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 "protocol.h"
  21
  22 extern struct sr_dev_driver ikalogic_scanalogic2_driver_info;
  23 static struct sr_dev_driver *di = &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->priv;
  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->priv;
  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 dev_context *devc;
 203         struct drv_context *drvc;
 204         struct timeval tv;
 205         int64_t current_time, time_elapsed;
 206         int ret = 0;
 207
 208         (void)fd;
 209         (void)revents;
 210
 211         if (!(sdi = cb_data))
 212                 return TRUE;
 213
 214         if (!(devc = sdi->priv))
 215                 return TRUE;
 216
 217         drvc = di->priv;
 218         current_time = g_get_monotonic_time();
 219
 220         if (devc->state == STATE_WAIT_DATA_READY &&
 221                         !devc->wait_data_ready_locked) {
 222                 time_elapsed = current_time - devc->wait_data_ready_time;
 223
 224                 /*
 225                  * Check here for stopping in addition to the transfer
 226                  * callback functions to avoid waiting until the
 227                  * WAIT_DATA_READY_INTERVAL has expired.
 228                  */
 229                 if (sdi->status == SR_ST_STOPPING) {
 230                         if (!devc->stopping_in_progress) {
 231                                 devc->next_state = STATE_RESET_AND_IDLE;
 232                                 devc->stopping_in_progress = TRUE;
 233                                 ret = libusb_submit_transfer(devc->xfer_in);
 234                         }
 235                 } else if (time_elapsed >= WAIT_DATA_READY_INTERVAL) {
 236                         devc->wait_data_ready_locked = TRUE;
 237                         ret = libusb_submit_transfer(devc->xfer_in);
 238                 }
 239         }
 240
 241         if (ret != 0) {
 242                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
 243                 abort_acquisition(sdi);
 244                 return TRUE;
 245         }
 246
 247         tv.tv_sec = 0;
 248         tv.tv_usec = 0;
 249
 250         libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx, &tv,
 251                 NULL);
 252
 253         /* Check if an error occurred on a transfer. */
 254         if (devc->transfer_error)
 255                 abort_acquisition(sdi);
 256
 257         return TRUE;
 258 }
 259
 260 SR_PRIV void sl2_receive_transfer_in( struct libusb_transfer *transfer)
 261 {
 262         struct sr_dev_inst *sdi;
 263         struct dev_context *devc;
 264         uint8_t last_channel;
 265         int ret = 0;
 266
 267         sdi = transfer->user_data;
 268         devc = sdi->priv;
 269
 270         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 271                 sr_err("Transfer to device failed: %i.", transfer->status);
 272                 devc->transfer_error = TRUE;
 273                 return;
 274         }
 275
 276         if (sdi->status == SR_ST_STOPPING && !devc->stopping_in_progress) {
 277                 devc->next_state = STATE_RESET_AND_IDLE;
 278                 devc->stopping_in_progress = TRUE;
 279
 280                 if (libusb_submit_transfer(devc->xfer_in) != 0) {
 281                         sr_err("Submit transfer failed: %s.",
 282                                 libusb_error_name(ret));
 283                         devc->transfer_error = TRUE;
 284                 }
 285
 286                 return;
 287         }
 288
 289         if (devc->state != devc->next_state)
 290                 sr_spew("State changed from %i to %i.",
 291                         devc->state, devc->next_state);
 292         devc->state = devc->next_state;
 293
 294         if (devc->state == STATE_WAIT_DATA_READY) {
 295                 /* Check if the received data are a valid device status. */
 296                 if (devc->xfer_data_in[0] == 0x05) {
 297                         if (devc->xfer_data_in[1] == STATUS_WAITING_FOR_TRIGGER)
 298                                 sr_dbg("Waiting for trigger.");
 299                         else if (devc->xfer_data_in[1] == STATUS_SAMPLING)
 300                                 sr_dbg("Sampling in progress.");
 301                 }
 302
 303                 /*
 304                  * Check if the received data are a valid device status and the
 305                  * sample data are ready.
 306                  */
 307                 if (devc->xfer_data_in[0] == 0x05 &&
 308                                 devc->xfer_data_in[1] == STATUS_DATA_READY) {
 309                         devc->next_state = STATE_RECEIVE_DATA;
 310                         ret = libusb_submit_transfer(transfer);
 311                 } else {
 312                         devc->wait_data_ready_locked = FALSE;
 313                         devc->wait_data_ready_time = g_get_monotonic_time();
 314                 }
 315         } else if (devc->state == STATE_RECEIVE_DATA) {
 316                 last_channel = devc->channel_map[devc->num_enabled_channels - 1];
 317
 318                 if (devc->channel < last_channel) {
 319                         buffer_sample_data(sdi);
 320                 } else if (devc->channel == last_channel) {
 321                         process_sample_data(sdi);
 322                 } else {
 323                         /*
 324                          * Stop acquisition because all samples of enabled
 325                          * channels are processed.
 326                          */
 327                         devc->next_state = STATE_RESET_AND_IDLE;
 328                 }
 329
 330                 devc->sample_packet++;
 331                 devc->sample_packet %= devc->num_sample_packets;
 332
 333                 if (devc->sample_packet == 0)
 334                         devc->channel++;
 335
 336                 ret = libusb_submit_transfer(transfer);
 337         } else if (devc->state == STATE_RESET_AND_IDLE) {
 338                 /* Check if the received data are a valid device status. */
 339                 if (devc->xfer_data_in[0] == 0x05) {
 340                         if (devc->xfer_data_in[1] == STATUS_DEVICE_READY) {
 341                                 devc->next_state = STATE_IDLE;
 342                                 devc->xfer_data_out[0] = CMD_IDLE;
 343                         } else {
 344                                 devc->next_state = STATE_WAIT_DEVICE_READY;
 345                                 devc->xfer_data_out[0] = CMD_RESET;
 346                         }
 347
 348                         ret = libusb_submit_transfer(devc->xfer_out);
 349                 } else {
 350                         /*
 351                          * The received device status is invalid which
 352                          * indicates that the device is not ready to accept
 353                          * commands. Request a new device status until a valid
 354                          * device status is received.
 355                          */
 356                         ret = libusb_submit_transfer(transfer);
 357                 }
 358         } else if (devc->state == STATE_WAIT_DEVICE_READY) {
 359                 /* Check if the received data are a valid device status. */
 360                 if (devc->xfer_data_in[0] == 0x05) {
 361                         if (devc->xfer_data_in[1] == STATUS_DEVICE_READY) {
 362                                 devc->next_state = STATE_IDLE;
 363                                 devc->xfer_data_out[0] = CMD_IDLE;
 364                         } else {
 365                                 /*
 366                                  * The received device status is valid but the
 367                                  * device is not ready. Probably the device did
 368                                  * not recognize the last reset. Reset the
 369                                  * device again.
 370                                  */
 371                                 devc->xfer_data_out[0] = CMD_RESET;
 372                         }
 373
 374                         ret = libusb_submit_transfer(devc->xfer_out);
 375                 } else {
 376                         /*
 377                          * The device is not ready and therefore not able to
 378                          * change to the idle state. Request a new device
 379                          * status until the device is ready.
 380                          */
 381                         ret = libusb_submit_transfer(transfer);
 382                 }
 383         }
 384
 385         if (ret != 0) {
 386                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
 387                 devc->transfer_error = TRUE;
 388         }
 389 }
 390
 391 SR_PRIV void sl2_receive_transfer_out( struct libusb_transfer *transfer)
 392 {
 393         struct sr_dev_inst *sdi;
 394         struct dev_context *devc;
 395         int ret = 0;
 396
 397         sdi = transfer->user_data;
 398         devc = sdi->priv;
 399
 400         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 401                 sr_err("Transfer to device failed: %i.", transfer->status);
 402                 devc->transfer_error = TRUE;
 403                 return;
 404         }
 405
 406         if (sdi->status == SR_ST_STOPPING && !devc->stopping_in_progress) {
 407                 devc->next_state = STATE_RESET_AND_IDLE;
 408                 devc->stopping_in_progress = TRUE;
 409
 410                 if (libusb_submit_transfer(devc->xfer_in) != 0) {
 411                         sr_err("Submit transfer failed: %s.",
 412                                 libusb_error_name(ret));
 413
 414                         devc->transfer_error = TRUE;
 415                 }
 416
 417                 return;
 418         }
 419
 420         if (devc->state != devc->next_state)
 421                 sr_spew("State changed from %i to %i.",
 422                         devc->state, devc->next_state);
 423         devc->state = devc->next_state;
 424
 425         if (devc->state == STATE_IDLE) {
 426                 stop_acquisition(sdi);
 427         } else if (devc->state == STATE_SAMPLE) {
 428                 devc->next_state = STATE_WAIT_DATA_READY;
 429                 ret = libusb_submit_transfer(devc->xfer_in);
 430         } else if (devc->state == STATE_WAIT_DEVICE_READY) {
 431                 ret = libusb_submit_transfer(devc->xfer_in);
 432         }
 433
 434         if (ret != 0) {
 435                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
 436                 devc->transfer_error = TRUE;
 437         }
 438 }
 439
 440 SR_PRIV int sl2_set_samplerate(const struct sr_dev_inst *sdi,
 441                 uint64_t samplerate)
 442 {
 443         struct dev_context *devc;
 444         unsigned int i;
 445
 446         devc = sdi->priv;
 447
 448         for (i = 0; i < NUM_SAMPLERATES; i++) {
 449                 if (sl2_samplerates[i] == samplerate) {
 450                         devc->samplerate = samplerate;
 451                         devc->samplerate_id = NUM_SAMPLERATES - i - 1;
 452                         return SR_OK;
 453                 }
 454         }
 455
 456         return SR_ERR_ARG;
 457 }
 458
 459 SR_PRIV int sl2_set_limit_samples(const struct sr_dev_inst *sdi,
 460                                   uint64_t limit_samples)
 461 {
 462         struct dev_context *devc;
 463
 464         devc = sdi->priv;
 465
 466         if (limit_samples == 0) {
 467                 sr_err("Invalid number of limit samples: %" PRIu64 ".",
 468                         limit_samples);
 469                 return SR_ERR_ARG;
 470         }
 471
 472         if (limit_samples > MAX_SAMPLES)
 473                 limit_samples = MAX_SAMPLES;
 474
 475         sr_dbg("Limit samples set to %" PRIu64 ".", limit_samples);
 476
 477         devc->limit_samples = limit_samples;
 478
 479         return SR_OK;
 480 }
 481
 482 SR_PRIV int sl2_convert_trigger(const struct sr_dev_inst *sdi)
 483 {
 484         struct dev_context *devc;
 485         struct sr_trigger *trigger;
 486         struct sr_trigger_stage *stage;
 487         struct sr_trigger_match *match;
 488         const GSList *l, *m;
 489         int num_triggers_anyedge;
 490
 491         devc = sdi->priv;
 492
 493         /* Disable the trigger by default. */
 494         devc->trigger_channel = TRIGGER_CHANNEL_0;
 495         devc->trigger_type = TRIGGER_TYPE_NONE;
 496
 497         if (!(trigger = sr_session_trigger_get(sdi->session)))
 498                 return SR_OK;
 499
 500         if (g_slist_length(trigger->stages) > 1) {
 501                 sr_err("This device only supports 1 trigger stage.");
 502                 return SR_ERR;
 503         }
 504
 505         num_triggers_anyedge = 0;
 506         for (l = trigger->stages; l; l = l->next) {
 507                 stage = l->data;
 508                 for (m = stage->matches; m; m = m->next) {
 509                         match = m->data;
 510                         if (!match->channel->enabled)
 511                                 /* Ignore disabled channels with a trigger. */
 512                                 continue;
 513                         devc->trigger_channel = match->channel->index + 1;
 514                         switch (match->match) {
 515                         case SR_TRIGGER_RISING:
 516                                 devc->trigger_type = TRIGGER_TYPE_POSEDGE;
 517                                 break;
 518                         case SR_TRIGGER_FALLING:
 519                                 devc->trigger_type = TRIGGER_TYPE_NEGEDGE;
 520                                 break;
 521                         case SR_TRIGGER_EDGE:
 522                                 devc->trigger_type = TRIGGER_TYPE_ANYEDGE;
 523                                 num_triggers_anyedge++;
 524                                 break;
 525                         }
 526                 }
 527         }
 528
 529         /*
 530          * Set trigger to any edge on all channels if the trigger for each
 531          * channel is set to any edge.
 532          */
 533         if (num_triggers_anyedge == NUM_CHANNELS) {
 534                 devc->trigger_channel = TRIGGER_CHANNEL_ALL;
 535                 devc->trigger_type = TRIGGER_TYPE_ANYEDGE;
 536         }
 537
 538         sr_dbg("Trigger set to channel 0x%02x and type 0x%02x.",
 539                 devc->trigger_channel, devc->trigger_type);
 540
 541         return SR_OK;
 542 }
 543
 544 SR_PRIV int sl2_set_capture_ratio(const struct sr_dev_inst *sdi,
 545                                   uint64_t capture_ratio)
 546 {
 547         struct dev_context *devc;
 548
 549         devc = sdi->priv;
 550
 551         if (capture_ratio > 100) {
 552                 sr_err("Invalid capture ratio: %" PRIu64 " %%.", capture_ratio);
 553                 return SR_ERR_ARG;
 554         }
 555
 556         sr_info("Capture ratio set to %" PRIu64 " %%.", capture_ratio);
 557
 558         devc->capture_ratio = capture_ratio;
 559
 560         return SR_OK;
 561 }
 562
 563 SR_PRIV int sl2_set_after_trigger_delay(const struct sr_dev_inst *sdi,
 564                                         uint64_t after_trigger_delay)
 565 {
 566         struct dev_context *devc;
 567
 568         devc = sdi->priv;
 569
 570         if (after_trigger_delay > MAX_AFTER_TRIGGER_DELAY) {
 571                 sr_err("Invalid after trigger delay: %" PRIu64 " ms.",
 572                         after_trigger_delay);
 573                 return SR_ERR_ARG;
 574         }
 575
 576         sr_info("After trigger delay set to %" PRIu64 " ms.",
 577                 after_trigger_delay);
 578
 579         devc->after_trigger_delay = after_trigger_delay;
 580
 581         return SR_OK;
 582 }
 583
 584 SR_PRIV void sl2_calculate_trigger_samples(const struct sr_dev_inst *sdi)
 585 {
 586         struct dev_context *devc;
 587         uint64_t pre_trigger_samples, post_trigger_samples;
 588         uint16_t pre_trigger_bytes, post_trigger_bytes;
 589         uint8_t cr;
 590
 591         devc = sdi->priv;
 592         cr = devc->capture_ratio;
 593
 594         /* Ignore the capture ratio if no trigger is enabled. */
 595         if (devc->trigger_type == TRIGGER_TYPE_NONE)
 596                 cr = 0;
 597
 598         pre_trigger_samples = (devc->limit_samples * cr) / 100;
 599         post_trigger_samples = (devc->limit_samples * (100 - cr)) / 100;
 600
 601         /*
 602          * Increase the number of post trigger samples by one to compensate the
 603          * possible loss of a sample through integer rounding.
 604          */
 605         if (pre_trigger_samples + post_trigger_samples != devc->limit_samples)
 606                 post_trigger_samples++;
 607
 608         /*
 609          * The device requires the number of samples in multiples of 8 which
 610          * will also be called sample bytes in the following.
 611          */
 612         pre_trigger_bytes = pre_trigger_samples / 8;
 613         post_trigger_bytes = post_trigger_samples / 8;
 614
 615         /*
 616          * Round up the number of sample bytes to ensure that at least the
 617          * requested number of samples will be acquired. Note that due to this
 618          * rounding the buffer to store these sample bytes needs to be at least
 619          * one sample byte larger than the minimal number of sample bytes
 620          * needed to store the requested samples.
 621          */
 622         if (pre_trigger_samples % 8 != 0)
 623                 pre_trigger_bytes++;
 624
 625         if (post_trigger_samples % 8 != 0)
 626                 post_trigger_bytes++;
 627
 628         sr_info("Pre trigger samples: %" PRIu64 ".", pre_trigger_samples);
 629         sr_info("Post trigger samples: %" PRIu64 ".", post_trigger_samples);
 630         sr_dbg("Pre trigger sample bytes: %" PRIu16 ".", pre_trigger_bytes);
 631         sr_dbg("Post trigger sample bytes: %" PRIu16 ".", post_trigger_bytes);
 632
 633         devc->pre_trigger_samples = pre_trigger_samples;
 634         devc->pre_trigger_bytes = pre_trigger_bytes;
 635         devc->post_trigger_bytes = post_trigger_bytes;
 636 }
 637
 638 SR_PRIV int sl2_get_device_info(struct sr_usb_dev_inst usb,
 639                 struct device_info *dev_info)
 640 {
 641         struct drv_context *drvc;
 642         uint8_t buffer[PACKET_LENGTH];
 643         int ret;
 644
 645         drvc = di->priv;
 646
 647         if (!dev_info)
 648                 return SR_ERR_ARG;
 649
 650         if (sr_usb_open(drvc->sr_ctx->libusb_ctx, &usb) != SR_OK)
 651                 return SR_ERR;
 652
 653         /*
 654          * Determine if a kernel driver is active on this interface and, if so,
 655          * detach it.
 656          */
 657         if (libusb_kernel_driver_active(usb.devhdl, USB_INTERFACE) == 1) {
 658                 ret = libusb_detach_kernel_driver(usb.devhdl,
 659                         USB_INTERFACE);
 660
 661                 if (ret < 0) {
 662                         sr_err("Failed to detach kernel driver: %s.",
 663                                 libusb_error_name(ret));
 664                         libusb_close(usb.devhdl);
 665                         return SR_ERR;
 666                 }
 667         }
 668
 669         ret = libusb_claim_interface(usb.devhdl, USB_INTERFACE);
 670
 671         if (ret) {
 672                 sr_err("Failed to claim interface: %s.",
 673                         libusb_error_name(ret));
 674                 libusb_close(usb.devhdl);
 675                 return SR_ERR;
 676         }
 677
 678         memset(buffer, 0, sizeof(buffer));
 679
 680         /*
 681          * Reset the device to ensure it is in a proper state to request the
 682          * device information.
 683          */
 684         buffer[0] = CMD_RESET;
 685         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 686                 sr_err("Resetting of device failed: %s.",
 687                         libusb_error_name(ret));
 688                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 689                 libusb_close(usb.devhdl);
 690                 return SR_ERR;
 691         }
 692
 693         buffer[0] = CMD_INFO;
 694         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 695                 sr_err("Requesting of device information failed: %s.",
 696                         libusb_error_name(ret));
 697                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 698                 libusb_close(usb.devhdl);
 699                 return SR_ERR;
 700         }
 701
 702         if ((ret = sl2_transfer_in(usb.devhdl, buffer)) != PACKET_LENGTH) {
 703                 sr_err("Receiving of device information failed: %s.",
 704                         libusb_error_name(ret));
 705                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 706                 libusb_close(usb.devhdl);
 707                 return SR_ERR;
 708         }
 709
 710         memcpy(&(dev_info->serial), buffer + 1, sizeof(uint32_t));
 711         dev_info->serial = GUINT32_FROM_LE(dev_info->serial);
 712
 713         dev_info->fw_ver_major = buffer[5];
 714         dev_info->fw_ver_minor = buffer[6];
 715
 716         buffer[0] = CMD_RESET;
 717         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 718                 sr_err("Device reset failed: %s.", libusb_error_name(ret));
 719                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 720                 libusb_close(usb.devhdl);
 721                 return SR_ERR;
 722         }
 723
 724         /*
 725          * Set the device to idle state. If the device is not in idle state it
 726          * possibly will reset itself after a few seconds without being used
 727          * and thereby close the connection.
 728          */
 729         buffer[0] = CMD_IDLE;
 730         if ((ret = sl2_transfer_out(usb.devhdl, buffer)) != PACKET_LENGTH) {
 731                 sr_err("Failed to set device in idle state: %s.",
 732                         libusb_error_name(ret));
 733                 libusb_release_interface(usb.devhdl, USB_INTERFACE);
 734                 libusb_close(usb.devhdl);
 735                 return SR_ERR;
 736         }
 737
 738         ret = libusb_release_interface(usb.devhdl, USB_INTERFACE);
 739
 740         if (ret < 0) {
 741                 sr_err("Failed to release interface: %s.",
 742                         libusb_error_name(ret));
 743                 libusb_close(usb.devhdl);
 744                 return SR_ERR;
 745         }
 746
 747         libusb_close(usb.devhdl);
 748
 749         return SR_OK;
 750 }
 751
 752 SR_PRIV int sl2_transfer_in(libusb_device_handle *dev_handle, uint8_t *data)
 753 {
 754         return libusb_control_transfer(dev_handle, USB_REQUEST_TYPE_IN,
 755                 USB_HID_GET_REPORT, USB_HID_REPORT_TYPE_FEATURE, USB_INTERFACE,
 756                 (unsigned char *)data, PACKET_LENGTH, USB_TIMEOUT);
 757 }
 758
 759 SR_PRIV int sl2_transfer_out(libusb_device_handle *dev_handle, uint8_t *data)
 760 {
 761         return libusb_control_transfer(dev_handle, USB_REQUEST_TYPE_OUT,
 762                 USB_HID_SET_REPORT, USB_HID_REPORT_TYPE_FEATURE, USB_INTERFACE,
 763                 (unsigned char *)data, PACKET_LENGTH, USB_TIMEOUT);
 764 }