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 * size_from_channelarray() - calculate the storage size of a scan
39 * @channels: the channel info array
40 * @num_channels: number of channels
42 * Has the side effect of filling the channels[i].location values used
43 * in processing the buffer output.
45 int size_from_channelarray(struct iio_channel_info
*channels
, int num_channels
)
50 while (i
< num_channels
) {
51 if (bytes
% channels
[i
].bytes
== 0)
52 channels
[i
].location
= bytes
;
54 channels
[i
].location
= bytes
- bytes
%channels
[i
].bytes
56 bytes
= channels
[i
].location
+ channels
[i
].bytes
;
62 void print2byte(uint16_t input
, struct iio_channel_info
*info
)
64 /* First swap if incorrect endian */
66 input
= be16toh(input
);
68 input
= le16toh(input
);
71 * Shift before conversion to avoid sign extension
72 * of left aligned data
74 input
>>= info
->shift
;
76 if (info
->is_signed
) {
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
);
81 printf("%05f ", ((float)input
+ info
->offset
) * info
->scale
);
85 void print4byte(uint32_t input
, struct iio_channel_info
*info
)
87 /* First swap if incorrect endian */
89 input
= be32toh(input
);
91 input
= le32toh(input
);
94 * Shift before conversion to avoid sign extension
95 * of left aligned data
97 input
>>= info
->shift
;
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
);
104 printf("%05f ", ((float)input
+ info
->offset
) * info
->scale
);
108 void print8byte(uint64_t input
, struct iio_channel_info
*info
)
110 /* First swap if incorrect endian */
112 input
= be64toh(input
);
114 input
= le64toh(input
);
117 * Shift before conversion to avoid sign extension
118 * of left aligned data
120 input
>>= info
->shift
;
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
);
130 ((float)val
+ info
->offset
) * info
->scale
);
132 printf("%05f ", ((float)input
+ info
->offset
) * info
->scale
);
137 * process_scan() - print out the values in SI units
138 * @data: pointer to the start of the scan
139 * @channels: information about the channels. Note
140 * size_from_channelarray must have been called first to fill the
142 * @num_channels: number of channels
144 void process_scan(char *data
,
145 struct iio_channel_info
*channels
,
150 for (k
= 0; k
< num_channels
; k
++)
151 switch (channels
[k
].bytes
) {
152 /* only a few cases implemented so far */
154 print2byte(*(uint16_t *)(data
+ channels
[k
].location
),
158 print4byte(*(uint32_t *)(data
+ channels
[k
].location
),
162 print8byte(*(uint64_t *)(data
+ channels
[k
].location
),
171 int main(int argc
, char **argv
)
173 unsigned long num_loops
= 2;
174 unsigned long timedelay
= 1000000;
175 unsigned long buf_len
= 128;
177 int ret
, c
, i
, j
, toread
;
181 char *trigger_name
= NULL
, *device_name
= NULL
;
182 char *dev_dir_name
, *buf_dir_name
;
184 int datardytrigger
= 1;
187 int dev_num
, trig_num
;
194 struct iio_channel_info
*channels
;
196 while ((c
= getopt(argc
, argv
, "l:w:c:et:n:g")) != -1) {
199 device_name
= optarg
;
202 trigger_name
= optarg
;
210 num_loops
= strtoul(optarg
, &dummy
, 10);
216 timedelay
= strtoul(optarg
, &dummy
, 10);
222 buf_len
= strtoul(optarg
, &dummy
, 10);
234 if (device_name
== NULL
)
237 /* Find the device requested */
238 dev_num
= find_type_by_name(device_name
, "iio:device");
240 printf("Failed to find the %s\n", device_name
);
243 printf("iio device number being used is %d\n", dev_num
);
245 ret
= asprintf(&dev_dir_name
, "%siio:device%d", iio_dir
, dev_num
);
250 if (trigger_name
== NULL
) {
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.
256 ret
= asprintf(&trigger_name
,
257 "%s-dev%d", device_name
, dev_num
);
260 goto error_free_dev_dir_name
;
264 /* Verify the trigger exists */
265 trig_num
= find_type_by_name(trigger_name
, "trigger");
267 printf("Failed to find the trigger %s\n", trigger_name
);
269 goto error_free_triggername
;
271 printf("iio trigger number being used is %d\n", trig_num
);
273 printf("trigger-less mode selected\n");
276 * Parse the files in scan_elements to identify what channels are
279 ret
= build_channel_array(dev_dir_name
, &channels
, &num_channels
);
281 printf("Problem reading scan element information\n");
282 printf("diag %s\n", dev_dir_name
);
283 goto error_free_triggername
;
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.
291 ret
= asprintf(&buf_dir_name
,
292 "%siio:device%d/buffer", iio_dir
, dev_num
);
295 goto error_free_channels
;
299 printf("%s %s\n", dev_dir_name
, trigger_name
);
300 /* Set the device trigger to be the data ready trigger found
302 ret
= write_sysfs_string_and_verify("trigger/current_trigger",
306 printf("Failed to write current_trigger file\n");
307 goto error_free_buf_dir_name
;
311 /* Setup ring buffer parameters */
312 ret
= write_sysfs_int("length", buf_dir_name
, buf_len
);
314 goto error_free_buf_dir_name
;
316 /* Enable the buffer */
317 ret
= write_sysfs_int("enable", buf_dir_name
, 1);
319 goto error_free_buf_dir_name
;
320 scan_size
= size_from_channelarray(channels
, num_channels
);
321 data
= malloc(scan_size
*buf_len
);
324 goto error_free_buf_dir_name
;
327 ret
= asprintf(&buffer_access
, "/dev/iio:device%d", dev_num
);
330 goto error_free_data
;
333 /* Attempt to open non blocking the access dev */
334 fp
= open(buffer_access
, O_RDONLY
| O_NONBLOCK
);
335 if (fp
== -1) { /* If it isn't there make the node */
337 printf("Failed to open %s\n", buffer_access
);
338 goto error_free_buffer_access
;
341 /* Wait for events 10 times */
342 for (j
= 0; j
< num_loops
; j
++) {
344 struct pollfd pfd
= {
349 ret
= poll(&pfd
, 1, -1);
352 goto error_close_buffer_access
;
353 } else if (ret
== 0) {
368 if (errno
== EAGAIN
) {
369 printf("nothing available\n");
374 for (i
= 0; i
< read_size
/scan_size
; i
++)
375 process_scan(data
+ scan_size
*i
,
380 /* Stop the buffer */
381 ret
= write_sysfs_int("enable", buf_dir_name
, 0);
383 goto error_close_buffer_access
;
386 /* Disconnect the trigger - just write a dummy name. */
387 ret
= write_sysfs_string("trigger/current_trigger",
388 dev_dir_name
, "NULL");
390 printf("Failed to write to %s\n", dev_dir_name
);
392 error_close_buffer_access
:
394 perror("Failed to close buffer");
395 error_free_buffer_access
:
399 error_free_buf_dir_name
:
402 for (i
= num_channels
- 1; i
>= 0; i
--) {
403 free(channels
[i
].name
);
404 free(channels
[i
].generic_name
);
407 error_free_triggername
:
410 error_free_dev_dir_name
: