src/hardware/gwinstek-gpd/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2018 Bastian Schmitz <bastian.schmitz@udo.edu>
   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 "protocol.h"
  23
  24 SR_PRIV int gpd_send_cmd(struct sr_serial_dev_inst *serial, const char *cmd, ...)
  25 {
  26         int ret;
  27         char cmdbuf[50];
  28         char *cmd_esc;
  29         va_list args;
  30
  31         va_start(args, cmd);
  32         vsnprintf(cmdbuf, sizeof(cmdbuf), cmd, args);
  33         va_end(args);
  34
  35         cmd_esc = g_strescape(cmdbuf, NULL);
  36         sr_dbg("Sending '%s'.", cmd_esc);
  37         g_free(cmd_esc);
  38
  39         ret = serial_write_blocking(serial, cmdbuf, strlen(cmdbuf),
  40                                     serial_timeout(serial, strlen(cmdbuf)));
  41         if (ret < 0) {
  42                 sr_err("Error sending command: %d.", ret);
  43                 return ret;
  44         }
  45
  46         return ret;
  47 }
  48
  49 SR_PRIV int gpd_receive_reply(struct sr_serial_dev_inst *serial, char *buf,
  50                                 int buflen)
  51 {
  52         int l_recv = 0, bufpos = 0, retc, l_startpos = 0, lines = 1;
  53         gint64 start, remaining;
  54         const int timeout_ms = 250;
  55
  56         if (!serial || !buf || (buflen <= 0))
  57                 return SR_ERR_ARG;
  58
  59         start = g_get_monotonic_time();
  60         remaining = timeout_ms;
  61
  62         while ((l_recv < lines) && (bufpos < (buflen + 1))) {
  63                 retc = serial_read_blocking(serial, &buf[bufpos], 1, remaining);
  64                 if (retc != 1)
  65                         return SR_ERR;
  66
  67                 if (bufpos == 0 && buf[bufpos] == '\r')
  68                         continue;
  69                 if (bufpos == 0 && buf[bufpos] == '\n')
  70                         continue;
  71
  72                 if (buf[bufpos] == '\n' || buf[bufpos] == '\r') {
  73                         buf[bufpos] = '\0';
  74                         sr_dbg("Received line '%s'.", &buf[l_startpos]);
  75                         buf[bufpos] = '\n';
  76                         l_startpos = bufpos + 1;
  77                         l_recv++;
  78                 }
  79                 bufpos++;
  80
  81                 /* Reduce timeout by time elapsed. */
  82                 remaining = timeout_ms - ((g_get_monotonic_time() - start) / 1000);
  83                 if (remaining <= 0)
  84                         return SR_ERR; /* Timeout. */
  85         }
  86
  87         buf[bufpos] = '\0';
  88
  89         if (l_recv == lines)
  90                 return SR_OK;
  91         else
  92                 return SR_ERR;
  93 }
  94
  95 SR_PRIV int gpd_receive_data(int fd, int revents, void *cb_data)
  96 {
  97         struct sr_dev_inst *sdi;
  98         struct dev_context *devc;
  99         struct sr_serial_dev_inst *serial;
 100         struct sr_datafeed_packet packet;
 101         struct sr_datafeed_analog analog;
 102         struct sr_analog_encoding encoding;
 103         struct sr_analog_meaning meaning;
 104         struct sr_analog_spec spec;
 105         struct sr_channel *ch;
 106         unsigned int i;
 107         char reply[50];
 108         char *reply_esc;
 109
 110         (void)fd;
 111
 112         if (!(sdi = cb_data))
 113                 return TRUE;
 114
 115         if (!(devc = sdi->priv))
 116                 return TRUE;
 117
 118         serial = sdi->conn;
 119
 120         if (revents == G_IO_IN) {
 121                 if (!devc->reply_pending) {
 122                         sr_err("No reply pending.");
 123                         gpd_receive_reply(serial, reply, sizeof(reply));
 124                         reply_esc = g_strescape(reply, NULL);
 125                         sr_err("Unexpected data '%s'.", reply_esc);
 126                         g_free(reply_esc);
 127                 } else {
 128                         for (i = 0; i < devc->model->num_channels; i++) {
 129                                 packet.type = SR_DF_ANALOG;
 130                                 packet.payload = &analog;
 131
 132                                 reply[0] = '\0';
 133                                 gpd_receive_reply(serial, reply, sizeof(reply));
 134                                 if (sscanf(reply, "%f", &devc->config[i].output_voltage_max) != 1) {
 135                                         sr_err("Invalid reply to VOUT1?: '%s'.",
 136                                                 reply);
 137                                         return TRUE;
 138                                 }
 139
 140                                 /* Send the value forward. */
 141                                 sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
 142                                 analog.num_samples = 1;
 143                                 ch = g_slist_nth_data(sdi->channels, i);
 144                                 analog.meaning->channels =
 145                                         g_slist_append(NULL, ch);
 146                                 analog.meaning->mq = SR_MQ_CURRENT;
 147                                 analog.meaning->unit = SR_UNIT_AMPERE;
 148                                 analog.meaning->mqflags = 0;
 149                                 analog.encoding->digits = 3;
 150                                 analog.spec->spec_digits = 3;
 151                                 analog.data = &devc->config[i].output_current_max;
 152                                 sr_session_send(sdi, &packet);
 153
 154                                 reply[0] = '\0';
 155                                 gpd_receive_reply(serial, reply, sizeof(reply));
 156                                 if (sscanf(reply, "%f", &devc->config[i].output_voltage_max) != 1) {
 157                                         sr_err("Invalid reply to VOUT1?: '%s'.",
 158                                                 reply);
 159                                         return TRUE;
 160                                 }
 161
 162                                 /* Send the value forward. */
 163                                 sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
 164                                 analog.num_samples = 1;
 165                                 ch = g_slist_nth_data(sdi->channels, i);
 166                                 analog.meaning->channels =
 167                                         g_slist_append(NULL, ch);
 168                                 analog.meaning->mq = SR_MQ_VOLTAGE;
 169                                 analog.meaning->unit = SR_UNIT_VOLT;
 170                                 analog.meaning->mqflags = SR_MQFLAG_DC;
 171                                 analog.encoding->digits = 3;
 172                                 analog.spec->spec_digits = 3;
 173                                 analog.data = &devc->config[i].output_voltage_max;
 174                                 sr_session_send(sdi, &packet);
 175                         }
 176
 177                         devc->reply_pending = FALSE;
 178                         sr_sw_limits_update_samples_read(&devc->limits, 1);
 179                 }
 180         } else {
 181                 if (!devc->reply_pending) {
 182                         for (i = 0; i < devc->model->num_channels; i++)
 183                                 gpd_send_cmd(serial, "IOUT%d?\nVOUT%d?\n",
 184                                         i + 1, i + 1);
 185                         devc->req_sent_at = g_get_monotonic_time();
 186                         devc->reply_pending = TRUE;
 187                 }
 188         }
 189
 190         if (sr_sw_limits_check(&devc->limits)) {
 191                 sr_dev_acquisition_stop(sdi);
 192                 return TRUE;
 193         }
 194
 195         return TRUE;
 196 }