hardware/saleae-logic/saleae-logic.c

   1 /*
   2  * This file is part of the sigrok project.
   3  *
   4  * Copyright (C) 2010 Bert Vermeulen <bert@biot.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "config.h"
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <sys/time.h>
  24 #include <inttypes.h>
  25 #include <glib.h>
  26 #include <libusb.h>
  27 #include <sigrok.h>
  28 #include <sigrok-internal.h>
  29
  30 #define USB_VENDOR                  0x0925
  31 #define USB_PRODUCT                     0x3881
  32 #define USB_VENDOR_NAME        "Saleae"
  33 #define USB_MODEL_NAME         "Logic"
  34 #define USB_MODEL_VERSION      ""
  35
  36 #define USB_INTERFACE          0
  37 #define USB_CONFIGURATION      1
  38 #define NUM_PROBES             8
  39 #define NUM_TRIGGER_STAGES     4
  40 #define TRIGGER_TYPES          "01"
  41 #define FIRMWARE               FIRMWARE_DIR "/saleae-logic.fw"
  42
  43 /* delay in ms */
  44 #define FIRMWARE_RENUM_DELAY   2000
  45 #define NUM_SIMUL_TRANSFERS    10
  46 #define MAX_EMPTY_TRANSFERS    (NUM_SIMUL_TRANSFERS * 2)
  47
  48 /* Software trigger implementation: positive values indicate trigger stage. */
  49 #define TRIGGER_FIRED          -1
  50
  51 /* There is only one model Saleae Logic, and this is what it supports: */
  52 static int capabilities[] = {
  53         SR_HWCAP_LOGIC_ANALYZER,
  54         SR_HWCAP_SAMPLERATE,
  55
  56         /* These are really implemented in the driver, not the hardware. */
  57         SR_HWCAP_LIMIT_SAMPLES,
  58         SR_HWCAP_CONTINUOUS,
  59         0,
  60 };
  61
  62 /* List of struct sr_device_instance, maintained by opendev()/closedev(). */
  63 static GSList *device_instances = NULL;
  64
  65 /*
  66  * Since we can't keep track of a Saleae Logic device after upgrading the
  67  * firmware -- it re-enumerates into a different device address after the
  68  * upgrade -- this is like a global lock. No device will open until a proper
  69  * delay after the last device was upgraded.
  70  */
  71 static GTimeVal firmware_updated = { 0, 0 };
  72
  73 static libusb_context *usb_context = NULL;
  74
  75 static uint64_t supported_samplerates[] = {
  76         SR_KHZ(200),
  77         SR_KHZ(250),
  78         SR_KHZ(500),
  79         SR_MHZ(1),
  80         SR_MHZ(2),
  81         SR_MHZ(4),
  82         SR_MHZ(8),
  83         SR_MHZ(12),
  84         SR_MHZ(16),
  85         SR_MHZ(24),
  86         0,
  87 };
  88
  89 static struct sr_samplerates samplerates = {
  90         SR_KHZ(200),
  91         SR_MHZ(24),
  92         SR_HZ(0),
  93         supported_samplerates,
  94 };
  95
  96 /* TODO: All of these should go in a device-specific struct. */
  97 static uint64_t cur_samplerate = 0;
  98 static uint64_t limit_samples = 0;
  99 static uint8_t probe_mask = 0;
 100 static uint8_t trigger_mask[NUM_TRIGGER_STAGES] = { 0 };
 101 static uint8_t trigger_value[NUM_TRIGGER_STAGES] = { 0 };
 102 static uint8_t trigger_buffer[NUM_TRIGGER_STAGES] = { 0 };
 103
 104 static int trigger_stage = TRIGGER_FIRED;
 105
 106 static int hw_set_configuration(int device_index, int capability, void *value);
 107 static void hw_stop_acquisition(int device_index, gpointer session_device_id);
 108
 109 /**
 110  * Check the USB configuration to determine if this is a Saleae Logic.
 111  *
 112  * @return 1 if the device's configuration profile match the Logic firmware's
 113  *         configuration, 0 otherwise.
 114  */
 115 static int check_conf_profile(libusb_device *dev)
 116 {
 117         struct libusb_device_descriptor des;
 118         struct libusb_config_descriptor *conf_dsc = NULL;
 119         const struct libusb_interface_descriptor *intf_dsc;
 120         int ret = -1;
 121
 122         while (ret == -1) {
 123                 /* Assume it's not a Saleae Logic unless proven wrong. */
 124                 ret = 0;
 125
 126                 if (libusb_get_device_descriptor(dev, &des) != 0)
 127                         break;
 128
 129                 if (des.bNumConfigurations != 1)
 130                         /* Need exactly 1 configuration. */
 131                         break;
 132
 133                 if (libusb_get_config_descriptor(dev, 0, &conf_dsc) != 0)
 134                         break;
 135
 136                 if (conf_dsc->bNumInterfaces != 1)
 137                         /* Need exactly 1 interface. */
 138                         break;
 139
 140                 if (conf_dsc->interface[0].num_altsetting != 1)
 141                         /* Need just one alternate setting. */
 142                         break;
 143
 144                 intf_dsc = &(conf_dsc->interface[0].altsetting[0]);
 145                 if (intf_dsc->bNumEndpoints != 2)
 146                         /* Need 2 endpoints. */
 147                         break;
 148
 149                 if ((intf_dsc->endpoint[0].bEndpointAddress & 0x8f) !=
 150                     (1 | LIBUSB_ENDPOINT_OUT))
 151                         /* First endpoint should be 1 (outbound). */
 152                         break;
 153
 154                 if ((intf_dsc->endpoint[1].bEndpointAddress & 0x8f) !=
 155                     (2 | LIBUSB_ENDPOINT_IN))
 156                         /* First endpoint should be 2 (inbound). */
 157                         break;
 158
 159                 /* If we made it here, it must be a Saleae Logic. */
 160                 ret = 1;
 161         }
 162
 163         if (conf_dsc)
 164                 libusb_free_config_descriptor(conf_dsc);
 165
 166         return ret;
 167 }
 168
 169 static struct sr_device_instance *sl_open_device(int device_index)
 170 {
 171         struct sr_device_instance *sdi;
 172         libusb_device **devlist;
 173         struct libusb_device_descriptor des;
 174         int err, skip, i;
 175
 176         if (!(sdi = sr_get_device_instance(device_instances, device_index)))
 177                 return NULL;
 178
 179         libusb_get_device_list(usb_context, &devlist);
 180         if (sdi->status == SR_ST_INITIALIZING) {
 181                 /*
 182                  * This device was renumerating last time we touched it.
 183                  * opendev() guarantees we've waited long enough for it to
 184                  * have booted properly, so now we need to find it on
 185                  * the bus and record its new address.
 186                  */
 187                 skip = 0;
 188                 for (i = 0; devlist[i]; i++) {
 189                         /* TODO: Error handling. */
 190                         err = opendev2(device_index, &sdi, devlist[i], &des,
 191                                        &skip, USB_VENDOR, USB_PRODUCT,
 192                                        USB_INTERFACE);
 193                 }
 194         } else if (sdi->status == SR_ST_INACTIVE) {
 195                 /*
 196                  * This device is fully enumerated, so we need to find this
 197                  * device by vendor, product, bus and address.
 198                  */
 199                 libusb_get_device_list(usb_context, &devlist);
 200                 for (i = 0; devlist[i]; i++) {
 201                         /* TODO: Error handling. */
 202                         err = opendev3(&sdi, devlist[i], &des, USB_VENDOR,
 203                                        USB_PRODUCT, USB_INTERFACE);
 204                 }
 205         } else {
 206                 /* Status must be SR_ST_ACTIVE, i.e. already in use... */
 207                 sdi = NULL;
 208         }
 209         libusb_free_device_list(devlist, 1);
 210
 211         if (sdi && sdi->status != SR_ST_ACTIVE)
 212                 sdi = NULL;
 213
 214         return sdi;
 215 }
 216
 217 static int upload_firmware(libusb_device *dev)
 218 {
 219         int ret;
 220
 221         ret = ezusb_upload_firmware(dev, USB_CONFIGURATION, FIRMWARE);
 222         if (ret != 0)
 223                 return 1;
 224
 225         /* Remember when the last firmware update was done. */
 226         g_get_current_time(&firmware_updated);
 227
 228         return 0;
 229 }
 230
 231 static void close_device(struct sr_device_instance *sdi)
 232 {
 233         if (sdi->usb->devhdl == NULL)
 234                 return;
 235
 236         sr_info("saleae: closing device %d on %d.%d interface %d", sdi->index,
 237                 sdi->usb->bus, sdi->usb->address, USB_INTERFACE);
 238         libusb_release_interface(sdi->usb->devhdl, USB_INTERFACE);
 239         libusb_close(sdi->usb->devhdl);
 240         sdi->usb->devhdl = NULL;
 241         sdi->status = SR_ST_INACTIVE;
 242 }
 243
 244 static int configure_probes(GSList *probes)
 245 {
 246         struct sr_probe *probe;
 247         GSList *l;
 248         int probe_bit, stage, i;
 249         char *tc;
 250
 251         probe_mask = 0;
 252         for (i = 0; i < NUM_TRIGGER_STAGES; i++) {
 253                 trigger_mask[i] = 0;
 254                 trigger_value[i] = 0;
 255         }
 256
 257         stage = -1;
 258         for (l = probes; l; l = l->next) {
 259                 probe = (struct sr_probe *)l->data;
 260                 if (probe->enabled == FALSE)
 261                         continue;
 262                 probe_bit = 1 << (probe->index - 1);
 263                 probe_mask |= probe_bit;
 264                 if (!(probe->trigger))
 265                         continue;
 266
 267                 stage = 0;
 268                 for (tc = probe->trigger; *tc; tc++) {
 269                         trigger_mask[stage] |= probe_bit;
 270                         if (*tc == '1')
 271                                 trigger_value[stage] |= probe_bit;
 272                         stage++;
 273                         if (stage > NUM_TRIGGER_STAGES)
 274                                 return SR_ERR;
 275                 }
 276         }
 277
 278         if (stage == -1)
 279                 /*
 280                  * We didn't configure any triggers, make sure acquisition
 281                  * doesn't wait for any.
 282                  */
 283                 trigger_stage = TRIGGER_FIRED;
 284         else
 285                 trigger_stage = 0;
 286
 287         return SR_OK;
 288 }
 289
 290 /*
 291  * API callbacks
 292  */
 293
 294 static int hw_init(const char *deviceinfo)
 295 {
 296         struct sr_device_instance *sdi;
 297         struct libusb_device_descriptor des;
 298         libusb_device **devlist;
 299         int err, devcnt, i;
 300
 301         /* Avoid compiler warnings. */
 302         deviceinfo = deviceinfo;
 303
 304         if (libusb_init(&usb_context) != 0) {
 305                 sr_warn("Failed to initialize USB.");
 306                 return 0;
 307         }
 308
 309         /* Find all Saleae Logic devices and upload firmware to all of them. */
 310         devcnt = 0;
 311         libusb_get_device_list(usb_context, &devlist);
 312         for (i = 0; devlist[i]; i++) {
 313                 err = libusb_get_device_descriptor(devlist[i], &des);
 314                 if (err != 0) {
 315                         sr_warn("failed to get device descriptor: %d", err);
 316                         continue;
 317                 }
 318
 319                 if (des.idVendor != USB_VENDOR || des.idProduct != USB_PRODUCT)
 320                         continue; /* Not a Saleae Logic... */
 321
 322                 sdi = sr_device_instance_new(devcnt, SR_ST_INITIALIZING,
 323                         USB_VENDOR_NAME, USB_MODEL_NAME, USB_MODEL_VERSION);
 324                 if (!sdi)
 325                         return 0;
 326                 device_instances = g_slist_append(device_instances, sdi);
 327
 328                 if (check_conf_profile(devlist[i]) == 0) {
 329                         /*
 330                          * Continue on the off chance that the device is in a
 331                          * working state. TODO: Could maybe try a USB reset,
 332                          * or uploading the firmware again.
 333                          */
 334                         if (upload_firmware(devlist[i]) > 0)
 335                                 sr_warn("firmware upload failed for device %d",
 336                                         devcnt);
 337
 338                         sdi->usb = sr_usb_device_instance_new
 339                                 (libusb_get_bus_number(devlist[i]), 0, NULL);
 340                 } else {
 341                         /* Already has the firmware, so fix the new address. */
 342                         sdi->usb = sr_usb_device_instance_new
 343                             (libusb_get_bus_number(devlist[i]),
 344                              libusb_get_device_address(devlist[i]), NULL);
 345                 }
 346                 devcnt++;
 347         }
 348         libusb_free_device_list(devlist, 1);
 349
 350         return devcnt;
 351 }
 352
 353 static int hw_opendev(int device_index)
 354 {
 355         GTimeVal cur_time;
 356         struct sr_device_instance *sdi;
 357         int timediff, err;
 358         unsigned int cur, upd;
 359
 360         if (firmware_updated.tv_sec > 0) {
 361                 /* Firmware was recently uploaded. */
 362                 g_get_current_time(&cur_time);
 363                 cur = cur_time.tv_sec * 1000 + cur_time.tv_usec / 1000;
 364                 upd = firmware_updated.tv_sec * 1000 +
 365                       firmware_updated.tv_usec / 1000;
 366                 timediff = cur - upd;
 367                 if (timediff < FIRMWARE_RENUM_DELAY) {
 368                         timediff = FIRMWARE_RENUM_DELAY - timediff;
 369                         sr_info("saleae: waiting %d ms for device to reset",
 370                                 timediff);
 371                         g_usleep(timediff * 1000);
 372                         firmware_updated.tv_sec = 0;
 373                 }
 374         }
 375
 376         if (!(sdi = sl_open_device(device_index))) {
 377                 sr_warn("unable to open device");
 378                 return SR_ERR;
 379         }
 380
 381         err = libusb_claim_interface(sdi->usb->devhdl, USB_INTERFACE);
 382         if (err != 0) {
 383                 sr_warn("Unable to claim interface: %d", err);
 384                 return SR_ERR;
 385         }
 386
 387         if (cur_samplerate == 0) {
 388                 /* Samplerate hasn't been set; default to the slowest one. */
 389                 if (hw_set_configuration(device_index, SR_HWCAP_SAMPLERATE,
 390                     &supported_samplerates[0]) == SR_ERR)
 391                         return SR_ERR;
 392         }
 393
 394         return SR_OK;
 395 }
 396
 397 static void hw_closedev(int device_index)
 398 {
 399         struct sr_device_instance *sdi;
 400
 401         if ((sdi = sr_get_device_instance(device_instances, device_index)))
 402                 close_device(sdi);
 403 }
 404
 405 static void hw_cleanup(void)
 406 {
 407         GSList *l;
 408
 409         /* Properly close all devices... */
 410         for (l = device_instances; l; l = l->next)
 411                 close_device((struct sr_device_instance *)l->data);
 412
 413         /* ...and free all their memory. */
 414         for (l = device_instances; l; l = l->next)
 415                 g_free(l->data);
 416         g_slist_free(device_instances);
 417         device_instances = NULL;
 418
 419         if (usb_context)
 420                 libusb_exit(usb_context);
 421         usb_context = NULL;
 422 }
 423
 424 static void *hw_get_device_info(int device_index, int device_info_id)
 425 {
 426         struct sr_device_instance *sdi;
 427         void *info = NULL;
 428
 429         if (!(sdi = sr_get_device_instance(device_instances, device_index)))
 430                 return NULL;
 431
 432         switch (device_info_id) {
 433         case SR_DI_INSTANCE:
 434                 info = sdi;
 435                 break;
 436         case SR_DI_NUM_PROBES:
 437                 info = GINT_TO_POINTER(NUM_PROBES);
 438                 break;
 439         case SR_DI_SAMPLERATES:
 440                 info = &samplerates;
 441                 break;
 442         case SR_DI_TRIGGER_TYPES:
 443                 info = TRIGGER_TYPES;
 444                 break;
 445         case SR_DI_CUR_SAMPLERATE:
 446                 info = &cur_samplerate;
 447                 break;
 448         }
 449
 450         return info;
 451 }
 452
 453 static int hw_get_status(int device_index)
 454 {
 455         struct sr_device_instance *sdi;
 456
 457         sdi = sr_get_device_instance(device_instances, device_index);
 458         if (sdi)
 459                 return sdi->status;
 460         else
 461                 return SR_ST_NOT_FOUND;
 462 }
 463
 464 static int *hw_get_capabilities(void)
 465 {
 466         return capabilities;
 467 }
 468
 469 static int set_configuration_samplerate(struct sr_device_instance *sdi,
 470                                         uint64_t samplerate)
 471 {
 472         uint8_t divider;
 473         int ret, result, i;
 474         unsigned char buf[2];
 475
 476         for (i = 0; supported_samplerates[i]; i++) {
 477                 if (supported_samplerates[i] == samplerate)
 478                         break;
 479         }
 480         if (supported_samplerates[i] == 0)
 481                 return SR_ERR_SAMPLERATE;
 482
 483         divider = (uint8_t) (48 / (samplerate / 1000000.0)) - 1;
 484
 485         sr_info("saleae: setting samplerate to %" PRIu64 " Hz (divider %d)",
 486                 samplerate, divider);
 487         buf[0] = 0x01;
 488         buf[1] = divider;
 489         ret = libusb_bulk_transfer(sdi->usb->devhdl, 1 | LIBUSB_ENDPOINT_OUT,
 490                                    buf, 2, &result, 500);
 491         if (ret != 0) {
 492                 sr_warn("failed to set samplerate: %d", ret);
 493                 return SR_ERR;
 494         }
 495         cur_samplerate = samplerate;
 496
 497         return SR_OK;
 498 }
 499
 500 static int hw_set_configuration(int device_index, int capability, void *value)
 501 {
 502         struct sr_device_instance *sdi;
 503         int ret;
 504         uint64_t *tmp_u64;
 505
 506         if (!(sdi = sr_get_device_instance(device_instances, device_index)))
 507                 return SR_ERR;
 508
 509         if (capability == SR_HWCAP_SAMPLERATE) {
 510                 tmp_u64 = value;
 511                 ret = set_configuration_samplerate(sdi, *tmp_u64);
 512         } else if (capability == SR_HWCAP_PROBECONFIG) {
 513                 ret = configure_probes((GSList *) value);
 514         } else if (capability == SR_HWCAP_LIMIT_SAMPLES) {
 515                 tmp_u64 = value;
 516                 limit_samples = *tmp_u64;
 517                 ret = SR_OK;
 518         } else {
 519                 ret = SR_ERR;
 520         }
 521
 522         return ret;
 523 }
 524
 525 static int receive_data(int fd, int revents, void *user_data)
 526 {
 527         struct timeval tv;
 528
 529         /* Avoid compiler warnings. */
 530         fd = fd;
 531         revents = revents;
 532         user_data = user_data;
 533
 534         tv.tv_sec = tv.tv_usec = 0;
 535         libusb_handle_events_timeout(usb_context, &tv);
 536
 537         return TRUE;
 538 }
 539
 540 void receive_transfer(struct libusb_transfer *transfer)
 541 {
 542         static int num_samples = 0;
 543         static int empty_transfer_count = 0;
 544         struct sr_datafeed_packet packet;
 545         void *user_data;
 546         int cur_buflen, trigger_offset, i;
 547         unsigned char *cur_buf, *new_buf;
 548
 549         /* hw_stop_acquisition() is telling us to stop. */
 550         if (transfer == NULL)
 551                 num_samples = -1;
 552
 553         /*
 554          * If acquisition has already ended, just free any queued up
 555          * transfer that come in.
 556          */
 557         if (num_samples == -1) {
 558                 if (transfer)
 559                         libusb_free_transfer(transfer);
 560                 return;
 561         }
 562
 563         sr_info("saleae: receive_transfer(): status %d received %d bytes",
 564                 transfer->status, transfer->actual_length);
 565
 566         /* Save incoming transfer before reusing the transfer struct. */
 567         cur_buf = transfer->buffer;
 568         cur_buflen = transfer->actual_length;
 569         user_data = transfer->user_data;
 570
 571         /* Fire off a new request. */
 572         new_buf = g_malloc(4096);
 573         transfer->buffer = new_buf;
 574         transfer->length = 4096;
 575         if (libusb_submit_transfer(transfer) != 0) {
 576                 /* TODO: Stop session? */
 577                 sr_warn("eek");
 578         }
 579
 580         if (cur_buflen == 0) {
 581                 empty_transfer_count++;
 582                 if (empty_transfer_count > MAX_EMPTY_TRANSFERS) {
 583                         /*
 584                          * The FX2 gave up. End the acquisition, the frontend
 585                          * will work out that the samplecount is short.
 586                          */
 587                         hw_stop_acquisition(-1, user_data);
 588                 }
 589                 return;
 590         } else {
 591                 empty_transfer_count = 0;
 592         }
 593
 594         trigger_offset = 0;
 595         if (trigger_stage >= 0) {
 596                 for (i = 0; i < cur_buflen; i++) {
 597
 598                         if ((cur_buf[i] & trigger_mask[trigger_stage]) == trigger_value[trigger_stage]) {
 599                                 /* Match on this trigger stage. */
 600                                 trigger_buffer[trigger_stage] = cur_buf[i];
 601                                 trigger_stage++;
 602                                 if (trigger_stage == NUM_TRIGGER_STAGES || trigger_mask[trigger_stage] == 0) {
 603                                         /* Match on all trigger stages, we're done. */
 604                                         trigger_offset = i + 1;
 605
 606                                         /*
 607                                          * TODO: Send pre-trigger buffer to session bus.
 608                                          * Tell the frontend we hit the trigger here.
 609                                          */
 610                                         packet.type = SR_DF_TRIGGER;
 611                                         packet.length = 0;
 612                                         sr_session_bus(user_data, &packet);
 613
 614                                         /*
 615                                          * Send the samples that triggered it, since we're
 616                                          * skipping past them.
 617                                          */
 618                                         packet.type = SR_DF_LOGIC;
 619                                         packet.length = trigger_stage;
 620                                         packet.unitsize = 1;
 621                                         packet.payload = trigger_buffer;
 622                                         sr_session_bus(user_data, &packet);
 623
 624                                         trigger_stage = TRIGGER_FIRED;
 625                                         break;
 626                                 }
 627                                 return;
 628                         }
 629
 630                         /*
 631                          * We had a match before, but not in the next sample. However, we may
 632                          * have a match on this stage in the next bit -- trigger on 0001 will
 633                          * fail on seeing 00001, so we need to go back to stage 0 -- but at
 634                          * the next sample from the one that matched originally, which the
 635                          * counter increment at the end of the loop takes care of.
 636                          */
 637                         if (trigger_stage > 0) {
 638                                 i -= trigger_stage;
 639                                 if (i < -1)
 640                                         i = -1; /* Oops, went back past this buffer. */
 641                                 /* Reset trigger stage. */
 642                                 trigger_stage = 0;
 643                         }
 644
 645
 646                 }
 647         }
 648
 649         if (trigger_stage == TRIGGER_FIRED) {
 650                 /* Send the incoming transfer to the session bus. */
 651                 packet.type = SR_DF_LOGIC;
 652                 packet.length = cur_buflen - trigger_offset;
 653                 packet.unitsize = 1;
 654                 packet.payload = cur_buf + trigger_offset;
 655                 sr_session_bus(user_data, &packet);
 656                 g_free(cur_buf);
 657
 658                 num_samples += cur_buflen;
 659                 if (limit_samples && (unsigned int) num_samples > limit_samples) {
 660                         hw_stop_acquisition(-1, user_data);
 661                 }
 662         } else {
 663                 /*
 664                  * TODO: Buffer pre-trigger data in capture
 665                  * ratio-sized buffer.
 666                  */
 667         }
 668 }
 669
 670 static int hw_start_acquisition(int device_index, gpointer session_device_id)
 671 {
 672         struct sr_device_instance *sdi;
 673         struct sr_datafeed_packet *packet;
 674         struct sr_datafeed_header *header;
 675         struct libusb_transfer *transfer;
 676         const struct libusb_pollfd **lupfd;
 677         int size, i;
 678         unsigned char *buf;
 679
 680         if (!(sdi = sr_get_device_instance(device_instances, device_index)))
 681                 return SR_ERR;
 682
 683         packet = g_malloc(sizeof(struct sr_datafeed_packet));
 684         header = g_malloc(sizeof(struct sr_datafeed_header));
 685         if (!packet || !header)
 686                 return SR_ERR;
 687
 688         /* Start with 2K transfer, subsequently increased to 4K. */
 689         size = 2048;
 690         for (i = 0; i < NUM_SIMUL_TRANSFERS; i++) {
 691                 buf = g_malloc(size);
 692                 transfer = libusb_alloc_transfer(0);
 693                 libusb_fill_bulk_transfer(transfer, sdi->usb->devhdl,
 694                                 2 | LIBUSB_ENDPOINT_IN, buf, size,
 695                                 receive_transfer, session_device_id, 40);
 696                 if (libusb_submit_transfer(transfer) != 0) {
 697                         /* TODO: Free them all. */
 698                         libusb_free_transfer(transfer);
 699                         g_free(buf);
 700                         return SR_ERR;
 701                 }
 702                 size = 4096;
 703         }
 704
 705         lupfd = libusb_get_pollfds(usb_context);
 706         for (i = 0; lupfd[i]; i++)
 707                 sr_source_add(lupfd[i]->fd, lupfd[i]->events, 40, receive_data,
 708                               NULL);
 709         free(lupfd);
 710
 711         packet->type = SR_DF_HEADER;
 712         packet->length = sizeof(struct sr_datafeed_header);
 713         packet->payload = (unsigned char *)header;
 714         header->feed_version = 1;
 715         gettimeofday(&header->starttime, NULL);
 716         header->samplerate = cur_samplerate;
 717         header->protocol_id = SR_PROTO_RAW;
 718         header->num_logic_probes = NUM_PROBES;
 719         header->num_analog_probes = 0;
 720         sr_session_bus(session_device_id, packet);
 721         g_free(header);
 722         g_free(packet);
 723
 724         return SR_OK;
 725 }
 726
 727 /* This stops acquisition on ALL devices, ignoring device_index. */
 728 static void hw_stop_acquisition(int device_index, gpointer session_device_id)
 729 {
 730         struct sr_datafeed_packet packet;
 731
 732         /* Avoid compiler warnings. */
 733         device_index = device_index;
 734
 735         packet.type = SR_DF_END;
 736         sr_session_bus(session_device_id, &packet);
 737
 738         receive_transfer(NULL);
 739
 740         /* TODO: Need to cancel and free any queued up transfers. */
 741 }
 742
 743 struct sr_device_plugin saleae_logic_plugin_info = {
 744         "saleae-logic",
 745         "Saleae Logic",
 746         1,
 747         hw_init,
 748         hw_cleanup,
 749         hw_opendev,
 750         hw_closedev,
 751         hw_get_device_info,
 752         hw_get_status,
 753         hw_get_capabilities,
 754         hw_set_configuration,
 755         hw_start_acquisition,
 756         hw_stop_acquisition,
 757 };