tools/iio/iio_generic_buffer.c

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