libsigrok/src/hardware/kern-scale/protocol.c

132 lines
3.4 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2015 Uwe Hermann <uwe@hermann-uwe.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <glib.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "protocol.h"
static void handle_packet(const uint8_t *buf, struct sr_dev_inst *sdi,
void *info)
{
struct scale_info *scale;
float floatval;
struct sr_datafeed_packet packet;
struct sr_datafeed_analog analog;
struct sr_analog_encoding encoding;
struct sr_analog_meaning meaning;
struct sr_analog_spec spec;
struct dev_context *devc;
scale = (struct scale_info *)sdi->driver;
devc = sdi->priv;
sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
analog.meaning->channels = sdi->channels;
analog.num_samples = 1;
analog.meaning->mq = 0;
scale->packet_parse(buf, &floatval, &analog, info);
analog.data = &floatval;
if (analog.meaning->mq != 0) {
/* Got a measurement. */
packet.type = SR_DF_ANALOG;
packet.payload = &analog;
sr_session_send(sdi, &packet);
sr_sw_limits_update_samples_read(&devc->limits, 1);
}
}
static void handle_new_data(struct sr_dev_inst *sdi, void *info)
{
struct scale_info *scale;
struct dev_context *devc;
int len, i, offset = 0;
struct sr_serial_dev_inst *serial;
scale = (struct scale_info *)sdi->driver;
devc = sdi->priv;
serial = sdi->conn;
/* Try to get as much data as the buffer can hold. */
len = SCALE_BUFSIZE - devc->buflen;
len = serial_read_nonblocking(serial, devc->buf + devc->buflen, len);
if (len == 0)
return; /* No new bytes, nothing to do. */
if (len < 0) {
sr_err("Serial port read error: %d.", len);
return;
}
devc->buflen += len;
/* Now look for packets in that data. */
while ((devc->buflen - offset) >= scale->packet_size) {
if (scale->packet_valid(devc->buf + offset)) {
handle_packet(devc->buf + offset, sdi, info);
offset += scale->packet_size;
} else {
offset++;
}
}
/* If we have any data left, move it to the beginning of our buffer. */
for (i = 0; i < devc->buflen - offset; i++)
devc->buf[i] = devc->buf[offset + i];
devc->buflen -= offset;
}
SR_PRIV int kern_scale_receive_data(int fd, int revents, void *cb_data)
{
struct sr_dev_inst *sdi;
struct dev_context *devc;
struct scale_info *scale;
void *info;
(void)fd;
if (!(sdi = cb_data))
return TRUE;
if (!(devc = sdi->priv))
return TRUE;
scale = (struct scale_info *)sdi->driver;
if (revents == G_IO_IN) {
/* Serial data arrived. */
info = g_malloc(scale->info_size);
handle_new_data(sdi, info);
g_free(info);
}
if (sr_sw_limits_check(&devc->limits))
sdi->driver->dev_acquisition_stop(sdi);
return TRUE;
}