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                                 ret = -errno;
 133                                 printf("failed to open %s\n", filename);
 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                                 ret = -errno;
 145                                 printf("failed to pass scan type description\n");
 146                                 goto error_close_sysfsfp;
 147                         } else if (ret != 5) {
 148                                 ret = -EIO;
 149                                 printf("scan type description didn't match\n");
 150                                 goto error_close_sysfsfp;
 151                         }
 152                         *be = (endianchar == 'b');
 153                         *bytes = padint / 8;
 154                         if (*bits_used == 64)
 155                                 *mask = ~0;
 156                         else
 157                                 *mask = (1 << *bits_used) - 1;
 158                         if (signchar == 's')
 159                                 *is_signed = 1;
 160                         else
 161                                 *is_signed = 0;
 162                         fclose(sysfsfp);
 163                         free(filename);
 164
 165                         filename = 0;
 166                         sysfsfp = 0;
 167                 }
 168 error_close_sysfsfp:
 169         if (sysfsfp)
 170                 fclose(sysfsfp);
 171 error_free_filename:
 172         if (filename)
 173                 free(filename);
 174 error_closedir:
 175         closedir(dp);
 176 error_free_builtname_generic:
 177         free(builtname_generic);
 178 error_free_builtname:
 179         free(builtname);
 180 error_free_scan_el_dir:
 181         free(scan_el_dir);
 182 error_ret:
 183         return ret;
 184 }
 185
 186 int iioutils_get_param_float(float *output,
 187                                     const char *param_name,
 188                                     const char *device_dir,
 189                                     const char *name,
 190                                     const char *generic_name)
 191 {
 192         FILE *sysfsfp;
 193         int ret;
 194         DIR *dp;
 195         char *builtname, *builtname_generic;
 196         char *filename = NULL;
 197         const struct dirent *ent;
 198
 199         ret = asprintf(&builtname, "%s_%s", name, param_name);
 200         if (ret < 0) {
 201                 ret = -ENOMEM;
 202                 goto error_ret;
 203         }
 204         ret = asprintf(&builtname_generic,
 205                        "%s_%s", generic_name, param_name);
 206         if (ret < 0) {
 207                 ret = -ENOMEM;
 208                 goto error_free_builtname;
 209         }
 210         dp = opendir(device_dir);
 211         if (dp == NULL) {
 212                 ret = -errno;
 213                 goto error_free_builtname_generic;
 214         }
 215         while (ent = readdir(dp), ent != NULL)
 216                 if ((strcmp(builtname, ent->d_name) == 0) ||
 217                     (strcmp(builtname_generic, ent->d_name) == 0)) {
 218                         ret = asprintf(&filename,
 219                                        "%s/%s", device_dir, ent->d_name);
 220                         if (ret < 0) {
 221                                 ret = -ENOMEM;
 222                                 goto error_closedir;
 223                         }
 224                         sysfsfp = fopen(filename, "r");
 225                         if (!sysfsfp) {
 226                                 ret = -errno;
 227                                 goto error_free_filename;
 228                         }
 229                         fscanf(sysfsfp, "%f", output);
 230                         break;
 231                 }
 232 error_free_filename:
 233         if (filename)
 234                 free(filename);
 235 error_closedir:
 236         closedir(dp);
 237 error_free_builtname_generic:
 238         free(builtname_generic);
 239 error_free_builtname:
 240         free(builtname);
 241 error_ret:
 242         return ret;
 243 }
 244
 245 /**
 246  * bsort_channel_array_by_index() - reorder so that the array is in index order
 247  *
 248  **/
 249
 250 void bsort_channel_array_by_index(struct iio_channel_info **ci_array,
 251                                          int cnt)
 252 {
 253
 254         struct iio_channel_info temp;
 255         int x, y;
 256
 257         for (x = 0; x < cnt; x++)
 258                 for (y = 0; y < (cnt - 1); y++)
 259                         if ((*ci_array)[y].index > (*ci_array)[y+1].index) {
 260                                 temp = (*ci_array)[y + 1];
 261                                 (*ci_array)[y + 1] = (*ci_array)[y];
 262                                 (*ci_array)[y] = temp;
 263                         }
 264 }
 265
 266 /**
 267  * build_channel_array() - function to figure out what channels are present
 268  * @device_dir: the IIO device directory in sysfs
 269  * @
 270  **/
 271 int build_channel_array(const char *device_dir,
 272                               struct iio_channel_info **ci_array,
 273                               int *counter)
 274 {
 275         DIR *dp;
 276         FILE *sysfsfp;
 277         int count, i;
 278         struct iio_channel_info *current;
 279         int ret;
 280         const struct dirent *ent;
 281         char *scan_el_dir;
 282         char *filename;
 283
 284         *counter = 0;
 285         ret = asprintf(&scan_el_dir, FORMAT_SCAN_ELEMENTS_DIR, device_dir);
 286         if (ret < 0) {
 287                 ret = -ENOMEM;
 288                 goto error_ret;
 289         }
 290         dp = opendir(scan_el_dir);
 291         if (dp == NULL) {
 292                 ret = -errno;
 293                 goto error_free_name;
 294         }
 295         while (ent = readdir(dp), ent != NULL)
 296                 if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
 297                            "_en") == 0) {
 298                         ret = asprintf(&filename,
 299                                        "%s/%s", scan_el_dir, ent->d_name);
 300                         if (ret < 0) {
 301                                 ret = -ENOMEM;
 302                                 goto error_close_dir;
 303                         }
 304                         sysfsfp = fopen(filename, "r");
 305                         if (sysfsfp == NULL) {
 306                                 ret = -errno;
 307                                 free(filename);
 308                                 goto error_close_dir;
 309                         }
 310                         fscanf(sysfsfp, "%i", &ret);
 311                         if (ret == 1)
 312                                 (*counter)++;
 313                         fclose(sysfsfp);
 314                         free(filename);
 315                 }
 316         *ci_array = malloc(sizeof(**ci_array) * (*counter));
 317         if (*ci_array == NULL) {
 318                 ret = -ENOMEM;
 319                 goto error_close_dir;
 320         }
 321         seekdir(dp, 0);
 322         count = 0;
 323         while (ent = readdir(dp), ent != NULL) {
 324                 if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"),
 325                            "_en") == 0) {
 326                         int current_enabled = 0;
 327
 328                         current = &(*ci_array)[count++];
 329                         ret = asprintf(&filename,
 330                                        "%s/%s", scan_el_dir, ent->d_name);
 331                         if (ret < 0) {
 332                                 ret = -ENOMEM;
 333                                 /* decrement count to avoid freeing name */
 334                                 count--;
 335                                 goto error_cleanup_array;
 336                         }
 337                         sysfsfp = fopen(filename, "r");
 338                         if (sysfsfp == NULL) {
 339                                 ret = -errno;
 340                                 free(filename);
 341                                 count--;
 342                                 goto error_cleanup_array;
 343                         }
 344                         fscanf(sysfsfp, "%i", &current_enabled);
 345                         fclose(sysfsfp);
 346
 347                         if (!current_enabled) {
 348                                 free(filename);
 349                                 count--;
 350                                 continue;
 351                         }
 352
 353                         current->scale = 1.0;
 354                         current->offset = 0;
 355                         current->name = strndup(ent->d_name,
 356                                                 strlen(ent->d_name) -
 357                                                 strlen("_en"));
 358                         if (current->name == NULL) {
 359                                 free(filename);
 360                                 ret = -ENOMEM;
 361                                 count--;
 362                                 goto error_cleanup_array;
 363                         }
 364                         /* Get the generic and specific name elements */
 365                         ret = iioutils_break_up_name(current->name,
 366                                                      &current->generic_name);
 367                         if (ret) {
 368                                 free(filename);
 369                                 free(current->name);
 370                                 count--;
 371                                 goto error_cleanup_array;
 372                         }
 373                         ret = asprintf(&filename,
 374                                        "%s/%s_index",
 375                                        scan_el_dir,
 376                                        current->name);
 377                         if (ret < 0) {
 378                                 free(filename);
 379                                 ret = -ENOMEM;
 380                                 goto error_cleanup_array;
 381                         }
 382                         sysfsfp = fopen(filename, "r");
 383                         fscanf(sysfsfp, "%u", &current->index);
 384                         fclose(sysfsfp);
 385                         free(filename);
 386                         /* Find the scale */
 387                         ret = iioutils_get_param_float(&current->scale,
 388                                                        "scale",
 389                                                        device_dir,
 390                                                        current->name,
 391                                                        current->generic_name);
 392                         if (ret < 0)
 393                                 goto error_cleanup_array;
 394                         ret = iioutils_get_param_float(&current->offset,
 395                                                        "offset",
 396                                                        device_dir,
 397                                                        current->name,
 398                                                        current->generic_name);
 399                         if (ret < 0)
 400                                 goto error_cleanup_array;
 401                         ret = iioutils_get_type(&current->is_signed,
 402                                                 &current->bytes,
 403                                                 &current->bits_used,
 404                                                 &current->shift,
 405                                                 &current->mask,
 406                                                 &current->be,
 407                                                 device_dir,
 408                                                 current->name,
 409                                                 current->generic_name);
 410                 }
 411         }
 412
 413         closedir(dp);
 414         free(scan_el_dir);
 415         /* reorder so that the array is in index order */
 416         bsort_channel_array_by_index(ci_array, *counter);
 417
 418         return 0;
 419
 420 error_cleanup_array:
 421         for (i = count - 1;  i >= 0; i--) {
 422                 free((*ci_array)[i].name);
 423                 free((*ci_array)[i].generic_name);
 424         }
 425         free(*ci_array);
 426 error_close_dir:
 427         closedir(dp);
 428 error_free_name:
 429         free(scan_el_dir);
 430 error_ret:
 431         return ret;
 432 }
 433
 434 int calc_digits(int num)
 435 {
 436         int count = 0;
 437
 438         while (num != 0) {
 439                 num /= 10;
 440                 count++;
 441         }
 442
 443         return count;
 444 }
 445
 446 /**
 447  * find_type_by_name() - function to match top level types by name
 448  * @name: top level type instance name
 449  * @type: the type of top level instance being sort
 450  *
 451  * Typical types this is used for are device and trigger.
 452  **/
 453 int find_type_by_name(const char *name, const char *type)
 454 {
 455         const struct dirent *ent;
 456         int number, numstrlen, ret;
 457
 458         FILE *nameFile;
 459         DIR *dp;
 460         char thisname[IIO_MAX_NAME_LENGTH];
 461         char *filename;
 462
 463         dp = opendir(iio_dir);
 464         if (dp == NULL) {
 465                 printf("No industrialio devices available\n");
 466                 return -ENODEV;
 467         }
 468
 469         while (ent = readdir(dp), ent != NULL) {
 470                 if (strcmp(ent->d_name, ".") != 0 &&
 471                         strcmp(ent->d_name, "..") != 0 &&
 472                         strlen(ent->d_name) > strlen(type) &&
 473                         strncmp(ent->d_name, type, strlen(type)) == 0) {
 474                         errno = 0;
 475                         ret = sscanf(ent->d_name + strlen(type), "%d", &number);
 476                         if (ret < 0) {
 477                                 ret = -errno;
 478                                 printf("failed to read element number\n");
 479                                 goto error_close_dir;
 480                         } else if (ret != 1) {
 481                                 ret = -EIO;
 482                                 printf("failed to match element number\n");
 483                                 goto error_close_dir;
 484                         }
 485
 486                         numstrlen = calc_digits(number);
 487                         /* verify the next character is not a colon */
 488                         if (strncmp(ent->d_name + strlen(type) + numstrlen,
 489                                         ":",
 490                                         1) != 0) {
 491                                 filename = malloc(strlen(iio_dir)
 492                                                 + strlen(type)
 493                                                 + numstrlen
 494                                                 + 6);
 495                                 if (filename == NULL) {
 496                                         closedir(dp);
 497                                         return -ENOMEM;
 498                                 }
 499                                 sprintf(filename, "%s%s%d/name",
 500                                         iio_dir,
 501                                         type,
 502                                         number);
 503                                 nameFile = fopen(filename, "r");
 504                                 if (!nameFile) {
 505                                         free(filename);
 506                                         continue;
 507                                 }
 508                                 free(filename);
 509                                 fscanf(nameFile, "%s", thisname);
 510                                 fclose(nameFile);
 511                                 if (strcmp(name, thisname) == 0) {
 512                                         closedir(dp);
 513                                         return number;
 514                                 }
 515                         }
 516                 }
 517         }
 518         closedir(dp);
 519         return -ENODEV;
 520
 521 error_close_dir:
 522         if (closedir(dp) == -1)
 523                 perror("find_type_by_name(): Failed to close directory");
 524         return ret;
 525 }
 526
 527 int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
 528 {
 529         int ret = 0;
 530         FILE *sysfsfp;
 531         int test;
 532         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 533
 534         if (temp == NULL)
 535                 return -ENOMEM;
 536         sprintf(temp, "%s/%s", basedir, filename);
 537         sysfsfp = fopen(temp, "w");
 538         if (sysfsfp == NULL) {
 539                 ret = -errno;
 540                 printf("failed to open %s\n", temp);
 541                 goto error_free;
 542         }
 543         fprintf(sysfsfp, "%d", val);
 544         fclose(sysfsfp);
 545         if (verify) {
 546                 sysfsfp = fopen(temp, "r");
 547                 if (sysfsfp == NULL) {
 548                         ret = -errno;
 549                         printf("failed to open %s\n", temp);
 550                         goto error_free;
 551                 }
 552                 fscanf(sysfsfp, "%d", &test);
 553                 fclose(sysfsfp);
 554                 if (test != val) {
 555                         printf("Possible failure in int write %d to %s%s\n",
 556                                 val,
 557                                 basedir,
 558                                 filename);
 559                         ret = -1;
 560                 }
 561         }
 562 error_free:
 563         free(temp);
 564         return ret;
 565 }
 566
 567 int write_sysfs_int(char *filename, char *basedir, int val)
 568 {
 569         return _write_sysfs_int(filename, basedir, val, 0);
 570 }
 571
 572 int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 573 {
 574         return _write_sysfs_int(filename, basedir, val, 1);
 575 }
 576
 577 int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 578 {
 579         int ret = 0;
 580         FILE  *sysfsfp;
 581         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 582
 583         if (temp == NULL) {
 584                 printf("Memory allocation failed\n");
 585                 return -ENOMEM;
 586         }
 587         sprintf(temp, "%s/%s", basedir, filename);
 588         sysfsfp = fopen(temp, "w");
 589         if (sysfsfp == NULL) {
 590                 ret = -errno;
 591                 printf("Could not open %s\n", temp);
 592                 goto error_free;
 593         }
 594         fprintf(sysfsfp, "%s", val);
 595         fclose(sysfsfp);
 596         if (verify) {
 597                 sysfsfp = fopen(temp, "r");
 598                 if (sysfsfp == NULL) {
 599                         ret = -errno;
 600                         printf("could not open file to verify\n");
 601                         goto error_free;
 602                 }
 603                 fscanf(sysfsfp, "%s", temp);
 604                 fclose(sysfsfp);
 605                 if (strcmp(temp, val) != 0) {
 606                         printf("Possible failure in string write of %s "
 607                                 "Should be %s "
 608                                 "written to %s\%s\n",
 609                                 temp,
 610                                 val,
 611                                 basedir,
 612                                 filename);
 613                         ret = -1;
 614                 }
 615         }
 616 error_free:
 617         free(temp);
 618
 619         return ret;
 620 }
 621
 622 /**
 623  * write_sysfs_string_and_verify() - string write, readback and verify
 624  * @filename: name of file to write to
 625  * @basedir: the sysfs directory in which the file is to be found
 626  * @val: the string to write
 627  **/
 628 int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
 629 {
 630         return _write_sysfs_string(filename, basedir, val, 1);
 631 }
 632
 633 int write_sysfs_string(char *filename, char *basedir, char *val)
 634 {
 635         return _write_sysfs_string(filename, basedir, val, 0);
 636 }
 637
 638 int read_sysfs_posint(char *filename, char *basedir)
 639 {
 640         int ret;
 641         FILE  *sysfsfp;
 642         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 643
 644         if (temp == NULL) {
 645                 printf("Memory allocation failed");
 646                 return -ENOMEM;
 647         }
 648         sprintf(temp, "%s/%s", basedir, filename);
 649         sysfsfp = fopen(temp, "r");
 650         if (sysfsfp == NULL) {
 651                 ret = -errno;
 652                 goto error_free;
 653         }
 654         fscanf(sysfsfp, "%d\n", &ret);
 655         fclose(sysfsfp);
 656 error_free:
 657         free(temp);
 658         return ret;
 659 }
 660
 661 int read_sysfs_float(char *filename, char *basedir, float *val)
 662 {
 663         int ret = 0;
 664         FILE  *sysfsfp;
 665         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 666
 667         if (temp == NULL) {
 668                 printf("Memory allocation failed");
 669                 return -ENOMEM;
 670         }
 671         sprintf(temp, "%s/%s", basedir, filename);
 672         sysfsfp = fopen(temp, "r");
 673         if (sysfsfp == NULL) {
 674                 ret = -errno;
 675                 goto error_free;
 676         }
 677         fscanf(sysfsfp, "%f\n", val);
 678         fclose(sysfsfp);
 679 error_free:
 680         free(temp);
 681         return ret;
 682 }
 683
 684 int read_sysfs_string(const char *filename, const char *basedir, char *str)
 685 {
 686         int ret = 0;
 687         FILE  *sysfsfp;
 688         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 689
 690         if (temp == NULL) {
 691                 printf("Memory allocation failed");
 692                 return -ENOMEM;
 693         }
 694         sprintf(temp, "%s/%s", basedir, filename);
 695         sysfsfp = fopen(temp, "r");
 696         if (sysfsfp == NULL) {
 697                 ret = -errno;
 698                 goto error_free;
 699         }
 700         fscanf(sysfsfp, "%s\n", str);
 701         fclose(sysfsfp);
 702 error_free:
 703         free(temp);
 704         return ret;
 705 }
 706
 707 #endif /* _IIO_UTILS_H */