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v4.10.11
 
  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}
v5.4
  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}