enumeration.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation.
   3  */
   4
   5 #include <ctype.h>
   6 #include <dirent.h>
   7 #include <stdlib.h>
   8 #include <utils/Log.h>
   9 #include <hardware/sensors.h>
  10 #include "enumeration.h"
  11 #include "description.h"
  12 #include "utils.h"
  13 #include "transform.h"
  14 #include "description.h"
  15 #include "control.h"
  16 #include "calibration.h"
  17
  18 /*
  19  * This table maps syfs entries in scan_elements directories to sensor types,
  20  * and will also be used to determine other sysfs names as well as the iio
  21  * device number associated to a specific sensor.
  22  */
  23
  24  /*
  25   * We duplicate entries for the uncalibrated types after their respective base
  26   * sensor. This is because all sensor entries must have an associated catalog entry
  27   * and also because when only the uncal sensor is active it needs to take it's data
  28   * from the same iio device as the base one.
  29   */
  30
  31 struct sensor_catalog_entry_t sensor_catalog[] = {
  32         DECLARE_SENSOR3("accel",      SENSOR_TYPE_ACCELEROMETER,  "x", "y", "z")
  33         DECLARE_SENSOR3("anglvel",    SENSOR_TYPE_GYROSCOPE,      "x", "y", "z")
  34         DECLARE_SENSOR3("magn",       SENSOR_TYPE_MAGNETIC_FIELD, "x", "y", "z")
  35         DECLARE_SENSOR1("intensity",  SENSOR_TYPE_LIGHT,          "both"       )
  36         DECLARE_SENSOR0("illuminance",SENSOR_TYPE_LIGHT                        )
  37         DECLARE_SENSOR3("incli",      SENSOR_TYPE_ORIENTATION,    "x", "y", "z")
  38         DECLARE_SENSOR4("rot",        SENSOR_TYPE_ROTATION_VECTOR,
  39                                          "quat_x", "quat_y", "quat_z", "quat_w")
  40         DECLARE_SENSOR0("temp",       SENSOR_TYPE_AMBIENT_TEMPERATURE          )
  41         DECLARE_SENSOR0("proximity",  SENSOR_TYPE_PROXIMITY                    )
  42         DECLARE_SENSOR3("anglvel",      SENSOR_TYPE_GYROSCOPE_UNCALIBRATED, "x", "y", "z")
  43 };
  44
  45 #define CATALOG_SIZE    ARRAY_SIZE(sensor_catalog)
  46
  47 /* ACPI PLD (physical location of device) definitions, as used with sensors */
  48
  49 #define PANEL_FRONT     4
  50 #define PANEL_BACK      5
  51
  52 /* We equate sensor handles to indices in these tables */
  53
  54 struct sensor_t      sensor_desc[MAX_SENSORS];  /* Android-level descriptors */
  55 struct sensor_info_t sensor_info[MAX_SENSORS];  /* Internal descriptors      */
  56 int sensor_count;                               /* Detected sensors          */
  57
  58
  59 static void setup_properties_from_pld(int s, int panel, int rotation,
  60                                       int num_channels)
  61 {
  62         /*
  63          * Generate suitable order and opt_scale directives from the PLD panel
  64          * and rotation codes we got. This can later be superseded by the usual
  65          * properties if necessary. Eventually we'll need to replace these
  66          * mechanisms by a less convoluted one, such as a 3x3 placement matrix.
  67          */
  68
  69         int x = 1;
  70         int y = 1;
  71         int z = 1;
  72         int xy_swap = 0;
  73         int angle = rotation * 45;
  74
  75         /* Only deal with 3 axis chips for now */
  76         if (num_channels < 3)
  77                 return;
  78
  79         if (panel == PANEL_BACK) {
  80                 /* Chip placed on the back panel ; negate x and z */
  81                 x = -x;
  82                 z = -z;
  83         }
  84
  85         switch (angle) {
  86                 case 90: /* 90° clockwise: negate y then swap x,y */
  87                         xy_swap = 1;
  88                         y = -y;
  89                         break;
  90
  91                 case 180: /* Upside down: negate x and y */
  92                         x = -x;
  93                         y = -y;
  94                         break;
  95
  96                 case 270: /* 90° counter clockwise: negate x then swap x,y */
  97                         x = -x;
  98                         xy_swap = 1;
  99                         break;
 100         }
 101
 102         if (xy_swap) {
 103                 sensor_info[s].order[0] = 1;
 104                 sensor_info[s].order[1] = 0;
 105                 sensor_info[s].order[2] = 2;
 106                 sensor_info[s].quirks |= QUIRK_FIELD_ORDERING;
 107         }
 108
 109         sensor_info[s].channel[0].opt_scale = x;
 110         sensor_info[s].channel[1].opt_scale = y;
 111         sensor_info[s].channel[2].opt_scale = z;
 112 }
 113
 114
 115 static int is_valid_pld (int panel, int rotation)
 116 {
 117         if (panel != PANEL_FRONT && panel != PANEL_BACK) {
 118                 ALOGW("Unhandled PLD panel spec: %d\n", panel);
 119                 return 0;
 120         }
 121
 122         /* Only deal with 90° rotations for now */
 123         if (rotation < 0 || rotation > 7 || (rotation & 1)) {
 124                 ALOGW("Unhandled PLD rotation spec: %d\n", rotation);
 125                 return 0;
 126         }
 127
 128         return 1;
 129 }
 130
 131
 132 static int read_pld_from_properties (int s, int* panel, int* rotation)
 133 {
 134         int p, r;
 135
 136         if (sensor_get_prop(s, "panel", &p))
 137                 return -1;
 138
 139         if (sensor_get_prop(s, "rotation", &r))
 140                 return -1;
 141
 142         if (!is_valid_pld(p, r))
 143                 return -1;
 144
 145         *panel = p;
 146         *rotation = r;
 147
 148         ALOGI("S%d PLD from properties: panel=%d, rotation=%d\n", s, p, r);
 149
 150         return 0;
 151 }
 152
 153
 154 static int read_pld_from_sysfs (int s, int dev_num, int* panel, int* rotation)
 155 {
 156         char sysfs_path[PATH_MAX];
 157         int p,r;
 158
 159         sprintf(sysfs_path, BASE_PATH "../firmware_node/pld/panel", dev_num);
 160
 161         if (sysfs_read_int(sysfs_path, &p))
 162                 return -1;
 163
 164         sprintf(sysfs_path, BASE_PATH "../firmware_node/pld/rotation", dev_num);
 165
 166         if (sysfs_read_int(sysfs_path, &r))
 167                 return -1;
 168
 169         if (!is_valid_pld(p, r))
 170                 return -1;
 171
 172         *panel = p;
 173         *rotation = r;
 174
 175         ALOGI("S%d PLD from sysfs: panel=%d, rotation=%d\n", s, p, r);
 176
 177         return 0;
 178 }
 179
 180
 181 static void decode_placement_information (int dev_num, int num_channels, int s)
 182 {
 183         /*
 184          * See if we have optional "physical location of device" ACPI tags.
 185          * We're only interested in panel and rotation specifiers. Use the
 186          * .panel and .rotation properties in priority, and the actual ACPI
 187          * values as a second source.
 188          */
 189
 190         int panel;
 191         int rotation;
 192
 193         if (read_pld_from_properties(s, &panel, &rotation) &&
 194                 read_pld_from_sysfs(s, dev_num, &panel, &rotation))
 195                         return; /* No PLD data available */
 196
 197         /* Map that to field ordering and scaling mechanisms */
 198         setup_properties_from_pld(s, panel, rotation, num_channels);
 199 }
 200
 201
 202 static void add_sensor (int dev_num, int catalog_index, int use_polling)
 203 {
 204         int s;
 205         int sensor_type;
 206         int retval;
 207         char sysfs_path[PATH_MAX];
 208         const char* prefix;
 209         float scale;
 210         int c;
 211         float opt_scale;
 212         const char* ch_name;
 213         int num_channels;
 214         char suffix[MAX_NAME_SIZE + 8];
 215
 216         if (sensor_count == MAX_SENSORS) {
 217                 ALOGE("Too many sensors!\n");
 218                 return;
 219         }
 220
 221         sensor_type = sensor_catalog[catalog_index].type;
 222
 223         /*
 224          * At this point we could check that the expected sysfs attributes are
 225          * present ; that would enable having multiple catalog entries with the
 226          * same sensor type, accomodating different sets of sysfs attributes.
 227          */
 228
 229         s = sensor_count;
 230
 231         sensor_info[s].dev_num          = dev_num;
 232         sensor_info[s].catalog_index    = catalog_index;
 233
 234         num_channels = sensor_catalog[catalog_index].num_channels;
 235
 236         if (use_polling)
 237                 sensor_info[s].num_channels = 0;
 238         else
 239                 sensor_info[s].num_channels = num_channels;
 240
 241         prefix = sensor_catalog[catalog_index].tag;
 242
 243         /*
 244          * receiving the illumination sensor calibration inputs from
 245          * the Android properties and setting it within sysfs
 246          */
 247         if (sensor_catalog[catalog_index].type == SENSOR_TYPE_LIGHT) {
 248                 retval = sensor_get_illumincalib(s);
 249                 if (retval > 0) {
 250                         sprintf(sysfs_path, ILLUMINATION_CALIBPATH, dev_num);
 251                         sysfs_write_int(sysfs_path, retval);
 252                 }
 253         }
 254
 255         /* Read name attribute, if available */
 256         sprintf(sysfs_path, NAME_PATH, dev_num);
 257         sysfs_read_str(sysfs_path, sensor_info[s].internal_name, MAX_NAME_SIZE);
 258
 259         /* See if we have general offsets and scale values for this sensor */
 260
 261         sprintf(sysfs_path, SENSOR_OFFSET_PATH, dev_num, prefix);
 262         sysfs_read_float(sysfs_path, &sensor_info[s].offset);
 263
 264         sprintf(sysfs_path, SENSOR_SCALE_PATH, dev_num, prefix);
 265         if (!sysfs_read_float(sysfs_path, &scale)) {
 266                 sensor_info[s].scale = scale;
 267                 ALOGI("Scale path:%s scale:%f dev_num:%d\n",
 268                                         sysfs_path, scale, dev_num);
 269         } else {
 270                 sensor_info[s].scale = 1;
 271
 272                 /* Read channel specific scale if any*/
 273                 for (c = 0; c < num_channels; c++)
 274                 {
 275                         sprintf(sysfs_path, BASE_PATH "%s", dev_num,
 276                            sensor_catalog[catalog_index].channel[c].scale_path);
 277
 278                         if (!sysfs_read_float(sysfs_path, &scale)) {
 279                                 sensor_info[s].channel[c].scale = scale;
 280                                 sensor_info[s].scale = 0;
 281
 282                                 ALOGI(  "Scale path:%s "
 283                                         "channel scale:%f dev_num:%d\n",
 284                                         sysfs_path, scale, dev_num);
 285                         }
 286                 }
 287         }
 288
 289         /* Set default scaling - if num_channels is zero, we have one channel */
 290
 291         sensor_info[s].channel[0].opt_scale = 1;
 292
 293         for (c = 1; c < num_channels; c++)
 294                 sensor_info[s].channel[c].opt_scale = 1;
 295
 296         /* Read ACPI _PLD attributes for this sensor, if there are any */
 297         decode_placement_information(dev_num, num_channels, s);
 298
 299         /*
 300          * See if we have optional correction scaling factors for each of the
 301          * channels of this sensor. These would be expressed using properties
 302          * like iio.accel.y.opt_scale = -1. In case of a single channel we also
 303          * support things such as iio.temp.opt_scale = -1. Note that this works
 304          * for all types of sensors, and whatever transform is selected, on top
 305          * of any previous conversions.
 306          */
 307
 308         if (num_channels) {
 309                 for (c = 0; c < num_channels; c++) {
 310                         ch_name = sensor_catalog[catalog_index].channel[c].name;
 311                         sprintf(suffix, "%s.opt_scale", ch_name);
 312                         if (!sensor_get_fl_prop(s, suffix, &opt_scale))
 313                                 sensor_info[s].channel[c].opt_scale = opt_scale;
 314                 }
 315         } else
 316                 if (!sensor_get_fl_prop(s, "opt_scale", &opt_scale))
 317                         sensor_info[s].channel[0].opt_scale = opt_scale;
 318
 319         /* Initialize Android-visible descriptor */
 320         sensor_desc[s].name             = sensor_get_name(s);
 321         sensor_desc[s].vendor           = sensor_get_vendor(s);
 322         sensor_desc[s].version          = sensor_get_version(s);
 323         sensor_desc[s].handle           = s;
 324         sensor_desc[s].type             = sensor_type;
 325         sensor_desc[s].maxRange         = sensor_get_max_range(s);
 326         sensor_desc[s].resolution       = sensor_get_resolution(s);
 327         sensor_desc[s].power            = sensor_get_power(s);
 328         sensor_desc[s].stringType = sensor_get_string_type(s);
 329
 330         /* None of our supported sensors requires a special permission.
 331         *  If this will be the case we should implement a sensor_get_perm
 332         */
 333         sensor_desc[s].requiredPermission = "";
 334         sensor_desc[s].flags = sensor_get_flags(s);
 335         sensor_desc[s].maxDelay = sensor_get_max_delay(s);
 336
 337         if (sensor_info[s].internal_name[0] == '\0') {
 338                 /*
 339                  * In case the kernel-mode driver doesn't expose a name for
 340                  * the iio device, use (null)-dev%d as the trigger name...
 341                  * This can be considered a kernel-mode iio driver bug.
 342                  */
 343                 ALOGW("Using null trigger on sensor %d (dev %d)\n", s, dev_num);
 344                 strcpy(sensor_info[s].internal_name, "(null)");
 345         }
 346
 347         if (sensor_type == SENSOR_TYPE_GYROSCOPE ||
 348                 sensor_type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED) {
 349                 struct gyro_cal* calibration_data = calloc(1, sizeof(struct gyro_cal));
 350                 sensor_info[s].cal_data = calibration_data;
 351         }
 352
 353         if (sensor_type == SENSOR_TYPE_MAGNETIC_FIELD) {
 354                 struct compass_cal* calibration_data = calloc(1, sizeof(struct compass_cal));
 355                 sensor_info[s].cal_data = calibration_data;
 356         }
 357
 358         /* Select one of the available sensor sample processing styles */
 359         select_transform(s);
 360
 361         /* Initialize fields related to sysfs reads offloading */
 362         sensor_info[s].thread_data_fd[0]  = -1;
 363         sensor_info[s].thread_data_fd[1]  = -1;
 364         sensor_info[s].acquisition_thread = -1;
 365
 366         /* Check if we have a special ordering property on this sensor */
 367         if (sensor_get_order(s, sensor_info[s].order))
 368                 sensor_info[s].quirks |= QUIRK_FIELD_ORDERING;
 369
 370         sensor_count++;
 371 }
 372
 373
 374 static void discover_poll_sensors (int dev_num, char map[CATALOG_SIZE])
 375 {
 376         char base_dir[PATH_MAX];
 377         DIR *dir;
 378         struct dirent *d;
 379         unsigned int i;
 380         int c;
 381
 382         memset(map, 0, CATALOG_SIZE);
 383
 384         snprintf(base_dir, sizeof(base_dir), BASE_PATH, dev_num);
 385
 386         dir = opendir(base_dir);
 387         if (!dir) {
 388                 return;
 389         }
 390
 391         /* Enumerate entries in this iio device's base folder */
 392
 393         while ((d = readdir(dir))) {
 394                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 395                         continue;
 396
 397                 /* If the name matches a catalog entry, flag it */
 398                 for (i = 0; i<CATALOG_SIZE; i++) {
 399                 /* This will be added separately later */
 400                 if (sensor_catalog[i].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED)
 401                         continue;
 402                 for (c=0; c<sensor_catalog[i].num_channels; c++)
 403                         if (!strcmp(d->d_name,sensor_catalog[i].channel[c].raw_path) ||
 404                                 !strcmp(d->d_name, sensor_catalog[i].channel[c].input_path)) {
 405                                         map[i] = 1;
 406                                         break;
 407                         }
 408                 }
 409         }
 410
 411         closedir(dir);
 412 }
 413
 414
 415 static void discover_trig_sensors (int dev_num, char map[CATALOG_SIZE])
 416 {
 417         char scan_elem_dir[PATH_MAX];
 418         DIR *dir;
 419         struct dirent *d;
 420         unsigned int i;
 421
 422         memset(map, 0, CATALOG_SIZE);
 423
 424         /* Enumerate entries in this iio device's scan_elements folder */
 425
 426         snprintf(scan_elem_dir, sizeof(scan_elem_dir), CHANNEL_PATH, dev_num);
 427
 428         dir = opendir(scan_elem_dir);
 429         if (!dir) {
 430                 return;
 431         }
 432
 433         while ((d = readdir(dir))) {
 434                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 435                         continue;
 436
 437                 /* Compare en entry to known ones and create matching sensors */
 438
 439                 for (i = 0; i<CATALOG_SIZE; i++) {
 440                         if (sensor_catalog[i].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED)
 441                                 continue;
 442                         if (!strcmp(d->d_name,
 443                                         sensor_catalog[i].channel[0].en_path)) {
 444                                         map[i] = 1;
 445                                         break;
 446                         }
 447                 }
 448         }
 449
 450         closedir(dir);
 451 }
 452
 453
 454 static void orientation_sensor_check(void)
 455 {
 456         /*
 457          * If we have accel + gyro + magn but no rotation vector sensor,
 458          * SensorService replaces the HAL provided orientation sensor by the
 459          * AOSP version... provided we report one. So initialize a virtual
 460          * orientation sensor with zero values, which will get replaced. See:
 461          * frameworks/native/services/sensorservice/SensorService.cpp, looking
 462          * for SENSOR_TYPE_ROTATION_VECTOR; that code should presumably fall
 463          * back to mUserSensorList.add instead of replaceAt, but accommodate it.
 464          */
 465
 466         int i;
 467         int has_acc = 0;
 468         int has_gyr = 0;
 469         int has_mag = 0;
 470         int has_rot = 0;
 471         int has_ori = 0;
 472         int catalog_size = CATALOG_SIZE;
 473
 474         for (i=0; i<sensor_count; i++)
 475                 switch (sensor_catalog[sensor_info[i].catalog_index].type) {
 476                         case SENSOR_TYPE_ACCELEROMETER:
 477                                 has_acc = 1;
 478                                 break;
 479                         case SENSOR_TYPE_GYROSCOPE:
 480                                 has_gyr = 1;
 481                                 break;
 482                         case SENSOR_TYPE_MAGNETIC_FIELD:
 483                                 has_mag = 1;
 484                                 break;
 485                         case SENSOR_TYPE_ORIENTATION:
 486                                 has_ori = 1;
 487                                 break;
 488                         case SENSOR_TYPE_ROTATION_VECTOR:
 489                                 has_rot = 1;
 490                                 break;
 491                 }
 492
 493         if (has_acc && has_gyr && has_mag && !has_rot && !has_ori)
 494                 for (i=0; i<catalog_size; i++)
 495                         if (sensor_catalog[i].type == SENSOR_TYPE_ORIENTATION) {
 496                                 ALOGI("Adding placeholder orientation sensor");
 497                                 add_sensor(0, i, 1);
 498                                 break;
 499                         }
 500 }
 501
 502 static void uncalibrated_gyro_check (void)
 503 {
 504         unsigned int has_gyr = 0;
 505         unsigned int dev_num;
 506         int i, c;
 507         unsigned int is_poll_sensor;
 508
 509         int cal_idx = 0;
 510         int uncal_idx = 0;
 511
 512         /* Checking to see if we have a gyroscope - we can only have uncal if we have the base sensor */
 513         for (i=0; i < sensor_count; i++)
 514                 if(sensor_catalog[sensor_info[i].catalog_index].type == SENSOR_TYPE_GYROSCOPE)
 515                 {
 516                         has_gyr=1;
 517                         dev_num = sensor_info[i].dev_num;
 518                         is_poll_sensor = !sensor_info[i].num_channels;
 519                         cal_idx = i;
 520                         break;
 521                 }
 522
 523         /*
 524          * If we have a gyro we can add the uncalibrated sensor of the same type and
 525          * on the same dev_num. We will save indexes for easy finding and also save the
 526          * channel specific information.
 527          */
 528         if (has_gyr)
 529                 for (i=0; i<CATALOG_SIZE; i++)
 530                         if (sensor_catalog[i].type == SENSOR_TYPE_GYROSCOPE_UNCALIBRATED) {
 531                                 add_sensor(dev_num, i, is_poll_sensor);
 532
 533                                 uncal_idx = sensor_count - 1; /* Just added uncalibrated sensor */
 534
 535                                 /* Similar to build_sensor_report_maps */
 536                                 for (c = 0; c < sensor_info[uncal_idx].num_channels; c++)
 537                                 {
 538                                         memcpy( &(sensor_info[uncal_idx].channel[c].type_spec),
 539                                                 &(sensor_info[cal_idx].channel[c].type_spec),
 540                                                 sizeof(sensor_info[uncal_idx].channel[c].type_spec));
 541                                         sensor_info[uncal_idx].channel[c].type_info = sensor_info[cal_idx].channel[c].type_info;
 542                                         sensor_info[uncal_idx].channel[c].offset    = sensor_info[cal_idx].channel[c].offset;
 543                                         sensor_info[uncal_idx].channel[c].size      = sensor_info[cal_idx].channel[c].size;
 544                                 }
 545                                 strncpy(sensor_info[uncal_idx].trigger_name,
 546                                         sensor_info[cal_idx].trigger_name,
 547                                         MAX_NAME_SIZE);
 548                                 sensor_info[uncal_idx].pair_idx = cal_idx;
 549                                 sensor_info[cal_idx].pair_idx = uncal_idx;
 550                                 break;
 551                         }
 552 }
 553
 554 static int is_continuous (int s)
 555 {
 556         /* Is sensor s of the continous trigger type kind? */
 557
 558         int catalog_index = sensor_info[s].catalog_index;
 559         int sensor_type = sensor_catalog[catalog_index].type;
 560
 561         switch (sensor_type) {
 562                 case SENSOR_TYPE_ACCELEROMETER:
 563                 case SENSOR_TYPE_MAGNETIC_FIELD:
 564                 case SENSOR_TYPE_ORIENTATION:
 565                 case SENSOR_TYPE_GYROSCOPE:
 566                 case SENSOR_TYPE_PRESSURE:
 567                 case SENSOR_TYPE_GRAVITY:
 568                 case SENSOR_TYPE_LINEAR_ACCELERATION:
 569                 case SENSOR_TYPE_ROTATION_VECTOR:
 570                 case SENSOR_TYPE_MAGNETIC_FIELD_UNCALIBRATED:
 571                 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
 572                 case SENSOR_TYPE_GEOMAGNETIC_ROTATION_VECTOR:
 573                         return 1;
 574
 575                 default:
 576                         return 0;
 577         }
 578 }
 579
 580
 581 static void propose_new_trigger (int s, char trigger_name[MAX_NAME_SIZE],
 582                                  int sensor_name_len)
 583 {
 584         /*
 585          * A new trigger has been enumerated for this sensor. Check if it makes
 586          * sense to use it over the currently selected one, and select it if it
 587          * is so. The format is something like sensor_name-dev0.
 588          */
 589
 590         const char *suffix = trigger_name + sensor_name_len + 1;
 591
 592         /* dev is the default, and lowest priority; no need to update */
 593         if (!memcmp(suffix, "dev", 3))
 594                 return;
 595
 596         /*
 597          * Anything else is higher priority. However if we already found an
 598          * any-motion trigger, don't select anything else.
 599          */
 600
 601         if (!memcmp(sensor_info[s].trigger_name + sensor_name_len + 1,
 602                     "any-motion-", 11))
 603                 return;
 604
 605         /*
 606          * If we're switching to an any-motion trigger, force the sensor to
 607          * automatic intermediate event generation mode, at least if it is of a
 608          * continuously firing sensor type.
 609          */
 610
 611         if (!memcmp(suffix, "any-motion-", 11) && is_continuous(s))
 612                 sensor_info[s].quirks |= QUIRK_TERSE_DRIVER;
 613
 614         /* Update the trigger name to use for this sensor */
 615         strcpy(sensor_info[s].trigger_name, trigger_name);
 616 }
 617
 618
 619 static void update_sensor_matching_trigger_name (char name[MAX_NAME_SIZE])
 620 {
 621         /*
 622          * Check if we have a sensor matching the specified trigger name,
 623          * which should then begin with the sensor name, and end with a number
 624          * equal to the iio device number the sensor is associated to. If so,
 625          * update the string we're going to write to trigger/current_trigger
 626          * when enabling this sensor.
 627          */
 628
 629         int s;
 630         int dev_num;
 631         int len;
 632         char* cursor;
 633         int sensor_name_len;
 634
 635         /*
 636          * First determine the iio device number this trigger refers to. We
 637          * expect the last few characters (typically one) of the trigger name
 638          * to be this number, so perform a few checks.
 639          */
 640         len = strnlen(name, MAX_NAME_SIZE);
 641
 642         if (len < 2)
 643                 return;
 644
 645         cursor = name + len - 1;
 646
 647         if (!isdigit(*cursor))
 648                 return;
 649
 650         while (len && isdigit(*cursor)) {
 651                 len--;
 652                 cursor--;
 653         }
 654
 655         dev_num = atoi(cursor+1);
 656
 657         /* See if that matches a sensor */
 658         for (s=0; s<sensor_count; s++)
 659                 if (sensor_info[s].dev_num == dev_num) {
 660
 661                         sensor_name_len = strlen(sensor_info[s].internal_name);
 662
 663                         if (!strncmp(name,
 664                                      sensor_info[s].internal_name,
 665                                      sensor_name_len))
 666                                 /* Switch to new trigger if appropriate */
 667                                 propose_new_trigger(s, name, sensor_name_len);
 668                 }
 669 }
 670
 671
 672 static void setup_trigger_names (void)
 673 {
 674         char filename[PATH_MAX];
 675         char buf[MAX_NAME_SIZE];
 676         int len;
 677         int s;
 678         int trigger;
 679         int ret;
 680
 681         /* By default, use the name-dev convention that most drivers use */
 682         for (s=0; s<sensor_count; s++)
 683                 snprintf(sensor_info[s].trigger_name, MAX_NAME_SIZE, "%s-dev%d",
 684                         sensor_info[s].internal_name, sensor_info[s].dev_num);
 685
 686         /* Now have a look to /sys/bus/iio/devices/triggerX entries */
 687
 688         for (trigger=0; trigger<MAX_TRIGGERS; trigger++) {
 689
 690                 snprintf(filename, sizeof(filename), TRIGGER_FILE_PATH,trigger);
 691
 692                 ret = sysfs_read_str(filename, buf, sizeof(buf));
 693
 694                 if (ret < 0)
 695                         break;
 696
 697                 update_sensor_matching_trigger_name(buf);
 698         }
 699
 700         for (s=0; s<sensor_count; s++)
 701                 if (sensor_info[s].num_channels) {
 702                         ALOGI(  "Sensor %d (%s) using iio trigger %s\n", s,
 703                                 sensor_info[s].friendly_name,
 704                                 sensor_info[s].trigger_name);
 705                 }
 706 }
 707
 708
 709 void enumerate_sensors (void)
 710 {
 711         /*
 712          * Discover supported sensors and allocate control structures for them.
 713          * Multiple sensors can potentially rely on a single iio device (each
 714          * using their own channels). We can't have multiple sensors of the same
 715          * type on the same device. In case of detection as both a poll-mode
 716          * and trigger-based sensor, use the trigger usage mode.
 717          */
 718         char poll_sensors[CATALOG_SIZE];
 719         char trig_sensors[CATALOG_SIZE];
 720         int dev_num;
 721         unsigned int i;
 722         int trig_found;
 723
 724         for (dev_num=0; dev_num<MAX_DEVICES; dev_num++) {
 725                 trig_found = 0;
 726
 727                 discover_poll_sensors(dev_num, poll_sensors);
 728                 discover_trig_sensors(dev_num, trig_sensors);
 729
 730                 for (i=0; i<CATALOG_SIZE; i++)
 731                         if (trig_sensors[i]) {
 732                                 add_sensor(dev_num, i, 0);
 733                                 trig_found = 1;
 734                         }
 735                         else
 736                                 if (poll_sensors[i])
 737                                         add_sensor(dev_num, i, 1);
 738
 739                 if (trig_found) {
 740                         build_sensor_report_maps(dev_num);
 741                 }
 742         }
 743
 744         ALOGI("Discovered %d sensors\n", sensor_count);
 745
 746         /* Set up default - as well as custom - trigger names */
 747         setup_trigger_names();
 748
 749         /* Make sure Android fall backs to its own orientation sensor */
 750         orientation_sensor_check();
 751
 752         /* Create the uncalibrated counterpart to the compensated gyroscope;
 753          * This is is a new sensor type in Android 4.4 */
 754         uncalibrated_gyro_check();
 755 }
 756
 757
 758 void delete_enumeration_data (void)
 759 {
 760
 761         int i;
 762         for (i = 0; i < sensor_count; i++)
 763         switch (sensor_catalog[sensor_info[i].catalog_index].type) {
 764                 case SENSOR_TYPE_MAGNETIC_FIELD:
 765                 case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
 766                 case SENSOR_TYPE_GYROSCOPE:
 767                         if (sensor_info[i].cal_data != NULL) {
 768                                 free(sensor_info[i].cal_data);
 769                                 sensor_info[i].cal_data = NULL;
 770                                 sensor_info[i].cal_level = 0;
 771                         }
 772                         break;
 773                 default:
 774                         break;
 775         }
 776         /* Reset sensor count */
 777         sensor_count = 0;
 778 }
 779
 780
 781 int get_sensors_list(   struct sensors_module_t* module,
 782                         struct sensor_t const** list)
 783 {
 784         *list = sensor_desc;
 785         return sensor_count;
 786 }
 787