libsigrok/hardware/uni-t-ut32x/protocol.c

241 lines
6.2 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "protocol.h"
#include <string.h>
#include <math.h>
extern struct sr_dev_driver uni_t_ut32x_driver_info;
static struct sr_dev_driver *di = &uni_t_ut32x_driver_info;
static float parse_temperature(unsigned char *buf)
{
float temp;
int i;
gboolean negative;
negative = FALSE;
temp = 0.0;
for (i = 0; i < 4; i++) {
if (buf[i] == 0x3a)
continue;
if (buf[i] == 0x3b) {
if (negative) {
sr_dbg("Double negative sign!");
return NAN;
} else {
negative = TRUE;
continue;
}
}
if (buf[i] < 0x30 || buf[i] > 0x39) {
sr_dbg("Invalid digit '%.2x'!", buf[i]);
return NAN;
}
temp *= 10;
temp += (buf[i] - 0x30);
}
temp /= 10;
if (negative)
temp = -temp;
return temp;
}
static void process_packet(struct sr_dev_inst *sdi)
{
struct dev_context *devc;
struct sr_datafeed_packet packet;
struct sr_datafeed_analog analog;
GString *spew;
float temp;
int i;
gboolean is_valid;
devc = sdi->priv;
sr_dbg("Received full 19-byte packet.");
if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
spew = g_string_sized_new(60);
for (i = 0; i < devc->packet_len; i++)
g_string_append_printf(spew, "%.2x ", devc->packet[i]);
sr_spew("%s", spew->str);
g_string_free(spew, TRUE);
}
is_valid = TRUE;
if (devc->packet[1] == 0x3b && devc->packet[2] == 0x3b
&& devc->packet[3] == 0x3b && devc->packet[4] == 0x3b)
/* No measurement: missing channel, empty storage location, ... */
is_valid = FALSE;
temp = parse_temperature(devc->packet + 1);
if (isnan(temp))
is_valid = FALSE;
if (is_valid) {
memset(&analog, 0, sizeof(struct sr_datafeed_analog));
analog.mq = SR_MQ_TEMPERATURE;
analog.mqflags = 0;
switch (devc->packet[5] - 0x30) {
case 1:
analog.unit = SR_UNIT_CELSIUS;
break;
case 2:
analog.unit = SR_UNIT_FAHRENHEIT;
break;
case 3:
analog.unit = SR_UNIT_KELVIN;
break;
default:
/* We can still pass on the measurement, whatever it is. */
sr_dbg("Unknown unit 0x%.2x.", devc->packet[5]);
}
switch (devc->packet[13] - 0x30) {
case 0:
/* Channel T1. */
analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
break;
case 1:
/* Channel T2. */
analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 1));
break;
case 2:
case 3:
/* Channel T1-T2. */
analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 2));
analog.mqflags |= SR_MQFLAG_RELATIVE;
break;
default:
sr_err("Unknown channel 0x%.2x.", devc->packet[13]);
is_valid = FALSE;
}
if (is_valid) {
analog.num_samples = 1;
analog.data = &temp;
packet.type = SR_DF_ANALOG;
packet.payload = &analog;
sr_session_send(devc->cb_data, &packet);
g_slist_free(analog.channels);
}
}
/* We count packets even if the temperature was invalid. This way
* a sample limit on "Memory" data source still works: unused
* memory slots come through as "----" measurements. */
devc->num_samples++;
if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
devc->cb_data);
}
}
SR_PRIV void uni_t_ut32x_receive_transfer(struct libusb_transfer *transfer)
{
struct dev_context *devc;
struct sr_dev_inst *sdi;
int hid_payload_len, ret;
sdi = transfer->user_data;
devc = sdi->priv;
if (transfer->actual_length == 8) {
/* CH9325 encodes length in low nibble of first byte, with
* bytes 1-7 being the (padded) payload. */
hid_payload_len = transfer->buffer[0] & 0x0f;
memcpy(devc->packet + devc->packet_len, transfer->buffer + 1,
hid_payload_len);
devc->packet_len += hid_payload_len;
if (devc->packet_len >= 2
&& devc->packet[devc->packet_len - 2] == 0x0d
&& devc->packet[devc->packet_len - 1] == 0x0a) {
/* Got end of packet, but do we have a complete packet? */
if (devc->packet_len == 19)
process_packet(sdi);
/* Either way, done with it. */
devc->packet_len = 0;
} else if (devc->packet_len > 19) {
/* Guard against garbage from the device overrunning
* our packet buffer. */
sr_dbg("Buffer overrun!");
devc->packet_len = 0;
}
}
/* Get the next transfer (unless we're shutting down). */
if (sdi->status != SR_ST_STOPPING) {
if ((ret = libusb_submit_transfer(devc->xfer)) != 0) {
sr_dbg("Failed to resubmit transfer: %s", libusb_error_name(ret));
sdi->status = SR_ST_STOPPING;
libusb_free_transfer(devc->xfer);
}
} else
libusb_free_transfer(devc->xfer);
}
SR_PRIV int uni_t_ut32x_handle_events(int fd, int revents, void *cb_data)
{
struct drv_context *drvc;
struct dev_context *devc;
struct sr_dev_inst *sdi;
struct sr_datafeed_packet packet;
struct sr_usb_dev_inst *usb;
struct timeval tv;
int len, ret;
unsigned char cmd[2];
(void)fd;
(void)revents;
drvc = di->priv;
if (!(sdi = cb_data))
return TRUE;
if (!(devc = sdi->priv))
return TRUE;
memset(&tv, 0, sizeof(struct timeval));
libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
NULL);
if (sdi->status == SR_ST_STOPPING) {
usb_source_remove(drvc->sr_ctx);
packet.type = SR_DF_END;
sr_session_send(cb_data, &packet);
/* Tell the device to stop sending USB packets. */
usb = sdi->conn;
cmd[0] = 0x01;
cmd[1] = CMD_STOP;
ret = libusb_bulk_transfer(usb->devhdl, EP_OUT, cmd, 2, &len, 5);
if (ret != 0 || len != 2) {
/* Warning only, doesn't matter. */
sr_dbg("Failed to send stop command: %s", libusb_error_name(ret));
}
sdi->status = SR_ST_ACTIVE;
return TRUE;
}
return TRUE;
}