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
  16 /*----------------------------------------------------------------------------*/
  17
  18 /* Macros related to Intel Sensor Hub */
  19
  20 #define GRAVITY 9.80665f
  21
  22 /* 720 LSG = 1G */
  23 #define LSG                         (1024.0f)
  24 #define NUMOFACCDATA                (8.0f)
  25
  26 /* conversion of acceleration data to SI units (m/s^2) */
  27 #define CONVERT_A                   (GRAVITY_EARTH / LSG / NUMOFACCDATA)
  28 #define CONVERT_A_X(x)              ((float(x)/1000) * (GRAVITY * -1.0))
  29 #define CONVERT_A_Y(x)              ((float(x)/1000) * (GRAVITY * 1.0))
  30 #define CONVERT_A_Z(x)              ((float(x)/1000) * (GRAVITY * 1.0))
  31
  32 /* conversion of magnetic data to uT units */
  33 #define CONVERT_M                   (1.0f/6.6f)
  34 #define CONVERT_M_X                 (-CONVERT_M)
  35 #define CONVERT_M_Y                 (-CONVERT_M)
  36 #define CONVERT_M_Z                 (CONVERT_M)
  37
  38 #define CONVERT_GAUSS_TO_MICROTESLA(x)        ( (x) * 100 )
  39
  40 /* conversion of orientation data to degree units */
  41 #define CONVERT_O                   (1.0f/64.0f)
  42 #define CONVERT_O_A                 (CONVERT_O)
  43 #define CONVERT_O_P                 (CONVERT_O)
  44 #define CONVERT_O_R                 (-CONVERT_O)
  45
  46 /*conversion of gyro data to SI units (radian/sec) */
  47 #define CONVERT_GYRO                ((2000.0f/32767.0f)*((float)M_PI / 180.0f))
  48 #define CONVERT_GYRO_X              (-CONVERT_GYRO)
  49 #define CONVERT_GYRO_Y              (-CONVERT_GYRO)
  50 #define CONVERT_GYRO_Z              (CONVERT_GYRO)
  51
  52 #define BIT(x) (1 << (x))
  53
  54 inline unsigned int set_bit_range(int start, int end)
  55 {
  56     int i;
  57     unsigned int value = 0;
  58
  59     for (i = start; i < end; ++i)
  60         value |= BIT(i);
  61     return value;
  62 }
  63
  64 inline float convert_from_vtf_format(int size, int exponent, unsigned int value)
  65 {
  66     int divider=1;
  67     int i;
  68     float sample;
  69     int mul = 1.0;
  70
  71     value = value & set_bit_range(0, size*8);
  72     if (value & BIT(size*8-1)) {
  73         value =  ((1LL << (size*8)) - value);
  74         mul = -1.0;
  75     }
  76     sample = value * 1.0;
  77     if (exponent < 0) {
  78         exponent = abs(exponent);
  79         for (i = 0; i < exponent; ++i) {
  80             divider = divider*10;
  81         }
  82         return mul * sample/divider;
  83     } else {
  84         return mul * sample * pow(10.0, exponent);
  85     }
  86 }
  87
  88 // Platform sensor orientation
  89 #define DEF_ORIENT_ACCEL_X                   -1
  90 #define DEF_ORIENT_ACCEL_Y                   -1
  91 #define DEF_ORIENT_ACCEL_Z                   -1
  92
  93 #define DEF_ORIENT_GYRO_X                   1
  94 #define DEF_ORIENT_GYRO_Y                   1
  95 #define DEF_ORIENT_GYRO_Z                   1
  96
  97 // G to m/s2
  98 #define CONVERT_FROM_VTF16(s,d,x)      (convert_from_vtf_format(s,d,x))
  99 #define CONVERT_A_G_VTF16E14_X(s,d,x)  (DEF_ORIENT_ACCEL_X *\
 100                                         convert_from_vtf_format(s,d,x)*GRAVITY)
 101 #define CONVERT_A_G_VTF16E14_Y(s,d,x)  (DEF_ORIENT_ACCEL_Y *\
 102                                         convert_from_vtf_format(s,d,x)*GRAVITY)
 103 #define CONVERT_A_G_VTF16E14_Z(s,d,x)  (DEF_ORIENT_ACCEL_Z *\
 104                                         convert_from_vtf_format(s,d,x)*GRAVITY)
 105
 106 // Degree/sec to radian/sec
 107 #define CONVERT_G_D_VTF16E14_X(s,d,x)  (DEF_ORIENT_GYRO_X *\
 108                                         convert_from_vtf_format(s,d,x) * \
 109                                         ((float)M_PI/180.0f))
 110 #define CONVERT_G_D_VTF16E14_Y(s,d,x)  (DEF_ORIENT_GYRO_Y *\
 111                                         convert_from_vtf_format(s,d,x) * \
 112                                         ((float)M_PI/180.0f))
 113 #define CONVERT_G_D_VTF16E14_Z(s,d,x)  (DEF_ORIENT_GYRO_Z *\
 114                                         convert_from_vtf_format(s,d,x) * \
 115                                         ((float)M_PI/180.0f))
 116
 117 // Milli gauss to micro tesla
 118 #define CONVERT_M_MG_VTF16E14_X(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 119 #define CONVERT_M_MG_VTF16E14_Y(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 120 #define CONVERT_M_MG_VTF16E14_Z(s,d,x) (convert_from_vtf_format(s,d,x)/10)
 121
 122
 123 /*----------------------------------------------------------------------------*/
 124
 125 static int64_t sample_as_int64(unsigned char* sample, struct datum_info_t* type)
 126 {
 127         uint64_t u64;
 128         int i;
 129         int zeroed_bits = type->storagebits - type->realbits;
 130         uint64_t sign_mask;
 131         uint64_t value_mask;
 132
 133         u64 = 0;
 134
 135         if (type->endianness == 'b')
 136                 for (i=0; i<type->storagebits/8; i++)
 137                         u64 = (u64 << 8) | sample[i];
 138         else
 139                 for (i=type->storagebits/8 - 1; i>=0; i--)
 140                         u64 = (u64 << 8) | sample[i];
 141
 142         u64 = (u64 >> type->shift) & (~0ULL >> zeroed_bits);
 143
 144         if (type->sign == 'u')
 145                 return (int64_t) u64; /* We don't handle unsigned 64 bits int */
 146
 147         /* Signed integer */
 148
 149         switch (type->realbits) {
 150                 case 0 ... 1:
 151                         return 0;
 152
 153                 case 8:
 154                         return (int64_t) (int8_t) u64;
 155
 156                 case 16:
 157                         return (int64_t) (int16_t) u64;
 158
 159                 case 32:
 160                         return (int64_t) (int32_t) u64;
 161
 162                 case 64:
 163                         return (int64_t) u64;
 164
 165                 default:
 166                         sign_mask = 1 << (type->realbits-1);
 167                         value_mask = sign_mask - 1;
 168
 169                         if (u64 & sign_mask)
 170                                 /* Negative value: return 2-complement */
 171                                 return - ((~u64 & value_mask) + 1);
 172                         else
 173                                 return (int64_t) u64; /* Positive value */
 174         }
 175 }
 176
 177
 178 static void reorder_fields(float* data, unsigned char map[MAX_CHANNELS])
 179 {
 180         int i;
 181         float temp[MAX_CHANNELS];
 182
 183         for (i=0; i<MAX_CHANNELS; i++)
 184                 temp[i] = data[map[i]];
 185
 186         for (i=0; i<MAX_CHANNELS; i++)
 187                 data[i] = temp[i];
 188 }
 189
 190
 191 static int finalize_sample_default(int s, struct sensors_event_t* data)
 192 {
 193         int i           = sensor_info[s].catalog_index;
 194         int sensor_type = sensor_catalog[i].type;
 195
 196         /* Swap fields if we have a custom channel ordering on this sensor */
 197         if (sensor_info[s].quirks & QUIRK_FIELD_ORDERING)
 198                 reorder_fields(data->data, sensor_info[s].order);
 199
 200         switch (sensor_type) {
 201                 case SENSOR_TYPE_ACCELEROMETER:
 202                         break;
 203
 204                 case SENSOR_TYPE_MAGNETIC_FIELD:
 205                         calibrate_compass (data, &sensor_info[s], get_timestamp());
 206                         break;
 207
 208                 case SENSOR_TYPE_GYROSCOPE:
 209                 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
 210                         calibrate_gyro(data, &sensor_info[s]);
 211                         break;
 212
 213                 case SENSOR_TYPE_LIGHT:
 214                 case SENSOR_TYPE_AMBIENT_TEMPERATURE:
 215                 case SENSOR_TYPE_TEMPERATURE:
 216                         /* Only keep two decimals for these readings */
 217                         data->data[0] = 0.01 * ((int) (data->data[0] * 100));
 218
 219                         /* ... fall through ... */
 220
 221                 case SENSOR_TYPE_PROXIMITY:
 222                         /*
 223                          * These are on change sensors ; drop the sample if it
 224                          * has the same value as the previously reported one.
 225                          */
 226                         if (data->data[0] == sensor_info[s].prev_val)
 227                                 return 0;
 228
 229                         sensor_info[s].prev_val = data->data[0];
 230                         break;
 231         }
 232
 233         return 1; /* Return sample to Android */
 234 }
 235
 236
 237 static float transform_sample_default(int s, int c, unsigned char* sample_data)
 238 {
 239         struct datum_info_t* sample_type = &sensor_info[s].channel[c].type_info;
 240         int64_t              s64 = sample_as_int64(sample_data, sample_type);
 241         float scale = sensor_info[s].scale ?
 242                         sensor_info[s].scale : sensor_info[s].channel[c].scale;
 243
 244         /* In case correction has been requested using properties, apply it */
 245         scale *= sensor_info[s].channel[c].opt_scale;
 246
 247         /* Apply default scaling rules */
 248         return (sensor_info[s].offset + s64) * scale;
 249 }
 250
 251
 252 static int finalize_sample_ISH(int s, struct sensors_event_t* data)
 253 {
 254         int i           = sensor_info[s].catalog_index;
 255         int sensor_type = sensor_catalog[i].type;
 256         float pitch, roll, yaw;
 257
 258         /* Swap fields if we have a custom channel ordering on this sensor */
 259         if (sensor_info[s].quirks & QUIRK_FIELD_ORDERING)
 260                 reorder_fields(data->data, sensor_info[s].order);
 261
 262         if (sensor_type == SENSOR_TYPE_ORIENTATION) {
 263
 264                 pitch = data->data[0];
 265                 roll = data->data[1];
 266                 yaw = data->data[2];
 267
 268                 data->data[0] = 360.0 - yaw;
 269                 data->data[1] = -pitch;
 270                 data->data[2] = -roll;
 271         }
 272
 273         return 1; /* Return sample to Android */
 274 }
 275
 276
 277 static float transform_sample_ISH(int s, int c, unsigned char* sample_data)
 278 {
 279         struct datum_info_t* sample_type = &sensor_info[s].channel[c].type_info;
 280         int val         = (int) sample_as_int64(sample_data, sample_type);
 281         int i           = sensor_info[s].catalog_index;
 282         int sensor_type = sensor_catalog[i].type;
 283         float correction;
 284         int data_bytes  = (sample_type->realbits)/8;
 285         int exponent    = sensor_info[s].offset;
 286
 287         /* In case correction has been requested using properties, apply it */
 288         correction = sensor_info[s].channel[c].opt_scale;
 289
 290         switch (sensor_type) {
 291                 case SENSOR_TYPE_ACCELEROMETER:
 292                         switch (c) {
 293                                 case 0:
 294                                         return  correction *
 295                                                 CONVERT_A_G_VTF16E14_X(
 296                                                 data_bytes, exponent, val);
 297
 298                                 case 1:
 299                                         return  correction *
 300                                                 CONVERT_A_G_VTF16E14_Y(
 301                                                 data_bytes, exponent, val);
 302
 303                                 case 2:
 304                                         return  correction *
 305                                                 CONVERT_A_G_VTF16E14_Z(
 306                                                 data_bytes, exponent, val);
 307                         }
 308                         break;
 309
 310
 311                 case SENSOR_TYPE_GYROSCOPE:
 312                         switch (c) {
 313                                 case 0:
 314                                         return  correction *
 315                                                 CONVERT_G_D_VTF16E14_X(
 316                                                 data_bytes, exponent, val);
 317
 318                                 case 1:
 319                                         return  correction *
 320                                                 CONVERT_G_D_VTF16E14_Y(
 321                                                 data_bytes, exponent, val);
 322
 323                                 case 2:
 324                                         return  correction *
 325                                                 CONVERT_G_D_VTF16E14_Z(
 326                                                 data_bytes, exponent, val);
 327                         }
 328                         break;
 329
 330                 case SENSOR_TYPE_MAGNETIC_FIELD:
 331                         switch (c) {
 332                                 case 0:
 333                                         return  correction *
 334                                                 CONVERT_M_MG_VTF16E14_X(
 335                                                 data_bytes, exponent, val);
 336
 337                                 case 1:
 338                                         return  correction *
 339                                                 CONVERT_M_MG_VTF16E14_Y(
 340                                                 data_bytes, exponent, val);
 341
 342                                 case 2:
 343                                         return  correction *
 344                                                 CONVERT_M_MG_VTF16E14_Z(
 345                                                 data_bytes, exponent, val);
 346                         }
 347                         break;
 348
 349                 case SENSOR_TYPE_LIGHT:
 350                                 return (float) val;
 351
 352                 case SENSOR_TYPE_ORIENTATION:
 353                         return  correction * convert_from_vtf_format(
 354                                                 data_bytes, exponent, val);
 355
 356                 case SENSOR_TYPE_ROTATION_VECTOR:
 357                         return  correction * convert_from_vtf_format(
 358                                                 data_bytes, exponent, val);
 359         }
 360
 361         return 0;
 362 }
 363
 364
 365 void select_transform (int s)
 366 {
 367         char prop_name[PROP_NAME_MAX];
 368         char prop_val[PROP_VALUE_MAX];
 369         int i                   = sensor_info[s].catalog_index;
 370         const char *prefix      = sensor_catalog[i].tag;
 371
 372         sprintf(prop_name, PROP_BASE, prefix, "transform");
 373
 374         if (property_get(prop_name, prop_val, "")) {
 375                 if (!strcmp(prop_val, "ISH")) {
 376                         ALOGI(  "Using Intel Sensor Hub semantics on %s\n",
 377                                 sensor_info[s].friendly_name);
 378
 379                         sensor_info[s].ops.transform = transform_sample_ISH;
 380                         sensor_info[s].ops.finalize = finalize_sample_ISH;
 381                         return;
 382                 }
 383         }
 384
 385         sensor_info[s].ops.transform = transform_sample_default;
 386         sensor_info[s].ops.finalize = finalize_sample_default;
 387 }
 388
 389
 390 float acquire_immediate_value(int s, int c)
 391 {
 392         char sysfs_path[PATH_MAX];
 393         float val;
 394         int ret;
 395         int dev_num = sensor_info[s].dev_num;
 396         int i = sensor_info[s].catalog_index;
 397         const char* raw_path = sensor_catalog[i].channel[c].raw_path;
 398         const char* input_path = sensor_catalog[i].channel[c].input_path;
 399         float scale = sensor_info[s].scale ?
 400                         sensor_info[s].scale : sensor_info[s].channel[c].scale;
 401         float offset = sensor_info[s].offset;
 402         int sensor_type = sensor_catalog[i].type;
 403         float correction;
 404
 405         /* In case correction has been requested using properties, apply it */
 406         correction = sensor_info[s].channel[c].opt_scale;
 407
 408         /* Acquire a sample value for sensor s / channel c through sysfs */
 409
 410         if (input_path[0]) {
 411                 sprintf(sysfs_path, BASE_PATH "%s", dev_num, input_path);
 412                 ret = sysfs_read_float(sysfs_path, &val);
 413
 414                 if (!ret) {
 415                         return val * correction;
 416                 }
 417         };
 418
 419         if (!raw_path[0])
 420                 return 0;
 421
 422         sprintf(sysfs_path, BASE_PATH "%s", dev_num, raw_path);
 423         ret = sysfs_read_float(sysfs_path, &val);
 424
 425         if (ret == -1)
 426                 return 0;
 427
 428         /*
 429         There is no transform ops defined yet for Raw sysfs values
 430         Use this function to perform transformation as well.
 431         */
 432         if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD)
 433                 return  CONVERT_GAUSS_TO_MICROTESLA ((val + offset) * scale) *
 434                         correction;
 435
 436         return (val + offset) * scale * correction;
 437 }