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1// SPDX-License-Identifier: GPL-2.0-only2/* Industrialio buffer test code.3 *4 * Copyright (c) 2008 Jonathan Cameron5 *6 * This program is primarily intended as an example application.7 * Reads the current buffer setup from sysfs and starts a short capture8 * from the specified device, pretty printing the result after appropriate9 * conversion.10 *11 * Command line parameters12 * generic_buffer -n <device_name> -t <trigger_name>13 * If trigger name is not specified the program assumes you want a dataready14 * 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 <sys/ioctl.h>34#include <linux/iio/buffer.h>35#include "iio_utils.h"36 37/**38 * enum autochan - state for the automatic channel enabling mechanism39 */40enum autochan {41 AUTOCHANNELS_DISABLED,42 AUTOCHANNELS_ENABLED,43 AUTOCHANNELS_ACTIVE,44};45 46/**47 * size_from_channelarray() - calculate the storage size of a scan48 * @channels: the channel info array49 * @num_channels: number of channels50 *51 * Has the side effect of filling the channels[i].location values used52 * in processing the buffer output.53 **/54static unsigned int size_from_channelarray(struct iio_channel_info *channels, int num_channels)55{56 unsigned int bytes = 0;57 int i = 0, max = 0;58 unsigned int misalignment;59 60 while (i < num_channels) {61 if (channels[i].bytes > max)62 max = channels[i].bytes;63 if (bytes % channels[i].bytes == 0)64 channels[i].location = bytes;65 else66 channels[i].location = bytes - bytes % channels[i].bytes67 + channels[i].bytes;68 69 bytes = channels[i].location + channels[i].bytes;70 i++;71 }72 /*73 * We want the data in next sample to also be properly aligned so74 * we'll add padding at the end if needed. Adding padding only75 * works for channel data which size is 2^n bytes.76 */77 misalignment = bytes % max;78 if (misalignment)79 bytes += max - misalignment;80 81 return bytes;82}83 84static void print1byte(uint8_t input, struct iio_channel_info *info)85{86 /*87 * Shift before conversion to avoid sign extension88 * of left aligned data89 */90 input >>= info->shift;91 input &= info->mask;92 if (info->is_signed) {93 int8_t val = (int8_t)(input << (8 - info->bits_used)) >>94 (8 - info->bits_used);95 printf("%05f ", ((float)val + info->offset) * info->scale);96 } else {97 printf("%05f ", ((float)input + info->offset) * info->scale);98 }99}100 101static void print2byte(uint16_t input, struct iio_channel_info *info)102{103 /* First swap if incorrect endian */104 if (info->be)105 input = be16toh(input);106 else107 input = le16toh(input);108 109 /*110 * Shift before conversion to avoid sign extension111 * of left aligned data112 */113 input >>= info->shift;114 input &= info->mask;115 if (info->is_signed) {116 int16_t val = (int16_t)(input << (16 - info->bits_used)) >>117 (16 - info->bits_used);118 printf("%05f ", ((float)val + info->offset) * info->scale);119 } else {120 printf("%05f ", ((float)input + info->offset) * info->scale);121 }122}123 124static void print4byte(uint32_t input, struct iio_channel_info *info)125{126 /* First swap if incorrect endian */127 if (info->be)128 input = be32toh(input);129 else130 input = le32toh(input);131 132 /*133 * Shift before conversion to avoid sign extension134 * of left aligned data135 */136 input >>= info->shift;137 input &= info->mask;138 if (info->is_signed) {139 int32_t val = (int32_t)(input << (32 - info->bits_used)) >>140 (32 - info->bits_used);141 printf("%05f ", ((float)val + info->offset) * info->scale);142 } else {143 printf("%05f ", ((float)input + info->offset) * info->scale);144 }145}146 147static void print8byte(uint64_t input, struct iio_channel_info *info)148{149 /* First swap if incorrect endian */150 if (info->be)151 input = be64toh(input);152 else153 input = le64toh(input);154 155 /*156 * Shift before conversion to avoid sign extension157 * of left aligned data158 */159 input >>= info->shift;160 input &= info->mask;161 if (info->is_signed) {162 int64_t val = (int64_t)(input << (64 - info->bits_used)) >>163 (64 - info->bits_used);164 /* special case for timestamp */165 if (info->scale == 1.0f && info->offset == 0.0f)166 printf("%" PRId64 " ", val);167 else168 printf("%05f ",169 ((float)val + info->offset) * info->scale);170 } else {171 printf("%05f ", ((float)input + info->offset) * info->scale);172 }173}174 175/**176 * process_scan() - print out the values in SI units177 * @data: pointer to the start of the scan178 * @channels: information about the channels.179 * Note: size_from_channelarray must have been called first180 * to fill the location offsets.181 * @num_channels: number of channels182 **/183static void process_scan(char *data, struct iio_channel_info *channels,184 int num_channels)185{186 int k;187 188 for (k = 0; k < num_channels; k++)189 switch (channels[k].bytes) {190 /* only a few cases implemented so far */191 case 1:192 print1byte(*(uint8_t *)(data + channels[k].location),193 &channels[k]);194 break;195 case 2:196 print2byte(*(uint16_t *)(data + channels[k].location),197 &channels[k]);198 break;199 case 4:200 print4byte(*(uint32_t *)(data + channels[k].location),201 &channels[k]);202 break;203 case 8:204 print8byte(*(uint64_t *)(data + channels[k].location),205 &channels[k]);206 break;207 default:208 break;209 }210 printf("\n");211}212 213static int enable_disable_all_channels(char *dev_dir_name, int buffer_idx, int enable)214{215 const struct dirent *ent;216 char scanelemdir[256];217 DIR *dp;218 int ret;219 220 snprintf(scanelemdir, sizeof(scanelemdir),221 FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name, buffer_idx);222 scanelemdir[sizeof(scanelemdir)-1] = '\0';223 224 dp = opendir(scanelemdir);225 if (!dp) {226 fprintf(stderr, "Enabling/disabling channels: can't open %s\n",227 scanelemdir);228 return -EIO;229 }230 231 ret = -ENOENT;232 while (ent = readdir(dp), ent) {233 if (iioutils_check_suffix(ent->d_name, "_en")) {234 printf("%sabling: %s\n",235 enable ? "En" : "Dis",236 ent->d_name);237 ret = write_sysfs_int(ent->d_name, scanelemdir,238 enable);239 if (ret < 0)240 fprintf(stderr, "Failed to enable/disable %s\n",241 ent->d_name);242 }243 }244 245 if (closedir(dp) == -1) {246 perror("Enabling/disabling channels: "247 "Failed to close directory");248 return -errno;249 }250 return 0;251}252 253static void print_usage(void)254{255 fprintf(stderr, "Usage: generic_buffer [options]...\n"256 "Capture, convert and output data from IIO device buffer\n"257 " -a Auto-activate all available channels\n"258 " -A Force-activate ALL channels\n"259 " -b <n> The buffer which to open (by index), default 0\n"260 " -c <n> Do n conversions, or loop forever if n < 0\n"261 " -e Disable wait for event (new data)\n"262 " -g Use trigger-less mode\n"263 " -l <n> Set buffer length to n samples\n"264 " --device-name -n <name>\n"265 " --device-num -N <num>\n"266 " Set device by name or number (mandatory)\n"267 " --trigger-name -t <name>\n"268 " --trigger-num -T <num>\n"269 " Set trigger by name or number\n"270 " -w <n> Set delay between reads in us (event-less mode)\n");271}272 273static enum autochan autochannels = AUTOCHANNELS_DISABLED;274static char *dev_dir_name = NULL;275static char *buf_dir_name = NULL;276static int buffer_idx = 0;277static bool current_trigger_set = false;278 279static void cleanup(void)280{281 int ret;282 283 /* Disable trigger */284 if (dev_dir_name && current_trigger_set) {285 /* Disconnect the trigger - just write a dummy name. */286 ret = write_sysfs_string("trigger/current_trigger",287 dev_dir_name, "NULL");288 if (ret < 0)289 fprintf(stderr, "Failed to disable trigger: %s\n",290 strerror(-ret));291 current_trigger_set = false;292 }293 294 /* Disable buffer */295 if (buf_dir_name) {296 ret = write_sysfs_int("enable", buf_dir_name, 0);297 if (ret < 0)298 fprintf(stderr, "Failed to disable buffer: %s\n",299 strerror(-ret));300 }301 302 /* Disable channels if auto-enabled */303 if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {304 ret = enable_disable_all_channels(dev_dir_name, buffer_idx, 0);305 if (ret)306 fprintf(stderr, "Failed to disable all channels\n");307 autochannels = AUTOCHANNELS_DISABLED;308 }309}310 311static void sig_handler(int signum)312{313 fprintf(stderr, "Caught signal %d\n", signum);314 cleanup();315 exit(-signum);316}317 318static void register_cleanup(void)319{320 struct sigaction sa = { .sa_handler = sig_handler };321 const int signums[] = { SIGINT, SIGTERM, SIGABRT };322 int ret, i;323 324 for (i = 0; i < ARRAY_SIZE(signums); ++i) {325 ret = sigaction(signums[i], &sa, NULL);326 if (ret) {327 perror("Failed to register signal handler");328 exit(-1);329 }330 }331}332 333static const struct option longopts[] = {334 { "device-name", 1, 0, 'n' },335 { "device-num", 1, 0, 'N' },336 { "trigger-name", 1, 0, 't' },337 { "trigger-num", 1, 0, 'T' },338 { },339};340 341int main(int argc, char **argv)342{343 long long num_loops = 2;344 unsigned long timedelay = 1000000;345 unsigned long buf_len = 128;346 347 ssize_t i;348 unsigned long long j;349 unsigned long toread;350 int ret, c;351 struct stat st;352 int fd = -1;353 int buf_fd = -1;354 355 int num_channels = 0;356 char *trigger_name = NULL, *device_name = NULL;357 358 char *data = NULL;359 ssize_t read_size;360 int dev_num = -1, trig_num = -1;361 char *buffer_access = NULL;362 unsigned int scan_size;363 int noevents = 0;364 int notrigger = 0;365 char *dummy;366 bool force_autochannels = false;367 368 struct iio_channel_info *channels = NULL;369 370 register_cleanup();371 372 while ((c = getopt_long(argc, argv, "aAb:c:egl:n:N:t:T:w:?", longopts,373 NULL)) != -1) {374 switch (c) {375 case 'a':376 autochannels = AUTOCHANNELS_ENABLED;377 break;378 case 'A':379 autochannels = AUTOCHANNELS_ENABLED;380 force_autochannels = true;381 break;382 case 'b':383 errno = 0;384 buffer_idx = strtoll(optarg, &dummy, 10);385 if (errno) {386 ret = -errno;387 goto error;388 }389 if (buffer_idx < 0) {390 ret = -ERANGE;391 goto error;392 }393 394 break;395 case 'c':396 errno = 0;397 num_loops = strtoll(optarg, &dummy, 10);398 if (errno) {399 ret = -errno;400 goto error;401 }402 403 break;404 case 'e':405 noevents = 1;406 break;407 case 'g':408 notrigger = 1;409 break;410 case 'l':411 errno = 0;412 buf_len = strtoul(optarg, &dummy, 10);413 if (errno) {414 ret = -errno;415 goto error;416 }417 418 break;419 case 'n':420 device_name = strdup(optarg);421 break;422 case 'N':423 errno = 0;424 dev_num = strtoul(optarg, &dummy, 10);425 if (errno) {426 ret = -errno;427 goto error;428 }429 break;430 case 't':431 trigger_name = strdup(optarg);432 break;433 case 'T':434 errno = 0;435 trig_num = strtoul(optarg, &dummy, 10);436 if (errno)437 return -errno;438 break;439 case 'w':440 errno = 0;441 timedelay = strtoul(optarg, &dummy, 10);442 if (errno) {443 ret = -errno;444 goto error;445 }446 break;447 case '?':448 print_usage();449 ret = -1;450 goto error;451 }452 }453 454 /* Find the device requested */455 if (dev_num < 0 && !device_name) {456 fprintf(stderr, "Device not set\n");457 print_usage();458 ret = -1;459 goto error;460 } else if (dev_num >= 0 && device_name) {461 fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");462 print_usage();463 ret = -1;464 goto error;465 } else if (dev_num < 0) {466 dev_num = find_type_by_name(device_name, "iio:device");467 if (dev_num < 0) {468 fprintf(stderr, "Failed to find the %s\n", device_name);469 ret = dev_num;470 goto error;471 }472 }473 printf("iio device number being used is %d\n", dev_num);474 475 ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);476 if (ret < 0)477 return -ENOMEM;478 /* Fetch device_name if specified by number */479 if (!device_name) {480 device_name = malloc(IIO_MAX_NAME_LENGTH);481 if (!device_name) {482 ret = -ENOMEM;483 goto error;484 }485 ret = read_sysfs_string("name", dev_dir_name, device_name);486 if (ret < 0) {487 fprintf(stderr, "Failed to read name of device %d\n", dev_num);488 goto error;489 }490 }491 492 if (notrigger) {493 printf("trigger-less mode selected\n");494 } else if (trig_num >= 0) {495 char *trig_dev_name;496 ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);497 if (ret < 0) {498 return -ENOMEM;499 }500 trigger_name = malloc(IIO_MAX_NAME_LENGTH);501 if (!trigger_name) {502 ret = -ENOMEM;503 goto error;504 }505 ret = read_sysfs_string("name", trig_dev_name, trigger_name);506 free(trig_dev_name);507 if (ret < 0) {508 fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);509 return ret;510 }511 printf("iio trigger number being used is %d\n", trig_num);512 } else {513 if (!trigger_name) {514 /*515 * Build the trigger name. If it is device associated516 * its name is <device_name>_dev[n] where n matches517 * the device number found above.518 */519 ret = asprintf(&trigger_name,520 "%s-dev%d", device_name, dev_num);521 if (ret < 0) {522 ret = -ENOMEM;523 goto error;524 }525 }526 527 /* Look for this "-devN" trigger */528 trig_num = find_type_by_name(trigger_name, "trigger");529 if (trig_num < 0) {530 /* OK try the simpler "-trigger" suffix instead */531 free(trigger_name);532 ret = asprintf(&trigger_name,533 "%s-trigger", device_name);534 if (ret < 0) {535 ret = -ENOMEM;536 goto error;537 }538 }539 540 trig_num = find_type_by_name(trigger_name, "trigger");541 if (trig_num < 0) {542 fprintf(stderr, "Failed to find the trigger %s\n",543 trigger_name);544 ret = trig_num;545 goto error;546 }547 548 printf("iio trigger number being used is %d\n", trig_num);549 }550 551 /*552 * Parse the files in scan_elements to identify what channels are553 * present554 */555 ret = build_channel_array(dev_dir_name, buffer_idx, &channels, &num_channels);556 if (ret) {557 fprintf(stderr, "Problem reading scan element information\n"558 "diag %s\n", dev_dir_name);559 goto error;560 }561 if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&562 !force_autochannels) {563 fprintf(stderr, "Auto-channels selected but some channels "564 "are already activated in sysfs\n");565 fprintf(stderr, "Proceeding without activating any channels\n");566 }567 568 if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||569 (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {570 fprintf(stderr, "Enabling all channels\n");571 572 ret = enable_disable_all_channels(dev_dir_name, buffer_idx, 1);573 if (ret) {574 fprintf(stderr, "Failed to enable all channels\n");575 goto error;576 }577 578 /* This flags that we need to disable the channels again */579 autochannels = AUTOCHANNELS_ACTIVE;580 581 ret = build_channel_array(dev_dir_name, buffer_idx, &channels,582 &num_channels);583 if (ret) {584 fprintf(stderr, "Problem reading scan element "585 "information\n"586 "diag %s\n", dev_dir_name);587 goto error;588 }589 if (!num_channels) {590 fprintf(stderr, "Still no channels after "591 "auto-enabling, giving up\n");592 goto error;593 }594 }595 596 if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {597 fprintf(stderr,598 "No channels are enabled, we have nothing to scan.\n");599 fprintf(stderr, "Enable channels manually in "600 FORMAT_SCAN_ELEMENTS_DIR601 "/*_en or pass -a to autoenable channels and "602 "try again.\n", dev_dir_name, buffer_idx);603 ret = -ENOENT;604 goto error;605 }606 607 /*608 * Construct the directory name for the associated buffer.609 * As we know that the lis3l02dq has only one buffer this may610 * be built rather than found.611 */612 ret = asprintf(&buf_dir_name,613 "%siio:device%d/buffer%d", iio_dir, dev_num, buffer_idx);614 if (ret < 0) {615 ret = -ENOMEM;616 goto error;617 }618 619 if (stat(buf_dir_name, &st)) {620 fprintf(stderr, "Could not stat() '%s', got error %d: %s\n",621 buf_dir_name, errno, strerror(errno));622 ret = -errno;623 goto error;624 }625 626 if (!S_ISDIR(st.st_mode)) {627 fprintf(stderr, "File '%s' is not a directory\n", buf_dir_name);628 ret = -EFAULT;629 goto error;630 }631 632 if (!notrigger) {633 printf("%s %s\n", dev_dir_name, trigger_name);634 /*635 * Set the device trigger to be the data ready trigger found636 * above637 */638 ret = write_sysfs_string_and_verify("trigger/current_trigger",639 dev_dir_name,640 trigger_name);641 if (ret < 0) {642 fprintf(stderr,643 "Failed to write current_trigger file\n");644 goto error;645 }646 }647 648 ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);649 if (ret < 0) {650 ret = -ENOMEM;651 goto error;652 }653 654 /* Attempt to open non blocking the access dev */655 fd = open(buffer_access, O_RDONLY | O_NONBLOCK);656 if (fd == -1) { /* TODO: If it isn't there make the node */657 ret = -errno;658 fprintf(stderr, "Failed to open %s\n", buffer_access);659 goto error;660 }661 662 /* specify for which buffer index we want an FD */663 buf_fd = buffer_idx;664 665 ret = ioctl(fd, IIO_BUFFER_GET_FD_IOCTL, &buf_fd);666 if (ret == -1 || buf_fd == -1) {667 ret = -errno;668 if (ret == -ENODEV || ret == -EINVAL)669 fprintf(stderr,670 "Device does not have this many buffers\n");671 else672 fprintf(stderr, "Failed to retrieve buffer fd\n");673 674 goto error;675 }676 677 /* Setup ring buffer parameters */678 ret = write_sysfs_int("length", buf_dir_name, buf_len);679 if (ret < 0)680 goto error;681 682 /* Enable the buffer */683 ret = write_sysfs_int("enable", buf_dir_name, 1);684 if (ret < 0) {685 fprintf(stderr,686 "Failed to enable buffer '%s': %s\n",687 buf_dir_name, strerror(-ret));688 goto error;689 }690 691 scan_size = size_from_channelarray(channels, num_channels);692 693 size_t total_buf_len = scan_size * buf_len;694 695 if (scan_size > 0 && total_buf_len / scan_size != buf_len) {696 ret = -EFAULT;697 perror("Integer overflow happened when calculate scan_size * buf_len");698 goto error;699 }700 701 data = malloc(total_buf_len);702 if (!data) {703 ret = -ENOMEM;704 goto error;705 }706 707 /**708 * This check is being done here for sanity reasons, however it709 * should be omitted under normal operation.710 * If this is buffer0, we check that we get EBUSY after this point.711 */712 if (buffer_idx == 0) {713 errno = 0;714 read_size = read(fd, data, 1);715 if (read_size > -1 || errno != EBUSY) {716 ret = -EFAULT;717 perror("Reading from '%s' should not be possible after ioctl()");718 goto error;719 }720 }721 722 /* close now the main chardev FD and let the buffer FD work */723 if (close(fd) == -1)724 perror("Failed to close character device file");725 fd = -1;726 727 for (j = 0; j < num_loops || num_loops < 0; j++) {728 if (!noevents) {729 struct pollfd pfd = {730 .fd = buf_fd,731 .events = POLLIN,732 };733 734 ret = poll(&pfd, 1, -1);735 if (ret < 0) {736 ret = -errno;737 goto error;738 } else if (ret == 0) {739 continue;740 }741 742 } else {743 usleep(timedelay);744 }745 746 toread = buf_len;747 748 read_size = read(buf_fd, data, toread * scan_size);749 if (read_size < 0) {750 if (errno == EAGAIN) {751 fprintf(stderr, "nothing available\n");752 continue;753 } else {754 break;755 }756 }757 for (i = 0; i < read_size / scan_size; i++)758 process_scan(data + scan_size * i, channels,759 num_channels);760 }761 762error:763 cleanup();764 765 if (fd >= 0 && close(fd) == -1)766 perror("Failed to close character device");767 if (buf_fd >= 0 && close(buf_fd) == -1)768 perror("Failed to close buffer");769 free(buffer_access);770 free(data);771 free(buf_dir_name);772 for (i = num_channels - 1; i >= 0; i--) {773 free(channels[i].name);774 free(channels[i].generic_name);775 }776 free(channels);777 free(trigger_name);778 free(device_name);779 free(dev_dir_name);780 781 return ret;782}783