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; 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; 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 } 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 } 683