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 <stdio.h>
  21 #include <stdlib.h>
  22 #include <sys/time.h>
  23 #include <inttypes.h>
  24 #include <glib.h>
  25 #include <libusb.h>
  26 #include "config.h"
  27 #include "sigrok.h"
  28
  29 #define USB_VENDOR                      0x0925
  30 #define USB_PRODUCT                     0x3881
  31 #define USB_VENDOR_NAME                 "Saleae"
  32 #define USB_MODEL_NAME                  "Logic"
  33 #define USB_MODEL_VERSION               ""
  34
  35 #define USB_INTERFACE                   0
  36 #define USB_CONFIGURATION               1
  37 #define NUM_PROBES                      8
  38 #define NUM_TRIGGER_STAGES              4
  39 #define TRIGGER_TYPES                   "01"
  40 #define FIRMWARE                        FIRMWARE_DIR "/saleae-logic.firmware"
  41
  42 /* delay in ms */
  43 #define FIRMWARE_RENUM_DELAY            2000
  44 #define NUM_SIMUL_TRANSFERS             10
  45 #define MAX_EMPTY_TRANSFERS             (NUM_SIMUL_TRANSFERS * 2)
  46
  47 /* software trigger implementation: positive values indicate trigger stage */
  48 #define TRIGGER_FIRED                   -1
  49
  50 /* There is only one model Saleae Logic, and this is what it supports: */
  51 static int capabilities[] = {
  52         HWCAP_LOGIC_ANALYZER,
  53         HWCAP_SAMPLERATE,
  54
  55         /* These are really implemented in the driver, not the hardware. */
  56         HWCAP_LIMIT_SAMPLES,
  57         0,
  58 };
  59
  60 /* List of struct sigrok_device_instance, maintained by opendev()/closedev(). */
  61 static GSList *device_instances = NULL;
  62
  63 /*
  64  * Since we can't keep track of a Saleae Logic device after upgrading the
  65  * firmware -- it re-enumerates into a different device address after the
  66  * upgrade -- this is like a global lock. No device will open until a proper
  67  * delay after the last device was upgraded.
  68  */
  69 GTimeVal firmware_updated = { 0 };
  70
  71 static libusb_context *usb_context = NULL;
  72
  73 static uint64_t supported_samplerates[] = {
  74         KHZ(200),
  75         KHZ(250),
  76         KHZ(500),
  77         MHZ(1),
  78         MHZ(2),
  79         MHZ(4),
  80         MHZ(8),
  81         MHZ(12),
  82         MHZ(16),
  83         MHZ(24),
  84         0,
  85 };
  86
  87 static struct samplerates samplerates = {
  88         KHZ(200),
  89         MHZ(24),
  90         0,
  91         supported_samplerates,
  92 };
  93
  94 /* TODO: All of these should go in a device-specific struct. */
  95 static uint64_t cur_samplerate = 0;
  96 static uint64_t limit_samples = 0;
  97 static uint8_t probe_mask = 0;
  98 static uint8_t trigger_mask[NUM_TRIGGER_STAGES] = { 0 };
  99 static uint8_t trigger_value[NUM_TRIGGER_STAGES] = { 0 };
 100 static uint8_t trigger_buffer[NUM_TRIGGER_STAGES] = { 0 };
 101 int trigger_stage = TRIGGER_FIRED;
 102
 103 static int hw_set_configuration(int device_index, int capability, void *value);
 104
 105 /* returns 1 if the device's configuration profile match the Logic firmware's
 106  * configuration, 0 otherwise
 107  */
 108 int check_conf_profile(libusb_device *dev)
 109 {
 110         struct libusb_device_descriptor des;
 111         struct libusb_config_descriptor *conf_dsc = NULL;
 112         const struct libusb_interface_descriptor *intf_dsc;
 113         int ret = -1;
 114
 115         while (ret == -1) {
 116                 /* Assume it's not a Saleae Logic unless proven wrong. */
 117                 ret = 0;
 118
 119                 if (libusb_get_device_descriptor(dev, &des) != 0)
 120                         break;
 121
 122                 if (des.bNumConfigurations != 1)
 123                         /* Need exactly 1 configuration. */
 124                         break;
 125
 126                 if (libusb_get_config_descriptor(dev, 0, &conf_dsc) != 0)
 127                         break;
 128
 129                 if (conf_dsc->bNumInterfaces != 1)
 130                         /* Need exactly 1 interface. */
 131                         break;
 132
 133                 if (conf_dsc->interface[0].num_altsetting != 1)
 134                         /* Need just one alternate setting. */
 135                         break;
 136
 137                 intf_dsc = &(conf_dsc->interface[0].altsetting[0]);
 138                 if (intf_dsc->bNumEndpoints != 2)
 139                         /* Need 2 endpoints. */
 140                         break;
 141
 142                 if ((intf_dsc->endpoint[0].bEndpointAddress & 0x8f) !=
 143                     (1 | LIBUSB_ENDPOINT_OUT))
 144                         /* First endpoint should be 1 (outbound). */
 145                         break;
 146
 147                 if ((intf_dsc->endpoint[1].bEndpointAddress & 0x8f) !=
 148                     (2 | LIBUSB_ENDPOINT_IN))
 149                         /* First endpoint should be 2 (inbound). */
 150                         break;
 151
 152                 /* If we made it here, it must be a Saleae Logic. */
 153                 ret = 1;
 154         }
 155
 156         if (conf_dsc)
 157                 libusb_free_config_descriptor(conf_dsc);
 158
 159         return ret;
 160 }
 161
 162 static int opendev2(int device_index, struct sigrok_device_instance **sdi,
 163                     libusb_device *dev, struct libusb_device_descriptor *des,
 164                     int *skip)
 165 {
 166         int err;
 167
 168         if ((err = libusb_get_device_descriptor(dev, des))) {
 169                 g_warning("failed to get device descriptor: %d", err);
 170                 return -1;
 171         }
 172
 173         if (des->idVendor != USB_VENDOR || des->idProduct != USB_PRODUCT)
 174                 return 0;
 175
 176         if (*skip != device_index) {
 177                 /* Skip devices of this type that aren't the one we want. */
 178                 *skip += 1;
 179                 return 0;
 180         }
 181
 182         /*
 183          * Should check the bus here, since we know that already. But what are
 184          * we going to do if it doesn't match after the right number of skips?
 185          */
 186         if (!(err = libusb_open(dev, &((*sdi)->usb->devhdl)))) {
 187                 (*sdi)->usb->address = libusb_get_device_address(dev);
 188                 (*sdi)->status = ST_ACTIVE;
 189                 g_message("opened device %d on %d.%d interface %d",
 190                           (*sdi)->index, (*sdi)->usb->bus,
 191                           (*sdi)->usb->address, USB_INTERFACE);
 192         } else {
 193                 g_warning("failed to open device: %d", err);
 194                 *sdi = NULL;
 195         }
 196
 197         return 0;
 198 }
 199
 200 static int opendev3(int device_index, struct sigrok_device_instance **sdi,
 201                     libusb_device *dev, struct libusb_device_descriptor *des)
 202 {
 203         int err;
 204
 205         if ((err = libusb_get_device_descriptor(dev, des))) {
 206                 g_warning("failed to get device descriptor: %d", err);
 207                 return -1;
 208         }
 209
 210         if (des->idVendor != USB_VENDOR || des->idProduct != USB_PRODUCT)
 211                 return 0;
 212
 213         if (libusb_get_bus_number(dev) == (*sdi)->usb->bus
 214             && libusb_get_device_address(dev) == (*sdi)->usb->address) {
 215                 /* Found it. */
 216                 if (!(err = libusb_open(dev, &((*sdi)->usb->devhdl)))) {
 217                         (*sdi)->status = ST_ACTIVE;
 218                         g_message("opened device %d on %d.%d interface %d",
 219                                   (*sdi)->index, (*sdi)->usb->bus,
 220                                   (*sdi)->usb->address, USB_INTERFACE);
 221                 } else {
 222                         g_warning("failed to open device: %d", err);
 223                         *sdi = NULL;
 224                 }
 225         }
 226
 227         return 0;
 228 }
 229
 230 struct sigrok_device_instance *sl_open_device(int device_index)
 231 {
 232         struct sigrok_device_instance *sdi;
 233         libusb_device **devlist;
 234         struct libusb_device_descriptor des;
 235         int err, skip, i;
 236
 237         if (!(sdi = get_sigrok_device_instance(device_instances, device_index)))
 238                 return NULL;
 239
 240         libusb_get_device_list(usb_context, &devlist);
 241         if (sdi->status == ST_INITIALIZING) {
 242                 /*
 243                  * This device was renumerating last time we touched it.
 244                  * opendev() guarantees we've waited long enough for it to
 245                  * have booted properly, so now we need to find it on
 246                  * the bus and record its new address.
 247                  */
 248                 skip = 0;
 249                 for (i = 0; devlist[i]; i++) {
 250                         /* TODO: Error handling. */
 251                         err = opendev2(device_index, &sdi, devlist[i], &des,
 252                                        &skip);
 253                 }
 254         } else if (sdi->status == ST_INACTIVE) {
 255                 /*
 256                  * This device is fully enumerated, so we need to find this
 257                  * device by vendor, product, bus and address.
 258                  */
 259                 libusb_get_device_list(usb_context, &devlist);
 260                 for (i = 0; devlist[i]; i++) {
 261                         /* TODO: Error handling. */
 262                         err = opendev3(device_index, &sdi, devlist[i], &des);
 263                 }
 264         } else {
 265                 /* Status must be ST_ACTIVE, i.e. already in use... */
 266                 sdi = NULL;
 267         }
 268         libusb_free_device_list(devlist, 1);
 269
 270         if (sdi && sdi->status != ST_ACTIVE)
 271                 sdi = NULL;
 272
 273         return sdi;
 274 }
 275
 276 int upload_firmware(libusb_device *dev)
 277 {
 278         int ret;
 279
 280         if (ret = ezusb_upload_firmware(dev, USB_CONFIGURATION, FIRMWARE) != 0)
 281                 return 1;
 282
 283         /* Remember when the last firmware update was done. */
 284         g_get_current_time(&firmware_updated);
 285
 286         return 0;
 287 }
 288
 289 static void close_device(struct sigrok_device_instance *sdi)
 290 {
 291         if (sdi->usb->devhdl == NULL)
 292                 return;
 293
 294         g_message("closing device %d on %d.%d interface %d", sdi->index,
 295                   sdi->usb->bus, sdi->usb->address, USB_INTERFACE);
 296         libusb_release_interface(sdi->usb->devhdl, USB_INTERFACE);
 297         libusb_close(sdi->usb->devhdl);
 298         sdi->usb->devhdl = NULL;
 299         sdi->status = ST_INACTIVE;
 300 }
 301
 302 static int configure_probes(GSList * probes)
 303 {
 304         struct probe *probe;
 305         GSList *l;
 306         int probe_bit, stage, i;
 307         char *tc;
 308
 309         probe_mask = 0;
 310         for (i = 0; i < NUM_TRIGGER_STAGES; i++) {
 311                 trigger_mask[i] = 0;
 312                 trigger_value[i] = 0;
 313         }
 314
 315         stage = -1;
 316         for (l = probes; l; l = l->next) {
 317                 probe = (struct probe *)l->data;
 318                 if (probe->enabled == FALSE)
 319                         continue;
 320                 probe_bit = 1 << (probe->index - 1);
 321                 probe_mask |= probe_bit;
 322                 if (probe->trigger) {
 323                         stage = 0;
 324                         for (tc = probe->trigger; *tc; tc++) {
 325                                 trigger_mask[stage] |= probe_bit;
 326                                 if (*tc == '1')
 327                                         trigger_value[stage] |= probe_bit;
 328                                 stage++;
 329                                 if (stage > NUM_TRIGGER_STAGES)
 330                                         return SIGROK_ERR;
 331                         }
 332                 }
 333         }
 334
 335         if (stage == -1)
 336                 /*
 337                  * We didn't configure any triggers, make sure acquisition
 338                  * doesn't wait for any.
 339                  */
 340                 trigger_stage = TRIGGER_FIRED;
 341         else
 342                 trigger_stage = 0;
 343
 344         return SIGROK_OK;
 345 }
 346
 347 /*
 348  * API callbacks
 349  */
 350
 351 static int hw_init(char *deviceinfo)
 352 {
 353         struct sigrok_device_instance *sdi;
 354         struct libusb_device_descriptor des;
 355         libusb_device **devlist;
 356         int err, devcnt, i;
 357
 358         if (libusb_init(&usb_context) != 0) {
 359                 g_warning("Failed to initialize USB.");
 360                 return 0;
 361         }
 362         libusb_set_debug(usb_context, 3);
 363
 364         /* Find all Saleae Logic devices and upload firmware to all of them. */
 365         devcnt = 0;
 366         libusb_get_device_list(usb_context, &devlist);
 367         for (i = 0; devlist[i]; i++) {
 368                 err = libusb_get_device_descriptor(devlist[i], &des);
 369                 if (err != 0) {
 370                         g_warning("failed to get device descriptor: %d", err);
 371                         continue;
 372                 }
 373
 374                 if (des.idVendor != USB_VENDOR || des.idProduct != USB_PRODUCT)
 375                         continue; /* Not a Saleae Logic... */
 376
 377                 sdi = sigrok_device_instance_new(devcnt, ST_INITIALIZING,
 378                         USB_VENDOR_NAME, USB_MODEL_NAME, USB_MODEL_VERSION);
 379                 if (!sdi)
 380                         return 0;
 381                 device_instances = g_slist_append(device_instances, sdi);
 382
 383                 if (check_conf_profile(devlist[i]) == 0) {
 384                         /*
 385                          * Continue on the off chance that the device is in a
 386                          * working state. TODO: Could maybe try a USB reset,
 387                          * or uploading the firmware again.
 388                          */
 389                         if (upload_firmware(devlist[i]) > 0)
 390                                 g_warning("firmware upload failed for device %d", devcnt);
 391
 392                         sdi->usb = usb_device_instance_new
 393                           (libusb_get_bus_number(devlist[i]), 0, NULL);
 394                 } else {
 395                         /* Already has the firmware, so fix the new address. */
 396                         sdi->usb = usb_device_instance_new
 397                             (libusb_get_bus_number(devlist[i]),
 398                              libusb_get_device_address(devlist[i]),
 399                              NULL);
 400                 }
 401                 devcnt++;
 402         }
 403         libusb_free_device_list(devlist, 1);
 404
 405         return devcnt;
 406 }
 407
 408 static int hw_opendev(int device_index)
 409 {
 410         GTimeVal cur_time;
 411         struct sigrok_device_instance *sdi;
 412         int timediff, err;
 413         unsigned int cur, upd;
 414
 415         if (firmware_updated.tv_sec > 0) {
 416                 /* Firmware was recently uploaded. */
 417                 g_get_current_time(&cur_time);
 418                 cur = cur_time.tv_sec * 1000 + cur_time.tv_usec / 1000;
 419                 upd = firmware_updated.tv_sec * 1000 +
 420                       firmware_updated.tv_usec / 1000;
 421                 timediff = cur - upd;
 422                 if (timediff < FIRMWARE_RENUM_DELAY) {
 423                         timediff = FIRMWARE_RENUM_DELAY - timediff;
 424                         g_message("waiting %d ms for device to reset",
 425                                   timediff);
 426                         g_usleep(timediff * 1000);
 427                         firmware_updated.tv_sec = 0;
 428                 }
 429         }
 430
 431         if (!(sdi = sl_open_device(device_index))) {
 432                 g_warning("unable to open device");
 433                 return SIGROK_ERR;
 434         }
 435
 436         err = libusb_claim_interface(sdi->usb->devhdl, USB_INTERFACE);
 437         if (err != 0) {
 438                 g_warning("Unable to claim interface: %d", err);
 439                 return SIGROK_ERR;
 440         }
 441
 442         if (cur_samplerate == 0) {
 443                 /* Samplerate hasn't been set; default to the slowest one. */
 444                 if (hw_set_configuration(device_index, HWCAP_SAMPLERATE,
 445                      &supported_samplerates[0]) == SIGROK_ERR)
 446                         return SIGROK_ERR;
 447         }
 448
 449         return SIGROK_OK;
 450 }
 451
 452 static void hw_closedev(int device_index)
 453 {
 454         struct sigrok_device_instance *sdi;
 455
 456         if ((sdi = get_sigrok_device_instance(device_instances, device_index)))
 457                 close_device(sdi);
 458 }
 459
 460 static void hw_cleanup(void)
 461 {
 462         GSList *l;
 463
 464         /* Properly close all devices... */
 465         for (l = device_instances; l; l = l->next)
 466                 close_device((struct sigrok_device_instance *)l->data);
 467
 468         /* ...and free all their memory. */
 469         for (l = device_instances; l; l = l->next)
 470                 g_free(l->data);
 471         g_slist_free(device_instances);
 472         device_instances = NULL;
 473
 474         if (usb_context)
 475                 libusb_exit(usb_context);
 476         usb_context = NULL;
 477 }
 478
 479 static void *hw_get_device_info(int device_index, int device_info_id)
 480 {
 481         struct sigrok_device_instance *sdi;
 482         void *info = NULL;
 483
 484         if (!(sdi = get_sigrok_device_instance(device_instances, device_index)))
 485                 return NULL;
 486
 487         switch (device_info_id) {
 488         case DI_INSTANCE:
 489                 info = sdi;
 490                 break;
 491         case DI_NUM_PROBES:
 492                 info = GINT_TO_POINTER(NUM_PROBES);
 493                 break;
 494         case DI_SAMPLERATES:
 495                 info = &samplerates;
 496                 break;
 497         case DI_TRIGGER_TYPES:
 498                 info = TRIGGER_TYPES;
 499                 break;
 500         case DI_CUR_SAMPLERATE:
 501                 info = &cur_samplerate;
 502                 break;
 503         }
 504
 505         return info;
 506 }
 507
 508 static int hw_get_status(int device_index)
 509 {
 510         struct sigrok_device_instance *sdi;
 511
 512         sdi = get_sigrok_device_instance(device_instances, device_index);
 513         if (sdi)
 514                 return sdi->status;
 515         else
 516                 return ST_NOT_FOUND;
 517 }
 518
 519 static int *hw_get_capabilities(void)
 520 {
 521         return capabilities;
 522 }
 523
 524 static int set_configuration_samplerate(struct sigrok_device_instance *sdi,
 525                                         uint64_t samplerate)
 526 {
 527         uint8_t divider;
 528         int ret, result, i;
 529         unsigned char buf[2];
 530
 531         for (i = 0; supported_samplerates[i]; i++) {
 532                 if (supported_samplerates[i] == samplerate)
 533                         break;
 534         }
 535         if (supported_samplerates[i] == 0)
 536                 return SIGROK_ERR_SAMPLERATE;
 537
 538         divider = (uint8_t) (48 / (float)(samplerate / 1000000)) - 1;
 539
 540         g_message("setting samplerate to %" PRIu64 " Hz (divider %d)",
 541                   samplerate, divider);
 542         buf[0] = 0x01;
 543         buf[1] = divider;
 544         ret = libusb_bulk_transfer(sdi->usb->devhdl, 1 | LIBUSB_ENDPOINT_OUT,
 545                                    buf, 2, &result, 500);
 546         if (ret != 0) {
 547                 g_warning("failed to set samplerate: %d", ret);
 548                 return SIGROK_ERR;
 549         }
 550         cur_samplerate = samplerate;
 551
 552         return SIGROK_OK;
 553 }
 554
 555 static int hw_set_configuration(int device_index, int capability, void *value)
 556 {
 557         struct sigrok_device_instance *sdi;
 558         int ret;
 559         uint64_t *tmp_u64;
 560
 561         if (!(sdi = get_sigrok_device_instance(device_instances, device_index)))
 562                 return SIGROK_ERR;
 563
 564         if (capability == HWCAP_SAMPLERATE) {
 565                 tmp_u64 = value;
 566                 ret = set_configuration_samplerate(sdi, *tmp_u64);
 567         } else if (capability == HWCAP_PROBECONFIG) {
 568                 ret = configure_probes((GSList *) value);
 569         } else if (capability == HWCAP_LIMIT_SAMPLES) {
 570                 limit_samples = strtoull(value, NULL, 10);
 571                 ret = SIGROK_OK;
 572         } else {
 573                 ret = SIGROK_ERR;
 574         }
 575
 576         return ret;
 577 }
 578
 579 static int receive_data(int fd, int revents, void *user_data)
 580 {
 581         struct timeval tv;
 582
 583         tv.tv_sec = tv.tv_usec = 0;
 584         libusb_handle_events_timeout(usb_context, &tv);
 585
 586         return TRUE;
 587 }
 588
 589 void receive_transfer(struct libusb_transfer *transfer)
 590 {
 591         static int num_samples = 0;
 592         static int empty_transfer_count = 0;
 593         struct datafeed_packet packet;
 594         void *user_data;
 595         int cur_buflen, trigger_offset, i;
 596         unsigned char *cur_buf, *new_buf;
 597
 598         /* hw_stop_acquisition() is telling us to stop. */
 599         if (transfer == NULL)
 600                 num_samples = -1;
 601
 602         /*
 603          * If acquisition has already ended, just free any queued up
 604          * transfer that come in.
 605          */
 606         if (num_samples == -1) {
 607                 libusb_free_transfer(transfer);
 608                 return;
 609         }
 610
 611         g_message("receive_transfer(): status %d received %d bytes",
 612                   transfer->status, transfer->actual_length);
 613
 614         /* Save incoming transfer before reusing the transfer struct. */
 615         cur_buf = transfer->buffer;
 616         cur_buflen = transfer->actual_length;
 617         user_data = transfer->user_data;
 618
 619         /* Fire off a new request. */
 620         new_buf = g_malloc(4096);
 621         transfer->buffer = new_buf;
 622         transfer->length = 4096;
 623         if (libusb_submit_transfer(transfer) != 0) {
 624                 /* TODO: Stop session? */
 625                 g_warning("eek");
 626         }
 627
 628         if (cur_buflen == 0) {
 629                 empty_transfer_count++;
 630                 if (empty_transfer_count > MAX_EMPTY_TRANSFERS) {
 631                         /*
 632                          * The FX2 gave up. End the acquisition, the frontend
 633                          * will work out that the samplecount is short.
 634                          */
 635                         packet.type = DF_END;
 636                         session_bus(user_data, &packet);
 637                         num_samples = -1;
 638                 }
 639                 return;
 640         } else {
 641                 empty_transfer_count = 0;
 642         }
 643
 644         trigger_offset = 0;
 645         if (trigger_stage >= 0) {
 646                 for (i = 0; i < cur_buflen; i++) {
 647                         if ((cur_buf[i] & trigger_mask[trigger_stage])
 648                             == trigger_value[trigger_stage]) {
 649                                 /* Match on this trigger stage. */
 650                                 trigger_buffer[trigger_stage] = cur_buf[i];
 651                                 trigger_stage++;
 652                                 if (trigger_stage == NUM_TRIGGER_STAGES
 653                                     || trigger_mask[trigger_stage] == 0) {
 654                                         /* Match on all trigger stages, we're done */
 655                                         trigger_offset = i + 1;
 656
 657                                         /* TODO: Send pre-trigger buffer to session bus. Tell the frontend we hit the trigger here. */
 658                                         packet.type = DF_TRIGGER;
 659                                         packet.length = 0;
 660                                         session_bus(user_data, &packet);
 661
 662                                         /* Send the samples that triggered it, since we're skipping past them. */
 663                                         packet.type = DF_LOGIC8;
 664                                         packet.length = trigger_stage;
 665                                         packet.payload = trigger_buffer;
 666                                         session_bus(user_data, &packet);
 667                                         break;
 668
 669                                         trigger_stage = TRIGGER_FIRED;
 670                                 }
 671                         } else if (trigger_stage > 0) {
 672                                 /*
 673                                  * We had a match before, but not in the next sample. However, we may
 674                                  * have a match on this stage in the next bit -- trigger on 0001 will
 675                                  * fail on seeing 00001, so we need to go back to stage 0 -- but at
 676                                  * the next sample from the one that matched originally, which the
 677                                  * counter increment at the end of the loop takes care of.
 678                                  */
 679                                 i -= trigger_stage;
 680                                 if (i < -1)
 681                                         /* Oops, went back past this buffer. */
 682                                         i = -1;
 683                                 /* Reset trigger stage. */
 684                                 trigger_stage = 0;
 685                         }
 686                 }
 687         }
 688
 689         if (trigger_stage == TRIGGER_FIRED) {
 690                 /* Send the incoming transfer to the session bus. */
 691                 packet.type = DF_LOGIC8;
 692                 packet.length = cur_buflen - trigger_offset;
 693                 packet.payload = cur_buf + trigger_offset;
 694                 session_bus(user_data, &packet);
 695                 g_free(cur_buf);
 696
 697                 num_samples += cur_buflen;
 698                 if (num_samples > limit_samples) {
 699                         /* End the acquisition. */
 700                         packet.type = DF_END;
 701                         session_bus(user_data, &packet);
 702                         num_samples = -1;
 703                 }
 704         } else {
 705                 /*
 706                  * TODO: Buffer pre-trigger data in capture
 707                  * ratio-sized buffer.
 708                  */
 709         }
 710 }
 711
 712 static int hw_start_acquisition(int device_index, gpointer session_device_id)
 713 {
 714         struct sigrok_device_instance *sdi;
 715         struct datafeed_packet *packet;
 716         struct datafeed_header *header;
 717         struct libusb_transfer *transfer;
 718         const struct libusb_pollfd **lupfd;
 719         int size, i;
 720         unsigned char *buf;
 721
 722         if (!(sdi = get_sigrok_device_instance(device_instances, device_index)))
 723                 return SIGROK_ERR;
 724
 725         packet = g_malloc(sizeof(struct datafeed_packet));
 726         header = g_malloc(sizeof(struct datafeed_header));
 727         if (!packet || !header)
 728                 return SIGROK_ERR;
 729
 730         /* Start with 2K transfer, subsequently increased to 4K. */
 731         size = 2048;
 732         for (i = 0; i < NUM_SIMUL_TRANSFERS; i++) {
 733                 buf = g_malloc(size);
 734                 transfer = libusb_alloc_transfer(0);
 735                 libusb_fill_bulk_transfer(transfer, sdi->usb->devhdl,
 736                                 2 | LIBUSB_ENDPOINT_IN, buf, size,
 737                                 receive_transfer, session_device_id, 40);
 738                 if (libusb_submit_transfer(transfer) != 0) {
 739                         /* TODO: Free them all. */
 740                         libusb_free_transfer(transfer);
 741                         g_free(buf);
 742                         return SIGROK_ERR;
 743                 }
 744                 size = 4096;
 745         }
 746
 747         lupfd = libusb_get_pollfds(usb_context);
 748         for (i = 0; lupfd[i]; i++)
 749                 source_add(lupfd[i]->fd, lupfd[i]->events, -1, receive_data,
 750                            NULL);
 751         free(lupfd);
 752
 753         packet->type = DF_HEADER;
 754         packet->length = sizeof(struct datafeed_header);
 755         packet->payload = (unsigned char *)header;
 756         header->feed_version = 1;
 757         gettimeofday(&header->starttime, NULL);
 758         header->samplerate = cur_samplerate;
 759         header->protocol_id = PROTO_RAW;
 760         header->num_probes = NUM_PROBES;
 761         session_bus(session_device_id, packet);
 762         g_free(header);
 763         g_free(packet);
 764
 765         return SIGROK_OK;
 766 }
 767
 768 /* This stops acquisition on ALL devices, ignoring device_index. */
 769 static void hw_stop_acquisition(int device_index, gpointer session_device_id)
 770 {
 771         struct datafeed_packet packet;
 772
 773         packet.type = DF_END;
 774         session_bus(session_device_id, &packet);
 775
 776         receive_transfer(NULL);
 777
 778         /* TODO: Need to cancel and free any queued up transfers. */
 779 }
 780
 781 struct device_plugin saleae_logic_plugin_info = {
 782         "saleae-logic",
 783         1,
 784         hw_init,
 785         hw_cleanup,
 786
 787         hw_opendev,
 788         hw_closedev,
 789         hw_get_device_info,
 790         hw_get_status,
 791         hw_get_capabilities,
 792         hw_set_configuration,
 793         hw_start_acquisition,
 794         hw_stop_acquisition,
 795 };