enumeration.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation.
   3  */
   4
   5 #include <dirent.h>
   6 #include <utils/Log.h>
   7 #include <hardware/sensors.h>
   8 #include "enumeration.h"
   9 #include "description.h"
  10 #include "utils.h"
  11 #include "transform.h"
  12
  13 /*
  14  * This table maps syfs entries in scan_elements directories to sensor types,
  15  * and will also be used to determine other sysfs names as well as the iio
  16  * device number associated to a specific sensor.
  17  */
  18
  19 struct sensor_catalog_entry_t sensor_catalog[] = {
  20         DECLARE_SENSOR3("accel",      SENSOR_TYPE_ACCELEROMETER,  "x", "y", "z")
  21         DECLARE_SENSOR3("anglvel",    SENSOR_TYPE_GYROSCOPE,      "x", "y", "z")
  22         DECLARE_SENSOR3("magn",       SENSOR_TYPE_MAGNETIC_FIELD, "x", "y", "z")
  23         DECLARE_SENSOR0("illuminance",SENSOR_TYPE_LIGHT                        )
  24         DECLARE_SENSOR3("incli",      SENSOR_TYPE_ORIENTATION,    "x", "y", "z")
  25         DECLARE_SENSOR4("rot",        SENSOR_TYPE_ROTATION_VECTOR,
  26                                          "quat_x", "quat_y", "quat_z", "quat_w")
  27         DECLARE_SENSOR0("temp",       SENSOR_TYPE_AMBIENT_TEMPERATURE          )
  28 };
  29
  30 #define CATALOG_SIZE    ARRAY_SIZE(sensor_catalog)
  31
  32
  33 /* We equate sensor handles to indices in these tables */
  34
  35 struct sensor_t      sensor_desc[MAX_SENSORS];  /* Android-level descriptors */
  36 struct sensor_info_t sensor_info[MAX_SENSORS];  /* Internal descriptors      */
  37 int sensor_count;                               /* Detected sensors          */
  38
  39
  40 static void add_sensor (int dev_num, int catalog_index, int use_polling)
  41 {
  42         int s;
  43         int sensor_type;
  44         int retval;
  45         char sysfs_path[PATH_MAX];
  46         const char* prefix;
  47         float scale;
  48
  49         if (sensor_count == MAX_SENSORS) {
  50                 ALOGE("Too many sensors!\n");
  51                 return;
  52         }
  53
  54         sensor_type = sensor_catalog[catalog_index].type;
  55
  56         /*
  57          * At this point we could check that the expected sysfs attributes are
  58          * present ; that would enable having multiple catalog entries with the
  59          * same sensor type, accomodating different sets of sysfs attributes.
  60          */
  61
  62         s = sensor_count;
  63
  64         sensor_info[s].dev_num          = dev_num;
  65         sensor_info[s].catalog_index    = catalog_index;
  66
  67         if (use_polling)
  68                 sensor_info[s].num_channels = 0;
  69         else
  70                 sensor_info[s].num_channels =
  71                                 sensor_catalog[catalog_index].num_channels;
  72
  73         prefix = sensor_catalog[catalog_index].tag;
  74
  75         /*
  76          * receiving the illumination sensor calibration inputs from
  77          * the Android properties and setting it within sysfs
  78          */
  79         if (sensor_catalog[catalog_index].type == SENSOR_TYPE_LIGHT) {
  80                 retval = sensor_get_illumincalib(s);
  81                 sprintf(sysfs_path, ILLUMINATION_CALIBPATH, dev_num);
  82                 sysfs_write_int(sysfs_path, retval);
  83         }
  84
  85         /* Read name attribute, if available */
  86         sprintf(sysfs_path, NAME_PATH, dev_num);
  87         sysfs_read_str(sysfs_path, sensor_info[s].internal_name, MAX_NAME_SIZE);
  88
  89         /* See if we have general offsets and scale values for this sensor */
  90
  91         sprintf(sysfs_path, SENSOR_OFFSET_PATH, dev_num, prefix);
  92         sysfs_read_float(sysfs_path, &sensor_info[s].offset);
  93
  94         sprintf(sysfs_path, SENSOR_SCALE_PATH, dev_num, prefix);
  95         if (!sysfs_read_float(sysfs_path, &scale))
  96                 sensor_info[s].scale = scale;
  97         else
  98                 sensor_info[s].scale = 1;
  99
 100         /* Initialize Android-visible descriptor */
 101         sensor_desc[s].name             = sensor_get_name(s);
 102         sensor_desc[s].vendor           = sensor_get_vendor(s);
 103         sensor_desc[s].version          = sensor_get_version(s);
 104         sensor_desc[s].handle           = s;
 105         sensor_desc[s].type             = sensor_type;
 106         sensor_desc[s].maxRange         = sensor_get_max_range(s);
 107         sensor_desc[s].resolution       = sensor_get_resolution(s);
 108         sensor_desc[s].power            = sensor_get_power(s);
 109
 110         if (sensor_info[s].internal_name[0] == '\0') {
 111                 /*
 112                  * In case the kernel-mode driver doesn't expose a name for
 113                  * the iio device, use (null)-dev%d as the trigger name...
 114                  * This can be considered a kernel-mode iio driver bug.
 115                  */
 116                 ALOGW("Using null trigger on sensor %d (dev %d)\n", s, dev_num);
 117                 strcpy(sensor_info[s].internal_name, "(null)");
 118         }
 119
 120         /* Select one of the available sensor sample processing styles */
 121         select_transform(s);
 122
 123         sensor_count++;
 124 }
 125
 126
 127 static void discover_poll_sensors (int dev_num, char map[CATALOG_SIZE])
 128 {
 129         char base_dir[PATH_MAX];
 130         DIR *dir;
 131         char sysfs_dir[PATH_MAX];
 132         struct sensor *sensor;
 133         struct dirent *d;
 134         unsigned int i;
 135         int c;
 136
 137         memset(map, 0, CATALOG_SIZE);
 138
 139         snprintf(base_dir, sizeof(base_dir), BASE_PATH, dev_num);
 140
 141         dir = opendir(base_dir);
 142         if (!dir) {
 143                return;
 144         }
 145
 146         /* Enumerate entries in this iio device's base folder */
 147
 148         while ((d = readdir(dir))) {
 149                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 150                         continue;
 151
 152                 /* If the name matches a catalog entry, flag it */
 153                 for (i = 0; i<CATALOG_SIZE; i++)
 154                         for (c=0; c<sensor_catalog[i].num_channels; c++)
 155                                 if (!strcmp(d->d_name,
 156                                     sensor_catalog[i].channel[c].raw_path) ||
 157                                     !strcmp(d->d_name,
 158                                     sensor_catalog[i].channel[c].input_path)) {
 159                                 map[i] = 1;
 160                                 break;
 161                         }
 162         }
 163
 164         closedir(dir);
 165 }
 166
 167
 168 static void discover_trig_sensors (int dev_num, char map[CATALOG_SIZE])
 169 {
 170         char scan_elem_dir[PATH_MAX];
 171         DIR *dir;
 172         char sysfs_dir[PATH_MAX];
 173         struct sensor *sensor;
 174         struct dirent *d;
 175         unsigned int i;
 176
 177         memset(map, 0, CATALOG_SIZE);
 178
 179         /* Enumerate entries in this iio device's scan_elements folder */
 180
 181         snprintf(scan_elem_dir, sizeof(scan_elem_dir), CHANNEL_PATH, dev_num);
 182
 183         dir = opendir(scan_elem_dir);
 184         if (!dir) {
 185                return;
 186         }
 187
 188         while ((d = readdir(dir))) {
 189                 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 190                         continue;
 191
 192                 /* Compare en entry to known ones and create matching sensors */
 193
 194                 for (i = 0; i<CATALOG_SIZE; i++)
 195                         if (!strcmp(d->d_name,
 196                                     sensor_catalog[i].channel[0].en_path)) {
 197                                 map[i] = 1;
 198                                 break;
 199                         }
 200         }
 201
 202         closedir(dir);
 203 }
 204
 205
 206 static void orientation_sensor_check(void)
 207 {
 208         /*
 209          * If we have accel + gyro + magn but no rotation vector sensor,
 210          * SensorService replaces the HAL provided orientation sensor by the
 211          * AOSP version... provided we report one. So initialize a virtual
 212          * orientation sensor with zero values, which will get replaced. See:
 213          * frameworks/native/services/sensorservice/SensorService.cpp, looking
 214          * for SENSOR_TYPE_ROTATION_VECTOR; that code should presumably fall
 215          * back to mUserSensorList.add instead of replaceAt, but accommodate it.
 216          */
 217
 218         int i;
 219         int has_acc = 0;
 220         int has_gyr = 0;
 221         int has_mag = 0;
 222         int has_rot = 0;
 223         int has_ori = 0;
 224
 225         for (i=0; i<sensor_count; i++)
 226                 switch (sensor_catalog[sensor_info[i].catalog_index].type) {
 227                         case SENSOR_TYPE_ACCELEROMETER:
 228                                 has_acc = 1;
 229                                 break;
 230                         case SENSOR_TYPE_GYROSCOPE:
 231                                 has_gyr = 1;
 232                                 break;
 233                         case SENSOR_TYPE_MAGNETIC_FIELD:
 234                                 has_mag = 1;
 235                                 break;
 236                         case SENSOR_TYPE_ORIENTATION:
 237                                 has_ori = 1;
 238                                 break;
 239                         case SENSOR_TYPE_ROTATION_VECTOR:
 240                                 has_rot = 1;
 241                                 break;
 242                 }
 243
 244         if (has_acc && has_gyr && has_mag && !has_rot && !has_ori)
 245                 for (i=0; i<CATALOG_SIZE; i++)
 246                         if (sensor_catalog[i].type == SENSOR_TYPE_ORIENTATION) {
 247                                 ALOGI("Adding placeholder orientation sensor");
 248                                 add_sensor(0, i, 1);
 249                                 break;
 250                         }
 251 }
 252
 253
 254 void enumerate_sensors (void)
 255 {
 256         /*
 257          * Discover supported sensors and allocate control structures for them.
 258          * Multiple sensors can potentially rely on a single iio device (each
 259          * using their own channels). We can't have multiple sensors of the same
 260          * type on the same device. In case of detection as both a poll-mode
 261          * and trigger-based sensor, use the trigger usage mode.
 262          */
 263         char poll_sensors[CATALOG_SIZE];
 264         char trig_sensors[CATALOG_SIZE];
 265         int dev_num;
 266         unsigned int i;
 267
 268         for (dev_num=0; dev_num<MAX_DEVICES; dev_num++) {
 269                 discover_poll_sensors(dev_num, poll_sensors);
 270                 discover_trig_sensors(dev_num, trig_sensors);
 271
 272                 for (i=0; i<CATALOG_SIZE; i++)
 273                         if (trig_sensors[i])
 274                                 add_sensor(dev_num, i, 0);
 275                         else
 276                                 if (poll_sensors[i])
 277                                         add_sensor(dev_num, i, 1);
 278         }
 279
 280         ALOGI("Discovered %d sensors\n", sensor_count);
 281
 282         /* Make sure Android fall backs to its own orientation sensor */
 283         orientation_sensor_check();
 284 }
 285
 286
 287 void delete_enumeration_data (void)
 288 {
 289         /* Reset sensor count */
 290         sensor_count = 0;
 291 }
 292
 293
 294 int get_sensors_list(   struct sensors_module_t* module,
 295                         struct sensor_t const** list)
 296 {
 297         *list = sensor_desc;
 298         return sensor_count;
 299 }
 300