tools/iio/iio_generic_buffer.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Industrialio buffer test code.
   3  *
   4  * Copyright (c) 2008 Jonathan Cameron
   5  *
   6  * This program is primarily intended as an example application.
   7  * Reads the current buffer setup from sysfs and starts a short capture
   8  * from the specified device, pretty printing the result after appropriate
   9  * conversion.
  10  *
  11  * Command line parameters
  12  * generic_buffer -n <device_name> -t <trigger_name>
  13  * If trigger name is not specified the program assumes you want a dataready
  14  * trigger associated with the device and goes looking for it.
  15  */
  16
  17 #include <unistd.h>
  18 #include <stdlib.h>
  19 #include <dirent.h>
  20 #include <fcntl.h>
  21 #include <stdio.h>
  22 #include <errno.h>
  23 #include <sys/stat.h>
  24 #include <sys/dir.h>
  25 #include <linux/types.h>
  26 #include <string.h>
  27 #include <poll.h>
  28 #include <endian.h>
  29 #include <getopt.h>
  30 #include <inttypes.h>
  31 #include <stdbool.h>
  32 #include <signal.h>
  33 #include "iio_utils.h"
  34
  35 /**
  36  * enum autochan - state for the automatic channel enabling mechanism
  37  */
  38 enum autochan {
  39         AUTOCHANNELS_DISABLED,
  40         AUTOCHANNELS_ENABLED,
  41         AUTOCHANNELS_ACTIVE,
  42 };
  43
  44 /**
  45  * size_from_channelarray() - calculate the storage size of a scan
  46  * @channels:           the channel info array
  47  * @num_channels:       number of channels
  48  *
  49  * Has the side effect of filling the channels[i].location values used
  50  * in processing the buffer output.
  51  **/
  52 static unsigned int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
  53 {
  54         unsigned int bytes = 0;
  55         int i = 0, max = 0;
  56         unsigned int misalignment;
  57
  58         while (i < num_channels) {
  59                 if (channels[i].bytes > max)
  60                         max = channels[i].bytes;
  61                 if (bytes % channels[i].bytes == 0)
  62                         channels[i].location = bytes;
  63                 else
  64                         channels[i].location = bytes - bytes % channels[i].bytes
  65                                                + channels[i].bytes;
  66
  67                 bytes = channels[i].location + channels[i].bytes;
  68                 i++;
  69         }
  70         /*
  71          * We want the data in next sample to also be properly aligned so
  72          * we'll add padding at the end if needed. Adding padding only
  73          * works for channel data which size is 2^n bytes.
  74          */
  75         misalignment = bytes % max;
  76         if (misalignment)
  77                 bytes += max - misalignment;
  78
  79         return bytes;
  80 }
  81
  82 static void print1byte(uint8_t input, struct iio_channel_info *info)
  83 {
  84         /*
  85          * Shift before conversion to avoid sign extension
  86          * of left aligned data
  87          */
  88         input >>= info->shift;
  89         input &= info->mask;
  90         if (info->is_signed) {
  91                 int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
  92                              (8 - info->bits_used);
  93                 printf("%05f ", ((float)val + info->offset) * info->scale);
  94         } else {
  95                 printf("%05f ", ((float)input + info->offset) * info->scale);
  96         }
  97 }
  98
  99 static void print2byte(uint16_t input, struct iio_channel_info *info)
 100 {
 101         /* First swap if incorrect endian */
 102         if (info->be)
 103                 input = be16toh(input);
 104         else
 105                 input = le16toh(input);
 106
 107         /*
 108          * Shift before conversion to avoid sign extension
 109          * of left aligned data
 110          */
 111         input >>= info->shift;
 112         input &= info->mask;
 113         if (info->is_signed) {
 114                 int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
 115                               (16 - info->bits_used);
 116                 printf("%05f ", ((float)val + info->offset) * info->scale);
 117         } else {
 118                 printf("%05f ", ((float)input + info->offset) * info->scale);
 119         }
 120 }
 121
 122 static void print4byte(uint32_t input, struct iio_channel_info *info)
 123 {
 124         /* First swap if incorrect endian */
 125         if (info->be)
 126                 input = be32toh(input);
 127         else
 128                 input = le32toh(input);
 129
 130         /*
 131          * Shift before conversion to avoid sign extension
 132          * of left aligned data
 133          */
 134         input >>= info->shift;
 135         input &= info->mask;
 136         if (info->is_signed) {
 137                 int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
 138                               (32 - info->bits_used);
 139                 printf("%05f ", ((float)val + info->offset) * info->scale);
 140         } else {
 141                 printf("%05f ", ((float)input + info->offset) * info->scale);
 142         }
 143 }
 144
 145 static void print8byte(uint64_t input, struct iio_channel_info *info)
 146 {
 147         /* First swap if incorrect endian */
 148         if (info->be)
 149                 input = be64toh(input);
 150         else
 151                 input = le64toh(input);
 152
 153         /*
 154          * Shift before conversion to avoid sign extension
 155          * of left aligned data
 156          */
 157         input >>= info->shift;
 158         input &= info->mask;
 159         if (info->is_signed) {
 160                 int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
 161                               (64 - info->bits_used);
 162                 /* special case for timestamp */
 163                 if (info->scale == 1.0f && info->offset == 0.0f)
 164                         printf("%" PRId64 " ", val);
 165                 else
 166                         printf("%05f ",
 167                                ((float)val + info->offset) * info->scale);
 168         } else {
 169                 printf("%05f ", ((float)input + info->offset) * info->scale);
 170         }
 171 }
 172
 173 /**
 174  * process_scan() - print out the values in SI units
 175  * @data:               pointer to the start of the scan
 176  * @channels:           information about the channels.
 177  *                      Note: size_from_channelarray must have been called first
 178  *                            to fill the location offsets.
 179  * @num_channels:       number of channels
 180  **/
 181 static void process_scan(char *data, struct iio_channel_info *channels,
 182                          int num_channels)
 183 {
 184         int k;
 185
 186         for (k = 0; k < num_channels; k++)
 187                 switch (channels[k].bytes) {
 188                         /* only a few cases implemented so far */
 189                 case 1:
 190                         print1byte(*(uint8_t *)(data + channels[k].location),
 191                                    &channels[k]);
 192                         break;
 193                 case 2:
 194                         print2byte(*(uint16_t *)(data + channels[k].location),
 195                                    &channels[k]);
 196                         break;
 197                 case 4:
 198                         print4byte(*(uint32_t *)(data + channels[k].location),
 199                                    &channels[k]);
 200                         break;
 201                 case 8:
 202                         print8byte(*(uint64_t *)(data + channels[k].location),
 203                                    &channels[k]);
 204                         break;
 205                 default:
 206                         break;
 207                 }
 208         printf("\n");
 209 }
 210
 211 static int enable_disable_all_channels(char *dev_dir_name, int enable)
 212 {
 213         const struct dirent *ent;
 214         char scanelemdir[256];
 215         DIR *dp;
 216         int ret;
 217
 218         snprintf(scanelemdir, sizeof(scanelemdir),
 219                  FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name);
 220         scanelemdir[sizeof(scanelemdir)-1] = '\0';
 221
 222         dp = opendir(scanelemdir);
 223         if (!dp) {
 224                 fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
 225                         scanelemdir);
 226                 return -EIO;
 227         }
 228
 229         ret = -ENOENT;
 230         while (ent = readdir(dp), ent) {
 231                 if (iioutils_check_suffix(ent->d_name, "_en")) {
 232                         printf("%sabling: %s\n",
 233                                enable ? "En" : "Dis",
 234                                ent->d_name);
 235                         ret = write_sysfs_int(ent->d_name, scanelemdir,
 236                                               enable);
 237                         if (ret < 0)
 238                                 fprintf(stderr, "Failed to enable/disable %s\n",
 239                                         ent->d_name);
 240                 }
 241         }
 242
 243         if (closedir(dp) == -1) {
 244                 perror("Enabling/disabling channels: "
 245                        "Failed to close directory");
 246                 return -errno;
 247         }
 248         return 0;
 249 }
 250
 251 static void print_usage(void)
 252 {
 253         fprintf(stderr, "Usage: generic_buffer [options]...\n"
 254                 "Capture, convert and output data from IIO device buffer\n"
 255                 "  -a         Auto-activate all available channels\n"
 256                 "  -A         Force-activate ALL channels\n"
 257                 "  -c <n>     Do n conversions, or loop forever if n < 0\n"
 258                 "  -e         Disable wait for event (new data)\n"
 259                 "  -g         Use trigger-less mode\n"
 260                 "  -l <n>     Set buffer length to n samples\n"
 261                 "  --device-name -n <name>\n"
 262                 "  --device-num -N <num>\n"
 263                 "        Set device by name or number (mandatory)\n"
 264                 "  --trigger-name -t <name>\n"
 265                 "  --trigger-num -T <num>\n"
 266                 "        Set trigger by name or number\n"
 267                 "  -w <n>     Set delay between reads in us (event-less mode)\n");
 268 }
 269
 270 static enum autochan autochannels = AUTOCHANNELS_DISABLED;
 271 static char *dev_dir_name = NULL;
 272 static char *buf_dir_name = NULL;
 273 static bool current_trigger_set = false;
 274
 275 static void cleanup(void)
 276 {
 277         int ret;
 278
 279         /* Disable trigger */
 280         if (dev_dir_name && current_trigger_set) {
 281                 /* Disconnect the trigger - just write a dummy name. */
 282                 ret = write_sysfs_string("trigger/current_trigger",
 283                                          dev_dir_name, "NULL");
 284                 if (ret < 0)
 285                         fprintf(stderr, "Failed to disable trigger: %s\n",
 286                                 strerror(-ret));
 287                 current_trigger_set = false;
 288         }
 289
 290         /* Disable buffer */
 291         if (buf_dir_name) {
 292                 ret = write_sysfs_int("enable", buf_dir_name, 0);
 293                 if (ret < 0)
 294                         fprintf(stderr, "Failed to disable buffer: %s\n",
 295                                 strerror(-ret));
 296         }
 297
 298         /* Disable channels if auto-enabled */
 299         if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
 300                 ret = enable_disable_all_channels(dev_dir_name, 0);
 301                 if (ret)
 302                         fprintf(stderr, "Failed to disable all channels\n");
 303                 autochannels = AUTOCHANNELS_DISABLED;
 304         }
 305 }
 306
 307 static void sig_handler(int signum)
 308 {
 309         fprintf(stderr, "Caught signal %d\n", signum);
 310         cleanup();
 311         exit(-signum);
 312 }
 313
 314 static void register_cleanup(void)
 315 {
 316         struct sigaction sa = { .sa_handler = sig_handler };
 317         const int signums[] = { SIGINT, SIGTERM, SIGABRT };
 318         int ret, i;
 319
 320         for (i = 0; i < ARRAY_SIZE(signums); ++i) {
 321                 ret = sigaction(signums[i], &sa, NULL);
 322                 if (ret) {
 323                         perror("Failed to register signal handler");
 324                         exit(-1);
 325                 }
 326         }
 327 }
 328
 329 static const struct option longopts[] = {
 330         { "device-name",        1, 0, 'n' },
 331         { "device-num",         1, 0, 'N' },
 332         { "trigger-name",       1, 0, 't' },
 333         { "trigger-num",        1, 0, 'T' },
 334         { },
 335 };
 336
 337 int main(int argc, char **argv)
 338 {
 339         long long num_loops = 2;
 340         unsigned long timedelay = 1000000;
 341         unsigned long buf_len = 128;
 342
 343         ssize_t i;
 344         unsigned long long j;
 345         unsigned long toread;
 346         int ret, c;
 347         int fp = -1;
 348
 349         int num_channels = 0;
 350         char *trigger_name = NULL, *device_name = NULL;
 351
 352         char *data = NULL;
 353         ssize_t read_size;
 354         int dev_num = -1, trig_num = -1;
 355         char *buffer_access = NULL;
 356         unsigned int scan_size;
 357         int noevents = 0;
 358         int notrigger = 0;
 359         char *dummy;
 360         bool force_autochannels = false;
 361
 362         struct iio_channel_info *channels = NULL;
 363
 364         register_cleanup();
 365
 366         while ((c = getopt_long(argc, argv, "aAc:egl:n:N:t:T:w:?", longopts,
 367                                 NULL)) != -1) {
 368                 switch (c) {
 369                 case 'a':
 370                         autochannels = AUTOCHANNELS_ENABLED;
 371                         break;
 372                 case 'A':
 373                         autochannels = AUTOCHANNELS_ENABLED;
 374                         force_autochannels = true;
 375                         break;
 376                 case 'c':
 377                         errno = 0;
 378                         num_loops = strtoll(optarg, &dummy, 10);
 379                         if (errno) {
 380                                 ret = -errno;
 381                                 goto error;
 382                         }
 383
 384                         break;
 385                 case 'e':
 386                         noevents = 1;
 387                         break;
 388                 case 'g':
 389                         notrigger = 1;
 390                         break;
 391                 case 'l':
 392                         errno = 0;
 393                         buf_len = strtoul(optarg, &dummy, 10);
 394                         if (errno) {
 395                                 ret = -errno;
 396                                 goto error;
 397                         }
 398
 399                         break;
 400                 case 'n':
 401                         device_name = strdup(optarg);
 402                         break;
 403                 case 'N':
 404                         errno = 0;
 405                         dev_num = strtoul(optarg, &dummy, 10);
 406                         if (errno) {
 407                                 ret = -errno;
 408                                 goto error;
 409                         }
 410                         break;
 411                 case 't':
 412                         trigger_name = strdup(optarg);
 413                         break;
 414                 case 'T':
 415                         errno = 0;
 416                         trig_num = strtoul(optarg, &dummy, 10);
 417                         if (errno)
 418                                 return -errno;
 419                         break;
 420                 case 'w':
 421                         errno = 0;
 422                         timedelay = strtoul(optarg, &dummy, 10);
 423                         if (errno) {
 424                                 ret = -errno;
 425                                 goto error;
 426                         }
 427                         break;
 428                 case '?':
 429                         print_usage();
 430                         ret = -1;
 431                         goto error;
 432                 }
 433         }
 434
 435         /* Find the device requested */
 436         if (dev_num < 0 && !device_name) {
 437                 fprintf(stderr, "Device not set\n");
 438                 print_usage();
 439                 ret = -1;
 440                 goto error;
 441         } else if (dev_num >= 0 && device_name) {
 442                 fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
 443                 print_usage();
 444                 ret = -1;
 445                 goto error;
 446         } else if (dev_num < 0) {
 447                 dev_num = find_type_by_name(device_name, "iio:device");
 448                 if (dev_num < 0) {
 449                         fprintf(stderr, "Failed to find the %s\n", device_name);
 450                         ret = dev_num;
 451                         goto error;
 452                 }
 453         }
 454         printf("iio device number being used is %d\n", dev_num);
 455
 456         ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
 457         if (ret < 0)
 458                 return -ENOMEM;
 459         /* Fetch device_name if specified by number */
 460         if (!device_name) {
 461                 device_name = malloc(IIO_MAX_NAME_LENGTH);
 462                 if (!device_name) {
 463                         ret = -ENOMEM;
 464                         goto error;
 465                 }
 466                 ret = read_sysfs_string("name", dev_dir_name, device_name);
 467                 if (ret < 0) {
 468                         fprintf(stderr, "Failed to read name of device %d\n", dev_num);
 469                         goto error;
 470                 }
 471         }
 472
 473         if (notrigger) {
 474                 printf("trigger-less mode selected\n");
 475         } else if (trig_num >= 0) {
 476                 char *trig_dev_name;
 477                 ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
 478                 if (ret < 0) {
 479                         return -ENOMEM;
 480                 }
 481                 trigger_name = malloc(IIO_MAX_NAME_LENGTH);
 482                 ret = read_sysfs_string("name", trig_dev_name, trigger_name);
 483                 free(trig_dev_name);
 484                 if (ret < 0) {
 485                         fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
 486                         return ret;
 487                 }
 488                 printf("iio trigger number being used is %d\n", trig_num);
 489         } else {
 490                 if (!trigger_name) {
 491                         /*
 492                          * Build the trigger name. If it is device associated
 493                          * its name is <device_name>_dev[n] where n matches
 494                          * the device number found above.
 495                          */
 496                         ret = asprintf(&trigger_name,
 497                                        "%s-dev%d", device_name, dev_num);
 498                         if (ret < 0) {
 499                                 ret = -ENOMEM;
 500                                 goto error;
 501                         }
 502                 }
 503
 504                 /* Look for this "-devN" trigger */
 505                 trig_num = find_type_by_name(trigger_name, "trigger");
 506                 if (trig_num < 0) {
 507                         /* OK try the simpler "-trigger" suffix instead */
 508                         free(trigger_name);
 509                         ret = asprintf(&trigger_name,
 510                                        "%s-trigger", device_name);
 511                         if (ret < 0) {
 512                                 ret = -ENOMEM;
 513                                 goto error;
 514                         }
 515                 }
 516
 517                 trig_num = find_type_by_name(trigger_name, "trigger");
 518                 if (trig_num < 0) {
 519                         fprintf(stderr, "Failed to find the trigger %s\n",
 520                                 trigger_name);
 521                         ret = trig_num;
 522                         goto error;
 523                 }
 524
 525                 printf("iio trigger number being used is %d\n", trig_num);
 526         }
 527
 528         /*
 529          * Parse the files in scan_elements to identify what channels are
 530          * present
 531          */
 532         ret = build_channel_array(dev_dir_name, &channels, &num_channels);
 533         if (ret) {
 534                 fprintf(stderr, "Problem reading scan element information\n"
 535                         "diag %s\n", dev_dir_name);
 536                 goto error;
 537         }
 538         if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&
 539             !force_autochannels) {
 540                 fprintf(stderr, "Auto-channels selected but some channels "
 541                         "are already activated in sysfs\n");
 542                 fprintf(stderr, "Proceeding without activating any channels\n");
 543         }
 544
 545         if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||
 546             (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {
 547                 fprintf(stderr, "Enabling all channels\n");
 548
 549                 ret = enable_disable_all_channels(dev_dir_name, 1);
 550                 if (ret) {
 551                         fprintf(stderr, "Failed to enable all channels\n");
 552                         goto error;
 553                 }
 554
 555                 /* This flags that we need to disable the channels again */
 556                 autochannels = AUTOCHANNELS_ACTIVE;
 557
 558                 ret = build_channel_array(dev_dir_name, &channels,
 559                                           &num_channels);
 560                 if (ret) {
 561                         fprintf(stderr, "Problem reading scan element "
 562                                 "information\n"
 563                                 "diag %s\n", dev_dir_name);
 564                         goto error;
 565                 }
 566                 if (!num_channels) {
 567                         fprintf(stderr, "Still no channels after "
 568                                 "auto-enabling, giving up\n");
 569                         goto error;
 570                 }
 571         }
 572
 573         if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
 574                 fprintf(stderr,
 575                         "No channels are enabled, we have nothing to scan.\n");
 576                 fprintf(stderr, "Enable channels manually in "
 577                         FORMAT_SCAN_ELEMENTS_DIR
 578                         "/*_en or pass -a to autoenable channels and "
 579                         "try again.\n", dev_dir_name);
 580                 ret = -ENOENT;
 581                 goto error;
 582         }
 583
 584         /*
 585          * Construct the directory name for the associated buffer.
 586          * As we know that the lis3l02dq has only one buffer this may
 587          * be built rather than found.
 588          */
 589         ret = asprintf(&buf_dir_name,
 590                        "%siio:device%d/buffer", iio_dir, dev_num);
 591         if (ret < 0) {
 592                 ret = -ENOMEM;
 593                 goto error;
 594         }
 595
 596         if (!notrigger) {
 597                 printf("%s %s\n", dev_dir_name, trigger_name);
 598                 /*
 599                  * Set the device trigger to be the data ready trigger found
 600                  * above
 601                  */
 602                 ret = write_sysfs_string_and_verify("trigger/current_trigger",
 603                                                     dev_dir_name,
 604                                                     trigger_name);
 605                 if (ret < 0) {
 606                         fprintf(stderr,
 607                                 "Failed to write current_trigger file\n");
 608                         goto error;
 609                 }
 610         }
 611
 612         /* Setup ring buffer parameters */
 613         ret = write_sysfs_int("length", buf_dir_name, buf_len);
 614         if (ret < 0)
 615                 goto error;
 616
 617         /* Enable the buffer */
 618         ret = write_sysfs_int("enable", buf_dir_name, 1);
 619         if (ret < 0) {
 620                 fprintf(stderr,
 621                         "Failed to enable buffer: %s\n", strerror(-ret));
 622                 goto error;
 623         }
 624
 625         scan_size = size_from_channelarray(channels, num_channels);
 626
 627         size_t total_buf_len = scan_size * buf_len;
 628
 629         if (scan_size > 0 && total_buf_len / scan_size != buf_len) {
 630                 ret = -EFAULT;
 631                 perror("Integer overflow happened when calculate scan_size * buf_len");
 632                 goto error;
 633         }
 634
 635         data = malloc(total_buf_len);
 636         if (!data) {
 637                 ret = -ENOMEM;
 638                 goto error;
 639         }
 640
 641         ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
 642         if (ret < 0) {
 643                 ret = -ENOMEM;
 644                 goto error;
 645         }
 646
 647         /* Attempt to open non blocking the access dev */
 648         fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
 649         if (fp == -1) { /* TODO: If it isn't there make the node */
 650                 ret = -errno;
 651                 fprintf(stderr, "Failed to open %s\n", buffer_access);
 652                 goto error;
 653         }
 654
 655         for (j = 0; j < num_loops || num_loops < 0; j++) {
 656                 if (!noevents) {
 657                         struct pollfd pfd = {
 658                                 .fd = fp,
 659                                 .events = POLLIN,
 660                         };
 661
 662                         ret = poll(&pfd, 1, -1);
 663                         if (ret < 0) {
 664                                 ret = -errno;
 665                                 goto error;
 666                         } else if (ret == 0) {
 667                                 continue;
 668                         }
 669
 670                         toread = buf_len;
 671                 } else {
 672                         usleep(timedelay);
 673                         toread = 64;
 674                 }
 675
 676                 read_size = read(fp, data, toread * scan_size);
 677                 if (read_size < 0) {
 678                         if (errno == EAGAIN) {
 679                                 fprintf(stderr, "nothing available\n");
 680                                 continue;
 681                         } else {
 682                                 break;
 683                         }
 684                 }
 685                 for (i = 0; i < read_size / scan_size; i++)
 686                         process_scan(data + scan_size * i, channels,
 687                                      num_channels);
 688         }
 689
 690 error:
 691         cleanup();
 692
 693         if (fp >= 0 && close(fp) == -1)
 694                 perror("Failed to close buffer");
 695         free(buffer_access);
 696         free(data);
 697         free(buf_dir_name);
 698         for (i = num_channels - 1; i >= 0; i--) {
 699                 free(channels[i].name);
 700                 free(channels[i].generic_name);
 701         }
 702         free(channels);
 703         free(trigger_name);
 704         free(device_name);
 705         free(dev_dir_name);
 706
 707         return ret;
 708 }