hardware/testo/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2014 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 <string.h>
  21 #include "protocol.h"
  22
  23 SR_PRIV int testo_set_serial_params(struct sr_usb_dev_inst *usb)
  24 {
  25         int ret;
  26
  27     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_BAUDRATE,
  28                         FTDI_BAUDRATE_115200, FTDI_INDEX, NULL, 0, 10)) < 0) {
  29                         sr_err("Failed to set baudrate: %s", libusb_error_name(ret));
  30                         return SR_ERR;
  31         }
  32
  33     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_PARAMS,
  34                         FTDI_PARAMS_8N1, FTDI_INDEX, NULL, 0, 10)) < 0) {
  35                         sr_err("Failed to set comm parameters: %s", libusb_error_name(ret));
  36                         return SR_ERR;
  37         }
  38
  39     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_FLOWCTRL,
  40                         FTDI_FLOW_NONE, FTDI_INDEX, NULL, 0, 10)) < 0) {
  41                         sr_err("Failed to set flow control: %s", libusb_error_name(ret));
  42                         return SR_ERR;
  43         }
  44
  45     if ((ret = libusb_control_transfer(usb->devhdl, 0x40, FTDI_SET_MODEMCTRL,
  46                         FTDI_MODEM_ALLHIGH, FTDI_INDEX, NULL, 0, 10)) < 0) {
  47                         sr_err("Failed to set modem control: %s", libusb_error_name(ret));
  48                         return SR_ERR;
  49         }
  50
  51         return SR_OK;
  52 }
  53
  54
  55 /* Due to the modular nature of the Testo hardware, you can't assume
  56  * which measurements the device will supply. Fetch a single result
  57  * set synchronously to see which measurements it has. */
  58 SR_PRIV int testo_probe_channels(struct sr_dev_inst *sdi)
  59 {
  60         struct dev_context *devc;
  61         struct sr_usb_dev_inst *usb;
  62         struct sr_channel *ch;
  63         int unit, packet_len, len, i;
  64         unsigned char packet[MAX_REPLY_SIZE], buf[MAX_REPLY_SIZE];
  65         char *probe_name;
  66
  67         devc = sdi->priv;
  68         usb = sdi->conn;
  69
  70         sr_dbg("Probing for channels.");
  71         if (sdi->driver->dev_open(sdi) != SR_OK)
  72                 return SR_ERR;
  73         if (testo_set_serial_params(usb) != SR_OK)
  74                 return SR_ERR;
  75
  76         /* Flush anything buffered from a previous run. */
  77         do {
  78                 libusb_bulk_transfer(usb->devhdl, EP_IN, buf, MAX_REPLY_SIZE, &len, 10);
  79         } while (len > 2);
  80
  81         if (libusb_bulk_transfer(usb->devhdl, EP_OUT, devc->model->request,
  82                         devc->model->request_size, &devc->reply_size, 10) < 0)
  83                 return SR_ERR;
  84
  85         packet_len = 0;
  86         while(TRUE) {
  87                 if (libusb_bulk_transfer(usb->devhdl, EP_IN, buf, MAX_REPLY_SIZE,
  88                                 &len, 250) < 0)
  89                         return SR_ERR;
  90                 if (len == 2)
  91                         /* FTDI cruft */
  92                         continue;
  93                 if (packet_len + len - 2 > MAX_REPLY_SIZE)
  94                         return SR_ERR;
  95
  96                 memcpy(packet + packet_len, buf + 2, len - 2);
  97                 packet_len += len - 2;
  98                 if (packet_len < 5)
  99                         /* Not even enough to check prefix yet. */
 100                         continue;
 101
 102                 if (!testo_check_packet_prefix(packet, packet_len)) {
 103                         /* Tail end of some previous data, drop it. */
 104                         packet_len = 0;
 105                         continue;
 106                 }
 107
 108                 if (packet_len >= 7 + packet[6] * 7 + 2)
 109                         /* Got a complete packet. */
 110                         break;
 111         }
 112         sdi->driver->dev_close(sdi);
 113
 114         if (packet[6] > MAX_CHANNELS) {
 115                 sr_err("Device says it has %d channels!", packet[6]);
 116                 return SR_ERR;
 117         }
 118
 119         for (i = 0; i < packet[6]; i++) {
 120                 unit = packet[7 + i * 7 + 4];
 121                 devc->channel_units[i] = unit;
 122                 switch (unit) {
 123                 case 1:
 124                         probe_name = "Temperature";
 125                         break;
 126                 case 3:
 127                         probe_name = "Humidity";
 128                         break;
 129                 case 5:
 130                         probe_name = "Windspeed";
 131                         break;
 132                 case 24:
 133                         probe_name = "Pressure";
 134                         break;
 135                 default:
 136                         sr_dbg("Unsupported measurement unit %d", unit);
 137                         return SR_ERR;
 138                 }
 139                 ch = sr_channel_new(i, SR_CHANNEL_ANALOG, TRUE, probe_name);
 140                 sdi->channels = g_slist_append(sdi->channels, ch);
 141         }
 142         devc->num_channels = packet[6];
 143         sr_dbg("Found %d channel%s.", devc->num_channels,
 144                         devc->num_channels > 1 ? "s" : "");
 145
 146         return SR_OK;
 147 }
 148
 149 SR_PRIV int testo_request_packet(const struct sr_dev_inst *sdi)
 150 {
 151         struct dev_context *devc;
 152         struct sr_usb_dev_inst *usb;
 153         int ret;
 154
 155         devc = sdi->priv;
 156         usb = sdi->conn;
 157
 158         libusb_fill_bulk_transfer(devc->out_transfer, usb->devhdl, EP_OUT,
 159                         devc->model->request, devc->model->request_size,
 160                         receive_transfer, (void *)sdi, 100);
 161         if ((ret = libusb_submit_transfer(devc->out_transfer) != 0)) {
 162                 sr_err("Failed to request packet: %s.", libusb_error_name(ret));
 163                 sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
 164                                 devc->cb_data);
 165                 return SR_ERR;
 166         }
 167         sr_dbg("Requested new packet.");
 168
 169         return SR_OK;
 170 }
 171
 172 /* Check if the packet is well-formed. This matches packets for the
 173  * Testo 175/177/400/650/950/435/635/735/445/645/945/946/545. */
 174 SR_PRIV gboolean testo_check_packet_prefix(unsigned char *buf, int len)
 175 {
 176         int i;
 177         unsigned char check[] = { 0x21, 0, 0, 0, 1 };
 178
 179         if (len < 5)
 180                 return FALSE;
 181
 182         for (i = 0; i < 5; i++) {
 183                 if (buf[i] != check[i]) {
 184                         sr_dbg("Packet has invalid prefix.");
 185                         return FALSE;
 186                 }
 187         }
 188
 189         return TRUE;
 190 }
 191
 192 SR_PRIV uint16_t crc16_mcrf4xx(uint16_t crc, uint8_t *data, size_t len)
 193 {
 194         int i;
 195
 196         if (!data || !len)
 197                 return crc;
 198
 199         while (len--) {
 200                 crc ^= *data++;
 201                 for (i = 0; i < 8; i++) {
 202                         if (crc & 1)
 203                                 crc = (crc >> 1) ^ 0x8408;
 204                         else
 205                                 crc = (crc >> 1);
 206                 }
 207         }
 208
 209         return crc;
 210 }
 211
 212 static float binary32_le_to_float(unsigned char *buf)
 213 {
 214         GFloatIEEE754 f;
 215
 216         f.v_float = 0;
 217         f.mpn.sign = (buf[3] & 0x80) ? 1 : 0;
 218         f.mpn.biased_exponent = (buf[3] << 1) | (buf[2] >> 7);
 219         f.mpn.mantissa = buf[0] | (buf[1] << 8) | ((buf[2] & 0x7f) << 16);
 220
 221         return f.v_float;
 222 }
 223
 224 SR_PRIV void testo_receive_packet(const struct sr_dev_inst *sdi)
 225 {
 226         struct dev_context *devc;
 227         struct sr_datafeed_packet packet;
 228         struct sr_datafeed_analog analog;
 229         struct sr_channel *ch;
 230         GString *dbg;
 231         float value;
 232         int i;
 233         unsigned char *buf;
 234
 235         devc = sdi->priv;
 236         sr_dbg("Got %d-byte packet.", devc->reply_size);
 237
 238         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
 239                 dbg = g_string_sized_new(128);
 240                 g_string_printf(dbg, "Packet:");
 241                 for (i = 0; i < devc->reply_size; i++)
 242                         g_string_append_printf(dbg, " %.2x", devc->reply[i]);
 243                 sr_spew("%s", dbg->str);
 244                 g_string_free(dbg, TRUE);
 245         }
 246
 247         packet.type = SR_DF_ANALOG;
 248         packet.payload = &analog;
 249         analog.num_samples = 1;
 250         analog.mqflags = 0;
 251         analog.data = &value;
 252         /* Decode 7-byte values */
 253         for (i = 0; i < devc->reply[6]; i++) {
 254                 buf = devc->reply + 7 + i * 7;
 255                 value = binary32_le_to_float(buf);
 256                 switch (buf[4]) {
 257                 case 1:
 258                         analog.mq = SR_MQ_TEMPERATURE;
 259                         analog.unit = SR_UNIT_CELSIUS;
 260                         break;
 261                 case 3:
 262                         analog.mq = SR_MQ_RELATIVE_HUMIDITY;
 263                         analog.unit = SR_UNIT_HUMIDITY_293K;
 264                         break;
 265                 case 5:
 266                         analog.mq = SR_MQ_WIND_SPEED;
 267                         analog.unit = SR_UNIT_METER_SECOND;
 268                         break;
 269                 case 24:
 270                         analog.mq = SR_MQ_PRESSURE;
 271                         analog.unit = SR_UNIT_HECTOPASCAL;
 272                         break;
 273                 default:
 274                         sr_dbg("Unsupported measurement unit %d.", buf[4]);
 275                         return;
 276                 }
 277
 278                 /* Match this measurement with its channel. */
 279                 for (i = 0; i < devc->num_channels; i++) {
 280                         if (devc->channel_units[i] == buf[4])
 281                                 break;
 282                 }
 283                 if (i == devc->num_channels) {
 284                         /* Shouldn't happen. */
 285                         sr_err("Some channel hotswapped in!");
 286                         return;
 287                 }
 288                 ch = g_slist_nth_data(sdi->channels, i);
 289                 analog.channels = g_slist_append(NULL, ch);
 290                 sr_session_send(sdi, &packet);
 291                 g_slist_free(analog.channels);
 292         }
 293 }
 294