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 <config.h>
  21 #include <string.h>
  22 #include <math.h>
  23 #include "protocol.h"
  24
  25 extern struct sr_dev_driver uni_t_ut32x_driver_info;
  26
  27 static float parse_temperature(unsigned char *buf)
  28 {
  29         float temp;
  30         int i;
  31         gboolean negative;
  32
  33         negative = FALSE;
  34         temp = 0.0;
  35         for (i = 0; i < 4; i++) {
  36                 if (buf[i] == 0x3a)
  37                         continue;
  38                 if (buf[i] == 0x3b) {
  39                         if (negative) {
  40                                 sr_dbg("Double negative sign!");
  41                                 return NAN;
  42                         } else {
  43                                 negative = TRUE;
  44                                 continue;
  45                         }
  46                 }
  47                 if (buf[i] < 0x30 || buf[i] > 0x39) {
  48                         sr_dbg("Invalid digit '%.2x'!", buf[i]);
  49                         return NAN;
  50                 }
  51                 temp *= 10;
  52                 temp += (buf[i] - 0x30);
  53         }
  54         temp /= 10;
  55         if (negative)
  56                 temp = -temp;
  57
  58         return temp;
  59 }
  60
  61 static void process_packet(struct sr_dev_inst *sdi)
  62 {
  63         struct dev_context *devc;
  64         struct sr_datafeed_packet packet;
  65         struct sr_datafeed_analog_old analog;
  66         GString *spew;
  67         float temp;
  68         int i;
  69         gboolean is_valid;
  70
  71         devc = sdi->priv;
  72         sr_dbg("Received full 19-byte packet.");
  73         if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
  74                 spew = g_string_sized_new(60);
  75                 for (i = 0; i < devc->packet_len; i++)
  76                         g_string_append_printf(spew, "%.2x ", devc->packet[i]);
  77                 sr_spew("%s", spew->str);
  78                 g_string_free(spew, TRUE);
  79         }
  80
  81         is_valid = TRUE;
  82         if (devc->packet[1] == 0x3b && devc->packet[2] == 0x3b
  83                         && devc->packet[3] == 0x3b && devc->packet[4] == 0x3b)
  84                 /* No measurement: missing channel, empty storage location, ... */
  85                 is_valid = FALSE;
  86
  87         temp = parse_temperature(devc->packet + 1);
  88         if (isnan(temp))
  89                 is_valid = FALSE;
  90
  91         if (is_valid) {
  92                 memset(&analog, 0, sizeof(struct sr_datafeed_analog_old));
  93                 analog.mq = SR_MQ_TEMPERATURE;
  94                 analog.mqflags = 0;
  95                 switch (devc->packet[5] - 0x30) {
  96                 case 1:
  97                         analog.unit = SR_UNIT_CELSIUS;
  98                         break;
  99                 case 2:
 100                         analog.unit = SR_UNIT_FAHRENHEIT;
 101                         break;
 102                 case 3:
 103                         analog.unit = SR_UNIT_KELVIN;
 104                         break;
 105                 default:
 106                         /* We can still pass on the measurement, whatever it is. */
 107                         sr_dbg("Unknown unit 0x%.2x.", devc->packet[5]);
 108                 }
 109                 switch (devc->packet[13] - 0x30) {
 110                 case 0:
 111                         /* Channel T1. */
 112                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 0));
 113                         break;
 114                 case 1:
 115                         /* Channel T2. */
 116                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 1));
 117                         break;
 118                 case 2:
 119                 case 3:
 120                         /* Channel T1-T2. */
 121                         analog.channels = g_slist_append(NULL, g_slist_nth_data(sdi->channels, 2));
 122                         analog.mqflags |= SR_MQFLAG_RELATIVE;
 123                         break;
 124                 default:
 125                         sr_err("Unknown channel 0x%.2x.", devc->packet[13]);
 126                         is_valid = FALSE;
 127                 }
 128                 if (is_valid) {
 129                         analog.num_samples = 1;
 130                         analog.data = &temp;
 131                         packet.type = SR_DF_ANALOG_OLD;
 132                         packet.payload = &analog;
 133                         sr_session_send(sdi, &packet);
 134                         g_slist_free(analog.channels);
 135                 }
 136         }
 137
 138         /* We count packets even if the temperature was invalid. This way
 139          * a sample limit on "Memory" data source still works: unused
 140          * memory slots come through as "----" measurements. */
 141         devc->num_samples++;
 142         if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
 143                 sdi->driver->dev_acquisition_stop(sdi);
 144         }
 145
 146 }
 147
 148 SR_PRIV void LIBUSB_CALL 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_usb_dev_inst *usb;
 198         struct timeval tv;
 199         int len, ret;
 200         unsigned char cmd[2];
 201
 202         (void)fd;
 203         (void)revents;
 204
 205         if (!(sdi = cb_data))
 206                 return TRUE;
 207
 208         di = sdi->driver;
 209         drvc = di->context;
 210
 211         if (!(devc = sdi->priv))
 212                 return TRUE;
 213
 214         memset(&tv, 0, sizeof(struct timeval));
 215         libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
 216                         NULL);
 217
 218         if (sdi->status == SR_ST_STOPPING) {
 219                 usb_source_remove(sdi->session, drvc->sr_ctx);
 220                 std_session_send_df_header(sdi, LOG_PREFIX);
 221
 222                 /* Tell the device to stop sending USB packets. */
 223                 usb = sdi->conn;
 224                 cmd[0] = 0x01;
 225                 cmd[1] = CMD_STOP;
 226                 ret = libusb_bulk_transfer(usb->devhdl, EP_OUT, cmd, 2, &len, 5);
 227                 if (ret != 0 || len != 2) {
 228                         /* Warning only, doesn't matter. */
 229                         sr_dbg("Failed to send stop command: %s", libusb_error_name(ret));
 230                 }
 231
 232                 sdi->status = SR_ST_ACTIVE;
 233                 return TRUE;
 234         }
 235
 236         return TRUE;
 237 }