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