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 #ifndef _IIO_UTILS_H
  10 #define _IIO_UTILS_H
  11
  12 #include <string.h>
  13 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <stdint.h>
  16 #include <dirent.h>
  17 #include <errno.h>
  18 #include <ctype.h>
  19 #include "iio_utils.h"
  20
  21 const char *iio_dir = "/sys/bus/iio/devices/";
  22
  23 static char * const iio_direction[] = {
  24         "in",
  25         "out",
  26 };
  27
  28 /**
  29  * iioutils_break_up_name() - extract generic name from full channel name
  30  * @full_name: the full channel name
  31  * @generic_name: the output generic channel name
  32  **/
  33 int iioutils_break_up_name(const char *full_name,
  34                                   char **generic_name)
  35 {
  36         char *current;
  37         char *w, *r;
  38         char *working, *prefix = "";
  39         int i;
  40
  41         for (i = 0; i < sizeof(iio_direction) / sizeof(iio_direction[0]); i++)
  42                 if (!strncmp(full_name, iio_direction[i],
  43                              strlen(iio_direction[i]))) {
  44                         prefix = iio_direction[i];
  45                         break;
  46                 }
  47
  48         current = strdup(full_name + strlen(prefix) + 1);
  49         working = strtok(current, "_\0");
  50
  51         w = working;
  52         r = working;
  53
  54         while (*r != '\0') {
  55                 if (!isdigit(*r)) {
  56                         *w = *r;
  57                         w++;
  58                 }
  59                 r++;
  60         }
  61         *w = '\0';
  62         asprintf(generic_name, "%s_%s", prefix, working);
  63         free(current);
  64
  65         return 0;
  66 }
  67
  68 /**
  69  * iioutils_get_type() - find and process _type attribute data
  70  * @is_signed: output whether channel is signed
  71  * @bytes: output how many bytes the channel storage occupies
  72  * @mask: output a bit mask for the raw data
  73  * @be: big endian
  74  * @device_dir: the iio device directory
  75  * @name: the channel name
  76  * @generic_name: the channel type name
  77  **/
  78 int iioutils_get_type(unsigned *is_signed,
  79                              unsigned *bytes,
  80                              unsigned *bits_used,
  81                              unsigned *shift,
  82                              uint64_t *mask,
  83                              unsigned *be,
  84                              const char *device_dir,
  85                              const char *name,
  86                              const char *generic_name)
  87 {
  88         FILE *sysfsfp;
  89         int ret;
  90         DIR *dp;
  91         char *scan_el_dir, *builtname, *builtname_generic, *filename = 0;
  92         char signchar, endianchar;
  93         unsigned padint;
  94         const struct dirent *ent;
  95
  96         ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
  97         if (ret < 0) {
  98                 ret = -ENOMEM;
  99                 goto error_ret;
 100         }
 101         ret = asprintf(&builtname, FORMAT_TYPE_FILE, name);
 102         if (ret < 0) {
 103                 ret = -ENOMEM;
 104                 goto error_free_scan_el_dir;
 105         }
 106         ret = asprintf(&builtname_generic, FORMAT_TYPE_FILE, generic_name);
 107         if (ret < 0) {
 108                 ret = -ENOMEM;
 109                 goto error_free_builtname;
 110         }
 111
 112         dp = opendir(scan_el_dir);
 113         if (dp == NULL) {
 114                 ret = -errno;
 115                 goto error_free_builtname_generic;
 116         }
 117         while (ent = readdir(dp), ent != NULL)
 118                 /*
 119                  * Do we allow devices to override a generic name with
 120                  * a specific one?
 121                  */
 122                 if ((strcmp(builtname, ent->d_name) == 0) ||
 123                     (strcmp(builtname_generic, ent->d_name) == 0)) {
 124                         ret = asprintf(&filename,
 125                                        "%s/%s", scan_el_dir, ent->d_name);
 126                         if (ret < 0) {
 127                                 ret = -ENOMEM;
 128                                 goto error_closedir;
 129                         }
 130                         sysfsfp = fopen(filename, "r");
 131                         if (sysfsfp == NULL) {
 132                                 printf("failed to open %s\n", filename);
 133                                 ret = -errno;
 134                                 goto error_free_filename;
 135                         }
 136
 137                         ret = fscanf(sysfsfp,
 138                                      "%ce:%c%u/%u>>%u",
 139                                      &endianchar,
 140                                      &signchar,
 141                                      bits_used,
 142                                      &padint, shift);
 143                         if (ret < 0) {
 144                                 printf("failed to pass scan type description\n");
 145                                 ret = -errno;
 146                                 goto error_close_sysfsfp;
 147                         }
 148                         *be = (endianchar == 'b');
 149                         *bytes = padint / 8;
 150                         if (*bits_used == 64)
 151                                 *mask = ~0;
 152                         else
 153                                 *mask = (1 << *bits_used) - 1;
 154                         if (signchar == 's')
 155                                 *is_signed = 1;
 156                         else
 157                                 *is_signed = 0;
 158                         fclose(sysfsfp);
 159                         free(filename);
 160
 161                         filename = 0;
 162                         sysfsfp = 0;
 163                 }
 164 error_close_sysfsfp:
 165         if (sysfsfp)
 166                 fclose(sysfsfp);
 167 error_free_filename:
 168         if (filename)
 169                 free(filename);
 170 error_closedir:
 171         closedir(dp);
 172 error_free_builtname_generic:
 173         free(builtname_generic);
 174 error_free_builtname:
 175         free(builtname);
 176 error_free_scan_el_dir:
 177         free(scan_el_dir);
 178 error_ret:
 179         return ret;
 180 }
 181
 182 int iioutils_get_param_float(float *output,
 183                                     const char *param_name,
 184                                     const char *device_dir,
 185                                     const char *name,
 186                                     const char *generic_name)
 187 {
 188         FILE *sysfsfp;
 189         int ret;
 190         DIR *dp;
 191         char *builtname, *builtname_generic;
 192         char *filename = NULL;
 193         const struct dirent *ent;
 194
 195         ret = asprintf(&builtname, "%s_%s", name, param_name);
 196         if (ret < 0) {
 197                 ret = -ENOMEM;
 198                 goto error_ret;
 199         }
 200         ret = asprintf(&builtname_generic,
 201                        "%s_%s", generic_name, param_name);
 202         if (ret < 0) {
 203                 ret = -ENOMEM;
 204                 goto error_free_builtname;
 205         }
 206         dp = opendir(device_dir);
 207         if (dp == NULL) {
 208                 ret = -errno;
 209                 goto error_free_builtname_generic;
 210         }
 211         while (ent = readdir(dp), ent != NULL)
 212                 if ((strcmp(builtname, ent->d_name) == 0) ||
 213                     (strcmp(builtname_generic, ent->d_name) == 0)) {
 214                         ret = asprintf(&filename,
 215                                        "%s/%s", device_dir, ent->d_name);
 216                         if (ret < 0) {
 217                                 ret = -ENOMEM;
 218                                 goto error_closedir;
 219                         }
 220                         sysfsfp = fopen(filename, "r");
 221                         if (!sysfsfp) {
 222                                 ret = -errno;
 223                                 goto error_free_filename;
 224                         }
 225                         fscanf(sysfsfp, "%f", output);
 226                         break;
 227                 }
 228 error_free_filename:
 229         if (filename)
 230                 free(filename);
 231 error_closedir:
 232         closedir(dp);
 233 error_free_builtname_generic:
 234         free(builtname_generic);
 235 error_free_builtname:
 236         free(builtname);
 237 error_ret:
 238         return ret;
 239 }
 240
 241 /**
 242  * bsort_channel_array_by_index() - reorder so that the array is in index order
 243  *
 244  **/
 245
 246 void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
 247                                          int cnt)
 248 {
 249
 250         struct iio_channel_info temp;
 251         int x, y;
 252
 253         for (x = 0; x < cnt; x++)
 254                 for (y = 0; y < (cnt - 1); y++)
 255                         if ((*ci_array)[y].index > (*ci_array)[y+1].index) {
 256                                 temp = (*ci_array)[y + 1];
 257                                 (*ci_array)[y + 1] = (*ci_array)[y];
 258                                 (*ci_array)[y] = temp;
 259                         }
 260 }
 261
 262 /**
 263  * build_channel_array() - function to figure out what channels are present
 264  * @device_dir: the IIO device directory in sysfs
 265  * @
 266  **/
 267 int build_channel_array(const char *device_dir,
 268                               struct iio_channel_info **ci_array,
 269                               int *counter)
 270 {
 271         DIR *dp;
 272         FILE *sysfsfp;
 273         int count, i;
 274         struct iio_channel_info *current;
 275         int ret;
 276         const struct dirent *ent;
 277         char *scan_el_dir;
 278         char *filename;
 279
 280         *counter = 0;
 281         ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
 282         if (ret < 0) {
 283                 ret = -ENOMEM;
 284                 goto error_ret;
 285         }
 286         dp = opendir(scan_el_dir);
 287         if (dp == NULL) {
 288                 ret = -errno;
 289                 goto error_free_name;
 290         }
 291         while (ent = readdir(dp), ent != NULL)
 292                 if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
 293                            "_en") == 0) {
 294                         ret = asprintf(&filename,
 295                                        "%s/%s", scan_el_dir, ent->d_name);
 296                         if (ret < 0) {
 297                                 ret = -ENOMEM;
 298                                 goto error_close_dir;
 299                         }
 300                         sysfsfp = fopen(filename, "r");
 301                         if (sysfsfp == NULL) {
 302                                 ret = -errno;
 303                                 free(filename);
 304                                 goto error_close_dir;
 305                         }
 306                         fscanf(sysfsfp, "%i", &ret);
 307                         if (ret == 1)
 308                                 (*counter)++;
 309                         fclose(sysfsfp);
 310                         free(filename);
 311                 }
 312         *ci_array = malloc(sizeof(**ci_array) * (*counter));
 313         if (*ci_array == NULL) {
 314                 ret = -ENOMEM;
 315                 goto error_close_dir;
 316         }
 317         seekdir(dp, 0);
 318         count = 0;
 319         while (ent = readdir(dp), ent != NULL) {
 320                 if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
 321                            "_en") == 0) {
 322                         int current_enabled = 0;
 323
 324                         current = &(*ci_array)[count++];
 325                         ret = asprintf(&filename,
 326                                        "%s/%s", scan_el_dir, ent->d_name);
 327                         if (ret < 0) {
 328                                 ret = -ENOMEM;
 329                                 /* decrement count to avoid freeing name */
 330                                 count--;
 331                                 goto error_cleanup_array;
 332                         }
 333                         sysfsfp = fopen(filename, "r");
 334                         if (sysfsfp == NULL) {
 335                                 free(filename);
 336                                 ret = -errno;
 337                                 goto error_cleanup_array;
 338                         }
 339                         fscanf(sysfsfp, "%i", &current_enabled);
 340                         fclose(sysfsfp);
 341
 342                         if (!current_enabled) {
 343                                 free(filename);
 344                                 count--;
 345                                 continue;
 346                         }
 347
 348                         current->scale = 1.0;
 349                         current->offset = 0;
 350                         current->name = strndup(ent->d_name,
 351                                                 strlen(ent->d_name) -
 352                                                 strlen("_en"));
 353                         if (current->name == NULL) {
 354                                 free(filename);
 355                                 ret = -ENOMEM;
 356                                 goto error_cleanup_array;
 357                         }
 358                         /* Get the generic and specific name elements */
 359                         ret = iioutils_break_up_name(current->name,
 360                                                      &current->generic_name);
 361                         if (ret) {
 362                                 free(filename);
 363                                 goto error_cleanup_array;
 364                         }
 365                         ret = asprintf(&filename,
 366                                        "%s/%s_index",
 367                                        scan_el_dir,
 368                                        current->name);
 369                         if (ret < 0) {
 370                                 free(filename);
 371                                 ret = -ENOMEM;
 372                                 goto error_cleanup_array;
 373                         }
 374                         sysfsfp = fopen(filename, "r");
 375                         fscanf(sysfsfp, "%u", &current->index);
 376                         fclose(sysfsfp);
 377                         free(filename);
 378                         /* Find the scale */
 379                         ret = iioutils_get_param_float(&current->scale,
 380                                                        "scale",
 381                                                        device_dir,
 382                                                        current->name,
 383                                                        current->generic_name);
 384                         if (ret < 0)
 385                                 goto error_cleanup_array;
 386                         ret = iioutils_get_param_float(&current->offset,
 387                                                        "offset",
 388                                                        device_dir,
 389                                                        current->name,
 390                                                        current->generic_name);
 391                         if (ret < 0)
 392                                 goto error_cleanup_array;
 393                         ret = iioutils_get_type(&current->is_signed,
 394                                                 &current->bytes,
 395                                                 &current->bits_used,
 396                                                 &current->shift,
 397                                                 &current->mask,
 398                                                 &current->be,
 399                                                 device_dir,
 400                                                 current->name,
 401                                                 current->generic_name);
 402                 }
 403         }
 404
 405         closedir(dp);
 406         free(scan_el_dir);
 407         /* reorder so that the array is in index order */
 408         bsort_channel_array_by_index(ci_array, *counter);
 409
 410         return 0;
 411
 412 error_cleanup_array:
 413         for (i = count - 1;  i >= 0; i--)
 414                 free((*ci_array)[i].name);
 415         free(*ci_array);
 416 error_close_dir:
 417         closedir(dp);
 418 error_free_name:
 419         free(scan_el_dir);
 420 error_ret:
 421         return ret;
 422 }
 423
 424 /**
 425  * find_type_by_name() - function to match top level types by name
 426  * @name: top level type instance name
 427  * @type: the type of top level instance being sort
 428  *
 429  * Typical types this is used for are device and trigger.
 430  **/
 431 int find_type_by_name(const char *name, const char *type)
 432 {
 433         const struct dirent *ent;
 434         int number, numstrlen;
 435
 436         FILE *nameFile;
 437         DIR *dp;
 438         char thisname[IIO_MAX_NAME_LENGTH];
 439         char *filename;
 440
 441         dp = opendir(iio_dir);
 442         if (dp == NULL) {
 443                 printf("No industrialio devices available\n");
 444                 return -ENODEV;
 445         }
 446
 447         while (ent = readdir(dp), ent != NULL) {
 448                 if (strcmp(ent->d_name, ".") != 0 &&
 449                         strcmp(ent->d_name, "..") != 0 &&
 450                         strlen(ent->d_name) > strlen(type) &&
 451                         strncmp(ent->d_name, type, strlen(type)) == 0) {
 452                         numstrlen = sscanf(ent->d_name + strlen(type),
 453                                            "%d",
 454                                            &number);
 455                         /* verify the next character is not a colon */
 456                         if (strncmp(ent->d_name + strlen(type) + numstrlen,
 457                                         ":",
 458                                         1) != 0) {
 459                                 filename = malloc(strlen(iio_dir)
 460                                                 + strlen(type)
 461                                                 + numstrlen
 462                                                 + 6);
 463                                 if (filename == NULL) {
 464                                         closedir(dp);
 465                                         return -ENOMEM;
 466                                 }
 467                                 sprintf(filename, "%s%s%d/name",
 468                                         iio_dir,
 469                                         type,
 470                                         number);
 471                                 nameFile = fopen(filename, "r");
 472                                 if (!nameFile) {
 473                                         free(filename);
 474                                         continue;
 475                                 }
 476                                 free(filename);
 477                                 fscanf(nameFile, "%s", thisname);
 478                                 fclose(nameFile);
 479                                 if (strcmp(name, thisname) == 0) {
 480                                         closedir(dp);
 481                                         return number;
 482                                 }
 483                         }
 484                 }
 485         }
 486         closedir(dp);
 487         return -ENODEV;
 488 }
 489
 490 int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
 491 {
 492         int ret = 0;
 493         FILE *sysfsfp;
 494         int test;
 495         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 496
 497         if (temp == NULL)
 498                 return -ENOMEM;
 499         sprintf(temp, "%s/%s", basedir, filename);
 500         sysfsfp = fopen(temp, "w");
 501         if (sysfsfp == NULL) {
 502                 printf("failed to open %s\n", temp);
 503                 ret = -errno;
 504                 goto error_free;
 505         }
 506         fprintf(sysfsfp, "%d", val);
 507         fclose(sysfsfp);
 508         if (verify) {
 509                 sysfsfp = fopen(temp, "r");
 510                 if (sysfsfp == NULL) {
 511                         printf("failed to open %s\n", temp);
 512                         ret = -errno;
 513                         goto error_free;
 514                 }
 515                 fscanf(sysfsfp, "%d", &test);
 516                 fclose(sysfsfp);
 517                 if (test != val) {
 518                         printf("Possible failure in int write %d to %s%s\n",
 519                                 val,
 520                                 basedir,
 521                                 filename);
 522                         ret = -1;
 523                 }
 524         }
 525 error_free:
 526         free(temp);
 527         return ret;
 528 }
 529
 530 int write_sysfs_int(char *filename, char *basedir, int val)
 531 {
 532         return _write_sysfs_int(filename, basedir, val, 0);
 533 }
 534
 535 int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 536 {
 537         return _write_sysfs_int(filename, basedir, val, 1);
 538 }
 539
 540 int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 541 {
 542         int ret = 0;
 543         FILE  *sysfsfp;
 544         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 545
 546         if (temp == NULL) {
 547                 printf("Memory allocation failed\n");
 548                 return -ENOMEM;
 549         }
 550         sprintf(temp, "%s/%s", basedir, filename);
 551         sysfsfp = fopen(temp, "w");
 552         if (sysfsfp == NULL) {
 553                 printf("Could not open %s\n", temp);
 554                 ret = -errno;
 555                 goto error_free;
 556         }
 557         fprintf(sysfsfp, "%s", val);
 558         fclose(sysfsfp);
 559         if (verify) {
 560                 sysfsfp = fopen(temp, "r");
 561                 if (sysfsfp == NULL) {
 562                         printf("could not open file to verify\n");
 563                         ret = -errno;
 564                         goto error_free;
 565                 }
 566                 fscanf(sysfsfp, "%s", temp);
 567                 fclose(sysfsfp);
 568                 if (strcmp(temp, val) != 0) {
 569                         printf("Possible failure in string write of %s "
 570                                 "Should be %s "
 571                                 "written to %s\%s\n",
 572                                 temp,
 573                                 val,
 574                                 basedir,
 575                                 filename);
 576                         ret = -1;
 577                 }
 578         }
 579 error_free:
 580         free(temp);
 581
 582         return ret;
 583 }
 584
 585 /**
 586  * write_sysfs_string_and_verify() - string write, readback and verify
 587  * @filename: name of file to write to
 588  * @basedir: the sysfs directory in which the file is to be found
 589  * @val: the string to write
 590  **/
 591 int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
 592 {
 593         return _write_sysfs_string(filename, basedir, val, 1);
 594 }
 595
 596 int write_sysfs_string(char *filename, char *basedir, char *val)
 597 {
 598         return _write_sysfs_string(filename, basedir, val, 0);
 599 }
 600
 601 int read_sysfs_posint(char *filename, char *basedir)
 602 {
 603         int ret;
 604         FILE  *sysfsfp;
 605         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 606
 607         if (temp == NULL) {
 608                 printf("Memory allocation failed");
 609                 return -ENOMEM;
 610         }
 611         sprintf(temp, "%s/%s", basedir, filename);
 612         sysfsfp = fopen(temp, "r");
 613         if (sysfsfp == NULL) {
 614                 ret = -errno;
 615                 goto error_free;
 616         }
 617         fscanf(sysfsfp, "%d\n", &ret);
 618         fclose(sysfsfp);
 619 error_free:
 620         free(temp);
 621         return ret;
 622 }
 623
 624 int read_sysfs_float(char *filename, char *basedir, float *val)
 625 {
 626         int ret = 0;
 627         FILE  *sysfsfp;
 628         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 629
 630         if (temp == NULL) {
 631                 printf("Memory allocation failed");
 632                 return -ENOMEM;
 633         }
 634         sprintf(temp, "%s/%s", basedir, filename);
 635         sysfsfp = fopen(temp, "r");
 636         if (sysfsfp == NULL) {
 637                 ret = -errno;
 638                 goto error_free;
 639         }
 640         fscanf(sysfsfp, "%f\n", val);
 641         fclose(sysfsfp);
 642 error_free:
 643         free(temp);
 644         return ret;
 645 }
 646
 647 int read_sysfs_string(const char *filename, const char *basedir, char *str)
 648 {
 649         int ret = 0;
 650         FILE  *sysfsfp;
 651         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 652
 653         if (temp == NULL) {
 654                 printf("Memory allocation failed");
 655                 return -ENOMEM;
 656         }
 657         sprintf(temp, "%s/%s", basedir, filename);
 658         sysfsfp = fopen(temp, "r");
 659         if (sysfsfp == NULL) {
 660                 ret = -errno;
 661                 goto error_free;
 662         }
 663         fscanf(sysfsfp, "%s\n", str);
 664         fclose(sysfsfp);
 665 error_free:
 666         free(temp);
 667         return ret;
 668 }
 669
 670 #endif /* _IIO_UTILS_H */