src/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 <string.h>
  21 #include <math.h>
  22 #include "protocol.h"
  23
  24 extern struct sr_dev_driver uni_t_ut32x_driver_info;
  25
  26 static float parse_temperature(unsigned char *buf)
  27 {
  28         float temp;
  29         int i;
  30         gboolean negative;
  31
  32         negative = FALSE;
  33         temp = 0.0;
  34         for (i = 0; i < 4; i++) {
  35                 if (buf[i] == 0x3a)
  36                         continue;
  37                 if (buf[i] == 0x3b) {
  38                         if (negative) {
  39                                 sr_dbg("Double negative sign!");
  40                                 return NAN;
  41                         } else {
  42                                 negative = TRUE;
  43                                 continue;
  44                         }
  45                 }
  46                 if (buf[i] < 0x30 || buf[i] > 0x39) {
  47                         sr_dbg("Invalid digit '%.2x'!", buf[i]);
  48                         return NAN;
  49                 }
  50                 temp *= 10;
  51                 temp += (buf[i] - 0x30);
  52         }
  53         temp /= 10;
  54         if (negative)
  55                 temp = -temp;
  56
  57         return temp;
  58 }
  59
  60 static void process_packet(struct sr_dev_inst *sdi)
  61 {
  62         struct dev_context *devc;
  63         struct sr_datafeed_packet packet;
  64         struct sr_datafeed_analog analog;
  65         GString *spew;
  66         float temp;
  67         int i;
  68         gboolean is_valid;
  69
  70         devc = sdi->priv;
  71         sr_dbg("Received full 19-byte packet.");
  72         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
  73                 spew = g_string_sized_new(60);
  74                 for (i = 0; i < devc->packet_len; i++)
  75                         g_string_append_printf(spew, "%.2x ", devc->packet[i]);
  76                 sr_spew("%s", spew->str);
  77                 g_string_free(spew, TRUE);
  78         }
  79
  80         is_valid = TRUE;
  81         if (devc->packet[1] == 0x3b && devc->packet[2] == 0x3b
  82                         && devc->packet[3] == 0x3b && devc->packet[4] == 0x3b)
  83                 /* No measurement: missing channel, empty storage location, ... */
  84                 is_valid = FALSE;
  85
  86         temp = parse_temperature(devc->packet + 1);
  87         if (isnan(temp))
  88                 is_valid = FALSE;
  89
  90         if (is_valid) {
  91                 memset(&analog, 0, sizeof(struct sr_datafeed_analog));
  92                 analog.mq = SR_MQ_TEMPERATURE;
  93                 analog.mqflags = 0;
  94                 switch (devc->packet[5] - 0x30) {
  95                 case 1:
  96                         analog.unit = SR_UNIT_CELSIUS;
  97                         break;
  98                 case 2:
  99                         analog.unit = SR_UNIT_FAHRENHEIT;
 100                         break;
 101                 case 3:
 102                         analog.unit = SR_UNIT_KELVIN;
 103                         break;
 104                 default:
 105                         /* We can still pass on the measurement, whatever it is. */
 106                         sr_dbg("Unknown unit 0x%.2x.", devc->packet[5]);
 107                 }
 108                 switch (devc->packet[13] - 0x30) {
 109                 case 0:
 110                         /* Channel T1. */
 111                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
 112                         break;
 113                 case 1:
 114                         /* Channel T2. */
 115                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 1));
 116                         break;
 117                 case 2:
 118                 case 3:
 119                         /* Channel T1-T2. */
 120                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 2));
 121                         analog.mqflags |= SR_MQFLAG_RELATIVE;
 122                         break;
 123                 default:
 124                         sr_err("Unknown channel 0x%.2x.", devc->packet[13]);
 125                         is_valid = FALSE;
 126                 }
 127                 if (is_valid) {
 128                         analog.num_samples = 1;
 129                         analog.data = &temp;
 130                         packet.type = SR_DF_ANALOG;
 131                         packet.payload = &analog;
 132                         sr_session_send(devc->cb_data, &packet);
 133                         g_slist_free(analog.channels);
 134                 }
 135         }
 136
 137         /* We count packets even if the temperature was invalid. This way
 138          * a sample limit on "Memory" data source still works: unused
 139          * memory slots come through as "----" measurements. */
 140         devc->num_samples++;
 141         if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
 142                 sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
 143                                 devc->cb_data);
 144         }
 145
 146 }
 147
 148 SR_PRIV void uni_t_ut32x_receive_transfer(struct libusb_transfer *transfer)
 149 {
 150         struct dev_context *devc;
 151         struct sr_dev_inst *sdi;
 152         int hid_payload_len, ret;
 153
 154         sdi = transfer->user_data;
 155         devc = sdi->priv;
 156         if (transfer->actual_length == 8) {
 157                 /* CH9325 encodes length in low nibble of first byte, with
 158                  * bytes 1-7 being the (padded) payload. */
 159                 hid_payload_len = transfer->buffer[0] & 0x0f;
 160                 memcpy(devc->packet + devc->packet_len, transfer->buffer + 1,
 161                                 hid_payload_len);
 162                 devc->packet_len += hid_payload_len;
 163                 if (devc->packet_len >= 2
 164                                 && devc->packet[devc->packet_len - 2] == 0x0d
 165                                 && devc->packet[devc->packet_len - 1] == 0x0a) {
 166                         /* Got end of packet, but do we have a complete packet? */
 167                         if (devc->packet_len == 19)
 168                                 process_packet(sdi);
 169                         /* Either way, done with it. */
 170                         devc->packet_len = 0;
 171                 } else if (devc->packet_len > 19) {
 172                         /* Guard against garbage from the device overrunning
 173                          * our packet buffer. */
 174                         sr_dbg("Buffer overrun!");
 175                         devc->packet_len = 0;
 176                 }
 177         }
 178
 179         /* Get the next transfer (unless we're shutting down). */
 180         if (sdi->status != SR_ST_STOPPING) {
 181                 if ((ret = libusb_submit_transfer(devc->xfer)) != 0) {
 182                         sr_dbg("Failed to resubmit transfer: %s", libusb_error_name(ret));
 183                         sdi->status = SR_ST_STOPPING;
 184                         libusb_free_transfer(devc->xfer);
 185                 }
 186         } else
 187                 libusb_free_transfer(devc->xfer);
 188
 189 }
 190
 191 SR_PRIV int uni_t_ut32x_handle_events(int fd, int revents, void *cb_data)
 192 {
 193         struct drv_context *drvc;
 194         struct dev_context *devc;
 195         struct sr_dev_driver *di;
 196         struct sr_dev_inst *sdi;
 197         struct sr_datafeed_packet packet;
 198         struct sr_usb_dev_inst *usb;
 199         struct timeval tv;
 200         int len, ret;
 201         unsigned char cmd[2];
 202
 203         (void)fd;
 204         (void)revents;
 205
 206         if (!(sdi = cb_data))
 207                 return TRUE;
 208
 209         di = sdi->driver;
 210         drvc = di->priv;
 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 }