src/hardware/scpi-pps/api.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 <config.h>
  21 #include <string.h>
  22 #include <strings.h>
  23 #include "scpi.h"
  24 #include "protocol.h"
  25
  26 SR_PRIV struct sr_dev_driver scpi_pps_driver_info;
  27
  28 static const uint32_t scanopts[] = {
  29         SR_CONF_CONN,
  30         SR_CONF_SERIALCOMM,
  31 };
  32
  33 static const uint32_t drvopts[] = {
  34         SR_CONF_POWER_SUPPLY,
  35 };
  36
  37 static const struct pps_channel_instance pci[] = {
  38         { SR_MQ_VOLTAGE, SCPI_CMD_GET_MEAS_VOLTAGE, "V" },
  39         { SR_MQ_CURRENT, SCPI_CMD_GET_MEAS_CURRENT, "I" },
  40         { SR_MQ_POWER, SCPI_CMD_GET_MEAS_POWER, "P" },
  41         { SR_MQ_FREQUENCY, SCPI_CMD_GET_MEAS_FREQUENCY, "F" },
  42 };
  43
  44 static int init(struct sr_dev_driver *di, struct sr_context *sr_ctx)
  45 {
  46         return std_init(sr_ctx, di, LOG_PREFIX);
  47 }
  48
  49 static struct sr_dev_inst *probe_device(struct sr_scpi_dev_inst *scpi)
  50 {
  51         struct dev_context *devc;
  52         struct sr_dev_inst *sdi;
  53         struct sr_scpi_hw_info *hw_info;
  54         struct sr_channel_group *cg;
  55         struct sr_channel *ch;
  56         const struct scpi_pps *device;
  57         struct pps_channel *pch;
  58         struct channel_spec *channels;
  59         struct channel_group_spec *channel_groups, *cgs;
  60         struct pps_channel_group *pcg;
  61         GRegex *model_re;
  62         GMatchInfo *model_mi;
  63         GSList *l;
  64         uint64_t mask;
  65         unsigned int num_channels, num_channel_groups, ch_num, ch_idx, i, j;
  66         int ret;
  67         const char *vendor;
  68         char ch_name[16];
  69
  70         if (sr_scpi_get_hw_id(scpi, &hw_info) != SR_OK) {
  71                 sr_info("Couldn't get IDN response.");
  72                 return NULL;
  73         }
  74
  75         device = NULL;
  76         for (i = 0; i < num_pps_profiles; i++) {
  77                 vendor = sr_vendor_alias(hw_info->manufacturer);
  78                 if (g_ascii_strcasecmp(vendor, pps_profiles[i].vendor))
  79                         continue;
  80                 model_re = g_regex_new(pps_profiles[i].model, 0, 0, NULL);
  81                 if (g_regex_match(model_re, hw_info->model, 0, &model_mi))
  82                         device = &pps_profiles[i];
  83                 g_match_info_unref(model_mi);
  84                 g_regex_unref(model_re);
  85                 if (device)
  86                         break;
  87         }
  88         if (!device) {
  89                 sr_scpi_hw_info_free(hw_info);
  90                 return NULL;
  91         }
  92
  93         sdi = g_malloc0(sizeof(struct sr_dev_inst));
  94         sdi->vendor = g_strdup(vendor);
  95         sdi->model = g_strdup(hw_info->model);
  96         sdi->version = g_strdup(hw_info->firmware_version);
  97         sdi->conn = scpi;
  98         sdi->driver = &scpi_pps_driver_info;
  99         sdi->inst_type = SR_INST_SCPI;
 100         sdi->serial_num = g_strdup(hw_info->serial_number);
 101
 102         devc = g_malloc0(sizeof(struct dev_context));
 103         devc->device = device;
 104         sdi->priv = devc;
 105
 106         if (device->num_channels) {
 107                 /* Static channels and groups. */
 108                 channels = (struct channel_spec *)device->channels;
 109                 num_channels = device->num_channels;
 110                 channel_groups = (struct channel_group_spec *)device->channel_groups;
 111                 num_channel_groups = device->num_channel_groups;
 112         } else {
 113                 /* Channels and groups need to be probed. */
 114                 ret = device->probe_channels(sdi, hw_info, &channels, &num_channels,
 115                                 &channel_groups, &num_channel_groups);
 116                 if (ret != SR_OK) {
 117                         sr_err("Failed to probe for channels.");
 118                         return NULL;
 119                 }
 120                 /*
 121                  * Since these were dynamically allocated, we'll need to free them
 122                  * later.
 123                  */
 124                 devc->channels = channels;
 125                 devc->channel_groups = channel_groups;
 126         }
 127
 128         ch_idx = 0;
 129         for (ch_num = 0; ch_num < num_channels; ch_num++) {
 130                 /* Create one channel per measurable output unit. */
 131                 for (i = 0; i < ARRAY_SIZE(pci); i++) {
 132                         if (!scpi_cmd_get(devc->device->commands, pci[i].command))
 133                                 continue;
 134                         g_snprintf(ch_name, 16, "%s%s", pci[i].prefix,
 135                                         channels[ch_num].name);
 136                         ch = sr_channel_new(sdi, ch_idx++, SR_CHANNEL_ANALOG, TRUE,
 137                                         ch_name);
 138                         pch = g_malloc0(sizeof(struct pps_channel));
 139                         pch->hw_output_idx = ch_num;
 140                         pch->hwname = channels[ch_num].name;
 141                         pch->mq = pci[i].mq;
 142                         ch->priv = pch;
 143                 }
 144         }
 145
 146         for (i = 0; i < num_channel_groups; i++) {
 147                 cgs = &channel_groups[i];
 148                 cg = g_malloc0(sizeof(struct sr_channel_group));
 149                 cg->name = g_strdup(cgs->name);
 150                 for (j = 0, mask = 1; j < 64; j++, mask <<= 1) {
 151                         if (cgs->channel_index_mask & mask) {
 152                                 for (l = sdi->channels; l; l = l->next) {
 153                                         ch = l->data;
 154                                         pch = ch->priv;
 155                                         if (pch->hw_output_idx == j)
 156                                                 cg->channels = g_slist_append(cg->channels, ch);
 157                                 }
 158                         }
 159                 }
 160                 pcg = g_malloc0(sizeof(struct pps_channel_group));
 161                 pcg->features = cgs->features;
 162                 cg->priv = pcg;
 163                 sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
 164         }
 165
 166         sr_scpi_hw_info_free(hw_info);
 167         hw_info = NULL;
 168
 169         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_LOCAL);
 170
 171         return sdi;
 172 }
 173
 174 static GSList *scan(struct sr_dev_driver *di, GSList *options)
 175 {
 176         return sr_scpi_scan(di->context, options, probe_device);
 177 }
 178
 179 static GSList *dev_list(const struct sr_dev_driver *di)
 180 {
 181         return ((struct drv_context *)(di->context))->instances;
 182 }
 183
 184 static int dev_open(struct sr_dev_inst *sdi)
 185 {
 186         struct dev_context *devc;
 187         struct sr_scpi_dev_inst *scpi;
 188         GVariant *beeper;
 189
 190         if (sdi->status != SR_ST_INACTIVE)
 191                 return SR_ERR;
 192
 193         scpi = sdi->conn;
 194         if (sr_scpi_open(scpi) < 0)
 195                 return SR_ERR;
 196
 197         sdi->status = SR_ST_ACTIVE;
 198
 199         devc = sdi->priv;
 200         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_REMOTE);
 201         devc->beeper_was_set = FALSE;
 202         if (scpi_cmd_resp(sdi, devc->device->commands, &beeper,
 203                         G_VARIANT_TYPE_BOOLEAN, SCPI_CMD_BEEPER) == SR_OK) {
 204                 if (g_variant_get_boolean(beeper)) {
 205                         devc->beeper_was_set = TRUE;
 206                         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_BEEPER_DISABLE);
 207                 }
 208                 g_variant_unref(beeper);
 209         }
 210
 211         return SR_OK;
 212 }
 213
 214 static int dev_close(struct sr_dev_inst *sdi)
 215 {
 216         struct sr_scpi_dev_inst *scpi;
 217         struct dev_context *devc;
 218
 219         if (sdi->status != SR_ST_ACTIVE)
 220                 return SR_ERR_DEV_CLOSED;
 221
 222         devc = sdi->priv;
 223         scpi = sdi->conn;
 224         if (scpi) {
 225                 if (devc->beeper_was_set)
 226                         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_BEEPER_ENABLE);
 227                 scpi_cmd(sdi, devc->device->commands, SCPI_CMD_LOCAL);
 228                 sr_scpi_close(scpi);
 229                 sdi->status = SR_ST_INACTIVE;
 230         }
 231
 232         return SR_OK;
 233 }
 234
 235 static void clear_helper(void *priv)
 236 {
 237         struct dev_context *devc;
 238
 239         devc = priv;
 240         g_free(devc->channels);
 241         g_free(devc->channel_groups);
 242         g_free(devc);
 243 }
 244
 245 static int dev_clear(const struct sr_dev_driver *di)
 246 {
 247         return std_dev_clear(di, clear_helper);
 248 }
 249
 250 static int cleanup(const struct sr_dev_driver *di)
 251 {
 252         return dev_clear(di);
 253 }
 254
 255 static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
 256                 const struct sr_channel_group *cg)
 257 {
 258         struct dev_context *devc;
 259         const GVariantType *gvtype;
 260         unsigned int i;
 261         int cmd, ret;
 262         const char *s;
 263
 264         if (!sdi)
 265                 return SR_ERR_ARG;
 266
 267         devc = sdi->priv;
 268
 269         if (cg) {
 270                 /*
 271                  * These options only apply to channel groups with a single
 272                  * channel -- they're per-channel settings for the device.
 273                  */
 274
 275                 /*
 276                  * Config keys are handled below depending on whether a channel
 277                  * group was provided by the frontend. However some of these
 278                  * take a CG on one PPS but not on others. Check the device's
 279                  * profile for that here, and NULL out the channel group as needed.
 280                  */
 281                 for (i = 0; i < devc->device->num_devopts; i++) {
 282                         if (devc->device->devopts[i] == key) {
 283                                 cg = NULL;
 284                                 break;
 285                         }
 286                 }
 287         }
 288
 289         gvtype = NULL;
 290         cmd = -1;
 291         switch (key) {
 292         case SR_CONF_ENABLED:
 293                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 294                 cmd = SCPI_CMD_GET_OUTPUT_ENABLED;
 295                 break;
 296         case SR_CONF_VOLTAGE:
 297                 gvtype = G_VARIANT_TYPE_DOUBLE;
 298                 cmd = SCPI_CMD_GET_MEAS_VOLTAGE;
 299                 break;
 300         case SR_CONF_VOLTAGE_TARGET:
 301                 gvtype = G_VARIANT_TYPE_DOUBLE;
 302                 cmd = SCPI_CMD_GET_VOLTAGE_TARGET;
 303                 break;
 304         case SR_CONF_OUTPUT_FREQUENCY:
 305                 gvtype = G_VARIANT_TYPE_DOUBLE;
 306                 cmd = SCPI_CMD_GET_MEAS_FREQUENCY;
 307                 break;
 308         case SR_CONF_OUTPUT_FREQUENCY_TARGET:
 309                 gvtype = G_VARIANT_TYPE_DOUBLE;
 310                 cmd = SCPI_CMD_GET_FREQUENCY_TARGET;
 311                 break;
 312         case SR_CONF_CURRENT:
 313                 gvtype = G_VARIANT_TYPE_DOUBLE;
 314                 cmd = SCPI_CMD_GET_MEAS_CURRENT;
 315                 break;
 316         case SR_CONF_CURRENT_LIMIT:
 317                 gvtype = G_VARIANT_TYPE_DOUBLE;
 318                 cmd = SCPI_CMD_GET_CURRENT_LIMIT;
 319                 break;
 320         case SR_CONF_OVER_VOLTAGE_PROTECTION_ENABLED:
 321                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 322                 cmd = SCPI_CMD_GET_OVER_VOLTAGE_PROTECTION_ENABLED;
 323                 break;
 324         case SR_CONF_OVER_VOLTAGE_PROTECTION_ACTIVE:
 325                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 326                 cmd = SCPI_CMD_GET_OVER_VOLTAGE_PROTECTION_ACTIVE;
 327                 break;
 328         case SR_CONF_OVER_VOLTAGE_PROTECTION_THRESHOLD:
 329                 gvtype = G_VARIANT_TYPE_DOUBLE;
 330                 cmd = SCPI_CMD_GET_OVER_VOLTAGE_PROTECTION_THRESHOLD;
 331                 break;
 332         case SR_CONF_OVER_CURRENT_PROTECTION_ENABLED:
 333                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 334                 cmd = SCPI_CMD_GET_OVER_CURRENT_PROTECTION_ENABLED;
 335                 break;
 336         case SR_CONF_OVER_CURRENT_PROTECTION_ACTIVE:
 337                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 338                 cmd = SCPI_CMD_GET_OVER_CURRENT_PROTECTION_ACTIVE;
 339                 break;
 340         case SR_CONF_OVER_CURRENT_PROTECTION_THRESHOLD:
 341                 gvtype = G_VARIANT_TYPE_DOUBLE;
 342                 cmd = SCPI_CMD_GET_OVER_CURRENT_PROTECTION_THRESHOLD;
 343                 break;
 344         case SR_CONF_OVER_TEMPERATURE_PROTECTION:
 345                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 346                 cmd = SCPI_CMD_GET_OVER_TEMPERATURE_PROTECTION;
 347                 break;
 348         case SR_CONF_REGULATION:
 349                 gvtype = G_VARIANT_TYPE_STRING;
 350                 cmd = SCPI_CMD_GET_OUTPUT_REGULATION;
 351         }
 352         if (!gvtype)
 353                 return SR_ERR_NA;
 354
 355         if (cg)
 356                 select_channel(sdi, cg->channels->data);
 357         ret = scpi_cmd_resp(sdi, devc->device->commands, data, gvtype, cmd);
 358
 359         if (cmd == SCPI_CMD_GET_OUTPUT_REGULATION) {
 360                 /*
 361                  * The Rigol DP800 series return CV/CC/UR, Philips PM2800
 362                  * return VOLT/CURR. We always return a GVariant string in
 363                  * the Rigol notation.
 364                  */
 365                 s = g_variant_get_string(*data, NULL);
 366                 if (!strcmp(s, "VOLT")) {
 367                         g_variant_unref(*data);
 368                         *data = g_variant_new_string("CV");
 369                 } else if (!strcmp(s, "CURR")) {
 370                         g_variant_unref(*data);
 371                         *data = g_variant_new_string("CC");
 372                 }
 373
 374                 s = g_variant_get_string(*data, NULL);
 375                 if (strcmp(s, "CV") && strcmp(s, "CC") && strcmp(s, "UR")) {
 376                         sr_dbg("Unknown response to SCPI_CMD_GET_OUTPUT_REGULATION: %s", s);
 377                         ret = SR_ERR_DATA;
 378                 }
 379         }
 380
 381         return ret;
 382 }
 383
 384 static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sdi,
 385                 const struct sr_channel_group *cg)
 386 {
 387         struct dev_context *devc;
 388         double d;
 389         int ret;
 390
 391         if (!sdi)
 392                 return SR_ERR_ARG;
 393
 394         if (sdi->status != SR_ST_ACTIVE)
 395                 return SR_ERR_DEV_CLOSED;
 396
 397         if (cg)
 398                 /* Channel group specified. */
 399                 select_channel(sdi, cg->channels->data);
 400
 401         devc = sdi->priv;
 402
 403         switch (key) {
 404         case SR_CONF_ENABLED:
 405                 if (g_variant_get_boolean(data))
 406                         ret = scpi_cmd(sdi, devc->device->commands,
 407                                         SCPI_CMD_SET_OUTPUT_ENABLE);
 408                 else
 409                         ret = scpi_cmd(sdi, devc->device->commands,
 410                                         SCPI_CMD_SET_OUTPUT_DISABLE);
 411                 break;
 412         case SR_CONF_VOLTAGE_TARGET:
 413                 d = g_variant_get_double(data);
 414                 ret = scpi_cmd(sdi, devc->device->commands,
 415                                 SCPI_CMD_SET_VOLTAGE_TARGET, d);
 416                 break;
 417         case SR_CONF_OUTPUT_FREQUENCY_TARGET:
 418                 d = g_variant_get_double(data);
 419                 ret = scpi_cmd(sdi, devc->device->commands,
 420                                 SCPI_CMD_SET_FREQUENCY_TARGET, d);
 421                 break;
 422         case SR_CONF_CURRENT_LIMIT:
 423                 d = g_variant_get_double(data);
 424                 ret = scpi_cmd(sdi, devc->device->commands,
 425                                 SCPI_CMD_SET_CURRENT_LIMIT, d);
 426                 break;
 427         case SR_CONF_OVER_VOLTAGE_PROTECTION_ENABLED:
 428                 if (g_variant_get_boolean(data))
 429                         ret = scpi_cmd(sdi, devc->device->commands,
 430                                         SCPI_CMD_SET_OVER_VOLTAGE_PROTECTION_ENABLE);
 431                 else
 432                         ret = scpi_cmd(sdi, devc->device->commands,
 433                                         SCPI_CMD_SET_OVER_VOLTAGE_PROTECTION_DISABLE);
 434                 break;
 435         case SR_CONF_OVER_VOLTAGE_PROTECTION_THRESHOLD:
 436                 d = g_variant_get_double(data);
 437                 ret = scpi_cmd(sdi, devc->device->commands,
 438                                 SCPI_CMD_SET_OVER_VOLTAGE_PROTECTION_THRESHOLD, d);
 439                 break;
 440         case SR_CONF_OVER_CURRENT_PROTECTION_ENABLED:
 441                 if (g_variant_get_boolean(data))
 442                         ret = scpi_cmd(sdi, devc->device->commands,
 443                                         SCPI_CMD_SET_OVER_CURRENT_PROTECTION_ENABLE);
 444                 else
 445                         ret = scpi_cmd(sdi, devc->device->commands,
 446                                         SCPI_CMD_SET_OVER_CURRENT_PROTECTION_DISABLE);
 447                 break;
 448         case SR_CONF_OVER_CURRENT_PROTECTION_THRESHOLD:
 449                 d = g_variant_get_double(data);
 450                 ret = scpi_cmd(sdi, devc->device->commands,
 451                                 SCPI_CMD_SET_OVER_CURRENT_PROTECTION_THRESHOLD, d);
 452                 break;
 453         case SR_CONF_OVER_TEMPERATURE_PROTECTION:
 454                 if (g_variant_get_boolean(data))
 455                         ret = scpi_cmd(sdi, devc->device->commands,
 456                                         SCPI_CMD_SET_OVER_TEMPERATURE_PROTECTION_ENABLE);
 457                 else
 458                         ret = scpi_cmd(sdi, devc->device->commands,
 459                                         SCPI_CMD_SET_OVER_TEMPERATURE_PROTECTION_DISABLE);
 460                 break;
 461         default:
 462                 ret = SR_ERR_NA;
 463         }
 464
 465         return ret;
 466 }
 467
 468 static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
 469                 const struct sr_channel_group *cg)
 470 {
 471         struct dev_context *devc;
 472         struct sr_channel *ch;
 473         const struct channel_spec *ch_spec;
 474         GVariant *gvar;
 475         GVariantBuilder gvb;
 476         int ret, i;
 477         const char *s[16];
 478
 479         /* Always available, even without sdi. */
 480         if (key == SR_CONF_SCAN_OPTIONS) {
 481                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 482                                 scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
 483                 return SR_OK;
 484         } else if (key == SR_CONF_DEVICE_OPTIONS && !sdi) {
 485                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 486                                 drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
 487                 return SR_OK;
 488         }
 489
 490         if (!sdi)
 491                 return SR_ERR_ARG;
 492         devc = sdi->priv;
 493
 494         ret = SR_OK;
 495         if (!cg) {
 496                 /* No channel group: global options. */
 497                 switch (key) {
 498                 case SR_CONF_DEVICE_OPTIONS:
 499                         *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 500                                         devc->device->devopts, devc->device->num_devopts,
 501                                         sizeof(uint32_t));
 502                         break;
 503                 case SR_CONF_CHANNEL_CONFIG:
 504                         /* Not used. */
 505                         i = 0;
 506                         if (devc->device->features & PPS_INDEPENDENT)
 507                                 s[i++] = "Independent";
 508                         if (devc->device->features & PPS_SERIES)
 509                                 s[i++] = "Series";
 510                         if (devc->device->features & PPS_PARALLEL)
 511                                 s[i++] = "Parallel";
 512                         if (i == 0) {
 513                                 /*
 514                                  * Shouldn't happen: independent-only devices
 515                                  * shouldn't advertise this option at all.
 516                                  */
 517                                 return SR_ERR_NA;
 518                         }
 519                         *data = g_variant_new_strv(s, i);
 520                         break;
 521                 default:
 522                         return SR_ERR_NA;
 523                 }
 524         } else {
 525                 /* Channel group specified. */
 526                 /*
 527                  * Per-channel-group options depending on a channel are actually
 528                  * done with the first channel. Channel groups in PPS can have
 529                  * more than one channel, but they will typically be of equal
 530                  * specification for use in series or parallel mode.
 531                  */
 532                 ch = cg->channels->data;
 533
 534                 switch (key) {
 535                 case SR_CONF_DEVICE_OPTIONS:
 536                         *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 537                                         devc->device->devopts_cg, devc->device->num_devopts_cg,
 538                                         sizeof(uint32_t));
 539                         break;
 540                 case SR_CONF_VOLTAGE_TARGET:
 541                         ch_spec = &(devc->device->channels[ch->index]);
 542                         g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
 543                         /* Min, max, write resolution. */
 544                         for (i = 0; i < 3; i++) {
 545                                 gvar = g_variant_new_double(ch_spec->voltage[i]);
 546                                 g_variant_builder_add_value(&gvb, gvar);
 547                         }
 548                         *data = g_variant_builder_end(&gvb);
 549                         break;
 550                 case SR_CONF_OUTPUT_FREQUENCY_TARGET:
 551                         ch_spec = &(devc->device->channels[ch->index]);
 552                         g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
 553                         /* Min, max, write resolution. */
 554                         for (i = 0; i < 3; i++) {
 555                                 gvar = g_variant_new_double(ch_spec->frequency[i]);
 556                                 g_variant_builder_add_value(&gvb, gvar);
 557                         }
 558                         *data = g_variant_builder_end(&gvb);
 559                         break;
 560                 case SR_CONF_CURRENT_LIMIT:
 561                         g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
 562                         /* Min, max, step. */
 563                         for (i = 0; i < 3; i++) {
 564                                 ch_spec = &(devc->device->channels[ch->index]);
 565                                 gvar = g_variant_new_double(ch_spec->current[i]);
 566                                 g_variant_builder_add_value(&gvb, gvar);
 567                         }
 568                         *data = g_variant_builder_end(&gvb);
 569                         break;
 570                 default:
 571                         return SR_ERR_NA;
 572                 }
 573         }
 574
 575         return ret;
 576 }
 577
 578 static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 579 {
 580         struct dev_context *devc;
 581         struct sr_scpi_dev_inst *scpi;
 582         struct sr_channel *ch;
 583         struct pps_channel *pch;
 584         int cmd, ret;
 585
 586         if (sdi->status != SR_ST_ACTIVE)
 587                 return SR_ERR_DEV_CLOSED;
 588
 589         devc = sdi->priv;
 590         scpi = sdi->conn;
 591
 592         if ((ret = sr_scpi_source_add(sdi->session, scpi, G_IO_IN, 10,
 593                         scpi_pps_receive_data, (void *)sdi)) != SR_OK)
 594                 return ret;
 595         std_session_send_df_header(sdi, LOG_PREFIX);
 596
 597         /* Prime the pipe with the first channel's fetch. */
 598         ch = sr_next_enabled_channel(sdi, NULL);
 599         pch = ch->priv;
 600         if ((ret = select_channel(sdi, ch)) < 0)
 601                 return ret;
 602         if (pch->mq == SR_MQ_VOLTAGE)
 603                 cmd = SCPI_CMD_GET_MEAS_VOLTAGE;
 604         else if (pch->mq == SR_MQ_FREQUENCY)
 605                 cmd = SCPI_CMD_GET_MEAS_FREQUENCY;
 606         else if (pch->mq == SR_MQ_CURRENT)
 607                 cmd = SCPI_CMD_GET_MEAS_CURRENT;
 608         else if (pch->mq == SR_MQ_POWER)
 609                 cmd = SCPI_CMD_GET_MEAS_POWER;
 610         else
 611                 return SR_ERR;
 612         scpi_cmd(sdi, devc->device->commands, cmd, pch->hwname);
 613
 614         return SR_OK;
 615 }
 616
 617 static int dev_acquisition_stop(struct sr_dev_inst *sdi)
 618 {
 619         struct sr_scpi_dev_inst *scpi;
 620         float f;
 621
 622         if (sdi->status != SR_ST_ACTIVE)
 623                 return SR_ERR_DEV_CLOSED;
 624
 625         scpi = sdi->conn;
 626
 627         /*
 628          * A requested value is certainly on the way. Retrieve it now,
 629          * to avoid leaving the device in a state where it's not expecting
 630          * commands.
 631          */
 632         sr_scpi_get_float(scpi, NULL, &f);
 633         sr_scpi_source_remove(sdi->session, scpi);
 634
 635         std_session_send_df_end(sdi, LOG_PREFIX);
 636
 637         return SR_OK;
 638 }
 639
 640 SR_PRIV struct sr_dev_driver scpi_pps_driver_info = {
 641         .name = "scpi-pps",
 642         .longname = "SCPI PPS",
 643         .api_version = 1,
 644         .init = init,
 645         .cleanup = cleanup,
 646         .scan = scan,
 647         .dev_list = dev_list,
 648         .dev_clear = dev_clear,
 649         .config_get = config_get,
 650         .config_set = config_set,
 651         .config_list = config_list,
 652         .dev_open = dev_open,
 653         .dev_close = dev_close,
 654         .dev_acquisition_start = dev_acquisition_start,
 655         .dev_acquisition_stop = dev_acquisition_stop,
 656         .context = NULL,
 657 };