src/hardware/fx2lafw/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
   5  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <glib.h>
  23 #include <glib/gstdio.h>
  24 #include "protocol.h"
  25
  26 #pragma pack(push, 1)
  27
  28 struct version_info {
  29         uint8_t major;
  30         uint8_t minor;
  31 };
  32
  33 struct cmd_start_acquisition {
  34         uint8_t flags;
  35         uint8_t sample_delay_h;
  36         uint8_t sample_delay_l;
  37 };
  38
  39 #pragma pack(pop)
  40
  41 #define USB_TIMEOUT 100
  42
  43 static int command_get_fw_version(libusb_device_handle *devhdl,
  44                                   struct version_info *vi)
  45 {
  46         int ret;
  47
  48         ret = libusb_control_transfer(devhdl, LIBUSB_REQUEST_TYPE_VENDOR |
  49                 LIBUSB_ENDPOINT_IN, CMD_GET_FW_VERSION, 0x0000, 0x0000,
  50                 (unsigned char *)vi, sizeof(struct version_info), USB_TIMEOUT);
  51
  52         if (ret < 0) {
  53                 sr_err("Unable to get version info: %s.",
  54                        libusb_error_name(ret));
  55                 return SR_ERR;
  56         }
  57
  58         return SR_OK;
  59 }
  60
  61 static int command_get_revid_version(struct sr_dev_inst *sdi, uint8_t *revid)
  62 {
  63         struct sr_usb_dev_inst *usb = sdi->conn;
  64         libusb_device_handle *devhdl = usb->devhdl;
  65         int ret;
  66
  67         ret = libusb_control_transfer(devhdl, LIBUSB_REQUEST_TYPE_VENDOR |
  68                 LIBUSB_ENDPOINT_IN, CMD_GET_REVID_VERSION, 0x0000, 0x0000,
  69                 revid, 1, USB_TIMEOUT);
  70
  71         if (ret < 0) {
  72                 sr_err("Unable to get REVID: %s.", libusb_error_name(ret));
  73                 return SR_ERR;
  74         }
  75
  76         return SR_OK;
  77 }
  78
  79 static int command_start_acquisition(const struct sr_dev_inst *sdi)
  80 {
  81         struct dev_context *devc;
  82         struct sr_usb_dev_inst *usb;
  83         uint64_t samplerate;
  84         struct cmd_start_acquisition cmd;
  85         int delay, ret;
  86
  87         devc = sdi->priv;
  88         usb = sdi->conn;
  89         samplerate = devc->cur_samplerate;
  90
  91         /* Compute the sample rate. */
  92         if (devc->sample_wide && samplerate > MAX_16BIT_SAMPLE_RATE) {
  93                 sr_err("Unable to sample at %" PRIu64 "Hz "
  94                        "when collecting 16-bit samples.", samplerate);
  95                 return SR_ERR;
  96         }
  97
  98         delay = 0;
  99         cmd.flags = cmd.sample_delay_h = cmd.sample_delay_l = 0;
 100         if ((SR_MHZ(48) % samplerate) == 0) {
 101                 cmd.flags = CMD_START_FLAGS_CLK_48MHZ;
 102                 delay = SR_MHZ(48) / samplerate - 1;
 103                 if (delay > MAX_SAMPLE_DELAY)
 104                         delay = 0;
 105         }
 106
 107         if (delay == 0 && (SR_MHZ(30) % samplerate) == 0) {
 108                 cmd.flags = CMD_START_FLAGS_CLK_30MHZ;
 109                 delay = SR_MHZ(30) / samplerate - 1;
 110         }
 111
 112         sr_dbg("GPIF delay = %d, clocksource = %sMHz.", delay,
 113                 (cmd.flags & CMD_START_FLAGS_CLK_48MHZ) ? "48" : "30");
 114
 115         if (delay <= 0 || delay > MAX_SAMPLE_DELAY) {
 116                 sr_err("Unable to sample at %" PRIu64 "Hz.", samplerate);
 117                 return SR_ERR;
 118         }
 119
 120         cmd.sample_delay_h = (delay >> 8) & 0xff;
 121         cmd.sample_delay_l = delay & 0xff;
 122
 123         /* Select the sampling width. */
 124         cmd.flags |= devc->sample_wide ? CMD_START_FLAGS_SAMPLE_16BIT :
 125                 CMD_START_FLAGS_SAMPLE_8BIT;
 126         /* Enable CTL2 clock. */
 127         cmd.flags |= (g_slist_length(devc->enabled_analog_channels) > 0) ? CMD_START_FLAGS_CLK_CTL2 : 0;
 128
 129         /* Send the control message. */
 130         ret = libusb_control_transfer(usb->devhdl, LIBUSB_REQUEST_TYPE_VENDOR |
 131                         LIBUSB_ENDPOINT_OUT, CMD_START, 0x0000, 0x0000,
 132                         (unsigned char *)&cmd, sizeof(cmd), USB_TIMEOUT);
 133         if (ret < 0) {
 134                 sr_err("Unable to send start command: %s.",
 135                        libusb_error_name(ret));
 136                 return SR_ERR;
 137         }
 138
 139         return SR_OK;
 140 }
 141
 142 SR_PRIV int fx2lafw_dev_open(struct sr_dev_inst *sdi, struct sr_dev_driver *di)
 143 {
 144         libusb_device **devlist;
 145         struct sr_usb_dev_inst *usb;
 146         struct libusb_device_descriptor des;
 147         struct dev_context *devc;
 148         struct drv_context *drvc;
 149         struct version_info vi;
 150         int ret = SR_ERR, i, device_count;
 151         uint8_t revid;
 152         char connection_id[64];
 153
 154         drvc = di->context;
 155         devc = sdi->priv;
 156         usb = sdi->conn;
 157
 158         device_count = libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
 159         if (device_count < 0) {
 160                 sr_err("Failed to get device list: %s.",
 161                        libusb_error_name(device_count));
 162                 return SR_ERR;
 163         }
 164
 165         for (i = 0; i < device_count; i++) {
 166                 libusb_get_device_descriptor(devlist[i], &des);
 167
 168                 if (des.idVendor != devc->profile->vid
 169                     || des.idProduct != devc->profile->pid)
 170                         continue;
 171
 172                 if ((sdi->status == SR_ST_INITIALIZING) ||
 173                                 (sdi->status == SR_ST_INACTIVE)) {
 174                         /*
 175                          * Check device by its physical USB bus/port address.
 176                          */
 177                         usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
 178                         if (strcmp(sdi->connection_id, connection_id))
 179                                 /* This is not the one. */
 180                                 continue;
 181                 }
 182
 183                 if (!(ret = libusb_open(devlist[i], &usb->devhdl))) {
 184                         if (usb->address == 0xff)
 185                                 /*
 186                                  * First time we touch this device after FW
 187                                  * upload, so we don't know the address yet.
 188                                  */
 189                                 usb->address = libusb_get_device_address(devlist[i]);
 190                 } else {
 191                         sr_err("Failed to open device: %s.",
 192                                libusb_error_name(ret));
 193                         ret = SR_ERR;
 194                         break;
 195                 }
 196
 197                 if (libusb_has_capability(LIBUSB_CAP_SUPPORTS_DETACH_KERNEL_DRIVER)) {
 198                         if (libusb_kernel_driver_active(usb->devhdl, USB_INTERFACE) == 1) {
 199                                 if ((ret = libusb_detach_kernel_driver(usb->devhdl, USB_INTERFACE)) < 0) {
 200                                         sr_err("Failed to detach kernel driver: %s.",
 201                                                 libusb_error_name(ret));
 202                                         ret = SR_ERR;
 203                                         break;
 204                                 }
 205                         }
 206                 }
 207
 208                 ret = command_get_fw_version(usb->devhdl, &vi);
 209                 if (ret != SR_OK) {
 210                         sr_err("Failed to get firmware version.");
 211                         break;
 212                 }
 213
 214                 ret = command_get_revid_version(sdi, &revid);
 215                 if (ret != SR_OK) {
 216                         sr_err("Failed to get REVID.");
 217                         break;
 218                 }
 219
 220                 /*
 221                  * Changes in major version mean incompatible/API changes, so
 222                  * bail out if we encounter an incompatible version.
 223                  * Different minor versions are OK, they should be compatible.
 224                  */
 225                 if (vi.major != FX2LAFW_REQUIRED_VERSION_MAJOR) {
 226                         sr_err("Expected firmware version %d.x, "
 227                                "got %d.%d.", FX2LAFW_REQUIRED_VERSION_MAJOR,
 228                                vi.major, vi.minor);
 229                         break;
 230                 }
 231
 232                 sr_info("Opened device on %d.%d (logical) / %s (physical), "
 233                         "interface %d, firmware %d.%d.",
 234                         usb->bus, usb->address, connection_id,
 235                         USB_INTERFACE, vi.major, vi.minor);
 236
 237                 sr_info("Detected REVID=%d, it's a Cypress CY7C68013%s.",
 238                         revid, (revid != 1) ? " (FX2)" : "A (FX2LP)");
 239
 240                 ret = SR_OK;
 241
 242                 break;
 243         }
 244
 245         libusb_free_device_list(devlist, 1);
 246
 247         return ret;
 248 }
 249
 250 SR_PRIV struct dev_context *fx2lafw_dev_new(void)
 251 {
 252         struct dev_context *devc;
 253
 254         devc = g_malloc0(sizeof(struct dev_context));
 255         devc->profile = NULL;
 256         devc->fw_updated = 0;
 257         devc->cur_samplerate = 0;
 258         devc->limit_samples = 0;
 259         devc->capture_ratio = 0;
 260         devc->sample_wide = FALSE;
 261         devc->stl = NULL;
 262
 263         return devc;
 264 }
 265
 266 SR_PRIV void fx2lafw_abort_acquisition(struct dev_context *devc)
 267 {
 268         int i;
 269
 270         devc->acq_aborted = TRUE;
 271
 272         for (i = devc->num_transfers - 1; i >= 0; i--) {
 273                 if (devc->transfers[i])
 274                         libusb_cancel_transfer(devc->transfers[i]);
 275         }
 276 }
 277
 278 static void finish_acquisition(struct sr_dev_inst *sdi)
 279 {
 280         struct dev_context *devc;
 281
 282         devc = sdi->priv;
 283
 284         std_session_send_df_end(sdi);
 285
 286         usb_source_remove(sdi->session, devc->ctx);
 287
 288         devc->num_transfers = 0;
 289         g_free(devc->transfers);
 290
 291         /* Free the deinterlace buffers if we had them. */
 292         if (g_slist_length(devc->enabled_analog_channels) > 0) {
 293                 g_free(devc->logic_buffer);
 294                 g_free(devc->analog_buffer);
 295         }
 296
 297         if (devc->stl) {
 298                 soft_trigger_logic_free(devc->stl);
 299                 devc->stl = NULL;
 300         }
 301 }
 302
 303 static void free_transfer(struct libusb_transfer *transfer)
 304 {
 305         struct sr_dev_inst *sdi;
 306         struct dev_context *devc;
 307         unsigned int i;
 308
 309         sdi = transfer->user_data;
 310         devc = sdi->priv;
 311
 312         g_free(transfer->buffer);
 313         transfer->buffer = NULL;
 314         libusb_free_transfer(transfer);
 315
 316         for (i = 0; i < devc->num_transfers; i++) {
 317                 if (devc->transfers[i] == transfer) {
 318                         devc->transfers[i] = NULL;
 319                         break;
 320                 }
 321         }
 322
 323         devc->submitted_transfers--;
 324         if (devc->submitted_transfers == 0)
 325                 finish_acquisition(sdi);
 326 }
 327
 328 static void resubmit_transfer(struct libusb_transfer *transfer)
 329 {
 330         int ret;
 331
 332         if ((ret = libusb_submit_transfer(transfer)) == LIBUSB_SUCCESS)
 333                 return;
 334
 335         sr_err("%s: %s", __func__, libusb_error_name(ret));
 336         free_transfer(transfer);
 337
 338 }
 339
 340 static void mso_send_data_proc(struct sr_dev_inst *sdi,
 341         uint8_t *data, size_t length, size_t sample_width)
 342 {
 343         size_t i;
 344         struct dev_context *devc;
 345         struct sr_datafeed_analog analog;
 346         struct sr_analog_encoding encoding;
 347         struct sr_analog_meaning meaning;
 348         struct sr_analog_spec spec;
 349
 350         (void)sample_width;
 351
 352         devc = sdi->priv;
 353
 354         length /= 2;
 355
 356         /* Send the logic */
 357         for (i = 0; i < length; i++) {
 358                 devc->logic_buffer[i] = data[i * 2];
 359                 /* Rescale to -10V - +10V from 0-255. */
 360                 devc->analog_buffer[i] = (data[i * 2 + 1] - 128.0f) / 12.8f;
 361         };
 362
 363         const struct sr_datafeed_logic logic = {
 364                 .length = length,
 365                 .unitsize = 1,
 366                 .data = devc->logic_buffer
 367         };
 368
 369         const struct sr_datafeed_packet logic_packet = {
 370                 .type = SR_DF_LOGIC,
 371                 .payload = &logic
 372         };
 373
 374         sr_session_send(sdi, &logic_packet);
 375
 376         sr_analog_init(&analog, &encoding, &meaning, &spec, 2);
 377         analog.meaning->channels = devc->enabled_analog_channels;
 378         analog.meaning->mq = SR_MQ_VOLTAGE;
 379         analog.meaning->unit = SR_UNIT_VOLT;
 380         analog.meaning->mqflags = 0 /* SR_MQFLAG_DC */;
 381         analog.num_samples = length;
 382         analog.data = devc->analog_buffer;
 383
 384         const struct sr_datafeed_packet analog_packet = {
 385                 .type = SR_DF_ANALOG,
 386                 .payload = &analog
 387         };
 388
 389         sr_session_send(sdi, &analog_packet);
 390 }
 391
 392 static void la_send_data_proc(struct sr_dev_inst *sdi,
 393         uint8_t *data, size_t length, size_t sample_width)
 394 {
 395         const struct sr_datafeed_logic logic = {
 396                 .length = length,
 397                 .unitsize = sample_width,
 398                 .data = data
 399         };
 400
 401         const struct sr_datafeed_packet packet = {
 402                 .type = SR_DF_LOGIC,
 403                 .payload = &logic
 404         };
 405
 406         sr_session_send(sdi, &packet);
 407 }
 408
 409 static void LIBUSB_CALL receive_transfer(struct libusb_transfer *transfer)
 410 {
 411         struct sr_dev_inst *sdi;
 412         struct dev_context *devc;
 413         gboolean packet_has_error = FALSE;
 414         unsigned int num_samples;
 415         int trigger_offset, cur_sample_count, unitsize;
 416         int pre_trigger_samples;
 417
 418         sdi = transfer->user_data;
 419         devc = sdi->priv;
 420
 421         /*
 422          * If acquisition has already ended, just free any queued up
 423          * transfer that come in.
 424          */
 425         if (devc->acq_aborted) {
 426                 free_transfer(transfer);
 427                 return;
 428         }
 429
 430         sr_dbg("receive_transfer(): status %s received %d bytes.",
 431                 libusb_error_name(transfer->status), transfer->actual_length);
 432
 433         /* Save incoming transfer before reusing the transfer struct. */
 434         unitsize = devc->sample_wide ? 2 : 1;
 435         cur_sample_count = transfer->actual_length / unitsize;
 436
 437         switch (transfer->status) {
 438         case LIBUSB_TRANSFER_NO_DEVICE:
 439                 fx2lafw_abort_acquisition(devc);
 440                 free_transfer(transfer);
 441                 return;
 442         case LIBUSB_TRANSFER_COMPLETED:
 443         case LIBUSB_TRANSFER_TIMED_OUT: /* We may have received some data though. */
 444                 break;
 445         default:
 446                 packet_has_error = TRUE;
 447                 break;
 448         }
 449
 450         if (transfer->actual_length == 0 || packet_has_error) {
 451                 devc->empty_transfer_count++;
 452                 if (devc->empty_transfer_count > MAX_EMPTY_TRANSFERS) {
 453                         /*
 454                          * The FX2 gave up. End the acquisition, the frontend
 455                          * will work out that the samplecount is short.
 456                          */
 457                         fx2lafw_abort_acquisition(devc);
 458                         free_transfer(transfer);
 459                 } else {
 460                         resubmit_transfer(transfer);
 461                 }
 462                 return;
 463         } else {
 464                 devc->empty_transfer_count = 0;
 465         }
 466         if (devc->trigger_fired) {
 467                 if (!devc->limit_samples || devc->sent_samples < devc->limit_samples) {
 468                         /* Send the incoming transfer to the session bus. */
 469                         if (devc->limit_samples && devc->sent_samples + cur_sample_count > devc->limit_samples)
 470                                 num_samples = devc->limit_samples - devc->sent_samples;
 471                         else
 472                                 num_samples = cur_sample_count;
 473
 474                         devc->send_data_proc(sdi, (uint8_t *)transfer->buffer,
 475                                 num_samples * unitsize, unitsize);
 476                         devc->sent_samples += num_samples;
 477                 }
 478         } else {
 479                 trigger_offset = soft_trigger_logic_check(devc->stl,
 480                         transfer->buffer, transfer->actual_length, &pre_trigger_samples);
 481                 if (trigger_offset > -1) {
 482                         devc->sent_samples += pre_trigger_samples;
 483                         num_samples = cur_sample_count - trigger_offset;
 484                         if (devc->limit_samples &&
 485                                         num_samples > devc->limit_samples - devc->sent_samples)
 486                                 num_samples = devc->limit_samples - devc->sent_samples;
 487
 488                         devc->send_data_proc(sdi, (uint8_t *)transfer->buffer
 489                                         + trigger_offset * unitsize,
 490                                         num_samples * unitsize, unitsize);
 491                         devc->sent_samples += num_samples;
 492
 493                         devc->trigger_fired = TRUE;
 494                 }
 495         }
 496
 497         if (devc->limit_samples && devc->sent_samples >= devc->limit_samples) {
 498                 fx2lafw_abort_acquisition(devc);
 499                 free_transfer(transfer);
 500         } else
 501                 resubmit_transfer(transfer);
 502 }
 503
 504 static int configure_channels(const struct sr_dev_inst *sdi)
 505 {
 506         struct dev_context *devc;
 507         const GSList *l;
 508         int p;
 509         struct sr_channel *ch;
 510         uint32_t channel_mask = 0, num_analog = 0;
 511
 512         devc = sdi->priv;
 513
 514         g_slist_free(devc->enabled_analog_channels);
 515         devc->enabled_analog_channels = NULL;
 516
 517         for (l = sdi->channels, p = 0; l; l = l->next, p++) {
 518                 ch = l->data;
 519                 if ((p <= NUM_CHANNELS) && (ch->type == SR_CHANNEL_ANALOG)
 520                                 && (ch->enabled)) {
 521                         num_analog++;
 522                         devc->enabled_analog_channels =
 523                             g_slist_append(devc->enabled_analog_channels, ch);
 524                 } else {
 525                         channel_mask |= ch->enabled << p;
 526                 }
 527         }
 528
 529         /*
 530          * Use wide sampling if either any of the LA channels 8..15 is enabled,
 531          * and/or at least one analog channel is enabled.
 532          */
 533         devc->sample_wide = channel_mask > 0xff || num_analog > 0;
 534
 535         return SR_OK;
 536 }
 537
 538 static unsigned int to_bytes_per_ms(unsigned int samplerate)
 539 {
 540         return samplerate / 1000;
 541 }
 542
 543 static size_t get_buffer_size(struct dev_context *devc)
 544 {
 545         size_t s;
 546
 547         /*
 548          * The buffer should be large enough to hold 10ms of data and
 549          * a multiple of 512.
 550          */
 551         s = 10 * to_bytes_per_ms(devc->cur_samplerate);
 552         return (s + 511) & ~511;
 553 }
 554
 555 static unsigned int get_number_of_transfers(struct dev_context *devc)
 556 {
 557         unsigned int n;
 558
 559         /* Total buffer size should be able to hold about 500ms of data. */
 560         n = (500 * to_bytes_per_ms(devc->cur_samplerate) /
 561                 get_buffer_size(devc));
 562
 563         if (n > NUM_SIMUL_TRANSFERS)
 564                 return NUM_SIMUL_TRANSFERS;
 565
 566         return n;
 567 }
 568
 569 static unsigned int get_timeout(struct dev_context *devc)
 570 {
 571         size_t total_size;
 572         unsigned int timeout;
 573
 574         total_size = get_buffer_size(devc) *
 575                         get_number_of_transfers(devc);
 576         timeout = total_size / to_bytes_per_ms(devc->cur_samplerate);
 577         return timeout + timeout / 4; /* Leave a headroom of 25% percent. */
 578 }
 579
 580 static int receive_data(int fd, int revents, void *cb_data)
 581 {
 582         struct timeval tv;
 583         struct drv_context *drvc;
 584
 585         (void)fd;
 586         (void)revents;
 587
 588         drvc = (struct drv_context *)cb_data;
 589
 590         tv.tv_sec = tv.tv_usec = 0;
 591         libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
 592
 593         return TRUE;
 594 }
 595
 596 static int start_transfers(const struct sr_dev_inst *sdi)
 597 {
 598         struct dev_context *devc;
 599         struct sr_usb_dev_inst *usb;
 600         struct sr_trigger *trigger;
 601         struct libusb_transfer *transfer;
 602         unsigned int i, num_transfers;
 603         int timeout, ret;
 604         unsigned char *buf;
 605         size_t size;
 606
 607         devc = sdi->priv;
 608         usb = sdi->conn;
 609
 610         devc->sent_samples = 0;
 611         devc->acq_aborted = FALSE;
 612         devc->empty_transfer_count = 0;
 613
 614         if ((trigger = sr_session_trigger_get(sdi->session))) {
 615                 int pre_trigger_samples = 0;
 616                 if (devc->limit_samples > 0)
 617                         pre_trigger_samples = devc->capture_ratio * devc->limit_samples/100;
 618                 devc->stl = soft_trigger_logic_new(sdi, trigger, pre_trigger_samples);
 619                 if (!devc->stl)
 620                         return SR_ERR_MALLOC;
 621                 devc->trigger_fired = FALSE;
 622         } else
 623                 devc->trigger_fired = TRUE;
 624
 625         num_transfers = get_number_of_transfers(devc);
 626
 627         size = get_buffer_size(devc);
 628         devc->submitted_transfers = 0;
 629
 630         devc->transfers = g_try_malloc0(sizeof(*devc->transfers) * num_transfers);
 631         if (!devc->transfers) {
 632                 sr_err("USB transfers malloc failed.");
 633                 return SR_ERR_MALLOC;
 634         }
 635
 636         timeout = get_timeout(devc);
 637         devc->num_transfers = num_transfers;
 638         for (i = 0; i < num_transfers; i++) {
 639                 if (!(buf = g_try_malloc(size))) {
 640                         sr_err("USB transfer buffer malloc failed.");
 641                         return SR_ERR_MALLOC;
 642                 }
 643                 transfer = libusb_alloc_transfer(0);
 644                 libusb_fill_bulk_transfer(transfer, usb->devhdl,
 645                                 2 | LIBUSB_ENDPOINT_IN, buf, size,
 646                                 receive_transfer, (void *)sdi, timeout);
 647                 sr_info("submitting transfer: %d", i);
 648                 if ((ret = libusb_submit_transfer(transfer)) != 0) {
 649                         sr_err("Failed to submit transfer: %s.",
 650                                libusb_error_name(ret));
 651                         libusb_free_transfer(transfer);
 652                         g_free(buf);
 653                         fx2lafw_abort_acquisition(devc);
 654                         return SR_ERR;
 655                 }
 656                 devc->transfers[i] = transfer;
 657                 devc->submitted_transfers++;
 658         }
 659
 660         /*
 661          * If this device has analog channels and at least one of them is
 662          * enabled, use mso_send_data_proc() to properly handle the analog
 663          * data. Otherwise use la_send_data_proc().
 664          */
 665         if (g_slist_length(devc->enabled_analog_channels) > 0)
 666                 devc->send_data_proc = mso_send_data_proc;
 667         else
 668                 devc->send_data_proc = la_send_data_proc;
 669
 670         std_session_send_df_header(sdi);
 671
 672         return SR_OK;
 673 }
 674
 675 SR_PRIV int fx2lafw_start_acquisition(const struct sr_dev_inst *sdi)
 676 {
 677         struct sr_dev_driver *di;
 678         struct drv_context *drvc;
 679         struct dev_context *devc;
 680         int timeout, ret;
 681         size_t size;
 682
 683         di = sdi->driver;
 684         drvc = di->context;
 685         devc = sdi->priv;
 686
 687         devc->ctx = drvc->sr_ctx;
 688         devc->sent_samples = 0;
 689         devc->empty_transfer_count = 0;
 690         devc->acq_aborted = FALSE;
 691
 692         if (configure_channels(sdi) != SR_OK) {
 693                 sr_err("Failed to configure channels.");
 694                 return SR_ERR;
 695         }
 696
 697         timeout = get_timeout(devc);
 698         usb_source_add(sdi->session, devc->ctx, timeout, receive_data, drvc);
 699
 700         size = get_buffer_size(devc);
 701         /* Prepare for analog sampling. */
 702         if (g_slist_length(devc->enabled_analog_channels) > 0) {
 703                 /* We need a buffer half the size of a transfer. */
 704                 devc->logic_buffer = g_try_malloc(size / 2);
 705                 devc->analog_buffer = g_try_malloc(
 706                         sizeof(float) * size / 2);
 707         }
 708         start_transfers(sdi);
 709         if ((ret = command_start_acquisition(sdi)) != SR_OK) {
 710                 fx2lafw_abort_acquisition(devc);
 711                 return ret;
 712         }
 713
 714         return SR_OK;
 715 }