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->status = SR_ST_INACTIVE;
  95         sdi->vendor = g_strdup(vendor);
  96         sdi->model = g_strdup(hw_info->model);
  97         sdi->version = g_strdup(hw_info->firmware_version);
  98         sdi->conn = scpi;
  99         sdi->driver = &scpi_pps_driver_info;
 100         sdi->inst_type = SR_INST_SCPI;
 101         sdi->serial_num = g_strdup(hw_info->serial_number);
 102
 103         devc = g_malloc0(sizeof(struct dev_context));
 104         devc->device = device;
 105         sdi->priv = devc;
 106
 107         if (device->num_channels) {
 108                 /* Static channels and groups. */
 109                 channels = (struct channel_spec *)device->channels;
 110                 num_channels = device->num_channels;
 111                 channel_groups = (struct channel_group_spec *)device->channel_groups;
 112                 num_channel_groups = device->num_channel_groups;
 113         } else {
 114                 /* Channels and groups need to be probed. */
 115                 ret = device->probe_channels(sdi, hw_info, &channels, &num_channels,
 116                                 &channel_groups, &num_channel_groups);
 117                 if (ret != SR_OK) {
 118                         sr_err("Failed to probe for channels.");
 119                         return NULL;
 120                 }
 121                 /*
 122                  * Since these were dynamically allocated, we'll need to free them
 123                  * later.
 124                  */
 125                 devc->channels = channels;
 126                 devc->channel_groups = channel_groups;
 127         }
 128
 129         ch_idx = 0;
 130         for (ch_num = 0; ch_num < num_channels; ch_num++) {
 131                 /* Create one channel per measurable output unit. */
 132                 for (i = 0; i < ARRAY_SIZE(pci); i++) {
 133                         if (!scpi_cmd_get(devc->device->commands, pci[i].command))
 134                                 continue;
 135                         g_snprintf(ch_name, 16, "%s%s", pci[i].prefix,
 136                                         channels[ch_num].name);
 137                         ch = sr_channel_new(sdi, ch_idx++, SR_CHANNEL_ANALOG, TRUE,
 138                                         ch_name);
 139                         pch = g_malloc0(sizeof(struct pps_channel));
 140                         pch->hw_output_idx = ch_num;
 141                         pch->hwname = channels[ch_num].name;
 142                         pch->mq = pci[i].mq;
 143                         ch->priv = pch;
 144                 }
 145         }
 146
 147         for (i = 0; i < num_channel_groups; i++) {
 148                 cgs = &channel_groups[i];
 149                 cg = g_malloc0(sizeof(struct sr_channel_group));
 150                 cg->name = g_strdup(cgs->name);
 151                 for (j = 0, mask = 1; j < 64; j++, mask <<= 1) {
 152                         if (cgs->channel_index_mask & mask) {
 153                                 for (l = sdi->channels; l; l = l->next) {
 154                                         ch = l->data;
 155                                         pch = ch->priv;
 156                                         if (pch->hw_output_idx == j)
 157                                                 cg->channels = g_slist_append(cg->channels, ch);
 158                                 }
 159                         }
 160                 }
 161                 pcg = g_malloc0(sizeof(struct pps_channel_group));
 162                 pcg->features = cgs->features;
 163                 cg->priv = pcg;
 164                 sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
 165         }
 166
 167         sr_scpi_hw_info_free(hw_info);
 168         hw_info = NULL;
 169
 170         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_LOCAL);
 171         sr_scpi_close(scpi);
 172
 173         return sdi;
 174 }
 175
 176 static GSList *scan(struct sr_dev_driver *di, GSList *options)
 177 {
 178         return sr_scpi_scan(di->context, options, probe_device);
 179 }
 180
 181 static GSList *dev_list(const struct sr_dev_driver *di)
 182 {
 183         return ((struct drv_context *)(di->context))->instances;
 184 }
 185
 186 static int dev_clear(const struct sr_dev_driver *di)
 187 {
 188         return std_dev_clear(di, NULL);
 189 }
 190
 191 static int dev_open(struct sr_dev_inst *sdi)
 192 {
 193         struct dev_context *devc;
 194         struct sr_scpi_dev_inst *scpi;
 195         GVariant *beeper;
 196
 197         if (sdi->status != SR_ST_INACTIVE)
 198                 return SR_ERR;
 199
 200         scpi = sdi->conn;
 201         if (sr_scpi_open(scpi) < 0)
 202                 return SR_ERR;
 203
 204         sdi->status = SR_ST_ACTIVE;
 205
 206         devc = sdi->priv;
 207         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_REMOTE);
 208         devc = sdi->priv;
 209         devc->beeper_was_set = FALSE;
 210         if (scpi_cmd_resp(sdi, devc->device->commands, &beeper,
 211                         G_VARIANT_TYPE_BOOLEAN, SCPI_CMD_BEEPER) == SR_OK) {
 212                 if (g_variant_get_boolean(beeper)) {
 213                         devc->beeper_was_set = TRUE;
 214                         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_BEEPER_DISABLE);
 215                 }
 216                 g_variant_unref(beeper);
 217         }
 218
 219         return SR_OK;
 220 }
 221
 222 static int dev_close(struct sr_dev_inst *sdi)
 223 {
 224         struct sr_scpi_dev_inst *scpi;
 225         struct dev_context *devc;
 226
 227         if (sdi->status != SR_ST_ACTIVE)
 228                 return SR_ERR_DEV_CLOSED;
 229
 230         devc = sdi->priv;
 231         scpi = sdi->conn;
 232         if (scpi) {
 233                 if (devc->beeper_was_set)
 234                         scpi_cmd(sdi, devc->device->commands, SCPI_CMD_BEEPER_ENABLE);
 235                 scpi_cmd(sdi, devc->device->commands, SCPI_CMD_LOCAL);
 236                 sr_scpi_close(scpi);
 237                 sdi->status = SR_ST_INACTIVE;
 238         }
 239
 240         return SR_OK;
 241 }
 242
 243 static void clear_helper(void *priv)
 244 {
 245         struct dev_context *devc;
 246
 247         devc = priv;
 248         g_free(devc->channels);
 249         g_free(devc->channel_groups);
 250         g_free(devc);
 251 }
 252
 253 static int cleanup(const struct sr_dev_driver *di)
 254 {
 255         return std_dev_clear(di, clear_helper);
 256 }
 257
 258 static int config_get(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
 259                 const struct sr_channel_group *cg)
 260 {
 261         struct dev_context *devc;
 262         const GVariantType *gvtype;
 263         unsigned int i;
 264         int cmd, ret;
 265         char *s;
 266
 267         if (!sdi)
 268                 return SR_ERR_ARG;
 269
 270         devc = sdi->priv;
 271
 272         if (cg) {
 273                 /*
 274                  * These options only apply to channel groups with a single
 275                  * channel -- they're per-channel settings for the device.
 276                  */
 277
 278                 /*
 279                  * Config keys are handled below depending on whether a channel
 280                  * group was provided by the frontend. However some of these
 281                  * take a CG on one PPS but not on others. Check the device's
 282                  * profile for that here, and NULL out the channel group as needed.
 283                  */
 284                 for (i = 0; i < devc->device->num_devopts; i++) {
 285                         if (devc->device->devopts[i] == key) {
 286                                 cg = NULL;
 287                                 break;
 288                         }
 289                 }
 290         }
 291
 292         gvtype = NULL;
 293         cmd = -1;
 294         switch (key) {
 295         case SR_CONF_ENABLED:
 296                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 297                 cmd = SCPI_CMD_GET_OUTPUT_ENABLED;
 298                 break;
 299         case SR_CONF_VOLTAGE:
 300                 gvtype = G_VARIANT_TYPE_DOUBLE;
 301                 cmd = SCPI_CMD_GET_MEAS_VOLTAGE;
 302                 break;
 303         case SR_CONF_VOLTAGE_TARGET:
 304                 gvtype = G_VARIANT_TYPE_DOUBLE;
 305                 cmd = SCPI_CMD_GET_VOLTAGE_TARGET;
 306                 break;
 307         case SR_CONF_OUTPUT_FREQUENCY:
 308                 gvtype = G_VARIANT_TYPE_DOUBLE;
 309                 cmd = SCPI_CMD_GET_MEAS_FREQUENCY;
 310                 break;
 311         case SR_CONF_OUTPUT_FREQUENCY_TARGET:
 312                 gvtype = G_VARIANT_TYPE_DOUBLE;
 313                 cmd = SCPI_CMD_GET_FREQUENCY_TARGET;
 314                 break;
 315         case SR_CONF_CURRENT:
 316                 gvtype = G_VARIANT_TYPE_DOUBLE;
 317                 cmd = SCPI_CMD_GET_MEAS_CURRENT;
 318                 break;
 319         case SR_CONF_CURRENT_LIMIT:
 320                 gvtype = G_VARIANT_TYPE_DOUBLE;
 321                 cmd = SCPI_CMD_GET_CURRENT_LIMIT;
 322                 break;
 323         case SR_CONF_OVER_VOLTAGE_PROTECTION_ENABLED:
 324                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 325                 cmd = SCPI_CMD_GET_OVER_VOLTAGE_PROTECTION_ENABLED;
 326                 break;
 327         case SR_CONF_OVER_VOLTAGE_PROTECTION_ACTIVE:
 328                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 329                 cmd = SCPI_CMD_GET_OVER_VOLTAGE_PROTECTION_ACTIVE;
 330                 break;
 331         case SR_CONF_OVER_VOLTAGE_PROTECTION_THRESHOLD:
 332                 gvtype = G_VARIANT_TYPE_DOUBLE;
 333                 cmd = SCPI_CMD_GET_OVER_VOLTAGE_PROTECTION_THRESHOLD;
 334                 break;
 335         case SR_CONF_OVER_CURRENT_PROTECTION_ENABLED:
 336                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 337                 cmd = SCPI_CMD_GET_OVER_CURRENT_PROTECTION_ENABLED;
 338                 break;
 339         case SR_CONF_OVER_CURRENT_PROTECTION_ACTIVE:
 340                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 341                 cmd = SCPI_CMD_GET_OVER_CURRENT_PROTECTION_ACTIVE;
 342                 break;
 343         case SR_CONF_OVER_CURRENT_PROTECTION_THRESHOLD:
 344                 gvtype = G_VARIANT_TYPE_DOUBLE;
 345                 cmd = SCPI_CMD_GET_OVER_CURRENT_PROTECTION_THRESHOLD;
 346                 break;
 347         case SR_CONF_OVER_TEMPERATURE_PROTECTION:
 348                 gvtype = G_VARIANT_TYPE_BOOLEAN;
 349                 cmd = SCPI_CMD_GET_OVER_TEMPERATURE_PROTECTION;
 350                 break;
 351         case SR_CONF_REGULATION:
 352                 gvtype = G_VARIANT_TYPE_STRING;
 353                 cmd = SCPI_CMD_GET_OUTPUT_REGULATION;
 354         }
 355         if (!gvtype)
 356                 return SR_ERR_NA;
 357
 358         if (cg)
 359                 select_channel(sdi, cg->channels->data);
 360         ret = scpi_cmd_resp(sdi, devc->device->commands, data, gvtype, cmd);
 361
 362         if (cmd == SCPI_CMD_GET_OUTPUT_REGULATION) {
 363                 /*
 364                  * The Rigol DP800 series return CV/CC/UR, Philips PM2800
 365                  * return VOLT/CURR. We always return a GVariant string in
 366                  * the Rigol notation.
 367                  */
 368                 if ((ret = sr_scpi_get_string(sdi->conn, NULL, &s)) != SR_OK)
 369                         return ret;
 370                 if (!strcmp(s, "CV") || !strcmp(s, "VOLT")) {
 371                         *data = g_variant_new_string("CV");
 372                 } else if (!strcmp(s, "CC") || !strcmp(s, "CURR")) {
 373                         *data = g_variant_new_string("CC");
 374                 } else if (!strcmp(s, "UR")) {
 375                         *data = g_variant_new_string("UR");
 376                 } else {
 377                         sr_dbg("Unknown response to SCPI_CMD_GET_OUTPUT_REGULATION: %s", s);
 378                         ret = SR_ERR_DATA;
 379                 }
 380                 g_free(s);
 381         }
 382
 383         return ret;
 384 }
 385
 386 static int config_set(uint32_t key, GVariant *data, const struct sr_dev_inst *sdi,
 387                 const struct sr_channel_group *cg)
 388 {
 389         struct dev_context *devc;
 390         double d;
 391         int ret;
 392
 393         if (!sdi)
 394                 return SR_ERR_ARG;
 395
 396         if (sdi->status != SR_ST_ACTIVE)
 397                 return SR_ERR_DEV_CLOSED;
 398
 399         if (cg)
 400                 /* Channel group specified. */
 401                 select_channel(sdi, cg->channels->data);
 402
 403         devc = sdi->priv;
 404         ret = SR_OK;
 405         switch (key) {
 406         case SR_CONF_ENABLED:
 407                 if (g_variant_get_boolean(data))
 408                         ret = scpi_cmd(sdi, devc->device->commands,
 409                                         SCPI_CMD_SET_OUTPUT_ENABLE);
 410                 else
 411                         ret = scpi_cmd(sdi, devc->device->commands,
 412                                         SCPI_CMD_SET_OUTPUT_DISABLE);
 413                 break;
 414         case SR_CONF_VOLTAGE_TARGET:
 415                 d = g_variant_get_double(data);
 416                 ret = scpi_cmd(sdi, devc->device->commands,
 417                                 SCPI_CMD_SET_VOLTAGE_TARGET, d);
 418                 break;
 419         case SR_CONF_OUTPUT_FREQUENCY_TARGET:
 420                 d = g_variant_get_double(data);
 421                 ret = scpi_cmd(sdi, devc->device->commands,
 422                                 SCPI_CMD_SET_FREQUENCY_TARGET, d);
 423                 break;
 424         case SR_CONF_CURRENT_LIMIT:
 425                 d = g_variant_get_double(data);
 426                 ret = scpi_cmd(sdi, devc->device->commands,
 427                                 SCPI_CMD_SET_CURRENT_LIMIT, d);
 428                 break;
 429         case SR_CONF_OVER_VOLTAGE_PROTECTION_ENABLED:
 430                 if (g_variant_get_boolean(data))
 431                         ret = scpi_cmd(sdi, devc->device->commands,
 432                                         SCPI_CMD_SET_OVER_VOLTAGE_PROTECTION_ENABLE);
 433                 else
 434                         ret = scpi_cmd(sdi, devc->device->commands,
 435                                         SCPI_CMD_SET_OVER_VOLTAGE_PROTECTION_DISABLE);
 436                 break;
 437         case SR_CONF_OVER_VOLTAGE_PROTECTION_THRESHOLD:
 438                 d = g_variant_get_double(data);
 439                 ret = scpi_cmd(sdi, devc->device->commands,
 440                                 SCPI_CMD_SET_OVER_VOLTAGE_PROTECTION_THRESHOLD, d);
 441                 break;
 442         case SR_CONF_OVER_CURRENT_PROTECTION_ENABLED:
 443                 if (g_variant_get_boolean(data))
 444                         ret = scpi_cmd(sdi, devc->device->commands,
 445                                         SCPI_CMD_SET_OVER_CURRENT_PROTECTION_ENABLE);
 446                 else
 447                         ret = scpi_cmd(sdi, devc->device->commands,
 448                                         SCPI_CMD_SET_OVER_CURRENT_PROTECTION_DISABLE);
 449                 break;
 450         case SR_CONF_OVER_CURRENT_PROTECTION_THRESHOLD:
 451                 d = g_variant_get_double(data);
 452                 ret = scpi_cmd(sdi, devc->device->commands,
 453                                 SCPI_CMD_SET_OVER_CURRENT_PROTECTION_THRESHOLD, d);
 454                 break;
 455         case SR_CONF_OVER_TEMPERATURE_PROTECTION:
 456                 if (g_variant_get_boolean(data))
 457                         ret = scpi_cmd(sdi, devc->device->commands,
 458                                         SCPI_CMD_SET_OVER_TEMPERATURE_PROTECTION_ENABLE);
 459                 else
 460                         ret = scpi_cmd(sdi, devc->device->commands,
 461                                         SCPI_CMD_SET_OVER_TEMPERATURE_PROTECTION_DISABLE);
 462                 break;
 463         default:
 464                 ret = SR_ERR_NA;
 465         }
 466
 467         return ret;
 468 }
 469
 470 static int config_list(uint32_t key, GVariant **data, const struct sr_dev_inst *sdi,
 471                 const struct sr_channel_group *cg)
 472 {
 473         struct dev_context *devc;
 474         struct sr_channel *ch;
 475         const struct channel_spec *ch_spec;
 476         GVariant *gvar;
 477         GVariantBuilder gvb;
 478         int ret, i;
 479         const char *s[16];
 480
 481         /* Always available, even without sdi. */
 482         if (key == SR_CONF_SCAN_OPTIONS) {
 483                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 484                                 scanopts, ARRAY_SIZE(scanopts), sizeof(uint32_t));
 485                 return SR_OK;
 486         } else if (key == SR_CONF_DEVICE_OPTIONS && !sdi) {
 487                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 488                                 drvopts, ARRAY_SIZE(drvopts), sizeof(uint32_t));
 489                 return SR_OK;
 490         }
 491
 492         if (!sdi)
 493                 return SR_ERR_ARG;
 494         devc = sdi->priv;
 495
 496         ret = SR_OK;
 497         if (!cg) {
 498                 /* No channel group: global options. */
 499                 switch (key) {
 500                 case SR_CONF_DEVICE_OPTIONS:
 501                         *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 502                                         devc->device->devopts, devc->device->num_devopts,
 503                                         sizeof(uint32_t));
 504                         break;
 505                 case SR_CONF_CHANNEL_CONFIG:
 506                         /* Not used. */
 507                         i = 0;
 508                         if (devc->device->features & PPS_INDEPENDENT)
 509                                 s[i++] = "Independent";
 510                         if (devc->device->features & PPS_SERIES)
 511                                 s[i++] = "Series";
 512                         if (devc->device->features & PPS_PARALLEL)
 513                                 s[i++] = "Parallel";
 514                         if (i == 0) {
 515                                 /*
 516                                  * Shouldn't happen: independent-only devices
 517                                  * shouldn't advertise this option at all.
 518                                  */
 519                                 return SR_ERR_NA;
 520                         }
 521                         *data = g_variant_new_strv(s, i);
 522                         break;
 523                 default:
 524                         return SR_ERR_NA;
 525                 }
 526         } else {
 527                 /* Channel group specified. */
 528                 /*
 529                  * Per-channel-group options depending on a channel are actually
 530                  * done with the first channel. Channel groups in PPS can have
 531                  * more than one channel, but they will typically be of equal
 532                  * specification for use in series or parallel mode.
 533                  */
 534                 ch = cg->channels->data;
 535
 536                 switch (key) {
 537                 case SR_CONF_DEVICE_OPTIONS:
 538                         *data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
 539                                         devc->device->devopts_cg, devc->device->num_devopts_cg,
 540                                         sizeof(uint32_t));
 541                         break;
 542                 case SR_CONF_VOLTAGE_TARGET:
 543                         ch_spec = &(devc->device->channels[ch->index]);
 544                         g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
 545                         /* Min, max, write resolution. */
 546                         for (i = 0; i < 3; i++) {
 547                                 gvar = g_variant_new_double(ch_spec->voltage[i]);
 548                                 g_variant_builder_add_value(&gvb, gvar);
 549                         }
 550                         *data = g_variant_builder_end(&gvb);
 551                         break;
 552                 case SR_CONF_OUTPUT_FREQUENCY_TARGET:
 553                         ch_spec = &(devc->device->channels[ch->index]);
 554                         g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
 555                         /* Min, max, write resolution. */
 556                         for (i = 0; i < 3; i++) {
 557                                 gvar = g_variant_new_double(ch_spec->frequency[i]);
 558                                 g_variant_builder_add_value(&gvb, gvar);
 559                         }
 560                         *data = g_variant_builder_end(&gvb);
 561                         break;
 562                 case SR_CONF_CURRENT_LIMIT:
 563                         g_variant_builder_init(&gvb, G_VARIANT_TYPE_ARRAY);
 564                         /* Min, max, step. */
 565                         for (i = 0; i < 3; i++) {
 566                                 ch_spec = &(devc->device->channels[ch->index]);
 567                                 gvar = g_variant_new_double(ch_spec->current[i]);
 568                                 g_variant_builder_add_value(&gvb, gvar);
 569                         }
 570                         *data = g_variant_builder_end(&gvb);
 571                         break;
 572                 default:
 573                         return SR_ERR_NA;
 574                 }
 575         }
 576
 577         return ret;
 578 }
 579
 580 static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
 581 {
 582         struct dev_context *devc;
 583         struct sr_scpi_dev_inst *scpi;
 584         struct sr_channel *ch;
 585         struct pps_channel *pch;
 586         int cmd, ret;
 587
 588         if (sdi->status != SR_ST_ACTIVE)
 589                 return SR_ERR_DEV_CLOSED;
 590
 591         devc = sdi->priv;
 592         scpi = sdi->conn;
 593         devc->cb_data = cb_data;
 594
 595         if ((ret = sr_scpi_source_add(sdi->session, scpi, G_IO_IN, 10,
 596                         scpi_pps_receive_data, (void *)sdi)) != SR_OK)
 597                 return ret;
 598         std_session_send_df_header(sdi, LOG_PREFIX);
 599
 600         /* Prime the pipe with the first channel's fetch. */
 601         ch = sr_next_enabled_channel(sdi, NULL);
 602         pch = ch->priv;
 603         if ((ret = select_channel(sdi, ch)) < 0)
 604                 return ret;
 605         if (pch->mq == SR_MQ_VOLTAGE)
 606                 cmd = SCPI_CMD_GET_MEAS_VOLTAGE;
 607         else if (pch->mq == SR_MQ_FREQUENCY)
 608                 cmd = SCPI_CMD_GET_MEAS_FREQUENCY;
 609         else if (pch->mq == SR_MQ_CURRENT)
 610                 cmd = SCPI_CMD_GET_MEAS_CURRENT;
 611         else if (pch->mq == SR_MQ_POWER)
 612                 cmd = SCPI_CMD_GET_MEAS_POWER;
 613         else
 614                 return SR_ERR;
 615         scpi_cmd(sdi, devc->device->commands, cmd, pch->hwname);
 616
 617         return SR_OK;
 618 }
 619
 620 static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 621 {
 622         struct sr_datafeed_packet packet;
 623         struct sr_scpi_dev_inst *scpi;
 624         float f;
 625
 626         (void)cb_data;
 627
 628         if (sdi->status != SR_ST_ACTIVE)
 629                 return SR_ERR_DEV_CLOSED;
 630
 631         scpi = sdi->conn;
 632
 633         /*
 634          * A requested value is certainly on the way. Retrieve it now,
 635          * to avoid leaving the device in a state where it's not expecting
 636          * commands.
 637          */
 638         sr_scpi_get_float(scpi, NULL, &f);
 639         sr_scpi_source_remove(sdi->session, scpi);
 640
 641         packet.type = SR_DF_END;
 642         sr_session_send(sdi, &packet);
 643
 644         return SR_OK;
 645 }
 646
 647 SR_PRIV struct sr_dev_driver scpi_pps_driver_info = {
 648         .name = "scpi-pps",
 649         .longname = "SCPI PPS",
 650         .api_version = 1,
 651         .init = init,
 652         .cleanup = cleanup,
 653         .scan = scan,
 654         .dev_list = dev_list,
 655         .dev_clear = dev_clear,
 656         .config_get = config_get,
 657         .config_set = config_set,
 658         .config_list = config_list,
 659         .dev_open = dev_open,
 660         .dev_close = dev_close,
 661         .dev_acquisition_start = dev_acquisition_start,
 662         .dev_acquisition_stop = dev_acquisition_stop,
 663         .context = NULL,
 664 };