hardware/openbench-logic-sniffer/api.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 #include <libserialport.h>
  22
  23 #define SERIALCOMM "115200/8n1"
  24
  25 static const int32_t hwopts[] = {
  26         SR_CONF_CONN,
  27         SR_CONF_SERIALCOMM,
  28 };
  29
  30 static const int32_t hwcaps[] = {
  31         SR_CONF_LOGIC_ANALYZER,
  32         SR_CONF_SAMPLERATE,
  33         SR_CONF_TRIGGER_TYPE,
  34         SR_CONF_CAPTURE_RATIO,
  35         SR_CONF_LIMIT_SAMPLES,
  36         SR_CONF_EXTERNAL_CLOCK,
  37         SR_CONF_PATTERN_MODE,
  38         SR_CONF_SWAP,
  39         SR_CONF_RLE,
  40 };
  41
  42 #define STR_PATTERN_NONE     "None"
  43 #define STR_PATTERN_EXTERNAL "External"
  44 #define STR_PATTERN_INTERNAL "Internal"
  45
  46 /* Supported methods of test pattern outputs */
  47 enum {
  48         /**
  49          * Capture pins 31:16 (unbuffered wing) output a test pattern
  50          * that can captured on pins 0:15.
  51          */
  52         PATTERN_EXTERNAL,
  53
  54         /** Route test pattern internally to capture buffer. */
  55         PATTERN_INTERNAL,
  56 };
  57
  58 static const char *patterns[] = {
  59         STR_PATTERN_NONE,
  60         STR_PATTERN_EXTERNAL,
  61         STR_PATTERN_INTERNAL,
  62 };
  63
  64 /* Channels are numbered 0-31 (on the PCB silkscreen). */
  65 SR_PRIV const char *ols_channel_names[NUM_CHANNELS + 1] = {
  66         "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12",
  67         "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23",
  68         "24", "25", "26", "27", "28", "29", "30", "31",
  69         NULL,
  70 };
  71
  72 /* Default supported samplerates, can be overridden by device metadata. */
  73 static const uint64_t samplerates[] = {
  74         SR_HZ(10),
  75         SR_MHZ(200),
  76         SR_HZ(1),
  77 };
  78
  79 SR_PRIV struct sr_dev_driver ols_driver_info;
  80 static struct sr_dev_driver *di = &ols_driver_info;
  81
  82 static int init(struct sr_context *sr_ctx)
  83 {
  84         return std_init(sr_ctx, di, LOG_PREFIX);
  85 }
  86
  87 static GSList *scan(GSList *options)
  88 {
  89         struct sr_config *src;
  90         struct sr_dev_inst *sdi;
  91         struct drv_context *drvc;
  92         struct dev_context *devc;
  93         struct sr_channel *ch;
  94         struct sr_serial_dev_inst *serial;
  95         GPollFD probefd;
  96         GSList *l, *devices;
  97         int ret, i;
  98         const char *conn, *serialcomm;
  99         char buf[8];
 100
 101         drvc = di->priv;
 102
 103         devices = NULL;
 104
 105         conn = serialcomm = NULL;
 106         for (l = options; l; l = l->next) {
 107                 src = l->data;
 108                 switch (src->key) {
 109                 case SR_CONF_CONN:
 110                         conn = g_variant_get_string(src->data, NULL);
 111                         break;
 112                 case SR_CONF_SERIALCOMM:
 113                         serialcomm = g_variant_get_string(src->data, NULL);
 114                         break;
 115                 }
 116         }
 117         if (!conn)
 118                 return NULL;
 119
 120         if (serialcomm == NULL)
 121                 serialcomm = SERIALCOMM;
 122
 123         if (!(serial = sr_serial_dev_inst_new(conn, serialcomm)))
 124                 return NULL;
 125
 126         /* The discovery procedure is like this: first send the Reset
 127          * command (0x00) 5 times, since the device could be anywhere
 128          * in a 5-byte command. Then send the ID command (0x02).
 129          * If the device responds with 4 bytes ("OLS1" or "SLA1"), we
 130          * have a match.
 131          */
 132         sr_info("Probing %s.", conn);
 133         if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
 134                 return NULL;
 135
 136         ret = SR_OK;
 137         for (i = 0; i < 5; i++) {
 138                 if ((ret = send_shortcommand(serial, CMD_RESET)) != SR_OK) {
 139                         sr_err("Port %s is not writable.", conn);
 140                         break;
 141                 }
 142         }
 143         if (ret != SR_OK) {
 144                 serial_close(serial);
 145                 sr_err("Could not use port %s. Quitting.", conn);
 146                 return NULL;
 147         }
 148         send_shortcommand(serial, CMD_ID);
 149
 150         /* Wait 10ms for a response. */
 151         g_usleep(10000);
 152
 153         sp_get_port_handle(serial->data, &probefd.fd);
 154         probefd.events = G_IO_IN;
 155         g_poll(&probefd, 1, 1);
 156
 157         if (probefd.revents != G_IO_IN)
 158                 return NULL;
 159         if (serial_read_blocking(serial, buf, 4) != 4)
 160                 return NULL;
 161         if (strncmp(buf, "1SLO", 4) && strncmp(buf, "1ALS", 4))
 162                 return NULL;
 163
 164         /* Definitely using the OLS protocol, check if it supports
 165          * the metadata command.
 166          */
 167         send_shortcommand(serial, CMD_METADATA);
 168         if (g_poll(&probefd, 1, 10) > 0) {
 169                 /* Got metadata. */
 170                 sdi = get_metadata(serial);
 171                 sdi->index = 0;
 172                 devc = sdi->priv;
 173         } else {
 174                 /* Not an OLS -- some other board that uses the sump protocol. */
 175                 sr_info("Device does not support metadata.");
 176                 sdi = sr_dev_inst_new(0, SR_ST_INACTIVE,
 177                                 "Sump", "Logic Analyzer", "v1.0");
 178                 sdi->driver = di;
 179                 for (i = 0; i < 32; i++) {
 180                         if (!(ch = sr_channel_new(i, SR_CHANNEL_LOGIC, TRUE,
 181                                         ols_channel_names[i])))
 182                                 return 0;
 183                         sdi->channels = g_slist_append(sdi->channels, ch);
 184                 }
 185                 devc = ols_dev_new();
 186                 sdi->priv = devc;
 187         }
 188         /* Configure samplerate and divider. */
 189         if (ols_set_samplerate(sdi, DEFAULT_SAMPLERATE) != SR_OK)
 190                 sr_dbg("Failed to set default samplerate (%"PRIu64").",
 191                                 DEFAULT_SAMPLERATE);
 192         /* Clear trigger masks, values and stages. */
 193         ols_configure_channels(sdi);
 194         sdi->inst_type = SR_INST_SERIAL;
 195         sdi->conn = serial;
 196
 197         drvc->instances = g_slist_append(drvc->instances, sdi);
 198         devices = g_slist_append(devices, sdi);
 199
 200         serial_close(serial);
 201
 202         return devices;
 203 }
 204
 205 static GSList *dev_list(void)
 206 {
 207         return ((struct drv_context *)(di->priv))->instances;
 208 }
 209
 210 static int cleanup(void)
 211 {
 212         return std_dev_clear(di, NULL);
 213 }
 214
 215 static int config_get(int id, GVariant **data, const struct sr_dev_inst *sdi,
 216                 const struct sr_channel_group *cg)
 217 {
 218         struct dev_context *devc;
 219
 220         (void)cg;
 221
 222         if (!sdi)
 223                 return SR_ERR_ARG;
 224
 225         devc = sdi->priv;
 226         switch (id) {
 227         case SR_CONF_SAMPLERATE:
 228                 *data = g_variant_new_uint64(devc->cur_samplerate);
 229                 break;
 230         case SR_CONF_CAPTURE_RATIO:
 231                 *data = g_variant_new_uint64(devc->capture_ratio);
 232                 break;
 233         case SR_CONF_LIMIT_SAMPLES:
 234                 *data = g_variant_new_uint64(devc->limit_samples);
 235                 break;
 236         case SR_CONF_PATTERN_MODE:
 237                 if (devc->flag_reg & FLAG_EXTERNAL_TEST_MODE)
 238                         *data = g_variant_new_string(STR_PATTERN_EXTERNAL);
 239                 else if (devc->flag_reg & FLAG_INTERNAL_TEST_MODE)
 240                         *data = g_variant_new_string(STR_PATTERN_INTERNAL);
 241                 else
 242                         *data = g_variant_new_string(STR_PATTERN_NONE);
 243                 break;
 244         case SR_CONF_RLE:
 245                 *data = g_variant_new_boolean(devc->flag_reg & FLAG_RLE ? TRUE : FALSE);
 246                 break;
 247         default:
 248                 return SR_ERR_NA;
 249         }
 250
 251         return SR_OK;
 252 }
 253
 254 static int config_set(int id, GVariant *data, const struct sr_dev_inst *sdi,
 255                 const struct sr_channel_group *cg)
 256 {
 257         struct dev_context *devc;
 258         uint16_t flag;
 259         uint64_t tmp_u64;
 260         int ret;
 261         const char *stropt;
 262
 263         (void)cg;
 264
 265         if (sdi->status != SR_ST_ACTIVE)
 266                 return SR_ERR_DEV_CLOSED;
 267
 268         devc = sdi->priv;
 269
 270         switch (id) {
 271         case SR_CONF_SAMPLERATE:
 272                 tmp_u64 = g_variant_get_uint64(data);
 273                 if (tmp_u64 < samplerates[0] || tmp_u64 > samplerates[1])
 274                         return SR_ERR_SAMPLERATE;
 275                 ret = ols_set_samplerate(sdi, g_variant_get_uint64(data));
 276                 break;
 277         case SR_CONF_LIMIT_SAMPLES:
 278                 tmp_u64 = g_variant_get_uint64(data);
 279                 if (tmp_u64 < MIN_NUM_SAMPLES)
 280                         return SR_ERR;
 281                 devc->limit_samples = tmp_u64;
 282                 ret = SR_OK;
 283                 break;
 284         case SR_CONF_CAPTURE_RATIO:
 285                 devc->capture_ratio = g_variant_get_uint64(data);
 286                 if (devc->capture_ratio < 0 || devc->capture_ratio > 100) {
 287                         devc->capture_ratio = 0;
 288                         ret = SR_ERR;
 289                 } else
 290                         ret = SR_OK;
 291                 break;
 292         case SR_CONF_EXTERNAL_CLOCK:
 293                 if (g_variant_get_boolean(data)) {
 294                         sr_info("Enabling external clock.");
 295                         devc->flag_reg |= FLAG_CLOCK_EXTERNAL;
 296                 } else {
 297                         sr_info("Disabled external clock.");
 298                         devc->flag_reg &= ~FLAG_CLOCK_EXTERNAL;
 299                 }
 300                 ret = SR_OK;
 301                 break;
 302         case SR_CONF_PATTERN_MODE:
 303                 stropt = g_variant_get_string(data, NULL);
 304                 ret = SR_OK;
 305                 flag = 0xffff;
 306                 if (!strcmp(stropt, STR_PATTERN_NONE)) {
 307                         sr_info("Disabling test modes.");
 308                         flag = 0x0000;
 309                 }else if (!strcmp(stropt, STR_PATTERN_INTERNAL)) {
 310                         sr_info("Enabling internal test mode.");
 311                         flag = FLAG_INTERNAL_TEST_MODE;
 312                 } else if (!strcmp(stropt, STR_PATTERN_EXTERNAL)) {
 313                         sr_info("Enabling external test mode.");
 314                         flag = FLAG_EXTERNAL_TEST_MODE;
 315                 } else {
 316                         ret = SR_ERR;
 317                 }
 318                 if (flag != 0xffff) {
 319                         devc->flag_reg &= ~(FLAG_INTERNAL_TEST_MODE | FLAG_EXTERNAL_TEST_MODE);
 320                         devc->flag_reg |= flag;
 321                 }
 322                 break;
 323         case SR_CONF_SWAP:
 324                 if (g_variant_get_boolean(data)) {
 325                         sr_info("Enabling channel swapping.");
 326                         devc->flag_reg |= FLAG_SWAP_CHANNELS;
 327                 } else {
 328                         sr_info("Disabling channel swapping.");
 329                         devc->flag_reg &= ~FLAG_SWAP_CHANNELS;
 330                 }
 331                 ret = SR_OK;
 332                 break;
 333
 334         case SR_CONF_RLE:
 335                 if (g_variant_get_boolean(data)) {
 336                         sr_info("Enabling RLE.");
 337                         devc->flag_reg |= FLAG_RLE;
 338                 } else {
 339                         sr_info("Disabling RLE.");
 340                         devc->flag_reg &= ~FLAG_RLE;
 341                 }
 342                 ret = SR_OK;
 343                 break;
 344         default:
 345                 ret = SR_ERR_NA;
 346         }
 347
 348         return ret;
 349 }
 350
 351 static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi,
 352                 const struct sr_channel_group *cg)
 353 {
 354         struct dev_context *devc;
 355         GVariant *gvar, *grange[2];
 356         GVariantBuilder gvb;
 357         int num_channels, i;
 358
 359         (void)cg;
 360
 361         switch (key) {
 362         case SR_CONF_SCAN_OPTIONS:
 363                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
 364                                 hwopts, ARRAY_SIZE(hwopts), sizeof(int32_t));
 365                 break;
 366         case SR_CONF_DEVICE_OPTIONS:
 367                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
 368                                 hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
 369                 break;
 370         case SR_CONF_SAMPLERATE:
 371                 g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
 372                 gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"), samplerates,
 373                                 ARRAY_SIZE(samplerates), sizeof(uint64_t));
 374                 g_variant_builder_add(&gvb, "{sv}", "samplerate-steps", gvar);
 375                 *data = g_variant_builder_end(&gvb);
 376                 break;
 377         case SR_CONF_TRIGGER_TYPE:
 378                 *data = g_variant_new_string(TRIGGER_TYPE);
 379                 break;
 380         case SR_CONF_PATTERN_MODE:
 381                 *data = g_variant_new_strv(patterns, ARRAY_SIZE(patterns));
 382                 break;
 383         case SR_CONF_LIMIT_SAMPLES:
 384                 if (!sdi)
 385                         return SR_ERR_ARG;
 386                 devc = sdi->priv;
 387                 if (devc->flag_reg & FLAG_RLE)
 388                         return SR_ERR_NA;
 389                 if (devc->max_samples == 0)
 390                         /* Device didn't specify sample memory size in metadata. */
 391                         return SR_ERR_NA;
 392                 /*
 393                  * Channel groups are turned off if no channels in that group are
 394                  * enabled, making more room for samples for the enabled group.
 395                 */
 396                 ols_configure_channels(sdi);
 397                 num_channels = 0;
 398                 for (i = 0; i < 4; i++) {
 399                         if (devc->channel_mask & (0xff << (i * 8)))
 400                                 num_channels++;
 401                 }
 402                 if (num_channels == 0) {
 403                         /* This can happen, but shouldn't cause too much drama.
 404                          * However we can't continue because the code below would
 405                          * divide by zero. */
 406                         break;
 407                 }
 408                 grange[0] = g_variant_new_uint64(MIN_NUM_SAMPLES);
 409                 grange[1] = g_variant_new_uint64(devc->max_samples / num_channels);
 410                 *data = g_variant_new_tuple(grange, 2);
 411                 break;
 412         default:
 413                 return SR_ERR_NA;
 414         }
 415
 416         return SR_OK;
 417 }
 418
 419 static int set_trigger(const struct sr_dev_inst *sdi, int stage)
 420 {
 421         struct dev_context *devc;
 422         struct sr_serial_dev_inst *serial;
 423         uint8_t cmd, arg[4];
 424
 425         devc = sdi->priv;
 426         serial = sdi->conn;
 427
 428         cmd = CMD_SET_TRIGGER_MASK + stage * 4;
 429         arg[0] = devc->trigger_mask[stage] & 0xff;
 430         arg[1] = (devc->trigger_mask[stage] >> 8) & 0xff;
 431         arg[2] = (devc->trigger_mask[stage] >> 16) & 0xff;
 432         arg[3] = (devc->trigger_mask[stage] >> 24) & 0xff;
 433         if (send_longcommand(serial, cmd, arg) != SR_OK)
 434                 return SR_ERR;
 435
 436         cmd = CMD_SET_TRIGGER_VALUE + stage * 4;
 437         arg[0] = devc->trigger_value[stage] & 0xff;
 438         arg[1] = (devc->trigger_value[stage] >> 8) & 0xff;
 439         arg[2] = (devc->trigger_value[stage] >> 16) & 0xff;
 440         arg[3] = (devc->trigger_value[stage] >> 24) & 0xff;
 441         if (send_longcommand(serial, cmd, arg) != SR_OK)
 442                 return SR_ERR;
 443
 444         cmd = CMD_SET_TRIGGER_CONFIG + stage * 4;
 445         arg[0] = arg[1] = arg[3] = 0x00;
 446         arg[2] = stage;
 447         if (stage == devc->num_stages)
 448                 /* Last stage, fire when this one matches. */
 449                 arg[3] |= TRIGGER_START;
 450         if (send_longcommand(serial, cmd, arg) != SR_OK)
 451                 return SR_ERR;
 452
 453         return SR_OK;
 454 }
 455
 456 static int dev_acquisition_start(const struct sr_dev_inst *sdi,
 457                 void *cb_data)
 458 {
 459         struct dev_context *devc;
 460         struct sr_serial_dev_inst *serial;
 461         uint16_t samplecount, readcount, delaycount;
 462         uint8_t changrp_mask, arg[4];
 463         int num_channels;
 464         int ret, i;
 465
 466         if (sdi->status != SR_ST_ACTIVE)
 467                 return SR_ERR_DEV_CLOSED;
 468
 469         devc = sdi->priv;
 470         serial = sdi->conn;
 471
 472         if (ols_configure_channels(sdi) != SR_OK) {
 473                 sr_err("Failed to configure channels.");
 474                 return SR_ERR;
 475         }
 476
 477         /*
 478          * Enable/disable channel groups in the flag register according to the
 479          * channel mask. Calculate this here, because num_channels is needed
 480          * to limit readcount.
 481          */
 482         changrp_mask = 0;
 483         num_channels = 0;
 484         for (i = 0; i < 4; i++) {
 485                 if (devc->channel_mask & (0xff << (i * 8))) {
 486                         changrp_mask |= (1 << i);
 487                         num_channels++;
 488                 }
 489         }
 490
 491         /*
 492          * Limit readcount to prevent reading past the end of the hardware
 493          * buffer.
 494          */
 495         samplecount = MIN(devc->max_samples / num_channels, devc->limit_samples);
 496         readcount = samplecount / 4;
 497
 498         /* Rather read too many samples than too few. */
 499         if (samplecount % 4 != 0)
 500                 readcount++;
 501
 502         /* Basic triggers. */
 503         if (devc->trigger_mask[0] != 0x00000000) {
 504                 /* At least one channel has a trigger on it. */
 505                 delaycount = readcount * (1 - devc->capture_ratio / 100.0);
 506                 devc->trigger_at = (readcount - delaycount) * 4 - devc->num_stages;
 507                 for (i = 0; i <= devc->num_stages; i++) {
 508                         sr_dbg("Setting stage %d trigger.", i);
 509                         if ((ret = set_trigger(sdi, i)) != SR_OK)
 510                                 return ret;
 511                 }
 512         } else {
 513                 /* No triggers configured, force trigger on first stage. */
 514                 sr_dbg("Forcing trigger at stage 0.");
 515                 if ((ret = set_trigger(sdi, 0)) != SR_OK)
 516                         return ret;
 517                 delaycount = readcount;
 518         }
 519
 520         /* Samplerate. */
 521         sr_dbg("Setting samplerate to %" PRIu64 "Hz (divider %u)",
 522                         devc->cur_samplerate, devc->cur_samplerate_divider);
 523         arg[0] = devc->cur_samplerate_divider & 0xff;
 524         arg[1] = (devc->cur_samplerate_divider & 0xff00) >> 8;
 525         arg[2] = (devc->cur_samplerate_divider & 0xff0000) >> 16;
 526         arg[3] = 0x00;
 527         if (send_longcommand(serial, CMD_SET_DIVIDER, arg) != SR_OK)
 528                 return SR_ERR;
 529
 530         /* Send sample limit and pre/post-trigger capture ratio. */
 531         sr_dbg("Setting sample limit %d, trigger point at %d",
 532                         (readcount - 1) * 4, (delaycount - 1) * 4);
 533         arg[0] = ((readcount - 1) & 0xff);
 534         arg[1] = ((readcount - 1) & 0xff00) >> 8;
 535         arg[2] = ((delaycount - 1) & 0xff);
 536         arg[3] = ((delaycount - 1) & 0xff00) >> 8;
 537         if (send_longcommand(serial, CMD_CAPTURE_SIZE, arg) != SR_OK)
 538                 return SR_ERR;
 539
 540         /* Flag register. */
 541         sr_dbg("Setting intpat %s, extpat %s, RLE %s, noise_filter %s, demux %s",
 542                         devc->flag_reg & FLAG_INTERNAL_TEST_MODE ? "on": "off",
 543                         devc->flag_reg & FLAG_EXTERNAL_TEST_MODE ? "on": "off",
 544                         devc->flag_reg & FLAG_RLE ? "on" : "off",
 545                         devc->flag_reg & FLAG_FILTER ? "on": "off",
 546                         devc->flag_reg & FLAG_DEMUX ? "on" : "off");
 547         /* 1 means "disable channel". */
 548         devc->flag_reg |= ~(changrp_mask << 2) & 0x3c;
 549         arg[0] = devc->flag_reg & 0xff;
 550         arg[1] = devc->flag_reg >> 8;
 551         arg[2] = arg[3] = 0x00;
 552         if (send_longcommand(serial, CMD_SET_FLAGS, arg) != SR_OK)
 553                 return SR_ERR;
 554
 555         /* Start acquisition on the device. */
 556         if (send_shortcommand(serial, CMD_RUN) != SR_OK)
 557                 return SR_ERR;
 558
 559         /* Reset all operational states. */
 560         devc->rle_count = devc->num_transfers = 0;
 561         devc->num_samples = devc->num_bytes = 0;
 562         devc->cnt_bytes = devc->cnt_samples = devc->cnt_samples_rle = 0;
 563         memset(devc->sample, 0, 4);
 564
 565         /* Send header packet to the session bus. */
 566         std_session_send_df_header(cb_data, LOG_PREFIX);
 567
 568         serial_source_add(serial, G_IO_IN, -1, ols_receive_data, cb_data);
 569
 570         return SR_OK;
 571 }
 572
 573 static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 574 {
 575         (void)cb_data;
 576
 577         abort_acquisition(sdi);
 578
 579         return SR_OK;
 580 }
 581
 582 SR_PRIV struct sr_dev_driver ols_driver_info = {
 583         .name = "ols",
 584         .longname = "Openbench Logic Sniffer",
 585         .api_version = 1,
 586         .init = init,
 587         .cleanup = cleanup,
 588         .scan = scan,
 589         .dev_list = dev_list,
 590         .dev_clear = NULL,
 591         .config_get = config_get,
 592         .config_set = config_set,
 593         .config_list = config_list,
 594         .dev_open = std_serial_dev_open,
 595         .dev_close = std_serial_dev_close,
 596         .dev_acquisition_start = dev_acquisition_start,
 597         .dev_acquisition_stop = dev_acquisition_stop,
 598         .priv = NULL,
 599 };