src/hardware/hantek-6xxx/api.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2015 Christer Ekholm <christerekholm@gmail.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 <math.h>
  22 #include "protocol.h"
  23
  24 /* Max time in ms before we want to check on USB events */
  25 #define TICK 200
  26
  27 #define RANGE(ch) (((float)vdivs[devc->voltage[ch]][0] / vdivs[devc->voltage[ch]][1]) * VDIV_MULTIPLIER)
  28
  29 static const uint32_t scanopts[] = {
  30         SR_CONF_CONN,
  31 };
  32
  33 static const uint32_t drvopts[] = {
  34         SR_CONF_OSCILLOSCOPE,
  35 };
  36
  37 static const uint32_t devopts[] = {
  38         SR_CONF_CONN | SR_CONF_GET,
  39         SR_CONF_LIMIT_SAMPLES | SR_CONF_GET | SR_CONF_SET,
  40         SR_CONF_LIMIT_MSEC | SR_CONF_GET | SR_CONF_SET,
  41         SR_CONF_SAMPLERATE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
  42         SR_CONF_NUM_VDIV | SR_CONF_GET,
  43 };
  44
  45 static const uint32_t devopts_cg[] = {
  46         SR_CONF_VDIV | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
  47         SR_CONF_COUPLING | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
  48 };
  49
  50 static const char *channel_names[] = {
  51         "CH1", "CH2",
  52 };
  53
  54 static const char *dc_coupling[] = {
  55         "DC",
  56 };
  57
  58 static const char *acdc_coupling[] = {
  59         "AC", "DC",
  60 };
  61
  62 static const struct hantek_6xxx_profile dev_profiles[] = {
  63         {
  64                 0x04b4, 0x6022, 0x1d50, 0x608e, 0x0001,
  65                 "Hantek", "6022BE", "fx2lafw-hantek-6022be.fw",
  66                 ARRAY_AND_SIZE(dc_coupling), FALSE,
  67         },
  68         {
  69                 0x8102, 0x8102, 0x1d50, 0x608e, 0x0002,
  70                 "Sainsmart", "DDS120", "fx2lafw-sainsmart-dds120.fw",
  71                 ARRAY_AND_SIZE(acdc_coupling), TRUE,
  72         },
  73         {
  74                 0x04b4, 0x602a, 0x1d50, 0x608e, 0x0003,
  75                 "Hantek", "6022BL", "fx2lafw-hantek-6022bl.fw",
  76                 ARRAY_AND_SIZE(dc_coupling), FALSE,
  77         },
  78         ALL_ZERO
  79 };
  80
  81 static const uint64_t samplerates[] = {
  82         SAMPLERATE_VALUES
  83 };
  84
  85 static const uint64_t vdivs[][2] = {
  86         VDIV_VALUES
  87 };
  88
  89 static int read_channel(const struct sr_dev_inst *sdi, uint32_t amount);
  90
  91 static struct sr_dev_inst *hantek_6xxx_dev_new(const struct hantek_6xxx_profile *prof)
  92 {
  93         struct sr_dev_inst *sdi;
  94         struct sr_channel *ch;
  95         struct sr_channel_group *cg;
  96         struct dev_context *devc;
  97         unsigned int i;
  98
  99         sdi = g_malloc0(sizeof(struct sr_dev_inst));
 100         sdi->status = SR_ST_INITIALIZING;
 101         sdi->vendor = g_strdup(prof->vendor);
 102         sdi->model = g_strdup(prof->model);
 103
 104         for (i = 0; i < ARRAY_SIZE(channel_names); i++) {
 105                 ch = sr_channel_new(sdi, i, SR_CHANNEL_ANALOG, TRUE, channel_names[i]);
 106                 cg = g_malloc0(sizeof(struct sr_channel_group));
 107                 cg->name = g_strdup(channel_names[i]);
 108                 cg->channels = g_slist_append(cg->channels, ch);
 109                 sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
 110         }
 111
 112         devc = g_malloc0(sizeof(struct dev_context));
 113
 114         for (i = 0; i < NUM_CHANNELS; i++) {
 115                 devc->ch_enabled[i] = TRUE;
 116                 devc->voltage[i] = DEFAULT_VOLTAGE;
 117                 devc->coupling[i] = DEFAULT_COUPLING;
 118         }
 119         devc->coupling_vals = prof->coupling_vals;
 120         devc->coupling_tab_size = prof->coupling_tab_size;
 121         devc->has_coupling = prof->has_coupling;
 122
 123         devc->sample_buf = NULL;
 124         devc->sample_buf_write = 0;
 125         devc->sample_buf_size = 0;
 126
 127         devc->profile = prof;
 128         devc->dev_state = IDLE;
 129         devc->samplerate = DEFAULT_SAMPLERATE;
 130
 131         sdi->priv = devc;
 132
 133         return sdi;
 134 }
 135
 136 static int configure_channels(const struct sr_dev_inst *sdi)
 137 {
 138         struct dev_context *devc;
 139         const GSList *l;
 140         int p;
 141         struct sr_channel *ch;
 142         devc = sdi->priv;
 143
 144         g_slist_free(devc->enabled_channels);
 145         devc->enabled_channels = NULL;
 146         memset(devc->ch_enabled, 0, sizeof(devc->ch_enabled));
 147
 148         for (l = sdi->channels, p = 0; l; l = l->next, p++) {
 149                 ch = l->data;
 150                 if (p < NUM_CHANNELS) {
 151                         devc->ch_enabled[p] = ch->enabled;
 152                         devc->enabled_channels = g_slist_append(devc->enabled_channels, ch);
 153                 }
 154         }
 155
 156         return SR_OK;
 157 }
 158
 159 static void clear_helper(struct dev_context *devc)
 160 {
 161         g_slist_free(devc->enabled_channels);
 162 }
 163
 164 static int dev_clear(const struct sr_dev_driver *di)
 165 {
 166         return std_dev_clear_with_callback(di, (std_dev_clear_callback)clear_helper);
 167 }
 168
 169 static GSList *scan(struct sr_dev_driver *di, GSList *options)
 170 {
 171         struct drv_context *drvc;
 172         struct dev_context *devc;
 173         struct sr_dev_inst *sdi;
 174         struct sr_usb_dev_inst *usb;
 175         struct sr_config *src;
 176         const struct hantek_6xxx_profile *prof;
 177         GSList *l, *devices, *conn_devices;
 178         struct libusb_device_descriptor des;
 179         libusb_device **devlist;
 180         int i, j;
 181         const char *conn;
 182         char connection_id[64];
 183
 184         drvc = di->context;
 185
 186         devices = 0;
 187
 188         conn = NULL;
 189         for (l = options; l; l = l->next) {
 190                 src = l->data;
 191                 if (src->key == SR_CONF_CONN) {
 192                         conn = g_variant_get_string(src->data, NULL);
 193                         break;
 194                 }
 195         }
 196         if (conn)
 197                 conn_devices = sr_usb_find(drvc->sr_ctx->libusb_ctx, conn);
 198         else
 199                 conn_devices = NULL;
 200
 201         /* Find all Hantek 60xx devices and upload firmware to all of them. */
 202         libusb_get_device_list(drvc->sr_ctx->libusb_ctx, &devlist);
 203         for (i = 0; devlist[i]; i++) {
 204                 if (conn) {
 205                         usb = NULL;
 206                         for (l = conn_devices; l; l = l->next) {
 207                                 usb = l->data;
 208                                 if (usb->bus == libusb_get_bus_number(devlist[i])
 209                                         && usb->address == libusb_get_device_address(devlist[i]))
 210                                         break;
 211                         }
 212                         if (!l)
 213                                 /* This device matched none of the ones that
 214                                  * matched the conn specification. */
 215                                 continue;
 216                 }
 217
 218                 libusb_get_device_descriptor(devlist[i], &des);
 219
 220                 if (usb_get_port_path(devlist[i], connection_id, sizeof(connection_id)) < 0)
 221                         continue;
 222
 223                 prof = NULL;
 224                 for (j = 0; dev_profiles[j].orig_vid; j++) {
 225                         if (des.idVendor == dev_profiles[j].orig_vid
 226                                 && des.idProduct == dev_profiles[j].orig_pid) {
 227                                 /* Device matches the pre-firmware profile. */
 228                                 prof = &dev_profiles[j];
 229                                 sr_dbg("Found a %s %s.", prof->vendor, prof->model);
 230                                 sdi = hantek_6xxx_dev_new(prof);
 231                                 sdi->connection_id = g_strdup(connection_id);
 232                                 devices = g_slist_append(devices, sdi);
 233                                 devc = sdi->priv;
 234                                 if (ezusb_upload_firmware(drvc->sr_ctx, devlist[i],
 235                                                 USB_CONFIGURATION, prof->firmware) == SR_OK)
 236                                         /* Remember when the firmware on this device was updated. */
 237                                         devc->fw_updated = g_get_monotonic_time();
 238                                 else
 239                                         sr_err("Firmware upload failed.");
 240                                 /* Dummy USB address of 0xff will get overwritten later. */
 241                                 sdi->conn = sr_usb_dev_inst_new(
 242                                                 libusb_get_bus_number(devlist[i]), 0xff, NULL);
 243                                 break;
 244                         } else if (des.idVendor == dev_profiles[j].fw_vid
 245                                 && des.idProduct == dev_profiles[j].fw_pid
 246                                 && des.bcdDevice == dev_profiles[j].fw_prod_ver) {
 247                                 /* Device matches the post-firmware profile. */
 248                                 prof = &dev_profiles[j];
 249                                 sr_dbg("Found a %s %s.", prof->vendor, prof->model);
 250                                 sdi = hantek_6xxx_dev_new(prof);
 251                                 sdi->connection_id = g_strdup(connection_id);
 252                                 sdi->status = SR_ST_INACTIVE;
 253                                 devices = g_slist_append(devices, sdi);
 254                                 sdi->inst_type = SR_INST_USB;
 255                                 sdi->conn = sr_usb_dev_inst_new(
 256                                                 libusb_get_bus_number(devlist[i]),
 257                                                 libusb_get_device_address(devlist[i]), NULL);
 258                                 break;
 259                         }
 260                 }
 261                 if (!prof)
 262                         /* Not a supported VID/PID. */
 263                         continue;
 264         }
 265         libusb_free_device_list(devlist, 1);
 266
 267         return std_scan_complete(di, devices);
 268 }
 269
 270 static int dev_open(struct sr_dev_inst *sdi)
 271 {
 272         struct dev_context *devc;
 273         struct sr_usb_dev_inst *usb;
 274         int64_t timediff_us, timediff_ms;
 275         int err;
 276
 277         devc = sdi->priv;
 278         usb = sdi->conn;
 279
 280         /*
 281          * If the firmware was recently uploaded, wait up to MAX_RENUM_DELAY_MS
 282          * for the FX2 to renumerate.
 283          */
 284         err = SR_ERR;
 285         if (devc->fw_updated > 0) {
 286                 sr_info("Waiting for device to reset.");
 287                 /* Takes >= 300ms for the FX2 to be gone from the USB bus. */
 288                 g_usleep(300 * 1000);
 289                 timediff_ms = 0;
 290                 while (timediff_ms < MAX_RENUM_DELAY_MS) {
 291                         if ((err = hantek_6xxx_open(sdi)) == SR_OK)
 292                                 break;
 293                         g_usleep(100 * 1000);
 294                         timediff_us = g_get_monotonic_time() - devc->fw_updated;
 295                         timediff_ms = timediff_us / 1000;
 296                         sr_spew("Waited %" PRIi64 " ms.", timediff_ms);
 297                 }
 298                 if (timediff_ms < MAX_RENUM_DELAY_MS)
 299                         sr_info("Device came back after %"PRIu64" ms.", timediff_ms);
 300         } else {
 301                 err = hantek_6xxx_open(sdi);
 302         }
 303
 304         if (err != SR_OK) {
 305                 sr_err("Unable to open device.");
 306                 return SR_ERR;
 307         }
 308
 309         err = libusb_claim_interface(usb->devhdl, USB_INTERFACE);
 310         if (err != 0) {
 311                 sr_err("Unable to claim interface: %s.",
 312                         libusb_error_name(err));
 313                 return SR_ERR;
 314         }
 315
 316         return SR_OK;
 317 }
 318
 319 static int dev_close(struct sr_dev_inst *sdi)
 320 {
 321         hantek_6xxx_close(sdi);
 322
 323         return SR_OK;
 324 }
 325
 326 static int config_get(uint32_t key, GVariant **data,
 327         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 328 {
 329         struct dev_context *devc;
 330         struct sr_usb_dev_inst *usb;
 331         const uint64_t *vdiv;
 332         int ch_idx;
 333
 334         switch (key) {
 335         case SR_CONF_NUM_VDIV:
 336                 *data = g_variant_new_int32(ARRAY_SIZE(vdivs));
 337                 break;
 338         }
 339
 340         if (!sdi)
 341                 return SR_ERR_ARG;
 342
 343         devc = sdi->priv;
 344         if (!cg) {
 345                 switch (key) {
 346                 case SR_CONF_SAMPLERATE:
 347                         *data = g_variant_new_uint64(devc->samplerate);
 348                         break;
 349                 case SR_CONF_LIMIT_MSEC:
 350                         *data = g_variant_new_uint64(devc->limit_msec);
 351                         break;
 352                 case SR_CONF_LIMIT_SAMPLES:
 353                         *data = g_variant_new_uint64(devc->limit_samples);
 354                         break;
 355                 case SR_CONF_CONN:
 356                         if (!sdi->conn)
 357                                 return SR_ERR_ARG;
 358                         usb = sdi->conn;
 359                         if (usb->address == 255)
 360                                 /* Device still needs to re-enumerate after firmware
 361                                  * upload, so we don't know its (future) address. */
 362                                 return SR_ERR;
 363                         *data = g_variant_new_printf("%d.%d", usb->bus, usb->address);
 364                         break;
 365                 default:
 366                         return SR_ERR_NA;
 367                 }
 368         } else {
 369                 if (sdi->channel_groups->data == cg)
 370                         ch_idx = 0;
 371                 else if (sdi->channel_groups->next->data == cg)
 372                         ch_idx = 1;
 373                 else
 374                         return SR_ERR_ARG;
 375                 switch (key) {
 376                 case SR_CONF_VDIV:
 377                         vdiv = vdivs[devc->voltage[ch_idx]];
 378                         *data = g_variant_new("(tt)", vdiv[0], vdiv[1]);
 379                         break;
 380                 case SR_CONF_COUPLING:
 381                         *data = g_variant_new_string((devc->coupling[ch_idx] \
 382                                         == COUPLING_DC) ? "DC" : "AC");
 383                         break;
 384                 }
 385         }
 386
 387         return SR_OK;
 388 }
 389
 390 static int config_set(uint32_t key, GVariant *data,
 391         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 392 {
 393         struct dev_context *devc;
 394         int ch_idx, idx;
 395
 396         devc = sdi->priv;
 397         if (!cg) {
 398                 switch (key) {
 399                 case SR_CONF_SAMPLERATE:
 400                         devc->samplerate = g_variant_get_uint64(data);
 401                         hantek_6xxx_update_samplerate(sdi);
 402                         break;
 403                 case SR_CONF_LIMIT_MSEC:
 404                         devc->limit_msec = g_variant_get_uint64(data);
 405                         break;
 406                 case SR_CONF_LIMIT_SAMPLES:
 407                         devc->limit_samples = g_variant_get_uint64(data);
 408                         break;
 409                 default:
 410                         return SR_ERR_NA;
 411                 }
 412         } else {
 413                 if (sdi->channel_groups->data == cg)
 414                         ch_idx = 0;
 415                 else if (sdi->channel_groups->next->data == cg)
 416                         ch_idx = 1;
 417                 else
 418                         return SR_ERR_ARG;
 419                 switch (key) {
 420                 case SR_CONF_VDIV:
 421                         if ((idx = std_u64_tuple_idx(data, ARRAY_AND_SIZE(vdivs))) < 0)
 422                                 return SR_ERR_ARG;
 423                         devc->voltage[ch_idx] = idx;
 424                         hantek_6xxx_update_vdiv(sdi);
 425                         break;
 426                 case SR_CONF_COUPLING:
 427                         if ((idx = std_str_idx(data, devc->coupling_vals,
 428                                                 devc->coupling_tab_size)) < 0)
 429                                 return SR_ERR_ARG;
 430                         devc->coupling[ch_idx] = idx;
 431                         break;
 432                 default:
 433                         return SR_ERR_NA;
 434                 }
 435         }
 436
 437         return SR_OK;
 438 }
 439
 440 static int config_list(uint32_t key, GVariant **data,
 441         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 442 {
 443         struct dev_context *devc;
 444
 445         devc = (sdi) ? sdi->priv : NULL;
 446
 447         if (!cg) {
 448                 switch (key) {
 449                 case SR_CONF_SCAN_OPTIONS:
 450                 case SR_CONF_DEVICE_OPTIONS:
 451                         return STD_CONFIG_LIST(key, data, sdi, cg, scanopts, drvopts, devopts);
 452                 case SR_CONF_SAMPLERATE:
 453                         *data = std_gvar_samplerates(ARRAY_AND_SIZE(samplerates));
 454                         break;
 455                 default:
 456                         return SR_ERR_NA;
 457                 }
 458         } else {
 459                 switch (key) {
 460                 case SR_CONF_DEVICE_OPTIONS:
 461                         *data = std_gvar_array_u32(ARRAY_AND_SIZE(devopts_cg));
 462                         break;
 463                 case SR_CONF_COUPLING:
 464                         if (!devc)
 465                                 return SR_ERR_ARG;
 466                         *data = g_variant_new_strv(devc->coupling_vals, devc->coupling_tab_size);
 467                         break;
 468                 case SR_CONF_VDIV:
 469                         *data = std_gvar_tuple_array(ARRAY_AND_SIZE(vdivs));
 470                         break;
 471                 default:
 472                         return SR_ERR_NA;
 473                 }
 474         }
 475
 476         return SR_OK;
 477 }
 478
 479 /* Minimise data amount for limit_samples and limit_msec limits. */
 480 static uint32_t data_amount(const struct sr_dev_inst *sdi)
 481 {
 482         struct dev_context *devc = sdi->priv;
 483         uint32_t data_left, data_left_2, i;
 484         int32_t time_left;
 485
 486         if (devc->limit_msec) {
 487                 time_left = devc->limit_msec - (g_get_monotonic_time() - devc->aq_started) / 1000;
 488                 data_left = devc->samplerate * MAX(time_left, 0) * NUM_CHANNELS / 1000;
 489         } else if (devc->limit_samples) {
 490                 data_left = (devc->limit_samples - devc->samp_received) * NUM_CHANNELS;
 491         } else {
 492                 data_left = devc->samplerate * NUM_CHANNELS;
 493         }
 494
 495         /* Round up to nearest power of two. */
 496         for (i = MIN_PACKET_SIZE; i < data_left; i *= 2)
 497                 ;
 498         data_left_2 = i;
 499
 500         sr_spew("data_amount: %u (rounded to power of 2: %u)", data_left, data_left_2);
 501
 502         return data_left_2;
 503 }
 504
 505 static void send_chunk(struct sr_dev_inst *sdi, unsigned char *buf,
 506                 int num_samples)
 507 {
 508         struct sr_datafeed_packet packet;
 509         struct sr_datafeed_analog analog;
 510         struct sr_analog_encoding encoding;
 511         struct sr_analog_meaning meaning;
 512         struct sr_analog_spec spec;
 513         struct dev_context *devc = sdi->priv;
 514         GSList *channels = devc->enabled_channels;
 515
 516         const float ch_bit[] = { RANGE(0) / 255, RANGE(1) / 255 };
 517         const float ch_center[] = { RANGE(0) / 2, RANGE(1) / 2 };
 518
 519         sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
 520
 521         packet.type = SR_DF_ANALOG;
 522         packet.payload = &analog;
 523
 524         analog.num_samples = num_samples;
 525         analog.meaning->mq = SR_MQ_VOLTAGE;
 526         analog.meaning->unit = SR_UNIT_VOLT;
 527         analog.meaning->mqflags = 0;
 528
 529         analog.data = g_try_malloc(num_samples * sizeof(float));
 530         if (!analog.data) {
 531                 sr_err("Analog data buffer malloc failed.");
 532                 devc->dev_state = STOPPING;
 533                 return;
 534         }
 535
 536         for (int ch = 0; ch < NUM_CHANNELS; ch++) {
 537                 if (!devc->ch_enabled[ch])
 538                         continue;
 539
 540                 float vdivlog = log10f(ch_bit[ch]);
 541                 int digits = -(int)vdivlog + (vdivlog < 0.0);
 542                 analog.encoding->digits = digits;
 543                 analog.spec->spec_digits = digits;
 544                 analog.meaning->channels = g_slist_append(NULL, channels->data);
 545
 546                 for (int i = 0; i < num_samples; i++) {
 547                         /*
 548                          * The device always sends data for both channels. If a channel
 549                          * is disabled, it contains a copy of the enabled channel's
 550                          * data. However, we only send the requested channels to
 551                          * the bus.
 552                          *
 553                          * Voltage values are encoded as a value 0-255, where the
 554                          * value is a point in the range represented by the vdiv
 555                          * setting. There are 10 vertical divs, so e.g. 500mV/div
 556                          * represents 5V peak-to-peak where 0 = -2.5V and 255 = +2.5V.
 557                          */
 558                         ((float *)analog.data)[i] = ch_bit[ch] * *(buf + i * 2 + ch) - ch_center[ch];
 559                 }
 560
 561                 sr_session_send(sdi, &packet);
 562                 g_slist_free(analog.meaning->channels);
 563
 564                 channels = channels->next;
 565         }
 566         g_free(analog.data);
 567 }
 568
 569 /*
 570  * Called by libusb (as triggered by handle_event()) when a transfer comes in.
 571  * Only channel data comes in asynchronously, and all transfers for this are
 572  * queued up beforehand, so this just needs to chuck the incoming data onto
 573  * the libsigrok session bus.
 574  */
 575 static void LIBUSB_CALL receive_transfer(struct libusb_transfer *transfer)
 576 {
 577         struct sr_dev_inst *sdi;
 578         struct dev_context *devc;
 579
 580         sdi = transfer->user_data;
 581         devc = sdi->priv;
 582
 583         if (devc->dev_state == FLUSH) {
 584                 g_free(transfer->buffer);
 585                 libusb_free_transfer(transfer);
 586                 devc->dev_state = CAPTURE;
 587                 devc->aq_started = g_get_monotonic_time();
 588                 read_channel(sdi, data_amount(sdi));
 589                 return;
 590         }
 591
 592         if (devc->dev_state != CAPTURE)
 593                 return;
 594
 595         sr_spew("receive_transfer(): calculated samplerate == %" PRIu64 "ks/s",
 596                 (uint64_t)(transfer->actual_length * 1000 /
 597                 (g_get_monotonic_time() - devc->read_start_ts + 1) /
 598                 NUM_CHANNELS));
 599
 600         sr_spew("receive_transfer(): status %s received %d bytes.",
 601                 libusb_error_name(transfer->status), transfer->actual_length);
 602
 603         if (transfer->actual_length == 0)
 604                 /* Nothing to send to the bus. */
 605                 return;
 606
 607         unsigned samples_received = transfer->actual_length / NUM_CHANNELS;
 608         send_chunk(sdi, transfer->buffer, samples_received);
 609         devc->samp_received += samples_received;
 610
 611         g_free(transfer->buffer);
 612         libusb_free_transfer(transfer);
 613
 614         if (devc->limit_samples && devc->samp_received >= devc->limit_samples) {
 615                 sr_info("Requested number of samples reached, stopping. %"
 616                         PRIu64 " <= %" PRIu64, devc->limit_samples,
 617                         devc->samp_received);
 618                 sr_dev_acquisition_stop(sdi);
 619         } else if (devc->limit_msec && (g_get_monotonic_time() -
 620                         devc->aq_started) / 1000 >= devc->limit_msec) {
 621                 sr_info("Requested time limit reached, stopping. %d <= %d",
 622                         (uint32_t)devc->limit_msec,
 623                         (uint32_t)(g_get_monotonic_time() - devc->aq_started) / 1000);
 624                 sr_dev_acquisition_stop(sdi);
 625         } else {
 626                 read_channel(sdi, data_amount(sdi));
 627         }
 628 }
 629
 630 static int read_channel(const struct sr_dev_inst *sdi, uint32_t amount)
 631 {
 632         int ret;
 633         struct dev_context *devc;
 634
 635         devc = sdi->priv;
 636
 637         amount = MIN(amount, MAX_PACKET_SIZE);
 638         ret = hantek_6xxx_get_channeldata(sdi, receive_transfer, amount);
 639         devc->read_start_ts = g_get_monotonic_time();
 640         devc->read_data_amount = amount;
 641
 642         return ret;
 643 }
 644
 645 static int handle_event(int fd, int revents, void *cb_data)
 646 {
 647         const struct sr_dev_inst *sdi;
 648         struct timeval tv;
 649         struct sr_dev_driver *di;
 650         struct dev_context *devc;
 651         struct drv_context *drvc;
 652
 653         (void)fd;
 654         (void)revents;
 655
 656         sdi = cb_data;
 657         di = sdi->driver;
 658         drvc = di->context;
 659         devc = sdi->priv;
 660
 661         /* Always handle pending libusb events. */
 662         tv.tv_sec = tv.tv_usec = 0;
 663         libusb_handle_events_timeout(drvc->sr_ctx->libusb_ctx, &tv);
 664
 665         if (devc->dev_state == STOPPING) {
 666                 /* We've been told to wind up the acquisition. */
 667                 sr_dbg("Stopping acquisition.");
 668
 669                 hantek_6xxx_stop_data_collecting(sdi);
 670                 /*
 671                  * TODO: Doesn't really cancel pending transfers so they might
 672                  * come in after SR_DF_END is sent.
 673                  */
 674                 usb_source_remove(sdi->session, drvc->sr_ctx);
 675
 676                 std_session_send_df_end(sdi);
 677
 678                 devc->dev_state = IDLE;
 679
 680                 return TRUE;
 681         }
 682
 683         return TRUE;
 684 }
 685
 686 static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 687 {
 688         struct dev_context *devc;
 689         struct sr_dev_driver *di = sdi->driver;
 690         struct drv_context *drvc = di->context;
 691
 692         devc = sdi->priv;
 693
 694         if (configure_channels(sdi) != SR_OK) {
 695                 sr_err("Failed to configure channels.");
 696                 return SR_ERR;
 697         }
 698
 699         if (hantek_6xxx_init(sdi) != SR_OK)
 700                 return SR_ERR;
 701
 702         std_session_send_df_header(sdi);
 703
 704         devc->samp_received = 0;
 705         devc->dev_state = FLUSH;
 706
 707         usb_source_add(sdi->session, drvc->sr_ctx, TICK,
 708                        handle_event, (void *)sdi);
 709
 710         hantek_6xxx_start_data_collecting(sdi);
 711
 712         read_channel(sdi, FLUSH_PACKET_SIZE);
 713
 714         return SR_OK;
 715 }
 716
 717 static int dev_acquisition_stop(struct sr_dev_inst *sdi)
 718 {
 719         struct dev_context *devc;
 720
 721         devc = sdi->priv;
 722         devc->dev_state = STOPPING;
 723
 724         g_free(devc->sample_buf);
 725         devc->sample_buf = NULL;
 726
 727         return SR_OK;
 728 }
 729
 730 static struct sr_dev_driver hantek_6xxx_driver_info = {
 731         .name = "hantek-6xxx",
 732         .longname = "Hantek 6xxx",
 733         .api_version = 1,
 734         .init = std_init,
 735         .cleanup = std_cleanup,
 736         .scan = scan,
 737         .dev_list = std_dev_list,
 738         .dev_clear = dev_clear,
 739         .config_get = config_get,
 740         .config_set = config_set,
 741         .config_list = config_list,
 742         .dev_open = dev_open,
 743         .dev_close = dev_close,
 744         .dev_acquisition_start = dev_acquisition_start,
 745         .dev_acquisition_stop = dev_acquisition_stop,
 746         .context = NULL,
 747 };
 748 SR_REGISTER_DEV_DRIVER(hantek_6xxx_driver_info);