src/hardware/asix-sigma/api.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2010-2012 Håvard Espeland <gus@ping.uio.no>,
   5  * Copyright (C) 2010 Martin Stensgård <mastensg@ping.uio.no>
   6  * Copyright (C) 2010 Carl Henrik Lunde <chlunde@ping.uio.no>
   7  * Copyright (C) 2020 Gerhard Sittig <gerhard.sittig@gmx.net>
   8  *
   9  * This program is free software: you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation, either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include <config.h>
  24 #include "protocol.h"
  25
  26 /*
  27  * Channels are labelled 1-16, see this vendor's image of the cable:
  28  * http://tools.asix.net/img/sigma_sigmacab_pins_720.jpg (TI/TO are
  29  * additional trigger in/out signals).
  30  */
  31 static const char *channel_names[] = {
  32         "1", "2", "3", "4", "5", "6", "7", "8",
  33         "9", "10", "11", "12", "13", "14", "15", "16",
  34 };
  35
  36 static const uint32_t scanopts[] = {
  37         SR_CONF_CONN,
  38         SR_CONF_PROBE_NAMES,
  39 };
  40
  41 static const uint32_t drvopts[] = {
  42         SR_CONF_LOGIC_ANALYZER,
  43 };
  44
  45 static const uint32_t devopts[] = {
  46         SR_CONF_LIMIT_MSEC | SR_CONF_GET | SR_CONF_SET,
  47         SR_CONF_LIMIT_SAMPLES | SR_CONF_GET | SR_CONF_SET,
  48         SR_CONF_CONN | SR_CONF_GET,
  49         SR_CONF_SAMPLERATE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
  50         SR_CONF_EXTERNAL_CLOCK | SR_CONF_GET | SR_CONF_SET,
  51         SR_CONF_EXTERNAL_CLOCK_SOURCE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
  52         SR_CONF_CLOCK_EDGE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
  53         SR_CONF_TRIGGER_MATCH | SR_CONF_LIST,
  54         SR_CONF_CAPTURE_RATIO | SR_CONF_GET | SR_CONF_SET,
  55         /* Consider SR_CONF_TRIGGER_PATTERN (SR_T_STRING, GET/SET) support. */
  56 };
  57
  58 static const char *ext_clock_edges[] = {
  59         [SIGMA_CLOCK_EDGE_RISING] = "rising",
  60         [SIGMA_CLOCK_EDGE_FALLING] = "falling",
  61         [SIGMA_CLOCK_EDGE_EITHER] = "either",
  62 };
  63
  64 static const int32_t trigger_matches[] = {
  65         SR_TRIGGER_ZERO,
  66         SR_TRIGGER_ONE,
  67         SR_TRIGGER_RISING,
  68         SR_TRIGGER_FALLING,
  69 };
  70
  71 static void clear_helper(struct dev_context *devc)
  72 {
  73         (void)sigma_force_close(devc);
  74 }
  75
  76 static int dev_clear(const struct sr_dev_driver *di)
  77 {
  78         return std_dev_clear_with_callback(di,
  79                 (std_dev_clear_callback)clear_helper);
  80 }
  81
  82 static gboolean bus_addr_in_devices(int bus, int addr, GSList *devs)
  83 {
  84         struct sr_usb_dev_inst *usb;
  85
  86         for (/* EMPTY */; devs; devs = devs->next) {
  87                 usb = devs->data;
  88                 if (usb->bus == bus && usb->address == addr)
  89                         return TRUE;
  90         }
  91
  92         return FALSE;
  93 }
  94
  95 static gboolean known_vid_pid(const struct libusb_device_descriptor *des)
  96 {
  97         gboolean is_sigma, is_omega;
  98
  99         if (des->idVendor != USB_VENDOR_ASIX)
 100                 return FALSE;
 101         is_sigma = des->idProduct == USB_PRODUCT_SIGMA;
 102         is_omega = des->idProduct == USB_PRODUCT_OMEGA;
 103         if (!is_sigma && !is_omega)
 104                 return FALSE;
 105         return TRUE;
 106 }
 107
 108 static GSList *scan(struct sr_dev_driver *di, GSList *options)
 109 {
 110         struct drv_context *drvc;
 111         libusb_context *usbctx;
 112         const char *conn;
 113         const char *probe_names;
 114         GSList *l, *conn_devices;
 115         struct sr_config *src;
 116         GSList *devices;
 117         libusb_device **devlist, *devitem;
 118         int bus, addr;
 119         struct libusb_device_descriptor des;
 120         struct libusb_device_handle *hdl;
 121         int ret;
 122         char conn_id[20];
 123         char serno_txt[16];
 124         char *end;
 125         unsigned long serno_num, serno_pre;
 126         enum asix_device_type dev_type;
 127         const char *dev_text;
 128         struct sr_dev_inst *sdi;
 129         struct dev_context *devc;
 130         size_t devidx, chidx;
 131         size_t count;
 132
 133         drvc = di->context;
 134         usbctx = drvc->sr_ctx->libusb_ctx;
 135
 136         /* Find all devices which match an (optional) conn= spec. */
 137         conn = NULL;
 138         probe_names = NULL;
 139         for (l = options; l; l = l->next) {
 140                 src = l->data;
 141                 switch (src->key) {
 142                 case SR_CONF_CONN:
 143                         conn = g_variant_get_string(src->data, NULL);
 144                         break;
 145                 case SR_CONF_PROBE_NAMES:
 146                         probe_names = g_variant_get_string(src->data, NULL);
 147                         break;
 148                 }
 149         }
 150         conn_devices = NULL;
 151         if (conn)
 152                 conn_devices = sr_usb_find(usbctx, conn);
 153         if (conn && !conn_devices)
 154                 return NULL;
 155
 156         /* Find all ASIX logic analyzers (which match the connection spec). */
 157         devices = NULL;
 158         libusb_get_device_list(usbctx, &devlist);
 159         for (devidx = 0; devlist[devidx]; devidx++) {
 160                 devitem = devlist[devidx];
 161
 162                 /* Check for connection match if a user spec was given. */
 163                 bus = libusb_get_bus_number(devitem);
 164                 addr = libusb_get_device_address(devitem);
 165                 if (conn && !bus_addr_in_devices(bus, addr, conn_devices))
 166                         continue;
 167                 snprintf(conn_id, sizeof(conn_id), "%d.%d", bus, addr);
 168
 169                 /*
 170                  * Check for known VID:PID pairs. Get the serial number,
 171                  * to then derive the device type from it.
 172                  */
 173                 libusb_get_device_descriptor(devitem, &des);
 174                 if (!known_vid_pid(&des))
 175                         continue;
 176                 if (!des.iSerialNumber) {
 177                         sr_warn("Cannot get serial number (index 0).");
 178                         continue;
 179                 }
 180                 ret = libusb_open(devitem, &hdl);
 181                 if (ret < 0) {
 182                         sr_warn("Cannot open USB device %04x.%04x: %s.",
 183                                 des.idVendor, des.idProduct,
 184                                 libusb_error_name(ret));
 185                         continue;
 186                 }
 187                 ret = libusb_get_string_descriptor_ascii(hdl,
 188                         des.iSerialNumber,
 189                         (unsigned char *)serno_txt, sizeof(serno_txt));
 190                 if (ret < 0) {
 191                         sr_warn("Cannot get serial number (%s).",
 192                                 libusb_error_name(ret));
 193                         libusb_close(hdl);
 194                         continue;
 195                 }
 196                 libusb_close(hdl);
 197
 198                 /*
 199                  * All ASIX logic analyzers have a serial number, which
 200                  * reads as a hex number, and tells the device type.
 201                  */
 202                 ret = sr_atoul_base(serno_txt, &serno_num, &end, 16);
 203                 if (ret != SR_OK || !end || *end) {
 204                         sr_warn("Cannot interpret serial number %s.", serno_txt);
 205                         continue;
 206                 }
 207                 dev_type = ASIX_TYPE_NONE;
 208                 dev_text = NULL;
 209                 serno_pre = serno_num >> 16;
 210                 switch (serno_pre) {
 211                 case 0xa601:
 212                         dev_type = ASIX_TYPE_SIGMA;
 213                         dev_text = "SIGMA";
 214                         sr_info("Found SIGMA, serno %s.", serno_txt);
 215                         break;
 216                 case 0xa602:
 217                         dev_type = ASIX_TYPE_SIGMA;
 218                         dev_text = "SIGMA2";
 219                         sr_info("Found SIGMA2, serno %s.", serno_txt);
 220                         break;
 221                 case 0xa603:
 222                         dev_type = ASIX_TYPE_OMEGA;
 223                         dev_text = "OMEGA";
 224                         sr_info("Found OMEGA, serno %s.", serno_txt);
 225                         if (!ASIX_WITH_OMEGA) {
 226                                 sr_warn("OMEGA support is not implemented yet.");
 227                                 continue;
 228                         }
 229                         break;
 230                 default:
 231                         sr_warn("Unknown serno %s, skipping.", serno_txt);
 232                         continue;
 233                 }
 234
 235                 /* Create a device instance, add it to the result set. */
 236
 237                 sdi = g_malloc0(sizeof(*sdi));
 238                 devices = g_slist_append(devices, sdi);
 239                 sdi->status = SR_ST_INITIALIZING;
 240                 sdi->vendor = g_strdup("ASIX");
 241                 sdi->model = g_strdup(dev_text);
 242                 sdi->serial_num = g_strdup(serno_txt);
 243                 sdi->connection_id = g_strdup(conn_id);
 244                 devc = g_malloc0(sizeof(*devc));
 245                 sdi->priv = devc;
 246                 devc->channel_names = sr_parse_probe_names(probe_names,
 247                         channel_names, ARRAY_SIZE(channel_names),
 248                         ARRAY_SIZE(channel_names), &count);
 249                 for (chidx = 0; chidx < count; chidx++)
 250                         sr_channel_new(sdi, chidx, SR_CHANNEL_LOGIC,
 251                                 TRUE, devc->channel_names[chidx]);
 252                 devc->id.vid = des.idVendor;
 253                 devc->id.pid = des.idProduct;
 254                 devc->id.serno = serno_num;
 255                 devc->id.prefix = serno_pre;
 256                 devc->id.type = dev_type;
 257                 sr_sw_limits_init(&devc->limit.config);
 258                 devc->capture_ratio = 50;
 259                 devc->use_triggers = FALSE;
 260
 261                 /* Get current hardware configuration (or use defaults). */
 262                 (void)sigma_fetch_hw_config(sdi);
 263         }
 264         libusb_free_device_list(devlist, 1);
 265         g_slist_free_full(conn_devices, (GDestroyNotify)sr_usb_dev_inst_free);
 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
 274         devc = sdi->priv;
 275
 276         if (devc->id.type == ASIX_TYPE_OMEGA && !ASIX_WITH_OMEGA) {
 277                 sr_err("OMEGA support is not implemented yet.");
 278                 return SR_ERR_NA;
 279         }
 280
 281         return sigma_force_open(sdi);
 282 }
 283
 284 static int dev_close(struct sr_dev_inst *sdi)
 285 {
 286         struct dev_context *devc;
 287
 288         devc = sdi->priv;
 289
 290         return sigma_force_close(devc);
 291 }
 292
 293 static int config_get(uint32_t key, GVariant **data,
 294         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 295 {
 296         struct dev_context *devc;
 297         const char *clock_text;
 298
 299         (void)cg;
 300
 301         if (!sdi)
 302                 return SR_ERR;
 303         devc = sdi->priv;
 304
 305         switch (key) {
 306         case SR_CONF_CONN:
 307                 *data = g_variant_new_string(sdi->connection_id);
 308                 break;
 309         case SR_CONF_SAMPLERATE:
 310                 *data = g_variant_new_uint64(devc->clock.samplerate);
 311                 break;
 312         case SR_CONF_EXTERNAL_CLOCK:
 313                 *data = g_variant_new_boolean(devc->clock.use_ext_clock);
 314                 break;
 315         case SR_CONF_EXTERNAL_CLOCK_SOURCE:
 316                 clock_text = devc->channel_names[devc->clock.clock_pin];
 317                 *data = g_variant_new_string(clock_text);
 318                 break;
 319         case SR_CONF_CLOCK_EDGE:
 320                 clock_text = ext_clock_edges[devc->clock.clock_edge];
 321                 *data = g_variant_new_string(clock_text);
 322                 break;
 323         case SR_CONF_LIMIT_MSEC:
 324         case SR_CONF_LIMIT_SAMPLES:
 325                 return sr_sw_limits_config_get(&devc->limit.config, key, data);
 326         case SR_CONF_CAPTURE_RATIO:
 327                 *data = g_variant_new_uint64(devc->capture_ratio);
 328                 break;
 329         default:
 330                 return SR_ERR_NA;
 331         }
 332
 333         return SR_OK;
 334 }
 335
 336 static int config_set(uint32_t key, GVariant *data,
 337         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 338 {
 339         struct dev_context *devc;
 340         int ret;
 341         uint64_t want_rate, have_rate;
 342         const char **names;
 343         size_t count;
 344         int idx;
 345
 346         (void)cg;
 347
 348         devc = sdi->priv;
 349
 350         switch (key) {
 351         case SR_CONF_SAMPLERATE:
 352                 want_rate = g_variant_get_uint64(data);
 353                 ret = sigma_normalize_samplerate(want_rate, &have_rate);
 354                 if (ret != SR_OK)
 355                         return ret;
 356                 if (have_rate != want_rate) {
 357                         char *text_want, *text_have;
 358                         text_want = sr_samplerate_string(want_rate);
 359                         text_have = sr_samplerate_string(have_rate);
 360                         sr_info("Adjusted samplerate %s to %s.",
 361                                 text_want, text_have);
 362                         g_free(text_want);
 363                         g_free(text_have);
 364                 }
 365                 devc->clock.samplerate = have_rate;
 366                 break;
 367         case SR_CONF_EXTERNAL_CLOCK:
 368                 devc->clock.use_ext_clock = g_variant_get_boolean(data);
 369                 break;
 370         case SR_CONF_EXTERNAL_CLOCK_SOURCE:
 371                 names = (const char **)devc->channel_names;
 372                 count = g_strv_length(devc->channel_names);
 373                 idx = std_str_idx(data, names, count);
 374                 if (idx < 0)
 375                         return SR_ERR_ARG;
 376                 devc->clock.clock_pin = idx;
 377                 break;
 378         case SR_CONF_CLOCK_EDGE:
 379                 idx = std_str_idx(data, ARRAY_AND_SIZE(ext_clock_edges));
 380                 if (idx < 0)
 381                         return SR_ERR_ARG;
 382                 devc->clock.clock_edge = idx;
 383                 break;
 384         case SR_CONF_LIMIT_MSEC:
 385         case SR_CONF_LIMIT_SAMPLES:
 386                 return sr_sw_limits_config_set(&devc->limit.config, key, data);
 387         case SR_CONF_CAPTURE_RATIO:
 388                 devc->capture_ratio = g_variant_get_uint64(data);
 389                 break;
 390         default:
 391                 return SR_ERR_NA;
 392         }
 393
 394         return SR_OK;
 395 }
 396
 397 static int config_list(uint32_t key, GVariant **data,
 398         const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 399 {
 400         struct dev_context *devc;
 401         const char **names;
 402         size_t count;
 403
 404         devc = sdi ? sdi->priv : NULL;
 405         switch (key) {
 406         case SR_CONF_SCAN_OPTIONS:
 407         case SR_CONF_DEVICE_OPTIONS:
 408                 if (cg)
 409                         return SR_ERR_NA;
 410                 return STD_CONFIG_LIST(key, data, sdi, cg,
 411                         scanopts, drvopts, devopts);
 412         case SR_CONF_SAMPLERATE:
 413                 *data = sigma_get_samplerates_list();
 414                 break;
 415         case SR_CONF_EXTERNAL_CLOCK_SOURCE:
 416                 if (!devc)
 417                         return SR_ERR_ARG;
 418                 names = (const char **)devc->channel_names;
 419                 count = g_strv_length(devc->channel_names);
 420                 *data = g_variant_new_strv(names, count);
 421                 break;
 422         case SR_CONF_CLOCK_EDGE:
 423                 *data = g_variant_new_strv(ARRAY_AND_SIZE(ext_clock_edges));
 424                 break;
 425         case SR_CONF_TRIGGER_MATCH:
 426                 *data = std_gvar_array_i32(ARRAY_AND_SIZE(trigger_matches));
 427                 break;
 428         default:
 429                 return SR_ERR_NA;
 430         }
 431
 432         return SR_OK;
 433 }
 434
 435 static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 436 {
 437         struct dev_context *devc;
 438         uint16_t pindis_mask;
 439         uint8_t async, div;
 440         int ret;
 441         size_t triggerpin;
 442         uint8_t trigsel2;
 443         struct triggerinout triggerinout_conf;
 444         struct triggerlut lut;
 445         uint8_t regval, cmd_bytes[4], *wrptr;
 446
 447         devc = sdi->priv;
 448
 449         /* Convert caller's trigger spec to driver's internal format. */
 450         ret = sigma_convert_trigger(sdi);
 451         if (ret != SR_OK) {
 452                 sr_err("Could not configure triggers.");
 453                 return ret;
 454         }
 455
 456         /*
 457          * Setup the device's samplerate from the value which up to now
 458          * just got checked and stored. As a byproduct this can pick and
 459          * send firmware to the device, reduce the number of available
 460          * logic channels, etc.
 461          *
 462          * Determine an acquisition timeout from optionally configured
 463          * sample count or time limits. Which depends on the samplerate.
 464          * Force 50MHz samplerate when external clock is in use.
 465          */
 466         if (devc->clock.use_ext_clock) {
 467                 if (devc->clock.samplerate != SR_MHZ(50))
 468                         sr_info("External clock, forcing 50MHz samplerate.");
 469                 devc->clock.samplerate = SR_MHZ(50);
 470         }
 471         ret = sigma_set_samplerate(sdi);
 472         if (ret != SR_OK)
 473                 return ret;
 474         ret = sigma_set_acquire_timeout(devc);
 475         if (ret != SR_OK)
 476                 return ret;
 477
 478         /* Enter trigger programming mode. */
 479         trigsel2 = TRGSEL2_RESET;
 480         ret = sigma_set_register(devc, WRITE_TRIGGER_SELECT2, trigsel2);
 481         if (ret != SR_OK)
 482                 return ret;
 483
 484         trigsel2 = 0;
 485         if (devc->clock.samplerate >= SR_MHZ(100)) {
 486                 /* 100 and 200 MHz mode. */
 487                 /* TODO Decipher the 0x81 magic number's purpose. */
 488                 ret = sigma_set_register(devc, WRITE_TRIGGER_SELECT2, 0x81);
 489                 if (ret != SR_OK)
 490                         return ret;
 491
 492                 /* Find which pin to trigger on from mask. */
 493                 for (triggerpin = 0; triggerpin < 8; triggerpin++) {
 494                         if (devc->trigger.risingmask & BIT(triggerpin))
 495                                 break;
 496                         if (devc->trigger.fallingmask & BIT(triggerpin))
 497                                 break;
 498                 }
 499
 500                 /* Set trigger pin and light LED on trigger. */
 501                 trigsel2 = triggerpin & TRGSEL2_PINS_MASK;
 502                 trigsel2 |= TRGSEL2_LEDSEL1;
 503
 504                 /* Default rising edge. */
 505                 /* TODO Documentation disagrees, bit set means _rising_ edge. */
 506                 if (devc->trigger.fallingmask)
 507                         trigsel2 |= TRGSEL2_PINPOL_RISE;
 508
 509         } else if (devc->clock.samplerate <= SR_MHZ(50)) {
 510                 /* 50MHz firmware modes. */
 511
 512                 /* Translate application specs to hardware perspective. */
 513                 ret = sigma_build_basic_trigger(devc, &lut);
 514                 if (ret != SR_OK)
 515                         return ret;
 516
 517                 /* Communicate resulting register values to the device. */
 518                 ret = sigma_write_trigger_lut(devc, &lut);
 519                 if (ret != SR_OK)
 520                         return ret;
 521
 522                 trigsel2 = TRGSEL2_LEDSEL1 | TRGSEL2_LEDSEL0;
 523         }
 524
 525         /* Setup trigger in and out pins to default values. */
 526         memset(&triggerinout_conf, 0, sizeof(triggerinout_conf));
 527         triggerinout_conf.trgout_bytrigger = TRUE;
 528         triggerinout_conf.trgout_enable = TRUE;
 529         /* TODO
 530          * Verify the correctness of this implementation. The previous
 531          * version used to assign to a C language struct with bit fields
 532          * which is highly non-portable and hard to guess the resulting
 533          * raw memory layout or wire transfer content. The C struct's
 534          * field names did not match the vendor documentation's names.
 535          * Which means that I could not verify "on paper" either. Let's
 536          * re-visit this code later during research for trigger support.
 537          */
 538         wrptr = cmd_bytes;
 539         regval = 0;
 540         if (triggerinout_conf.trgout_bytrigger)
 541                 regval |= TRGOPT_TRGOOUTEN;
 542         write_u8_inc(&wrptr, regval);
 543         regval &= ~TRGOPT_CLEAR_MASK;
 544         if (triggerinout_conf.trgout_enable)
 545                 regval |= TRGOPT_TRGOEN;
 546         write_u8_inc(&wrptr, regval);
 547         ret = sigma_write_register(devc, WRITE_TRIGGER_OPTION,
 548                 cmd_bytes, wrptr - cmd_bytes);
 549         if (ret != SR_OK)
 550                 return ret;
 551
 552         /* Leave trigger programming mode. */
 553         ret = sigma_set_register(devc, WRITE_TRIGGER_SELECT2, trigsel2);
 554         if (ret != SR_OK)
 555                 return ret;
 556
 557         /*
 558          * Samplerate dependent clock and channels configuration. Some
 559          * channels by design are not available at higher clock rates.
 560          * Register layout differs between firmware variants (depth 1
 561          * with LSB channel mask above 50MHz, depth 4 with more details
 562          * up to 50MHz).
 563          *
 564          * Derive a mask where bits are set for unavailable channels.
 565          * Either send the single byte, or the full byte sequence.
 566          */
 567         pindis_mask = ~BITS_MASK(devc->interp.num_channels);
 568         if (devc->clock.samplerate > SR_MHZ(50)) {
 569                 ret = sigma_set_register(devc, WRITE_CLOCK_SELECT,
 570                         pindis_mask & 0xff);
 571         } else {
 572                 wrptr = cmd_bytes;
 573                 /* Select 50MHz base clock, and divider. */
 574                 async = 0;
 575                 div = SR_MHZ(50) / devc->clock.samplerate - 1;
 576                 if (devc->clock.use_ext_clock) {
 577                         async = CLKSEL_CLKSEL8;
 578                         div = devc->clock.clock_pin + 1;
 579                         switch (devc->clock.clock_edge) {
 580                         case SIGMA_CLOCK_EDGE_RISING:
 581                                 div |= CLKSEL_RISING;
 582                                 break;
 583                         case SIGMA_CLOCK_EDGE_FALLING:
 584                                 div |= CLKSEL_FALLING;
 585                                 break;
 586                         case SIGMA_CLOCK_EDGE_EITHER:
 587                                 div |= CLKSEL_RISING;
 588                                 div |= CLKSEL_FALLING;
 589                                 break;
 590                         }
 591                 }
 592                 write_u8_inc(&wrptr, async);
 593                 write_u8_inc(&wrptr, div);
 594                 write_u16be_inc(&wrptr, pindis_mask);
 595                 ret = sigma_write_register(devc, WRITE_CLOCK_SELECT,
 596                         cmd_bytes, wrptr - cmd_bytes);
 597         }
 598         if (ret != SR_OK)
 599                 return ret;
 600
 601         /* Setup maximum post trigger time. */
 602         ret = sigma_set_register(devc, WRITE_POST_TRIGGER,
 603                 (devc->capture_ratio * 255) / 100);
 604         if (ret != SR_OK)
 605                 return ret;
 606
 607         /* Start acqusition. */
 608         regval = WMR_TRGRES | WMR_SDRAMWRITEEN;
 609         if (devc->use_triggers)
 610                 regval |= WMR_TRGEN;
 611         ret = sigma_set_register(devc, WRITE_MODE, regval);
 612         if (ret != SR_OK)
 613                 return ret;
 614
 615         ret = std_session_send_df_header(sdi);
 616         if (ret != SR_OK)
 617                 return ret;
 618
 619         /* Add capture source. */
 620         ret = sr_session_source_add(sdi->session, -1, 0, 10,
 621                 sigma_receive_data, (void *)sdi);
 622         if (ret != SR_OK)
 623                 return ret;
 624
 625         devc->state = SIGMA_CAPTURE;
 626
 627         return SR_OK;
 628 }
 629
 630 static int dev_acquisition_stop(struct sr_dev_inst *sdi)
 631 {
 632         struct dev_context *devc;
 633
 634         devc = sdi->priv;
 635
 636         /*
 637          * When acquisition is currently running, keep the receive
 638          * routine registered and have it stop the acquisition upon the
 639          * next invocation. Else unregister the receive routine here
 640          * already. The detour is required to have sample data retrieved
 641          * for forced acquisition stops.
 642          */
 643         if (devc->state == SIGMA_CAPTURE) {
 644                 devc->state = SIGMA_STOPPING;
 645         } else {
 646                 devc->state = SIGMA_IDLE;
 647                 (void)sr_session_source_remove(sdi->session, -1);
 648         }
 649
 650         return SR_OK;
 651 }
 652
 653 static struct sr_dev_driver asix_sigma_driver_info = {
 654         .name = "asix-sigma",
 655         .longname = "ASIX SIGMA/SIGMA2",
 656         .api_version = 1,
 657         .init = std_init,
 658         .cleanup = std_cleanup,
 659         .scan = scan,
 660         .dev_list = std_dev_list,
 661         .dev_clear = dev_clear,
 662         .config_get = config_get,
 663         .config_set = config_set,
 664         .config_list = config_list,
 665         .dev_open = dev_open,
 666         .dev_close = dev_close,
 667         .dev_acquisition_start = dev_acquisition_start,
 668         .dev_acquisition_stop = dev_acquisition_stop,
 669         .context = NULL,
 670 };
 671 SR_REGISTER_DEV_DRIVER(asix_sigma_driver_info);