src/hardware/pipistrello-ols/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 "protocol.h"
  21
  22 extern SR_PRIV struct sr_dev_driver p_ols_driver_info;
  23 static struct sr_dev_driver *di = &p_ols_driver_info;
  24
  25 SR_PRIV int write_shortcommand(struct dev_context *devc, uint8_t command)
  26 {
  27         uint8_t buf[1];
  28         int bytes_written;
  29
  30         sr_dbg("Sending cmd 0x%.2x.", command);
  31         buf[0] = command;
  32         bytes_written = ftdi_write_data(devc->ftdic, buf, 1);
  33         if (bytes_written < 0) {
  34                 sr_err("Failed to write FTDI data (%d): %s.",
  35                        bytes_written, ftdi_get_error_string(devc->ftdic));
  36                 return SR_ERR;
  37         } else if (bytes_written != 1) {
  38                 sr_err("FTDI write error, only %d/%d bytes written: %s.",
  39                        bytes_written, 1, ftdi_get_error_string(devc->ftdic));
  40                 return SR_ERR;
  41         }
  42
  43         return SR_OK;
  44 }
  45
  46 SR_PRIV int write_longcommand(struct dev_context *devc, uint8_t command, uint8_t *data)
  47 {
  48         uint8_t buf[5];
  49         int bytes_written;
  50
  51         sr_dbg("Sending cmd 0x%.2x data 0x%.2x%.2x%.2x%.2x.", command,
  52                         data[0], data[1], data[2], data[3]);
  53         buf[0] = command;
  54         buf[1] = data[0];
  55         buf[2] = data[1];
  56         buf[3] = data[2];
  57         buf[4] = data[3];
  58         bytes_written = ftdi_write_data(devc->ftdic, buf, 5);
  59         if (bytes_written < 0) {
  60                 sr_err("Failed to write FTDI data (%d): %s.",
  61                        bytes_written, ftdi_get_error_string(devc->ftdic));
  62                 return SR_ERR;
  63         } else if (bytes_written != 5) {
  64                 sr_err("FTDI write error, only %d/%d bytes written: %s.",
  65                        bytes_written, 1, ftdi_get_error_string(devc->ftdic));
  66                 return SR_ERR;
  67         }
  68
  69         return SR_OK;
  70 }
  71
  72 SR_PRIV int p_ols_open(struct dev_context *devc)
  73 {
  74         int ret;
  75
  76         /* Note: Caller checks devc and devc->ftdic. */
  77
  78         /* Select interface B, otherwise communication will fail. */
  79         ret = ftdi_set_interface(devc->ftdic, INTERFACE_B);
  80         if (ret < 0) {
  81                 sr_err("Failed to set FTDI interface B (%d): %s", ret,
  82                        ftdi_get_error_string(devc->ftdic));
  83                 return SR_ERR;
  84         }
  85         sr_dbg("FTDI chip interface B set successfully.");
  86
  87         /* Check for the device and temporarily open it. */
  88         ret = ftdi_usb_open_desc(devc->ftdic, USB_VENDOR_ID, USB_DEVICE_ID,
  89                                  USB_IPRODUCT, NULL);
  90         if (ret < 0) {
  91                 /* Log errors, except for -3 ("device not found"). */
  92                 if (ret != -3)
  93                         sr_err("Failed to open device (%d): %s", ret,
  94                                ftdi_get_error_string(devc->ftdic));
  95                 return SR_ERR;
  96         }
  97         sr_dbg("FTDI device opened successfully.");
  98
  99         /* Purge RX/TX buffers in the FTDI chip. */
 100         if ((ret = ftdi_usb_purge_buffers(devc->ftdic)) < 0) {
 101                 sr_err("Failed to purge FTDI RX/TX buffers (%d): %s.",
 102                        ret, ftdi_get_error_string(devc->ftdic));
 103                 goto err_open_close_ftdic;
 104         }
 105         sr_dbg("FTDI chip buffers purged successfully.");
 106
 107         /* Reset the FTDI bitmode. */
 108         ret = ftdi_set_bitmode(devc->ftdic, 0xff, BITMODE_RESET);
 109         if (ret < 0) {
 110                 sr_err("Failed to reset the FTDI chip bitmode (%d): %s.",
 111                        ret, ftdi_get_error_string(devc->ftdic));
 112                 goto err_open_close_ftdic;
 113         }
 114         sr_dbg("FTDI chip bitmode reset successfully.");
 115
 116         /* Set the FTDI latency timer to 16. */
 117         ret = ftdi_set_latency_timer(devc->ftdic, 16);
 118         if (ret < 0) {
 119                 sr_err("Failed to set FTDI latency timer (%d): %s.",
 120                        ret, ftdi_get_error_string(devc->ftdic));
 121                 goto err_open_close_ftdic;
 122         }
 123         sr_dbg("FTDI chip latency timer set successfully.");
 124
 125         /* Set the FTDI read data chunk size to 64kB. */
 126         ret = ftdi_read_data_set_chunksize(devc->ftdic, 64 * 1024);
 127         if (ret < 0) {
 128                 sr_err("Failed to set FTDI read data chunk size (%d): %s.",
 129                        ret, ftdi_get_error_string(devc->ftdic));
 130                 goto err_open_close_ftdic;
 131         }
 132         sr_dbg("FTDI chip read data chunk size set successfully.");
 133
 134         return SR_OK;
 135
 136 err_open_close_ftdic:
 137         ftdi_usb_close(devc->ftdic);
 138         return SR_ERR;
 139 }
 140
 141 SR_PRIV int p_ols_close(struct dev_context *devc)
 142 {
 143         int ret;
 144
 145         /* Note: Caller checks devc and devc->ftdic. */
 146
 147         if ((ret = ftdi_usb_close(devc->ftdic)) < 0) {
 148                 sr_err("Failed to close FTDI device (%d): %s.",
 149                        ret, ftdi_get_error_string(devc->ftdic));
 150                 return SR_ERR;
 151         }
 152
 153         return SR_OK;
 154 }
 155
 156 /* Configures the channel mask based on which channels are enabled. */
 157 SR_PRIV void pols_channel_mask(const struct sr_dev_inst *sdi)
 158 {
 159         struct dev_context *devc;
 160         struct sr_channel *channel;
 161         const GSList *l;
 162
 163         devc = sdi->priv;
 164
 165         devc->channel_mask = 0;
 166         for (l = sdi->channels; l; l = l->next) {
 167                 channel = l->data;
 168                 if (channel->enabled)
 169                         devc->channel_mask |= 1 << channel->index;
 170         }
 171 }
 172
 173 SR_PRIV int pols_convert_trigger(const struct sr_dev_inst *sdi)
 174 {
 175         struct dev_context *devc;
 176         struct sr_trigger *trigger;
 177         struct sr_trigger_stage *stage;
 178         struct sr_trigger_match *match;
 179         const GSList *l, *m;
 180         int i;
 181
 182         devc = sdi->priv;
 183
 184         devc->num_stages = 0;
 185         for (i = 0; i < NUM_TRIGGER_STAGES; i++) {
 186                 devc->trigger_mask[i] = 0;
 187                 devc->trigger_value[i] = 0;
 188                 devc->trigger_edge[i] = 0;
 189         }
 190
 191         if (!(trigger = sr_session_trigger_get(sdi->session)))
 192                 return SR_OK;
 193
 194         devc->num_stages = g_slist_length(trigger->stages);
 195         if (devc->num_stages > NUM_TRIGGER_STAGES) {
 196                 sr_err("This device only supports %d trigger stages.",
 197                                 NUM_TRIGGER_STAGES);
 198                 return SR_ERR;
 199         }
 200
 201         for (l = trigger->stages; l; l = l->next) {
 202                 stage = l->data;
 203                 for (m = stage->matches; m; m = m->next) {
 204                         match = m->data;
 205                         if (!match->channel->enabled)
 206                                 /* Ignore disabled channels with a trigger. */
 207                                 continue;
 208                         devc->trigger_mask[stage->stage] |= 1 << match->channel->index;
 209                         if (match->match == SR_TRIGGER_ONE || match->match == SR_TRIGGER_RISING)
 210                                 devc->trigger_value[stage->stage] |= 1 << match->channel->index;
 211                         if (match->match == SR_TRIGGER_RISING || match->match == SR_TRIGGER_FALLING)
 212                                 devc->trigger_edge[stage->stage] |= 1 << match->channel->index;
 213                 }
 214         }
 215
 216         return SR_OK;
 217 }
 218
 219 SR_PRIV struct sr_dev_inst *p_ols_get_metadata(uint8_t *buf, int bytes_read, struct dev_context *devc)
 220 {
 221         struct sr_dev_inst *sdi;
 222         struct sr_channel *ch;
 223         uint32_t tmp_int, ui;
 224         uint8_t key, type, token;
 225         GString *tmp_str, *devname, *version;
 226         guchar tmp_c;
 227         int index, i;
 228
 229         sdi = g_malloc0(sizeof(struct sr_dev_inst));
 230         sdi->status = SR_ST_INACTIVE;
 231         sdi->driver = di;
 232         sdi->priv = devc;
 233
 234         devname = g_string_new("");
 235         version = g_string_new("");
 236
 237         index = 0;
 238         while (index < bytes_read) {
 239                 key = buf[index++];
 240                 if (key == 0x00) {
 241                         sr_dbg("Got metadata key 0x00, metadata ends.");
 242                         break;
 243                 }
 244                 type = key >> 5;
 245                 token = key & 0x1f;
 246                 switch (type) {
 247                 case 0:
 248                         /* NULL-terminated string */
 249                         tmp_str = g_string_new("");
 250                         while ((index < bytes_read) && ((tmp_c = buf[index++]) != '\0'))
 251                                 g_string_append_c(tmp_str, tmp_c);
 252                         sr_dbg("Got metadata key 0x%.2x value '%s'.",
 253                                key, tmp_str->str);
 254                         switch (token) {
 255                         case 0x01:
 256                                 /* Device name */
 257                                 devname = g_string_append(devname, tmp_str->str);
 258                                 break;
 259                         case 0x02:
 260                                 /* FPGA firmware version */
 261                                 if (version->len)
 262                                         g_string_append(version, ", ");
 263                                 g_string_append(version, "FPGA version ");
 264                                 g_string_append(version, tmp_str->str);
 265                                 break;
 266                         case 0x03:
 267                                 /* Ancillary version */
 268                                 if (version->len)
 269                                         g_string_append(version, ", ");
 270                                 g_string_append(version, "Ancillary version ");
 271                                 g_string_append(version, tmp_str->str);
 272                                 break;
 273                         default:
 274                                 sr_info("Unknown token 0x%.2x: '%s'",
 275                                         token, tmp_str->str);
 276                                 break;
 277                         }
 278                         g_string_free(tmp_str, TRUE);
 279                         break;
 280                 case 1:
 281                         /* 32-bit unsigned integer */
 282                         tmp_int = 0;
 283                         for (i = 0; i < 4; i++) {
 284                                 tmp_int = (tmp_int << 8) | buf[index++];
 285                         }
 286                         sr_dbg("Got metadata key 0x%.2x value 0x%.8x.",
 287                                key, tmp_int);
 288                         switch (token) {
 289                         case 0x00:
 290                                 /* Number of usable channels */
 291                                 for (ui = 0; ui < tmp_int; ui++) {
 292                                         ch = sr_channel_new(ui, SR_CHANNEL_LOGIC, TRUE,
 293                                                         p_ols_channel_names[ui]);
 294                                         sdi->channels = g_slist_append(sdi->channels, ch);
 295                                 }
 296                                 break;
 297                         case 0x01:
 298                                 /* Amount of sample memory available (bytes) */
 299                                 devc->max_samplebytes = tmp_int;
 300                                 break;
 301                         case 0x02:
 302                                 /* Amount of dynamic memory available (bytes) */
 303                                 /* what is this for? */
 304                                 break;
 305                         case 0x03:
 306                                 /* Maximum sample rate (hz) */
 307                                 devc->max_samplerate = tmp_int;
 308                                 break;
 309                         case 0x04:
 310                                 /* protocol version */
 311                                 devc->protocol_version = tmp_int;
 312                                 break;
 313                         default:
 314                                 sr_info("Unknown token 0x%.2x: 0x%.8x.",
 315                                         token, tmp_int);
 316                                 break;
 317                         }
 318                         break;
 319                 case 2:
 320                         /* 8-bit unsigned integer */
 321                         tmp_c = buf[index++];
 322                         sr_dbg("Got metadata key 0x%.2x value 0x%.2x.",
 323                                key, tmp_c);
 324                         switch (token) {
 325                         case 0x00:
 326                                 /* Number of usable channels */
 327                                 for (ui = 0; ui < tmp_c; ui++) {
 328                                         ch = sr_channel_new(ui, SR_CHANNEL_LOGIC, TRUE,
 329                                                         p_ols_channel_names[ui]);
 330                                         sdi->channels = g_slist_append(sdi->channels, ch);
 331                                 }
 332                                 break;
 333                         case 0x01:
 334                                 /* protocol version */
 335                                 devc->protocol_version = tmp_c;
 336                                 break;
 337                         default:
 338                                 sr_info("Unknown token 0x%.2x: 0x%.2x.",
 339                                         token, tmp_c);
 340                                 break;
 341                         }
 342                         break;
 343                 default:
 344                         /* unknown type */
 345                         break;
 346                 }
 347         }
 348
 349         sdi->model = devname->str;
 350         sdi->version = version->str;
 351         g_string_free(devname, FALSE);
 352         g_string_free(version, FALSE);
 353
 354         return sdi;
 355 }
 356
 357 SR_PRIV int p_ols_set_samplerate(const struct sr_dev_inst *sdi,
 358                 const uint64_t samplerate)
 359 {
 360         struct dev_context *devc;
 361
 362         devc = sdi->priv;
 363         if (devc->max_samplerate && samplerate > devc->max_samplerate)
 364                 return SR_ERR_SAMPLERATE;
 365
 366         if (samplerate > CLOCK_RATE) {
 367                 sr_info("Enabling demux mode.");
 368                 devc->flag_reg |= FLAG_DEMUX;
 369                 devc->flag_reg &= ~FLAG_FILTER;
 370                 devc->max_channels = NUM_CHANNELS / 2;
 371                 devc->cur_samplerate_divider = (CLOCK_RATE * 2 / samplerate) - 1;
 372         } else {
 373                 sr_info("Disabling demux mode.");
 374                 devc->flag_reg &= ~FLAG_DEMUX;
 375                 devc->flag_reg |= FLAG_FILTER;
 376                 devc->max_channels = NUM_CHANNELS;
 377                 devc->cur_samplerate_divider = (CLOCK_RATE / samplerate) - 1;
 378         }
 379
 380         /* Calculate actual samplerate used and complain if it is different
 381          * from the requested.
 382          */
 383         devc->cur_samplerate = CLOCK_RATE / (devc->cur_samplerate_divider + 1);
 384         if (devc->flag_reg & FLAG_DEMUX)
 385                 devc->cur_samplerate *= 2;
 386         if (devc->cur_samplerate != samplerate)
 387                 sr_info("Can't match samplerate %" PRIu64 ", using %"
 388                        PRIu64 ".", samplerate, devc->cur_samplerate);
 389
 390         return SR_OK;
 391 }
 392
 393
 394 SR_PRIV int p_ols_receive_data(int fd, int revents, void *cb_data)
 395 {
 396         struct dev_context *devc;
 397         struct sr_dev_inst *sdi;
 398         struct sr_datafeed_packet packet;
 399         struct sr_datafeed_logic logic;
 400         uint32_t sample;
 401         int num_channels, offset, j;
 402         int bytes_read, index;
 403         unsigned int i;
 404         unsigned char byte;
 405
 406         (void)fd;
 407         (void)revents;
 408
 409         sdi = cb_data;
 410         devc = sdi->priv;
 411
 412         if (devc->num_transfers++ == 0) {
 413                 devc->raw_sample_buf = g_try_malloc(devc->limit_samples * 4);
 414                 if (!devc->raw_sample_buf) {
 415                         sr_err("Sample buffer malloc failed.");
 416                         return FALSE;
 417                 }
 418                 /* fill with 1010... for debugging */
 419                 memset(devc->raw_sample_buf, 0x82, devc->limit_samples * 4);
 420         }
 421
 422         if ((devc->num_samples < devc->limit_samples) && (devc->cnt_samples < devc->max_samples)) {
 423
 424                 num_channels = 0;
 425                 for (i = NUM_CHANNELS; i > 0x02; i /= 2) {
 426                         if ((devc->flag_reg & i) == 0) {
 427                                 num_channels++;
 428                         }
 429                 }
 430
 431                 /* Get a block of data. */
 432                 bytes_read = ftdi_read_data(devc->ftdic, devc->ftdi_buf, FTDI_BUF_SIZE);
 433                 if (bytes_read < 0) {
 434                         sr_err("Failed to read FTDI data (%d): %s.",
 435                                bytes_read, ftdi_get_error_string(devc->ftdic));
 436                         sdi->driver->dev_acquisition_stop(sdi, sdi);
 437                         return FALSE;
 438                 }
 439                 if (bytes_read == 0) {
 440                         sr_spew("Received 0 bytes, nothing to do.");
 441                         return TRUE;
 442                 }
 443
 444                 sr_dbg("Received %d bytes", bytes_read);
 445
 446                 index = 0;
 447                 while (index < bytes_read) {
 448                         byte = devc->ftdi_buf[index++];
 449                         devc->cnt_bytes++;
 450
 451                         devc->sample[devc->num_bytes++] = byte;
 452                         sr_spew("Received byte 0x%.2x.", byte);
 453
 454                         if ((devc->flag_reg & FLAG_DEMUX) && (devc->flag_reg & FLAG_RLE)) {
 455                                 /* RLE in demux mode must be processed differently
 456                                 * since in this case the RLE encoder is operating on pairs of samples.
 457                                 */
 458                                 if (devc->num_bytes == num_channels * 2) {
 459                                         devc->cnt_samples += 2;
 460                                         devc->cnt_samples_rle += 2;
 461                                         /*
 462                                          * Got a sample pair. Convert from the OLS's little-endian
 463                                          * sample to the local format.
 464                                          */
 465                                         sample = devc->sample[0] | (devc->sample[1] << 8) \
 466                                                         | (devc->sample[2] << 16) | (devc->sample[3] << 24);
 467                                         sr_spew("Received sample pair 0x%.*x.", devc->num_bytes * 2, sample);
 468
 469                                         /*
 470                                          * In RLE mode the high bit of the sample pair is the
 471                                          * "count" flag, meaning this sample pair is the number
 472                                          * of times the previous sample pair occurred.
 473                                          */
 474                                         if (devc->sample[devc->num_bytes - 1] & 0x80) {
 475                                                 /* Clear the high bit. */
 476                                                 sample &= ~(0x80 << (devc->num_bytes - 1) * 8);
 477                                                 devc->rle_count = sample;
 478                                                 devc->cnt_samples_rle += devc->rle_count * 2;
 479                                                 sr_dbg("RLE count: %u.", devc->rle_count * 2);
 480                                                 devc->num_bytes = 0;
 481                                                 continue;
 482                                         }
 483                                         devc->num_samples += (devc->rle_count + 1) * 2;
 484                                         if (devc->num_samples > devc->limit_samples) {
 485                                                 /* Save us from overrunning the buffer. */
 486                                                 devc->rle_count -= (devc->num_samples - devc->limit_samples) / 2;
 487                                                 devc->num_samples = devc->limit_samples;
 488                                                 index = bytes_read;
 489                                         }
 490
 491                                         /*
 492                                          * Some channel groups may have been turned
 493                                          * off, to speed up transfer between the
 494                                          * hardware and the PC. Expand that here before
 495                                          * submitting it over the session bus --
 496                                          * whatever is listening on the bus will be
 497                                          * expecting a full 32-bit sample, based on
 498                                          * the number of channels.
 499                                          */
 500                                         j = 0;
 501                                         /* expand first sample */
 502                                         memset(devc->tmp_sample, 0, 4);
 503                                         for (i = 0; i < 2; i++) {
 504                                                 if (((devc->flag_reg >> 2) & (1 << i)) == 0) {
 505                                                         /*
 506                                                          * This channel group was
 507                                                          * enabled, copy from received
 508                                                          * sample.
 509                                                          */
 510                                                         devc->tmp_sample[i] = devc->sample[j++];
 511                                                 }
 512                                         }
 513                                         /* Clear out the most significant bit of the sample */
 514                                         devc->tmp_sample[devc->num_bytes - 1] &= 0x7f;
 515                                         sr_spew("Expanded sample 1: 0x%.8x.", devc->tmp_sample);
 516
 517                                         /* expand second sample */
 518                                         memset(devc->tmp_sample2, 0, 4);
 519                                         for (i = 0; i < 2; i++) {
 520                                                 if (((devc->flag_reg >> 2) & (1 << i)) == 0) {
 521                                                         /*
 522                                                          * This channel group was
 523                                                          * enabled, copy from received
 524                                                          * sample.
 525                                                          */
 526                                                         devc->tmp_sample2[i] = devc->sample[j++];
 527                                                 }
 528                                         }
 529                                         /* Clear out the most significant bit of the sample */
 530                                         devc->tmp_sample2[devc->num_bytes - 1] &= 0x7f;
 531                                         sr_spew("Expanded sample 2: 0x%.8x.", devc->tmp_sample2);
 532
 533                                         /*
 534                                          * OLS sends its sample buffer backwards.
 535                                          * store it in reverse order here, so we can dump
 536                                          * this on the session bus later.
 537                                          */
 538                                         offset = (devc->limit_samples - devc->num_samples) * 4;
 539                                         for (i = 0; i <= devc->rle_count; i++) {
 540                                                 memcpy(devc->raw_sample_buf + offset + (i * 8),
 541                                                                          devc->tmp_sample2, 4);
 542                                                 memcpy(devc->raw_sample_buf + offset + (4 + (i * 8)),
 543                                                                          devc->tmp_sample, 4);
 544                                         }
 545                                         memset(devc->sample, 0, 4);
 546                                         devc->num_bytes = 0;
 547                                         devc->rle_count = 0;
 548                                 }
 549                         }
 550                         else {
 551                                 if (devc->num_bytes == num_channels) {
 552                                         devc->cnt_samples++;
 553                                         devc->cnt_samples_rle++;
 554                                         /*
 555                                          * Got a full sample. Convert from the OLS's little-endian
 556                                          * sample to the local format.
 557                                          */
 558                                         sample = devc->sample[0] | (devc->sample[1] << 8) \
 559                                                         | (devc->sample[2] << 16) | (devc->sample[3] << 24);
 560                                         sr_spew("Received sample 0x%.*x.", devc->num_bytes * 2, sample);
 561                                         if (devc->flag_reg & FLAG_RLE) {
 562                                                 /*
 563                                                  * In RLE mode the high bit of the sample is the
 564                                                  * "count" flag, meaning this sample is the number
 565                                                  * of times the previous sample occurred.
 566                                                  */
 567                                                 if (devc->sample[devc->num_bytes - 1] & 0x80) {
 568                                                         /* Clear the high bit. */
 569                                                         sample &= ~(0x80 << (devc->num_bytes - 1) * 8);
 570                                                         devc->rle_count = sample;
 571                                                         devc->cnt_samples_rle += devc->rle_count;
 572                                                         sr_dbg("RLE count: %u.", devc->rle_count);
 573                                                         devc->num_bytes = 0;
 574                                                         continue;
 575                                                 }
 576                                         }
 577                                         devc->num_samples += devc->rle_count + 1;
 578                                         if (devc->num_samples > devc->limit_samples) {
 579                                                 /* Save us from overrunning the buffer. */
 580                                                 devc->rle_count -= devc->num_samples - devc->limit_samples;
 581                                                 devc->num_samples = devc->limit_samples;
 582                                                 index = bytes_read;
 583                                         }
 584
 585                                         if (num_channels < 4) {
 586                                                 /*
 587                                                  * Some channel groups may have been turned
 588                                                  * off, to speed up transfer between the
 589                                                  * hardware and the PC. Expand that here before
 590                                                  * submitting it over the session bus --
 591                                                  * whatever is listening on the bus will be
 592                                                  * expecting a full 32-bit sample, based on
 593                                                  * the number of channels.
 594                                                  */
 595                                                 j = 0;
 596                                                 memset(devc->tmp_sample, 0, 4);
 597                                                 for (i = 0; i < 4; i++) {
 598                                                         if (((devc->flag_reg >> 2) & (1 << i)) == 0) {
 599                                                                 /*
 600                                                                  * This channel group was
 601                                                                  * enabled, copy from received
 602                                                                  * sample.
 603                                                                  */
 604                                                                 devc->tmp_sample[i] = devc->sample[j++];
 605                                                         }
 606                                                 }
 607                                                 memcpy(devc->sample, devc->tmp_sample, 4);
 608                                                 sr_spew("Expanded sample: 0x%.8x.", sample);
 609                                         }
 610
 611                                         /*
 612                                          * Pipistrello OLS sends its sample buffer backwards.
 613                                          * store it in reverse order here, so we can dump
 614                                          * this on the session bus later.
 615                                          */
 616                                         offset = (devc->limit_samples - devc->num_samples) * 4;
 617                                         for (i = 0; i <= devc->rle_count; i++) {
 618                                                 memcpy(devc->raw_sample_buf + offset + (i * 4),
 619                                                                          devc->sample, 4);
 620                                         }
 621                                         memset(devc->sample, 0, 4);
 622                                         devc->num_bytes = 0;
 623                                         devc->rle_count = 0;
 624                                 }
 625                         }
 626                 }
 627                 return TRUE;
 628         } else {
 629                 do bytes_read = ftdi_read_data(devc->ftdic, devc->ftdi_buf, FTDI_BUF_SIZE);
 630                 while (bytes_read > 0);
 631
 632                 /*
 633                  * We've acquired all the samples we asked for -- we're done.
 634                  * Send the (properly-ordered) buffer to the frontend.
 635                  */
 636                 sr_dbg("Received %d bytes, %d samples, %d decompressed samples.",
 637                                 devc->cnt_bytes, devc->cnt_samples,
 638                                 devc->cnt_samples_rle);
 639                 if (devc->trigger_at != -1) {
 640                         /*
 641                          * A trigger was set up, so we need to tell the frontend
 642                          * about it.
 643                          */
 644                         if (devc->trigger_at > 0) {
 645                                 /* There are pre-trigger samples, send those first. */
 646                                 packet.type = SR_DF_LOGIC;
 647                                 packet.payload = &logic;
 648                                 logic.length = devc->trigger_at * 4;
 649                                 logic.unitsize = 4;
 650                                 logic.data = devc->raw_sample_buf +
 651                                         (devc->limit_samples - devc->num_samples) * 4;
 652                                 sr_session_send(cb_data, &packet);
 653                         }
 654
 655                         /* Send the trigger. */
 656                         packet.type = SR_DF_TRIGGER;
 657                         sr_session_send(cb_data, &packet);
 658
 659                         /* Send post-trigger samples. */
 660                         packet.type = SR_DF_LOGIC;
 661                         packet.payload = &logic;
 662                         logic.length = (devc->num_samples * 4) - (devc->trigger_at * 4);
 663                         logic.unitsize = 4;
 664                         logic.data = devc->raw_sample_buf + devc->trigger_at * 4 +
 665                                 (devc->limit_samples - devc->num_samples) * 4;
 666                         sr_session_send(cb_data, &packet);
 667                 } else {
 668                         /* no trigger was used */
 669                         packet.type = SR_DF_LOGIC;
 670                         packet.payload = &logic;
 671                         logic.length = devc->num_samples * 4;
 672                         logic.unitsize = 4;
 673                         logic.data = devc->raw_sample_buf +
 674                                 (devc->limit_samples - devc->num_samples) * 4;
 675                         sr_session_send(cb_data, &packet);
 676                 }
 677                 g_free(devc->raw_sample_buf);
 678
 679                 sdi->driver->dev_acquisition_stop(sdi, cb_data);
 680         }
 681
 682         return TRUE;
 683 }