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 <sys/ioctl.h> |
34 | #include <linux/iio/buffer.h> |
35 | #include "iio_utils.h" |
36 | |
37 | /** |
38 | * enum autochan - state for the automatic channel enabling mechanism |
39 | */ |
40 | enum autochan { |
41 | AUTOCHANNELS_DISABLED, |
42 | AUTOCHANNELS_ENABLED, |
43 | AUTOCHANNELS_ACTIVE, |
44 | }; |
45 | |
46 | /** |
47 | * size_from_channelarray() - calculate the storage size of a scan |
48 | * @channels: the channel info array |
49 | * @num_channels: number of channels |
50 | * |
51 | * Has the side effect of filling the channels[i].location values used |
52 | * in processing the buffer output. |
53 | **/ |
54 | static unsigned int size_from_channelarray(struct iio_channel_info *channels, int num_channels) |
55 | { |
56 | unsigned int bytes = 0; |
57 | int i = 0, max = 0; |
58 | unsigned int misalignment; |
59 | |
60 | while (i < num_channels) { |
61 | if (channels[i].bytes > max) |
62 | max = channels[i].bytes; |
63 | if (bytes % channels[i].bytes == 0) |
64 | channels[i].location = bytes; |
65 | else |
66 | channels[i].location = bytes - bytes % channels[i].bytes |
67 | + channels[i].bytes; |
68 | |
69 | bytes = channels[i].location + channels[i].bytes; |
70 | i++; |
71 | } |
72 | /* |
73 | * We want the data in next sample to also be properly aligned so |
74 | * we'll add padding at the end if needed. Adding padding only |
75 | * works for channel data which size is 2^n bytes. |
76 | */ |
77 | misalignment = bytes % max; |
78 | if (misalignment) |
79 | bytes += max - misalignment; |
80 | |
81 | return bytes; |
82 | } |
83 | |
84 | static void print1byte(uint8_t input, struct iio_channel_info *info) |
85 | { |
86 | /* |
87 | * Shift before conversion to avoid sign extension |
88 | * of left aligned data |
89 | */ |
90 | input >>= info->shift; |
91 | input &= info->mask; |
92 | if (info->is_signed) { |
93 | int8_t val = (int8_t)(input << (8 - info->bits_used)) >> |
94 | (8 - info->bits_used); |
95 | printf("%05f " , ((float)val + info->offset) * info->scale); |
96 | } else { |
97 | printf("%05f " , ((float)input + info->offset) * info->scale); |
98 | } |
99 | } |
100 | |
101 | static void print2byte(uint16_t input, struct iio_channel_info *info) |
102 | { |
103 | /* First swap if incorrect endian */ |
104 | if (info->be) |
105 | input = be16toh(input); |
106 | else |
107 | input = le16toh(input); |
108 | |
109 | /* |
110 | * Shift before conversion to avoid sign extension |
111 | * of left aligned data |
112 | */ |
113 | input >>= info->shift; |
114 | input &= info->mask; |
115 | if (info->is_signed) { |
116 | int16_t val = (int16_t)(input << (16 - info->bits_used)) >> |
117 | (16 - info->bits_used); |
118 | printf("%05f " , ((float)val + info->offset) * info->scale); |
119 | } else { |
120 | printf("%05f " , ((float)input + info->offset) * info->scale); |
121 | } |
122 | } |
123 | |
124 | static void print4byte(uint32_t input, struct iio_channel_info *info) |
125 | { |
126 | /* First swap if incorrect endian */ |
127 | if (info->be) |
128 | input = be32toh(input); |
129 | else |
130 | input = le32toh(input); |
131 | |
132 | /* |
133 | * Shift before conversion to avoid sign extension |
134 | * of left aligned data |
135 | */ |
136 | input >>= info->shift; |
137 | input &= info->mask; |
138 | if (info->is_signed) { |
139 | int32_t val = (int32_t)(input << (32 - info->bits_used)) >> |
140 | (32 - info->bits_used); |
141 | printf("%05f " , ((float)val + info->offset) * info->scale); |
142 | } else { |
143 | printf("%05f " , ((float)input + info->offset) * info->scale); |
144 | } |
145 | } |
146 | |
147 | static void print8byte(uint64_t input, struct iio_channel_info *info) |
148 | { |
149 | /* First swap if incorrect endian */ |
150 | if (info->be) |
151 | input = be64toh(input); |
152 | else |
153 | input = le64toh(input); |
154 | |
155 | /* |
156 | * Shift before conversion to avoid sign extension |
157 | * of left aligned data |
158 | */ |
159 | input >>= info->shift; |
160 | input &= info->mask; |
161 | if (info->is_signed) { |
162 | int64_t val = (int64_t)(input << (64 - info->bits_used)) >> |
163 | (64 - info->bits_used); |
164 | /* special case for timestamp */ |
165 | if (info->scale == 1.0f && info->offset == 0.0f) |
166 | printf("%" PRId64 " " , val); |
167 | else |
168 | printf("%05f " , |
169 | ((float)val + info->offset) * info->scale); |
170 | } else { |
171 | printf("%05f " , ((float)input + info->offset) * info->scale); |
172 | } |
173 | } |
174 | |
175 | /** |
176 | * process_scan() - print out the values in SI units |
177 | * @data: pointer to the start of the scan |
178 | * @channels: information about the channels. |
179 | * Note: size_from_channelarray must have been called first |
180 | * to fill the location offsets. |
181 | * @num_channels: number of channels |
182 | **/ |
183 | static void process_scan(char *data, struct iio_channel_info *channels, |
184 | int num_channels) |
185 | { |
186 | int k; |
187 | |
188 | for (k = 0; k < num_channels; k++) |
189 | switch (channels[k].bytes) { |
190 | /* only a few cases implemented so far */ |
191 | case 1: |
192 | print1byte(input: *(uint8_t *)(data + channels[k].location), |
193 | info: &channels[k]); |
194 | break; |
195 | case 2: |
196 | print2byte(input: *(uint16_t *)(data + channels[k].location), |
197 | info: &channels[k]); |
198 | break; |
199 | case 4: |
200 | print4byte(input: *(uint32_t *)(data + channels[k].location), |
201 | info: &channels[k]); |
202 | break; |
203 | case 8: |
204 | print8byte(input: *(uint64_t *)(data + channels[k].location), |
205 | info: &channels[k]); |
206 | break; |
207 | default: |
208 | break; |
209 | } |
210 | printf("\n" ); |
211 | } |
212 | |
213 | static int enable_disable_all_channels(char *dev_dir_name, int buffer_idx, int enable) |
214 | { |
215 | const struct dirent *ent; |
216 | char scanelemdir[256]; |
217 | DIR *dp; |
218 | int ret; |
219 | |
220 | snprintf(buf: scanelemdir, size: sizeof(scanelemdir), |
221 | FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name, buffer_idx); |
222 | scanelemdir[sizeof(scanelemdir)-1] = '\0'; |
223 | |
224 | dp = opendir(scanelemdir); |
225 | if (!dp) { |
226 | fprintf(stderr, "Enabling/disabling channels: can't open %s\n" , |
227 | scanelemdir); |
228 | return -EIO; |
229 | } |
230 | |
231 | ret = -ENOENT; |
232 | while (ent = readdir(dp), ent) { |
233 | if (iioutils_check_suffix(str: ent->d_name, suffix: "_en" )) { |
234 | printf("%sabling: %s\n" , |
235 | enable ? "En" : "Dis" , |
236 | ent->d_name); |
237 | ret = write_sysfs_int(filename: ent->d_name, basedir: scanelemdir, |
238 | val: enable); |
239 | if (ret < 0) |
240 | fprintf(stderr, "Failed to enable/disable %s\n" , |
241 | ent->d_name); |
242 | } |
243 | } |
244 | |
245 | if (closedir(dp) == -1) { |
246 | perror("Enabling/disabling channels: " |
247 | "Failed to close directory" ); |
248 | return -errno; |
249 | } |
250 | return 0; |
251 | } |
252 | |
253 | static void print_usage(void) |
254 | { |
255 | fprintf(stderr, "Usage: generic_buffer [options]...\n" |
256 | "Capture, convert and output data from IIO device buffer\n" |
257 | " -a Auto-activate all available channels\n" |
258 | " -A Force-activate ALL channels\n" |
259 | " -b <n> The buffer which to open (by index), default 0\n" |
260 | " -c <n> Do n conversions, or loop forever if n < 0\n" |
261 | " -e Disable wait for event (new data)\n" |
262 | " -g Use trigger-less mode\n" |
263 | " -l <n> Set buffer length to n samples\n" |
264 | " --device-name -n <name>\n" |
265 | " --device-num -N <num>\n" |
266 | " Set device by name or number (mandatory)\n" |
267 | " --trigger-name -t <name>\n" |
268 | " --trigger-num -T <num>\n" |
269 | " Set trigger by name or number\n" |
270 | " -w <n> Set delay between reads in us (event-less mode)\n" ); |
271 | } |
272 | |
273 | static enum autochan autochannels = AUTOCHANNELS_DISABLED; |
274 | static char *dev_dir_name = NULL; |
275 | static char *buf_dir_name = NULL; |
276 | static int buffer_idx = 0; |
277 | static bool current_trigger_set = false; |
278 | |
279 | static void cleanup(void) |
280 | { |
281 | int ret; |
282 | |
283 | /* Disable trigger */ |
284 | if (dev_dir_name && current_trigger_set) { |
285 | /* Disconnect the trigger - just write a dummy name. */ |
286 | ret = write_sysfs_string(filename: "trigger/current_trigger" , |
287 | basedir: dev_dir_name, val: "NULL" ); |
288 | if (ret < 0) |
289 | fprintf(stderr, "Failed to disable trigger: %s\n" , |
290 | strerror(-ret)); |
291 | current_trigger_set = false; |
292 | } |
293 | |
294 | /* Disable buffer */ |
295 | if (buf_dir_name) { |
296 | ret = write_sysfs_int(filename: "enable" , basedir: buf_dir_name, val: 0); |
297 | if (ret < 0) |
298 | fprintf(stderr, "Failed to disable buffer: %s\n" , |
299 | strerror(-ret)); |
300 | } |
301 | |
302 | /* Disable channels if auto-enabled */ |
303 | if (dev_dir_name && autochannels == AUTOCHANNELS_ACTIVE) { |
304 | ret = enable_disable_all_channels(dev_dir_name, buffer_idx, enable: 0); |
305 | if (ret) |
306 | fprintf(stderr, "Failed to disable all channels\n" ); |
307 | autochannels = AUTOCHANNELS_DISABLED; |
308 | } |
309 | } |
310 | |
311 | static void sig_handler(int signum) |
312 | { |
313 | fprintf(stderr, "Caught signal %d\n" , signum); |
314 | cleanup(); |
315 | exit(-signum); |
316 | } |
317 | |
318 | static void register_cleanup(void) |
319 | { |
320 | struct sigaction sa = { .sa_handler = sig_handler }; |
321 | const int signums[] = { SIGINT, SIGTERM, SIGABRT }; |
322 | int ret, i; |
323 | |
324 | for (i = 0; i < ARRAY_SIZE(signums); ++i) { |
325 | ret = sigaction(signums[i], &sa, NULL); |
326 | if (ret) { |
327 | perror("Failed to register signal handler" ); |
328 | exit(-1); |
329 | } |
330 | } |
331 | } |
332 | |
333 | static const struct option longopts[] = { |
334 | { "device-name" , 1, 0, 'n' }, |
335 | { "device-num" , 1, 0, 'N' }, |
336 | { "trigger-name" , 1, 0, 't' }, |
337 | { "trigger-num" , 1, 0, 'T' }, |
338 | { }, |
339 | }; |
340 | |
341 | int main(int argc, char **argv) |
342 | { |
343 | long long num_loops = 2; |
344 | unsigned long timedelay = 1000000; |
345 | unsigned long buf_len = 128; |
346 | |
347 | ssize_t i; |
348 | unsigned long long j; |
349 | unsigned long toread; |
350 | int ret, c; |
351 | struct stat st; |
352 | int fd = -1; |
353 | int buf_fd = -1; |
354 | |
355 | int num_channels = 0; |
356 | char *trigger_name = NULL, *device_name = NULL; |
357 | |
358 | char *data = NULL; |
359 | ssize_t read_size; |
360 | int dev_num = -1, trig_num = -1; |
361 | char *buffer_access = NULL; |
362 | unsigned int scan_size; |
363 | int noevents = 0; |
364 | int notrigger = 0; |
365 | char *dummy; |
366 | bool force_autochannels = false; |
367 | |
368 | struct iio_channel_info *channels = NULL; |
369 | |
370 | register_cleanup(); |
371 | |
372 | while ((c = getopt_long(argc, argv, "aAb:c:egl:n:N:t:T:w:?" , longopts, |
373 | NULL)) != -1) { |
374 | switch (c) { |
375 | case 'a': |
376 | autochannels = AUTOCHANNELS_ENABLED; |
377 | break; |
378 | case 'A': |
379 | autochannels = AUTOCHANNELS_ENABLED; |
380 | force_autochannels = true; |
381 | break; |
382 | case 'b': |
383 | errno = 0; |
384 | buffer_idx = strtoll(optarg, &dummy, 10); |
385 | if (errno) { |
386 | ret = -errno; |
387 | goto error; |
388 | } |
389 | if (buffer_idx < 0) { |
390 | ret = -ERANGE; |
391 | goto error; |
392 | } |
393 | |
394 | break; |
395 | case 'c': |
396 | errno = 0; |
397 | num_loops = strtoll(optarg, &dummy, 10); |
398 | if (errno) { |
399 | ret = -errno; |
400 | goto error; |
401 | } |
402 | |
403 | break; |
404 | case 'e': |
405 | noevents = 1; |
406 | break; |
407 | case 'g': |
408 | notrigger = 1; |
409 | break; |
410 | case 'l': |
411 | errno = 0; |
412 | buf_len = strtoul(optarg, &dummy, 10); |
413 | if (errno) { |
414 | ret = -errno; |
415 | goto error; |
416 | } |
417 | |
418 | break; |
419 | case 'n': |
420 | device_name = strdup(optarg); |
421 | break; |
422 | case 'N': |
423 | errno = 0; |
424 | dev_num = strtoul(optarg, &dummy, 10); |
425 | if (errno) { |
426 | ret = -errno; |
427 | goto error; |
428 | } |
429 | break; |
430 | case 't': |
431 | trigger_name = strdup(optarg); |
432 | break; |
433 | case 'T': |
434 | errno = 0; |
435 | trig_num = strtoul(optarg, &dummy, 10); |
436 | if (errno) |
437 | return -errno; |
438 | break; |
439 | case 'w': |
440 | errno = 0; |
441 | timedelay = strtoul(optarg, &dummy, 10); |
442 | if (errno) { |
443 | ret = -errno; |
444 | goto error; |
445 | } |
446 | break; |
447 | case '?': |
448 | print_usage(); |
449 | ret = -1; |
450 | goto error; |
451 | } |
452 | } |
453 | |
454 | /* Find the device requested */ |
455 | if (dev_num < 0 && !device_name) { |
456 | fprintf(stderr, "Device not set\n" ); |
457 | print_usage(); |
458 | ret = -1; |
459 | goto error; |
460 | } else if (dev_num >= 0 && device_name) { |
461 | fprintf(stderr, "Only one of --device-num or --device-name needs to be set\n" ); |
462 | print_usage(); |
463 | ret = -1; |
464 | goto error; |
465 | } else if (dev_num < 0) { |
466 | dev_num = find_type_by_name(name: device_name, type: "iio:device" ); |
467 | if (dev_num < 0) { |
468 | fprintf(stderr, "Failed to find the %s\n" , device_name); |
469 | ret = dev_num; |
470 | goto error; |
471 | } |
472 | } |
473 | printf("iio device number being used is %d\n" , dev_num); |
474 | |
475 | ret = asprintf(&dev_dir_name, "%siio:device%d" , iio_dir, dev_num); |
476 | if (ret < 0) |
477 | return -ENOMEM; |
478 | /* Fetch device_name if specified by number */ |
479 | if (!device_name) { |
480 | device_name = malloc(IIO_MAX_NAME_LENGTH); |
481 | if (!device_name) { |
482 | ret = -ENOMEM; |
483 | goto error; |
484 | } |
485 | ret = read_sysfs_string(filename: "name" , basedir: dev_dir_name, str: device_name); |
486 | if (ret < 0) { |
487 | fprintf(stderr, "Failed to read name of device %d\n" , dev_num); |
488 | goto error; |
489 | } |
490 | } |
491 | |
492 | if (notrigger) { |
493 | printf("trigger-less mode selected\n" ); |
494 | } else if (trig_num >= 0) { |
495 | char *trig_dev_name; |
496 | ret = asprintf(&trig_dev_name, "%strigger%d" , iio_dir, trig_num); |
497 | if (ret < 0) { |
498 | return -ENOMEM; |
499 | } |
500 | trigger_name = malloc(IIO_MAX_NAME_LENGTH); |
501 | ret = read_sysfs_string(filename: "name" , basedir: trig_dev_name, str: trigger_name); |
502 | free(trig_dev_name); |
503 | if (ret < 0) { |
504 | fprintf(stderr, "Failed to read trigger%d name from\n" , trig_num); |
505 | return ret; |
506 | } |
507 | printf("iio trigger number being used is %d\n" , trig_num); |
508 | } else { |
509 | if (!trigger_name) { |
510 | /* |
511 | * Build the trigger name. If it is device associated |
512 | * its name is <device_name>_dev[n] where n matches |
513 | * the device number found above. |
514 | */ |
515 | ret = asprintf(&trigger_name, |
516 | "%s-dev%d" , device_name, dev_num); |
517 | if (ret < 0) { |
518 | ret = -ENOMEM; |
519 | goto error; |
520 | } |
521 | } |
522 | |
523 | /* Look for this "-devN" trigger */ |
524 | trig_num = find_type_by_name(name: trigger_name, type: "trigger" ); |
525 | if (trig_num < 0) { |
526 | /* OK try the simpler "-trigger" suffix instead */ |
527 | free(trigger_name); |
528 | ret = asprintf(&trigger_name, |
529 | "%s-trigger" , device_name); |
530 | if (ret < 0) { |
531 | ret = -ENOMEM; |
532 | goto error; |
533 | } |
534 | } |
535 | |
536 | trig_num = find_type_by_name(name: trigger_name, type: "trigger" ); |
537 | if (trig_num < 0) { |
538 | fprintf(stderr, "Failed to find the trigger %s\n" , |
539 | trigger_name); |
540 | ret = trig_num; |
541 | goto error; |
542 | } |
543 | |
544 | printf("iio trigger number being used is %d\n" , trig_num); |
545 | } |
546 | |
547 | /* |
548 | * Parse the files in scan_elements to identify what channels are |
549 | * present |
550 | */ |
551 | ret = build_channel_array(device_dir: dev_dir_name, buffer_idx, ci_array: &channels, counter: &num_channels); |
552 | if (ret) { |
553 | fprintf(stderr, "Problem reading scan element information\n" |
554 | "diag %s\n" , dev_dir_name); |
555 | goto error; |
556 | } |
557 | if (num_channels && autochannels == AUTOCHANNELS_ENABLED && |
558 | !force_autochannels) { |
559 | fprintf(stderr, "Auto-channels selected but some channels " |
560 | "are already activated in sysfs\n" ); |
561 | fprintf(stderr, "Proceeding without activating any channels\n" ); |
562 | } |
563 | |
564 | if ((!num_channels && autochannels == AUTOCHANNELS_ENABLED) || |
565 | (autochannels == AUTOCHANNELS_ENABLED && force_autochannels)) { |
566 | fprintf(stderr, "Enabling all channels\n" ); |
567 | |
568 | ret = enable_disable_all_channels(dev_dir_name, buffer_idx, enable: 1); |
569 | if (ret) { |
570 | fprintf(stderr, "Failed to enable all channels\n" ); |
571 | goto error; |
572 | } |
573 | |
574 | /* This flags that we need to disable the channels again */ |
575 | autochannels = AUTOCHANNELS_ACTIVE; |
576 | |
577 | ret = build_channel_array(device_dir: dev_dir_name, buffer_idx, ci_array: &channels, |
578 | counter: &num_channels); |
579 | if (ret) { |
580 | fprintf(stderr, "Problem reading scan element " |
581 | "information\n" |
582 | "diag %s\n" , dev_dir_name); |
583 | goto error; |
584 | } |
585 | if (!num_channels) { |
586 | fprintf(stderr, "Still no channels after " |
587 | "auto-enabling, giving up\n" ); |
588 | goto error; |
589 | } |
590 | } |
591 | |
592 | if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) { |
593 | fprintf(stderr, |
594 | "No channels are enabled, we have nothing to scan.\n" ); |
595 | fprintf(stderr, "Enable channels manually in " |
596 | FORMAT_SCAN_ELEMENTS_DIR |
597 | "/*_en or pass -a to autoenable channels and " |
598 | "try again.\n" , dev_dir_name, buffer_idx); |
599 | ret = -ENOENT; |
600 | goto error; |
601 | } |
602 | |
603 | /* |
604 | * Construct the directory name for the associated buffer. |
605 | * As we know that the lis3l02dq has only one buffer this may |
606 | * be built rather than found. |
607 | */ |
608 | ret = asprintf(&buf_dir_name, |
609 | "%siio:device%d/buffer%d" , iio_dir, dev_num, buffer_idx); |
610 | if (ret < 0) { |
611 | ret = -ENOMEM; |
612 | goto error; |
613 | } |
614 | |
615 | if (stat(buf_dir_name, &st)) { |
616 | fprintf(stderr, "Could not stat() '%s', got error %d: %s\n" , |
617 | buf_dir_name, errno, strerror(errno)); |
618 | ret = -errno; |
619 | goto error; |
620 | } |
621 | |
622 | if (!S_ISDIR(st.st_mode)) { |
623 | fprintf(stderr, "File '%s' is not a directory\n" , buf_dir_name); |
624 | ret = -EFAULT; |
625 | goto error; |
626 | } |
627 | |
628 | if (!notrigger) { |
629 | printf("%s %s\n" , dev_dir_name, trigger_name); |
630 | /* |
631 | * Set the device trigger to be the data ready trigger found |
632 | * above |
633 | */ |
634 | ret = write_sysfs_string_and_verify(filename: "trigger/current_trigger" , |
635 | basedir: dev_dir_name, |
636 | val: trigger_name); |
637 | if (ret < 0) { |
638 | fprintf(stderr, |
639 | "Failed to write current_trigger file\n" ); |
640 | goto error; |
641 | } |
642 | } |
643 | |
644 | ret = asprintf(&buffer_access, "/dev/iio:device%d" , dev_num); |
645 | if (ret < 0) { |
646 | ret = -ENOMEM; |
647 | goto error; |
648 | } |
649 | |
650 | /* Attempt to open non blocking the access dev */ |
651 | fd = open(buffer_access, O_RDONLY | O_NONBLOCK); |
652 | if (fd == -1) { /* TODO: If it isn't there make the node */ |
653 | ret = -errno; |
654 | fprintf(stderr, "Failed to open %s\n" , buffer_access); |
655 | goto error; |
656 | } |
657 | |
658 | /* specify for which buffer index we want an FD */ |
659 | buf_fd = buffer_idx; |
660 | |
661 | ret = ioctl(fd, IIO_BUFFER_GET_FD_IOCTL, &buf_fd); |
662 | if (ret == -1 || buf_fd == -1) { |
663 | ret = -errno; |
664 | if (ret == -ENODEV || ret == -EINVAL) |
665 | fprintf(stderr, |
666 | "Device does not have this many buffers\n" ); |
667 | else |
668 | fprintf(stderr, "Failed to retrieve buffer fd\n" ); |
669 | |
670 | goto error; |
671 | } |
672 | |
673 | /* Setup ring buffer parameters */ |
674 | ret = write_sysfs_int(filename: "length" , basedir: buf_dir_name, val: buf_len); |
675 | if (ret < 0) |
676 | goto error; |
677 | |
678 | /* Enable the buffer */ |
679 | ret = write_sysfs_int(filename: "enable" , basedir: buf_dir_name, val: 1); |
680 | if (ret < 0) { |
681 | fprintf(stderr, |
682 | "Failed to enable buffer '%s': %s\n" , |
683 | buf_dir_name, strerror(-ret)); |
684 | goto error; |
685 | } |
686 | |
687 | scan_size = size_from_channelarray(channels, num_channels); |
688 | |
689 | size_t total_buf_len = scan_size * buf_len; |
690 | |
691 | if (scan_size > 0 && total_buf_len / scan_size != buf_len) { |
692 | ret = -EFAULT; |
693 | perror("Integer overflow happened when calculate scan_size * buf_len" ); |
694 | goto error; |
695 | } |
696 | |
697 | data = malloc(total_buf_len); |
698 | if (!data) { |
699 | ret = -ENOMEM; |
700 | goto error; |
701 | } |
702 | |
703 | /** |
704 | * This check is being done here for sanity reasons, however it |
705 | * should be omitted under normal operation. |
706 | * If this is buffer0, we check that we get EBUSY after this point. |
707 | */ |
708 | if (buffer_idx == 0) { |
709 | errno = 0; |
710 | read_size = read(fd, data, 1); |
711 | if (read_size > -1 || errno != EBUSY) { |
712 | ret = -EFAULT; |
713 | perror("Reading from '%s' should not be possible after ioctl()" ); |
714 | goto error; |
715 | } |
716 | } |
717 | |
718 | /* close now the main chardev FD and let the buffer FD work */ |
719 | if (close(fd) == -1) |
720 | perror("Failed to close character device file" ); |
721 | fd = -1; |
722 | |
723 | for (j = 0; j < num_loops || num_loops < 0; j++) { |
724 | if (!noevents) { |
725 | struct pollfd pfd = { |
726 | .fd = buf_fd, |
727 | .events = POLLIN, |
728 | }; |
729 | |
730 | ret = poll(&pfd, 1, -1); |
731 | if (ret < 0) { |
732 | ret = -errno; |
733 | goto error; |
734 | } else if (ret == 0) { |
735 | continue; |
736 | } |
737 | |
738 | } else { |
739 | usleep(timedelay); |
740 | } |
741 | |
742 | toread = buf_len; |
743 | |
744 | read_size = read(buf_fd, data, toread * scan_size); |
745 | if (read_size < 0) { |
746 | if (errno == EAGAIN) { |
747 | fprintf(stderr, "nothing available\n" ); |
748 | continue; |
749 | } else { |
750 | break; |
751 | } |
752 | } |
753 | for (i = 0; i < read_size / scan_size; i++) |
754 | process_scan(data: data + scan_size * i, channels, |
755 | num_channels); |
756 | } |
757 | |
758 | error: |
759 | cleanup(); |
760 | |
761 | if (fd >= 0 && close(fd) == -1) |
762 | perror("Failed to close character device" ); |
763 | if (buf_fd >= 0 && close(buf_fd) == -1) |
764 | perror("Failed to close buffer" ); |
765 | free(buffer_access); |
766 | free(data); |
767 | free(buf_dir_name); |
768 | for (i = num_channels - 1; i >= 0; i--) { |
769 | free(channels[i].name); |
770 | free(channels[i].generic_name); |
771 | } |
772 | free(channels); |
773 | free(trigger_name); |
774 | free(device_name); |
775 | free(dev_dir_name); |
776 | |
777 | return ret; |
778 | } |
779 | |