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   1 /***************************************************************************
   2  *   Copyright (C) 2009 by Dimitar Dimitrov <dinuxbg@gmail.com>            *
   3  *   based on Dominic Rath's and Benedikt Sauter's usbprog.c               *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24
  25 #include "interface.h"
  26 #include <jtag/commands.h>
  27 #include <usb.h>
  28 #include "usb_common.h"
  29
  30
  31 #define USB_VID                                         0x15ba
  32 #define USB_PID                                         0x001e
  33
  34 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  35 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  36
  37 #define ARMJTAGEW_USB_TIMEOUT           2000
  38
  39 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  40 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  41
  42
  43 /* USB command request codes. */
  44 #define CMD_GET_VERSION                         0x00
  45 #define CMD_SELECT_DPIMPL                       0x10
  46 #define CMD_SET_TCK_FREQUENCY           0x11
  47 #define CMD_GET_TCK_FREQUENCY           0x12
  48 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  49 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  50 #define CMD_TAP_SHIFT                           0x17
  51 #define CMD_SET_TAPHW_STATE                     0x20
  52 #define CMD_GET_TAPHW_STATE                     0x21
  53 #define CMD_TGPWR_SETUP                         0x22
  54
  55 /* Global USB buffers */
  56 static uint8_t usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  57 static uint8_t usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  58
  59 /* Queue command functions */
  60 static void armjtagew_end_state(tap_state_t state);
  61 static void armjtagew_state_move(void);
  62 static void armjtagew_path_move(int num_states, tap_state_t *path);
  63 static void armjtagew_runtest(int num_cycles);
  64 static void armjtagew_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, struct scan_command *command);
  65 static void armjtagew_reset(int trst, int srst);
  66 //static void armjtagew_simple_command(uint8_t command);
  67 static int armjtagew_get_status(void);
  68
  69 /* tap buffer functions */
  70 static void armjtagew_tap_init(void);
  71 static int armjtagew_tap_execute(void);
  72 static void armjtagew_tap_ensure_space(int scans, int bits);
  73 static void armjtagew_tap_append_step(int tms, int tdi);
  74 static void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command);
  75
  76 /* ARM-JTAG-EW lowlevel functions */
  77 struct armjtagew {
  78         struct usb_dev_handle* usb_handle;
  79 };
  80
  81 static struct armjtagew *armjtagew_usb_open(void);
  82 static void armjtagew_usb_close(struct armjtagew *armjtagew);
  83 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length);
  84 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length);
  85 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length);
  86
  87 /* helper functions */
  88 static int armjtagew_get_version_info(void);
  89
  90 #ifdef _DEBUG_USB_COMMS_
  91 static void armjtagew_debug_buffer(uint8_t *buffer, int length);
  92 #endif
  93
  94 static struct armjtagew* armjtagew_handle;
  95
  96
  97
  98 /***************************************************************************/
  99 /* External interface implementation */
 100
 101 static int armjtagew_execute_queue(void)
 102 {
 103         struct jtag_command *cmd = jtag_command_queue;
 104         int scan_size;
 105         enum scan_type type;
 106         uint8_t *buffer;
 107
 108         while (cmd != NULL)
 109         {
 110                 switch (cmd->type)
 111                 {
 112                         case JTAG_RUNTEST:
 113                                 DEBUG_JTAG_IO("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, \
 114                                         cmd->cmd.runtest->end_state);
 115
 116                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 117                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 118                                 break;
 119
 120                         case JTAG_STATEMOVE:
 121                                 DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 122
 123                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 124                                 armjtagew_state_move();
 125                                 break;
 126
 127                         case JTAG_PATHMOVE:
 128                                 DEBUG_JTAG_IO("pathmove: %i states, end in %i", \
 129                                         cmd->cmd.pathmove->num_states, \
 130                                         cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 131
 132                                 armjtagew_path_move(cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path);
 133                                 break;
 134
 135                         case JTAG_SCAN:
 136                                 DEBUG_JTAG_IO("scan end in %i", cmd->cmd.scan->end_state);
 137
 138                                 armjtagew_end_state(cmd->cmd.scan->end_state);
 139
 140                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 141                                 DEBUG_JTAG_IO("scan input, length = %d", scan_size);
 142
 143 #ifdef _DEBUG_USB_COMMS_
 144                                 armjtagew_debug_buffer(buffer, (scan_size + 7) / 8);
 145 #endif
 146                                 type = jtag_scan_type(cmd->cmd.scan);
 147                                 armjtagew_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size, cmd->cmd.scan);
 148                                 break;
 149
 150                         case JTAG_RESET:
 151                                 DEBUG_JTAG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 152
 153                                 armjtagew_tap_execute();
 154
 155                                 if (cmd->cmd.reset->trst == 1)
 156                                 {
 157                                         tap_set_state(TAP_RESET);
 158                                 }
 159                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 160                                 break;
 161
 162                         case JTAG_SLEEP:
 163                                 DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 164                                 armjtagew_tap_execute();
 165                                 jtag_sleep(cmd->cmd.sleep->us);
 166                                 break;
 167
 168                         default:
 169                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 170                                 exit(-1);
 171                 }
 172                 cmd = cmd->next;
 173         }
 174
 175         return armjtagew_tap_execute();
 176 }
 177
 178
 179 /* Sets speed in kHz. */
 180 static int armjtagew_speed(int speed)
 181 {
 182     int result;
 183     int speed_real;
 184
 185
 186     usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 187         buf_set_u32(usb_out_buffer + 1, 0, 32, speed);
 188
 189     result = armjtagew_usb_message(armjtagew_handle, 4, 4);
 190
 191     if (result < 0)
 192     {
 193         LOG_ERROR("ARM-JTAG-EW setting speed failed (%d)", result);
 194         return ERROR_JTAG_DEVICE_ERROR;
 195     }
 196
 197         usb_out_buffer[0] = CMD_GET_TCK_FREQUENCY;
 198     result = armjtagew_usb_message(armjtagew_handle, 1, 4);
 199         speed_real = (int)buf_get_u32(usb_in_buffer,0,32);
 200         if (result < 0)
 201         {
 202         LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 203         return ERROR_JTAG_DEVICE_ERROR;
 204         }
 205         else
 206         {
 207         LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 208         }
 209
 210     return ERROR_OK;
 211 }
 212
 213
 214 static int armjtagew_khz(int khz, int *jtag_speed)
 215 {
 216         *jtag_speed = khz;
 217
 218         return ERROR_OK;
 219 }
 220
 221 static int armjtagew_init(void)
 222 {
 223         int check_cnt;
 224
 225         armjtagew_handle = armjtagew_usb_open();
 226
 227         if (armjtagew_handle == 0)
 228         {
 229                 LOG_ERROR("Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 230                 return ERROR_JTAG_INIT_FAILED;
 231         }
 232
 233         check_cnt = 0;
 234         while (check_cnt < 3)
 235         {
 236                 if (armjtagew_get_version_info() == ERROR_OK)
 237                 {
 238                         /* attempt to get status */
 239                         armjtagew_get_status();
 240                         break;
 241                 }
 242
 243                 check_cnt++;
 244         }
 245
 246         if (check_cnt == 3)
 247         {
 248                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 249         }
 250
 251         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 252
 253         armjtagew_reset(0, 0);
 254         armjtagew_tap_init();
 255
 256         return ERROR_OK;
 257 }
 258
 259 static int armjtagew_quit(void)
 260 {
 261         armjtagew_usb_close(armjtagew_handle);
 262         return ERROR_OK;
 263 }
 264
 265 /***************************************************************************/
 266 /* Queue command implementations */
 267
 268 static void armjtagew_end_state(tap_state_t state)
 269 {
 270         if (tap_is_state_stable(state))
 271         {
 272                 tap_set_end_state(state);
 273         }
 274         else
 275         {
 276                 LOG_ERROR("BUG: %i is not a valid end state", state);
 277                 exit(-1);
 278         }
 279 }
 280
 281 /* Goes to the end state. */
 282 static void armjtagew_state_move(void)
 283 {
 284         int i;
 285         int tms = 0;
 286         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 287         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 288
 289         for (i = 0; i < tms_count; i++)
 290         {
 291                 tms = (tms_scan >> i) & 1;
 292                 armjtagew_tap_append_step(tms, 0);
 293         }
 294
 295         tap_set_state(tap_get_end_state());
 296 }
 297
 298 static void armjtagew_path_move(int num_states, tap_state_t *path)
 299 {
 300         int i;
 301
 302         for (i = 0; i < num_states; i++)
 303         {
 304                 /*
 305                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 306                  * Either handle that here, or update the documentation with examples
 307                  * how to fix that in the configuration files.
 308                  */
 309                 if (path[i] == tap_state_transition(tap_get_state(), false))
 310                 {
 311                         armjtagew_tap_append_step(0, 0);
 312                 }
 313                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 314                 {
 315                         armjtagew_tap_append_step(1, 0);
 316                 }
 317                 else
 318                 {
 319                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 320                         exit(-1);
 321                 }
 322
 323                 tap_set_state(path[i]);
 324         }
 325
 326         tap_set_end_state(tap_get_state());
 327 }
 328
 329 static void armjtagew_runtest(int num_cycles)
 330 {
 331         int i;
 332
 333         tap_state_t saved_end_state = tap_get_end_state();
 334
 335         /* only do a state_move when we're not already in IDLE */
 336         if (tap_get_state() != TAP_IDLE)
 337         {
 338                 armjtagew_end_state(TAP_IDLE);
 339                 armjtagew_state_move();
 340         }
 341
 342         /* execute num_cycles */
 343         for (i = 0; i < num_cycles; i++)
 344         {
 345                 armjtagew_tap_append_step(0, 0);
 346         }
 347
 348         /* finish in end_state */
 349         armjtagew_end_state(saved_end_state);
 350         if (tap_get_state() != tap_get_end_state())
 351         {
 352                 armjtagew_state_move();
 353         }
 354 }
 355
 356 static void armjtagew_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, struct scan_command *command)
 357 {
 358         tap_state_t saved_end_state;
 359
 360         armjtagew_tap_ensure_space(1, scan_size + 8);
 361
 362         saved_end_state = tap_get_end_state();
 363
 364         /* Move to appropriate scan state */
 365         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 366
 367         armjtagew_state_move();
 368         armjtagew_end_state(saved_end_state);
 369
 370         /* Scan */
 371         armjtagew_tap_append_scan(scan_size, buffer, command);
 372
 373         /* We are in Exit1, go to Pause */
 374         armjtagew_tap_append_step(0, 0);
 375
 376         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 377
 378         if (tap_get_state() != tap_get_end_state())
 379         {
 380                 armjtagew_state_move();
 381         }
 382 }
 383
 384 static void armjtagew_reset(int trst, int srst)
 385 {
 386         const uint8_t trst_mask = (1u << 5);
 387         const uint8_t srst_mask = (1u << 6);
 388         uint8_t val = 0;
 389         uint8_t outp_en = 0;
 390         uint8_t change_mask = 0;
 391         int result;
 392
 393         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 394
 395         if (srst == 0)
 396         {
 397                 val |= srst_mask;
 398                 outp_en &= ~srst_mask;          /* tristate */
 399                 change_mask |= srst_mask;
 400         }
 401         else if (srst == 1)
 402         {
 403                 val &= ~srst_mask;
 404                 outp_en |= srst_mask;
 405                 change_mask |= srst_mask;
 406         }
 407
 408         if (trst == 0)
 409         {
 410                 val |= trst_mask;
 411                 outp_en &= ~trst_mask;          /* tristate */
 412                 change_mask |= trst_mask;
 413         }
 414         else if (trst == 1)
 415         {
 416                 val &= ~trst_mask;
 417                 outp_en |= trst_mask;
 418                 change_mask |= trst_mask;
 419         }
 420
 421         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 422         usb_out_buffer[1] = val;
 423         usb_out_buffer[2] = outp_en;
 424         usb_out_buffer[3] = change_mask;
 425         result = armjtagew_usb_write(armjtagew_handle, 4);
 426         if (result != 4)
 427         {
 428                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 429         }
 430 }
 431
 432
 433 static int armjtagew_get_status(void)
 434 {
 435         int result;
 436
 437         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 438         result = armjtagew_usb_message(armjtagew_handle, 1, 12);
 439
 440         if (result == 0)
 441         {
 442                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 443                 LOG_INFO("U_tg = %d mV, U_aux = %d mV, U_tgpwr = %d mV, I_tgpwr = %d mA, D1 = %d, Target power %s %s\n",
 444                          (int)(buf_get_u32(usb_in_buffer + 0, 0, 16)),
 445                          (int)(buf_get_u32(usb_in_buffer + 2, 0, 16)),
 446                          (int)(buf_get_u32(usb_in_buffer + 4, 0, 16)),
 447                          (int)(buf_get_u32(usb_in_buffer + 6, 0, 16)),
 448                          usb_in_buffer[9],
 449                          usb_in_buffer[11] ? "OVERCURRENT" : "OK",
 450                          usb_in_buffer[10] ? "enabled" : "disabled");
 451
 452                 if (u_tg < 1500)
 453                 {
 454                         LOG_ERROR("Vref too low. Check Target Power\n");
 455                 }
 456         }
 457         else
 458         {
 459                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)\n", result);
 460         }
 461
 462         return ERROR_OK;
 463 }
 464
 465 static int armjtagew_get_version_info(void)
 466 {
 467         int result;
 468         char sn[16];
 469         char auxinfo[257];
 470
 471         /* query hardware version */
 472         usb_out_buffer[0] = CMD_GET_VERSION;
 473         result = armjtagew_usb_message(armjtagew_handle, 1, 4 + 15 + 256);
 474
 475         if (result != 0)
 476         {
 477                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)\n", result);
 478                 return ERROR_JTAG_DEVICE_ERROR;
 479         }
 480
 481
 482         memcpy(sn, usb_in_buffer + 4, 15);
 483         sn[15] = '\0';
 484         memcpy(auxinfo, usb_in_buffer + 4+15, 256);
 485         auxinfo[256] = '\0';
 486
 487         LOG_INFO("ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s", \
 488                         usb_in_buffer[1], usb_in_buffer[0], \
 489                         isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X', \
 490                         sn, auxinfo);
 491         return ERROR_OK;
 492 }
 493
 494 COMMAND_HANDLER(armjtagew_handle_armjtagew_info_command)
 495 {
 496         if (armjtagew_get_version_info() == ERROR_OK)
 497         {
 498                 /* attempt to get status */
 499                 armjtagew_get_status();
 500         }
 501
 502         return ERROR_OK;
 503 }
 504
 505 static const struct command_registration armjtagew_command_handlers[] = {
 506         {
 507                 .name = "armjtagew_info",
 508                 .handler = &armjtagew_handle_armjtagew_info_command,
 509                 .mode = COMMAND_EXEC,
 510                 .help = "query armjtagew info",
 511         },
 512         COMMAND_REGISTRATION_DONE
 513 };
 514
 515 struct jtag_interface armjtagew_interface = {
 516                 .name = "arm-jtag-ew",
 517
 518                 .commands = armjtagew_command_handlers,
 519
 520                 .execute_queue = &armjtagew_execute_queue,
 521                 .speed = &armjtagew_speed,
 522                 .khz = &armjtagew_khz,
 523
 524                 .init = &armjtagew_init,
 525                 .quit = &armjtagew_quit,
 526         };
 527
 528 /***************************************************************************/
 529 /* ARM-JTAG-EW tap functions */
 530
 531 /* 2048 is the max value we can use here */
 532 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 533
 534 static int tap_length;
 535 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 536 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 537 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 538
 539 struct pending_scan_result {
 540         int first;      /* First bit position in tdo_buffer to read */
 541         int length; /* Number of bits to read */
 542         struct scan_command *command; /* Corresponding scan command */
 543         uint8_t *buffer;
 544 };
 545
 546 #define MAX_PENDING_SCAN_RESULTS 256
 547
 548 static int pending_scan_results_length;
 549 static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 550
 551 static int last_tms;
 552
 553 static void armjtagew_tap_init(void)
 554 {
 555         tap_length = 0;
 556         pending_scan_results_length = 0;
 557 }
 558
 559 static void armjtagew_tap_ensure_space(int scans, int bits)
 560 {
 561         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 562         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 563
 564         if (scans > available_scans || bits > available_bits)
 565         {
 566                 armjtagew_tap_execute();
 567         }
 568 }
 569
 570 static void armjtagew_tap_append_step(int tms, int tdi)
 571 {
 572         last_tms = tms;
 573         int index = tap_length / 8;
 574
 575         if (index < ARMJTAGEW_TAP_BUFFER_SIZE)
 576         {
 577                 int bit_index = tap_length % 8;
 578                 uint8_t bit = 1 << bit_index;
 579
 580                 if (tms)
 581                 {
 582                         tms_buffer[index] |= bit;
 583                 }
 584                 else
 585                 {
 586                         tms_buffer[index] &= ~bit;
 587                 }
 588
 589                 if (tdi)
 590                 {
 591                         tdi_buffer[index] |= bit;
 592                 }
 593                 else
 594                 {
 595                         tdi_buffer[index] &= ~bit;
 596                 }
 597
 598                 tap_length++;
 599         }
 600         else
 601         {
 602                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 603         }
 604 }
 605
 606 void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command)
 607 {
 608         struct pending_scan_result *pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
 609         int i;
 610
 611         pending_scan_result->first = tap_length;
 612         pending_scan_result->length = length;
 613         pending_scan_result->command = command;
 614         pending_scan_result->buffer = buffer;
 615
 616         for (i = 0; i < length; i++)
 617         {
 618                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 619         }
 620         pending_scan_results_length++;
 621 }
 622
 623 /* Pad and send a tap sequence to the device, and receive the answer.
 624  * For the purpose of padding we assume that we are in idle or pause state. */
 625 static int armjtagew_tap_execute(void)
 626 {
 627         int byte_length;
 628         int tms_offset;
 629         int tdi_offset;
 630         int i;
 631         int result;
 632
 633         if (tap_length > 0)
 634         {
 635                 /* Pad last byte so that tap_length is divisible by 8 */
 636                 while (tap_length % 8 != 0)
 637                 {
 638                         /* More of the last TMS value keeps us in the same state,
 639                          * analogous to free-running JTAG interfaces. */
 640                         armjtagew_tap_append_step(last_tms, 0);
 641                 }
 642
 643                 byte_length = tap_length / 8;
 644
 645                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 646                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 647
 648                 tms_offset = 3;
 649                 for (i = 0; i < byte_length; i++)
 650                 {
 651                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i],8);
 652                 }
 653
 654                 tdi_offset = tms_offset + byte_length;
 655                 for (i = 0; i < byte_length; i++)
 656                 {
 657                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i],8);
 658                 }
 659
 660                 result = armjtagew_usb_message(armjtagew_handle, 3 + 2 * byte_length, byte_length + 4);
 661
 662                 if (result == 0)
 663                 {
 664                         int stat;
 665
 666                         stat = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 667                         if (stat) {
 668                                 LOG_ERROR("armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command", stat);
 669                                 return ERROR_JTAG_QUEUE_FAILED;
 670                         }
 671
 672                         for (i = 0; i < byte_length; i++)
 673                         {
 674                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i],8);
 675                         }
 676
 677                         for (i = 0; i < pending_scan_results_length; i++)
 678                         {
 679                                 struct pending_scan_result *pending_scan_result = &pending_scan_results_buffer[i];
 680                                 uint8_t *buffer = pending_scan_result->buffer;
 681                                 int length = pending_scan_result->length;
 682                                 int first = pending_scan_result->first;
 683                                 struct scan_command *command = pending_scan_result->command;
 684
 685                                 /* Copy to buffer */
 686                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 687
 688                                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 689
 690 #ifdef _DEBUG_USB_COMMS_
 691                                 armjtagew_debug_buffer(buffer, byte_length);
 692 #endif
 693
 694                                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 695                                 {
 696                                         armjtagew_tap_init();
 697                                         return ERROR_JTAG_QUEUE_FAILED;
 698                                 }
 699
 700                                 if (pending_scan_result->buffer != NULL)
 701                                 {
 702                                         free(pending_scan_result->buffer);
 703                                 }
 704                         }
 705                 }
 706                 else
 707                 {
 708                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d", result, byte_length);
 709                         return ERROR_JTAG_QUEUE_FAILED;
 710                 }
 711
 712                 armjtagew_tap_init();
 713         }
 714
 715         return ERROR_OK;
 716 }
 717
 718 /*****************************************************************************/
 719 /* JLink USB low-level functions */
 720
 721 static struct armjtagew* armjtagew_usb_open()
 722 {
 723         usb_init();
 724
 725         const uint16_t vids[] = { USB_VID, 0 };
 726         const uint16_t pids[] = { USB_PID, 0 };
 727         struct usb_dev_handle *dev;
 728         if (jtag_usb_open(vids, pids, &dev) != ERROR_OK)
 729                 return NULL;
 730
 731         struct armjtagew *result = malloc(sizeof(struct armjtagew));
 732         result->usb_handle = dev;
 733
 734 #if 0
 735         /* usb_set_configuration required under win32 */
 736         usb_set_configuration(dev, dev->config[0].bConfigurationValue);
 737 #endif
 738         usb_claim_interface(dev, 0);
 739 #if 0
 740         /*
 741          * This makes problems under Mac OS X. And is not needed
 742          * under Windows. Hopefully this will not break a linux build
 743          */
 744         usb_set_altinterface(dev, 0);
 745 #endif
 746         return result;
 747 }
 748
 749 static void armjtagew_usb_close(struct armjtagew *armjtagew)
 750 {
 751         usb_close(armjtagew->usb_handle);
 752         free(armjtagew);
 753 }
 754
 755 /* Send a message and receive the reply. */
 756 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length)
 757 {
 758         int result;
 759
 760         result = armjtagew_usb_write(armjtagew, out_length);
 761         if (result == out_length)
 762         {
 763                 result = armjtagew_usb_read(armjtagew, in_length);
 764                 if (result != in_length)
 765                 {
 766                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)", in_length, result);
 767                         return -1;
 768                 }
 769         }
 770         else
 771         {
 772                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 773                 return -1;
 774         }
 775         return 0;
 776 }
 777
 778 /* Write data from out_buffer to USB. */
 779 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length)
 780 {
 781         int result;
 782
 783         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE)
 784         {
 785                 LOG_ERROR("armjtagew_write illegal out_length=%d (max=%d)", out_length, ARMJTAGEW_OUT_BUFFER_SIZE);
 786                 return -1;
 787         }
 788
 789         result = usb_bulk_write(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_OUT, \
 790                 (char*)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT);
 791
 792         DEBUG_JTAG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 793
 794 #ifdef _DEBUG_USB_COMMS_
 795         armjtagew_debug_buffer(usb_out_buffer, out_length);
 796 #endif
 797         return result;
 798 }
 799
 800 /* Read data from USB into in_buffer. */
 801 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length)
 802 {
 803         int result = usb_bulk_read(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_IN, \
 804                 (char*)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT);
 805
 806         DEBUG_JTAG_IO("armjtagew_usb_read, result = %d", result);
 807
 808 #ifdef _DEBUG_USB_COMMS_
 809         armjtagew_debug_buffer(usb_in_buffer, result);
 810 #endif
 811         return result;
 812 }
 813
 814
 815 #ifdef _DEBUG_USB_COMMS_
 816 #define BYTES_PER_LINE  16
 817
 818 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 819 {
 820         char line[81];
 821         char s[4];
 822         int i;
 823         int j;
 824
 825         for (i = 0; i < length; i += BYTES_PER_LINE)
 826         {
 827                 snprintf(line, 5, "%04x", i);
 828                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
 829                 {
 830                         snprintf(s, 4, " %02x", buffer[j]);
 831                         strcat(line, s);
 832                 }
 833                 LOG_DEBUG("%s", line);
 834         }
 835 }
 836 #endif
 837