transform.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation.
   3  */
   4
   5 #include <stdlib.h>
   6 #include <math.h>
   7 #include <utils/Log.h>
   8 #include <cutils/properties.h>
   9 #include <hardware/sensors.h>
  10 #include "calibration.h"
  11 #include "common.h"
  12 #include "description.h"
  13 #include "transform.h"
  14 #include "utils.h"
  15 #include "filtering.h"
  16
  17 /*----------------------------------------------------------------------------*/
  18
  19 /* Macros related to Intel Sensor Hub */
  20
  21 #define GRAVITY 9.80665f
  22
  23 /* 720 LSG = 1G */
  24 #define LSG                         (1024.0)
  25 #define NUMOFACCDATA                (8.0)
  26
  27 /* conversion of acceleration data to SI units (m/s^2) */
  28 #define CONVERT_A                   (GRAVITY_EARTH / LSG / NUMOFACCDATA)
  29 #define CONVERT_A_X(x)              ((float(x)/1000) * (GRAVITY * -1.0))
  30 #define CONVERT_A_Y(x)              ((float(x)/1000) * (GRAVITY * 1.0))
  31 #define CONVERT_A_Z(x)              ((float(x)/1000) * (GRAVITY * 1.0))
  32
  33 /* conversion of magnetic data to uT units */
  34 #define CONVERT_M                   (1.0/6.6)
  35 #define CONVERT_M_X                 (-CONVERT_M)
  36 #define CONVERT_M_Y                 (-CONVERT_M)
  37 #define CONVERT_M_Z                 (CONVERT_M)
  38
  39 #define CONVERT_GAUSS_TO_MICROTESLA(x)        ((x) * 100 )
  40
  41 /* conversion of orientation data to degree units */
  42 #define CONVERT_O                   (1.0/64)
  43 #define CONVERT_O_A                 (CONVERT_O)
  44 #define CONVERT_O_P                 (CONVERT_O)
  45 #define CONVERT_O_R                 (-CONVERT_O)
  46
  47 /*conversion of gyro data to SI units (radian/sec) */
  48 #define CONVERT_GYRO                (2000.0/32767*M_PI/180)
  49 #define CONVERT_GYRO_X              (-CONVERT_GYRO)
  50 #define CONVERT_GYRO_Y              (-CONVERT_GYRO)
  51 #define CONVERT_GYRO_Z              (CONVERT_GYRO)
  52
  53 #define BIT(x) (1 << (x))
  54
  55 inline unsigned int set_bit_range(int start, int end)
  56 {
  57     int i;
  58     unsigned int value = 0;
  59
  60     for (i = start; i < end; ++i)
  61         value |= BIT(i);
  62     return value;
  63 }
  64
  65 inline float convert_from_vtf_format(int size, int exponent, unsigned int value)
  66 {
  67     int divider=1;
  68     int i;
  69     float sample;
  70     int mul = 1.0;
  71
  72     value = value & set_bit_range(0, size*8);
  73     if (value & BIT(size*8-1)) {
  74         value =  ((1LL << (size*8)) - value);
  75         mul = -1.0;
  76     }
  77     sample = value * 1.0;
  78     if (exponent < 0) {
  79         exponent = abs(exponent);
  80         for (i = 0; i < exponent; ++i) {
  81             divider = divider*10;
  82         }
  83         return mul * sample/divider;
  84     } else {
  85         return mul * sample * pow(10.0, exponent);
  86     }
  87 }
  88
  89 /* Platform sensor orientation */
  90 #define DEF_ORIENT_ACCEL_X                   -1
  91 #define DEF_ORIENT_ACCEL_Y                   -1
  92 #define DEF_ORIENT_ACCEL_Z                   -1
  93
  94 #define DEF_ORIENT_GYRO_X                   1
  95 #define DEF_ORIENT_GYRO_Y                   1
  96 #define DEF_ORIENT_GYRO_Z                   1
  97
  98 /* G to m/s2 */
  99 #define CONVERT_FROM_VTF16(s,d,x)      (convert_from_vtf_format(s,d,x))
 100 #define CONVERT_A_G_VTF16E14_X(s,d,x)  (DEF_ORIENT_ACCEL_X *\
 101                                         convert_from_vtf_format(s,d,x)*GRAVITY)
 102 #define CONVERT_A_G_VTF16E14_Y(s,d,x)  (DEF_ORIENT_ACCEL_Y *\
 103                                         convert_from_vtf_format(s,d,x)*GRAVITY)
 104 #define CONVERT_A_G_VTF16E14_Z(s,d,x)  (DEF_ORIENT_ACCEL_Z *\
 105                                         convert_from_vtf_format(s,d,x)*GRAVITY)
 106
 107 /* Degree/sec to radian/sec */
 108 #define CONVERT_G_D_VTF16E14_X(s,d,x)  (DEF_ORIENT_GYRO_X *\
 109                                         convert_from_vtf_format(s,d,x) * \
 110                                         M_PI/180)
 111 #define CONVERT_G_D_VTF16E14_Y(s,d,x)  (DEF_ORIENT_GYRO_Y *\
 112                                         convert_from_vtf_format(s,d,x) * \
 113                                         M_PI/180)
 114 #define CONVERT_G_D_VTF16E14_Z(s,d,x)  (DEF_ORIENT_GYRO_Z *\
 115                                         convert_from_vtf_format(s,d,x) * \
 116                                         M_PI/180)
 117
 118 /* Milli gauss to micro tesla */
 119 #define CONVERT_M_MG_VTF16E14_X(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 120 #define CONVERT_M_MG_VTF16E14_Y(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 121 #define CONVERT_M_MG_VTF16E14_Z(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 122
 123
 124 /*----------------------------------------------------------------------------*/
 125
 126 static int64_t sample_as_int64(unsigned char* sample, struct datum_info_t* type)
 127 {
 128         uint64_t u64;
 129         int i;
 130         int zeroed_bits = type->storagebits - type->realbits;
 131         uint64_t sign_mask;
 132         uint64_t value_mask;
 133
 134         u64 = 0;
 135
 136         if (type->endianness == 'b')
 137                 for (i=0; i<type->storagebits/8; i++)
 138                         u64 = (u64 << 8) | sample[i];
 139         else
 140                 for (i=type->storagebits/8 - 1; i>=0; i--)
 141                         u64 = (u64 << 8) | sample[i];
 142
 143         u64 = (u64 >> type->shift) & (~0ULL >> zeroed_bits);
 144
 145         if (type->sign == 'u')
 146                 return (int64_t) u64; /* We don't handle unsigned 64 bits int */
 147
 148         /* Signed integer */
 149
 150         switch (type->realbits) {
 151                 case 0 ... 1:
 152                         return 0;
 153
 154                 case 8:
 155                         return (int64_t) (int8_t) u64;
 156
 157                 case 16:
 158                         return (int64_t) (int16_t) u64;
 159
 160                 case 32:
 161                         return (int64_t) (int32_t) u64;
 162
 163                 case 64:
 164                         return (int64_t) u64;
 165
 166                 default:
 167                         sign_mask = 1 << (type->realbits-1);
 168                         value_mask = sign_mask - 1;
 169
 170                         if (u64 & sign_mask)
 171                                 /* Negative value: return 2-complement */
 172                                 return - ((~u64 & value_mask) + 1);
 173                         else
 174                                 return (int64_t) u64; /* Positive value */
 175         }
 176 }
 177
 178
 179 static void reorder_fields(float* data, unsigned char map[MAX_CHANNELS])
 180 {
 181         int i;
 182         float temp[MAX_CHANNELS];
 183
 184         for (i=0; i<MAX_CHANNELS; i++)
 185                 temp[i] = data[map[i]];
 186
 187         for (i=0; i<MAX_CHANNELS; i++)
 188                 data[i] = temp[i];
 189 }
 190
 191
 192 static void clamp_gyro_readings_to_zero (int s, struct sensors_event_t* data)
 193 {
 194         float x, y, z;
 195         float near_zero;
 196
 197         x = data->data[0];
 198         y = data->data[1];
 199         z = data->data[2];
 200
 201
 202         /* If we're calibrated, don't filter out as much */
 203         if (sensor_info[s].cal_level > 0)
 204                 near_zero = 0.02; /* rad/s */
 205         else
 206                 near_zero = 0.1;
 207
 208         /* If motion on all axes is small enough */
 209         if (fabs(x) < near_zero && fabs(y) < near_zero && fabs(z) < near_zero) {
 210
 211                 /*
 212                  * Report that we're not moving at all... but not exactly zero
 213                  * as composite sensors (orientation, rotation vector) don't
 214                  * seem to react very well to it.
 215                  */
 216
 217                 data->data[0] *= 0.000001;
 218                 data->data[1] *= 0.000001;
 219                 data->data[2] *= 0.000001;
 220         }
 221 }
 222
 223 static void process_event_gyro_uncal(int s, int i, struct sensors_event_t* data)
 224 {
 225         struct gyro_cal* gyro_data = NULL;
 226
 227         if (sensor_info[s].type == SENSOR_TYPE_GYROSCOPE) {
 228                 gyro_data = (struct gyro_cal*) sensor_info[s].cal_data;
 229                 memcpy(&sensor_info[i].sample, data, sizeof(struct sensors_event_t));
 230
 231                 sensor_info[i].sample.type = SENSOR_TYPE_GYROSCOPE_UNCALIBRATED;
 232                 sensor_info[i].sample.sensor = s;
 233
 234                 sensor_info[i].sample.data[0] = data->data[0] + gyro_data->bias_x;
 235                 sensor_info[i].sample.data[1] = data->data[1] + gyro_data->bias_y;
 236                 sensor_info[i].sample.data[2] = data->data[2] + gyro_data->bias_z;
 237
 238                 sensor_info[i].sample.uncalibrated_gyro.bias[0] = gyro_data->bias_x;
 239                 sensor_info[i].sample.uncalibrated_gyro.bias[1] = gyro_data->bias_y;
 240                 sensor_info[i].sample.uncalibrated_gyro.bias[2] = gyro_data->bias_z;
 241
 242                 sensor_info[i].report_pending = 1;
 243         }
 244 }
 245
 246 static void process_event(int s, struct sensors_event_t* data)
 247 {
 248         /*
 249          * This gets the real event (post process - calibration, filtering & co.)
 250          * and makes it into a virtual one.
 251          * The specific processing function for each sensor will populate the
 252          * necessary fields and set up the report pending flag.
 253          */
 254
 255          int i;
 256
 257          /* Go through out virtual sensors and check if we can use this event */
 258          for (i = 0; i < sensor_count; i++) {
 259                 switch (sensor_info[i].type) {
 260                         case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
 261                                 process_event_gyro_uncal(s, i, data);
 262                         break;
 263
 264                         default:
 265                         break;
 266                 }
 267         }
 268 }
 269
 270 static int finalize_sample_default (int s, struct sensors_event_t* data)
 271 {
 272         /* Swap fields if we have a custom channel ordering on this sensor */
 273         if (sensor_info[s].quirks & QUIRK_FIELD_ORDERING)
 274                 reorder_fields(data->data, sensor_info[s].order);
 275
 276         sensor_info[s].event_count++;
 277         switch (sensor_info[s].type) {
 278                 case SENSOR_TYPE_ACCELEROMETER:
 279                         /* Always consider the accelerometer accurate */
 280                         data->acceleration.status = SENSOR_STATUS_ACCURACY_HIGH;
 281                         if (sensor_info[s].quirks & QUIRK_NOISY)
 282                                 denoise(s, data);
 283                         break;
 284
 285                 case SENSOR_TYPE_MAGNETIC_FIELD:
 286                         calibrate_compass (data, &sensor_info[s]);
 287                         if (sensor_info[s].quirks & QUIRK_NOISY)
 288                                 denoise(s, data);
 289                         break;
 290
 291                 case SENSOR_TYPE_GYROSCOPE:
 292
 293                         /*
 294                          * Report medium accuracy by default ; higher accuracy
 295                          * levels will be reported once, and if, we achieve
 296                          * calibration.
 297                          */
 298                         data->gyro.status = SENSOR_STATUS_ACCURACY_MEDIUM;
 299
 300                         /*
 301                          * We're only trying to calibrate data from continuously
 302                          * firing gyroscope drivers, as motion based ones use
 303                          * movement thresholds that may lead us to incorrectly
 304                          * estimate bias.
 305                          */
 306                         if (sensor_info[s].selected_trigger !=
 307                                 sensor_info[s].motion_trigger_name)
 308                                         calibrate_gyro(data, &sensor_info[s]);
 309
 310                         /*
 311                          * For noisy sensors drop a few samples to make sure we
 312                          * have at least GYRO_MIN_SAMPLES events in the
 313                          * filtering queue. This improves mean and std dev.
 314                          */
 315                         if (sensor_info[s].quirks & QUIRK_NOISY) {
 316                                 if (sensor_info[s].selected_trigger !=
 317                                     sensor_info[s].motion_trigger_name &&
 318                                     sensor_info[s].event_count<GYRO_MIN_SAMPLES)
 319                                                 return 0;
 320
 321                                 denoise(s, data);
 322                         }
 323
 324                         /* Clamp near zero moves to (0,0,0) if appropriate */
 325                         clamp_gyro_readings_to_zero(s, data);
 326                         break;
 327
 328                 case SENSOR_TYPE_LIGHT:
 329                 case SENSOR_TYPE_AMBIENT_TEMPERATURE:
 330                 case SENSOR_TYPE_TEMPERATURE:
 331                         /* Only keep two decimals for these readings */
 332                         data->data[0] = 0.01 * ((int) (data->data[0] * 100));
 333
 334                         /* ... fall through ... */
 335
 336                 case SENSOR_TYPE_PROXIMITY:
 337                         /*
 338                          * These are on change sensors ; drop the sample if it
 339                          * has the same value as the previously reported one.
 340                          */
 341                         if (data->data[0] == sensor_info[s].prev_val)
 342                                 return 0;
 343
 344                         sensor_info[s].prev_val = data->data[0];
 345                         break;
 346         }
 347         /* If there are active virtual sensors depending on this one - process the event */
 348         if (sensor_info[s].ref_count)
 349                 process_event(s, data);
 350         /* We will drop samples if the sensor is not directly enabled */
 351         if (!sensor_info[s].directly_enabled)
 352                 return 0;
 353
 354         return 1; /* Return sample to Android */
 355 }
 356
 357
 358 static float transform_sample_default(int s, int c, unsigned char* sample_data)
 359 {
 360         struct datum_info_t* sample_type = &sensor_info[s].channel[c].type_info;
 361         int64_t              s64 = sample_as_int64(sample_data, sample_type);
 362         float scale = sensor_info[s].scale ?
 363                         sensor_info[s].scale : sensor_info[s].channel[c].scale;
 364
 365         /* In case correction has been requested using properties, apply it */
 366         scale *= sensor_info[s].channel[c].opt_scale;
 367
 368         /* Apply default scaling rules */
 369         return (sensor_info[s].offset + s64) * scale;
 370 }
 371
 372
 373 static int finalize_sample_ISH (int s, struct sensors_event_t* data)
 374 {
 375         float pitch, roll, yaw;
 376
 377         /* Swap fields if we have a custom channel ordering on this sensor */
 378         if (sensor_info[s].quirks & QUIRK_FIELD_ORDERING)
 379                 reorder_fields(data->data, sensor_info[s].order);
 380
 381         if (sensor_info[s].type == SENSOR_TYPE_ORIENTATION) {
 382
 383                 pitch = data->data[0];
 384                 roll = data->data[1];
 385                 yaw = data->data[2];
 386
 387                 data->data[0] = 360.0 - yaw;
 388                 data->data[1] = -pitch;
 389                 data->data[2] = -roll;
 390         }
 391
 392         /* Add this event to our global records, for filtering purposes */
 393         record_sample(s, data);
 394
 395         return 1; /* Return sample to Android */
 396 }
 397
 398
 399 static float transform_sample_ISH (int s, int c, unsigned char* sample_data)
 400 {
 401         struct datum_info_t* sample_type = &sensor_info[s].channel[c].type_info;
 402         int val         = (int) sample_as_int64(sample_data, sample_type);
 403         float correction;
 404         int data_bytes  = (sample_type->realbits)/8;
 405         int exponent    = sensor_info[s].offset;
 406
 407         /* In case correction has been requested using properties, apply it */
 408         correction = sensor_info[s].channel[c].opt_scale;
 409
 410         switch (sensor_info[s].type) {
 411                 case SENSOR_TYPE_ACCELEROMETER:
 412                         switch (c) {
 413                                 case 0:
 414                                         return  correction *
 415                                                 CONVERT_A_G_VTF16E14_X(
 416                                                 data_bytes, exponent, val);
 417
 418                                 case 1:
 419                                         return  correction *
 420                                                 CONVERT_A_G_VTF16E14_Y(
 421                                                 data_bytes, exponent, val);
 422
 423                                 case 2:
 424                                         return  correction *
 425                                                 CONVERT_A_G_VTF16E14_Z(
 426                                                 data_bytes, exponent, val);
 427                         }
 428                         break;
 429
 430
 431                 case SENSOR_TYPE_GYROSCOPE:
 432                         switch (c) {
 433                                 case 0:
 434                                         return  correction *
 435                                                 CONVERT_G_D_VTF16E14_X(
 436                                                 data_bytes, exponent, val);
 437
 438                                 case 1:
 439                                         return  correction *
 440                                                 CONVERT_G_D_VTF16E14_Y(
 441                                                 data_bytes, exponent, val);
 442
 443                                 case 2:
 444                                         return  correction *
 445                                                 CONVERT_G_D_VTF16E14_Z(
 446                                                 data_bytes, exponent, val);
 447                         }
 448                         break;
 449
 450                 case SENSOR_TYPE_MAGNETIC_FIELD:
 451                         switch (c) {
 452                                 case 0:
 453                                         return  correction *
 454                                                 CONVERT_M_MG_VTF16E14_X(
 455                                                 data_bytes, exponent, val);
 456
 457                                 case 1:
 458                                         return  correction *
 459                                                 CONVERT_M_MG_VTF16E14_Y(
 460                                                 data_bytes, exponent, val);
 461
 462                                 case 2:
 463                                         return  correction *
 464                                                 CONVERT_M_MG_VTF16E14_Z(
 465                                                 data_bytes, exponent, val);
 466                         }
 467                         break;
 468
 469                 case SENSOR_TYPE_LIGHT:
 470                                 return (float) val;
 471
 472                 case SENSOR_TYPE_ORIENTATION:
 473                         return  correction * convert_from_vtf_format(
 474                                                 data_bytes, exponent, val);
 475
 476                 case SENSOR_TYPE_ROTATION_VECTOR:
 477                         return  correction * convert_from_vtf_format(
 478                                                 data_bytes, exponent, val);
 479         }
 480
 481         return 0;
 482 }
 483
 484
 485 void select_transform (int s)
 486 {
 487         char prop_name[PROP_NAME_MAX];
 488         char prop_val[PROP_VALUE_MAX];
 489         int i                   = sensor_info[s].catalog_index;
 490         const char *prefix      = sensor_catalog[i].tag;
 491
 492         sprintf(prop_name, PROP_BASE, prefix, "transform");
 493
 494         if (property_get(prop_name, prop_val, "")) {
 495                 if (!strcmp(prop_val, "ISH")) {
 496                         ALOGI(  "Using Intel Sensor Hub semantics on %s\n",
 497                                 sensor_info[s].friendly_name);
 498
 499                         sensor_info[s].ops.transform = transform_sample_ISH;
 500                         sensor_info[s].ops.finalize = finalize_sample_ISH;
 501                         return;
 502                 }
 503         }
 504
 505         sensor_info[s].ops.transform = transform_sample_default;
 506         sensor_info[s].ops.finalize = finalize_sample_default;
 507 }
 508
 509
 510 float acquire_immediate_value(int s, int c)
 511 {
 512         char sysfs_path[PATH_MAX];
 513         float val;
 514         int ret;
 515         int dev_num = sensor_info[s].dev_num;
 516         int i = sensor_info[s].catalog_index;
 517         const char* raw_path = sensor_catalog[i].channel[c].raw_path;
 518         const char* input_path = sensor_catalog[i].channel[c].input_path;
 519         float scale = sensor_info[s].scale ?
 520                         sensor_info[s].scale : sensor_info[s].channel[c].scale;
 521         float offset = sensor_info[s].offset;
 522         int sensor_type = sensor_catalog[i].type;
 523         float correction;
 524
 525         /* In case correction has been requested using properties, apply it */
 526         correction = sensor_info[s].channel[c].opt_scale;
 527
 528         /* Acquire a sample value for sensor s / channel c through sysfs */
 529
 530         if (input_path[0]) {
 531                 sprintf(sysfs_path, BASE_PATH "%s", dev_num, input_path);
 532                 ret = sysfs_read_float(sysfs_path, &val);
 533
 534                 if (!ret) {
 535                         return val * correction;
 536                 }
 537         };
 538
 539         if (!raw_path[0])
 540                 return 0;
 541
 542         sprintf(sysfs_path, BASE_PATH "%s", dev_num, raw_path);
 543         ret = sysfs_read_float(sysfs_path, &val);
 544
 545         if (ret == -1)
 546                 return 0;
 547
 548         /*
 549         There is no transform ops defined yet for Raw sysfs values
 550         Use this function to perform transformation as well.
 551         */
 552         if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
 553                 return  CONVERT_GAUSS_TO_MICROTESLA ((val + offset) * scale) *
 554                         correction;
 555
 556         return (val + offset) * scale * correction;
 557 }