poll = sensor_device_poll;
377 dev->device.activate = sensor_device_activate;
378 dev->device.setDelay = sensor_device_set_delay;
379
380 // Version 1.3-specific functions
381 dev->device.batch = sensor_device_default_batch;
382 dev->device.flush = sensor_device_default_flush;
383
384 dev->fd = -1;
385 pthread_mutex_init(&dev->lock, NULL);
386
387 *device = &dev->device.common;
388 status = 0;
389 }
390 return status;
391 }
392
393
394 static struct hw_module_methods_t sensors_module_methods = {
395 .open = open_sensors
396 };
397
398 struct sensors_module_t HAL_MODULE_INFO_SYM = {
399 .common = {
400 .tag = HARDWARE_MODULE_TAG,
401 .version_major = 1,
402 .version_minor = 0,
403 .id = SENSORS_HARDWARE_MODULE_ID,
404 .name = "Dummy SENSORS Module",
405 .author = "The Android Open Source Project",
406 .methods = &sensors_module_methods,
407 },
408 .get_sensors_list = sensors__get_sensors_list
409 };
410