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