hardware/rigol-ds/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2012 Martin Ling <martin-git@earth.li>
   5  * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
   6  * Copyright (C) 2013 Mathias Grimmberger <mgri@zaphod.sax.de>
   7  *
   8  * This program is free software: you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation, either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <stdlib.h>
  23 #include <stdarg.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <string.h>
  27 #include <math.h>
  28 #include <ctype.h>
  29 #include <time.h>
  30 #include <glib.h>
  31 #include "libsigrok.h"
  32 #include "libsigrok-internal.h"
  33 #include "protocol.h"
  34
  35 /*
  36  * This is a unified protocol driver for the DS1000 and DS2000 series.
  37  *
  38  * DS1000 support tested with a Rigol DS1102D.
  39  *
  40  * DS2000 support tested with a Rigol DS2072 using firmware version 01.01.00.02.
  41  *
  42  * The Rigol DS2000 series scopes try to adhere to the IEEE 488.2 (I think)
  43  * standard. If you want to read it - it costs real money...
  44  *
  45  * Every response from the scope has a linefeed appended because the
  46  * standard says so. In principle this could be ignored because sending the
  47  * next command clears the output queue of the scope. This driver tries to
  48  * avoid doing that because it may cause an error being generated inside the
  49  * scope and who knows what bugs the firmware has WRT this.
  50  *
  51  * Waveform data is transferred in a format called "arbitrary block program
  52  * data" specified in IEEE 488.2. See Agilents programming manuals for their
  53  * 2000/3000 series scopes for a nice description.
  54  *
  55  * Each data block from the scope has a header, e.g. "#900000001400".
  56  * The '#' marks the start of a block.
  57  * Next is one ASCII decimal digit between 1 and 9, this gives the number of
  58  * ASCII decimal digits following.
  59  * Last are the ASCII decimal digits giving the number of bytes (not
  60  * samples!) in the block.
  61  *
  62  * After this header as many data bytes as indicated follow.
  63  *
  64  * Each data block has a trailing linefeed too.
  65  */
  66
  67 static int get_cfg(const struct sr_dev_inst *sdi, char *cmd, char *reply, size_t maxlen);
  68 static int get_cfg_int(const struct sr_dev_inst *sdi, char *cmd, int *i);
  69
  70 static int parse_int(const char *str, int *ret)
  71 {
  72         char *e;
  73         long tmp;
  74
  75         errno = 0;
  76         tmp = strtol(str, &e, 10);
  77         if (e == str || *e != '\0') {
  78                 sr_dbg("Failed to parse integer: '%s'", str);
  79                 return SR_ERR;
  80         }
  81         if (errno) {
  82                 sr_dbg("Failed to parse integer: '%s', numerical overflow", str);
  83                 return SR_ERR;
  84         }
  85         if (tmp > INT_MAX || tmp < INT_MIN) {
  86                 sr_dbg("Failed to parse integer: '%s', value to large/small", str);
  87                 return SR_ERR;
  88         }
  89
  90         *ret = (int)tmp;
  91         return SR_OK;
  92 }
  93
  94 /* Set the next event to wait for in rigol_ds_receive */
  95 static void rigol_ds_set_wait_event(struct dev_context *devc, enum wait_events event)
  96 {
  97         if (event == WAIT_STOP)
  98                 devc->wait_status = 2;
  99         else
 100                 devc->wait_status = 1;
 101         devc->wait_event = event;
 102 }
 103
 104 /*
 105  * Waiting for a event will return a timeout after 2 to 3 seconds in order
 106  * to not block the application.
 107  */
 108 static int rigol_ds_event_wait(const struct sr_dev_inst *sdi, char status1, char status2)
 109 {
 110         char buf[20];
 111         struct dev_context *devc;
 112         time_t start;
 113
 114         if (!(devc = sdi->priv))
 115                 return SR_ERR;
 116
 117         start = time(NULL);
 118
 119         /*
 120          * Trigger status may return:
 121          * "TD" or "T'D" - triggered
 122          * "AUTO"        - autotriggered
 123          * "RUN"         - running
 124          * "WAIT"        - waiting for trigger
 125          * "STOP"        - stopped
 126          */
 127
 128         if (devc->wait_status == 1) {
 129                 do {
 130                         if (time(NULL) - start >= 3) {
 131                                 sr_dbg("Timeout waiting for trigger");
 132                                 return SR_ERR_TIMEOUT;
 133                         }
 134
 135                         if (get_cfg(sdi, ":TRIG:STAT?", buf, sizeof(buf)) != SR_OK)
 136                                 return SR_ERR;
 137                 } while (buf[0] == status1 || buf[0] == status2);
 138
 139                 devc->wait_status = 2;
 140         }
 141         if (devc->wait_status == 2) {
 142                 do {
 143                         if (time(NULL) - start >= 3) {
 144                                 sr_dbg("Timeout waiting for trigger");
 145                                 return SR_ERR_TIMEOUT;
 146                         }
 147
 148                         if (get_cfg(sdi, ":TRIG:STAT?", buf, sizeof(buf)) != SR_OK)
 149                                 return SR_ERR;
 150                 } while (buf[0] != status1 && buf[0] != status2);
 151
 152                 rigol_ds_set_wait_event(devc, WAIT_NONE);
 153         }
 154
 155         return SR_OK;
 156 }
 157
 158 /*
 159  * For live capture we need to wait for a new trigger event to ensure that
 160  * sample data is not returned twice.
 161  *
 162  * Unfortunately this will never really work because for sufficiently fast
 163  * timebases and trigger rates it just can't catch the status changes.
 164  *
 165  * What would be needed is a trigger event register with autoreset like the
 166  * Agilents have. The Rigols don't seem to have anything like this.
 167  *
 168  * The workaround is to only wait for the trigger when the timebase is slow
 169  * enough. Of course this means that for faster timebases sample data can be
 170  * returned multiple times, this effect is mitigated somewhat by sleeping
 171  * for about one sweep time in that case.
 172  */
 173 static int rigol_ds_trigger_wait(const struct sr_dev_inst *sdi)
 174 {
 175         struct dev_context *devc;
 176         long s;
 177
 178         if (!(devc = sdi->priv))
 179                 return SR_ERR;
 180
 181         /*
 182          * If timebase < 50 msecs/DIV just sleep about one sweep time except
 183          * for really fast sweeps.
 184          */
 185         if (devc->timebase < 0.0499)
 186         {
 187                 if (devc->timebase > 0.99e-6) {
 188                         /*
 189                          * Timebase * num hor. divs * 85(%) * 1e6(usecs) / 100
 190                          * -> 85 percent of sweep time
 191                          */
 192                         s = (devc->timebase * devc->model->num_horizontal_divs
 193                              * 85e6) / 100L;
 194                         sr_spew("Sleeping for %ld usecs instead of trigger-wait", s);
 195                         g_usleep(s);
 196                 }
 197                 rigol_ds_set_wait_event(devc, WAIT_NONE);
 198                 return SR_OK;
 199         } else {
 200                 return rigol_ds_event_wait(sdi, 'T', 'A');
 201         }
 202 }
 203
 204 /* Wait for scope to got to "Stop" in single shot mode */
 205 static int rigol_ds_stop_wait(const struct sr_dev_inst *sdi)
 206 {
 207         return rigol_ds_event_wait(sdi, 'S', 'S');
 208 }
 209
 210 /* Check that a single shot acquisition actually succeeded on the DS2000 */
 211 static int rigol_ds_check_stop(const struct sr_dev_inst *sdi)
 212 {
 213         struct dev_context *devc;
 214         int tmp;
 215
 216         if (!(devc = sdi->priv))
 217                 return SR_ERR;
 218
 219         if (sr_scpi_send(sdi->conn, ":WAV:SOUR CHAN%d",
 220                           devc->channel_frame->index + 1) != SR_OK)
 221                 return SR_ERR;
 222         /* Check that the number of samples will be accepted */
 223         if (sr_scpi_send(sdi->conn, ":WAV:POIN %d;*OPC", devc->analog_frame_size) != SR_OK)
 224                 return SR_ERR;
 225         if (get_cfg_int(sdi, "*ESR?", &tmp) != SR_OK)
 226                 return SR_ERR;
 227         /*
 228          * If we get an "Execution error" the scope went from "Single" to
 229          * "Stop" without actually triggering. There is no waveform
 230          * displayed and trying to download one will fail - the scope thinks
 231          * it has 1400 samples (like display memory) and the driver thinks
 232          * it has a different number of samples.
 233          *
 234          * In that case just try to capture something again. Might still
 235          * fail in interesting ways.
 236          *
 237          * Ain't firmware fun?
 238          */
 239         if (tmp & 0x10) {
 240                 sr_warn("Single shot acquisition failed, retrying...");
 241                 /* Sleep a bit, otherwise the single shot will often fail */
 242                 g_usleep(500000);
 243                 sr_scpi_send(sdi->conn, ":SING");
 244                 rigol_ds_set_wait_event(devc, WAIT_STOP);
 245                 return SR_ERR;
 246         }
 247
 248         return SR_OK;
 249 }
 250
 251 /* Wait for enough data becoming available in scope output buffer */
 252 static int rigol_ds_block_wait(const struct sr_dev_inst *sdi)
 253 {
 254         char buf[30];
 255         struct dev_context *devc;
 256         time_t start;
 257         int len;
 258
 259         if (!(devc = sdi->priv))
 260                 return SR_ERR;
 261
 262         start = time(NULL);
 263
 264         do {
 265                 if (time(NULL) - start >= 3) {
 266                         sr_dbg("Timeout waiting for data block");
 267                         return SR_ERR_TIMEOUT;
 268                 }
 269
 270                 /*
 271                  * The scope copies data really slowly from sample
 272                  * memory to its output buffer, so try not to bother
 273                  * it too much with SCPI requests but don't wait too
 274                  * long for short sample frame sizes.
 275                  */
 276                 g_usleep(devc->analog_frame_size < 15000 ? 100000 : 1000000);
 277
 278                 /* "READ,nnnn" (still working) or "IDLE,nnnn" (finished) */
 279                 if (get_cfg(sdi, ":WAV:STAT?", buf, sizeof(buf)) != SR_OK)
 280                         return SR_ERR;
 281
 282                 if (parse_int(buf + 5, &len) != SR_OK)
 283                         return SR_ERR;
 284         } while (buf[0] == 'R' && len < 1000000);
 285
 286         rigol_ds_set_wait_event(devc, WAIT_NONE);
 287
 288         return SR_OK;
 289 }
 290
 291 /* Start capturing a new frameset */
 292 SR_PRIV int rigol_ds_capture_start(const struct sr_dev_inst *sdi)
 293 {
 294         struct dev_context *devc;
 295
 296         if (!(devc = sdi->priv))
 297                 return SR_ERR;
 298
 299         sr_dbg("Starting data capture for frameset %lu of %lu",
 300                devc->num_frames + 1, devc->limit_frames);
 301
 302         if (sr_scpi_send(sdi->conn, ":WAV:FORM BYTE") != SR_OK)
 303                 return SR_ERR;
 304         if (devc->data_source == DATA_SOURCE_LIVE) {
 305                 if (sr_scpi_send(sdi->conn, ":WAV:MODE NORM") != SR_OK)
 306                         return SR_ERR;
 307                 rigol_ds_set_wait_event(devc, WAIT_TRIGGER);
 308         } else {
 309                 if (sr_scpi_send(sdi->conn, ":WAV:MODE RAW") != SR_OK)
 310                         return SR_ERR;
 311                 if (sr_scpi_send(sdi->conn, ":SING", devc->analog_frame_size) != SR_OK)
 312                         return SR_ERR;
 313                 rigol_ds_set_wait_event(devc, WAIT_STOP);
 314         }
 315
 316         return SR_OK;
 317 }
 318
 319 /* Start reading data from the current channel */
 320 SR_PRIV int rigol_ds_channel_start(const struct sr_dev_inst *sdi)
 321 {
 322         struct dev_context *devc;
 323
 324         if (!(devc = sdi->priv))
 325                 return SR_ERR;
 326
 327         sr_dbg("Starting reading data from channel %d",
 328                devc->channel_frame->index + 1);
 329
 330         if (sr_scpi_send(sdi->conn, ":WAV:SOUR CHAN%d",
 331                           devc->channel_frame->index + 1) != SR_OK)
 332                 return SR_ERR;
 333         if (devc->data_source != DATA_SOURCE_LIVE) {
 334                 if (sr_scpi_send(sdi->conn, ":WAV:RES") != SR_OK)
 335                         return SR_ERR;
 336                 if (sr_scpi_send(sdi->conn, ":WAV:BEG") != SR_OK)
 337                         return SR_ERR;
 338                 rigol_ds_set_wait_event(devc, WAIT_BLOCK);
 339         } else
 340                 rigol_ds_set_wait_event(devc, WAIT_NONE);
 341
 342         devc->num_frame_bytes = 0;
 343         devc->num_block_bytes = 0;
 344
 345         return SR_OK;
 346 }
 347
 348 /* Read the header of a data block */
 349 static int rigol_ds_read_header(struct sr_scpi_dev_inst *scpi)
 350 {
 351         char start[3], length[10];
 352         int len, tmp;
 353
 354         /* Read the hashsign and length digit. */
 355         tmp = sr_scpi_read(scpi, start, 2);
 356         start[2] = '\0';
 357         if (tmp != 2)
 358         {
 359                 sr_err("Failed to read first two bytes of data block header.");
 360                 return -1;
 361         }
 362         if (start[0] != '#' || !isdigit(start[1]) || start[1] == '0')
 363         {
 364                 sr_err("Received invalid data block header start '%s'.", start);
 365                 return -1;
 366         }
 367         len = atoi(start + 1);
 368
 369         /* Read the data length. */
 370         tmp = sr_scpi_read(scpi, length, len);
 371         length[len] = '\0';
 372         if (tmp != len)
 373         {
 374                 sr_err("Failed to read %d bytes of data block length.", len);
 375                 return -1;
 376         }
 377         if (parse_int(length, &len) != SR_OK)
 378         {
 379                 sr_err("Received invalid data block length '%s'.", length);
 380                 return -1;
 381         }
 382
 383         sr_dbg("Received data block header: %s%s -> block length %d", start, length, len);
 384
 385         return len;
 386 }
 387
 388 SR_PRIV int rigol_ds_receive(int fd, int revents, void *cb_data)
 389 {
 390         struct sr_dev_inst *sdi;
 391         struct sr_scpi_dev_inst *scpi;
 392         struct dev_context *devc;
 393         struct sr_datafeed_packet packet;
 394         struct sr_datafeed_analog analog;
 395         struct sr_datafeed_logic logic;
 396         double vdiv, offset;
 397         int len, i, waveform_size, vref;
 398         struct sr_probe *probe;
 399
 400         (void)fd;
 401
 402         if (!(sdi = cb_data))
 403                 return TRUE;
 404
 405         if (!(devc = sdi->priv))
 406                 return TRUE;
 407
 408         scpi = sdi->conn;
 409
 410         if (revents == G_IO_IN) {
 411                 if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 412                         switch(devc->wait_event) {
 413                         case WAIT_NONE:
 414                                 break;
 415
 416                         case WAIT_TRIGGER:
 417                                 if (rigol_ds_trigger_wait(sdi) != SR_OK)
 418                                         return TRUE;
 419                                 if (rigol_ds_channel_start(sdi) != SR_OK)
 420                                         return TRUE;
 421                                 break;
 422
 423                         case WAIT_BLOCK:
 424                                 if (rigol_ds_block_wait(sdi) != SR_OK)
 425                                         return TRUE;
 426                                 break;
 427
 428                         case WAIT_STOP:
 429                                 if (rigol_ds_stop_wait(sdi) != SR_OK)
 430                                         return TRUE;
 431                                 if (rigol_ds_check_stop(sdi) != SR_OK)
 432                                         return TRUE;
 433                                 if (rigol_ds_channel_start(sdi) != SR_OK)
 434                                         return TRUE;
 435                                 return TRUE;
 436
 437                         default:
 438                                 sr_err("BUG: Unknown event target encountered");
 439                         }
 440
 441                         if (devc->num_block_bytes == 0) {
 442                                 sr_dbg("New block header expected");
 443                                 if (sr_scpi_send(sdi->conn, ":WAV:DATA?") != SR_OK)
 444                                         return TRUE;
 445                                 len = rigol_ds_read_header(scpi);
 446                                 if (len == -1)
 447                                         return TRUE;
 448                                 /* At slow timebases in live capture the DS2072
 449                                  * sometimes returns "short" data blocks, with
 450                                  * apparently no way to get the rest of the data.
 451                                  * Discard these, the complete data block will
 452                                  * appear eventually.
 453                                  */
 454                                 if (devc->data_source == DATA_SOURCE_LIVE
 455                                     && (unsigned)len < devc->num_frame_bytes) {
 456                                         sr_dbg("Discarding short data block");
 457                                         sr_scpi_read(scpi, (char *)devc->buffer, len + 1);
 458                                         return TRUE;
 459                                 }
 460                                 devc->num_block_bytes = len;
 461                                 devc->num_block_read = 0;
 462                         }
 463                 }
 464
 465                 probe = devc->channel_frame;
 466                 if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 467                         len = devc->num_block_bytes - devc->num_block_read;
 468                         len = sr_scpi_read(scpi, (char *)devc->buffer,
 469                                         len < ACQ_BUFFER_SIZE ? len : ACQ_BUFFER_SIZE);
 470                 } else {
 471                         waveform_size = probe->type == SR_PROBE_ANALOG ?
 472                                         DS1000_ANALOG_LIVE_WAVEFORM_SIZE : DIGITAL_WAVEFORM_SIZE;
 473                         len = sr_scpi_read(scpi, (char *)devc->buffer,
 474                                         waveform_size - devc->num_frame_bytes);
 475                 }
 476                 sr_dbg("Received %d bytes.", len);
 477                 if (len == -1)
 478                         return TRUE;
 479
 480                 if (devc->num_frame_bytes == 0) {
 481                         /* Start of a new frame. */
 482                         packet.type = SR_DF_FRAME_BEGIN;
 483                         sr_session_send(sdi, &packet);
 484                 }
 485
 486                 if (probe->type == SR_PROBE_ANALOG) {
 487                         if (devc->model->protocol == PROTOCOL_IEEE488_2)
 488                                 devc->num_block_read += len;
 489                         vref = devc->vert_reference[probe->index];
 490                         vdiv = devc->vdiv[probe->index] / 25.6;
 491                         offset = devc->vert_offset[probe->index];
 492                         if (devc->model->protocol == PROTOCOL_IEEE488_2)
 493                                 for (i = 0; i < len; i++)
 494                                         devc->data[i] = ((int)devc->buffer[i] - vref) * vdiv - offset;
 495                         else
 496                                 for (i = 0; i < len; i++)
 497                                         devc->data[i] = (128 - devc->buffer[i]) * vdiv - offset;
 498                         analog.probes = g_slist_append(NULL, probe);
 499                         analog.num_samples = len;
 500                         analog.data = devc->data;
 501                         analog.mq = SR_MQ_VOLTAGE;
 502                         analog.unit = SR_UNIT_VOLT;
 503                         analog.mqflags = 0;
 504                         packet.type = SR_DF_ANALOG;
 505                         packet.payload = &analog;
 506                         sr_session_send(cb_data, &packet);
 507                         g_slist_free(analog.probes);
 508
 509                         if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 510                                 if (devc->num_block_read == devc->num_block_bytes) {
 511                                         sr_dbg("Block has been completed");
 512                                         /* Discard the terminating linefeed and prepare for
 513                                            possible next block */
 514                                         sr_scpi_read(scpi, (char *)devc->buffer, 1);
 515                                         devc->num_block_bytes = 0;
 516                                         if (devc->data_source != DATA_SOURCE_LIVE)
 517                                                 rigol_ds_set_wait_event(devc, WAIT_BLOCK);
 518                                 } else
 519                                         sr_dbg("%d of %d block bytes read", devc->num_block_read, devc->num_block_bytes);
 520                         }
 521
 522                         devc->num_frame_bytes += len;
 523
 524                         if (devc->num_frame_bytes < devc->analog_frame_size)
 525                                 /* Don't have the whole frame yet. */
 526                                 return TRUE;
 527
 528                         sr_dbg("Frame completed, %d samples", devc->num_frame_bytes);
 529                 } else {
 530                         logic.length = len - 10;
 531                         logic.unitsize = 2;
 532                         logic.data = devc->buffer + 10;
 533                         packet.type = SR_DF_LOGIC;
 534                         packet.payload = &logic;
 535                         sr_session_send(cb_data, &packet);
 536
 537                         if (len != DIGITAL_WAVEFORM_SIZE)
 538                                 /* Don't have the whole frame yet. */
 539                                 return TRUE;
 540                 }
 541
 542                 /* End of the frame. */
 543                 packet.type = SR_DF_FRAME_END;
 544                 sr_session_send(sdi, &packet);
 545                 if (devc->model->protocol == PROTOCOL_LEGACY)
 546                         devc->num_frame_bytes = 0;
 547                 else {
 548                         /* Signal end of data download to scope */
 549                         if (devc->data_source != DATA_SOURCE_LIVE)
 550                                 /*
 551                                  * This causes a query error, without it switching
 552                                  * to the next channel causes an error. Fun with
 553                                  * firmware...
 554                                  */
 555                                 sr_scpi_send(sdi->conn, ":WAV:END");
 556                 }
 557
 558                 if (devc->enabled_analog_probes
 559                                 && devc->channel_frame == devc->enabled_analog_probes->data
 560                                 && devc->enabled_analog_probes->next != NULL) {
 561                         /* We got the frame for the first analog channel, but
 562                          * there's a second analog channel. */
 563                         devc->channel_frame = devc->enabled_analog_probes->next->data;
 564                         if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 565                                 rigol_ds_channel_start(sdi);
 566                         } else {
 567                                 sr_scpi_send(sdi->conn, ":WAV:DATA? CHAN%c",
 568                                                 devc->channel_frame->name[2]);
 569                         }
 570                 } else {
 571                         /* Done with both analog channels in this frame. */
 572                         if (devc->enabled_digital_probes
 573                                         && devc->channel_frame != devc->enabled_digital_probes->data) {
 574                                 /* Now we need to get the digital data. */
 575                                 devc->channel_frame = devc->enabled_digital_probes->data;
 576                                 sr_scpi_send(sdi->conn, ":WAV:DATA? DIG");
 577                         } else if (++devc->num_frames == devc->limit_frames) {
 578                                 /* End of last frame. */
 579                                 packet.type = SR_DF_END;
 580                                 sr_session_send(sdi, &packet);
 581                                 sdi->driver->dev_acquisition_stop(sdi, cb_data);
 582                         } else {
 583                                 /* Get the next frame, starting with the first analog channel. */
 584                                 if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 585                                         if (devc->enabled_analog_probes) {
 586                                                 devc->channel_frame = devc->enabled_analog_probes->data;
 587                                                 rigol_ds_capture_start(sdi);
 588                                         }
 589                                 } else {
 590                                         if (devc->enabled_analog_probes) {
 591                                                 devc->channel_frame = devc->enabled_analog_probes->data;
 592                                                 sr_scpi_send(sdi->conn, ":WAV:DATA? CHAN%c",
 593                                                                 devc->channel_frame->name[2]);
 594                                         } else {
 595                                                 devc->channel_frame = devc->enabled_digital_probes->data;
 596                                                 sr_scpi_send(sdi->conn, ":WAV:DATA? DIG");
 597                                         }
 598                                 }
 599                         }
 600                 }
 601         }
 602
 603         return TRUE;
 604 }
 605
 606 static int get_cfg(const struct sr_dev_inst *sdi, char *cmd, char *reply, size_t maxlen)
 607 {
 608         int len;
 609         struct dev_context *devc = sdi->priv;
 610         struct sr_scpi_dev_inst *scpi = sdi->conn;
 611         char *response;
 612
 613         if (sr_scpi_send(scpi, cmd) != SR_OK)
 614                 return SR_ERR;
 615
 616         if (sr_scpi_receive(scpi, &response) != SR_OK)
 617                 return SR_ERR;
 618
 619         g_strlcpy(reply, response, maxlen);
 620         g_free(response);
 621         len = strlen(reply);
 622
 623         if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 624                 /* get rid of trailing linefeed */
 625                 if (len >= 1 && reply[len-1] == '\n')
 626                         reply[len-1] = '\0';
 627         }
 628
 629         sr_spew("Received '%s'.", reply);
 630
 631         return SR_OK;
 632 }
 633
 634 static int get_cfg_int(const struct sr_dev_inst *sdi, char *cmd, int *i)
 635 {
 636         char buf[32];
 637
 638         if (get_cfg(sdi, cmd, buf, sizeof(buf)) != SR_OK)
 639                 return SR_ERR;
 640
 641         if (parse_int(buf, i) != SR_OK)
 642                 return SR_ERR;
 643
 644         return SR_OK;
 645 }
 646
 647 static int get_cfg_float(const struct sr_dev_inst *sdi, char *cmd, float *f)
 648 {
 649         char buf[32], *e;
 650
 651         if (get_cfg(sdi, cmd, buf, sizeof(buf)) != SR_OK)
 652                 return SR_ERR;
 653         *f = strtof(buf, &e);
 654         if (e == buf || (fpclassify(*f) & (FP_ZERO | FP_NORMAL)) == 0) {
 655                 sr_dbg("failed to parse response to '%s': '%s'", cmd, buf);
 656                 return SR_ERR;
 657         }
 658
 659         return SR_OK;
 660 }
 661
 662 static int get_cfg_string(const struct sr_dev_inst *sdi, char *cmd, char **buf)
 663 {
 664         if (!(*buf = g_try_malloc0(256)))
 665                 return SR_ERR_MALLOC;
 666
 667         if (get_cfg(sdi, cmd, *buf, 256) != SR_OK)
 668                 return SR_ERR;
 669
 670         return SR_OK;
 671 }
 672
 673 SR_PRIV int rigol_ds_get_dev_cfg(const struct sr_dev_inst *sdi)
 674 {
 675         struct dev_context *devc;
 676         char *t_s, *cmd;
 677         int i, res;
 678
 679         devc = sdi->priv;
 680
 681         /* Analog channel state. */
 682         if (get_cfg_string(sdi, ":CHAN1:DISP?", &t_s) != SR_OK)
 683                 return SR_ERR;
 684         devc->analog_channels[0] = !strcmp(t_s, "ON") || !strcmp(t_s, "1");
 685         g_free(t_s);
 686         if (get_cfg_string(sdi, ":CHAN2:DISP?", &t_s) != SR_OK)
 687                 return SR_ERR;
 688         devc->analog_channels[1] = !strcmp(t_s, "ON") || !strcmp(t_s, "1");
 689         g_free(t_s);
 690         sr_dbg("Current analog channel state CH1 %s CH2 %s",
 691                         devc->analog_channels[0] ? "on" : "off",
 692                         devc->analog_channels[1] ? "on" : "off");
 693
 694         /* Digital channel state. */
 695         if (devc->model->has_digital) {
 696                 sr_dbg("Current digital channel state:");
 697                 for (i = 0; i < 16; i++) {
 698                         cmd = g_strdup_printf(":DIG%d:TURN?", i);
 699                         res = get_cfg_string(sdi, cmd, &t_s);
 700                         g_free(cmd);
 701                         if (res != SR_OK)
 702                                 return SR_ERR;
 703                         devc->digital_channels[i] = !strcmp(t_s, "ON") ? TRUE : FALSE;
 704                         g_free(t_s);
 705                         sr_dbg("D%d: %s", i, devc->digital_channels[i] ? "on" : "off");
 706                 }
 707         }
 708
 709         /* Timebase. */
 710         if (get_cfg_float(sdi, ":TIM:SCAL?", &devc->timebase) != SR_OK)
 711                 return SR_ERR;
 712         sr_dbg("Current timebase %g", devc->timebase);
 713
 714         /* Vertical gain. */
 715         if (get_cfg_float(sdi, ":CHAN1:SCAL?", &devc->vdiv[0]) != SR_OK)
 716                 return SR_ERR;
 717         if (get_cfg_float(sdi, ":CHAN2:SCAL?", &devc->vdiv[1]) != SR_OK)
 718                 return SR_ERR;
 719         sr_dbg("Current vertical gain CH1 %g CH2 %g", devc->vdiv[0], devc->vdiv[1]);
 720
 721         if (devc->model->protocol == PROTOCOL_IEEE488_2) {
 722                 /* Vertical reference - not certain if this is the place to read it. */
 723                 if (sr_scpi_send(sdi->conn, ":WAV:SOUR CHAN1") != SR_OK)
 724                         return SR_ERR;
 725                 if (get_cfg_int(sdi, ":WAV:YREF?", &devc->vert_reference[0]) != SR_OK)
 726                         return SR_ERR;
 727                 if (sr_scpi_send(sdi->conn, ":WAV:SOUR CHAN2") != SR_OK)
 728                         return SR_ERR;
 729                 if (get_cfg_int(sdi, ":WAV:YREF?", &devc->vert_reference[1]) != SR_OK)
 730                         return SR_ERR;
 731                 sr_dbg("Current vertical reference CH1 %d CH2 %d",
 732                                 devc->vert_reference[0], devc->vert_reference[1]);
 733         }
 734
 735         /* Vertical offset. */
 736         if (get_cfg_float(sdi, ":CHAN1:OFFS?", &devc->vert_offset[0]) != SR_OK)
 737                 return SR_ERR;
 738         if (get_cfg_float(sdi, ":CHAN2:OFFS?", &devc->vert_offset[1]) != SR_OK)
 739                 return SR_ERR;
 740         sr_dbg("Current vertical offset CH1 %g CH2 %g", devc->vert_offset[0],
 741                         devc->vert_offset[1]);
 742
 743         /* Coupling. */
 744         if (get_cfg_string(sdi, ":CHAN1:COUP?", &devc->coupling[0]) != SR_OK)
 745                 return SR_ERR;
 746         if (get_cfg_string(sdi, ":CHAN2:COUP?", &devc->coupling[1]) != SR_OK)
 747                 return SR_ERR;
 748         sr_dbg("Current coupling CH1 %s CH2 %s", devc->coupling[0],
 749                         devc->coupling[1]);
 750
 751         /* Trigger source. */
 752         if (get_cfg_string(sdi, ":TRIG:EDGE:SOUR?", &devc->trigger_source) != SR_OK)
 753                 return SR_ERR;
 754         sr_dbg("Current trigger source %s", devc->trigger_source);
 755
 756         /* Horizontal trigger position. */
 757         if (get_cfg_float(sdi, ":TIM:OFFS?", &devc->horiz_triggerpos) != SR_OK)
 758                 return SR_ERR;
 759         sr_dbg("Current horizontal trigger position %g", devc->horiz_triggerpos);
 760
 761         /* Trigger slope. */
 762         if (get_cfg_string(sdi, ":TRIG:EDGE:SLOP?", &devc->trigger_slope) != SR_OK)
 763                 return SR_ERR;
 764         sr_dbg("Current trigger slope %s", devc->trigger_slope);
 765
 766         return SR_OK;
 767 }