/* Industrialio buffer test code.
*
* 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.
*
* This program is primarily intended as an example application.
* Reads the current buffer setup from sysfs and starts a short capture
* from the specified device, pretty printing the result after appropriate
* conversion.
*
* Command line parameters
* generic_buffer -n <device_name> -t <trigger_name>
* If trigger name is not specified the program assumes you want a dataready
* trigger associated with the device and goes looking for it.
*
*/
#include <unistd.h>
#include <stdlib.h>
#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/dir.h>
#include <linux/types.h>
#include <string.h>
#include <poll.h>
#include <endian.h>
#include <getopt.h>
#include <inttypes.h>
#include "iio_utils.h"
/**
* size_from_channelarray() - calculate the storage size of a scan
* @channels: the channel info array
* @num_channels: number of channels
*
* Has the side effect of filling the channels[i].location values used
* in processing the buffer output.
**/
int size_from_channelarray(struct iio_channel_info *channels, int num_channels)
{
int bytes = 0;
int i = 0;
while (i < num_channels) {
if (bytes % channels[i].bytes == 0)
channels[i].location = bytes;
else
channels[i].location = bytes - bytes%channels[i].bytes
+ channels[i].bytes;
bytes = channels[i].location + channels[i].bytes;
i++;
}
return bytes;
}
void print2byte(int input, struct iio_channel_info *info)
{
/* First swap if incorrect endian */
if (info->be)
input = be16toh((uint16_t)input);
else
input = le16toh((uint16_t)input);
/*
* Shift before conversion to avoid sign extension
* of left aligned data
*/
input >>= info->shift;
if (info->is_signed) {
int16_t val = input;
val &= (1 << info->bits_used) - 1;
val = (int16_t)(val << (16 - info->bits_used)) >>
(16 - info->bits_used);
printf("%05f ", ((float)val + info->offset)*info->scale);
} else {
uint16_t val = input;
val &= (1 << info->bits_used) - 1;
printf("%05f ", ((float)val + info->offset)*info->scale);
}
}
/**
* process_scan() - print out the values in SI units
* @data: pointer to the start of the scan
* @channels: information about the channels. Note
* size_from_channelarray must have been called first to fill the
* location offsets.
* @num_channels: number of channels
**/
void process_scan(char *data,
struct iio_channel_info *channels,
int num_channels)
{
int k;
for (k = 0; k < num_channels; k++)
switch (channels[k].bytes) {
/* only a few cases implemented so far */
case 2:
print2byte(*(uint16_t *)(data + channels[k].location),
&channels[k]);
break;
case 4:
if (!channels[k].is_signed) {
uint32_t val = *(uint32_t *)
(data + channels[k].location);
printf("%05f ", ((float)val +
channels[k].offset)*
channels[k].scale);
}
break;
case 8:
if (channels[k].is_signed) {
int64_t val = *(int64_t *)
(data +
channels[k].location);
if ((val >> channels[k].bits_used) & 1)
val = (val & channels[k].mask) |
~channels[k].mask;
/* special case for timestamp */
if (channels[k].scale == 1.0f &&
channels[k].offset == 0.0f)
printf("%" PRId64 " ", val);
else
printf("%05f ", ((float)val +
channels[k].offset)*
channels[k].scale);
}
break;
default:
break;
}
printf("\n");
}
int main(int argc, char **argv)
{
unsigned long num_loops = 2;
unsigned long timedelay = 1000000;
unsigned long buf_len = 128;
int ret, c, i, j, toread;
int fp;
int num_channels;
char *trigger_name = NULL, *device_name = NULL;
char *dev_dir_name, *buf_dir_name;
int datardytrigger = 1;
char *data;
ssize_t read_size;
int dev_num, trig_num;
char *buffer_access;
int scan_size;
int noevents = 0;
int notrigger = 0;
char *dummy;
struct iio_channel_info *channels;
while ((c = getopt(argc, argv, "l:w:c:et:n:g")) != -1) {
switch (c) {
case 'n':
device_name = optarg;
break;
case 't':
trigger_name = optarg;
datardytrigger = 0;
break;
case 'e':
noevents = 1;
break;
case 'c':
num_loops = strtoul(optarg, &dummy, 10);
break;
case 'w':
timedelay = strtoul(optarg, &dummy, 10);
break;
case 'l':
buf_len = strtoul(optarg, &dummy, 10);
break;
case 'g':
notrigger = 1;
break;
case '?':
return -1;
}
}
if (device_name == NULL)
return -1;
/* Find the device requested */
dev_num = find_type_by_name(device_name, "iio:device");
if (dev_num < 0) {
printf("Failed to find the %s\n", device_name);
ret = -ENODEV;
goto error_ret;
}
printf("iio device number being used is %d\n", dev_num);
asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);
if (!notrigger) {
if (trigger_name == NULL) {
/*
* Build the trigger name. If it is device associated
* its name is <device_name>_dev[n] where n matches
* the device number found above.
*/
ret = asprintf(&trigger_name,
"%s-dev%d", device_name, dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error_ret;
}
}
/* Verify the trigger exists */
trig_num = find_type_by_name(trigger_name, "trigger");
if (trig_num < 0) {
printf("Failed to find the trigger %s\n", trigger_name);
ret = -ENODEV;
goto error_free_triggername;
}
printf("iio trigger number being used is %d\n", trig_num);
} else
printf("trigger-less mode selected\n");
/*
* Parse the files in scan_elements to identify what channels are
* present
*/
ret = build_channel_array(dev_dir_name, &channels, &num_channels);
if (ret) {
printf("Problem reading scan element information\n");
printf("diag %s\n", dev_dir_name);
goto error_free_triggername;
}
/*
* Construct the directory name for the associated buffer.
* As we know that the lis3l02dq has only one buffer this may
* be built rather than found.
*/
ret = asprintf(&buf_dir_name,
"%siio:device%d/buffer", iio_dir, dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error_free_triggername;
}
if (!notrigger) {
printf("%s %s\n", dev_dir_name, trigger_name);
/* Set the device trigger to be the data ready trigger found
* above */
ret = write_sysfs_string_and_verify("trigger/current_trigger",
dev_dir_name,
trigger_name);
if (ret < 0) {
printf("Failed to write current_trigger file\n");
goto error_free_buf_dir_name;
}
}
/* Setup ring buffer parameters */
ret = write_sysfs_int("length", buf_dir_name, buf_len);
if (ret < 0)
goto error_free_buf_dir_name;
/* Enable the buffer */
ret = write_sysfs_int("enable", buf_dir_name, 1);
if (ret < 0)
goto error_free_buf_dir_name;
scan_size = size_from_channelarray(channels, num_channels);
data = malloc(scan_size*buf_len);
if (!data) {
ret = -ENOMEM;
goto error_free_buf_dir_name;
}
ret = asprintf(&buffer_access, "/dev/iio:device%d", dev_num);
if (ret < 0) {
ret = -ENOMEM;
goto error_free_data;
}
/* Attempt to open non blocking the access dev */
fp = open(buffer_access, O_RDONLY | O_NONBLOCK);
if (fp == -1) { /* If it isn't there make the node */
printf("Failed to open %s\n", buffer_access);
ret = -errno;
goto error_free_buffer_access;
}
/* Wait for events 10 times */
for (j = 0; j < num_loops; j++) {
if (!noevents) {
struct pollfd pfd = {
.fd = fp,
.events = POLLIN,
};
poll(&pfd, 1, -1);
toread = buf_len;
} else {
usleep(timedelay);
toread = 64;
}
read_size = read(fp,
data,
toread*scan_size);
if (read_size < 0) {
if (errno == -EAGAIN) {
printf("nothing available\n");
continue;
} else
break;
}
for (i = 0; i < read_size/scan_size; i++)
process_scan(data + scan_size*i,
channels,
num_channels);
}
/* Stop the buffer */
ret = write_sysfs_int("enable", buf_dir_name, 0);
if (ret < 0)
goto error_close_buffer_access;
if (!notrigger)
/* Disconnect the trigger - just write a dummy name. */
write_sysfs_string("trigger/current_trigger",
dev_dir_name, "NULL");
error_close_buffer_access:
close(fp);
error_free_data:
free(data);
error_free_buffer_access:
free(buffer_access);
error_free_buf_dir_name:
free(buf_dir_name);
error_free_triggername:
if (datardytrigger)
free(trigger_name);
error_ret:
return ret;
}