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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 */
42enum 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 **/
56int 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
75void 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
92void 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
115void 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
138void 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 **/
174void 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
205static 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
245void 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
264enum autochan autochannels = AUTOCHANNELS_DISABLED;
265char *dev_dir_name = NULL;
266char *buf_dir_name = NULL;
267bool current_trigger_set = false;
268
269void 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
301void sig_handler(int signum)
302{
303 fprintf(stderr, "Caught signal %d\n", signum);
304 cleanup();
305 exit(-signum);
306}
307
308void 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
323static 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
331int 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
672error:
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}