src/hardware/openbench-logic-sniffer/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2013 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 "protocol.h"
  22
  23 struct ols_basic_trigger_desc {
  24         uint32_t trigger_mask[NUM_BASIC_TRIGGER_STAGES];
  25         uint32_t trigger_value[NUM_BASIC_TRIGGER_STAGES];
  26         int num_stages;
  27 };
  28
  29 SR_PRIV int send_shortcommand(struct sr_serial_dev_inst *serial,
  30                               uint8_t command)
  31 {
  32         char buf[1];
  33
  34         sr_dbg("Sending cmd 0x%.2x.", command);
  35         buf[0] = command;
  36         if (serial_write_blocking(serial, buf, 1, serial_timeout(serial, 1)) != 1)
  37                 return SR_ERR;
  38
  39         if (serial_drain(serial) != SR_OK)
  40                 return SR_ERR;
  41
  42         return SR_OK;
  43 }
  44
  45 SR_PRIV int send_longcommand(struct sr_serial_dev_inst *serial, uint8_t command,
  46                              uint8_t *data)
  47 {
  48         char buf[5];
  49
  50         sr_dbg("Sending cmd 0x%.2x data 0x%.2x%.2x%.2x%.2x.", command, data[0],
  51                data[1], data[2], data[3]);
  52         buf[0] = command;
  53         buf[1] = data[0];
  54         buf[2] = data[1];
  55         buf[3] = data[2];
  56         buf[4] = data[3];
  57         if (serial_write_blocking(serial, buf, 5, serial_timeout(serial, 1)) != 5)
  58                 return SR_ERR;
  59
  60         if (serial_drain(serial) != SR_OK)
  61                 return SR_ERR;
  62
  63         return SR_OK;
  64 }
  65
  66 static int ols_send_longdata(struct sr_serial_dev_inst *serial, uint8_t command,
  67                              uint32_t value)
  68 {
  69         uint8_t data[4];
  70         WL32(data, value);
  71         return send_longcommand(serial, command, data);
  72 }
  73
  74 SR_PRIV int ols_send_reset(struct sr_serial_dev_inst *serial)
  75 {
  76         unsigned int i;
  77
  78         for (i = 0; i < 5; i++) {
  79                 if (send_shortcommand(serial, CMD_RESET) != SR_OK)
  80                         return SR_ERR;
  81         }
  82
  83         return SR_OK;
  84 }
  85
  86 /* Configures the channel mask based on which channels are enabled. */
  87 SR_PRIV uint32_t ols_channel_mask(const struct sr_dev_inst *sdi)
  88 {
  89         uint32_t channel_mask = 0;
  90         for (const GSList *l = sdi->channels; l; l = l->next) {
  91                 struct sr_channel *channel = l->data;
  92                 if (channel->enabled)
  93                         channel_mask |= 1 << channel->index;
  94         }
  95
  96         return channel_mask;
  97 }
  98
  99 static int convert_trigger(const struct sr_dev_inst *sdi,
 100                            struct ols_basic_trigger_desc *ols_trigger)
 101 {
 102         struct sr_trigger *trigger;
 103         struct sr_trigger_stage *stage;
 104         struct sr_trigger_match *match;
 105         const GSList *l, *m;
 106         int i;
 107
 108         ols_trigger->num_stages = 0;
 109         for (i = 0; i < NUM_BASIC_TRIGGER_STAGES; i++) {
 110                 ols_trigger->trigger_mask[i] = 0;
 111                 ols_trigger->trigger_value[i] = 0;
 112         }
 113
 114         if (!(trigger = sr_session_trigger_get(sdi->session)))
 115                 return SR_OK;
 116
 117         ols_trigger->num_stages = g_slist_length(trigger->stages);
 118         if (ols_trigger->num_stages > NUM_BASIC_TRIGGER_STAGES) {
 119                 sr_err("This device only supports %d trigger stages.",
 120                        NUM_BASIC_TRIGGER_STAGES);
 121                 return SR_ERR;
 122         }
 123
 124         for (l = trigger->stages; l; l = l->next) {
 125                 stage = l->data;
 126                 for (m = stage->matches; m; m = m->next) {
 127                         match = m->data;
 128                         if (!match->channel->enabled)
 129                                 /* Ignore disabled channels with a trigger. */
 130                                 continue;
 131                         ols_trigger->trigger_mask[stage->stage] |=
 132                                 1 << match->channel->index;
 133                         if (match->match == SR_TRIGGER_ONE)
 134                                 ols_trigger->trigger_value[stage->stage] |=
 135                                         1 << match->channel->index;
 136                 }
 137         }
 138
 139         return SR_OK;
 140 }
 141
 142 SR_PRIV struct dev_context *ols_dev_new(void)
 143 {
 144         struct dev_context *devc;
 145
 146         devc = g_malloc0(sizeof(struct dev_context));
 147         devc->trigger_at_smpl = OLS_NO_TRIGGER;
 148
 149         return devc;
 150 }
 151
 152 static void ols_channel_new(struct sr_dev_inst *sdi, int num_chan)
 153 {
 154         struct dev_context *devc = sdi->priv;
 155         int i;
 156
 157         for (i = 0; i < num_chan; i++)
 158                 sr_channel_new(sdi, i, SR_CHANNEL_LOGIC, TRUE,
 159                                ols_channel_names[i]);
 160
 161         devc->max_channels = num_chan;
 162 }
 163
 164 static void ols_metadata_quirks(struct sr_dev_inst *sdi)
 165 {
 166         struct dev_context *devc;
 167         gboolean is_shrimp;
 168
 169         if (!sdi)
 170                 return;
 171         devc = sdi->priv;
 172         if (!devc)
 173                 return;
 174
 175         is_shrimp = sdi->model && strcmp(sdi->model, "Shrimp1.0") == 0;
 176         if (is_shrimp) {
 177                 if (!devc->max_channels)
 178                         ols_channel_new(sdi, 4);
 179                 if (!devc->max_samples)
 180                         devc->max_samples = 256 * 1024;
 181                 if (!devc->max_samplerate)
 182                         devc->max_samplerate = SR_MHZ(20);
 183         }
 184
 185         if (sdi->version && strstr(sdi->version, "FPGA version 3.07"))
 186                 devc->device_flags |= DEVICE_FLAG_IS_DEMON_CORE;
 187 }
 188
 189 SR_PRIV struct sr_dev_inst *get_metadata(struct sr_serial_dev_inst *serial)
 190 {
 191         struct sr_dev_inst *sdi;
 192         struct dev_context *devc;
 193         uint32_t tmp_int;
 194         uint8_t key, type;
 195         int delay_ms;
 196         GString *tmp_str, *devname, *version;
 197         guchar tmp_c;
 198
 199         sdi = g_malloc0(sizeof(struct sr_dev_inst));
 200         sdi->status = SR_ST_INACTIVE;
 201         devc = ols_dev_new();
 202         sdi->priv = devc;
 203
 204         devname = g_string_new("");
 205         version = g_string_new("");
 206
 207         key = 0xff;
 208         while (key) {
 209                 delay_ms = serial_timeout(serial, 1);
 210                 if (serial_read_blocking(serial, &key, 1, delay_ms) != 1)
 211                         break;
 212                 if (key == METADATA_TOKEN_END) {
 213                         sr_dbg("Got metadata key 0x00, metadata ends.");
 214                         break;
 215                 }
 216                 type = key >> 5;
 217                 switch (type) {
 218                 case 0:
 219                         /* NULL-terminated string */
 220                         tmp_str = g_string_new("");
 221                         delay_ms = serial_timeout(serial, 1);
 222                         while (serial_read_blocking(serial, &tmp_c, 1,
 223                                                     delay_ms) == 1 &&
 224                                tmp_c != '\0')
 225                                 g_string_append_c(tmp_str, tmp_c);
 226                         sr_dbg("Got metadata token 0x%.2x value '%s'.", key,
 227                                tmp_str->str);
 228                         switch (key) {
 229                         case METADATA_TOKEN_DEVICE_NAME:
 230                                 /* Device name */
 231                                 devname =
 232                                         g_string_append(devname, tmp_str->str);
 233                                 break;
 234                         case METADATA_TOKEN_FPGA_VERSION:
 235                                 /* FPGA firmware version */
 236                                 if (version->len)
 237                                         g_string_append(version, ", ");
 238                                 g_string_append(version, "FPGA version ");
 239                                 g_string_append(version, tmp_str->str);
 240                                 break;
 241                         case METADATA_TOKEN_ANCILLARY_VERSION:
 242                                 /* Ancillary version */
 243                                 if (version->len)
 244                                         g_string_append(version, ", ");
 245                                 g_string_append(version, "Ancillary version ");
 246                                 g_string_append(version, tmp_str->str);
 247                                 break;
 248                         default:
 249                                 sr_info("ols: unknown token 0x%.2x: '%s'", key,
 250                                         tmp_str->str);
 251                                 break;
 252                         }
 253                         g_string_free(tmp_str, TRUE);
 254                         break;
 255                 case 1:
 256                         /* 32-bit unsigned integer */
 257                         delay_ms = serial_timeout(serial, 4);
 258                         if (serial_read_blocking(serial, &tmp_int, 4,
 259                                                  delay_ms) != 4)
 260                                 break;
 261                         tmp_int = RB32(&tmp_int);
 262                         sr_dbg("Got metadata token 0x%.2x value 0x%.8x.", key,
 263                                tmp_int);
 264                         switch (key) {
 265                         case METADATA_TOKEN_NUM_PROBES_LONG:
 266                                 /* Number of usable channels */
 267                                 ols_channel_new(sdi, tmp_int);
 268                                 break;
 269                         case METADATA_TOKEN_SAMPLE_MEMORY_BYTES:
 270                                 /* Amount of sample memory available (bytes) */
 271                                 devc->max_samples = tmp_int;
 272                                 break;
 273                         case METADATA_TOKEN_DYNAMIC_MEMORY_BYTES:
 274                                 /* Amount of dynamic memory available (bytes) */
 275                                 /* what is this for? */
 276                                 break;
 277                         case METADATA_TOKEN_MAX_SAMPLE_RATE_HZ:
 278                                 /* Maximum sample rate (Hz) */
 279                                 devc->max_samplerate = tmp_int;
 280                                 break;
 281                         case METADATA_TOKEN_PROTOCOL_VERSION_LONG:
 282                                 /* protocol version */
 283                                 devc->protocol_version = tmp_int;
 284                                 break;
 285                         default:
 286                                 sr_info("Unknown token 0x%.2x: 0x%.8x.", key,
 287                                         tmp_int);
 288                                 break;
 289                         }
 290                         break;
 291                 case 2:
 292                         /* 8-bit unsigned integer */
 293                         delay_ms = serial_timeout(serial, 1);
 294                         if (serial_read_blocking(serial, &tmp_c, 1, delay_ms) != 1)
 295                                 break;
 296                         sr_dbg("Got metadata token 0x%.2x value 0x%.2x.", key,
 297                                tmp_c);
 298                         switch (key) {
 299                         case METADATA_TOKEN_NUM_PROBES_SHORT:
 300                                 /* Number of usable channels */
 301                                 ols_channel_new(sdi, tmp_c);
 302                                 break;
 303                         case METADATA_TOKEN_PROTOCOL_VERSION_SHORT:
 304                                 /* protocol version */
 305                                 devc->protocol_version = tmp_c;
 306                                 break;
 307                         default:
 308                                 sr_info("Unknown token 0x%.2x: 0x%.2x.", key,
 309                                         tmp_c);
 310                                 break;
 311                         }
 312                         break;
 313                 default:
 314                         /* unknown type */
 315                         break;
 316                 }
 317         }
 318
 319         sdi->model = devname->str;
 320         sdi->version = version->str;
 321         g_string_free(devname, FALSE);
 322         g_string_free(version, FALSE);
 323
 324         /* Optionally amend received metadata, model specific quirks. */
 325         ols_metadata_quirks(sdi);
 326
 327         return sdi;
 328 }
 329
 330 SR_PRIV int ols_set_samplerate(const struct sr_dev_inst *sdi,
 331                                const uint64_t samplerate)
 332 {
 333         struct dev_context *devc;
 334
 335         devc = sdi->priv;
 336         if (devc->max_samplerate && samplerate > devc->max_samplerate)
 337                 return SR_ERR_SAMPLERATE;
 338
 339         if (samplerate > CLOCK_RATE) {
 340                 sr_info("Enabling demux mode.");
 341                 devc->capture_flags |= CAPTURE_FLAG_DEMUX;
 342                 devc->capture_flags &= ~CAPTURE_FLAG_NOISE_FILTER;
 343                 devc->cur_samplerate_divider =
 344                         (CLOCK_RATE * 2 / samplerate) - 1;
 345         } else {
 346                 sr_info("Disabling demux mode.");
 347                 devc->capture_flags &= ~CAPTURE_FLAG_DEMUX;
 348                 devc->capture_flags |= CAPTURE_FLAG_NOISE_FILTER;
 349                 devc->cur_samplerate_divider = (CLOCK_RATE / samplerate) - 1;
 350         }
 351
 352         /* Calculate actual samplerate used and complain if it is different
 353          * from the requested.
 354          */
 355         devc->cur_samplerate = CLOCK_RATE / (devc->cur_samplerate_divider + 1);
 356         if (devc->capture_flags & CAPTURE_FLAG_DEMUX)
 357                 devc->cur_samplerate *= 2;
 358         if (devc->cur_samplerate != samplerate)
 359                 sr_info("Can't match samplerate %" PRIu64 ", using %" PRIu64
 360                         ".",
 361                         samplerate, devc->cur_samplerate);
 362
 363         return SR_OK;
 364 }
 365
 366 SR_PRIV void abort_acquisition(const struct sr_dev_inst *sdi)
 367 {
 368         struct sr_serial_dev_inst *serial;
 369
 370         serial = sdi->conn;
 371         ols_send_reset(serial);
 372
 373         serial_source_remove(sdi->session, serial);
 374
 375         std_session_send_df_end(sdi);
 376 }
 377
 378 SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 379 {
 380         struct dev_context *devc;
 381         struct sr_dev_inst *sdi;
 382         struct sr_serial_dev_inst *serial;
 383         struct sr_datafeed_packet packet;
 384         struct sr_datafeed_logic logic;
 385         uint32_t sample;
 386         int num_changroups, offset, j;
 387         unsigned int i;
 388         unsigned char byte;
 389
 390         (void)fd;
 391
 392         sdi = cb_data;
 393         serial = sdi->conn;
 394         devc = sdi->priv;
 395
 396         if (devc->num_transfers == 0 && revents == 0) {
 397                 /* Ignore timeouts as long as we haven't received anything */
 398                 return TRUE;
 399         }
 400
 401         if (devc->num_transfers++ == 0) {
 402                 devc->raw_sample_buf = g_try_malloc(devc->limit_samples * 4);
 403                 if (!devc->raw_sample_buf) {
 404                         sr_err("Sample buffer malloc failed.");
 405                         return FALSE;
 406                 }
 407                 /* fill with 1010... for debugging */
 408                 memset(devc->raw_sample_buf, 0x82, devc->limit_samples * 4);
 409         }
 410
 411         num_changroups = 0;
 412         for (i = 0x20; i > 0x02; i >>= 1) {
 413                 if ((devc->capture_flags & i) == 0) {
 414                         num_changroups++;
 415                 }
 416         }
 417
 418         if (revents == G_IO_IN && devc->num_samples < devc->limit_samples) {
 419                 if (serial_read_nonblocking(serial, &byte, 1) != 1)
 420                         return FALSE;
 421                 devc->cnt_bytes++;
 422
 423                 /* Ignore it if we've read enough. */
 424                 if (devc->num_samples >= devc->limit_samples)
 425                         return TRUE;
 426
 427                 devc->sample[devc->num_bytes++] = byte;
 428                 sr_spew("Received byte 0x%.2x.", byte);
 429                 if (devc->num_bytes == num_changroups) {
 430                         devc->cnt_samples++;
 431                         devc->cnt_samples_rle++;
 432                         /*
 433                          * Got a full sample. Convert from the OLS's little-endian
 434                          * sample to the local format.
 435                          */
 436                         sample = devc->sample[0] | (devc->sample[1] << 8) |
 437                                  (devc->sample[2] << 16) |
 438                                  (devc->sample[3] << 24);
 439                         sr_dbg("Received sample 0x%.*x.", devc->num_bytes * 2,
 440                                sample);
 441                         if (devc->capture_flags & CAPTURE_FLAG_RLE) {
 442                                 /*
 443                                  * In RLE mode the high bit of the sample is the
 444                                  * "count" flag, meaning this sample is the number
 445                                  * of times the previous sample occurred.
 446                                  */
 447                                 if (devc->sample[devc->num_bytes - 1] & 0x80) {
 448                                         /* Clear the high bit. */
 449                                         sample &= ~(0x80 << (devc->num_bytes -
 450                                                              1) * 8);
 451                                         devc->rle_count = sample;
 452                                         devc->cnt_samples_rle +=
 453                                                 devc->rle_count;
 454                                         sr_dbg("RLE count: %u.",
 455                                                devc->rle_count);
 456                                         devc->num_bytes = 0;
 457                                         return TRUE;
 458                                 }
 459                         }
 460                         devc->num_samples += devc->rle_count + 1;
 461                         if (devc->num_samples > devc->limit_samples) {
 462                                 /* Save us from overrunning the buffer. */
 463                                 devc->rle_count -=
 464                                         devc->num_samples - devc->limit_samples;
 465                                 devc->num_samples = devc->limit_samples;
 466                         }
 467
 468                         if (num_changroups < 4) {
 469                                 /*
 470                                  * Some channel groups may have been turned
 471                                  * off, to speed up transfer between the
 472                                  * hardware and the PC. Expand that here before
 473                                  * submitting it over the session bus --
 474                                  * whatever is listening on the bus will be
 475                                  * expecting a full 32-bit sample, based on
 476                                  * the number of channels.
 477                                  */
 478                                 j = 0;
 479                                 uint8_t tmp_sample[4] = { 0, 0, 0, 0 };
 480                                 for (i = 0; i < 4; i++) {
 481                                         if (((devc->capture_flags >> 2) &
 482                                              (1 << i)) == 0) {
 483                                                 /*
 484                                                  * This channel group was
 485                                                  * enabled, copy from received
 486                                                  * sample.
 487                                                  */
 488                                                 tmp_sample[i] =
 489                                                         devc->sample[j++];
 490                                         }
 491                                 }
 492                                 memcpy(devc->sample, tmp_sample, 4);
 493                                 sr_spew("Expanded sample: 0x%.2hhx%.2hhx%.2hhx%.2hhx ",
 494                                         devc->sample[3], devc->sample[2],
 495                                         devc->sample[1], devc->sample[0]);
 496                         }
 497
 498                         /*
 499                          * the OLS sends its sample buffer backwards.
 500                          * store it in reverse order here, so we can dump
 501                          * this on the session bus later.
 502                          */
 503                         offset = (devc->limit_samples - devc->num_samples) * 4;
 504                         for (i = 0; i <= devc->rle_count; i++) {
 505                                 memcpy(devc->raw_sample_buf + offset + (i * 4),
 506                                        devc->sample, 4);
 507                         }
 508                         memset(devc->sample, 0, 4);
 509                         devc->num_bytes = 0;
 510                         devc->rle_count = 0;
 511                 }
 512         } else {
 513                 /*
 514                  * This is the main loop telling us a timeout was reached, or
 515                  * we've acquired all the samples we asked for -- we're done.
 516                  * Send the (properly-ordered) buffer to the frontend.
 517                  */
 518                 sr_dbg("Received %d bytes, %d samples, %d decompressed samples.",
 519                        devc->cnt_bytes, devc->cnt_samples,
 520                        devc->cnt_samples_rle);
 521                 if (devc->trigger_at_smpl != OLS_NO_TRIGGER) {
 522                         /*
 523                          * A trigger was set up, so we need to tell the frontend
 524                          * about it.
 525                          */
 526                         if (devc->trigger_at_smpl > 0) {
 527                                 /* There are pre-trigger samples, send those first. */
 528                                 packet.type = SR_DF_LOGIC;
 529                                 packet.payload = &logic;
 530                                 logic.length = devc->trigger_at_smpl * 4;
 531                                 logic.unitsize = 4;
 532                                 logic.data = devc->raw_sample_buf +
 533                                              (devc->limit_samples -
 534                                               devc->num_samples) *
 535                                                      4;
 536                                 sr_session_send(sdi, &packet);
 537                         }
 538
 539                         /* Send the trigger. */
 540                         std_session_send_df_trigger(sdi);
 541                 }
 542
 543                 /* Send post-trigger / all captured samples. */
 544                 int num_pre_trigger_samples = devc->trigger_at_smpl ==
 545                                                               OLS_NO_TRIGGER ?
 546                                                             0 :
 547                                                             devc->trigger_at_smpl;
 548                 packet.type = SR_DF_LOGIC;
 549                 packet.payload = &logic;
 550                 logic.length =
 551                         (devc->num_samples - num_pre_trigger_samples) * 4;
 552                 logic.unitsize = 4;
 553                 logic.data = devc->raw_sample_buf +
 554                              (num_pre_trigger_samples + devc->limit_samples -
 555                               devc->num_samples) *
 556                                      4;
 557                 sr_session_send(sdi, &packet);
 558
 559                 g_free(devc->raw_sample_buf);
 560
 561                 serial_flush(serial);
 562                 abort_acquisition(sdi);
 563         }
 564
 565         return TRUE;
 566 }
 567
 568 static int
 569 ols_set_basic_trigger_stage(const struct ols_basic_trigger_desc *trigger_desc,
 570                             struct sr_serial_dev_inst *serial, int stage)
 571 {
 572         uint8_t cmd, arg[4];
 573
 574         cmd = CMD_SET_BASIC_TRIGGER_MASK0 + stage * 4;
 575         if (ols_send_longdata(serial, cmd, trigger_desc->trigger_mask[stage]) != SR_OK)
 576                 return SR_ERR;
 577
 578         cmd = CMD_SET_BASIC_TRIGGER_VALUE0 + stage * 4;
 579         if (ols_send_longdata(serial, cmd, trigger_desc->trigger_value[stage]) != SR_OK)
 580                 return SR_ERR;
 581
 582         cmd = CMD_SET_BASIC_TRIGGER_CONFIG0 + stage * 4;
 583         arg[0] = arg[1] = arg[3] = 0x00;
 584         arg[2] = stage;
 585         if (stage == trigger_desc->num_stages - 1)
 586                 /* Last stage, fire when this one matches. */
 587                 arg[3] |= TRIGGER_START;
 588         if (send_longcommand(serial, cmd, arg) != SR_OK)
 589                 return SR_ERR;
 590
 591         return SR_OK;
 592 }
 593
 594 SR_PRIV int ols_prepare_acquisition(const struct sr_dev_inst *sdi)
 595 {
 596         int ret;
 597
 598         struct dev_context *devc = sdi->priv;
 599         struct sr_serial_dev_inst *serial = sdi->conn;
 600
 601         int num_changroups = 0;
 602         uint8_t changroup_mask = 0;
 603         uint32_t channel_mask = ols_channel_mask(sdi);
 604         for (unsigned int i = 0; i < 4; i++) {
 605                 if (channel_mask & (0xff << (i * 8))) {
 606                         changroup_mask |= (1 << i);
 607                         num_changroups++;
 608                 }
 609         }
 610
 611         /*
 612          * Limit readcount to prevent reading past the end of the hardware
 613          * buffer. Rather read too many samples than too few.
 614          */
 615         uint32_t samplecount =
 616                 MIN(devc->max_samples / num_changroups, devc->limit_samples);
 617         uint32_t readcount = (samplecount + 3) / 4;
 618         uint32_t delaycount;
 619
 620         /* Basic triggers. */
 621         struct ols_basic_trigger_desc basic_trigger_desc;
 622         if (convert_trigger(sdi, &basic_trigger_desc) != SR_OK) {
 623                 sr_err("Failed to configure channels.");
 624                 return SR_ERR;
 625         }
 626         if (basic_trigger_desc.num_stages > 0) {
 627                 /*
 628                  * According to http://mygizmos.org/ols/Logic-Sniffer-FPGA-Spec.pdf
 629                  * reset command must be send prior each arm command
 630                  */
 631                 sr_dbg("Send reset command before trigger configure");
 632                 if (ols_send_reset(serial) != SR_OK)
 633                         return SR_ERR;
 634
 635                 delaycount = readcount * (1 - devc->capture_ratio / 100.0);
 636                 devc->trigger_at_smpl = (readcount - delaycount) * 4 -
 637                                         basic_trigger_desc.num_stages;
 638                 for (int i = 0; i < basic_trigger_desc.num_stages; i++) {
 639                         sr_dbg("Setting OLS stage %d trigger.", i);
 640                         if ((ret = ols_set_basic_trigger_stage(
 641                                      &basic_trigger_desc, serial, i)) != SR_OK)
 642                                 return ret;
 643                 }
 644         } else {
 645                 /* No triggers configured, force trigger on first stage. */
 646                 sr_dbg("Forcing trigger at stage 0.");
 647                 basic_trigger_desc.num_stages = 1;
 648                 if ((ret = ols_set_basic_trigger_stage(&basic_trigger_desc,
 649                                                        serial, 0)) != SR_OK)
 650                         return ret;
 651                 delaycount = readcount;
 652         }
 653
 654         /* Samplerate. */
 655         sr_dbg("Setting samplerate to %" PRIu64 "Hz (divider %u)",
 656                devc->cur_samplerate, devc->cur_samplerate_divider);
 657         if (ols_send_longdata(serial, CMD_SET_DIVIDER,
 658                               devc->cur_samplerate_divider & 0x00FFFFFF) != SR_OK)
 659                 return SR_ERR;
 660
 661         /* Send sample limit and pre/post-trigger capture ratio. */
 662         sr_dbg("Setting sample limit %d, trigger point at %d",
 663                (readcount - 1) * 4, (delaycount - 1) * 4);
 664
 665         if (devc->max_samples > 256 * 1024) {
 666                 if (ols_send_longdata(serial, CMD_CAPTURE_READCOUNT,
 667                                       readcount - 1) != SR_OK)
 668                         return SR_ERR;
 669                 if (ols_send_longdata(serial, CMD_CAPTURE_DELAYCOUNT,
 670                                       delaycount - 1) != SR_OK)
 671                         return SR_ERR;
 672         } else {
 673                 uint8_t arg[4];
 674                 WL16(&arg[0], readcount - 1);
 675                 WL16(&arg[2], delaycount - 1);
 676                 if (send_longcommand(serial, CMD_CAPTURE_SIZE, arg) != SR_OK)
 677                         return SR_ERR;
 678         }
 679
 680         /* Flag register. */
 681         sr_dbg("Setting intpat %s, extpat %s, RLE %s, noise_filter %s, demux %s, "
 682                "%s clock%s",
 683                devc->capture_flags & CAPTURE_FLAG_INTERNAL_TEST_MODE ? "on" :
 684                                                                              "off",
 685                devc->capture_flags & CAPTURE_FLAG_EXTERNAL_TEST_MODE ? "on" :
 686                                                                              "off",
 687                devc->capture_flags & CAPTURE_FLAG_RLE ? "on" : "off",
 688                devc->capture_flags & CAPTURE_FLAG_NOISE_FILTER ? "on" : "off",
 689                devc->capture_flags & CAPTURE_FLAG_DEMUX ? "on" : "off",
 690                devc->capture_flags & CAPTURE_FLAG_CLOCK_EXTERNAL ? "external" :
 691                                                                          "internal",
 692                devc->capture_flags & CAPTURE_FLAG_CLOCK_EXTERNAL ?
 693                              (devc->capture_flags & CAPTURE_FLAG_INVERT_EXT_CLOCK ?
 694                                       " on falling edge" :
 695                                       "on rising edge") :
 696                              "");
 697
 698         /*
 699          * Enable/disable OLS channel groups in the flag register according
 700          * to the channel mask. 1 means "disable channel".
 701          */
 702         devc->capture_flags &= ~0x3c;
 703         devc->capture_flags |= ~(changroup_mask << 2) & 0x3c;
 704
 705         /* RLE mode is always zero, for now. */
 706
 707         if (ols_send_longdata(serial, CMD_SET_FLAGS, devc->capture_flags) != SR_OK)
 708                 return SR_ERR;
 709
 710         return SR_OK;
 711 }