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                 "  -c <n>     Do n conversions\n"
 251                 "  -e         Disable wait for event (new data)\n"
 252                 "  -g         Use trigger-less mode\n"
 253                 "  -l <n>     Set buffer length to n samples\n"
 254                 "  --device-name -n <name>\n"
 255                 "  --device-num -N <num>\n"
 256                 "        Set device by name or number (mandatory)\n"
 257                 "  --trigger-name -t <name>\n"
 258                 "  --trigger-num -T <num>\n"
 259                 "        Set trigger by name or number\n"
 260                 "  -w <n>     Set delay between reads in us (event-less mode)\n");
 261 }
 262
 263 enum autochan autochannels = AUTOCHANNELS_DISABLED;
 264 char *dev_dir_name = NULL;
 265 char *buf_dir_name = NULL;
 266 bool current_trigger_set = false;
 267
 268 void cleanup(void)
 269 {
 270         int ret;
 271
 272         /* Disable trigger */
 273         if (dev_dir_name && current_trigger_set) {
 274                 /* Disconnect the trigger - just write a dummy name. */
 275                 ret = write_sysfs_string("trigger/current_trigger",
 276                                          dev_dir_name, "NULL");
 277                 if (ret < 0)
 278                         fprintf(stderr, "Failed to disable trigger: %s\n",
 279                                 strerror(-ret));
 280                 current_trigger_set = false;
 281         }
 282
 283         /* Disable buffer */
 284         if (buf_dir_name) {
 285                 ret = write_sysfs_int("enable", buf_dir_name, 0);
 286                 if (ret < 0)
 287                         fprintf(stderr, "Failed to disable buffer: %s\n",
 288                                 strerror(-ret));
 289         }
 290
 291         /* Disable channels if auto-enabled */
 292         if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
 293                 ret = enable_disable_all_channels(dev_dir_name, 0);
 294                 if (ret)
 295                         fprintf(stderr, "Failed to disable all channels\n");
 296                 autochannels = AUTOCHANNELS_DISABLED;
 297         }
 298 }
 299
 300 void sig_handler(int signum)
 301 {
 302         fprintf(stderr, "Caught signal %d\n", signum);
 303         cleanup();
 304         exit(-signum);
 305 }
 306
 307 void register_cleanup(void)
 308 {
 309         struct sigaction sa = { .sa_handler = sig_handler };
 310         const int signums[] = { SIGINT, SIGTERM, SIGABRT };
 311         int ret, i;
 312
 313         for (i = 0; i < ARRAY_SIZE(signums); ++i) {
 314                 ret = sigaction(signums[i], &sa, NULL);
 315                 if (ret) {
 316                         perror("Failed to register signal handler");
 317                         exit(-1);
 318                 }
 319         }
 320 }
 321
 322 static const struct option longopts[] = {
 323         { "device-name",        1, 0, 'n' },
 324         { "device-num",         1, 0, 'N' },
 325         { "trigger-name",       1, 0, 't' },
 326         { "trigger-num",        1, 0, 'T' },
 327         { },
 328 };
 329
 330 int main(int argc, char **argv)
 331 {
 332         unsigned long num_loops = 2;
 333         unsigned long timedelay = 1000000;
 334         unsigned long buf_len = 128;
 335
 336         int ret, c, i, j, toread;
 337         int fp = -1;
 338
 339         int num_channels = 0;
 340         char *trigger_name = NULL, *device_name = NULL;
 341
 342         char *data = NULL;
 343         ssize_t read_size;
 344         int dev_num = -1, trig_num = -1;
 345         char *buffer_access = NULL;
 346         int scan_size;
 347         int noevents = 0;
 348         int notrigger = 0;
 349         char *dummy;
 350
 351         struct iio_channel_info *channels = NULL;
 352
 353         register_cleanup();
 354
 355         while ((c = getopt_long(argc, argv, "ac:egl:n:N:t:T:w:", longopts, NULL)) != -1) {
 356                 switch (c) {
 357                 case 'a':
 358                         autochannels = AUTOCHANNELS_ENABLED;
 359                         break;
 360                 case 'c':
 361                         errno = 0;
 362                         num_loops = strtoul(optarg, &dummy, 10);
 363                         if (errno) {
 364                                 ret = -errno;
 365                                 goto error;
 366                         }
 367
 368                         break;
 369                 case 'e':
 370                         noevents = 1;
 371                         break;
 372                 case 'g':
 373                         notrigger = 1;
 374                         break;
 375                 case 'l':
 376                         errno = 0;
 377                         buf_len = strtoul(optarg, &dummy, 10);
 378                         if (errno) {
 379                                 ret = -errno;
 380                                 goto error;
 381                         }
 382
 383                         break;
 384                 case 'n':
 385                         device_name = strdup(optarg);
 386                         break;
 387                 case 'N':
 388                         errno = 0;
 389                         dev_num = strtoul(optarg, &dummy, 10);
 390                         if (errno) {
 391                                 ret = -errno;
 392                                 goto error;
 393                         }
 394                         break;
 395                 case 't':
 396                         trigger_name = strdup(optarg);
 397                         break;
 398                 case 'T':
 399                         errno = 0;
 400                         trig_num = strtoul(optarg, &dummy, 10);
 401                         if (errno)
 402                                 return -errno;
 403                         break;
 404                 case 'w':
 405                         errno = 0;
 406                         timedelay = strtoul(optarg, &dummy, 10);
 407                         if (errno) {
 408                                 ret = -errno;
 409                                 goto error;
 410                         }
 411                         break;
 412                 case '?':
 413                         print_usage();
 414                         ret = -1;
 415                         goto error;
 416                 }
 417         }
 418
 419         /* Find the device requested */
 420         if (dev_num < 0 && !device_name) {
 421                 fprintf(stderr, "Device not set\n");
 422                 print_usage();
 423                 ret = -1;
 424                 goto error;
 425         } else if (dev_num >= 0 && device_name) {
 426                 fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
 427                 print_usage();
 428                 ret = -1;
 429                 goto error;
 430         } else if (dev_num < 0) {
 431                 dev_num = find_type_by_name(device_name, "iio:device");
 432                 if (dev_num < 0) {
 433                         fprintf(stderr, "Failed to find the %s\n", device_name);
 434                         ret = dev_num;
 435                         goto error;
 436                 }
 437         }
 438         printf("iio device number being used is %d\n", dev_num);
 439
 440         ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
 441         if (ret < 0)
 442                 return -ENOMEM;
 443         /* Fetch device_name if specified by number */
 444         if (!device_name) {
 445                 device_name = malloc(IIO_MAX_NAME_LENGTH);
 446                 if (!device_name) {
 447                         ret = -ENOMEM;
 448                         goto error;
 449                 }
 450                 ret = read_sysfs_string("name", dev_dir_name, device_name);
 451                 if (ret < 0) {
 452                         fprintf(stderr, "Failed to read name of device %d\n", dev_num);
 453                         goto error;
 454                 }
 455         }
 456
 457         if (notrigger) {
 458                 printf("trigger-less mode selected\n");
 459         } else if (trig_num >= 0) {
 460                 char *trig_dev_name;
 461                 ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
 462                 if (ret < 0) {
 463                         return -ENOMEM;
 464                 }
 465                 trigger_name = malloc(IIO_MAX_NAME_LENGTH);
 466                 ret = read_sysfs_string("name", trig_dev_name, trigger_name);
 467                 free(trig_dev_name);
 468                 if (ret < 0) {
 469                         fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
 470                         return ret;
 471                 }
 472                 printf("iio trigger number being used is %d\n", trig_num);
 473         } else {
 474                 if (!trigger_name) {
 475                         /*
 476                          * Build the trigger name. If it is device associated
 477                          * its name is <device_name>_dev[n] where n matches
 478                          * the device number found above.
 479                          */
 480                         ret = asprintf(&trigger_name,
 481                                        "%s-dev%d", device_name, dev_num);
 482                         if (ret < 0) {
 483                                 ret = -ENOMEM;
 484                                 goto error;
 485                         }
 486                 }
 487
 488                 /* Look for this "-devN" trigger */
 489                 trig_num = find_type_by_name(trigger_name, "trigger");
 490                 if (trig_num < 0) {
 491                         /* OK try the simpler "-trigger" suffix instead */
 492                         free(trigger_name);
 493                         ret = asprintf(&trigger_name,
 494                                        "%s-trigger", device_name);
 495                         if (ret < 0) {
 496                                 ret = -ENOMEM;
 497                                 goto error;
 498                         }
 499                 }
 500
 501                 trig_num = find_type_by_name(trigger_name, "trigger");
 502                 if (trig_num < 0) {
 503                         fprintf(stderr, "Failed to find the trigger %s\n",
 504                                 trigger_name);
 505                         ret = trig_num;
 506                         goto error;
 507                 }
 508
 509                 printf("iio trigger number being used is %d\n", trig_num);
 510         }
 511
 512         /*
 513          * Parse the files in scan_elements to identify what channels are
 514          * present
 515          */
 516         ret = build_channel_array(dev_dir_name, &channels, &num_channels);
 517         if (ret) {
 518                 fprintf(stderr, "Problem reading scan element information\n"
 519                         "diag %s\n", dev_dir_name);
 520                 goto error;
 521         }
 522         if (num_channels && autochannels == AUTOCHANNELS_ENABLED) {
 523                 fprintf(stderr, "Auto-channels selected but some channels "
 524                         "are already activated in sysfs\n");
 525                 fprintf(stderr, "Proceeding without activating any channels\n");
 526         }
 527
 528         if (!num_channels && autochannels == AUTOCHANNELS_ENABLED) {
 529                 fprintf(stderr,
 530                         "No channels are enabled, enabling all channels\n");
 531
 532                 ret = enable_disable_all_channels(dev_dir_name, 1);
 533                 if (ret) {
 534                         fprintf(stderr, "Failed to enable all channels\n");
 535                         goto error;
 536                 }
 537
 538                 /* This flags that we need to disable the channels again */
 539                 autochannels = AUTOCHANNELS_ACTIVE;
 540
 541                 ret = build_channel_array(dev_dir_name, &channels,
 542                                           &num_channels);
 543                 if (ret) {
 544                         fprintf(stderr, "Problem reading scan element "
 545                                 "information\n"
 546                                 "diag %s\n", dev_dir_name);
 547                         goto error;
 548                 }
 549                 if (!num_channels) {
 550                         fprintf(stderr, "Still no channels after "
 551                                 "auto-enabling, giving up\n");
 552                         goto error;
 553                 }
 554         }
 555
 556         if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
 557                 fprintf(stderr,
 558                         "No channels are enabled, we have nothing to scan.\n");
 559                 fprintf(stderr, "Enable channels manually in "
 560                         FORMAT_SCAN_ELEMENTS_DIR
 561                         "/*_en or pass -a to autoenable channels and "
 562                         "try again.\n", dev_dir_name);
 563                 ret = -ENOENT;
 564                 goto error;
 565         }
 566
 567         /*
 568          * Construct the directory name for the associated buffer.
 569          * As we know that the lis3l02dq has only one buffer this may
 570          * be built rather than found.
 571          */
 572         ret = asprintf(&buf_dir_name,
 573                        "%siio:device%d/buffer", iio_dir, dev_num);
 574         if (ret < 0) {
 575                 ret = -ENOMEM;
 576                 goto error;
 577         }
 578
 579         if (!notrigger) {
 580                 printf("%s %s\n", dev_dir_name, trigger_name);
 581                 /*
 582                  * Set the device trigger to be the data ready trigger found
 583                  * above
 584                  */
 585                 ret = write_sysfs_string_and_verify("trigger/current_trigger",
 586                                                     dev_dir_name,
 587                                                     trigger_name);
 588                 if (ret < 0) {
 589                         fprintf(stderr,
 590                                 "Failed to write current_trigger file\n");
 591                         goto error;
 592                 }
 593         }
 594
 595         /* Setup ring buffer parameters */
 596         ret = write_sysfs_int("length", buf_dir_name, buf_len);
 597         if (ret < 0)
 598                 goto error;
 599
 600         /* Enable the buffer */
 601         ret = write_sysfs_int("enable", buf_dir_name, 1);
 602         if (ret < 0) {
 603                 fprintf(stderr,
 604                         "Failed to enable buffer: %s\n", strerror(-ret));
 605                 goto error;
 606         }
 607
 608         scan_size = size_from_channelarray(channels, num_channels);
 609         data = malloc(scan_size * buf_len);
 610         if (!data) {
 611                 ret = -ENOMEM;
 612                 goto error;
 613         }
 614
 615         ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
 616         if (ret < 0) {
 617                 ret = -ENOMEM;
 618                 goto error;
 619         }
 620
 621         /* Attempt to open non blocking the access dev */
 622         fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
 623         if (fp == -1) { /* TODO: If it isn't there make the node */
 624                 ret = -errno;
 625                 fprintf(stderr, "Failed to open %s\n", buffer_access);
 626                 goto error;
 627         }
 628
 629         for (j = 0; j < num_loops; j++) {
 630                 if (!noevents) {
 631                         struct pollfd pfd = {
 632                                 .fd = fp,
 633                                 .events = POLLIN,
 634                         };
 635
 636                         ret = poll(&pfd, 1, -1);
 637                         if (ret < 0) {
 638                                 ret = -errno;
 639                                 goto error;
 640                         } else if (ret == 0) {
 641                                 continue;
 642                         }
 643
 644                         toread = buf_len;
 645                 } else {
 646                         usleep(timedelay);
 647                         toread = 64;
 648                 }
 649
 650                 read_size = read(fp, data, toread * scan_size);
 651                 if (read_size < 0) {
 652                         if (errno == EAGAIN) {
 653                                 fprintf(stderr, "nothing available\n");
 654                                 continue;
 655                         } else {
 656                                 break;
 657                         }
 658                 }
 659                 for (i = 0; i < read_size / scan_size; i++)
 660                         process_scan(data + scan_size * i, channels,
 661                                      num_channels);
 662         }
 663
 664 error:
 665         cleanup();
 666
 667         if (fp >= 0 && close(fp) == -1)
 668                 perror("Failed to close buffer");
 669         free(buffer_access);
 670         free(data);
 671         free(buf_dir_name);
 672         for (i = num_channels - 1; i >= 0; i--) {
 673                 free(channels[i].name);
 674                 free(channels[i].generic_name);
 675         }
 676         free(channels);
 677         free(trigger_name);
 678         free(device_name);
 679         free(dev_dir_name);
 680
 681         return ret;
 682 }