kernel/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         /* reorder so that the array is in index order */
 407         bsort_channel_array_by_index(ci_array, *counter);
 408
 409         return 0;
 410
 411 error_cleanup_array:
 412         for (i = count - 1;  i >= 0; i--)
 413                 free((*ci_array)[i].name);
 414         free(*ci_array);
 415 error_close_dir:
 416         closedir(dp);
 417 error_free_name:
 418         free(scan_el_dir);
 419 error_ret:
 420         return ret;
 421 }
 422
 423 /**
 424  * find_type_by_name() - function to match top level types by name
 425  * @name: top level type instance name
 426  * @type: the type of top level instance being sort
 427  *
 428  * Typical types this is used for are device and trigger.
 429  **/
 430 int find_type_by_name(const char *name, const char *type)
 431 {
 432         const struct dirent *ent;
 433         int number, numstrlen;
 434
 435         FILE *nameFile;
 436         DIR *dp;
 437         char thisname[IIO_MAX_NAME_LENGTH];
 438         char *filename;
 439
 440         dp = opendir(iio_dir);
 441         if (dp == NULL) {
 442                 printf("No industrialio devices available\n");
 443                 return -ENODEV;
 444         }
 445
 446         while (ent = readdir(dp), ent != NULL) {
 447                 if (strcmp(ent->d_name, ".") != 0 &&
 448                         strcmp(ent->d_name, "..") != 0 &&
 449                         strlen(ent->d_name) > strlen(type) &&
 450                         strncmp(ent->d_name, type, strlen(type)) == 0) {
 451                         numstrlen = sscanf(ent->d_name + strlen(type),
 452                                            "%d",
 453                                            &number);
 454                         /* verify the next character is not a colon */
 455                         if (strncmp(ent->d_name + strlen(type) + numstrlen,
 456                                         ":",
 457                                         1) != 0) {
 458                                 filename = malloc(strlen(iio_dir)
 459                                                 + strlen(type)
 460                                                 + numstrlen
 461                                                 + 6);
 462                                 if (filename == NULL) {
 463                                         closedir(dp);
 464                                         return -ENOMEM;
 465                                 }
 466                                 sprintf(filename, "%s%s%d/name",
 467                                         iio_dir,
 468                                         type,
 469                                         number);
 470                                 nameFile = fopen(filename, "r");
 471                                 if (!nameFile) {
 472                                         free(filename);
 473                                         continue;
 474                                 }
 475                                 free(filename);
 476                                 fscanf(nameFile, "%s", thisname);
 477                                 fclose(nameFile);
 478                                 if (strcmp(name, thisname) == 0) {
 479                                         closedir(dp);
 480                                         return number;
 481                                 }
 482                         }
 483                 }
 484         }
 485         closedir(dp);
 486         return -ENODEV;
 487 }
 488
 489 int _write_sysfs_int(char *filename, char *basedir, int val, int verify)
 490 {
 491         int ret = 0;
 492         FILE *sysfsfp;
 493         int test;
 494         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 495
 496         if (temp == NULL)
 497                 return -ENOMEM;
 498         sprintf(temp, "%s/%s", basedir, filename);
 499         sysfsfp = fopen(temp, "w");
 500         if (sysfsfp == NULL) {
 501                 printf("failed to open %s\n", temp);
 502                 ret = -errno;
 503                 goto error_free;
 504         }
 505         fprintf(sysfsfp, "%d", val);
 506         fclose(sysfsfp);
 507         if (verify) {
 508                 sysfsfp = fopen(temp, "r");
 509                 if (sysfsfp == NULL) {
 510                         printf("failed to open %s\n", temp);
 511                         ret = -errno;
 512                         goto error_free;
 513                 }
 514                 fscanf(sysfsfp, "%d", &test);
 515                 fclose(sysfsfp);
 516                 if (test != val) {
 517                         printf("Possible failure in int write %d to %s%s\n",
 518                                 val,
 519                                 basedir,
 520                                 filename);
 521                         ret = -1;
 522                 }
 523         }
 524 error_free:
 525         free(temp);
 526         return ret;
 527 }
 528
 529 int write_sysfs_int(char *filename, char *basedir, int val)
 530 {
 531         return _write_sysfs_int(filename, basedir, val, 0);
 532 }
 533
 534 int write_sysfs_int_and_verify(char *filename, char *basedir, int val)
 535 {
 536         return _write_sysfs_int(filename, basedir, val, 1);
 537 }
 538
 539 int _write_sysfs_string(char *filename, char *basedir, char *val, int verify)
 540 {
 541         int ret = 0;
 542         FILE  *sysfsfp;
 543         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 544
 545         if (temp == NULL) {
 546                 printf("Memory allocation failed\n");
 547                 return -ENOMEM;
 548         }
 549         sprintf(temp, "%s/%s", basedir, filename);
 550         sysfsfp = fopen(temp, "w");
 551         if (sysfsfp == NULL) {
 552                 printf("Could not open %s\n", temp);
 553                 ret = -errno;
 554                 goto error_free;
 555         }
 556         fprintf(sysfsfp, "%s", val);
 557         fclose(sysfsfp);
 558         if (verify) {
 559                 sysfsfp = fopen(temp, "r");
 560                 if (sysfsfp == NULL) {
 561                         printf("could not open file to verify\n");
 562                         ret = -errno;
 563                         goto error_free;
 564                 }
 565                 fscanf(sysfsfp, "%s", temp);
 566                 fclose(sysfsfp);
 567                 if (strcmp(temp, val) != 0) {
 568                         printf("Possible failure in string write of %s "
 569                                 "Should be %s "
 570                                 "written to %s\%s\n",
 571                                 temp,
 572                                 val,
 573                                 basedir,
 574                                 filename);
 575                         ret = -1;
 576                 }
 577         }
 578 error_free:
 579         free(temp);
 580
 581         return ret;
 582 }
 583
 584 /**
 585  * write_sysfs_string_and_verify() - string write, readback and verify
 586  * @filename: name of file to write to
 587  * @basedir: the sysfs directory in which the file is to be found
 588  * @val: the string to write
 589  **/
 590 int write_sysfs_string_and_verify(char *filename, char *basedir, char *val)
 591 {
 592         return _write_sysfs_string(filename, basedir, val, 1);
 593 }
 594
 595 int write_sysfs_string(char *filename, char *basedir, char *val)
 596 {
 597         return _write_sysfs_string(filename, basedir, val, 0);
 598 }
 599
 600 int read_sysfs_posint(char *filename, char *basedir)
 601 {
 602         int ret;
 603         FILE  *sysfsfp;
 604         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 605
 606         if (temp == NULL) {
 607                 printf("Memory allocation failed");
 608                 return -ENOMEM;
 609         }
 610         sprintf(temp, "%s/%s", basedir, filename);
 611         sysfsfp = fopen(temp, "r");
 612         if (sysfsfp == NULL) {
 613                 ret = -errno;
 614                 goto error_free;
 615         }
 616         fscanf(sysfsfp, "%d\n", &ret);
 617         fclose(sysfsfp);
 618 error_free:
 619         free(temp);
 620         return ret;
 621 }
 622
 623 int read_sysfs_float(char *filename, char *basedir, float *val)
 624 {
 625         int ret = 0;
 626         FILE  *sysfsfp;
 627         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 628
 629         if (temp == NULL) {
 630                 printf("Memory allocation failed");
 631                 return -ENOMEM;
 632         }
 633         sprintf(temp, "%s/%s", basedir, filename);
 634         sysfsfp = fopen(temp, "r");
 635         if (sysfsfp == NULL) {
 636                 ret = -errno;
 637                 goto error_free;
 638         }
 639         fscanf(sysfsfp, "%f\n", val);
 640         fclose(sysfsfp);
 641 error_free:
 642         free(temp);
 643         return ret;
 644 }
 645
 646 int read_sysfs_string(const char *filename, const char *basedir, char *str)
 647 {
 648         int ret = 0;
 649         FILE  *sysfsfp;
 650         char *temp = malloc(strlen(basedir) + strlen(filename) + 2);
 651
 652         if (temp == NULL) {
 653                 printf("Memory allocation failed");
 654                 return -ENOMEM;
 655         }
 656         sprintf(temp, "%s/%s", basedir, filename);
 657         sysfsfp = fopen(temp, "r");
 658         if (sysfsfp == NULL) {
 659                 ret = -errno;
 660                 goto error_free;
 661         }
 662         fscanf(sysfsfp, "%s\n", str);
 663         fclose(sysfsfp);
 664 error_free:
 665         free(temp);
 666         return ret;
 667 }
 668
 669 #endif /* _IIO_UTILS_H */