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1// SPDX-License-Identifier: GPL-2.0-only
2/* Industrialio buffer test code.
3 *
4 * Copyright (c) 2008 Jonathan Cameron
5 *
6 * This program is primarily intended as an example application.
7 * Reads the current buffer setup from sysfs and starts a short capture
8 * from the specified device, pretty printing the result after appropriate
9 * conversion.
10 *
11 * Command line parameters
12 * generic_buffer -n <device_name> -t <trigger_name>
13 * If trigger name is not specified the program assumes you want a dataready
14 * 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 "iio_utils.h"
34
35/**
36 * enum autochan - state for the automatic channel enabling mechanism
37 */
38enum autochan {
39 AUTOCHANNELS_DISABLED,
40 AUTOCHANNELS_ENABLED,
41 AUTOCHANNELS_ACTIVE,
42};
43
44/**
45 * size_from_channelarray() - calculate the storage size of a scan
46 * @channels: the channel info array
47 * @num_channels: number of channels
48 *
49 * Has the side effect of filling the channels[i].location values used
50 * in processing the buffer output.
51 **/
52int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
53{
54 int bytes = 0;
55 int i = 0;
56
57 while (i < num_channels) {
58 if (bytes % channels[i].bytes == 0)
59 channels[i].location = bytes;
60 else
61 channels[i].location = bytes - bytes % channels[i].bytes
62 + channels[i].bytes;
63
64 bytes = channels[i].location + channels[i].bytes;
65 i++;
66 }
67
68 return bytes;
69}
70
71void print1byte(uint8_t input, struct iio_channel_info *info)
72{
73 /*
74 * Shift before conversion to avoid sign extension
75 * of left aligned data
76 */
77 input >>= info->shift;
78 input &= info->mask;
79 if (info->is_signed) {
80 int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
81 (8 - info->bits_used);
82 printf("%05f ", ((float)val + info->offset) * info->scale);
83 } else {
84 printf("%05f ", ((float)input + info->offset) * info->scale);
85 }
86}
87
88void print2byte(uint16_t input, struct iio_channel_info *info)
89{
90 /* First swap if incorrect endian */
91 if (info->be)
92 input = be16toh(input);
93 else
94 input = le16toh(input);
95
96 /*
97 * Shift before conversion to avoid sign extension
98 * of left aligned data
99 */
100 input >>= info->shift;
101 input &= info->mask;
102 if (info->is_signed) {
103 int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
104 (16 - info->bits_used);
105 printf("%05f ", ((float)val + info->offset) * info->scale);
106 } else {
107 printf("%05f ", ((float)input + info->offset) * info->scale);
108 }
109}
110
111void print4byte(uint32_t input, struct iio_channel_info *info)
112{
113 /* First swap if incorrect endian */
114 if (info->be)
115 input = be32toh(input);
116 else
117 input = le32toh(input);
118
119 /*
120 * Shift before conversion to avoid sign extension
121 * of left aligned data
122 */
123 input >>= info->shift;
124 input &= info->mask;
125 if (info->is_signed) {
126 int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
127 (32 - info->bits_used);
128 printf("%05f ", ((float)val + info->offset) * info->scale);
129 } else {
130 printf("%05f ", ((float)input + info->offset) * info->scale);
131 }
132}
133
134void print8byte(uint64_t input, struct iio_channel_info *info)
135{
136 /* First swap if incorrect endian */
137 if (info->be)
138 input = be64toh(input);
139 else
140 input = le64toh(input);
141
142 /*
143 * Shift before conversion to avoid sign extension
144 * of left aligned data
145 */
146 input >>= info->shift;
147 input &= info->mask;
148 if (info->is_signed) {
149 int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
150 (64 - info->bits_used);
151 /* special case for timestamp */
152 if (info->scale == 1.0f && info->offset == 0.0f)
153 printf("%" PRId64 " ", val);
154 else
155 printf("%05f ",
156 ((float)val + info->offset) * info->scale);
157 } else {
158 printf("%05f ", ((float)input + info->offset) * info->scale);
159 }
160}
161
162/**
163 * process_scan() - print out the values in SI units
164 * @data: pointer to the start of the scan
165 * @channels: information about the channels.
166 * Note: size_from_channelarray must have been called first
167 * to fill the location offsets.
168 * @num_channels: number of channels
169 **/
170void process_scan(char *data,
171 struct iio_channel_info *channels,
172 int num_channels)
173{
174 int k;
175
176 for (k = 0; k < num_channels; k++)
177 switch (channels[k].bytes) {
178 /* only a few cases implemented so far */
179 case 1:
180 print1byte(*(uint8_t *)(data + channels[k].location),
181 &channels[k]);
182 break;
183 case 2:
184 print2byte(*(uint16_t *)(data + channels[k].location),
185 &channels[k]);
186 break;
187 case 4:
188 print4byte(*(uint32_t *)(data + channels[k].location),
189 &channels[k]);
190 break;
191 case 8:
192 print8byte(*(uint64_t *)(data + channels[k].location),
193 &channels[k]);
194 break;
195 default:
196 break;
197 }
198 printf("\n");
199}
200
201static int enable_disable_all_channels(char *dev_dir_name, int enable)
202{
203 const struct dirent *ent;
204 char scanelemdir[256];
205 DIR *dp;
206 int ret;
207
208 snprintf(scanelemdir, sizeof(scanelemdir),
209 FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name);
210 scanelemdir[sizeof(scanelemdir)-1] = '\0';
211
212 dp = opendir(scanelemdir);
213 if (!dp) {
214 fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
215 scanelemdir);
216 return -EIO;
217 }
218
219 ret = -ENOENT;
220 while (ent = readdir(dp), ent) {
221 if (iioutils_check_suffix(ent->d_name, "_en")) {
222 printf("%sabling: %s\n",
223 enable ? "En" : "Dis",
224 ent->d_name);
225 ret = write_sysfs_int(ent->d_name, scanelemdir,
226 enable);
227 if (ret < 0)
228 fprintf(stderr, "Failed to enable/disable %s\n",
229 ent->d_name);
230 }
231 }
232
233 if (closedir(dp) == -1) {
234 perror("Enabling/disabling channels: "
235 "Failed to close directory");
236 return -errno;
237 }
238 return 0;
239}
240
241void print_usage(void)
242{
243 fprintf(stderr, "Usage: generic_buffer [options]...\n"
244 "Capture, convert and output data from IIO device buffer\n"
245 " -a Auto-activate all available channels\n"
246 " -A Force-activate ALL channels\n"
247 " -c <n> Do n conversions, or loop forever if n < 0\n"
248 " -e Disable wait for event (new data)\n"
249 " -g Use trigger-less mode\n"
250 " -l <n> Set buffer length to n samples\n"
251 " --device-name -n <name>\n"
252 " --device-num -N <num>\n"
253 " Set device by name or number (mandatory)\n"
254 " --trigger-name -t <name>\n"
255 " --trigger-num -T <num>\n"
256 " Set trigger by name or number\n"
257 " -w <n> Set delay between reads in us (event-less mode)\n");
258}
259
260enum autochan autochannels = AUTOCHANNELS_DISABLED;
261char *dev_dir_name = NULL;
262char *buf_dir_name = NULL;
263bool current_trigger_set = false;
264
265void cleanup(void)
266{
267 int ret;
268
269 /* Disable trigger */
270 if (dev_dir_name && current_trigger_set) {
271 /* Disconnect the trigger - just write a dummy name. */
272 ret = write_sysfs_string("trigger/current_trigger",
273 dev_dir_name, "NULL");
274 if (ret < 0)
275 fprintf(stderr, "Failed to disable trigger: %s\n",
276 strerror(-ret));
277 current_trigger_set = false;
278 }
279
280 /* Disable buffer */
281 if (buf_dir_name) {
282 ret = write_sysfs_int("enable", buf_dir_name, 0);
283 if (ret < 0)
284 fprintf(stderr, "Failed to disable buffer: %s\n",
285 strerror(-ret));
286 }
287
288 /* Disable channels if auto-enabled */
289 if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
290 ret = enable_disable_all_channels(dev_dir_name, 0);
291 if (ret)
292 fprintf(stderr, "Failed to disable all channels\n");
293 autochannels = AUTOCHANNELS_DISABLED;
294 }
295}
296
297void sig_handler(int signum)
298{
299 fprintf(stderr, "Caught signal %d\n", signum);
300 cleanup();
301 exit(-signum);
302}
303
304void register_cleanup(void)
305{
306 struct sigaction sa = { .sa_handler = sig_handler };
307 const int signums[] = { SIGINT, SIGTERM, SIGABRT };
308 int ret, i;
309
310 for (i = 0; i < ARRAY_SIZE(signums); ++i) {
311 ret = sigaction(signums[i], &sa, NULL);
312 if (ret) {
313 perror("Failed to register signal handler");
314 exit(-1);
315 }
316 }
317}
318
319static const struct option longopts[] = {
320 { "device-name", 1, 0, 'n' },
321 { "device-num", 1, 0, 'N' },
322 { "trigger-name", 1, 0, 't' },
323 { "trigger-num", 1, 0, 'T' },
324 { },
325};
326
327int main(int argc, char **argv)
328{
329 long long num_loops = 2;
330 unsigned long timedelay = 1000000;
331 unsigned long buf_len = 128;
332
333 ssize_t i;
334 unsigned long long j;
335 unsigned long toread;
336 int ret, c;
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 bool force_autochannels = false;
351
352 struct iio_channel_info *channels = NULL;
353
354 register_cleanup();
355
356 while ((c = getopt_long(argc, argv, "aAc:egl:n:N:t:T:w:?", longopts,
357 NULL)) != -1) {
358 switch (c) {
359 case 'a':
360 autochannels = AUTOCHANNELS_ENABLED;
361 break;
362 case 'A':
363 autochannels = AUTOCHANNELS_ENABLED;
364 force_autochannels = true;
365 break;
366 case 'c':
367 errno = 0;
368 num_loops = strtoll(optarg, &dummy, 10);
369 if (errno) {
370 ret = -errno;
371 goto error;
372 }
373
374 break;
375 case 'e':
376 noevents = 1;
377 break;
378 case 'g':
379 notrigger = 1;
380 break;
381 case 'l':
382 errno = 0;
383 buf_len = strtoul(optarg, &dummy, 10);
384 if (errno) {
385 ret = -errno;
386 goto error;
387 }
388
389 break;
390 case 'n':
391 device_name = strdup(optarg);
392 break;
393 case 'N':
394 errno = 0;
395 dev_num = strtoul(optarg, &dummy, 10);
396 if (errno) {
397 ret = -errno;
398 goto error;
399 }
400 break;
401 case 't':
402 trigger_name = strdup(optarg);
403 break;
404 case 'T':
405 errno = 0;
406 trig_num = strtoul(optarg, &dummy, 10);
407 if (errno)
408 return -errno;
409 break;
410 case 'w':
411 errno = 0;
412 timedelay = strtoul(optarg, &dummy, 10);
413 if (errno) {
414 ret = -errno;
415 goto error;
416 }
417 break;
418 case '?':
419 print_usage();
420 ret = -1;
421 goto error;
422 }
423 }
424
425 /* Find the device requested */
426 if (dev_num < 0 && !device_name) {
427 fprintf(stderr, "Device not set\n");
428 print_usage();
429 ret = -1;
430 goto error;
431 } else if (dev_num >= 0 && device_name) {
432 fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
433 print_usage();
434 ret = -1;
435 goto error;
436 } else if (dev_num < 0) {
437 dev_num = find_type_by_name(device_name, "iio:device");
438 if (dev_num < 0) {
439 fprintf(stderr, "Failed to find the %s\n", device_name);
440 ret = dev_num;
441 goto error;
442 }
443 }
444 printf("iio device number being used is %d\n", dev_num);
445
446 ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
447 if (ret < 0)
448 return -ENOMEM;
449 /* Fetch device_name if specified by number */
450 if (!device_name) {
451 device_name = malloc(IIO_MAX_NAME_LENGTH);
452 if (!device_name) {
453 ret = -ENOMEM;
454 goto error;
455 }
456 ret = read_sysfs_string("name", dev_dir_name, device_name);
457 if (ret < 0) {
458 fprintf(stderr, "Failed to read name of device %d\n", dev_num);
459 goto error;
460 }
461 }
462
463 if (notrigger) {
464 printf("trigger-less mode selected\n");
465 } else if (trig_num >= 0) {
466 char *trig_dev_name;
467 ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
468 if (ret < 0) {
469 return -ENOMEM;
470 }
471 trigger_name = malloc(IIO_MAX_NAME_LENGTH);
472 ret = read_sysfs_string("name", trig_dev_name, trigger_name);
473 free(trig_dev_name);
474 if (ret < 0) {
475 fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
476 return ret;
477 }
478 printf("iio trigger number being used is %d\n", trig_num);
479 } else {
480 if (!trigger_name) {
481 /*
482 * Build the trigger name. If it is device associated
483 * its name is <device_name>_dev[n] where n matches
484 * the device number found above.
485 */
486 ret = asprintf(&trigger_name,
487 "%s-dev%d", device_name, dev_num);
488 if (ret < 0) {
489 ret = -ENOMEM;
490 goto error;
491 }
492 }
493
494 /* Look for this "-devN" trigger */
495 trig_num = find_type_by_name(trigger_name, "trigger");
496 if (trig_num < 0) {
497 /* OK try the simpler "-trigger" suffix instead */
498 free(trigger_name);
499 ret = asprintf(&trigger_name,
500 "%s-trigger", device_name);
501 if (ret < 0) {
502 ret = -ENOMEM;
503 goto error;
504 }
505 }
506
507 trig_num = find_type_by_name(trigger_name, "trigger");
508 if (trig_num < 0) {
509 fprintf(stderr, "Failed to find the trigger %s\n",
510 trigger_name);
511 ret = trig_num;
512 goto error;
513 }
514
515 printf("iio trigger number being used is %d\n", trig_num);
516 }
517
518 /*
519 * Parse the files in scan_elements to identify what channels are
520 * present
521 */
522 ret = build_channel_array(dev_dir_name, &channels, &num_channels);
523 if (ret) {
524 fprintf(stderr, "Problem reading scan element information\n"
525 "diag %s\n", dev_dir_name);
526 goto error;
527 }
528 if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&
529 !force_autochannels) {
530 fprintf(stderr, "Auto-channels selected but some channels "
531 "are already activated in sysfs\n");
532 fprintf(stderr, "Proceeding without activating any channels\n");
533 }
534
535 if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||
536 (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {
537 fprintf(stderr, "Enabling all channels\n");
538
539 ret = enable_disable_all_channels(dev_dir_name, 1);
540 if (ret) {
541 fprintf(stderr, "Failed to enable all channels\n");
542 goto error;
543 }
544
545 /* This flags that we need to disable the channels again */
546 autochannels = AUTOCHANNELS_ACTIVE;
547
548 ret = build_channel_array(dev_dir_name, &channels,
549 &num_channels);
550 if (ret) {
551 fprintf(stderr, "Problem reading scan element "
552 "information\n"
553 "diag %s\n", dev_dir_name);
554 goto error;
555 }
556 if (!num_channels) {
557 fprintf(stderr, "Still no channels after "
558 "auto-enabling, giving up\n");
559 goto error;
560 }
561 }
562
563 if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
564 fprintf(stderr,
565 "No channels are enabled, we have nothing to scan.\n");
566 fprintf(stderr, "Enable channels manually in "
567 FORMAT_SCAN_ELEMENTS_DIR
568 "/*_en or pass -a to autoenable channels and "
569 "try again.\n", dev_dir_name);
570 ret = -ENOENT;
571 goto error;
572 }
573
574 /*
575 * Construct the directory name for the associated buffer.
576 * As we know that the lis3l02dq has only one buffer this may
577 * be built rather than found.
578 */
579 ret = asprintf(&buf_dir_name,
580 "%siio:device%d/buffer", iio_dir, dev_num);
581 if (ret < 0) {
582 ret = -ENOMEM;
583 goto error;
584 }
585
586 if (!notrigger) {
587 printf("%s %s\n", dev_dir_name, trigger_name);
588 /*
589 * Set the device trigger to be the data ready trigger found
590 * above
591 */
592 ret = write_sysfs_string_and_verify("trigger/current_trigger",
593 dev_dir_name,
594 trigger_name);
595 if (ret < 0) {
596 fprintf(stderr,
597 "Failed to write current_trigger file\n");
598 goto error;
599 }
600 }
601
602 /* Setup ring buffer parameters */
603 ret = write_sysfs_int("length", buf_dir_name, buf_len);
604 if (ret < 0)
605 goto error;
606
607 /* Enable the buffer */
608 ret = write_sysfs_int("enable", buf_dir_name, 1);
609 if (ret < 0) {
610 fprintf(stderr,
611 "Failed to enable buffer: %s\n", strerror(-ret));
612 goto error;
613 }
614
615 scan_size = size_from_channelarray(channels, num_channels);
616 data = malloc(scan_size * buf_len);
617 if (!data) {
618 ret = -ENOMEM;
619 goto error;
620 }
621
622 ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
623 if (ret < 0) {
624 ret = -ENOMEM;
625 goto error;
626 }
627
628 /* Attempt to open non blocking the access dev */
629 fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
630 if (fp == -1) { /* TODO: If it isn't there make the node */
631 ret = -errno;
632 fprintf(stderr, "Failed to open %s\n", buffer_access);
633 goto error;
634 }
635
636 for (j = 0; j < num_loops || num_loops < 0; j++) {
637 if (!noevents) {
638 struct pollfd pfd = {
639 .fd = fp,
640 .events = POLLIN,
641 };
642
643 ret = poll(&pfd, 1, -1);
644 if (ret < 0) {
645 ret = -errno;
646 goto error;
647 } else if (ret == 0) {
648 continue;
649 }
650
651 toread = buf_len;
652 } else {
653 usleep(timedelay);
654 toread = 64;
655 }
656
657 read_size = read(fp, data, toread * scan_size);
658 if (read_size < 0) {
659 if (errno == EAGAIN) {
660 fprintf(stderr, "nothing available\n");
661 continue;
662 } else {
663 break;
664 }
665 }
666 for (i = 0; i < read_size / scan_size; i++)
667 process_scan(data + scan_size * i, channels,
668 num_channels);
669 }
670
671error:
672 cleanup();
673
674 if (fp >= 0 && close(fp) == -1)
675 perror("Failed to close buffer");
676 free(buffer_access);
677 free(data);
678 free(buf_dir_name);
679 for (i = num_channels - 1; i >= 0; i--) {
680 free(channels[i].name);
681 free(channels[i].generic_name);
682 }
683 free(channels);
684 free(trigger_name);
685 free(device_name);
686 free(dev_dir_name);
687
688 return ret;
689}