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