src/hardware/ikalogic-scanalogic2/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2013 Marc Schink <sigrok-dev@marcschink.de>
   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 "protocol.h"
  22
  23 extern struct sr_dev_driver ikalogic_scanalogic2_driver_info;
  24
  25 extern uint64_t sl2_samplerates[NUM_SAMPLERATES];
  26
  27 static void stop_acquisition(struct sr_dev_inst *sdi)
  28 {
  29         struct drv_context *drvc = sdi->driver->context;
  30         struct dev_context *devc;
  31         struct sr_datafeed_packet packet;
  32
  33         devc = sdi->priv;
  34
  35         /* Remove USB file descriptors from polling. */
  36         usb_source_remove(sdi->session, drvc->sr_ctx);
  37
  38         packet.type = SR_DF_END;
  39         sr_session_send(devc->cb_data, &packet);
  40
  41         sdi->status = SR_ST_ACTIVE;
  42 }
  43
  44 static void abort_acquisition(struct sr_dev_inst *sdi)
  45 {
  46         struct drv_context *drvc = sdi->driver->context;
  47         struct dev_context *devc;
  48         struct sr_datafeed_packet packet;
  49
  50         devc = sdi->priv;
  51
  52         /* Remove USB file descriptors from polling. */
  53         usb_source_remove(sdi->session, drvc->sr_ctx);
  54
  55         packet.type = SR_DF_END;
  56         sr_session_send(devc->cb_data, &packet);
  57
  58         sdi->driver->dev_close(sdi);
  59 }
  60
  61 static void buffer_sample_data(const struct sr_dev_inst *sdi)
  62 {
  63         struct dev_context *devc;
  64         unsigned int offset, packet_length;
  65
  66         devc = sdi->priv;
  67
  68         if (devc->channels[devc->channel]->enabled) {
  69                 offset = devc->sample_packet * PACKET_NUM_SAMPLE_BYTES;
  70
  71                 /*
  72                  * Determine the packet length to ensure that the last packet
  73                  * will not exceed the buffer size.
  74                  */
  75                 packet_length = MIN(PACKET_NUM_SAMPLE_BYTES,
  76                         MAX_DEV_SAMPLE_BYTES - offset);
  77
  78                 /*
  79                  * Skip the first 4 bytes of the source buffer because they
  80                  * contain channel and packet information only.
  81                  */
  82                 memcpy(devc->sample_buffer[devc->channel] + offset,
  83                         devc->xfer_data_in + 4, packet_length);
  84         }
  85 }
  86
  87 static void process_sample_data(const struct sr_dev_inst *sdi)
  88 {
  89         struct dev_context *devc;
  90         struct sr_datafeed_packet packet;
  91         struct sr_datafeed_logic logic;
  92         uint8_t i, j, tmp, buffer[PACKET_NUM_SAMPLES], *ptr[NUM_CHANNELS];
  93         uint16_t offset, n = 0;
  94         int8_t k;
  95
  96         devc = sdi->priv;
  97         offset = devc->sample_packet * PACKET_NUM_SAMPLE_BYTES;
  98
  99         /*
 100          * Array of pointers to the sample data of all channels up to the last
 101          * enabled one for an uniform access to them. Note that the currently
 102          * received samples always belong to the last enabled channel.
 103          */
 104         for (i = 0; i < devc->num_enabled_channels - 1; i++)
 105                 ptr[i] = devc->sample_buffer[devc->channel_map[i]] + offset;
 106
 107         /*
 108          * Skip the first 4 bytes of the buffer because they contain channel
 109          * and packet information only.
 110          */
 111         ptr[i] = devc->xfer_data_in + 4;
 112
 113         for (i = 0; i < PACKET_NUM_SAMPLE_BYTES; i++) {
 114                 /* Stop processing if all requested samples are processed. */
 115                 if (devc->samples_processed == devc->limit_samples)
 116                         break;
 117
 118                 k = 7;
 119
 120                 if (devc->samples_processed == 0) {
 121                         /*
 122                          * Adjust the position of the first sample to be
 123                          * processed because possibly more samples than
 124                          * necessary might have been acquired. This is because
 125                          * the number of acquired samples is always rounded up
 126                          * to a multiple of 8.
 127                          */
 128                         k = k - (devc->pre_trigger_bytes * 8) +
 129                                 devc->pre_trigger_samples;
 130
 131                         sr_dbg("Start processing at sample: %d.", 7 - k);
 132
 133                         /*
 134                          * Send the trigger before the first sample is
 135                          * processed if no pre trigger samples were calculated
 136                          * through the capture ratio.
 137                          */
 138                         if (devc->trigger_type != TRIGGER_TYPE_NONE &&
 139                                         devc->pre_trigger_samples == 0) {
 140                                 packet.type = SR_DF_TRIGGER;
 141                                 sr_session_send(devc->cb_data, &packet);
 142                         }
 143                 }
 144
 145                 for (; k >= 0; k--) {
 146                         /*
 147                          * Stop processing if all requested samples are
 148                          * processed.
 149                          */
 150                         if (devc->samples_processed == devc->limit_samples)
 151                                 break;
 152
 153                         buffer[n] = 0;
 154
 155                         /*
 156                          * Extract the current sample for each enabled channel
 157                          * and store them in the buffer.
 158                          */
 159                         for (j = 0; j < devc->num_enabled_channels; j++) {
 160                                 tmp = (ptr[j][i] & (1 << k)) >> k;
 161                                 buffer[n] |= tmp << devc->channel_map[j];
 162                         }
 163
 164                         n++;
 165                         devc->samples_processed++;
 166
 167                         /*
 168                          * Send all processed samples and the trigger if the
 169                          * number of processed samples reaches the calculated
 170                          * number of pre trigger samples.
 171                          */
 172                         if (devc->samples_processed == devc->pre_trigger_samples &&
 173                                         devc->trigger_type != TRIGGER_TYPE_NONE) {
 174                                 packet.type = SR_DF_LOGIC;
 175                                 packet.payload = &logic;
 176                                 logic.length = n;
 177                                 logic.unitsize = 1;
 178                                 logic.data = buffer;
 179                                 sr_session_send(devc->cb_data, &packet);
 180
 181                                 packet.type = SR_DF_TRIGGER;
 182                                 sr_session_send(devc->cb_data, &packet);
 183
 184                                 n = 0;
 185                         }
 186                 }
 187         }
 188
 189         if (n > 0) {
 190                 packet.type = SR_DF_LOGIC;
 191                 packet.payload = &logic;
 192                 logic.length = n;
 193                 logic.unitsize = 1;
 194                 logic.data = buffer;
 195                 sr_session_send(devc->cb_data, &packet);
 196         }
 197 }
 198
 199 SR_PRIV int ikalogic_scanalogic2_receive_data(int fd, int revents, void *cb_data)
 200 {
 201         struct sr_dev_inst *sdi;
 202         struct sr_dev_driver *di;
 203         struct dev_context *devc;
 204         struct drv_context *drvc;
 205         struct timeval tv;
 206         int64_t current_time, time_elapsed;
 207         int ret = 0;
 208
 209         (void)fd;
 210         (void)revents;
 211
 212         if (!(sdi = cb_data))
 213                 return TRUE;
 214
 215         if (!(devc = sdi->priv))
 216                 return TRUE;
 217
 218         di = sdi->driver;
 219         drvc = di->context;
 220         current_time = g_get_monotonic_time();
 221
 222         if (devc->state == STATE_WAIT_DATA_READY &&
 223                         !devc->wait_data_ready_locked) {
 224                 time_elapsed = current_time - devc->wait_data_ready_time;
 225
 226                 /*
 227                  * Check here for stopping in addition to the transfer
 228                  * callback functions to avoid waiting until the
 229                  * WAIT_DATA_READY_INTERVAL has expired.
 230                  */
 231                 if (sdi->status == SR_ST_STOPPING) {
 232                         if (!devc->stopping_in_progress) {
 233                                 devc->next_state = STATE_RESET_AND_IDLE;
 234                                 devc->stopping_in_progress = TRUE;
 235                                 ret = libusb_submit_transfer(devc->xfer_in);
 236                         }
 237                 } else if (time_elapsed >= WAIT_DATA_READY_INTERVAL) {
 238                         devc->wait_data_ready_locked = TRUE;
 239                         ret = libusb_submit_transfer(devc->xfer_in);
 240                 }
 241         }
 242
 243         if (ret != 0) {
 244                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
 245                 abort_acquisition(sdi);
 246                 return TRUE;
 247         }
 248
 249         tv.tv_sec = 0;
 250         tv.tv_usec = 0;
 251
 252         libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
 253                 NULL);
 254
 255         /* Check if an error occurred on a transfer. */
 256         if (devc->transfer_error)
 257                 abort_acquisition(sdi);
 258
 259         return TRUE;
 260 }
 261
 262 SR_PRIV void LIBUSB_CALL sl2_receive_transfer_in( struct libusb_transfer *transfer)
 263 {
 264         struct sr_dev_inst *sdi;
 265         struct dev_context *devc;
 266         uint8_t last_channel;
 267         int ret = 0;
 268
 269         sdi = transfer->user_data;
 270         devc = sdi->priv;
 271
 272         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 273                 sr_err("Transfer to device failed: %i.", transfer->status);
 274                 devc->transfer_error = TRUE;
 275                 return;
 276         }
 277
 278         if (sdi->status == SR_ST_STOPPING && !devc->stopping_in_progress) {
 279                 devc->next_state = STATE_RESET_AND_IDLE;
 280                 devc->stopping_in_progress = TRUE;
 281
 282                 if (libusb_submit_transfer(devc->xfer_in) != 0) {
 283                         sr_err("Submit transfer failed: %s.",
 284                                 libusb_error_name(ret));
 285                         devc->transfer_error = TRUE;
 286                 }
 287
 288                 return;
 289         }
 290
 291         if (devc->state != devc->next_state)
 292                 sr_spew("State changed from %i to %i.",
 293                         devc->state, devc->next_state);
 294         devc->state = devc->next_state;
 295
 296         if (devc->state == STATE_WAIT_DATA_READY) {
 297                 /* Check if the received data are a valid device status. */
 298                 if (devc->xfer_data_in[0] == 0x05) {
 299                         if (devc->xfer_data_in[1] == STATUS_WAITING_FOR_TRIGGER)
 300                                 sr_dbg("Waiting for trigger.");
 301                         else if (devc->xfer_data_in[1] == STATUS_SAMPLING)
 302                                 sr_dbg("Sampling in progress.");
 303                 }
 304
 305                 /*
 306                  * Check if the received data are a valid device status and the
 307                  * sample data are ready.
 308                  */
 309                 if (devc->xfer_data_in[0] == 0x05 &&
 310                                 devc->xfer_data_in[1] == STATUS_DATA_READY) {
 311                         devc->next_state = STATE_RECEIVE_DATA;
 312                         ret = libusb_submit_transfer(transfer);
 313                 } else {
 314                         devc->wait_data_ready_locked = FALSE;
 315                         devc->wait_data_ready_time = g_get_monotonic_time();
 316                 }
 317         } else if (devc->state == STATE_RECEIVE_DATA) {
 318                 last_channel = devc->channel_map[devc->num_enabled_channels - 1];
 319
 320                 if (devc->channel < last_channel) {
 321                         buffer_sample_data(sdi);
 322                 } else if (devc->channel == last_channel) {
 323                         process_sample_data(sdi);
 324                 } else {
 325                         /*
 326                          * Stop acquisition because all samples of enabled
 327                          * channels are processed.
 328                          */
 329                         devc->next_state = STATE_RESET_AND_IDLE;
 330                 }
 331
 332                 devc->sample_packet++;
 333                 devc->sample_packet %= devc->num_sample_packets;
 334
 335                 if (devc->sample_packet == 0)
 336                         devc->channel++;
 337
 338                 ret = libusb_submit_transfer(transfer);
 339         } else if (devc->state == STATE_RESET_AND_IDLE) {
 340                 /* Check if the received data are a valid device status. */
 341                 if (devc->xfer_data_in[0] == 0x05) {
 342                         if (devc->xfer_data_in[1] == STATUS_DEVICE_READY) {
 343                                 devc->next_state = STATE_IDLE;
 344                                 devc->xfer_data_out[0] = CMD_IDLE;
 345                         } else {
 346                                 devc->next_state = STATE_WAIT_DEVICE_READY;
 347                                 devc->xfer_data_out[0] = CMD_RESET;
 348                         }
 349
 350                         ret = libusb_submit_transfer(devc->xfer_out);
 351                 } else {
 352                         /*
 353                          * The received device status is invalid which
 354                          * indicates that the device is not ready to accept
 355                          * commands. Request a new device status until a valid
 356                          * device status is received.
 357                          */
 358                         ret = libusb_submit_transfer(transfer);
 359                 }
 360         } else if (devc->state == STATE_WAIT_DEVICE_READY) {
 361                 /* Check if the received data are a valid device status. */
 362                 if (devc->xfer_data_in[0] == 0x05) {
 363                         if (devc->xfer_data_in[1] == STATUS_DEVICE_READY) {
 364                                 devc->next_state = STATE_IDLE;
 365                                 devc->xfer_data_out[0] = CMD_IDLE;
 366                         } else {
 367                                 /*
 368                                  * The received device status is valid but the
 369                                  * device is not ready. Probably the device did
 370                                  * not recognize the last reset. Reset the
 371                                  * device again.
 372                                  */
 373                                 devc->xfer_data_out[0] = CMD_RESET;
 374                         }
 375
 376                         ret = libusb_submit_transfer(devc->xfer_out);
 377                 } else {
 378                         /*
 379                          * The device is not ready and therefore not able to
 380                          * change to the idle state. Request a new device
 381                          * status until the device is ready.
 382                          */
 383                         ret = libusb_submit_transfer(transfer);
 384                 }
 385         }
 386
 387         if (ret != 0) {
 388                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
 389                 devc->transfer_error = TRUE;
 390         }
 391 }
 392
 393 SR_PRIV void LIBUSB_CALL sl2_receive_transfer_out( struct libusb_transfer *transfer)
 394 {
 395         struct sr_dev_inst *sdi;
 396         struct dev_context *devc;
 397         int ret = 0;
 398
 399         sdi = transfer->user_data;
 400         devc = sdi->priv;
 401
 402         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 403                 sr_err("Transfer to device failed: %i.", transfer->status);
 404                 devc->transfer_error = TRUE;
 405                 return;
 406         }
 407
 408         if (sdi->status == SR_ST_STOPPING && !devc->stopping_in_progress) {
 409                 devc->next_state = STATE_RESET_AND_IDLE;
 410                 devc->stopping_in_progress = TRUE;
 411
 412                 if (libusb_submit_transfer(devc->xfer_in) != 0) {
 413                         sr_err("Submit transfer failed: %s.",
 414                                 libusb_error_name(ret));
 415
 416                         devc->transfer_error = TRUE;
 417                 }
 418
 419                 return;
 420         }
 421
 422         if (devc->state != devc->next_state)
 423                 sr_spew("State changed from %i to %i.",
 424                         devc->state, devc->next_state);
 425         devc->state = devc->next_state;
 426
 427         if (devc->state == STATE_IDLE) {
 428                 stop_acquisition(sdi);
 429         } else if (devc->state == STATE_SAMPLE) {
 430                 devc->next_state = STATE_WAIT_DATA_READY;
 431                 ret = libusb_submit_transfer(devc->xfer_in);
 432         } else if (devc->state == STATE_WAIT_DEVICE_READY) {
 433                 ret = libusb_submit_transfer(devc->xfer_in);
 434         }
 435
 436         if (ret != 0) {
 437                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
 438                 devc->transfer_error = TRUE;
 439         }
 440 }
 441
 442 SR_PRIV int sl2_set_samplerate(const struct sr_dev_inst *sdi,
 443                 uint64_t samplerate)
 444 {
 445         struct dev_context *devc;
 446         unsigned int i;
 447
 448         devc = sdi->priv;
 449
 450         for (i = 0; i < NUM_SAMPLERATES; i++) {
 451                 if (sl2_samplerates[i] == samplerate) {
 452                         devc->samplerate = samplerate;
 453                         devc->samplerate_id = NUM_SAMPLERATES - i - 1;
 454                         return SR_OK;
 455                 }
 456         }
 457
 458         return SR_ERR_ARG;
 459 }
 460
 461 SR_PRIV int sl2_set_limit_samples(const struct sr_dev_inst *sdi,
 462                                   uint64_t limit_samples)
 463 {
 464         struct dev_context *devc;
 465
 466         devc = sdi->priv;
 467
 468         if (limit_samples == 0) {
 469                 sr_err("Invalid number of limit samples: %" PRIu64 ".",
 470                         limit_samples);
 471                 return SR_ERR_ARG;
 472         }
 473
 474         if (limit_samples > MAX_SAMPLES)
 475                 limit_samples = MAX_SAMPLES;
 476
 477         sr_dbg("Limit samples set to %" PRIu64 ".", limit_samples);
 478
 479         devc->limit_samples = limit_samples;
 480
 481         return SR_OK;
 482 }
 483
 484 SR_PRIV int sl2_convert_trigger(const struct sr_dev_inst *sdi)
 485 {
 486         struct dev_context *devc;
 487         struct sr_trigger *trigger;
 488         struct sr_trigger_stage *stage;
 489         struct sr_trigger_match *match;
 490         const GSList *l, *m;
 491         int num_triggers_anyedge;
 492
 493         devc = sdi->priv;
 494
 495         /* Disable the trigger by default. */
 496         devc->trigger_channel = TRIGGER_CHANNEL_0;
 497         devc->trigger_type = TRIGGER_TYPE_NONE;
 498
 499         if (!(trigger = sr_session_trigger_get(sdi->session)))
 500                 return SR_OK;
 501
 502         if (g_slist_length(trigger->stages) > 1) {
 503                 sr_err("This device only supports 1 trigger stage.");
 504                 return SR_ERR;
 505         }
 506
 507         num_triggers_anyedge = 0;
 508         for (l = trigger->stages; l; l = l->next) {
 509                 stage = l->data;
 510                 for (m = stage->matches; m; m = m->next) {
 511                         match = m->data;
 512                         if (!match->channel->enabled)
 513                                 /* Ignore disabled channels with a trigger. */
 514                                 continue;
 515                         devc->trigger_channel = match->channel->index + 1;
 516                         switch (match->match) {
 517                         case SR_TRIGGER_RISING:
 518                                 devc->trigger_type = TRIGGER_TYPE_POSEDGE;
 519                                 break;
 520                         case SR_TRIGGER_FALLING:
 521                                 devc->trigger_type = TRIGGER_TYPE_NEGEDGE;
 522                                 break;
 523                         case SR_TRIGGER_EDGE:
 524                                 devc->trigger_type = TRIGGER_TYPE_ANYEDGE;
 525                                 num_triggers_anyedge++;
 526                                 break;
 527                         }
 528                 }
 529         }
 530
 531         /*
 532          * Set trigger to any edge on all channels if the trigger for each
 533          * channel is set to any edge.
 534          */
 535         if (num_triggers_anyedge == NUM_CHANNELS) {
 536                 devc->trigger_channel = TRIGGER_CHANNEL_ALL;
 537                 devc->trigger_type = TRIGGER_TYPE_ANYEDGE;
 538         }
 539
 540         sr_dbg("Trigger set to channel 0x%02x and type 0x%02x.",
 541                 devc->trigger_channel, devc->trigger_type);
 542
 543         return SR_OK;
 544 }
 545
 546 SR_PRIV int sl2_set_capture_ratio(const struct sr_dev_inst *sdi,
 547                                   uint64_t capture_ratio)
 548 {
 549         struct dev_context *devc;
 550
 551         devc = sdi->priv;
 552
 553         if (capture_ratio > 100) {
 554                 sr_err("Invalid capture ratio: %" PRIu64 " %%.", capture_ratio);
 555                 return SR_ERR_ARG;
 556         }
 557
 558         sr_info("Capture ratio set to %" PRIu64 " %%.", capture_ratio);
 559
 560         devc->capture_ratio = capture_ratio;
 561
 562         return SR_OK;
 563 }
 564
 565 SR_PRIV int sl2_set_after_trigger_delay(const struct sr_dev_inst *sdi,
 566                                         uint64_t after_trigger_delay)
 567 {
 568         struct dev_context *devc;
 569
 570         devc = sdi->priv;
 571
 572         if (after_trigger_delay > MAX_AFTER_TRIGGER_DELAY) {
 573                 sr_err("Invalid after trigger delay: %" PRIu64 " ms.",
 574                         after_trigger_delay);
 575                 return SR_ERR_ARG;
 576         }
 577
 578         sr_info("After trigger delay set to %" PRIu64 " ms.",
 579                 after_trigger_delay);
 580
 581         devc->after_trigger_delay = after_trigger_delay;
 582
 583         return SR_OK;
 584 }
 585
 586 SR_PRIV void sl2_calculate_trigger_samples(const struct sr_dev_inst *sdi)
 587 {
 588         struct dev_context *devc;
 589         uint64_t pre_trigger_samples, post_trigger_samples;
 590         uint16_t pre_trigger_bytes, post_trigger_bytes;
 591         uint8_t cr;
 592
 593         devc = sdi->priv;
 594         cr = devc->capture_ratio;
 595
 596         /* Ignore the capture ratio if no trigger is enabled. */
 597         if (devc->trigger_type == TRIGGER_TYPE_NONE)
 598                 cr = 0;
 599
 600         pre_trigger_samples = (devc->limit_samples * cr) / 100;
 601         post_trigger_samples = (devc->limit_samples * (100 - cr)) / 100;
 602
 603         /*
 604          * Increase the number of post trigger samples by one to compensate the
 605          * possible loss of a sample through integer rounding.
 606          */
 607         if (pre_trigger_samples + post_trigger_samples != devc->limit_samples)
 608                 post_trigger_samples++;
 609
 610         /*
 611          * The device requires the number of samples in multiples of 8 which
 612          * will also be called sample bytes in the following.
 613          */
 614         pre_trigger_bytes = pre_trigger_samples / 8;
 615         post_trigger_bytes = post_trigger_samples / 8;
 616
 617         /*
 618          * Round up the number of sample bytes to ensure that at least the
 619          * requested number of samples will be acquired. Note that due to this
 620          * rounding the buffer to store these sample bytes needs to be at least
 621          * one sample byte larger than the minimal number of sample bytes
 622          * needed to store the requested samples.
 623          */
 624         if (pre_trigger_samples % 8 != 0)
 625                 pre_trigger_bytes++;
 626
 627         if (post_trigger_samples % 8 != 0)
 628                 post_trigger_bytes++;
 629
 630         sr_info("Pre trigger samples: %" PRIu64 ".", pre_trigger_samples);
 631         sr_info("Post trigger samples: %" PRIu64 ".", post_trigger_samples);
 632         sr_dbg("Pre trigger sample bytes: %" PRIu16 ".", pre_trigger_bytes);
 633         sr_dbg("Post trigger sample bytes: %" PRIu16 ".", post_trigger_bytes);
 634
 635         devc->pre_trigger_samples = pre_trigger_samples;
 636         devc->pre_trigger_bytes = pre_trigger_bytes;
 637         devc->post_trigger_bytes = post_trigger_bytes;
 638 }
 639
 640 SR_PRIV int sl2_get_device_info(struct sr_usb_dev_inst usb,
 641                 struct device_info *dev_info)
 642 {
 643         struct drv_context *drvc;
 644         uint8_t buffer[PACKET_LENGTH];
 645         int ret;
 646
 647         drvc = ikalogic_scanalogic2_driver_info.context;
 648
 649         if (!dev_info)
 650                 return SR_ERR_ARG;
 651
 652         if (sr_usb_open(drvc->sr_ctx->libusb_ctx, &usb) != SR_OK)
 653                 return SR_ERR;
 654
 655         /*
 656          * Determine if a kernel driver is active on this interface and, if so,
 657          * detach it.
 658          */
 659         if (libusb_kernel_driver_active(usb.devhdl, USB_INTERFACE) == 1) {
 660                 ret = libusb_detach_kernel_driver(usb.devhdl,
 661                         USB_INTERFACE);
 662
 663                 if (ret < 0) {
 664                         sr_err("Failed to detach kernel driver: %s.",
 665                                 libusb_error_name(ret));
 666                         libusb_close(usb.devhdl);
 667                         return SR_ERR;
 668                 }
 669         }
 670
 671         ret = libusb_claim_interface(usb.devhdl, USB_INTERFACE);
 672
 673         if (ret) {
 674                 sr_err("Failed to claim interface: %s.",
 675                         libusb_error_name(ret));
 676                 libusb_close(usb.devhdl);
 677                 return SR_ERR;
 678         }
 679
 680         memset(buffer, 0, sizeof(buffer));
 681
 682         /*
 683          * Reset the device to ensure it is in a proper state to request the
 684          * device information.
 685          */
 686         buffer[0] = CMD_RESET;
 687         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 688                 sr_err("Resetting of device failed: %s.",
 689                         libusb_error_name(ret));
 690                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 691                 libusb_close(usb.devhdl);
 692                 return SR_ERR;
 693         }
 694
 695         buffer[0] = CMD_INFO;
 696         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 697                 sr_err("Requesting of device information failed: %s.",
 698                         libusb_error_name(ret));
 699                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 700                 libusb_close(usb.devhdl);
 701                 return SR_ERR;
 702         }
 703
 704         if ((ret = sl2_transfer_in(usb.devhdl, buffer)) != PACKET_LENGTH) {
 705                 sr_err("Receiving of device information failed: %s.",
 706                         libusb_error_name(ret));
 707                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 708                 libusb_close(usb.devhdl);
 709                 return SR_ERR;
 710         }
 711
 712         memcpy(&(dev_info->serial), buffer + 1, sizeof(uint32_t));
 713         dev_info->serial = GUINT32_FROM_LE(dev_info->serial);
 714
 715         dev_info->fw_ver_major = buffer[5];
 716         dev_info->fw_ver_minor = buffer[6];
 717
 718         buffer[0] = CMD_RESET;
 719         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 720                 sr_err("Device reset failed: %s.", libusb_error_name(ret));
 721                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 722                 libusb_close(usb.devhdl);
 723                 return SR_ERR;
 724         }
 725
 726         /*
 727          * Set the device to idle state. If the device is not in idle state it
 728          * possibly will reset itself after a few seconds without being used
 729          * and thereby close the connection.
 730          */
 731         buffer[0] = CMD_IDLE;
 732         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 733                 sr_err("Failed to set device in idle state: %s.",
 734                         libusb_error_name(ret));
 735                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 736                 libusb_close(usb.devhdl);
 737                 return SR_ERR;
 738         }
 739
 740         ret = libusb_release_interface(usb.devhdl, USB_INTERFACE);
 741
 742         if (ret < 0) {
 743                 sr_err("Failed to release interface: %s.",
 744                         libusb_error_name(ret));
 745                 libusb_close(usb.devhdl);
 746                 return SR_ERR;
 747         }
 748
 749         libusb_close(usb.devhdl);
 750
 751         return SR_OK;
 752 }
 753
 754 SR_PRIV int sl2_transfer_in(libusb_device_handle *dev_handle, uint8_t *data)
 755 {
 756         return libusb_control_transfer(dev_handle, USB_REQUEST_TYPE_IN,
 757                 USB_HID_GET_REPORT, USB_HID_REPORT_TYPE_FEATURE, USB_INTERFACE,
 758                 (unsigned char *)data, PACKET_LENGTH, USB_TIMEOUT_MS);
 759 }
 760
 761 SR_PRIV int sl2_transfer_out(libusb_device_handle *dev_handle, uint8_t *data)
 762 {
 763         return libusb_control_transfer(dev_handle, USB_REQUEST_TYPE_OUT,
 764                 USB_HID_SET_REPORT, USB_HID_REPORT_TYPE_FEATURE, USB_INTERFACE,
 765                 (unsigned char *)data, PACKET_LENGTH, USB_TIMEOUT_MS);
 766 }