1 /* Industrialio buffer test code.
3 * Copyright (c) 2008 Jonathan Cameron
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.
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
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.
29 #include <linux/types.h>
35 #include "iio_utils.h"
38 * enum autochan - state for the automatic channel enabling mechanism
41 AUTOCHANNELS_DISABLED,
47 * size_from_channelarray() - calculate the storage size of a scan
48 * @channels: the channel info array
49 * @num_channels: number of channels
51 * Has the side effect of filling the channels[i].location values used
52 * in processing the buffer output.
54 int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
59 while (i < num_channels) {
60 if (bytes % channels[i].bytes == 0)
61 channels[i].location = bytes;
63 channels[i].location = bytes - bytes % channels[i].bytes
66 bytes = channels[i].location + channels[i].bytes;
73 void print1byte(uint8_t input, struct iio_channel_info *info)
76 * Shift before conversion to avoid sign extension
77 * of left aligned data
79 input >>= info->shift;
81 if (info->is_signed) {
82 int8_t val = (int8_t)(input << (8 - info->bits_used)) >>
83 (8 - info->bits_used);
84 printf("%05f ", ((float)val + info->offset) * info->scale);
86 printf("%05f ", ((float)input + info->offset) * info->scale);
90 void print2byte(uint16_t input, struct iio_channel_info *info)
92 /* First swap if incorrect endian */
94 input = be16toh(input);
96 input = le16toh(input);
99 * Shift before conversion to avoid sign extension
100 * of left aligned data
102 input >>= info->shift;
104 if (info->is_signed) {
105 int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
106 (16 - info->bits_used);
107 printf("%05f ", ((float)val + info->offset) * info->scale);
109 printf("%05f ", ((float)input + info->offset) * info->scale);
113 void print4byte(uint32_t input, struct iio_channel_info *info)
115 /* First swap if incorrect endian */
117 input = be32toh(input);
119 input = le32toh(input);
122 * Shift before conversion to avoid sign extension
123 * of left aligned data
125 input >>= info->shift;
127 if (info->is_signed) {
128 int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
129 (32 - info->bits_used);
130 printf("%05f ", ((float)val + info->offset) * info->scale);
132 printf("%05f ", ((float)input + info->offset) * info->scale);
136 void print8byte(uint64_t input, struct iio_channel_info *info)
138 /* First swap if incorrect endian */
140 input = be64toh(input);
142 input = le64toh(input);
145 * Shift before conversion to avoid sign extension
146 * of left aligned data
148 input >>= info->shift;
150 if (info->is_signed) {
151 int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
152 (64 - info->bits_used);
153 /* special case for timestamp */
154 if (info->scale == 1.0f && info->offset == 0.0f)
155 printf("%" PRId64 " ", val);
158 ((float)val + info->offset) * info->scale);
160 printf("%05f ", ((float)input + info->offset) * info->scale);
165 * process_scan() - print out the values in SI units
166 * @data: pointer to the start of the scan
167 * @channels: information about the channels.
168 * Note: size_from_channelarray must have been called first
169 * to fill the location offsets.
170 * @num_channels: number of channels
172 void process_scan(char *data,
173 struct iio_channel_info *channels,
178 for (k = 0; k < num_channels; k++)
179 switch (channels[k].bytes) {
180 /* only a few cases implemented so far */
182 print1byte(*(uint8_t *)(data + channels[k].location),
186 print2byte(*(uint16_t *)(data + channels[k].location),
190 print4byte(*(uint32_t *)(data + channels[k].location),
194 print8byte(*(uint64_t *)(data + channels[k].location),
203 static int enable_disable_all_channels(char *dev_dir_name, int enable)
205 const struct dirent *ent;
206 char scanelemdir[256];
210 snprintf(scanelemdir, sizeof(scanelemdir),
211 FORMAT_SCAN_ELEMENTS_DIR, dev_dir_name);
212 scanelemdir[sizeof(scanelemdir)-1] = '\0';
214 dp = opendir(scanelemdir);
216 fprintf(stderr, "Enabling/disabling channels: can't open %s\n",
222 while (ent = readdir(dp), ent) {
223 if (iioutils_check_suffix(ent->d_name, "_en")) {
224 printf("%sabling: %s\n",
225 enable ? "En" : "Dis",
227 ret = write_sysfs_int(ent->d_name, scanelemdir,
230 fprintf(stderr, "Failed to enable/disable %s\n",
235 if (closedir(dp) == -1) {
236 perror("Enabling/disabling channels: "
237 "Failed to close directory");
243 void print_usage(void)
245 fprintf(stderr, "Usage: generic_buffer [options]...\n"
246 "Capture, convert and output data from IIO device buffer\n"
247 " -a Auto-activate all available channels\n"
248 " -c <n> Do n conversions\n"
249 " -e Disable wait for event (new data)\n"
250 " -g Use trigger-less mode\n"
251 " -l <n> Set buffer length to n samples\n"
252 " -n <name> Set device name (mandatory)\n"
253 " -t <name> Set trigger name\n"
254 " -w <n> Set delay between reads in us (event-less mode)\n");
257 int main(int argc, char **argv)
259 unsigned long num_loops = 2;
260 unsigned long timedelay = 1000000;
261 unsigned long buf_len = 128;
263 int ret, c, i, j, toread;
267 char *trigger_name = NULL, *device_name = NULL;
268 char *dev_dir_name, *buf_dir_name;
270 int datardytrigger = 1;
273 int dev_num, trig_num;
278 enum autochan autochannels = AUTOCHANNELS_DISABLED;
281 struct iio_channel_info *channels;
283 while ((c = getopt(argc, argv, "ac:egl:n:t:w:")) != -1) {
286 autochannels = AUTOCHANNELS_ENABLED;
290 num_loops = strtoul(optarg, &dummy, 10);
303 buf_len = strtoul(optarg, &dummy, 10);
309 device_name = optarg;
312 trigger_name = optarg;
317 timedelay = strtoul(optarg, &dummy, 10);
328 fprintf(stderr, "Device name not set\n");
333 /* Find the device requested */
334 dev_num = find_type_by_name(device_name, "iio:device");
336 fprintf(stderr, "Failed to find the %s\n", device_name);
340 printf("iio device number being used is %d\n", dev_num);
342 ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
349 * Build the trigger name. If it is device associated
350 * its name is <device_name>_dev[n] where n matches
351 * the device number found above.
353 ret = asprintf(&trigger_name,
354 "%s-dev%d", device_name, dev_num);
357 goto error_free_dev_dir_name;
361 /* Look for this "-devN" trigger */
362 trig_num = find_type_by_name(trigger_name, "trigger");
364 /* OK try the simpler "-trigger" suffix instead */
366 ret = asprintf(&trigger_name,
367 "%s-trigger", device_name);
370 goto error_free_dev_dir_name;
374 trig_num = find_type_by_name(trigger_name, "trigger");
376 fprintf(stderr, "Failed to find the trigger %s\n",
379 goto error_free_triggername;
382 printf("iio trigger number being used is %d\n", trig_num);
384 printf("trigger-less mode selected\n");
388 * Parse the files in scan_elements to identify what channels are
391 ret = build_channel_array(dev_dir_name, &channels, &num_channels);
393 fprintf(stderr, "Problem reading scan element information\n"
394 "diag %s\n", dev_dir_name);
395 goto error_free_triggername;
397 if (num_channels && autochannels == AUTOCHANNELS_ENABLED) {
398 fprintf(stderr, "Auto-channels selected but some channels "
399 "are already activated in sysfs\n");
400 fprintf(stderr, "Proceeding without activating any channels\n");
403 if (!num_channels && autochannels == AUTOCHANNELS_ENABLED) {
405 "No channels are enabled, enabling all channels\n");
407 ret = enable_disable_all_channels(dev_dir_name, 1);
409 fprintf(stderr, "Failed to enable all channels\n");
410 goto error_free_triggername;
413 /* This flags that we need to disable the channels again */
414 autochannels = AUTOCHANNELS_ACTIVE;
416 ret = build_channel_array(dev_dir_name, &channels,
419 fprintf(stderr, "Problem reading scan element "
421 "diag %s\n", dev_dir_name);
422 goto error_disable_channels;
425 fprintf(stderr, "Still no channels after "
426 "auto-enabling, giving up\n");
427 goto error_disable_channels;
431 if (!num_channels && autochannels == AUTOCHANNELS_DISABLED) {
433 "No channels are enabled, we have nothing to scan.\n");
434 fprintf(stderr, "Enable channels manually in "
435 FORMAT_SCAN_ELEMENTS_DIR
436 "/*_en or pass -a to autoenable channels and "
437 "try again.\n", dev_dir_name);
439 goto error_free_triggername;
443 * Construct the directory name for the associated buffer.
444 * As we know that the lis3l02dq has only one buffer this may
445 * be built rather than found.
447 ret = asprintf(&buf_dir_name,
448 "%siio:device%d/buffer", iio_dir, dev_num);
451 goto error_free_channels;
455 printf("%s %s\n", dev_dir_name, trigger_name);
457 * Set the device trigger to be the data ready trigger found
460 ret = write_sysfs_string_and_verify("trigger/current_trigger",
465 "Failed to write current_trigger file\n");
466 goto error_free_buf_dir_name;
470 /* Setup ring buffer parameters */
471 ret = write_sysfs_int("length", buf_dir_name, buf_len);
473 goto error_free_buf_dir_name;
475 /* Enable the buffer */
476 ret = write_sysfs_int("enable", buf_dir_name, 1);
479 "Failed to enable buffer: %s\n", strerror(-ret));
480 goto error_free_buf_dir_name;
483 scan_size = size_from_channelarray(channels, num_channels);
484 data = malloc(scan_size * buf_len);
487 goto error_free_buf_dir_name;
490 ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
493 goto error_free_data;
496 /* Attempt to open non blocking the access dev */
497 fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
498 if (fp == -1) { /* TODO: If it isn't there make the node */
500 fprintf(stderr, "Failed to open %s\n", buffer_access);
501 goto error_free_buffer_access;
504 for (j = 0; j < num_loops; j++) {
506 struct pollfd pfd = {
511 ret = poll(&pfd, 1, -1);
514 goto error_close_buffer_access;
515 } else if (ret == 0) {
525 read_size = read(fp, data, toread * scan_size);
527 if (errno == EAGAIN) {
528 fprintf(stderr, "nothing available\n");
534 for (i = 0; i < read_size / scan_size; i++)
535 process_scan(data + scan_size * i, channels,
539 /* Stop the buffer */
540 ret = write_sysfs_int("enable", buf_dir_name, 0);
542 goto error_close_buffer_access;
545 /* Disconnect the trigger - just write a dummy name. */
546 ret = write_sysfs_string("trigger/current_trigger",
547 dev_dir_name, "NULL");
549 fprintf(stderr, "Failed to write to %s\n",
552 error_close_buffer_access:
554 perror("Failed to close buffer");
556 error_free_buffer_access:
560 error_free_buf_dir_name:
563 for (i = num_channels - 1; i >= 0; i--) {
564 free(channels[i].name);
565 free(channels[i].generic_name);
568 error_free_triggername:
571 error_disable_channels:
572 if (autochannels == AUTOCHANNELS_ACTIVE) {
573 ret = enable_disable_all_channels(dev_dir_name, 0);
575 fprintf(stderr, "Failed to disable all channels\n");
577 error_free_dev_dir_name: