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 */
38 enum 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 **/
size_from_channelarray(struct iio_channel_info * channels,int num_channels)52 static unsigned int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
53 {
54 unsigned int bytes = 0;
55 int i = 0, max = 0;
56 unsigned int misalignment;
57
58 while (i < num_channels) {
59 if (channels[i].bytes > max)
60 max = channels[i].bytes;
61 if (bytes % channels[i].bytes == 0)
62 channels[i].location = bytes;
63 else
64 channels[i].location = bytes - bytes % channels[i].bytes
65 + channels[i].bytes;
66
67 bytes = channels[i].location + channels[i].bytes;
68 i++;
69 }
70 /*
71 * We want the data in next sample to also be properly aligned so
72 * we'll add padding at the end if needed. Adding padding only
73 * works for channel data which size is 2^n bytes.
74 */
75 misalignment = bytes % max;
76 if (misalignment)
77 bytes += max - misalignment;
78
79 return bytes;
80 }
81
print1byte(uint8_t input,struct iio_channel_info * info)82 static void print1byte(uint8_t input, struct iio_channel_info *info)
83 {
84 /*
85 * Shift before conversion to avoid sign extension
86 * of left aligned data
87 */
88 input >>= info->shift;
89 input &= info->mask;
90 if (info->is_signed) {
91 int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
92 (8 - info->bits_used);
93 printf("%05f ", ((float)val + info->offset) * info->scale);
94 } else {
95 printf("%05f ", ((float)input + info->offset) * info->scale);
96 }
97 }
98
print2byte(uint16_t input,struct iio_channel_info * info)99 static void print2byte(uint16_t input, struct iio_channel_info *info)
100 {
101 /* First swap if incorrect endian */
102 if (info->be)
103 input = be16toh(input);
104 else
105 input = le16toh(input);
106
107 /*
108 * Shift before conversion to avoid sign extension
109 * of left aligned data
110 */
111 input >>= info->shift;
112 input &= info->mask;
113 if (info->is_signed) {
114 int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
115 (16 - info->bits_used);
116 printf("%05f ", ((float)val + info->offset) * info->scale);
117 } else {
118 printf("%05f ", ((float)input + info->offset) * info->scale);
119 }
120 }
121
print4byte(uint32_t input,struct iio_channel_info * info)122 static void print4byte(uint32_t input, struct iio_channel_info *info)
123 {
124 /* First swap if incorrect endian */
125 if (info->be)
126 input = be32toh(input);
127 else
128 input = le32toh(input);
129
130 /*
131 * Shift before conversion to avoid sign extension
132 * of left aligned data
133 */
134 input >>= info->shift;
135 input &= info->mask;
136 if (info->is_signed) {
137 int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
138 (32 - info->bits_used);
139 printf("%05f ", ((float)val + info->offset) * info->scale);
140 } else {
141 printf("%05f ", ((float)input + info->offset) * info->scale);
142 }
143 }
144
print8byte(uint64_t input,struct iio_channel_info * info)145 static void print8byte(uint64_t input, struct iio_channel_info *info)
146 {
147 /* First swap if incorrect endian */
148 if (info->be)
149 input = be64toh(input);
150 else
151 input = le64toh(input);
152
153 /*
154 * Shift before conversion to avoid sign extension
155 * of left aligned data
156 */
157 input >>= info->shift;
158 input &= info->mask;
159 if (info->is_signed) {
160 int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
161 (64 - info->bits_used);
162 /* special case for timestamp */
163 if (info->scale == 1.0f && info->offset == 0.0f)
164 printf("%" PRId64 " ", val);
165 else
166 printf("%05f ",
167 ((float)val + info->offset) * info->scale);
168 } else {
169 printf("%05f ", ((float)input + info->offset) * info->scale);
170 }
171 }
172
173 /**
174 * process_scan() - print out the values in SI units
175 * @data: pointer to the start of the scan
176 * @channels: information about the channels.
177 * Note: size_from_channelarray must have been called first
178 * to fill the location offsets.
179 * @num_channels: number of channels
180 **/
process_scan(char * data,struct iio_channel_info * channels,int num_channels)181 static void process_scan(char *data, struct iio_channel_info *channels,
182 int num_channels)
183 {
184 int k;
185
186 for (k = 0; k < num_channels; k++)
187 switch (channels[k].bytes) {
188 /* only a few cases implemented so far */
189 case 1:
190 print1byte(*(uint8_t *)(data + channels[k].location),
191 &channels[k]);
192 break;
193 case 2:
194 print2byte(*(uint16_t *)(data + channels[k].location),
195 &channels[k]);
196 break;
197 case 4:
198 print4byte(*(uint32_t *)(data + channels[k].location),
199 &channels[k]);
200 break;
201 case 8:
202 print8byte(*(uint64_t *)(data + channels[k].location),
203 &channels[k]);
204 break;
205 default:
206 break;
207 }
208 printf("\n");
209 }
210
enable_disable_all_channels(char * dev_dir_name,int enable)211 static int enable_disable_all_channels(char *dev_dir_name, int enable)
212 {
213 const struct dirent *ent;
214 char scanelemdir[256];
215 DIR *dp;
216 int ret;
217
218 snprintf(scanelemdir, sizeof(scanelemdir),
219 FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name);
220 scanelemdir[sizeof(scanelemdir)-1] = '\0';
221
222 dp = opendir(scanelemdir);
223 if (!dp) {
224 fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
225 scanelemdir);
226 return -EIO;
227 }
228
229 ret = -ENOENT;
230 while (ent = readdir(dp), ent) {
231 if (iioutils_check_suffix(ent->d_name, "_en")) {
232 printf("%sabling: %s\n",
233 enable ? "En" : "Dis",
234 ent->d_name);
235 ret = write_sysfs_int(ent->d_name, scanelemdir,
236 enable);
237 if (ret < 0)
238 fprintf(stderr, "Failed to enable/disable %s\n",
239 ent->d_name);
240 }
241 }
242
243 if (closedir(dp) == -1) {
244 perror("Enabling/disabling channels: "
245 "Failed to close directory");
246 return -errno;
247 }
248 return 0;
249 }
250
print_usage(void)251 static void print_usage(void)
252 {
253 fprintf(stderr, "Usage: generic_buffer [options]...\n"
254 "Capture, convert and output data from IIO device buffer\n"
255 " -a Auto-activate all available channels\n"
256 " -A Force-activate ALL channels\n"
257 " -c <n> Do n conversions, or loop forever if n < 0\n"
258 " -e Disable wait for event (new data)\n"
259 " -g Use trigger-less mode\n"
260 " -l <n> Set buffer length to n samples\n"
261 " --device-name -n <name>\n"
262 " --device-num -N <num>\n"
263 " Set device by name or number (mandatory)\n"
264 " --trigger-name -t <name>\n"
265 " --trigger-num -T <num>\n"
266 " Set trigger by name or number\n"
267 " -w <n> Set delay between reads in us (event-less mode)\n");
268 }
269
270 static enum autochan autochannels = AUTOCHANNELS_DISABLED;
271 static char *dev_dir_name = NULL;
272 static char *buf_dir_name = NULL;
273 static bool current_trigger_set = false;
274
cleanup(void)275 static void cleanup(void)
276 {
277 int ret;
278
279 /* Disable trigger */
280 if (dev_dir_name && current_trigger_set) {
281 /* Disconnect the trigger - just write a dummy name. */
282 ret = write_sysfs_string("trigger/current_trigger",
283 dev_dir_name, "NULL");
284 if (ret < 0)
285 fprintf(stderr, "Failed to disable trigger: %s\n",
286 strerror(-ret));
287 current_trigger_set = false;
288 }
289
290 /* Disable buffer */
291 if (buf_dir_name) {
292 ret = write_sysfs_int("enable", buf_dir_name, 0);
293 if (ret < 0)
294 fprintf(stderr, "Failed to disable buffer: %s\n",
295 strerror(-ret));
296 }
297
298 /* Disable channels if auto-enabled */
299 if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
300 ret = enable_disable_all_channels(dev_dir_name, 0);
301 if (ret)
302 fprintf(stderr, "Failed to disable all channels\n");
303 autochannels = AUTOCHANNELS_DISABLED;
304 }
305 }
306
sig_handler(int signum)307 static void sig_handler(int signum)
308 {
309 fprintf(stderr, "Caught signal %d\n", signum);
310 cleanup();
311 exit(-signum);
312 }
313
register_cleanup(void)314 static void register_cleanup(void)
315 {
316 struct sigaction sa = { .sa_handler = sig_handler };
317 const int signums[] = { SIGINT, SIGTERM, SIGABRT };
318 int ret, i;
319
320 for (i = 0; i < ARRAY_SIZE(signums); ++i) {
321 ret = sigaction(signums[i], &sa, NULL);
322 if (ret) {
323 perror("Failed to register signal handler");
324 exit(-1);
325 }
326 }
327 }
328
329 static const struct option longopts[] = {
330 { "device-name", 1, 0, 'n' },
331 { "device-num", 1, 0, 'N' },
332 { "trigger-name", 1, 0, 't' },
333 { "trigger-num", 1, 0, 'T' },
334 { },
335 };
336
main(int argc,char ** argv)337 int main(int argc, char **argv)
338 {
339 long long num_loops = 2;
340 unsigned long timedelay = 1000000;
341 unsigned long buf_len = 128;
342
343 ssize_t i;
344 unsigned long long j;
345 unsigned long toread;
346 int ret, c;
347 int fp = -1;
348
349 int num_channels = 0;
350 char *trigger_name = NULL, *device_name = NULL;
351
352 char *data = NULL;
353 ssize_t read_size;
354 int dev_num = -1, trig_num = -1;
355 char *buffer_access = NULL;
356 unsigned int scan_size;
357 int noevents = 0;
358 int notrigger = 0;
359 char *dummy;
360 bool force_autochannels = false;
361
362 struct iio_channel_info *channels = NULL;
363
364 register_cleanup();
365
366 while ((c = getopt_long(argc, argv, "aAc:egl:n:N:t:T:w:?", longopts,
367 NULL)) != -1) {
368 switch (c) {
369 case 'a':
370 autochannels = AUTOCHANNELS_ENABLED;
371 break;
372 case 'A':
373 autochannels = AUTOCHANNELS_ENABLED;
374 force_autochannels = true;
375 break;
376 case 'c':
377 errno = 0;
378 num_loops = strtoll(optarg, &dummy, 10);
379 if (errno) {
380 ret = -errno;
381 goto error;
382 }
383
384 break;
385 case 'e':
386 noevents = 1;
387 break;
388 case 'g':
389 notrigger = 1;
390 break;
391 case 'l':
392 errno = 0;
393 buf_len = strtoul(optarg, &dummy, 10);
394 if (errno) {
395 ret = -errno;
396 goto error;
397 }
398
399 break;
400 case 'n':
401 device_name = strdup(optarg);
402 break;
403 case 'N':
404 errno = 0;
405 dev_num = strtoul(optarg, &dummy, 10);
406 if (errno) {
407 ret = -errno;
408 goto error;
409 }
410 break;
411 case 't':
412 trigger_name = strdup(optarg);
413 break;
414 case 'T':
415 errno = 0;
416 trig_num = strtoul(optarg, &dummy, 10);
417 if (errno)
418 return -errno;
419 break;
420 case 'w':
421 errno = 0;
422 timedelay = strtoul(optarg, &dummy, 10);
423 if (errno) {
424 ret = -errno;
425 goto error;
426 }
427 break;
428 case '?':
429 print_usage();
430 ret = -1;
431 goto error;
432 }
433 }
434
435 /* Find the device requested */
436 if (dev_num < 0 && !device_name) {
437 fprintf(stderr, "Device not set\n");
438 print_usage();
439 ret = -1;
440 goto error;
441 } else if (dev_num >= 0 && device_name) {
442 fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
443 print_usage();
444 ret = -1;
445 goto error;
446 } else if (dev_num < 0) {
447 dev_num = find_type_by_name(device_name, "iio:device");
448 if (dev_num < 0) {
449 fprintf(stderr, "Failed to find the %s\n", device_name);
450 ret = dev_num;
451 goto error;
452 }
453 }
454 printf("iio device number being used is %d\n", dev_num);
455
456 ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
457 if (ret < 0)
458 return -ENOMEM;
459 /* Fetch device_name if specified by number */
460 if (!device_name) {
461 device_name = malloc(IIO_MAX_NAME_LENGTH);
462 if (!device_name) {
463 ret = -ENOMEM;
464 goto error;
465 }
466 ret = read_sysfs_string("name", dev_dir_name, device_name);
467 if (ret < 0) {
468 fprintf(stderr, "Failed to read name of device %d\n", dev_num);
469 goto error;
470 }
471 }
472
473 if (notrigger) {
474 printf("trigger-less mode selected\n");
475 } else if (trig_num >= 0) {
476 char *trig_dev_name;
477 ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
478 if (ret < 0) {
479 return -ENOMEM;
480 }
481 trigger_name = malloc(IIO_MAX_NAME_LENGTH);
482 ret = read_sysfs_string("name", trig_dev_name, trigger_name);
483 free(trig_dev_name);
484 if (ret < 0) {
485 fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
486 return ret;
487 }
488 printf("iio trigger number being used is %d\n", trig_num);
489 } else {
490 if (!trigger_name) {
491 /*
492 * Build the trigger name. If it is device associated
493 * its name is <device_name>_dev[n] where n matches
494 * the device number found above.
495 */
496 ret = asprintf(&trigger_name,
497 "%s-dev%d", device_name, dev_num);
498 if (ret < 0) {
499 ret = -ENOMEM;
500 goto error;
501 }
502 }
503
504 /* Look for this "-devN" trigger */
505 trig_num = find_type_by_name(trigger_name, "trigger");
506 if (trig_num < 0) {
507 /* OK try the simpler "-trigger" suffix instead */
508 free(trigger_name);
509 ret = asprintf(&trigger_name,
510 "%s-trigger", device_name);
511 if (ret < 0) {
512 ret = -ENOMEM;
513 goto error;
514 }
515 }
516
517 trig_num = find_type_by_name(trigger_name, "trigger");
518 if (trig_num < 0) {
519 fprintf(stderr, "Failed to find the trigger %s\n",
520 trigger_name);
521 ret = trig_num;
522 goto error;
523 }
524
525 printf("iio trigger number being used is %d\n", trig_num);
526 }
527
528 /*
529 * Parse the files in scan_elements to identify what channels are
530 * present
531 */
532 ret = build_channel_array(dev_dir_name, &channels, &num_channels);
533 if (ret) {
534 fprintf(stderr, "Problem reading scan element information\n"
535 "diag %s\n", dev_dir_name);
536 goto error;
537 }
538 if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&
539 !force_autochannels) {
540 fprintf(stderr, "Auto-channels selected but some channels "
541 "are already activated in sysfs\n");
542 fprintf(stderr, "Proceeding without activating any channels\n");
543 }
544
545 if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||
546 (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {
547 fprintf(stderr, "Enabling all channels\n");
548
549 ret = enable_disable_all_channels(dev_dir_name, 1);
550 if (ret) {
551 fprintf(stderr, "Failed to enable all channels\n");
552 goto error;
553 }
554
555 /* This flags that we need to disable the channels again */
556 autochannels = AUTOCHANNELS_ACTIVE;
557
558 ret = build_channel_array(dev_dir_name, &channels,
559 &num_channels);
560 if (ret) {
561 fprintf(stderr, "Problem reading scan element "
562 "information\n"
563 "diag %s\n", dev_dir_name);
564 goto error;
565 }
566 if (!num_channels) {
567 fprintf(stderr, "Still no channels after "
568 "auto-enabling, giving up\n");
569 goto error;
570 }
571 }
572
573 if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
574 fprintf(stderr,
575 "No channels are enabled, we have nothing to scan.\n");
576 fprintf(stderr, "Enable channels manually in "
577 FORMAT_SCAN_ELEMENTS_DIR
578 "/*_en or pass -a to autoenable channels and "
579 "try again.\n", dev_dir_name);
580 ret = -ENOENT;
581 goto error;
582 }
583
584 /*
585 * Construct the directory name for the associated buffer.
586 * As we know that the lis3l02dq has only one buffer this may
587 * be built rather than found.
588 */
589 ret = asprintf(&buf_dir_name,
590 "%siio:device%d/buffer", iio_dir, dev_num);
591 if (ret < 0) {
592 ret = -ENOMEM;
593 goto error;
594 }
595
596 if (!notrigger) {
597 printf("%s %s\n", dev_dir_name, trigger_name);
598 /*
599 * Set the device trigger to be the data ready trigger found
600 * above
601 */
602 ret = write_sysfs_string_and_verify("trigger/current_trigger",
603 dev_dir_name,
604 trigger_name);
605 if (ret < 0) {
606 fprintf(stderr,
607 "Failed to write current_trigger file\n");
608 goto error;
609 }
610 }
611
612 /* Setup ring buffer parameters */
613 ret = write_sysfs_int("length", buf_dir_name, buf_len);
614 if (ret < 0)
615 goto error;
616
617 /* Enable the buffer */
618 ret = write_sysfs_int("enable", buf_dir_name, 1);
619 if (ret < 0) {
620 fprintf(stderr,
621 "Failed to enable buffer: %s\n", strerror(-ret));
622 goto error;
623 }
624
625 scan_size = size_from_channelarray(channels, num_channels);
626
627 size_t total_buf_len = scan_size * buf_len;
628
629 if (scan_size > 0 && total_buf_len / scan_size != buf_len) {
630 ret = -EFAULT;
631 perror("Integer overflow happened when calculate scan_size * buf_len");
632 goto error;
633 }
634
635 data = malloc(total_buf_len);
636 if (!data) {
637 ret = -ENOMEM;
638 goto error;
639 }
640
641 ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
642 if (ret < 0) {
643 ret = -ENOMEM;
644 goto error;
645 }
646
647 /* Attempt to open non blocking the access dev */
648 fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
649 if (fp == -1) { /* TODO: If it isn't there make the node */
650 ret = -errno;
651 fprintf(stderr, "Failed to open %s\n", buffer_access);
652 goto error;
653 }
654
655 for (j = 0; j < num_loops || num_loops < 0; j++) {
656 if (!noevents) {
657 struct pollfd pfd = {
658 .fd = fp,
659 .events = POLLIN,
660 };
661
662 ret = poll(&pfd, 1, -1);
663 if (ret < 0) {
664 ret = -errno;
665 goto error;
666 } else if (ret == 0) {
667 continue;
668 }
669
670 toread = buf_len;
671 } else {
672 usleep(timedelay);
673 toread = 64;
674 }
675
676 read_size = read(fp, data, toread * scan_size);
677 if (read_size < 0) {
678 if (errno == EAGAIN) {
679 fprintf(stderr, "nothing available\n");
680 continue;
681 } else {
682 break;
683 }
684 }
685 for (i = 0; i < read_size / scan_size; i++)
686 process_scan(data + scan_size * i, channels,
687 num_channels);
688 }
689
690 error:
691 cleanup();
692
693 if (fp >= 0 && close(fp) == -1)
694 perror("Failed to close buffer");
695 free(buffer_access);
696 free(data);
697 free(buf_dir_name);
698 for (i = num_channels - 1; i >= 0; i--) {
699 free(channels[i].name);
700 free(channels[i].generic_name);
701 }
702 free(channels);
703 free(trigger_name);
704 free(device_name);
705 free(dev_dir_name);
706
707 return ret;
708 }
709