hardware/uni-t-ut32x/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "protocol.h"
  21
  22 #include <string.h>
  23 #include <math.h>
  24
  25 extern struct sr_dev_driver uni_t_ut32x_driver_info;
  26 static struct sr_dev_driver *di = &uni_t_ut32x_driver_info;
  27
  28 static float parse_temperature(unsigned char *buf)
  29 {
  30         float temp;
  31         int i;
  32         gboolean negative;
  33
  34         negative = FALSE;
  35         temp = 0.0;
  36         for (i = 0; i < 4; i++) {
  37                 if (buf[i] == 0x3a)
  38                         continue;
  39                 if (buf[i] == 0x3b) {
  40                         if (negative) {
  41                                 sr_dbg("Double negative sign!");
  42                                 return NAN;
  43                         } else {
  44                                 negative = TRUE;
  45                                 continue;
  46                         }
  47                 }
  48                 if (buf[i] < 0x30 || buf[i] > 0x39) {
  49                         sr_dbg("Invalid digit '%.2x'!", buf[i]);
  50                         return NAN;
  51                 }
  52                 temp *= 10;
  53                 temp += (buf[i] - 0x30);
  54         }
  55         temp /= 10;
  56         if (negative)
  57                 temp = -temp;
  58
  59         return temp;
  60 }
  61
  62 static void process_packet(struct sr_dev_inst *sdi)
  63 {
  64         struct dev_context *devc;
  65         struct sr_datafeed_packet packet;
  66         struct sr_datafeed_analog analog;
  67         GString *spew;
  68         float temp;
  69         int i;
  70         gboolean is_valid;
  71
  72         devc = sdi->priv;
  73         sr_dbg("Received full 19-byte packet.");
  74         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
  75                 spew = g_string_sized_new(60);
  76                 for (i = 0; i < devc->packet_len; i++)
  77                         g_string_append_printf(spew, "%.2x ", devc->packet[i]);
  78                 sr_spew("%s", spew->str);
  79                 g_string_free(spew, TRUE);
  80         }
  81
  82         is_valid = TRUE;
  83         if (devc->packet[1] == 0x3b && devc->packet[2] == 0x3b
  84                         && devc->packet[3] == 0x3b && devc->packet[4] == 0x3b)
  85                 /* No measurement: missing channel, empty storage location, ... */
  86                 is_valid = FALSE;
  87
  88         temp = parse_temperature(devc->packet + 1);
  89         if (isnan(temp))
  90                 is_valid = FALSE;
  91
  92         if (is_valid) {
  93                 memset(&analog, 0, sizeof(struct sr_datafeed_analog));
  94                 analog.mq = SR_MQ_TEMPERATURE;
  95                 analog.mqflags = 0;
  96                 switch (devc->packet[5] - 0x30) {
  97                 case 1:
  98                         analog.unit = SR_UNIT_CELSIUS;
  99                         break;
 100                 case 2:
 101                         analog.unit = SR_UNIT_FAHRENHEIT;
 102                         break;
 103                 case 3:
 104                         analog.unit = SR_UNIT_KELVIN;
 105                         break;
 106                 default:
 107                         /* We can still pass on the measurement, whatever it is. */
 108                         sr_dbg("Unknown unit 0x%.2x.", devc->packet[5]);
 109                 }
 110                 switch (devc->packet[13] - 0x30) {
 111                 case 0:
 112                         /* Channel T1. */
 113                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
 114                         break;
 115                 case 1:
 116                         /* Channel T2. */
 117                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 1));
 118                         break;
 119                 case 2:
 120                 case 3:
 121                         /* Channel T1-T2. */
 122                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 2));
 123                         analog.mqflags |= SR_MQFLAG_RELATIVE;
 124                         break;
 125                 default:
 126                         sr_err("Unknown channel 0x%.2x.", devc->packet[13]);
 127                         is_valid = FALSE;
 128                 }
 129                 if (is_valid) {
 130                         analog.num_samples = 1;
 131                         analog.data = &temp;
 132                         packet.type = SR_DF_ANALOG;
 133                         packet.payload = &analog;
 134                         sr_session_send(devc->cb_data, &packet);
 135                         g_slist_free(analog.channels);
 136                 }
 137         }
 138
 139         /* We count packets even if the temperature was invalid. This way
 140          * a sample limit on "Memory" data source still works: unused
 141          * memory slots come through as "----" measurements. */
 142         devc->num_samples++;
 143         if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
 144                 sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
 145                                 devc->cb_data);
 146         }
 147
 148 }
 149
 150 SR_PRIV void uni_t_ut32x_receive_transfer(struct libusb_transfer *transfer)
 151 {
 152         struct dev_context *devc;
 153         struct sr_dev_inst *sdi;
 154         int hid_payload_len, ret;
 155
 156         sdi = transfer->user_data;
 157         devc = sdi->priv;
 158         if (transfer->actual_length == 8) {
 159                 /* CH9325 encodes length in low nibble of first byte, with
 160                  * bytes 1-7 being the (padded) payload. */
 161                 hid_payload_len = transfer->buffer[0] & 0x0f;
 162                 memcpy(devc->packet + devc->packet_len, transfer->buffer + 1,
 163                                 hid_payload_len);
 164                 devc->packet_len += hid_payload_len;
 165                 if (devc->packet_len >= 2
 166                                 && devc->packet[devc->packet_len - 2] == 0x0d
 167                                 && devc->packet[devc->packet_len - 1] == 0x0a) {
 168                         /* Got end of packet, but do we have a complete packet? */
 169                         if (devc->packet_len == 19)
 170                                 process_packet(sdi);
 171                         /* Either way, done with it. */
 172                         devc->packet_len = 0;
 173                 } else if (devc->packet_len > 19) {
 174                         /* Guard against garbage from the device overrunning
 175                          * our packet buffer. */
 176                         sr_dbg("Buffer overrun!");
 177                         devc->packet_len = 0;
 178                 }
 179         }
 180
 181         /* Get the next transfer (unless we're shutting down). */
 182         if (sdi->status != SR_ST_STOPPING) {
 183                 if ((ret = libusb_submit_transfer(devc->xfer)) != 0) {
 184                         sr_dbg("Failed to resubmit transfer: %s", libusb_error_name(ret));
 185                         sdi->status = SR_ST_STOPPING;
 186                         libusb_free_transfer(devc->xfer);
 187                 }
 188         } else
 189                 libusb_free_transfer(devc->xfer);
 190
 191 }
 192
 193 SR_PRIV int uni_t_ut32x_handle_events(int fd, int revents, void *cb_data)
 194 {
 195         struct drv_context *drvc;
 196         struct dev_context *devc;
 197         struct sr_dev_inst *sdi;
 198         struct sr_datafeed_packet packet;
 199         struct sr_usb_dev_inst *usb;
 200         struct timeval tv;
 201         int len, ret;
 202         unsigned char cmd[2];
 203
 204         (void)fd;
 205         (void)revents;
 206
 207         drvc = di->priv;
 208
 209         if (!(sdi = cb_data))
 210                 return TRUE;
 211
 212         if (!(devc = sdi->priv))
 213                 return TRUE;
 214
 215         memset(&tv, 0, sizeof(struct timeval));
 216         libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
 217                         NULL);
 218
 219         if (sdi->status == SR_ST_STOPPING) {
 220                 usb_source_remove(sdi->session, drvc->sr_ctx);
 221                 packet.type = SR_DF_END;
 222                 sr_session_send(cb_data, &packet);
 223
 224                 /* Tell the device to stop sending USB packets. */
 225                 usb = sdi->conn;
 226                 cmd[0] = 0x01;
 227                 cmd[1] = CMD_STOP;
 228                 ret = libusb_bulk_transfer(usb->devhdl, EP_OUT, cmd, 2, &len, 5);
 229                 if (ret != 0 || len != 2) {
 230                         /* Warning only, doesn't matter. */
 231                         sr_dbg("Failed to send stop command: %s", libusb_error_name(ret));
 232                 }
 233
 234                 sdi->status = SR_ST_ACTIVE;
 235                 return TRUE;
 236         }
 237
 238         return TRUE;
 239 }
 240