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, see <http://www.gnu.org/licenses/>. *
  18  ***************************************************************************/
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 /* project specific includes */
  25 #include <helper/binarybuffer.h>
  26 #include <jtag/interface.h>
  27 #include <jtag/hla/hla_layout.h>
  28 #include <jtag/hla/hla_transport.h>
  29 #include <jtag/hla/hla_interface.h>
  30 #include <target/target.h>
  31
  32 #include <target/cortex_m.h>
  33
  34 #include <libusb.h>
  35
  36 #define ICDI_WRITE_ENDPOINT 0x02
  37 #define ICDI_READ_ENDPOINT 0x83
  38
  39 #define ICDI_WRITE_TIMEOUT 1000
  40 #define ICDI_READ_TIMEOUT 1000
  41 #define ICDI_PACKET_SIZE 2048
  42
  43 #define PACKET_START "$"
  44 #define PACKET_END "#"
  45
  46 struct icdi_usb_handle_s {
  47         libusb_context *usb_ctx;
  48         libusb_device_handle *usb_dev;
  49
  50         char *read_buffer;
  51         char *write_buffer;
  52         int max_packet;
  53         int read_count;
  54         uint32_t max_rw_packet; /* max X packet (read/write memory) transfers */
  55 };
  56
  57 static int icdi_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
  58                 uint32_t count, uint8_t *buffer);
  59 static int icdi_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
  60                 uint32_t count, const uint8_t *buffer);
  61
  62 static int remote_escape_output(const char *buffer, int len, char *out_buf, int *out_len, int out_maxlen)
  63 {
  64         int input_index, output_index;
  65
  66         output_index = 0;
  67
  68         for (input_index = 0; input_index < len; input_index++) {
  69
  70                 char b = buffer[input_index];
  71
  72                 if (b == '$' || b == '#' || b == '}' || b == '*') {
  73                         /* These must be escaped.  */
  74                         if (output_index + 2 > out_maxlen)
  75                                 break;
  76                         out_buf[output_index++] = '}';
  77                         out_buf[output_index++] = b ^ 0x20;
  78                 } else {
  79                         if (output_index + 1 > out_maxlen)
  80                                 break;
  81                         out_buf[output_index++] = b;
  82                 }
  83         }
  84
  85         *out_len = input_index;
  86         return output_index;
  87 }
  88
  89 static int remote_unescape_input(const char *buffer, int len, char *out_buf, int out_maxlen)
  90 {
  91         int input_index, output_index;
  92         int escaped;
  93
  94         output_index = 0;
  95         escaped = 0;
  96
  97         for (input_index = 0; input_index < len; input_index++) {
  98
  99                 char b = buffer[input_index];
 100
 101                 if (output_index + 1 > out_maxlen)
 102                         LOG_ERROR("Received too much data from the target.");
 103
 104                 if (escaped) {
 105                         out_buf[output_index++] = b ^ 0x20;
 106                         escaped = 0;
 107                 } else if (b == '}')
 108                         escaped = 1;
 109                 else
 110                         out_buf[output_index++] = b;
 111         }
 112
 113         if (escaped)
 114                 LOG_ERROR("Unmatched escape character in target response.");
 115
 116         return output_index;
 117 }
 118
 119 static int icdi_send_packet(void *handle, int len)
 120 {
 121         unsigned char cksum = 0;
 122         struct icdi_usb_handle_s *h = handle;
 123         int result, retry = 0;
 124         int transferred = 0;
 125
 126         assert(handle != NULL);
 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 $...#AA - so we check for # */
 219                         if (h->read_buffer[h->read_count - 3] == '#')
 220                                 return ERROR_OK;
 221                 }
 222
 223                 if (retry++ == 3) {
 224                         LOG_DEBUG("maximum data retries attempted");
 225                         break;
 226                 }
 227         }
 228
 229         return ERROR_FAIL;
 230 }
 231
 232 static int icdi_send_cmd(void *handle, const char *cmd)
 233 {
 234         struct icdi_usb_handle_s *h = handle;
 235
 236         int cmd_len = snprintf(h->write_buffer, h->max_packet, PACKET_START "%s", cmd);
 237         return icdi_send_packet(handle, cmd_len);
 238 }
 239
 240 static int icdi_send_remote_cmd(void *handle, const char *data)
 241 {
 242         struct icdi_usb_handle_s *h = handle;
 243
 244         size_t cmd_len = sprintf(h->write_buffer, PACKET_START "qRcmd,");
 245         cmd_len += hexify(h->write_buffer + cmd_len, data, 0, h->max_packet - cmd_len);
 246
 247         return icdi_send_packet(handle, cmd_len);
 248 }
 249
 250 static int icdi_get_cmd_result(void *handle)
 251 {
 252         struct icdi_usb_handle_s *h = handle;
 253         int offset = 0;
 254         char ch;
 255
 256         assert(handle != NULL);
 257
 258         do {
 259                 ch = h->read_buffer[offset++];
 260                 if (offset > h->read_count)
 261                         return ERROR_FAIL;
 262         } while (ch != '$');
 263
 264         if (memcmp("OK", h->read_buffer + offset, 2) == 0)
 265                 return ERROR_OK;
 266
 267         if (h->read_buffer[offset] == 'E') {
 268                 /* get error code */
 269                 char result;
 270                 if (unhexify(&result, h->read_buffer + offset + 1, 1) != 1)
 271                         return ERROR_FAIL;
 272                 return result;
 273         }
 274
 275         /* for now we assume everything else is ok */
 276         return ERROR_OK;
 277 }
 278
 279 static int icdi_usb_idcode(void *handle, uint32_t *idcode)
 280 {
 281         *idcode = 0;
 282         return ERROR_OK;
 283 }
 284
 285 static int icdi_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val)
 286 {
 287         uint8_t buf[4];
 288         /* REVISIT: There's no target pointer here so there's no way to use target_buffer_set_u32().
 289          * I guess all supported chips are little-endian anyway. */
 290         h_u32_to_le(buf, val);
 291         return icdi_usb_write_mem(handle, addr, 4, 1, buf);
 292 }
 293
 294 static enum target_state icdi_usb_state(void *handle)
 295 {
 296         int result;
 297         struct icdi_usb_handle_s *h = handle;
 298         uint32_t dhcsr;
 299         uint8_t buf[4];
 300
 301         result = icdi_usb_read_mem(h, DCB_DHCSR, 4, 1, buf);
 302         if (result != ERROR_OK)
 303                 return TARGET_UNKNOWN;
 304
 305         /* REVISIT: There's no target pointer here so there's no way to use target_buffer_get_u32().
 306          * I guess all supported chips are little-endian anyway. */
 307         dhcsr = le_to_h_u32(buf);
 308         if (dhcsr & S_HALT)
 309                 return TARGET_HALTED;
 310
 311         return TARGET_RUNNING;
 312 }
 313
 314 static int icdi_usb_version(void *handle)
 315 {
 316         struct icdi_usb_handle_s *h = handle;
 317
 318         char version[20];
 319
 320         /* get info about icdi */
 321         int result = icdi_send_remote_cmd(handle, "version");
 322         if (result != ERROR_OK)
 323                 return result;
 324
 325         if (h->read_count < 8) {
 326                 LOG_ERROR("Invalid Reply Received");
 327                 return ERROR_FAIL;
 328         }
 329
 330         /* convert reply */
 331         if (unhexify(version, h->read_buffer + 2, 4) != 4) {
 332                 LOG_WARNING("unable to get ICDI version");
 333                 return ERROR_OK;
 334         }
 335
 336         /* null terminate and print info */
 337         version[4] = 0;
 338
 339         LOG_INFO("ICDI Firmware version: %s", version);
 340
 341         return ERROR_OK;
 342 }
 343
 344 static int icdi_usb_query(void *handle)
 345 {
 346         int result;
 347
 348         struct icdi_usb_handle_s *h = handle;
 349
 350         result = icdi_send_cmd(handle, "qSupported");
 351         if (result != ERROR_OK)
 352                 return result;
 353
 354         /* check result */
 355         result = icdi_get_cmd_result(handle);
 356         if (result != ERROR_OK) {
 357                 LOG_ERROR("query supported failed: 0x%x", result);
 358                 return ERROR_FAIL;
 359         }
 360
 361         /* from this we can get the max packet supported */
 362
 363         /* query packet buffer size */
 364         char *offset = strstr(h->read_buffer, "PacketSize");
 365         if (offset) {
 366                 char *separator;
 367                 int max_packet;
 368
 369                 max_packet = strtol(offset + 11, &separator, 16);
 370                 if (!max_packet)
 371                         LOG_ERROR("invalid max packet, using defaults");
 372                 else
 373                         h->max_packet = max_packet;
 374                 LOG_DEBUG("max packet supported : %i bytes", h->max_packet);
 375         }
 376
 377
 378         /* if required re allocate packet buffer */
 379         if (h->max_packet != ICDI_PACKET_SIZE) {
 380                 h->read_buffer = realloc(h->read_buffer, h->max_packet);
 381                 h->write_buffer = realloc(h->write_buffer, h->max_packet);
 382                 if (h->read_buffer == 0 || h->write_buffer == 0) {
 383                         LOG_ERROR("unable to reallocate memory");
 384                         return ERROR_FAIL;
 385                 }
 386         }
 387
 388         /* set extended mode */
 389         result = icdi_send_cmd(handle, "!");
 390         if (result != ERROR_OK)
 391                 return result;
 392
 393         /* check result */
 394         result = icdi_get_cmd_result(handle);
 395         if (result != ERROR_OK) {
 396                 LOG_ERROR("unable to enable extended mode: 0x%x", result);
 397                 return ERROR_FAIL;
 398         }
 399
 400         return ERROR_OK;
 401 }
 402
 403 static int icdi_usb_reset(void *handle)
 404 {
 405         /* we do this in hla_target.c */
 406         return ERROR_OK;
 407 }
 408
 409 static int icdi_usb_assert_srst(void *handle, int srst)
 410 {
 411         /* TODO not supported yet */
 412         return ERROR_COMMAND_NOTFOUND;
 413 }
 414
 415 static int icdi_usb_run(void *handle)
 416 {
 417         int result;
 418
 419         /* resume target at current address */
 420         result = icdi_send_cmd(handle, "c");
 421         if (result != ERROR_OK)
 422                 return result;
 423
 424         /* check result */
 425         result = icdi_get_cmd_result(handle);
 426         if (result != ERROR_OK) {
 427                 LOG_ERROR("continue failed: 0x%x", result);
 428                 return ERROR_FAIL;
 429         }
 430
 431         return result;
 432 }
 433
 434 static int icdi_usb_halt(void *handle)
 435 {
 436         int result;
 437
 438         /* this query halts the target ?? */
 439         result = icdi_send_cmd(handle, "?");
 440         if (result != ERROR_OK)
 441                 return result;
 442
 443         /* check result */
 444         result = icdi_get_cmd_result(handle);
 445         if (result != ERROR_OK) {
 446                 LOG_ERROR("halt failed: 0x%x", result);
 447                 return ERROR_FAIL;
 448         }
 449
 450         return result;
 451 }
 452
 453 static int icdi_usb_step(void *handle)
 454 {
 455         int result;
 456
 457         /* step target at current address */
 458         result = icdi_send_cmd(handle, "s");
 459         if (result != ERROR_OK)
 460                 return result;
 461
 462         /* check result */
 463         result = icdi_get_cmd_result(handle);
 464         if (result != ERROR_OK) {
 465                 LOG_ERROR("step failed: 0x%x", result);
 466                 return ERROR_FAIL;
 467         }
 468
 469         return result;
 470 }
 471
 472 static int icdi_usb_read_regs(void *handle)
 473 {
 474         /* currently unsupported */
 475         return ERROR_OK;
 476 }
 477
 478 static int icdi_usb_read_reg(void *handle, int num, uint32_t *val)
 479 {
 480         int result;
 481         struct icdi_usb_handle_s *h = handle;
 482         char cmd[10];
 483
 484         snprintf(cmd, sizeof(cmd), "p%x", num);
 485         result = icdi_send_cmd(handle, cmd);
 486         if (result != ERROR_OK)
 487                 return result;
 488
 489         /* check result */
 490         result = icdi_get_cmd_result(handle);
 491         if (result != ERROR_OK) {
 492                 LOG_ERROR("register read failed: 0x%x", result);
 493                 return ERROR_FAIL;
 494         }
 495
 496         /* convert result */
 497         uint8_t buf[4];
 498         if (unhexify((char *)buf, h->read_buffer + 2, 4) != 4) {
 499                 LOG_ERROR("failed to convert result");
 500                 return ERROR_FAIL;
 501         }
 502         *val = le_to_h_u32(buf);
 503
 504         return result;
 505 }
 506
 507 static int icdi_usb_write_reg(void *handle, int num, uint32_t val)
 508 {
 509         int result;
 510         char cmd[20];
 511         uint8_t buf[4];
 512         h_u32_to_le(buf, val);
 513
 514         int cmd_len = snprintf(cmd, sizeof(cmd), "P%x=", num);
 515         hexify(cmd + cmd_len, (const char *)buf, 4, sizeof(cmd));
 516
 517         result = icdi_send_cmd(handle, cmd);
 518         if (result != ERROR_OK)
 519                 return result;
 520
 521         /* check result */
 522         result = icdi_get_cmd_result(handle);
 523         if (result != ERROR_OK) {
 524                 LOG_ERROR("register write failed: 0x%x", result);
 525                 return ERROR_FAIL;
 526         }
 527
 528         return result;
 529 }
 530
 531 static int icdi_usb_read_mem_int(void *handle, uint32_t addr, uint32_t len, uint8_t *buffer)
 532 {
 533         int result;
 534         struct icdi_usb_handle_s *h = handle;
 535         char cmd[20];
 536
 537         snprintf(cmd, sizeof(cmd), "x%" PRIx32 ",%" PRIx32, addr, len);
 538         result = icdi_send_cmd(handle, cmd);
 539         if (result != ERROR_OK)
 540                 return result;
 541
 542         /* check result */
 543         result = icdi_get_cmd_result(handle);
 544         if (result != ERROR_OK) {
 545                 LOG_ERROR("memory read failed: 0x%x", result);
 546                 return ERROR_FAIL;
 547         }
 548
 549         /* unescape input */
 550         int read_len = remote_unescape_input(h->read_buffer + 5, h->read_count - 8, (char *)buffer, len);
 551         if (read_len != (int)len) {
 552                 LOG_ERROR("read more bytes than expected: actual 0x%x expected 0x%" PRIx32, read_len, len);
 553                 return ERROR_FAIL;
 554         }
 555
 556         return ERROR_OK;
 557 }
 558
 559 static int icdi_usb_write_mem_int(void *handle, uint32_t addr, uint32_t len, const uint8_t *buffer)
 560 {
 561         int result;
 562         struct icdi_usb_handle_s *h = handle;
 563
 564         size_t cmd_len = snprintf(h->write_buffer, h->max_packet, PACKET_START "X%" PRIx32 ",%" PRIx32 ":", addr, len);
 565
 566         int out_len;
 567         cmd_len += remote_escape_output((const char *)buffer, len, h->write_buffer + cmd_len,
 568                         &out_len, h->max_packet - cmd_len);
 569
 570         if (out_len < (int)len) {
 571                 /* for now issue a error as we have no way of allocating a larger buffer */
 572                 LOG_ERROR("memory buffer too small: requires 0x%x actual 0x%" PRIx32, out_len, len);
 573                 return ERROR_FAIL;
 574         }
 575
 576         result = icdi_send_packet(handle, cmd_len);
 577         if (result != ERROR_OK)
 578                 return result;
 579
 580         /* check result */
 581         result = icdi_get_cmd_result(handle);
 582         if (result != ERROR_OK) {
 583                 LOG_ERROR("memory write failed: 0x%x", result);
 584                 return ERROR_FAIL;
 585         }
 586
 587         return ERROR_OK;
 588 }
 589
 590 static int icdi_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
 591                 uint32_t count, uint8_t *buffer)
 592 {
 593         int retval = ERROR_OK;
 594         struct icdi_usb_handle_s *h = handle;
 595         uint32_t bytes_remaining;
 596
 597         /* calculate byte count */
 598         count *= size;
 599
 600         while (count) {
 601
 602                 bytes_remaining = h->max_rw_packet;
 603                 if (count < bytes_remaining)
 604                         bytes_remaining = count;
 605
 606                 retval = icdi_usb_read_mem_int(handle, addr, bytes_remaining, buffer);
 607                 if (retval != ERROR_OK)
 608                         return retval;
 609
 610                 buffer += bytes_remaining;
 611                 addr += bytes_remaining;
 612                 count -= bytes_remaining;
 613         }
 614
 615         return retval;
 616 }
 617
 618 static int icdi_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
 619                 uint32_t count, const uint8_t *buffer)
 620 {
 621         int retval = ERROR_OK;
 622         struct icdi_usb_handle_s *h = handle;
 623         uint32_t bytes_remaining;
 624
 625         /* calculate byte count */
 626         count *= size;
 627
 628         while (count) {
 629
 630                 bytes_remaining = h->max_rw_packet;
 631                 if (count < bytes_remaining)
 632                         bytes_remaining = count;
 633
 634                 retval = icdi_usb_write_mem_int(handle, addr, bytes_remaining, buffer);
 635                 if (retval != ERROR_OK)
 636                         return retval;
 637
 638                 buffer += bytes_remaining;
 639                 addr += bytes_remaining;
 640                 count -= bytes_remaining;
 641         }
 642
 643         return retval;
 644 }
 645
 646 static int icdi_usb_override_target(const char *targetname)
 647 {
 648         return !strcmp(targetname, "cortex_m");
 649 }
 650
 651 static int icdi_usb_close(void *handle)
 652 {
 653         struct icdi_usb_handle_s *h = handle;
 654
 655         if (!h)
 656                 return ERROR_OK;
 657
 658         if (h->usb_dev)
 659                 libusb_close(h->usb_dev);
 660
 661         if (h->usb_ctx)
 662                 libusb_exit(h->usb_ctx);
 663
 664         if (h->read_buffer)
 665                 free(h->read_buffer);
 666
 667         if (h->write_buffer)
 668                 free(h->write_buffer);
 669
 670         free(handle);
 671
 672         return ERROR_OK;
 673 }
 674
 675 static int icdi_usb_open(struct hl_interface_param_s *param, void **fd)
 676 {
 677         int retval;
 678         struct icdi_usb_handle_s *h;
 679
 680         LOG_DEBUG("icdi_usb_open");
 681
 682         h = calloc(1, sizeof(struct icdi_usb_handle_s));
 683
 684         if (h == 0) {
 685                 LOG_ERROR("unable to allocate memory");
 686                 return ERROR_FAIL;
 687         }
 688
 689         LOG_DEBUG("transport: %d vid: 0x%04x pid: 0x%04x", param->transport,
 690                 param->vid, param->pid);
 691
 692         if (libusb_init(&h->usb_ctx) != 0) {
 693                 LOG_ERROR("libusb init failed");
 694                 goto error_open;
 695         }
 696
 697         h->usb_dev = libusb_open_device_with_vid_pid(h->usb_ctx, param->vid, param->pid);
 698         if (!h->usb_dev) {
 699                 LOG_ERROR("open failed");
 700                 goto error_open;
 701         }
 702
 703         if (libusb_claim_interface(h->usb_dev, 2)) {
 704                 LOG_DEBUG("claim interface failed");
 705                 goto error_open;
 706         }
 707
 708         /* check if mode is supported */
 709         retval = ERROR_OK;
 710
 711         switch (param->transport) {
 712 #if 0
 713                 /* TODO place holder as swd is not currently supported */
 714                 case HL_TRANSPORT_SWD:
 715 #endif
 716                 case HL_TRANSPORT_JTAG:
 717                         break;
 718                 default:
 719                         retval = ERROR_FAIL;
 720                         break;
 721         }
 722
 723         if (retval != ERROR_OK) {
 724                 LOG_ERROR("mode (transport) not supported by device");
 725                 goto error_open;
 726         }
 727
 728         /* allocate buffer */
 729         h->read_buffer = malloc(ICDI_PACKET_SIZE);
 730         h->write_buffer = malloc(ICDI_PACKET_SIZE);
 731         h->max_packet = ICDI_PACKET_SIZE;
 732
 733         if (h->read_buffer == 0 || h->write_buffer == 0) {
 734                 LOG_DEBUG("malloc failed");
 735                 goto error_open;
 736         }
 737
 738         /* query icdi version etc */
 739         retval = icdi_usb_version(h);
 740         if (retval != ERROR_OK)
 741                 goto error_open;
 742
 743         /* query icdi support */
 744         retval = icdi_usb_query(h);
 745         if (retval != ERROR_OK)
 746                 goto error_open;
 747
 748         *fd = h;
 749
 750         /* set the max target read/write buffer in bytes
 751          * as we are using gdb binary packets to transfer memory we have to
 752          * reserve half the buffer for any possible escape chars plus
 753          * at least 64 bytes for the gdb packet header */
 754         h->max_rw_packet = (((h->max_packet - 64) / 4) * 4) / 2;
 755
 756         return ERROR_OK;
 757
 758 error_open:
 759         icdi_usb_close(h);
 760
 761         return ERROR_FAIL;
 762 }
 763
 764 struct hl_layout_api_s icdi_usb_layout_api = {
 765         .open = icdi_usb_open,
 766         .close = icdi_usb_close,
 767         .idcode = icdi_usb_idcode,
 768         .state = icdi_usb_state,
 769         .reset = icdi_usb_reset,
 770         .assert_srst = icdi_usb_assert_srst,
 771         .run = icdi_usb_run,
 772         .halt = icdi_usb_halt,
 773         .step = icdi_usb_step,
 774         .read_regs = icdi_usb_read_regs,
 775         .read_reg = icdi_usb_read_reg,
 776         .write_reg = icdi_usb_write_reg,
 777         .read_mem = icdi_usb_read_mem,
 778         .write_mem = icdi_usb_write_mem,
 779         .write_debug_reg = icdi_usb_write_debug_reg,
 780         .override_target = icdi_usb_override_target,
 781         .custom_command = icdi_send_remote_cmd,
 782 };