1 /*
2  * Copyright (C) 2016 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 #include <stdlib.h>
18 #include <string.h>
19 #include <timer.h>
20 #include <heap.h>
21 #include <plat/rtc.h>
22 #include <plat/syscfg.h>
23 #include <hostIntf.h>
24 #include <nanohubPacket.h>
25 #include <floatRt.h>
26 
27 #include <seos.h>
28 
29 #include <nanohub_math.h>
30 #include <sensors.h>
31 #include <limits.h>
32 
33 #define WINDOW_ORIENTATION_APP_VERSION  2
34 
35 #define LOG_TAG "[WO]"
36 
37 #define LOGV(fmt, ...) do { \
38         osLog(LOG_VERBOSE, LOG_TAG " " fmt,  ##__VA_ARGS__);  \
39     } while (0);
40 
41 #define LOGW(fmt, ...) do { \
42         osLog(LOG_WARN, LOG_TAG " " fmt,  ##__VA_ARGS__);  \
43     } while (0);
44 
45 #define LOGI(fmt, ...) do { \
46         osLog(LOG_INFO, LOG_TAG " " fmt,  ##__VA_ARGS__);  \
47     } while (0);
48 
49 #define LOGD(fmt, ...) do { \
50         if (DBG_ENABLE) {  \
51             osLog(LOG_DEBUG, LOG_TAG " " fmt,  ##__VA_ARGS__);  \
52         } \
53     } while (0);
54 
55 #define DBG_ENABLE  0
56 
57 #define ACCEL_MIN_RATE_HZ                  SENSOR_HZ(15) // 15 HZ
58 #define ACCEL_MAX_LATENCY_NS               40000000ull   // 40 ms in nsec
59 
60 // all time units in usec, angles in degrees
61 #define RADIANS_TO_DEGREES                              (180.0f / M_PI)
62 
63 #define NS2US(x) ((x) >> 10)   // convert nsec to approx usec
64 
65 #define PROPOSAL_MIN_SETTLE_TIME                        NS2US(40000000ull)       // 40 ms
66 #define PROPOSAL_MAX_SETTLE_TIME                        NS2US(400000000ull)      // 400 ms
67 #define PROPOSAL_TILT_ANGLE_KNEE                        20                       // 20 deg
68 #define PROPOSAL_SETTLE_TIME_SLOPE                      NS2US(12000000ull)       // 12 ms/deg
69 
70 #define PROPOSAL_MIN_TIME_SINCE_FLAT_ENDED              NS2US(500000000ull)      // 500 ms
71 #define PROPOSAL_MIN_TIME_SINCE_SWING_ENDED             NS2US(300000000ull)      // 300 ms
72 #define PROPOSAL_MIN_TIME_SINCE_ACCELERATION_ENDED      NS2US(500000000ull)      // 500 ms
73 
74 #define FLAT_ANGLE                      80
75 #define FLAT_TIME                       NS2US(1000000000ull)     // 1 sec
76 
77 #define SWING_AWAY_ANGLE_DELTA          20
78 #define SWING_TIME                      NS2US(300000000ull)      // 300 ms
79 
80 #define MAX_FILTER_DELTA_TIME           NS2US(1000000000ull)     // 1 sec
81 #define FILTER_TIME_CONSTANT            NS2US(200000000ull)      // 200 ms
82 
83 #define NEAR_ZERO_MAGNITUDE             1.0f        // m/s^2
84 #define ACCELERATION_TOLERANCE          4.0f
85 #define STANDARD_GRAVITY                9.8f
86 #define MIN_ACCELERATION_MAGNITUDE  (STANDARD_GRAVITY - ACCELERATION_TOLERANCE)
87 #define MAX_ACCELERATION_MAGNITUDE  (STANDARD_GRAVITY + ACCELERATION_TOLERANCE)
88 
89 #define MAX_TILT                        80
90 #define TILT_OVERHEAD_ENTER             -40
91 #define TILT_OVERHEAD_EXIT              -15
92 
93 #define ADJACENT_ORIENTATION_ANGLE_GAP  45
94 
95 // TILT_HISTORY_SIZE has to be greater than the time constant
96 // max(FLAT_TIME, SWING_TIME) multiplied by the highest accel sample rate after
97 // interpolation (1.0 / MIN_ACCEL_INTERVAL).
98 #define TILT_HISTORY_SIZE               64
99 #define TILT_REFERENCE_PERIOD           NS2US(1800000000000ull)  // 30 min
100 #define TILT_REFERENCE_BACKOFF          NS2US(300000000000ull)   // 5 min
101 
102 // Allow up to 2.5x of the desired rate (ACCEL_MIN_RATE_HZ)
103 // The concerns are complexity and (not so much) the size of tilt_history.
104 #define MIN_ACCEL_INTERVAL              NS2US(26666667ull)       // 26.7 ms for 37.5 Hz
105 
106 #define EVT_SENSOR_ACC_DATA_RDY sensorGetMyEventType(SENS_TYPE_ACCEL)
107 #define EVT_SENSOR_WIN_ORIENTATION_DATA_RDY sensorGetMyEventType(SENS_TYPE_WIN_ORIENTATION)
108 
109 static int8_t Tilt_Tolerance[4][2] = {
110     /* ROTATION_0   */ { -25, 70 },
111     /* ROTATION_90  */ { -25, 65 },
112     /* ROTATION_180 */ { -25, 60 },
113     /* ROTATION_270 */ { -25, 65 }
114 };
115 
116 struct WindowOrientationTask {
117     uint32_t tid;
118     uint32_t handle;
119     uint32_t accelHandle;
120 
121     uint64_t last_filtered_time;
122     struct TripleAxisDataPoint last_filtered_sample;
123 
124     uint64_t tilt_reference_time;
125     uint64_t accelerating_time;
126     uint64_t predicted_rotation_time;
127     uint64_t flat_time;
128     uint64_t swinging_time;
129 
130     uint32_t tilt_history_time[TILT_HISTORY_SIZE];
131     int tilt_history_index;
132     int8_t tilt_history[TILT_HISTORY_SIZE];
133 
134     int8_t current_rotation;
135     int8_t prev_valid_rotation;
136     int8_t proposed_rotation;
137     int8_t predicted_rotation;
138 
139     bool flat;
140     bool swinging;
141     bool accelerating;
142     bool overhead;
143 };
144 
145 static struct WindowOrientationTask mTask;
146 
147 static const struct SensorInfo mSi =
148 {
149     .sensorName = "Window Orientation",
150     .sensorType = SENS_TYPE_WIN_ORIENTATION,
151     .numAxis = NUM_AXIS_EMBEDDED,
152     .interrupt = NANOHUB_INT_NONWAKEUP,
153     .minSamples = 20
154 };
155 
isTiltAngleAcceptable(int rotation,int8_t tilt_angle)156 static bool isTiltAngleAcceptable(int rotation, int8_t tilt_angle)
157 {
158     return ((tilt_angle >= Tilt_Tolerance[rotation][0])
159                 && (tilt_angle <= Tilt_Tolerance[rotation][1]));
160 }
161 
isOrientationAngleAcceptable(int current_rotation,int rotation,int orientation_angle)162 static bool isOrientationAngleAcceptable(int current_rotation, int rotation,
163                                             int orientation_angle)
164 {
165     // If there is no current rotation, then there is no gap.
166     // The gap is used only to introduce hysteresis among advertised orientation
167     // changes to avoid flapping.
168     int lower_bound, upper_bound;
169 
170     LOGD("current %d, new %d, orientation %d",
171          (int)current_rotation, (int)rotation, (int)orientation_angle);
172 
173     if (current_rotation >= 0) {
174         // If the specified rotation is the same or is counter-clockwise
175         // adjacent to the current rotation, then we set a lower bound on the
176         // orientation angle.
177         // For example, if currentRotation is ROTATION_0 and proposed is
178         // ROTATION_90, then we want to check orientationAngle > 45 + GAP / 2.
179         if ((rotation == current_rotation)
180                 || (rotation == (current_rotation + 1) % 4)) {
181             lower_bound = rotation * 90 - 45
182                     + ADJACENT_ORIENTATION_ANGLE_GAP / 2;
183             if (rotation == 0) {
184                 if ((orientation_angle >= 315)
185                         && (orientation_angle < lower_bound + 360)) {
186                     return false;
187                 }
188             } else {
189                 if (orientation_angle < lower_bound) {
190                     return false;
191                 }
192             }
193         }
194 
195         // If the specified rotation is the same or is clockwise adjacent,
196         // then we set an upper bound on the orientation angle.
197         // For example, if currentRotation is ROTATION_0 and rotation is
198         // ROTATION_270, then we want to check orientationAngle < 315 - GAP / 2.
199         if ((rotation == current_rotation)
200                 || (rotation == (current_rotation + 3) % 4)) {
201             upper_bound = rotation * 90 + 45
202                     - ADJACENT_ORIENTATION_ANGLE_GAP / 2;
203             if (rotation == 0) {
204                 if ((orientation_angle <= 45)
205                         && (orientation_angle > upper_bound)) {
206                     return false;
207                 }
208             } else {
209                 if (orientation_angle > upper_bound) {
210                     return false;
211                 }
212             }
213         }
214     }
215     return true;
216 }
217 
isPredictedRotationAcceptable(uint64_t now,int8_t tilt_angle)218 static bool isPredictedRotationAcceptable(uint64_t now, int8_t tilt_angle)
219 {
220     // piecewise linear settle_time qualification:
221     // settle_time_needed =
222     // 1) PROPOSAL_MIN_SETTLE_TIME, for |tilt_angle| < PROPOSAL_TILT_ANGLE_KNEE.
223     // 2) linearly increasing with |tilt_angle| at slope PROPOSAL_SETTLE_TIME_SLOPE
224     // until it reaches PROPOSAL_MAX_SETTLE_TIME.
225     int abs_tilt = (tilt_angle >= 0) ? tilt_angle : -tilt_angle;
226     uint64_t settle_time_needed = PROPOSAL_MIN_SETTLE_TIME;
227     if (abs_tilt > PROPOSAL_TILT_ANGLE_KNEE) {
228         settle_time_needed += PROPOSAL_SETTLE_TIME_SLOPE
229             * (abs_tilt - PROPOSAL_TILT_ANGLE_KNEE);
230     }
231     if (settle_time_needed > PROPOSAL_MAX_SETTLE_TIME) {
232         settle_time_needed = PROPOSAL_MAX_SETTLE_TIME;
233     }
234     LOGD("settle_time_needed ~%llu (msec), settle_time ~%llu (msec)",
235          settle_time_needed >> 10, (now - mTask.predicted_rotation_time) >> 10);
236 
237     // The predicted rotation must have settled long enough.
238     if (now < mTask.predicted_rotation_time + settle_time_needed) {
239         LOGD("...rejected by settle_time");
240         return false;
241     }
242 
243     // The last flat state (time since picked up) must have been sufficiently
244     // long ago.
245     if (now < mTask.flat_time + PROPOSAL_MIN_TIME_SINCE_FLAT_ENDED) {
246         LOGD("...rejected by flat_time");
247         return false;
248     }
249 
250     // The last swing state (time since last movement to put down) must have
251     // been sufficiently long ago.
252     if (now < mTask.swinging_time + PROPOSAL_MIN_TIME_SINCE_SWING_ENDED) {
253         LOGD("...rejected by swing_time");
254         return false;
255     }
256 
257     // The last acceleration state must have been sufficiently long ago.
258     if (now < mTask.accelerating_time
259             + PROPOSAL_MIN_TIME_SINCE_ACCELERATION_ENDED) {
260         LOGD("...rejected by acceleration_time");
261         return false;
262     }
263 
264     // Looks good!
265     return true;
266 }
267 
clearPredictedRotation()268 static void clearPredictedRotation()
269 {
270     mTask.predicted_rotation = -1;
271     mTask.predicted_rotation_time = 0;
272 }
273 
clearTiltHistory()274 static void clearTiltHistory()
275 {
276     mTask.tilt_history_time[0] = 0;
277     mTask.tilt_history_index = 1;
278     mTask.tilt_reference_time = 0;
279 }
280 
reset()281 static void reset()
282 {
283     mTask.last_filtered_time = 0;
284     mTask.proposed_rotation = -1;
285 
286     mTask.flat_time = 0;
287     mTask.flat = false;
288 
289     mTask.swinging_time = 0;
290     mTask.swinging = false;
291 
292     mTask.accelerating_time = 0;
293     mTask.accelerating = false;
294 
295     mTask.overhead = false;
296 
297     clearPredictedRotation();
298     clearTiltHistory();
299 }
300 
updatePredictedRotation(uint64_t now,int rotation)301 static void updatePredictedRotation(uint64_t now, int rotation)
302 {
303     if (mTask.predicted_rotation != rotation) {
304         mTask.predicted_rotation = rotation;
305         mTask.predicted_rotation_time = now;
306     }
307 }
308 
isAccelerating(float magnitude)309 static bool isAccelerating(float magnitude)
310 {
311     return ((magnitude < MIN_ACCELERATION_MAGNITUDE)
312                 || (magnitude > MAX_ACCELERATION_MAGNITUDE));
313 }
314 
addTiltHistoryEntry(uint64_t now,int8_t tilt)315 static void addTiltHistoryEntry(uint64_t now, int8_t tilt)
316 {
317     uint64_t old_reference_time, delta;
318     size_t i;
319     int index;
320 
321     if (mTask.tilt_reference_time == 0) {
322         // set reference_time after reset()
323 
324         mTask.tilt_reference_time = now - 1;
325     } else if (mTask.tilt_reference_time + TILT_REFERENCE_PERIOD < now) {
326         // uint32_t tilt_history_time[] is good up to 71 min (2^32 * 1e-6 sec).
327         // proactively shift reference_time every 30 min,
328         // all history entries are within 4.3sec interval (15Hz x 64 samples)
329 
330         old_reference_time = mTask.tilt_reference_time;
331         mTask.tilt_reference_time = now - TILT_REFERENCE_BACKOFF;
332 
333         delta = mTask.tilt_reference_time - old_reference_time;
334         for (i = 0; i < TILT_HISTORY_SIZE; ++i) {
335             mTask.tilt_history_time[i] = (mTask.tilt_history_time[i] > delta)
336                 ? (mTask.tilt_history_time[i] - delta) : 0;
337         }
338     }
339 
340     index = mTask.tilt_history_index;
341     mTask.tilt_history[index] = tilt;
342     mTask.tilt_history_time[index] = now - mTask.tilt_reference_time;
343 
344     index = ((index + 1) == TILT_HISTORY_SIZE) ? 0 : (index + 1);
345     mTask.tilt_history_index = index;
346     mTask.tilt_history_time[index] = 0;
347 }
348 
nextTiltHistoryIndex(int index)349 static int nextTiltHistoryIndex(int index)
350 {
351     int next = (index == 0) ? (TILT_HISTORY_SIZE - 1): (index - 1);
352     return ((mTask.tilt_history_time[next] != 0) ? next : -1);
353 }
354 
isFlat(uint64_t now)355 static bool isFlat(uint64_t now)
356 {
357     int i = mTask.tilt_history_index;
358     for (; (i = nextTiltHistoryIndex(i)) >= 0;) {
359         if (mTask.tilt_history[i] < FLAT_ANGLE) {
360             break;
361         }
362         if (mTask.tilt_reference_time + mTask.tilt_history_time[i] + FLAT_TIME <= now) {
363             // Tilt has remained greater than FLAT_ANGLE for FLAT_TIME.
364             return true;
365         }
366     }
367     return false;
368 }
369 
isSwinging(uint64_t now,int8_t tilt)370 static bool isSwinging(uint64_t now, int8_t tilt)
371 {
372     int i = mTask.tilt_history_index;
373     for (; (i = nextTiltHistoryIndex(i)) >= 0;) {
374         if (mTask.tilt_reference_time + mTask.tilt_history_time[i] + SWING_TIME
375                 < now) {
376             break;
377         }
378         if (mTask.tilt_history[i] + SWING_AWAY_ANGLE_DELTA <= tilt) {
379             // Tilted away by SWING_AWAY_ANGLE_DELTA within SWING_TIME.
380             // This is one-sided protection. No latency will be added when
381             // picking up the device and rotating.
382             return true;
383         }
384     }
385     return false;
386 }
387 
add_samples(struct TripleAxisDataEvent * ev)388 static bool add_samples(struct TripleAxisDataEvent *ev)
389 {
390     int i, tilt_tmp;
391     int orientation_angle, nearest_rotation;
392     float x, y, z, alpha, magnitude;
393     uint64_t now_nsec = ev->referenceTime, now;
394     uint64_t then, time_delta;
395     struct TripleAxisDataPoint *last_sample;
396     size_t sampleCnt = ev->samples[0].firstSample.numSamples;
397     bool skip_sample;
398     bool accelerating, flat, swinging;
399     bool change_detected;
400     int8_t old_proposed_rotation, proposed_rotation;
401     int8_t tilt_angle;
402 
403     for (i = 0; i < sampleCnt; i++) {
404 
405         x = ev->samples[i].x;
406         y = ev->samples[i].y;
407         z = ev->samples[i].z;
408 
409         // Apply a low-pass filter to the acceleration up vector in cartesian space.
410         // Reset the orientation listener state if the samples are too far apart in time.
411 
412         now_nsec += i > 0 ? ev->samples[i].deltaTime : 0;
413         now = NS2US(now_nsec); // convert to ~usec
414 
415         last_sample = &mTask.last_filtered_sample;
416         then = mTask.last_filtered_time;
417         time_delta = now - then;
418 
419         if ((now < then) || (now > then + MAX_FILTER_DELTA_TIME)) {
420             reset();
421             skip_sample = true;
422         } else {
423             // alpha is the weight on the new sample
424             alpha = floatFromUint64(time_delta) / floatFromUint64(FILTER_TIME_CONSTANT + time_delta);
425             x = alpha * (x - last_sample->x) + last_sample->x;
426             y = alpha * (y - last_sample->y) + last_sample->y;
427             z = alpha * (z - last_sample->z) + last_sample->z;
428 
429             skip_sample = false;
430         }
431 
432         // poor man's interpolator for reduced complexity:
433         // drop samples when input sampling rate is 2.5x higher than requested
434         if (!skip_sample && (time_delta < MIN_ACCEL_INTERVAL)) {
435             skip_sample = true;
436         } else {
437             mTask.last_filtered_time = now;
438             mTask.last_filtered_sample.x = x;
439             mTask.last_filtered_sample.y = y;
440             mTask.last_filtered_sample.z = z;
441         }
442 
443         accelerating = false;
444         flat = false;
445         swinging = false;
446 
447         if (!skip_sample) {
448             // Calculate the magnitude of the acceleration vector.
449             magnitude = sqrtf(x * x + y * y + z * z);
450 
451             if (magnitude < NEAR_ZERO_MAGNITUDE) {
452                 LOGD("Ignoring sensor data, magnitude too close to zero.");
453                 clearPredictedRotation();
454             } else {
455                 // Determine whether the device appears to be undergoing
456                 // external acceleration.
457                 if (isAccelerating(magnitude)) {
458                     accelerating = true;
459                     mTask.accelerating_time = now;
460                 }
461 
462                 // Calculate the tilt angle.
463                 // This is the angle between the up vector and the x-y plane
464                 // (the plane of the screen) in a range of [-90, 90] degrees.
465                 //  -90 degrees: screen horizontal and facing the ground (overhead)
466                 //    0 degrees: screen vertical
467                 //   90 degrees: screen horizontal and facing the sky (on table)
468                 tilt_tmp = (int)(asinf(z / magnitude) * RADIANS_TO_DEGREES);
469                 tilt_tmp = (tilt_tmp > 127) ? 127 : tilt_tmp;
470                 tilt_tmp = (tilt_tmp < -128) ? -128 : tilt_tmp;
471                 tilt_angle = tilt_tmp;
472                 addTiltHistoryEntry(now, tilt_angle);
473 
474                 // Determine whether the device appears to be flat or swinging.
475                 if (isFlat(now)) {
476                     flat = true;
477                     mTask.flat_time = now;
478                 }
479                 if (isSwinging(now, tilt_angle)) {
480                     swinging = true;
481                     mTask.swinging_time = now;
482                 }
483 
484                 // If the tilt angle is too close to horizontal then we cannot
485                 // determine the orientation angle of the screen.
486                 if (tilt_angle <= TILT_OVERHEAD_ENTER) {
487                     mTask.overhead = true;
488                 } else if (tilt_angle >= TILT_OVERHEAD_EXIT) {
489                     mTask.overhead = false;
490                 }
491 
492                 if (mTask.overhead) {
493                     LOGD("Ignoring sensor data, device is overhead: %d", (int)tilt_angle);
494                     clearPredictedRotation();
495                 } else if (fabsf(tilt_angle) > MAX_TILT) {
496                     LOGD("Ignoring sensor data, tilt angle too high: %d", (int)tilt_angle);
497                     clearPredictedRotation();
498                 } else {
499                     // Calculate the orientation angle.
500                     // This is the angle between the x-y projection of the up
501                     // vector onto the +y-axis, increasing clockwise in a range
502                     // of [0, 360] degrees.
503                     orientation_angle = (int)(-atan2f(-x, y) * RADIANS_TO_DEGREES);
504                     if (orientation_angle < 0) {
505                         // atan2 returns [-180, 180]; normalize to [0, 360]
506                         orientation_angle += 360;
507                     }
508 
509                     // Find the nearest rotation.
510                     nearest_rotation = (orientation_angle + 45) / 90;
511                     if (nearest_rotation == 4) {
512                         nearest_rotation = 0;
513                     }
514                     // Determine the predicted orientation.
515                     if (isTiltAngleAcceptable(nearest_rotation, tilt_angle)
516                         && isOrientationAngleAcceptable(mTask.current_rotation,
517                                                            nearest_rotation,
518                                                            orientation_angle)) {
519                         LOGD("Predicted: tilt %d, orientation %d, predicted %d",
520                              (int)tilt_angle, (int)orientation_angle, (int)mTask.predicted_rotation);
521                         updatePredictedRotation(now, nearest_rotation);
522                     } else {
523                         LOGD("Ignoring sensor data, no predicted rotation: "
524                              "tilt %d, orientation %d",
525                              (int)tilt_angle, (int)orientation_angle);
526                         clearPredictedRotation();
527                     }
528                 }
529             }
530 
531             mTask.flat = flat;
532             mTask.swinging = swinging;
533             mTask.accelerating = accelerating;
534 
535             // Determine new proposed rotation.
536             old_proposed_rotation = mTask.proposed_rotation;
537             if ((mTask.predicted_rotation < 0)
538                     || isPredictedRotationAcceptable(now, tilt_angle)) {
539 
540                 mTask.proposed_rotation = mTask.predicted_rotation;
541             }
542             proposed_rotation = mTask.proposed_rotation;
543 
544             if ((proposed_rotation != old_proposed_rotation)
545                     && (proposed_rotation >= 0)) {
546                 mTask.current_rotation = proposed_rotation;
547 
548                 change_detected = (proposed_rotation != mTask.prev_valid_rotation);
549                 mTask.prev_valid_rotation = proposed_rotation;
550 
551                 if (change_detected) {
552                     return true;
553                 }
554             }
555         }
556     }
557 
558     return false;
559 }
560 
561 
windowOrientationPower(bool on,void * cookie)562 static bool windowOrientationPower(bool on, void *cookie)
563 {
564     if (on == false && mTask.accelHandle != 0) {
565         sensorRelease(mTask.tid, mTask.accelHandle);
566         mTask.accelHandle = 0;
567         osEventUnsubscribe(mTask.tid, EVT_SENSOR_ACC_DATA_RDY);
568     }
569 
570     sensorSignalInternalEvt(mTask.handle, SENSOR_INTERNAL_EVT_POWER_STATE_CHG, on, 0);
571 
572     return true;
573 }
574 
windowOrientationSetRate(uint32_t rate,uint64_t latency,void * cookie)575 static bool windowOrientationSetRate(uint32_t rate, uint64_t latency, void *cookie)
576 {
577     int i;
578 
579     if (mTask.accelHandle == 0) {
580         for (i = 0; sensorFind(SENS_TYPE_ACCEL, i, &mTask.accelHandle) != NULL; i++) {
581             if (sensorRequest(mTask.tid, mTask.accelHandle, ACCEL_MIN_RATE_HZ, ACCEL_MAX_LATENCY_NS)) {
582                 // clear hysteresis
583                 mTask.current_rotation = -1;
584                 mTask.prev_valid_rotation = -1;
585                 reset();
586                 osEventSubscribe(mTask.tid, EVT_SENSOR_ACC_DATA_RDY);
587                 break;
588             }
589         }
590     }
591 
592     if (mTask.accelHandle != 0)
593         sensorSignalInternalEvt(mTask.handle, SENSOR_INTERNAL_EVT_RATE_CHG, rate, latency);
594 
595     return true;
596 }
597 
windowOrientationFirmwareUpload(void * cookie)598 static bool windowOrientationFirmwareUpload(void *cookie)
599 {
600     sensorSignalInternalEvt(mTask.handle, SENSOR_INTERNAL_EVT_FW_STATE_CHG,
601             1, 0);
602     return true;
603 }
604 
windowOrientationFlush(void * cookie)605 static bool windowOrientationFlush(void *cookie)
606 {
607     return osEnqueueEvt(sensorGetMyEventType(SENS_TYPE_WIN_ORIENTATION), SENSOR_DATA_EVENT_FLUSH, NULL);
608 }
609 
windowOrientationHandleEvent(uint32_t evtType,const void * evtData)610 static void windowOrientationHandleEvent(uint32_t evtType, const void* evtData)
611 {
612     struct TripleAxisDataEvent *ev;
613     union EmbeddedDataPoint sample;
614     bool rotation_changed;
615 
616     if (evtData == SENSOR_DATA_EVENT_FLUSH)
617         return;
618 
619     switch (evtType) {
620     case EVT_SENSOR_ACC_DATA_RDY:
621         ev = (struct TripleAxisDataEvent *)evtData;
622         rotation_changed = add_samples(ev);
623 
624         if (rotation_changed) {
625             LOGV("rotation changed to: ******* %d *******\n",
626                  (int)mTask.proposed_rotation);
627 
628             // send a single int32 here so no memory alloc/free needed.
629             sample.idata = mTask.proposed_rotation;
630             if (!osEnqueueEvt(EVT_SENSOR_WIN_ORIENTATION_DATA_RDY, sample.vptr, NULL)) {
631                 LOGW("osEnqueueEvt failure");
632             }
633         }
634         break;
635     }
636 }
637 
638 static const struct SensorOps mSops =
639 {
640     .sensorPower = windowOrientationPower,
641     .sensorFirmwareUpload = windowOrientationFirmwareUpload,
642     .sensorSetRate = windowOrientationSetRate,
643     .sensorFlush = windowOrientationFlush,
644 };
645 
window_orientation_start(uint32_t tid)646 static bool window_orientation_start(uint32_t tid)
647 {
648     mTask.tid = tid;
649 
650     mTask.current_rotation = -1;
651     mTask.prev_valid_rotation = -1;
652     reset();
653 
654     mTask.handle = sensorRegister(&mSi, &mSops, NULL, true);
655 
656     return true;
657 }
658 
windowOrientationEnd()659 static void windowOrientationEnd()
660 {
661 }
662 
663 INTERNAL_APP_INIT(
664         APP_ID_MAKE(NANOHUB_VENDOR_GOOGLE, 3),
665         WINDOW_ORIENTATION_APP_VERSION,
666         window_orientation_start,
667         windowOrientationEnd,
668         windowOrientationHandleEvent);
669