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