tools:iio:iio_utils: initialize count during declaration
[deliverable/linux.git] / tools / iio / generic_buffer.c
CommitLineData
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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>
bdcb31d0 22#include <stdlib.h>
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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>
30268a3d 30#include <string.h>
52615d47 31#include <poll.h>
117cf8b7 32#include <endian.h>
bb23378c 33#include <getopt.h>
1bcdfbcf 34#include <inttypes.h>
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35#include "iio_utils.h"
36
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37/**
38 * size_from_channelarray() - calculate the storage size of a scan
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39 * @channels: the channel info array
40 * @num_channels: number of channels
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41 *
42 * Has the side effect of filling the channels[i].location values used
43 * in processing the buffer output.
44 **/
45int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
46{
47 int bytes = 0;
48 int i = 0;
ff39a252 49
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50 while (i < num_channels) {
51 if (bytes % channels[i].bytes == 0)
52 channels[i].location = bytes;
53 else
54 channels[i].location = bytes - bytes%channels[i].bytes
55 + channels[i].bytes;
56 bytes = channels[i].location + channels[i].bytes;
57 i++;
58 }
59 return bytes;
60}
61
8e926134 62void print2byte(uint16_t input, struct iio_channel_info *info)
52615d47 63{
117cf8b7 64 /* First swap if incorrect endian */
117cf8b7 65 if (info->be)
8e926134 66 input = be16toh(input);
117cf8b7 67 else
8e926134 68 input = le16toh(input);
117cf8b7 69
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70 /*
71 * Shift before conversion to avoid sign extension
72 * of left aligned data
73 */
1525ecfc 74 input >>= info->shift;
8e926134 75 input &= info->mask;
52615d47 76 if (info->is_signed) {
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77 int16_t val = (int16_t)(input << (16 - info->bits_used)) >>
78 (16 - info->bits_used);
79 printf("%05f ", ((float)val + info->offset) * info->scale);
80 } else {
81 printf("%05f ", ((float)input + info->offset) * info->scale);
82 }
83}
ff39a252 84
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85void print4byte(uint32_t input, struct iio_channel_info *info)
86{
87 /* First swap if incorrect endian */
88 if (info->be)
89 input = be32toh(input);
90 else
91 input = le32toh(input);
92
93 /*
94 * Shift before conversion to avoid sign extension
95 * of left aligned data
96 */
97 input >>= info->shift;
98 input &= info->mask;
99 if (info->is_signed) {
100 int32_t val = (int32_t)(input << (32 - info->bits_used)) >>
101 (32 - info->bits_used);
102 printf("%05f ", ((float)val + info->offset) * info->scale);
52615d47 103 } else {
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104 printf("%05f ", ((float)input + info->offset) * info->scale);
105 }
106}
ff39a252 107
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108void print8byte(uint64_t input, struct iio_channel_info *info)
109{
110 /* First swap if incorrect endian */
111 if (info->be)
112 input = be64toh(input);
113 else
114 input = le64toh(input);
115
116 /*
117 * Shift before conversion to avoid sign extension
118 * of left aligned data
119 */
120 input >>= info->shift;
121 input &= info->mask;
122 if (info->is_signed) {
123 int64_t val = (int64_t)(input << (64 - info->bits_used)) >>
124 (64 - info->bits_used);
125 /* special case for timestamp */
126 if (info->scale == 1.0f && info->offset == 0.0f)
127 printf("%" PRId64 " ", val);
128 else
129 printf("%05f ",
130 ((float)val + info->offset) * info->scale);
131 } else {
132 printf("%05f ", ((float)input + info->offset) * info->scale);
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133 }
134}
8e926134 135
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136/**
137 * process_scan() - print out the values in SI units
138 * @data: pointer to the start of the scan
d8da0eee 139 * @channels: information about the channels. Note
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140 * size_from_channelarray must have been called first to fill the
141 * location offsets.
d8da0eee 142 * @num_channels: number of channels
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143 **/
144void process_scan(char *data,
d8da0eee 145 struct iio_channel_info *channels,
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146 int num_channels)
147{
148 int k;
ff39a252 149
e58537cc 150 for (k = 0; k < num_channels; k++)
d8da0eee 151 switch (channels[k].bytes) {
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152 /* only a few cases implemented so far */
153 case 2:
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154 print2byte(*(uint16_t *)(data + channels[k].location),
155 &channels[k]);
e58537cc 156 break;
6cffc1f8 157 case 4:
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158 print4byte(*(uint32_t *)(data + channels[k].location),
159 &channels[k]);
6cffc1f8 160 break;
e58537cc 161 case 8:
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162 print8byte(*(uint64_t *)(data + channels[k].location),
163 &channels[k]);
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164 break;
165 default:
166 break;
167 }
168 printf("\n");
169}
170
171int main(int argc, char **argv)
172{
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173 unsigned long num_loops = 2;
174 unsigned long timedelay = 1000000;
175 unsigned long buf_len = 128;
176
e58537cc 177 int ret, c, i, j, toread;
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178 int fp;
179
180 int num_channels;
181 char *trigger_name = NULL, *device_name = NULL;
182 char *dev_dir_name, *buf_dir_name;
183
184 int datardytrigger = 1;
185 char *data;
c77b3810 186 ssize_t read_size;
e58537cc 187 int dev_num, trig_num;
52615d47 188 char *buffer_access;
e58537cc 189 int scan_size;
30268a3d 190 int noevents = 0;
b6d5be57 191 int notrigger = 0;
96df9799 192 char *dummy;
e58537cc 193
d8da0eee 194 struct iio_channel_info *channels;
e58537cc 195
b6d5be57 196 while ((c = getopt(argc, argv, "l:w:c:et:n:g")) != -1) {
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197 switch (c) {
198 case 'n':
199 device_name = optarg;
200 break;
201 case 't':
202 trigger_name = optarg;
203 datardytrigger = 0;
204 break;
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205 case 'e':
206 noevents = 1;
207 break;
96df9799 208 case 'c':
c8ce9903 209 errno = 0;
96df9799 210 num_loops = strtoul(optarg, &dummy, 10);
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211 if (errno)
212 return -errno;
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213 break;
214 case 'w':
c8ce9903 215 errno = 0;
96df9799 216 timedelay = strtoul(optarg, &dummy, 10);
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217 if (errno)
218 return -errno;
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219 break;
220 case 'l':
c8ce9903 221 errno = 0;
96df9799 222 buf_len = strtoul(optarg, &dummy, 10);
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223 if (errno)
224 return -errno;
96df9799 225 break;
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226 case 'g':
227 notrigger = 1;
228 break;
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229 case '?':
230 return -1;
231 }
232 }
233
065896e9
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234 if (device_name == NULL)
235 return -1;
236
e58537cc 237 /* Find the device requested */
1aa04278 238 dev_num = find_type_by_name(device_name, "iio:device");
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239 if (dev_num < 0) {
240 printf("Failed to find the %s\n", device_name);
0e799878 241 return dev_num;
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242 }
243 printf("iio device number being used is %d\n", dev_num);
244
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245 ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
246 if (ret < 0)
247 return -ENOMEM;
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248
249 if (!notrigger) {
250 if (trigger_name == NULL) {
251 /*
252 * Build the trigger name. If it is device associated
253 * its name is <device_name>_dev[n] where n matches
254 * the device number found above.
255 */
256 ret = asprintf(&trigger_name,
257 "%s-dev%d", device_name, dev_num);
258 if (ret < 0) {
259 ret = -ENOMEM;
d3ccfc41 260 goto error_free_dev_dir_name;
b6d5be57 261 }
e58537cc 262 }
e58537cc 263
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264 /* Verify the trigger exists */
265 trig_num = find_type_by_name(trigger_name, "trigger");
266 if (trig_num < 0) {
267 printf("Failed to find the trigger %s\n", trigger_name);
e83a47cf 268 ret = trig_num;
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269 goto error_free_triggername;
270 }
271 printf("iio trigger number being used is %d\n", trig_num);
272 } else
273 printf("trigger-less mode selected\n");
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274
275 /*
276 * Parse the files in scan_elements to identify what channels are
277 * present
278 */
d8da0eee 279 ret = build_channel_array(dev_dir_name, &channels, &num_channels);
e58537cc 280 if (ret) {
52615d47 281 printf("Problem reading scan element information\n");
1aa04278 282 printf("diag %s\n", dev_dir_name);
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283 goto error_free_triggername;
284 }
285
286 /*
287 * Construct the directory name for the associated buffer.
288 * As we know that the lis3l02dq has only one buffer this may
289 * be built rather than found.
290 */
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291 ret = asprintf(&buf_dir_name,
292 "%siio:device%d/buffer", iio_dir, dev_num);
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293 if (ret < 0) {
294 ret = -ENOMEM;
63f05c85 295 goto error_free_channels;
e58537cc 296 }
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297
298 if (!notrigger) {
299 printf("%s %s\n", dev_dir_name, trigger_name);
300 /* Set the device trigger to be the data ready trigger found
301 * above */
302 ret = write_sysfs_string_and_verify("trigger/current_trigger",
303 dev_dir_name,
304 trigger_name);
305 if (ret < 0) {
306 printf("Failed to write current_trigger file\n");
307 goto error_free_buf_dir_name;
308 }
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309 }
310
311 /* Setup ring buffer parameters */
312 ret = write_sysfs_int("length", buf_dir_name, buf_len);
313 if (ret < 0)
314 goto error_free_buf_dir_name;
315
316 /* Enable the buffer */
317 ret = write_sysfs_int("enable", buf_dir_name, 1);
318 if (ret < 0)
319 goto error_free_buf_dir_name;
d8da0eee 320 scan_size = size_from_channelarray(channels, num_channels);
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321 data = malloc(scan_size*buf_len);
322 if (!data) {
323 ret = -ENOMEM;
324 goto error_free_buf_dir_name;
325 }
326
1aa04278 327 ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
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328 if (ret < 0) {
329 ret = -ENOMEM;
330 goto error_free_data;
331 }
332
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333 /* Attempt to open non blocking the access dev */
334 fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
d8da0eee 335 if (fp == -1) { /* If it isn't there make the node */
e58537cc 336 ret = -errno;
2b6a6e67 337 printf("Failed to open %s\n", buffer_access);
52615d47 338 goto error_free_buffer_access;
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JC
339 }
340
341 /* Wait for events 10 times */
342 for (j = 0; j < num_loops; j++) {
30268a3d 343 if (!noevents) {
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344 struct pollfd pfd = {
345 .fd = fp,
346 .events = POLLIN,
347 };
348
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349 ret = poll(&pfd, 1, -1);
350 if (ret < 0) {
351 ret = -errno;
352 goto error_close_buffer_access;
353 } else if (ret == 0) {
354 continue;
355 }
356
52615d47
JC
357 toread = buf_len;
358
30268a3d 359 } else {
96df9799 360 usleep(timedelay);
30268a3d 361 toread = 64;
e58537cc 362 }
30268a3d 363
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JC
364 read_size = read(fp,
365 data,
366 toread*scan_size);
97b603a4 367 if (read_size < 0) {
8749948a 368 if (errno == EAGAIN) {
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369 printf("nothing available\n");
370 continue;
371 } else
372 break;
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373 }
374 for (i = 0; i < read_size/scan_size; i++)
375 process_scan(data + scan_size*i,
d8da0eee 376 channels,
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377 num_channels);
378 }
379
d8da0eee 380 /* Stop the buffer */
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381 ret = write_sysfs_int("enable", buf_dir_name, 0);
382 if (ret < 0)
52615d47 383 goto error_close_buffer_access;
e58537cc 384
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KW
385 if (!notrigger)
386 /* Disconnect the trigger - just write a dummy name. */
6bb7cac8
HK
387 ret = write_sysfs_string("trigger/current_trigger",
388 dev_dir_name, "NULL");
389 if (ret < 0)
390 printf("Failed to write to %s\n", dev_dir_name);
e58537cc 391
e58537cc 392error_close_buffer_access:
6bb7cac8
HK
393 if (close(fp) == -1)
394 perror("Failed to close buffer");
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395error_free_buffer_access:
396 free(buffer_access);
a71bfb4a
HK
397error_free_data:
398 free(data);
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399error_free_buf_dir_name:
400 free(buf_dir_name);
63f05c85
HK
401error_free_channels:
402 for (i = num_channels - 1; i >= 0; i--) {
403 free(channels[i].name);
404 free(channels[i].generic_name);
405 }
406 free(channels);
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JC
407error_free_triggername:
408 if (datardytrigger)
409 free(trigger_name);
d3ccfc41
HK
410error_free_dev_dir_name:
411 free(dev_dir_name);
0e799878 412
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JC
413 return ret;
414}
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