summaryrefslogtreecommitdiffstats
path: root/tools/iio/iio_generic_buffer.c
blob: 84545666a09c4d05ad643aba1e5f55911fcd5a52 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
/* Industrialio buffer test code.
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is primarily intended as an example application.
 * Reads the current buffer setup from sysfs and starts a short capture
 * from the specified device, pretty printing the result after appropriate
 * conversion.
 *
 * Command line parameters
 * generic_buffer -n <device_name> -t <trigger_name>
 * If trigger name is not specified the program assumes you want a dataready
 * trigger associated with the device and goes looking for it.
 *
 */

#include <unistd.h>
#include <stdlib.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/dir.h>
#include <linux/types.h>
#include <string.h>
#include <poll.h>
#include <endian.h>
#include <getopt.h>
#include <inttypes.h>
#include <stdbool.h>
#include <signal.h>
#include "iio_utils.h"

/**
 * enum autochan - state for the automatic channel enabling mechanism
 */
enum autochan {
	AUTOCHANNELS_DISABLED,
	AUTOCHANNELS_ENABLED,
	AUTOCHANNELS_ACTIVE,
};

/**
 * size_from_channelarray() - calculate the storage size of a scan
 * @channels:		the channel info array
 * @num_channels:	number of channels
 *
 * Has the side effect of filling the channels[i].location values used
 * in processing the buffer output.
 **/
int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
{
	int bytes = 0;
	int i = 0;

	while (i < num_channels) {
		if (bytes % channels[i].bytes == 0)
			channels[i].location = bytes;
		else
			channels[i].location = bytes - bytes % channels[i].bytes
					       + channels[i].bytes;

		bytes = channels[i].location + channels[i].bytes;
		i++;
	}

	return bytes;
}

void print1byte(uint8_t input, struct iio_channel_info *info)
{
	/*
	 * Shift before conversion to avoid sign extension
	 * of left aligned data
	 */
	input >>= info->shift;
	input &= info->mask;
	if (info->is_signed) {
		int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
			     (8 - info->bits_used);
		printf("%05f ", ((float)val + info->offset) * info->scale);
	} else {
		printf("%05f ", ((float)input + info->offset) * info->scale);
	}
}

void print2byte(uint16_t input, struct iio_channel_info *info)
{
	/* First swap if incorrect endian */
	if (info->be)
		input = be16toh(input);
	else
		input = le16toh(input);

	/*
	 * Shift before conversion to avoid sign extension
	 * of left aligned data
	 */
	input >>= info->shift;
	input &= info->mask;
	if (info->is_signed) {
		int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
			      (16 - info->bits_used);
		printf("%05f ", ((float)val + info->offset) * info->scale);
	} else {
		printf("%05f ", ((float)input + info->offset) * info->scale);
	}
}

void print4byte(uint32_t input, struct iio_channel_info *info)
{
	/* First swap if incorrect endian */
	if (info->be)
		input = be32toh(input);
	else
		input = le32toh(input);

	/*
	 * Shift before conversion to avoid sign extension
	 * of left aligned data
	 */
	input >>= info->shift;
	input &= info->mask;
	if (info->is_signed) {
		int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
			      (32 - info->bits_used);
		printf("%05f ", ((float)val + info->offset) * info->scale);
	} else {
		printf("%05f ", ((float)input + info->offset) * info->scale);
	}
}

void print8byte(uint64_t input, struct iio_channel_info *info)
{
	/* First swap if incorrect endian */
	if (info->be)
		input = be64toh(input);
	else
		input = le64toh(input);

	/*
	 * Shift before conversion to avoid sign extension
	 * of left aligned data
	 */
	input >>= info->shift;
	input &= info->mask;
	if (info->is_signed) {
		int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
			      (64 - info->bits_used);
		/* special case for timestamp */
		if (info->scale == 1.0f && info->offset == 0.0f)
			printf("%" PRId64 " ", val);
		else
			printf("%05f ",
			       ((float)val + info->offset) * info->scale);
	} else {
		printf("%05f ", ((float)input + info->offset) * info->scale);
	}
}

/**
 * process_scan() - print out the values in SI units
 * @data:		pointer to the start of the scan
 * @channels:		information about the channels.
 *			Note: size_from_channelarray must have been called first
 *			      to fill the location offsets.
 * @num_channels:	number of channels
 **/
void process_scan(char *data,
		  struct iio_channel_info *channels,
		  int num_channels)
{
	int k;

	for (k = 0; k < num_channels; k++)
		switch (channels[k].bytes) {
			/* only a few cases implemented so far */
		case 1:
			print1byte(*(uint8_t *)(data + channels[k].location),
				   &channels[k]);
			break;
		case 2:
			print2byte(*(uint16_t *)(data + channels[k].location),
				   &channels[k]);
			break;
		case 4:
			print4byte(*(uint32_t *)(data + channels[k].location),
				   &channels[k]);
			break;
		case 8:
			print8byte(*(uint64_t *)(data + channels[k].location),
				   &channels[k]);
			break;
		default:
			break;
		}
	printf("\n");
}

static int enable_disable_all_channels(char *dev_dir_name, int enable)
{
	const struct dirent *ent;
	char scanelemdir[256];
	DIR *dp;
	int ret;

	snprintf(scanelemdir, sizeof(scanelemdir),
		 FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name);
	scanelemdir[sizeof(scanelemdir)-1] = '\0';

	dp = opendir(scanelemdir);
	if (!dp) {
		fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
			scanelemdir);
		return -EIO;
	}

	ret = -ENOENT;
	while (ent = readdir(dp), ent) {
		if (iioutils_check_suffix(ent->d_name, "_en")) {
			printf("%sabling: %s\n",
			       enable ? "En" : "Dis",
			       ent->d_name);
			ret = write_sysfs_int(ent->d_name, scanelemdir,
					      enable);
			if (ret < 0)
				fprintf(stderr, "Failed to enable/disable %s\n",
					ent->d_name);
		}
	}

	if (closedir(dp) == -1) {
		perror("Enabling/disabling channels: "
		       "Failed to close directory");
		return -errno;
	}
	return 0;
}

void print_usage(void)
{
	fprintf(stderr, "Usage: generic_buffer [options]...\n"
		"Capture, convert and output data from IIO device buffer\n"
		"  -a         Auto-activate all available channels\n"
		"  -A         Force-activate ALL channels\n"
		"  -c <n>     Do n conversions, or loop forever if n < 0\n"
		"  -e         Disable wait for event (new data)\n"
		"  -g         Use trigger-less mode\n"
		"  -l <n>     Set buffer length to n samples\n"
		"  --device-name -n <name>\n"
		"  --device-num -N <num>\n"
		"        Set device by name or number (mandatory)\n"
		"  --trigger-name -t <name>\n"
		"  --trigger-num -T <num>\n"
		"        Set trigger by name or number\n"
		"  -w <n>     Set delay between reads in us (event-less mode)\n");
}

enum autochan autochannels = AUTOCHANNELS_DISABLED;
char *dev_dir_name = NULL;
char *buf_dir_name = NULL;
bool current_trigger_set = false;

void cleanup(void)
{
	int ret;

	/* Disable trigger */
	if (dev_dir_name && current_trigger_set) {
		/* Disconnect the trigger - just write a dummy name. */
		ret = write_sysfs_string("trigger/current_trigger",
					 dev_dir_name, "NULL");
		if (ret < 0)
			fprintf(stderr, "Failed to disable trigger: %s\n",
				strerror(-ret));
		current_trigger_set = false;
	}

	/* Disable buffer */
	if (buf_dir_name) {
		ret = write_sysfs_int("enable", buf_dir_name, 0);
		if (ret < 0)
			fprintf(stderr, "Failed to disable buffer: %s\n",
				strerror(-ret));
	}

	/* Disable channels if auto-enabled */
	if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) {
		ret = enable_disable_all_channels(dev_dir_name, 0);
		if (ret)
			fprintf(stderr, "Failed to disable all channels\n");
		autochannels = AUTOCHANNELS_DISABLED;
	}
}

void sig_handler(int signum)
{
	fprintf(stderr, "Caught signal %d\n", signum);
	cleanup();
	exit(-signum);
}

void register_cleanup(void)
{
	struct sigaction sa = { .sa_handler = sig_handler };
	const int signums[] = { SIGINT, SIGTERM, SIGABRT };
	int ret, i;

	for (i = 0; i < ARRAY_SIZE(signums); ++i) {
		ret = sigaction(signums[i], &sa, NULL);
		if (ret) {
			perror("Failed to register signal handler");
			exit(-1);
		}
	}
}

static const struct option longopts[] = {
	{ "device-name",	1, 0, 'n' },
	{ "device-num",		1, 0, 'N' },
	{ "trigger-name",	1, 0, 't' },
	{ "trigger-num",	1, 0, 'T' },
	{ },
};

int main(int argc, char **argv)
{
	long long num_loops = 2;
	unsigned long timedelay = 1000000;
	unsigned long buf_len = 128;

	ssize_t i;
	unsigned long long j;
	unsigned long toread;
	int ret, c;
	int fp = -1;

	int num_channels = 0;
	char *trigger_name = NULL, *device_name = NULL;

	char *data = NULL;
	ssize_t read_size;
	int dev_num = -1, trig_num = -1;
	char *buffer_access = NULL;
	int scan_size;
	int noevents = 0;
	int notrigger = 0;
	char *dummy;
	bool force_autochannels = false;

	struct iio_channel_info *channels = NULL;

	register_cleanup();

	while ((c = getopt_long(argc, argv, "aAc:egl:n:N:t:T:w:?", longopts,
				NULL)) != -1) {
		switch (c) {
		case 'a':
			autochannels = AUTOCHANNELS_ENABLED;
			break;
		case 'A':
			autochannels = AUTOCHANNELS_ENABLED;
			force_autochannels = true;
			break;	
		case 'c':
			errno = 0;
			num_loops = strtoll(optarg, &dummy, 10);
			if (errno) {
				ret = -errno;
				goto error;
			}

			break;
		case 'e':
			noevents = 1;
			break;
		case 'g':
			notrigger = 1;
			break;
		case 'l':
			errno = 0;
			buf_len = strtoul(optarg, &dummy, 10);
			if (errno) {
				ret = -errno;
				goto error;
			}

			break;
		case 'n':
			device_name = strdup(optarg);
			break;
		case 'N':
			errno = 0;
			dev_num = strtoul(optarg, &dummy, 10);
			if (errno) {
				ret = -errno;
				goto error;
			}
			break;
		case 't':
			trigger_name = strdup(optarg);
			break;
		case 'T':
			errno = 0;
			trig_num = strtoul(optarg, &dummy, 10);
			if (errno)
				return -errno;
			break;
		case 'w':
			errno = 0;
			timedelay = strtoul(optarg, &dummy, 10);
			if (errno) {
				ret = -errno;
				goto error;
			}
			break;
		case '?':
			print_usage();
			ret = -1;
			goto error;
		}
	}

	/* Find the device requested */
	if (dev_num < 0 && !device_name) {
		fprintf(stderr, "Device not set\n");
		print_usage();
		ret = -1;
		goto error;
	} else if (dev_num >= 0 && device_name) {
		fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n");
		print_usage();
		ret = -1;
		goto error;
	} else if (dev_num < 0) {
		dev_num = find_type_by_name(device_name, "iio:device");
		if (dev_num < 0) {
			fprintf(stderr, "Failed to find the %s\n", device_name);
			ret = dev_num;
			goto error;
		}
	}
	printf("iio device number being used is %d\n", dev_num);

	ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
	if (ret < 0)
		return -ENOMEM;
	/* Fetch device_name if specified by number */
	if (!device_name) {
		device_name = malloc(IIO_MAX_NAME_LENGTH);
		if (!device_name) {
			ret = -ENOMEM;
			goto error;
		}
		ret = read_sysfs_string("name", dev_dir_name, device_name);
		if (ret < 0) {
			fprintf(stderr, "Failed to read name of device %d\n", dev_num);
			goto error;
		}
	}

	if (notrigger) {
		printf("trigger-less mode selected\n");
	} else if (trig_num >= 0) {
		char *trig_dev_name;
		ret = asprintf(&trig_dev_name, "%strigger%d", iio_dir, trig_num);
		if (ret < 0) {
			return -ENOMEM;
		}
		trigger_name = malloc(IIO_MAX_NAME_LENGTH);
		ret = read_sysfs_string("name", trig_dev_name, trigger_name);
		free(trig_dev_name);
		if (ret < 0) {
			fprintf(stderr, "Failed to read trigger%d name from\n", trig_num);
			return ret;
		}
		printf("iio trigger number being used is %d\n", trig_num);
	} else {
		if (!trigger_name) {
			/*
			 * Build the trigger name. If it is device associated
			 * its name is <device_name>_dev[n] where n matches
			 * the device number found above.
			 */
			ret = asprintf(&trigger_name,
				       "%s-dev%d", device_name, dev_num);
			if (ret < 0) {
				ret = -ENOMEM;
				goto error;
			}
		}

		/* Look for this "-devN" trigger */
		trig_num = find_type_by_name(trigger_name, "trigger");
		if (trig_num < 0) {
			/* OK try the simpler "-trigger" suffix instead */
			free(trigger_name);
			ret = asprintf(&trigger_name,
				       "%s-trigger", device_name);
			if (ret < 0) {
				ret = -ENOMEM;
				goto error;
			}
		}

		trig_num = find_type_by_name(trigger_name, "trigger");
		if (trig_num < 0) {
			fprintf(stderr, "Failed to find the trigger %s\n",
				trigger_name);
			ret = trig_num;
			goto error;
		}

		printf("iio trigger number being used is %d\n", trig_num);
	}

	/*
	 * Parse the files in scan_elements to identify what channels are
	 * present
	 */
	ret = build_channel_array(dev_dir_name, &channels, &num_channels);
	if (ret) {
		fprintf(stderr, "Problem reading scan element information\n"
			"diag %s\n", dev_dir_name);
		goto error;
	}
	if (num_channels && autochannels == AUTOCHANNELS_ENABLED &&
	    !force_autochannels) {
		fprintf(stderr, "Auto-channels selected but some channels "
			"are already activated in sysfs\n");
		fprintf(stderr, "Proceeding without activating any channels\n");
	}

	if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) ||
	    (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) {
		fprintf(stderr, "Enabling all channels\n");

		ret = enable_disable_all_channels(dev_dir_name, 1);
		if (ret) {
			fprintf(stderr, "Failed to enable all channels\n");
			goto error;
		}

		/* This flags that we need to disable the channels again */
		autochannels = AUTOCHANNELS_ACTIVE;

		ret = build_channel_array(dev_dir_name, &channels,
					  &num_channels);
		if (ret) {
			fprintf(stderr, "Problem reading scan element "
				"information\n"
				"diag %s\n", dev_dir_name);
			goto error;
		}
		if (!num_channels) {
			fprintf(stderr, "Still no channels after "
				"auto-enabling, giving up\n");
			goto error;
		}
	}

	if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
		fprintf(stderr,
			"No channels are enabled, we have nothing to scan.\n");
		fprintf(stderr, "Enable channels manually in "
			FORMAT_SCAN_ELEMENTS_DIR
			"/*_en or pass -a to autoenable channels and "
			"try again.\n", dev_dir_name);
		ret = -ENOENT;
		goto error;
	}

	/*
	 * Construct the directory name for the associated buffer.
	 * As we know that the lis3l02dq has only one buffer this may
	 * be built rather than found.
	 */
	ret = asprintf(&buf_dir_name,
		       "%siio:device%d/buffer", iio_dir, dev_num);
	if (ret < 0) {
		ret = -ENOMEM;
		goto error;
	}

	if (!notrigger) {
		printf("%s %s\n", dev_dir_name, trigger_name);
		/*
		 * Set the device trigger to be the data ready trigger found
		 * above
		 */
		ret = write_sysfs_string_and_verify("trigger/current_trigger",
						    dev_dir_name,
						    trigger_name);
		if (ret < 0) {
			fprintf(stderr,
				"Failed to write current_trigger file\n");
			goto error;
		}
	}

	/* Setup ring buffer parameters */
	ret = write_sysfs_int("length", buf_dir_name, buf_len);
	if (ret < 0)
		goto error;

	/* Enable the buffer */
	ret = write_sysfs_int("enable", buf_dir_name, 1);
	if (ret < 0) {
		fprintf(stderr,
			"Failed to enable buffer: %s\n", strerror(-ret));
		goto error;
	}

	scan_size = size_from_channelarray(channels, num_channels);
	data = malloc(scan_size * buf_len);
	if (!data) {
		ret = -ENOMEM;
		goto error;
	}

	ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
	if (ret < 0) {
		ret = -ENOMEM;
		goto error;
	}

	/* Attempt to open non blocking the access dev */
	fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
	if (fp == -1) { /* TODO: If it isn't there make the node */
		ret = -errno;
		fprintf(stderr, "Failed to open %s\n", buffer_access);
		goto error;
	}

	for (j = 0; j < num_loops || num_loops < 0; j++) {
		if (!noevents) {
			struct pollfd pfd = {
				.fd = fp,
				.events = POLLIN,
			};

			ret = poll(&pfd, 1, -1);
			if (ret < 0) {
				ret = -errno;
				goto error;
			} else if (ret == 0) {
				continue;
			}

			toread = buf_len;
		} else {
			usleep(timedelay);
			toread = 64;
		}

		read_size = read(fp, data, toread * scan_size);
		if (read_size < 0) {
			if (errno == EAGAIN) {
				fprintf(stderr, "nothing available\n");
				continue;
			} else {
				break;
			}
		}
		for (i = 0; i < read_size / scan_size; i++)
			process_scan(data + scan_size * i, channels,
				     num_channels);
	}

error:
	cleanup();

	if (fp >= 0 && close(fp) == -1)
		perror("Failed to close buffer");
	free(buffer_access);
	free(data);
	free(buf_dir_name);
	for (i = num_channels - 1; i >= 0; i--) {
		free(channels[i].name);
		free(channels[i].generic_name);
	}
	free(channels);
	free(trigger_name);
	free(device_name);
	free(dev_dir_name);

	return ret;
}
OpenPOWER on IntegriCloud