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