src/jtag/drivers/ti_icdi_usb.c

   1 /***************************************************************************
   2  *                                                                         *
   3  *   Copyright (C) 2012 by Spencer Oliver                                  *
   4  *   spen@spen-soft.co.uk                                                  *
   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 2 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, write to the                         *
  18  *   Free Software Foundation, Inc.,                                       *
  19  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  20  ***************************************************************************/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 /* project specific includes */
  27 #include <helper/binarybuffer.h>
  28 #include <jtag/interface.h>
  29 #include <jtag/hla/hla_layout.h>
  30 #include <jtag/hla/hla_transport.h>
  31 #include <jtag/hla/hla_interface.h>
  32 #include <target/target.h>
  33
  34 #include <target/cortex_m.h>
  35
  36 #include <libusb-1.0/libusb.h>
  37
  38 #define ICDI_WRITE_ENDPOINT 0x02
  39 #define ICDI_READ_ENDPOINT 0x83
  40
  41 #define ICDI_WRITE_TIMEOUT 1000
  42 #define ICDI_READ_TIMEOUT 1000
  43 #define ICDI_PACKET_SIZE 2048
  44
  45 #define PACKET_START "$"
  46 #define PACKET_END "#"
  47
  48 struct icdi_usb_handle_s {
  49         libusb_context *usb_ctx;
  50         libusb_device_handle *usb_dev;
  51
  52         char *read_buffer;
  53         char *write_buffer;
  54         int max_packet;
  55         int read_count;
  56 };
  57
  58 static int icdi_usb_read_mem32(void *handle, uint32_t addr, uint16_t len, uint8_t *buffer);
  59 static int icdi_usb_write_mem32(void *handle, uint32_t addr, uint16_t len, const uint8_t *buffer);
  60
  61 static int remote_escape_output(const char *buffer, int len, char *out_buf, int *out_len, int out_maxlen)
  62 {
  63         int input_index, output_index;
  64
  65         output_index = 0;
  66
  67         for (input_index = 0; input_index < len; input_index++) {
  68
  69                 char b = buffer[input_index];
  70
  71                 if (b == '$' || b == '#' || b == '}' || b == '*') {
  72                         /* These must be escaped.  */
  73                         if (output_index + 2 > out_maxlen)
  74                                 break;
  75                         out_buf[output_index++] = '}';
  76                         out_buf[output_index++] = b ^ 0x20;
  77                 } else {
  78                         if (output_index + 1 > out_maxlen)
  79                                 break;
  80                         out_buf[output_index++] = b;
  81                 }
  82         }
  83
  84         *out_len = input_index;
  85         return output_index;
  86 }
  87
  88 static int remote_unescape_input(const char *buffer, int len, char *out_buf, int out_maxlen)
  89 {
  90         int input_index, output_index;
  91         int escaped;
  92
  93         output_index = 0;
  94         escaped = 0;
  95
  96         for (input_index = 0; input_index < len; input_index++) {
  97
  98                 char b = buffer[input_index];
  99
 100                 if (output_index + 1 > out_maxlen)
 101                         LOG_ERROR("Received too much data from the target.");
 102
 103                 if (escaped) {
 104                         out_buf[output_index++] = b ^ 0x20;
 105                         escaped = 0;
 106                 } else if (b == '}')
 107                         escaped = 1;
 108                 else
 109                         out_buf[output_index++] = b;
 110         }
 111
 112         if (escaped)
 113                 LOG_ERROR("Unmatched escape character in target response.");
 114
 115         return output_index;
 116 }
 117
 118 static int icdi_send_packet(void *handle, int len)
 119 {
 120         unsigned char cksum = 0;
 121         struct icdi_usb_handle_s *h;
 122         int result, retry = 0;
 123         int transferred = 0;
 124
 125         assert(handle != NULL);
 126         h = (struct icdi_usb_handle_s *)handle;
 127
 128         /* check we have a large enough buffer for checksum "#00" */
 129         if (len + 3 > h->max_packet) {
 130                 LOG_ERROR("packet buffer too small");
 131                 return ERROR_FAIL;
 132         }
 133
 134         /* calculate checksum - offset start of packet */
 135         for (int i = 1; i < len; i++)
 136                 cksum += h->write_buffer[i];
 137
 138         len += sprintf(&h->write_buffer[len], PACKET_END "%02x", cksum);
 139
 140 #ifdef _DEBUG_USB_COMMS_
 141         char buffer[50];
 142         char ch = h->write_buffer[1];
 143         if (ch == 'x' || ch == 'X')
 144                 LOG_DEBUG("writing packet: <binary>");
 145         else {
 146                 memcpy(buffer, h->write_buffer, len >= 50 ? 50-1 : len);
 147                 buffer[len] = 0;
 148                 LOG_DEBUG("writing packet: %s", buffer);
 149         }
 150 #endif
 151
 152         while (1) {
 153
 154                 result = libusb_bulk_transfer(h->usb_dev, ICDI_WRITE_ENDPOINT, (unsigned char *)h->write_buffer, len,
 155                                 &transferred, ICDI_WRITE_TIMEOUT);
 156                 if (result != 0 || transferred != len) {
 157                         LOG_DEBUG("Error TX Data %d", result);
 158                         return ERROR_FAIL;
 159                 }
 160
 161                 /* check that the client got the message ok, or shall we resend */
 162                 result = libusb_bulk_transfer(h->usb_dev, ICDI_READ_ENDPOINT, (unsigned char *)h->read_buffer, h->max_packet,
 163                                         &transferred, ICDI_READ_TIMEOUT);
 164                 if (result != 0 || transferred < 1) {
 165                         LOG_DEBUG("Error RX Data %d", result);
 166                         return ERROR_FAIL;
 167                 }
 168
 169 #ifdef _DEBUG_USB_COMMS_
 170                 LOG_DEBUG("received reply: '%c' : count %d", h->read_buffer[0], transferred);
 171 #endif
 172
 173                 if (h->read_buffer[0] == '-') {
 174                         LOG_DEBUG("Resending packet %d", ++retry);
 175                 } else {
 176                         if (h->read_buffer[0] != '+')
 177                                 LOG_DEBUG("Unexpected Reply from ICDI: %c", h->read_buffer[0]);
 178                         break;
 179                 }
 180
 181                 if (retry == 3) {
 182                         LOG_DEBUG("maximum nack retries attempted");
 183                         return ERROR_FAIL;
 184                 }
 185         }
 186
 187         retry = 0;
 188         h->read_count = transferred;
 189
 190         while (1) {
 191
 192                 /* read reply from icdi */
 193                 result = libusb_bulk_transfer(h->usb_dev, ICDI_READ_ENDPOINT, (unsigned char *)h->read_buffer + h->read_count,
 194                                 h->max_packet - h->read_count, &transferred, ICDI_READ_TIMEOUT);
 195
 196 #ifdef _DEBUG_USB_COMMS_
 197                 LOG_DEBUG("received data: count %d", transferred);
 198 #endif
 199
 200                 /* check for errors but retry for timeout */
 201                 if (result != 0) {
 202
 203                         if (result == LIBUSB_ERROR_TIMEOUT) {
 204                                 LOG_DEBUG("Error RX timeout %d", result);
 205                         } else {
 206                                 LOG_DEBUG("Error RX Data %d", result);
 207                                 return ERROR_FAIL;
 208                         }
 209                 }
 210
 211                 h->read_count += transferred;
 212
 213                 /* we need to make sure we have a full packet, including checksum */
 214                 if (h->read_count > 5) {
 215
 216                         /* check that we have received an packet delimiter
 217                          * we do not validate the checksum
 218                          * reply should contain $...#AA - so we check for # */
 219                         if (h->read_buffer[h->read_count - 3] == '#')
 220                                 return ERROR_OK;
 221                 }
 222
 223                 if (retry++ == 3) {
 224                         LOG_DEBUG("maximum data retries attempted");
 225                         break;
 226                 }
 227         }
 228
 229         return ERROR_FAIL;
 230 }
 231
 232 static int icdi_send_cmd(void *handle, const char *cmd)
 233 {
 234         struct icdi_usb_handle_s *h;
 235         h = (struct icdi_usb_handle_s *)handle;
 236
 237         int cmd_len = snprintf(h->write_buffer, h->max_packet, PACKET_START "%s", cmd);
 238         return icdi_send_packet(handle, cmd_len);
 239 }
 240
 241 static int icdi_send_remote_cmd(void *handle, const char *data)
 242 {
 243         struct icdi_usb_handle_s *h;
 244         h = (struct icdi_usb_handle_s *)handle;
 245
 246         size_t cmd_len = sprintf(h->write_buffer, PACKET_START "qRcmd,");
 247         cmd_len += hexify(h->write_buffer + cmd_len, data, 0, h->max_packet - cmd_len);
 248
 249         return icdi_send_packet(handle, cmd_len);
 250 }
 251
 252 static int icdi_get_cmd_result(void *handle)
 253 {
 254         struct icdi_usb_handle_s *h;
 255         int offset = 0;
 256         char ch;
 257
 258         assert(handle != NULL);
 259         h = (struct icdi_usb_handle_s *)handle;
 260
 261         do {
 262                 ch = h->read_buffer[offset++];
 263                 if (offset > h->read_count)
 264                         return ERROR_FAIL;
 265         } while (ch != '$');
 266
 267         if (memcmp("OK", h->read_buffer + offset, 2) == 0)
 268                 return ERROR_OK;
 269
 270         if (h->read_buffer[offset] == 'E') {
 271                 /* get error code */
 272                 char result;
 273                 if (unhexify(&result, h->read_buffer + offset + 1, 1) != 1)
 274                         return ERROR_FAIL;
 275                 return result;
 276         }
 277
 278         /* for now we assume everything else is ok */
 279         return ERROR_OK;
 280 }
 281
 282 static int icdi_usb_idcode(void *handle, uint32_t *idcode)
 283 {
 284         return ERROR_OK;
 285 }
 286
 287 static int icdi_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val)
 288 {
 289         return icdi_usb_write_mem32(handle, addr, 1, (uint8_t *)&val);
 290 }
 291
 292 static enum target_state icdi_usb_state(void *handle)
 293 {
 294         int result;
 295         struct icdi_usb_handle_s *h;
 296         uint32_t dhcsr;
 297
 298         h = (struct icdi_usb_handle_s *)handle;
 299
 300         result = icdi_usb_read_mem32(h, DCB_DHCSR, 1, (uint8_t *)&dhcsr);
 301         if (result != ERROR_OK)
 302                 return TARGET_UNKNOWN;
 303
 304         if (dhcsr & S_HALT)
 305                 return TARGET_HALTED;
 306
 307         return TARGET_RUNNING;
 308 }
 309
 310 static int icdi_usb_version(void *handle)
 311 {
 312         struct icdi_usb_handle_s *h;
 313         h = (struct icdi_usb_handle_s *)handle;
 314
 315         char version[20];
 316
 317         /* get info about icdi */
 318         int result = icdi_send_remote_cmd(handle, "version");
 319         if (result != ERROR_OK)
 320                 return result;
 321
 322         if (h->read_count < 8) {
 323                 LOG_ERROR("Invalid Reply Received");
 324                 return ERROR_FAIL;
 325         }
 326
 327         /* convert reply */
 328         if (unhexify(version, h->read_buffer + 2, 4) != 4) {
 329                 LOG_WARNING("unable to get ICDI version");
 330                 return ERROR_OK;
 331         }
 332
 333         /* null terminate and print info */
 334         version[4] = 0;
 335
 336         LOG_INFO("ICDI Firmware version: %s", version);
 337
 338         return ERROR_OK;
 339 }
 340
 341 static int icdi_usb_query(void *handle)
 342 {
 343         int result;
 344
 345         struct icdi_usb_handle_s *h;
 346         h = (struct icdi_usb_handle_s *)handle;
 347
 348         result = icdi_send_cmd(handle, "qSupported");
 349         if (result != ERROR_OK)
 350                 return result;
 351
 352         /* check result */
 353         result = icdi_get_cmd_result(handle);
 354         if (result != ERROR_OK) {
 355                 LOG_ERROR("query supported failed: 0x%x", result);
 356                 return ERROR_FAIL;
 357         }
 358
 359         /* from this we can get the max packet supported */
 360
 361         /* query packet buffer size */
 362         char *offset = strstr(h->read_buffer, "PacketSize");
 363         if (offset) {
 364                 char *separator;
 365                 int max_packet;
 366
 367                 max_packet = strtoul(offset + 11, &separator, 16);
 368                 if (!max_packet)
 369                         LOG_ERROR("invalid max packet, using defaults");
 370                 else
 371                         h->max_packet = max_packet;
 372                 LOG_DEBUG("max packet supported : %" PRIu32 " bytes", h->max_packet);
 373         }
 374
 375
 376         /* if required re allocate packet buffer */
 377         if (h->max_packet != ICDI_PACKET_SIZE) {
 378                 h->read_buffer = realloc(h->read_buffer, h->max_packet);
 379                 h->write_buffer = realloc(h->write_buffer, h->max_packet);
 380                 if (h->read_buffer == 0 || h->write_buffer == 0) {
 381                         LOG_ERROR("unable to reallocate memory");
 382                         return ERROR_FAIL;
 383                 }
 384         }
 385
 386         /* set extended mode */
 387         result = icdi_send_cmd(handle, "!");
 388
 389         /* check result */
 390         result = icdi_get_cmd_result(handle);
 391         if (result != ERROR_OK) {
 392                 LOG_ERROR("unable to enable extended mode: 0x%x", result);
 393                 return ERROR_FAIL;
 394         }
 395
 396         return ERROR_OK;
 397 }
 398
 399 static int icdi_usb_reset(void *handle)
 400 {
 401         /* we do this in hla_target.c */
 402         return ERROR_OK;
 403 }
 404
 405 static int icdi_usb_assert_srst(void *handle, int srst)
 406 {
 407         /* TODO not supported yet */
 408         return ERROR_COMMAND_NOTFOUND;
 409 }
 410
 411 static int icdi_usb_run(void *handle)
 412 {
 413         int result;
 414
 415         /* resume target at current address */
 416         result = icdi_send_cmd(handle, "c");
 417         if (result != ERROR_OK)
 418                 return result;
 419
 420         /* check result */
 421         result = icdi_get_cmd_result(handle);
 422         if (result != ERROR_OK) {
 423                 LOG_ERROR("continue failed: 0x%x", result);
 424                 return ERROR_FAIL;
 425         }
 426
 427         return result;
 428 }
 429
 430 static int icdi_usb_halt(void *handle)
 431 {
 432         int result;
 433
 434         /* this query halts the target ?? */
 435         result = icdi_send_cmd(handle, "?");
 436         if (result != ERROR_OK)
 437                 return result;
 438
 439         /* check result */
 440         result = icdi_get_cmd_result(handle);
 441         if (result != ERROR_OK) {
 442                 LOG_ERROR("halt failed: 0x%x", result);
 443                 return ERROR_FAIL;
 444         }
 445
 446         return result;
 447 }
 448
 449 static int icdi_usb_step(void *handle)
 450 {
 451         int result;
 452
 453         /* step target at current address */
 454         result = icdi_send_cmd(handle, "s");
 455         if (result != ERROR_OK)
 456                 return result;
 457
 458         /* check result */
 459         result = icdi_get_cmd_result(handle);
 460         if (result != ERROR_OK) {
 461                 LOG_ERROR("step failed: 0x%x", result);
 462                 return ERROR_FAIL;
 463         }
 464
 465         return result;
 466 }
 467
 468 static int icdi_usb_read_regs(void *handle)
 469 {
 470         /* currently unsupported */
 471         return ERROR_OK;
 472 }
 473
 474 static int icdi_usb_read_reg(void *handle, int num, uint32_t *val)
 475 {
 476         int result;
 477         struct icdi_usb_handle_s *h;
 478         char cmd[10];
 479
 480         h = (struct icdi_usb_handle_s *)handle;
 481
 482         snprintf(cmd, sizeof(cmd), "p%x", num);
 483         result = icdi_send_cmd(handle, cmd);
 484         if (result != ERROR_OK)
 485                 return result;
 486
 487         /* check result */
 488         result = icdi_get_cmd_result(handle);
 489         if (result != ERROR_OK) {
 490                 LOG_ERROR("register read failed: 0x%x", result);
 491                 return ERROR_FAIL;
 492         }
 493
 494         /* convert result */
 495         if (unhexify((char *)val, h->read_buffer + 2, 4) != 4) {
 496                 LOG_ERROR("failed to convert result");
 497                 return ERROR_FAIL;
 498         }
 499
 500         return result;
 501 }
 502
 503 static int icdi_usb_write_reg(void *handle, int num, uint32_t val)
 504 {
 505         int result;
 506         char cmd[20];
 507
 508         int cmd_len = snprintf(cmd, sizeof(cmd), "P%x=", num);
 509         hexify(cmd + cmd_len, (char *)&val, 4, sizeof(cmd));
 510
 511         result = icdi_send_cmd(handle, cmd);
 512         if (result != ERROR_OK)
 513                 return result;
 514
 515         /* check result */
 516         result = icdi_get_cmd_result(handle);
 517         if (result != ERROR_OK) {
 518                 LOG_ERROR("register write failed: 0x%x", result);
 519                 return ERROR_FAIL;
 520         }
 521
 522         return result;
 523 }
 524
 525 static int icdi_usb_read_mem(void *handle, uint32_t addr, uint32_t len, uint8_t *buffer)
 526 {
 527         int result;
 528         struct icdi_usb_handle_s *h;
 529         char cmd[20];
 530
 531         h = (struct icdi_usb_handle_s *)handle;
 532
 533         snprintf(cmd, sizeof(cmd), "x%x,%x", addr, len);
 534         result = icdi_send_cmd(handle, cmd);
 535         if (result != ERROR_OK)
 536                 return result;
 537
 538         /* check result */
 539         result = icdi_get_cmd_result(handle);
 540         if (result != ERROR_OK) {
 541                 LOG_ERROR("memory read failed: 0x%x", result);
 542                 return ERROR_FAIL;
 543         }
 544
 545         /* unescape input */
 546         int read_len = remote_unescape_input(h->read_buffer + 5, h->read_count - 8, (char *)buffer, len);
 547         if (read_len != (int)len) {
 548                 LOG_ERROR("read more bytes than expected: actual 0x%" PRIx32 " expected 0x%" PRIx32, read_len, len);
 549                 return ERROR_FAIL;
 550         }
 551
 552         return ERROR_OK;
 553 }
 554
 555 static int icdi_usb_write_mem(void *handle, uint32_t addr, uint32_t len, const uint8_t *buffer)
 556 {
 557         int result;
 558         struct icdi_usb_handle_s *h;
 559
 560         h = (struct icdi_usb_handle_s *)handle;
 561
 562         size_t cmd_len = snprintf(h->write_buffer, h->max_packet, PACKET_START "X%x,%x:", addr, len);
 563
 564         int out_len;
 565         cmd_len += remote_escape_output((char *)buffer, len, h->write_buffer + cmd_len,
 566                         &out_len, h->max_packet - cmd_len);
 567
 568         if (out_len < (int)len) {
 569                 /* for now issue a error as we have no way of allocating a larger buffer */
 570                 LOG_ERROR("memory buffer too small: requires 0x%" PRIx32 " actual 0x%" PRIx32, out_len, len);
 571                 return ERROR_FAIL;
 572         }
 573
 574         result = icdi_send_packet(handle, cmd_len);
 575         if (result != ERROR_OK)
 576                 return result;
 577
 578         /* check result */
 579         result = icdi_get_cmd_result(handle);
 580         if (result != ERROR_OK) {
 581                 LOG_ERROR("memory write failed: 0x%x", result);
 582                 return ERROR_FAIL;
 583         }
 584
 585         return ERROR_OK;
 586 }
 587
 588 static int icdi_usb_read_mem8(void *handle, uint32_t addr, uint16_t len, uint8_t *buffer)
 589 {
 590         return icdi_usb_read_mem(handle, addr, len, buffer);
 591 }
 592
 593 static int icdi_usb_write_mem8(void *handle, uint32_t addr, uint16_t len, const uint8_t *buffer)
 594 {
 595         return icdi_usb_write_mem(handle, addr, len, buffer);
 596 }
 597
 598 static int icdi_usb_read_mem32(void *handle, uint32_t addr, uint16_t len, uint8_t *buffer)
 599 {
 600         return icdi_usb_read_mem(handle, addr, len * 4, buffer);
 601 }
 602
 603 static int icdi_usb_write_mem32(void *handle, uint32_t addr, uint16_t len, const uint8_t *buffer)
 604 {
 605         return icdi_usb_write_mem(handle, addr, len * 4, buffer);
 606 }
 607
 608 static int icdi_usb_close(void *handle)
 609 {
 610         struct icdi_usb_handle_s *h;
 611
 612         h = (struct icdi_usb_handle_s *)handle;
 613
 614         if (h->usb_dev)
 615                 libusb_close(h->usb_dev);
 616
 617         if (h->usb_ctx)
 618                 libusb_exit(h->usb_ctx);
 619
 620         if (h->read_buffer)
 621                 free(h->read_buffer);
 622
 623         if (h->write_buffer)
 624                 free(h->write_buffer);
 625
 626         free(handle);
 627
 628         return ERROR_OK;
 629 }
 630
 631 static int icdi_usb_open(struct hl_interface_param_s *param, void **fd)
 632 {
 633         int retval;
 634         struct icdi_usb_handle_s *h;
 635
 636         LOG_DEBUG("icdi_usb_open");
 637
 638         h = calloc(1, sizeof(struct icdi_usb_handle_s));
 639
 640         if (h == 0) {
 641                 LOG_ERROR("unable to allocate memory");
 642                 return ERROR_FAIL;
 643         }
 644
 645         LOG_DEBUG("transport: %d vid: 0x%04x pid: 0x%04x", param->transport,
 646                 param->vid, param->pid);
 647
 648         if (libusb_init(&h->usb_ctx) != 0) {
 649                 LOG_ERROR("libusb init failed");
 650                 goto error_open;
 651         }
 652
 653         h->usb_dev = libusb_open_device_with_vid_pid(h->usb_ctx, param->vid, param->pid);
 654         if (!h->usb_dev) {
 655                 LOG_ERROR("open failed");
 656                 goto error_open;
 657         }
 658
 659         if (libusb_claim_interface(h->usb_dev, 2)) {
 660                 LOG_DEBUG("claim interface failed");
 661                 goto error_open;
 662         }
 663
 664         /* check if mode is supported */
 665         retval = ERROR_OK;
 666
 667         switch (param->transport) {
 668 #if 0
 669                 /* TODO place holder as swd is not currently supported */
 670                 case HL_TRANSPORT_SWD:
 671 #endif
 672                 case HL_TRANSPORT_JTAG:
 673                         break;
 674                 default:
 675                         retval = ERROR_FAIL;
 676                         break;
 677         }
 678
 679         if (retval != ERROR_OK) {
 680                 LOG_ERROR("mode (transport) not supported by device");
 681                 goto error_open;
 682         }
 683
 684         /* allocate buffer */
 685         h->read_buffer = malloc(ICDI_PACKET_SIZE);
 686         h->write_buffer = malloc(ICDI_PACKET_SIZE);
 687         h->max_packet = ICDI_PACKET_SIZE;
 688
 689         if (h->read_buffer == 0 || h->write_buffer == 0) {
 690                 LOG_DEBUG("malloc failed");
 691                 goto error_open;
 692         }
 693
 694         /* query icdi version etc */
 695         retval = icdi_usb_version(h);
 696         if (retval != ERROR_OK)
 697                 goto error_open;
 698
 699         /* query icdi support */
 700         retval = icdi_usb_query(h);
 701         if (retval != ERROR_OK)
 702                 goto error_open;
 703
 704         *fd = h;
 705
 706         /* set the max target read/write buffer in bytes
 707          * as we are using gdb binary packets to transfer memory we have to
 708          * reserve half the buffer for any possible escape chars plus
 709          * at least 64 bytes for the gdb packet header */
 710         param->max_buffer = (((h->max_packet - 64) / 4) * 4) / 2;
 711
 712         return ERROR_OK;
 713
 714 error_open:
 715         icdi_usb_close(h);
 716
 717         return ERROR_FAIL;
 718 }
 719
 720 struct hl_layout_api_s icdi_usb_layout_api = {
 721         .open = icdi_usb_open,
 722         .close = icdi_usb_close,
 723         .idcode = icdi_usb_idcode,
 724         .state = icdi_usb_state,
 725         .reset = icdi_usb_reset,
 726         .assert_srst = icdi_usb_assert_srst,
 727         .run = icdi_usb_run,
 728         .halt = icdi_usb_halt,
 729         .step = icdi_usb_step,
 730         .read_regs = icdi_usb_read_regs,
 731         .read_reg = icdi_usb_read_reg,
 732         .write_reg = icdi_usb_write_reg,
 733         .read_mem8 = icdi_usb_read_mem8,
 734         .write_mem8 = icdi_usb_write_mem8,
 735         .read_mem32 = icdi_usb_read_mem32,
 736         .write_mem32 = icdi_usb_write_mem32,
 737         .write_debug_reg = icdi_usb_write_debug_reg
 738 };