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/* Industrialio test ring buffer with a lis3l02dq acceleromter
*
* Copyright (c) 2008 Jonathan Cameron
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* Assumes suitable udev rules are used to create the dev nodes as named here.
*/
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/dir.h>
#include <linux/types.h>
#include <dirent.h>
#include "iio_util.h"
static const char *ring_access = "/dev/iio/lis3l02dq_ring_access";
static const char *ring_event = "/dev/iio/lis3l02dq_ring_event";
static const char *device_name = "lis3l02dq";
static const char *trigger_name = "lis3l02dq-dev0";
static int NumVals = 3;
static int scan_ts = 1;
static int RingLength = 128;
/*
* Could get this from ring bps, but only after starting the ring
* which is a bit late for it to be useful
*/
int size_from_scanmode(int numVals, int timestamp)
{
if (numVals && timestamp)
return 16;
else if (timestamp)
return 8;
else
return numVals*2;
}
int main(int argc, char **argv)
{
int i, j, k, toread;
FILE *fp_ev;
int fp;
char *data;
size_t read_size;
struct iio_event_data dat;
char *BaseDirectoryName,
*TriggerDirectoryName,
*RingBufferDirectoryName;
BaseDirectoryName = find_type_by_name(device_name, "device");
if (BaseDirectoryName == NULL) {
printf("Failed to find the %s \n", device_name);
return -1;
}
TriggerDirectoryName = find_type_by_name(trigger_name, "trigger");
if (TriggerDirectoryName == NULL) {
printf("Failed to find the %s\n", trigger_name);
return -1;
}
RingBufferDirectoryName = find_ring_subelement(BaseDirectoryName,
"ring_buffer");
if (RingBufferDirectoryName == NULL) {
printf("Failed to find ring buffer\n");
return -1;
}
if (write_sysfs_string_and_verify("trigger/current_trigger",
BaseDirectoryName,
(char *)trigger_name) < 0) {
printf("Failed to write current_trigger file \n");
return -1;
}
/* Setup ring buffer parameters */
if (write_sysfs_int("length", RingBufferDirectoryName,
RingLength) < 0) {
printf("Failed to open the ring buffer length file \n");
return -1;
}
/* Enable the ring buffer */
if (write_sysfs_int("ring_enable", RingBufferDirectoryName, 1) < 0) {
printf("Failed to open the ring buffer control file \n");
return -1;
};
data = malloc(size_from_scanmode(NumVals, scan_ts)*RingLength);
if (!data) {
printf("Could not allocate space for usespace data store\n");
return -1;
}
/* Attempt to open non blocking the access dev */
fp = open(ring_access, O_RDONLY | O_NONBLOCK);
if (fp == -1) { /*If it isn't there make the node */
printf("Failed to open %s\n", ring_access);
return -1;
}
/* Attempt to open the event access dev (blocking this time) */
fp_ev = fopen(ring_event, "rb");
if (fp_ev == NULL) {
printf("Failed to open %s\n", ring_event);
return -1;
}
/* Wait for events 10 times */
for (j = 0; j < 10; j++) {
read_size = fread(&dat, 1, sizeof(struct iio_event_data),
fp_ev);
switch (dat.id) {
case IIO_EVENT_CODE_RING_100_FULL:
toread = RingLength;
break;
case IIO_EVENT_CODE_RING_75_FULL:
toread = RingLength*3/4;
break;
case IIO_EVENT_CODE_RING_50_FULL:
toread = RingLength/2;
break;
default:
printf("Unexpecteded event code\n");
continue;
}
read_size = read(fp,
data,
toread*size_from_scanmode(NumVals, scan_ts));
if (read_size == -EAGAIN) {
printf("nothing available \n");
continue;
}
for (i = 0;
i < read_size/size_from_scanmode(NumVals, scan_ts);
i++) {
for (k = 0; k < NumVals; k++) {
__s16 val = *(__s16 *)(&data[i*size_from_scanmode(NumVals, scan_ts)
+ (k)*2]);
printf("%05d ", val);
}
printf(" %lld\n",
*(__s64 *)(&data[(i+1)*size_from_scanmode(NumVals, scan_ts)
- sizeof(__s64)]));
}
}
/* Stop the ring buffer */
if (write_sysfs_int("ring_enable", RingBufferDirectoryName, 0) < 0) {
printf("Failed to open the ring buffer control file \n");
return -1;
};
/* Disconnect from the trigger - writing something that doesn't exist.*/
write_sysfs_string_and_verify("trigger/current_trigger",
BaseDirectoryName, "NULL");
free(BaseDirectoryName);
free(TriggerDirectoryName);
free(RingBufferDirectoryName);
free(data);
return 0;
}
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