tools/iio/iio_utils.c

   1 /* IIO - useful set of util functionality
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  */
   9
  10 #include <string.h>
  11 #include <stdlib.h>
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <dirent.h>
  15 #include <errno.h>
  16 #include <ctype.h>
  17 #include "iio_utils.h"
  18
  19 const char *iio_dir = "/sys/bus/iio/devices/";
  20
  21 /**
  22  * iioutils_break_up_name() - extract generic name from full channel name
  23  * @full_name: the full channel name
  24  * @generic_name: the output generic channel name
  25  **/
  26 int iioutils_break_up_name(const char *full_name,
  27                                   char **generic_name)
  28 {
  29         char *current;
  30         char *w, *r;
  31         char *working;
  32
  33         current = strdup(full_name);
  34         working = strtok(current, "_\0");
  35         w = working;
  36         r = working;
  37
  38         while (*r != '\0') {
  39                 if (!isdigit(*r)) {
  40                         *w = *r;
  41                         w++;
  42                 }
  43                 r++;
  44         }
  45         *w = '\0';
  46         *generic_name = strdup(working);
  47         free(current);
  48
  49         return 0;
  50 }
  51
  52 /**
  53  * iioutils_get_type() - find and process _type attribute data
  54  * @is_signed: output whether channel is signed
  55  * @bytes: output how many bytes the channel storage occupies
  56  * @mask: output a bit mask for the raw data
  57  * @be: big endian
  58  * @device_dir: the iio device directory
  59  * @name: the channel name
  60  * @generic_name: the channel type name
  61  **/
  62 int iioutils_get_type(unsigned *is_signed,
  63                              unsigned *bytes,
  64                              unsigned *bits_used,
  65                              unsigned *shift,
  66                              uint64_t *mask,
  67                              unsigned *be,
  68                              const char *device_dir,
  69                              const char *name,
  70                              const char *generic_name)
  71 {
  72         FILE *sysfsfp;
  73         int ret;
  74         DIR *dp;
  75         char *scan_el_dir, *builtname, *builtname_generic, *filename = 0;
  76         char signchar, endianchar;
  77         unsigned padint;
  78         const struct dirent *ent;
  79
  80         ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
  81         if (ret < 0) {
  82                 ret = -ENOMEM;
  83                 goto error_ret;
  84         }
  85         ret = asprintf(&builtname, FORMAT_TYPE_FILE, name);
  86         if (ret < 0) {
  87                 ret = -ENOMEM;
  88                 goto error_free_scan_el_dir;
  89         }
  90         ret = asprintf(&builtname_generic, FORMAT_TYPE_FILE, generic_name);
  91         if (ret < 0) {
  92                 ret = -ENOMEM;
  93                 goto error_free_builtname;
  94         }
  95
  96         dp = opendir(scan_el_dir);
  97         if (dp == NULL) {
  98                 ret = -errno;
  99                 goto error_free_builtname_generic;
 100         }
 101         while (ent = readdir(dp), ent != NULL)
 102                 /*
 103                  * Do we allow devices to override a generic name with
 104                  * a specific one?
 105                  */
 106                 if ((strcmp(builtname, ent->d_name) == 0) ||
 107                     (strcmp(builtname_generic, ent->d_name) == 0)) {
 108                         ret = asprintf(&filename,
 109                                        "%s/%s", scan_el_dir, ent->d_name);
 110                         if (ret < 0) {
 111                                 ret = -ENOMEM;
 112                                 goto error_closedir;
 113                         }
 114                         sysfsfp = fopen(filename, "r");
 115                         if (sysfsfp == NULL) {
 116                                 printf("failed to open %s\n", filename);
 117                                 ret = -errno;
 118                                 goto error_free_filename;
 119                         }
 120
 121                         ret = fscanf(sysfsfp,
 122                                      "%ce:%c%u/%u>>%u",
 123                                      &endianchar,
 124                                      &signchar,
 125                                      bits_used,
 126                                      &padint, shift);
 127                         if (ret < 0) {
 128                                 printf("failed to pass scan type description\n");
 129                                 ret = -errno;
 130                                 goto error_close_sysfsfp;
 131                         }
 132                         *be = (endianchar == 'b');
 133                         *bytes = padint / 8;
 134                         if (*bits_used == 64)
 135                                 *mask = ~0;
 136                         else
 137                                 *mask = (1 << *bits_used) - 1;
 138                         if (signchar == 's')
 139                                 *is_signed = 1;
 140                         else
 141                                 *is_signed = 0;
 142                         fclose(sysfsfp);
 143                         free(filename);
 144
 145                         filename = 0;
 146                         sysfsfp = 0;
 147                 }
 148 error_close_sysfsfp:
 149         if (sysfsfp)
 150                 fclose(sysfsfp);
 151 error_free_filename:
 152         if (filename)
 153                 free(filename);
 154 error_closedir:
 155         closedir(dp);
 156 error_free_builtname_generic:
 157         free(builtname_generic);
 158 error_free_builtname:
 159         free(builtname);
 160 error_free_scan_el_dir:
 161         free(scan_el_dir);
 162 error_ret:
 163         return ret;
 164 }
 165
 166 int iioutils_get_param_float(float *output,
 167                                     const char *param_name,
 168                                     const char *device_dir,
 169                                     const char *name,
 170                                     const char *generic_name)
 171 {
 172         FILE *sysfsfp;
 173         int ret;
 174         DIR *dp;
 175         char *builtname, *builtname_generic;
 176         char *filename = NULL;
 177         const struct dirent *ent;
 178
 179         ret = asprintf(&builtname, "%s_%s", name, param_name);
 180         if (ret < 0) {
 181                 ret = -ENOMEM;
 182                 goto error_ret;
 183         }
 184         ret = asprintf(&builtname_generic,
 185                        "%s_%s", generic_name, param_name);
 186         if (ret < 0) {
 187                 ret = -ENOMEM;
 188                 goto error_free_builtname;
 189         }
 190         dp = opendir(device_dir);
 191         if (dp == NULL) {
 192                 ret = -errno;
 193                 goto error_free_builtname_generic;
 194         }
 195         while (ent = readdir(dp), ent != NULL)
 196                 if ((strcmp(builtname, ent->d_name) == 0) ||
 197                     (strcmp(builtname_generic, ent->d_name) == 0)) {
 198                         ret = asprintf(&filename,
 199                                        "%s/%s", device_dir, ent->d_name);
 200                         if (ret < 0) {
 201                                 ret = -ENOMEM;
 202                                 goto error_closedir;
 203                         }
 204                         sysfsfp = fopen(filename, "r");
 205                         if (!sysfsfp) {
 206                                 ret = -errno;
 207                                 goto error_free_filename;
 208                         }
 209                         fscanf(sysfsfp, "%f", output);
 210                         break;
 211                 }
 212 error_free_filename:
 213         if (filename)
 214                 free(filename);
 215 error_closedir:
 216         closedir(dp);
 217 error_free_builtname_generic:
 218         free(builtname_generic);
 219 error_free_builtname:
 220         free(builtname);
 221 error_ret:
 222         return ret;
 223 }
 224
 225 /**
 226  * bsort_channel_array_by_index() - reorder so that the array is in index order
 227  *
 228  **/
 229
 230 void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
 231                                          int cnt)
 232 {
 233
 234         struct iio_channel_info temp;
 235         int x, y;
 236
 237         for (x = 0; x < cnt; x++)
 238                 for (y = 0; y < (cnt - 1); y++)
 239                         if ((*ci_array)[y].index > (*ci_array)[y+1].index) {
 240                                 temp = (*ci_array)[y + 1];
 241                                 (*ci_array)[y + 1] = (*ci_array)[y];
 242                                 (*ci_array)[y] = temp;
 243                         }
 244 }
 245
 246 /**
 247  * build_channel_array() - function to figure out what channels are present
 248  * @device_dir: the IIO device directory in sysfs
 249  * @
 250  **/
 251 int build_channel_array(const char *device_dir,
 252                               struct iio_channel_info **ci_array,
 253                               int *counter)
 254 {
 255         DIR *dp;
 256         FILE *sysfsfp;
 257         int count, i;
 258         struct iio_channel_info *current;
 259         int ret;
 260         const struct dirent *ent;
 261         char *scan_el_dir;
 262         char *filename;
 263
 264         *counter = 0;
 265         ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
 266         if (ret < 0) {
 267                 ret = -ENOMEM;
 268                 goto error_ret;
 269         }
 270         dp = opendir(scan_el_dir);
 271         if (dp == NULL) {
 272                 ret = -errno;
 273                 goto error_free_name;
 274         }
 275         while (ent = readdir(dp), ent != NULL)
 276                 if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
 277                            "_en") == 0) {
 278                         ret = asprintf(&filename,
 279                                        "%s/%s", scan_el_dir, ent->d_name);
 280                         if (ret < 0) {
 281                                 ret = -ENOMEM;
 282                                 goto error_close_dir;
 283                         }
 284                         sysfsfp = fopen(filename, "r");
 285                         if (sysfsfp == NULL) {
 286                                 ret = -errno;
 287                                 free(filename);
 288                                 goto error_close_dir;
 289                         }
 290                         fscanf(sysfsfp, "%i", &ret);
 291                         if (ret == 1)
 292                                 (*counter)++;
 293                         fclose(sysfsfp);
 294                         free(filename);
 295                 }
 296         *ci_array = malloc(sizeof(**ci_array) * (*counter));
 297         if (*ci_array == NULL) {
 298                 ret = -ENOMEM;
 299                 goto error_close_dir;
 300         }
 301         seekdir(dp, 0);
 302         count = 0;
 303         while (ent = readdir(dp), ent != NULL) {
 304                 if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
 305                            "_en") == 0) {
 306                         int current_enabled = 0;
 307
 308                         current = &(*ci_array)[count++];
 309                         ret = asprintf(&filename,
 310                                        "%s/%s", scan_el_dir, ent->d_name);
 311                         if (ret < 0) {
 312                                 ret = -ENOMEM;
 313                                 /* decrement count to avoid freeing name */
 314                                 count--;
 315                                 goto error_cleanup_array;
 316                         }
 317                         sysfsfp = fopen(filename, "r");
 318                         if (sysfsfp == NULL) {
 319                                 free(filename);
 320                                 ret = -errno;
 321                                 goto error_cleanup_array;
 322                         }
 323                         fscanf(sysfsfp, "%i", &current_enabled);
 324                         fclose(sysfsfp);
 325
 326                         if (!current_enabled) {
 327                                 free(filename);
 328                                 count--;
 329                                 continue;
 330                         }
 331
 332                         current->scale = 1.0;
 333                         current->offset = 0;
 334                         current->name = strndup(ent->d_name,
 335                                                 strlen(ent->d_name) -
 336                                                 strlen("_en"));
 337                         if (current->name == NULL) {
 338                                 free(filename);
 339                                 ret = -ENOMEM;
 340                                 goto error_cleanup_array;
 341                         }
 342                         /* Get the generic and specific name elements */
 343                         ret = iioutils_break_up_name(current->name,
 344                                                      &current->generic_name);
 345                         if (ret) {
 346                                 free(filename);
 347                                 goto error_cleanup_array;
 348                         }
 349                         ret = asprintf(&filename,
 350                                        "%s/%s_index",
 351                                        scan_el_dir,
 352                                        current->name);
 353                         if (ret < 0) {
 354                                 free(filename);
 355                                 ret = -ENOMEM;
 356                                 goto error_cleanup_array;
 357                         }
 358                         sysfsfp = fopen(filename, "r");
 359                         fscanf(sysfsfp, "%u", &current->index);
 360                         fclose(sysfsfp);
 361                         free(filename);
 362                         /* Find the scale */
 363                         ret = iioutils_get_param_float(&current->scale,
 364                                                        "scale",
 365                                                        device_dir,
 366                                                        current->name,
 367                                                        current->generic_name);
 368                         if (ret < 0)
 369                                 goto error_cleanup_array;
 370                         ret = iioutils_get_param_float(&current->offset,
 371                                                        "offset",
 372                                                        device_dir,
 373                                                        current->name,
 374                                                        current->generic_name);
 375                         if (ret < 0)
 376                                 goto error_cleanup_array;
 377                         ret = iioutils_get_type(&current->is_signed,
 378                                                 &current->bytes,
 379                                                 &current->bits_used,
 380                                                 &current->shift,
 381                                                 &current->mask,
 382                                                 &current->be,
 383                                                 device_dir,
 384                                                 current->name,
 385                                                 current->generic_name);
 386                 }
 387         }
 388
 389         closedir(dp);
 390         /* reorder so that the array is in index order */
 391         bsort_channel_array_by_index(ci_array, *counter);
 392
 393         return 0;
 394
 395 error_cleanup_array:
 396         for (i = count - 1;  i >= 0; i--)
 397                 free((*ci_array)[i].name);
 398         free(*ci_array);
 399 error_close_dir:
 400         closedir(dp);
 401 error_free_name:
 402         free(scan_el_dir);
 403 error_ret:
 404         return ret;
 405 }
 406
 407 /**
 408  * find_type_by_name() - function to match top level types by name
 409  * @name: top level type instance name
 410  * @type: the type of top level instance being sort
 411  *
 412  * Typical types this is used for are device and trigger.
 413  **/
 414 int find_type_by_name(const char *name, const char *type)
 415 {
 416         const struct dirent *ent;
 417         int number, numstrlen;
 418
 419         FILE *nameFile;
 420         DIR *dp;
 421         char thisname[IIO_MAX_NAME_LENGTH];
 422         char *filename;
 423
 424         dp = opendir(iio_dir);
 425         if (dp == NULL) {
 426                 printf("No industrialio devices available\n");
 427                 return -ENODEV;
 428         }
 429
 430         while (ent = readdir(dp), ent != NULL) {
 431                 if (strcmp(ent->d_name, ".") != 0 &&
 432                         strcmp(ent->d_name, "..") != 0 &&
 433                         strlen(ent->d_name) > strlen(type) &&
 434                         strncmp(ent->d_name, type, strlen(type)) == 0) {
 435                         numstrlen = sscanf(ent->d_name + strlen(type),
 436                                            "%d",
 437                                            &number);
 438                         /* verify the next character is not a colon */
 439                         if (strncmp(ent->d_name + strlen(type) + numstrlen,
 440                                         ":",
 441                                         1) != 0) {
 442                                 filename = malloc(strlen(iio_dir)
 443                                                 + strlen(type)
 444                                                 + numstrlen
 445                                                 + 6);
 446                                 if (filename == NULL) {
 447                                         closedir(dp);
 448                                         return -ENOMEM;
 449                                 }
 450                                 sprintf(filename, "%s%s%d/name",
 451                                         iio_dir,
 452                                         type,
 453                                         number);
 454                                 nameFile = fopen(filename, "r");
 455                                 if (!nameFile) {
 456                                         free(filename);
 457                                         continue;
 458                                 }
 459                                 free(filename);
 460                                 fscanf(nameFile, "%s", thisname);
 461                                 fclose(nameFile);
 462                                 if (strcmp(name, thisname) == 0) {
 463                                         closedir(dp);
 464                                         return number;
 465                                 }
 466                         }
 467                 }
 468         }
 469         closedir(dp);
 470         return -ENODEV;
 471 }
 472
 473 int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
 474 {
 475         int ret = 0;
 476         FILE *sysfsfp;
 477         int test;
 478         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 479
 480         if (temp == NULL)
 481                 return -ENOMEM;
 482         sprintf(temp, "%s/%s", basedir, filename);
 483         sysfsfp = fopen(temp, "w");
 484         if (sysfsfp == NULL) {
 485                 printf("failed to open %s\n", temp);
 486                 ret = -errno;
 487                 goto error_free;
 488         }
 489         fprintf(sysfsfp, "%d", val);
 490         fclose(sysfsfp);
 491         if (verify) {
 492                 sysfsfp = fopen(temp, "r");
 493                 if (sysfsfp == NULL) {
 494                         printf("failed to open %s\n", temp);
 495                         ret = -errno;
 496                         goto error_free;
 497                 }
 498                 fscanf(sysfsfp, "%d", &test);
 499                 fclose(sysfsfp);
 500                 if (test != val) {
 501                         printf("Possible failure in int write %d to %s%s\n",
 502                                 val,
 503                                 basedir,
 504                                 filename);
 505                         ret = -1;
 506                 }
 507         }
 508 error_free:
 509         free(temp);
 510         return ret;
 511 }
 512
 513 int write_sysfs_int(char *filename, char *basedir, int val)
 514 {
 515         return _write_sysfs_int(filename, basedir, val, 0);
 516 }
 517
 518 int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 519 {
 520         return _write_sysfs_int(filename, basedir, val, 1);
 521 }
 522
 523 int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 524 {
 525         int ret = 0;
 526         FILE  *sysfsfp;
 527         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 528
 529         if (temp == NULL) {
 530                 printf("Memory allocation failed\n");
 531                 return -ENOMEM;
 532         }
 533         sprintf(temp, "%s/%s", basedir, filename);
 534         sysfsfp = fopen(temp, "w");
 535         if (sysfsfp == NULL) {
 536                 printf("Could not open %s\n", temp);
 537                 ret = -errno;
 538                 goto error_free;
 539         }
 540         fprintf(sysfsfp, "%s", val);
 541         fclose(sysfsfp);
 542         if (verify) {
 543                 sysfsfp = fopen(temp, "r");
 544                 if (sysfsfp == NULL) {
 545                         printf("could not open file to verify\n");
 546                         ret = -errno;
 547                         goto error_free;
 548                 }
 549                 fscanf(sysfsfp, "%s", temp);
 550                 fclose(sysfsfp);
 551                 if (strcmp(temp, val) != 0) {
 552                         printf("Possible failure in string write of %s "
 553                                 "Should be %s "
 554                                 "written to %s\%s\n",
 555                                 temp,
 556                                 val,
 557                                 basedir,
 558                                 filename);
 559                         ret = -1;
 560                 }
 561         }
 562 error_free:
 563         free(temp);
 564
 565         return ret;
 566 }
 567
 568 /**
 569  * write_sysfs_string_and_verify() - string write, readback and verify
 570  * @filename: name of file to write to
 571  * @basedir: the sysfs directory in which the file is to be found
 572  * @val: the string to write
 573  **/
 574 int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
 575 {
 576         return _write_sysfs_string(filename, basedir, val, 1);
 577 }
 578
 579 int write_sysfs_string(char *filename, char *basedir, char *val)
 580 {
 581         return _write_sysfs_string(filename, basedir, val, 0);
 582 }
 583
 584 int read_sysfs_posint(char *filename, char *basedir)
 585 {
 586         int ret;
 587         FILE  *sysfsfp;
 588         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 589
 590         if (temp == NULL) {
 591                 printf("Memory allocation failed");
 592                 return -ENOMEM;
 593         }
 594         sprintf(temp, "%s/%s", basedir, filename);
 595         sysfsfp = fopen(temp, "r");
 596         if (sysfsfp == NULL) {
 597                 ret = -errno;
 598                 goto error_free;
 599         }
 600         fscanf(sysfsfp, "%d\n", &ret);
 601         fclose(sysfsfp);
 602 error_free:
 603         free(temp);
 604         return ret;
 605 }
 606
 607 int read_sysfs_float(char *filename, char *basedir, float *val)
 608 {
 609         int ret = 0;
 610         FILE  *sysfsfp;
 611         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 612
 613         if (temp == NULL) {
 614                 printf("Memory allocation failed");
 615                 return -ENOMEM;
 616         }
 617         sprintf(temp, "%s/%s", basedir, filename);
 618         sysfsfp = fopen(temp, "r");
 619         if (sysfsfp == NULL) {
 620                 ret = -errno;
 621                 goto error_free;
 622         }
 623         fscanf(sysfsfp, "%f\n", val);
 624         fclose(sysfsfp);
 625 error_free:
 626         free(temp);
 627         return ret;
 628 }
 629
 630 int read_sysfs_string(const char *filename, const char *basedir, char *str)
 631 {
 632         int ret = 0;
 633         FILE  *sysfsfp;
 634         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 635
 636         if (temp == NULL) {
 637                 printf("Memory allocation failed");
 638                 return -ENOMEM;
 639         }
 640         sprintf(temp, "%s/%s", basedir, filename);
 641         sysfsfp = fopen(temp, "r");
 642         if (sysfsfp == NULL) {
 643                 ret = -errno;
 644                 goto error_free;
 645         }
 646         fscanf(sysfsfp, "%s\n", str);
 647         fclose(sysfsfp);
 648 error_free:
 649         free(temp);
 650         return ret;
 651 }