src/jtag/drivers/arm-jtag-ew.c

   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 <jtag/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_TLR_RESET:
 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*1000);
 188
 189     result = armjtagew_usb_message(armjtagew_handle, 5, 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) / 1000;
 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_speed_div(int speed, int* khz)
 222 {
 223         *khz = speed;
 224
 225         return ERROR_OK;
 226 }
 227
 228
 229 static int armjtagew_init(void)
 230 {
 231         int check_cnt;
 232
 233         armjtagew_handle = armjtagew_usb_open();
 234
 235         if (armjtagew_handle == 0)
 236         {
 237                 LOG_ERROR("Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 238                 return ERROR_JTAG_INIT_FAILED;
 239         }
 240
 241         check_cnt = 0;
 242         while (check_cnt < 3)
 243         {
 244                 if (armjtagew_get_version_info() == ERROR_OK)
 245                 {
 246                         /* attempt to get status */
 247                         armjtagew_get_status();
 248                         break;
 249                 }
 250
 251                 check_cnt++;
 252         }
 253
 254         if (check_cnt == 3)
 255         {
 256                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 257         }
 258
 259         // Initial JTAG speed (for reset and initialization): 32 kHz
 260         armjtagew_speed(32);
 261
 262         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 263
 264         armjtagew_reset(0, 0);
 265         armjtagew_tap_init();
 266
 267         return ERROR_OK;
 268 }
 269
 270 static int armjtagew_quit(void)
 271 {
 272         armjtagew_usb_close(armjtagew_handle);
 273         return ERROR_OK;
 274 }
 275
 276 /***************************************************************************/
 277 /* Queue command implementations */
 278
 279 static void armjtagew_end_state(tap_state_t state)
 280 {
 281         if (tap_is_state_stable(state))
 282         {
 283                 tap_set_end_state(state);
 284         }
 285         else
 286         {
 287                 LOG_ERROR("BUG: %i is not a valid end state", state);
 288                 exit(-1);
 289         }
 290 }
 291
 292 /* Goes to the end state. */
 293 static void armjtagew_state_move(void)
 294 {
 295         int i;
 296         int tms = 0;
 297         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 298         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 299
 300         for (i = 0; i < tms_count; i++)
 301         {
 302                 tms = (tms_scan >> i) & 1;
 303                 armjtagew_tap_append_step(tms, 0);
 304         }
 305
 306         tap_set_state(tap_get_end_state());
 307 }
 308
 309 static void armjtagew_path_move(int num_states, tap_state_t *path)
 310 {
 311         int i;
 312
 313         for (i = 0; i < num_states; i++)
 314         {
 315                 /*
 316                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 317                  * Either handle that here, or update the documentation with examples
 318                  * how to fix that in the configuration files.
 319                  */
 320                 if (path[i] == tap_state_transition(tap_get_state(), false))
 321                 {
 322                         armjtagew_tap_append_step(0, 0);
 323                 }
 324                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 325                 {
 326                         armjtagew_tap_append_step(1, 0);
 327                 }
 328                 else
 329                 {
 330                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 331                         exit(-1);
 332                 }
 333
 334                 tap_set_state(path[i]);
 335         }
 336
 337         tap_set_end_state(tap_get_state());
 338 }
 339
 340 static void armjtagew_runtest(int num_cycles)
 341 {
 342         int i;
 343
 344         tap_state_t saved_end_state = tap_get_end_state();
 345
 346         /* only do a state_move when we're not already in IDLE */
 347         if (tap_get_state() != TAP_IDLE)
 348         {
 349                 armjtagew_end_state(TAP_IDLE);
 350                 armjtagew_state_move();
 351         }
 352
 353         /* execute num_cycles */
 354         for (i = 0; i < num_cycles; i++)
 355         {
 356                 armjtagew_tap_append_step(0, 0);
 357         }
 358
 359         /* finish in end_state */
 360         armjtagew_end_state(saved_end_state);
 361         if (tap_get_state() != tap_get_end_state())
 362         {
 363                 armjtagew_state_move();
 364         }
 365 }
 366
 367 static void armjtagew_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, struct scan_command *command)
 368 {
 369         tap_state_t saved_end_state;
 370
 371         armjtagew_tap_ensure_space(1, scan_size + 8);
 372
 373         saved_end_state = tap_get_end_state();
 374
 375         /* Move to appropriate scan state */
 376         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 377
 378         armjtagew_state_move();
 379         armjtagew_end_state(saved_end_state);
 380
 381         /* Scan */
 382         armjtagew_tap_append_scan(scan_size, buffer, command);
 383
 384         /* We are in Exit1, go to Pause */
 385         armjtagew_tap_append_step(0, 0);
 386
 387         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 388
 389         if (tap_get_state() != tap_get_end_state())
 390         {
 391                 armjtagew_state_move();
 392         }
 393 }
 394
 395 static void armjtagew_reset(int trst, int srst)
 396 {
 397         const uint8_t trst_mask = (1u << 5);
 398         const uint8_t srst_mask = (1u << 6);
 399         uint8_t val = 0;
 400         uint8_t outp_en = 0;
 401         uint8_t change_mask = 0;
 402         int result;
 403
 404         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 405
 406         if (srst == 0)
 407         {
 408                 val |= srst_mask;
 409                 outp_en &= ~srst_mask;          /* tristate */
 410                 change_mask |= srst_mask;
 411         }
 412         else if (srst == 1)
 413         {
 414                 val &= ~srst_mask;
 415                 outp_en |= srst_mask;
 416                 change_mask |= srst_mask;
 417         }
 418
 419         if (trst == 0)
 420         {
 421                 val |= trst_mask;
 422                 outp_en &= ~trst_mask;          /* tristate */
 423                 change_mask |= trst_mask;
 424         }
 425         else if (trst == 1)
 426         {
 427                 val &= ~trst_mask;
 428                 outp_en |= trst_mask;
 429                 change_mask |= trst_mask;
 430         }
 431
 432         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 433         usb_out_buffer[1] = val;
 434         usb_out_buffer[2] = outp_en;
 435         usb_out_buffer[3] = change_mask;
 436         result = armjtagew_usb_write(armjtagew_handle, 4);
 437         if (result != 4)
 438         {
 439                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 440         }
 441 }
 442
 443
 444 static int armjtagew_get_status(void)
 445 {
 446         int result;
 447
 448         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 449         result = armjtagew_usb_message(armjtagew_handle, 1, 12);
 450
 451         if (result == 0)
 452         {
 453                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 454                 LOG_INFO("U_tg = %d mV, U_aux = %d mV, U_tgpwr = %d mV, I_tgpwr = %d mA, D1 = %d, Target power %s %s",
 455                          (int)(buf_get_u32(usb_in_buffer + 0, 0, 16)),
 456                          (int)(buf_get_u32(usb_in_buffer + 2, 0, 16)),
 457                          (int)(buf_get_u32(usb_in_buffer + 4, 0, 16)),
 458                          (int)(buf_get_u32(usb_in_buffer + 6, 0, 16)),
 459                          usb_in_buffer[9],
 460                          usb_in_buffer[11] ? "OVERCURRENT" : "OK",
 461                          usb_in_buffer[10] ? "enabled" : "disabled");
 462
 463                 if (u_tg < 1500)
 464                 {
 465                         LOG_ERROR("Vref too low. Check Target Power");
 466                 }
 467         }
 468         else
 469         {
 470                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)", result);
 471         }
 472
 473         return ERROR_OK;
 474 }
 475
 476 static int armjtagew_get_version_info(void)
 477 {
 478         int result;
 479         char sn[16];
 480         char auxinfo[257];
 481
 482         /* query hardware version */
 483         usb_out_buffer[0] = CMD_GET_VERSION;
 484         result = armjtagew_usb_message(armjtagew_handle, 1, 4 + 15 + 256);
 485
 486         if (result != 0)
 487         {
 488                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)", result);
 489                 return ERROR_JTAG_DEVICE_ERROR;
 490         }
 491
 492
 493         memcpy(sn, usb_in_buffer + 4, 15);
 494         sn[15] = '\0';
 495         memcpy(auxinfo, usb_in_buffer + 4+15, 256);
 496         auxinfo[256] = '\0';
 497
 498         LOG_INFO("ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s", \
 499                         usb_in_buffer[1], usb_in_buffer[0], \
 500                         isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X', \
 501                         sn, auxinfo);
 502
 503         if (1 != usb_in_buffer[1] || 6 != usb_in_buffer[0])
 504         {
 505                 LOG_WARNING("ARM-JTAG-EW firmware version %d.%d is untested with this version of OpenOCD. You might experience unexpected behavior.", usb_in_buffer[1], usb_in_buffer[0]);
 506         }
 507         return ERROR_OK;
 508 }
 509
 510 COMMAND_HANDLER(armjtagew_handle_armjtagew_info_command)
 511 {
 512         if (armjtagew_get_version_info() == ERROR_OK)
 513         {
 514                 /* attempt to get status */
 515                 armjtagew_get_status();
 516         }
 517
 518         return ERROR_OK;
 519 }
 520
 521 static const struct command_registration armjtagew_command_handlers[] = {
 522         {
 523                 .name = "armjtagew_info",
 524                 .handler = &armjtagew_handle_armjtagew_info_command,
 525                 .mode = COMMAND_EXEC,
 526                 .help = "query armjtagew info",
 527         },
 528         COMMAND_REGISTRATION_DONE
 529 };
 530
 531 struct jtag_interface armjtagew_interface = {
 532         .name = "arm-jtag-ew",
 533         .commands = armjtagew_command_handlers,
 534         .transports = jtag_only,
 535
 536         .execute_queue = armjtagew_execute_queue,
 537         .speed = armjtagew_speed,
 538         .speed_div = armjtagew_speed_div,
 539         .khz = armjtagew_khz,
 540         .init = armjtagew_init,
 541         .quit = armjtagew_quit,
 542 };
 543
 544 /***************************************************************************/
 545 /* ARM-JTAG-EW tap functions */
 546
 547 /* 2048 is the max value we can use here */
 548 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 549
 550 static int tap_length;
 551 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 552 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 553 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 554
 555 struct pending_scan_result {
 556         int first;      /* First bit position in tdo_buffer to read */
 557         int length; /* Number of bits to read */
 558         struct scan_command *command; /* Corresponding scan command */
 559         uint8_t *buffer;
 560 };
 561
 562 #define MAX_PENDING_SCAN_RESULTS 256
 563
 564 static int pending_scan_results_length;
 565 static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 566
 567 static int last_tms;
 568
 569 static void armjtagew_tap_init(void)
 570 {
 571         tap_length = 0;
 572         pending_scan_results_length = 0;
 573 }
 574
 575 static void armjtagew_tap_ensure_space(int scans, int bits)
 576 {
 577         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 578         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 579
 580         if (scans > available_scans || bits > available_bits)
 581         {
 582                 armjtagew_tap_execute();
 583         }
 584 }
 585
 586 static void armjtagew_tap_append_step(int tms, int tdi)
 587 {
 588         last_tms = tms;
 589         int index_local = tap_length / 8;
 590
 591         if (index_local < ARMJTAGEW_TAP_BUFFER_SIZE)
 592         {
 593                 int bit_index = tap_length % 8;
 594                 uint8_t bit = 1 << bit_index;
 595
 596                 if (tms)
 597                 {
 598                         tms_buffer[index_local] |= bit;
 599                 }
 600                 else
 601                 {
 602                         tms_buffer[index_local] &= ~bit;
 603                 }
 604
 605                 if (tdi)
 606                 {
 607                         tdi_buffer[index_local] |= bit;
 608                 }
 609                 else
 610                 {
 611                         tdi_buffer[index_local] &= ~bit;
 612                 }
 613
 614                 tap_length++;
 615         }
 616         else
 617         {
 618                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 619         }
 620 }
 621
 622 void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command)
 623 {
 624         struct pending_scan_result *pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
 625         int i;
 626
 627         pending_scan_result->first = tap_length;
 628         pending_scan_result->length = length;
 629         pending_scan_result->command = command;
 630         pending_scan_result->buffer = buffer;
 631
 632         for (i = 0; i < length; i++)
 633         {
 634                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 635         }
 636         pending_scan_results_length++;
 637 }
 638
 639 /* Pad and send a tap sequence to the device, and receive the answer.
 640  * For the purpose of padding we assume that we are in idle or pause state. */
 641 static int armjtagew_tap_execute(void)
 642 {
 643         int byte_length;
 644         int tms_offset;
 645         int tdi_offset;
 646         int i;
 647         int result;
 648
 649         if (tap_length > 0)
 650         {
 651                 /* Pad last byte so that tap_length is divisible by 8 */
 652                 while (tap_length % 8 != 0)
 653                 {
 654                         /* More of the last TMS value keeps us in the same state,
 655                          * analogous to free-running JTAG interfaces. */
 656                         armjtagew_tap_append_step(last_tms, 0);
 657                 }
 658
 659                 byte_length = tap_length / 8;
 660
 661                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 662                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 663
 664                 tms_offset = 3;
 665                 for (i = 0; i < byte_length; i++)
 666                 {
 667                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i],8);
 668                 }
 669
 670                 tdi_offset = tms_offset + byte_length;
 671                 for (i = 0; i < byte_length; i++)
 672                 {
 673                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i],8);
 674                 }
 675
 676                 result = armjtagew_usb_message(armjtagew_handle, 3 + 2 * byte_length, byte_length + 4);
 677
 678                 if (result == 0)
 679                 {
 680                         int stat_local;
 681
 682                         stat_local = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 683                         if (stat_local) {
 684                                 LOG_ERROR("armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command", stat_local);
 685                                 return ERROR_JTAG_QUEUE_FAILED;
 686                         }
 687
 688                         for (i = 0; i < byte_length; i++)
 689                         {
 690                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i],8);
 691                         }
 692
 693                         for (i = 0; i < pending_scan_results_length; i++)
 694                         {
 695                                 struct pending_scan_result *pending_scan_result = &pending_scan_results_buffer[i];
 696                                 uint8_t *buffer = pending_scan_result->buffer;
 697                                 int length = pending_scan_result->length;
 698                                 int first = pending_scan_result->first;
 699                                 struct scan_command *command = pending_scan_result->command;
 700
 701                                 /* Copy to buffer */
 702                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 703
 704                                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 705
 706 #ifdef _DEBUG_USB_COMMS_
 707                                 armjtagew_debug_buffer(buffer, byte_length);
 708 #endif
 709
 710                                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 711                                 {
 712                                         armjtagew_tap_init();
 713                                         return ERROR_JTAG_QUEUE_FAILED;
 714                                 }
 715
 716                                 if (pending_scan_result->buffer != NULL)
 717                                 {
 718                                         free(pending_scan_result->buffer);
 719                                 }
 720                         }
 721                 }
 722                 else
 723                 {
 724                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d", result, byte_length);
 725                         return ERROR_JTAG_QUEUE_FAILED;
 726                 }
 727
 728                 armjtagew_tap_init();
 729         }
 730
 731         return ERROR_OK;
 732 }
 733
 734 /*****************************************************************************/
 735 /* JLink USB low-level functions */
 736
 737 static struct armjtagew* armjtagew_usb_open()
 738 {
 739         usb_init();
 740
 741         const uint16_t vids[] = { USB_VID, 0 };
 742         const uint16_t pids[] = { USB_PID, 0 };
 743         struct usb_dev_handle *dev;
 744         if (jtag_usb_open(vids, pids, &dev) != ERROR_OK)
 745                 return NULL;
 746
 747         struct armjtagew *result = malloc(sizeof(struct armjtagew));
 748         result->usb_handle = dev;
 749
 750 #if 0
 751         /* usb_set_configuration required under win32 */
 752         usb_set_configuration(dev, dev->config[0].bConfigurationValue);
 753 #endif
 754         usb_claim_interface(dev, 0);
 755 #if 0
 756         /*
 757          * This makes problems under Mac OS X. And is not needed
 758          * under Windows. Hopefully this will not break a linux build
 759          */
 760         usb_set_altinterface(dev, 0);
 761 #endif
 762         return result;
 763 }
 764
 765 static void armjtagew_usb_close(struct armjtagew *armjtagew)
 766 {
 767         usb_close(armjtagew->usb_handle);
 768         free(armjtagew);
 769 }
 770
 771 /* Send a message and receive the reply. */
 772 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length)
 773 {
 774         int result;
 775
 776         result = armjtagew_usb_write(armjtagew, out_length);
 777         if (result == out_length)
 778         {
 779                 result = armjtagew_usb_read(armjtagew, in_length);
 780                 if (result != in_length)
 781                 {
 782                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)", in_length, result);
 783                         return -1;
 784                 }
 785         }
 786         else
 787         {
 788                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 789                 return -1;
 790         }
 791         return 0;
 792 }
 793
 794 /* Write data from out_buffer to USB. */
 795 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length)
 796 {
 797         int result;
 798
 799         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE)
 800         {
 801                 LOG_ERROR("armjtagew_write illegal out_length=%d (max=%d)", out_length, ARMJTAGEW_OUT_BUFFER_SIZE);
 802                 return -1;
 803         }
 804
 805         result = usb_bulk_write(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_OUT, \
 806                 (char*)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT);
 807
 808         DEBUG_JTAG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 809
 810 #ifdef _DEBUG_USB_COMMS_
 811         armjtagew_debug_buffer(usb_out_buffer, out_length);
 812 #endif
 813         return result;
 814 }
 815
 816 /* Read data from USB into in_buffer. */
 817 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length)
 818 {
 819         int result = usb_bulk_read(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_IN, \
 820                 (char*)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT);
 821
 822         DEBUG_JTAG_IO("armjtagew_usb_read, result = %d", result);
 823
 824 #ifdef _DEBUG_USB_COMMS_
 825         armjtagew_debug_buffer(usb_in_buffer, result);
 826 #endif
 827         return result;
 828 }
 829
 830
 831 #ifdef _DEBUG_USB_COMMS_
 832 #define BYTES_PER_LINE  16
 833
 834 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 835 {
 836         char line[81];
 837         char s[4];
 838         int i;
 839         int j;
 840
 841         for (i = 0; i < length; i += BYTES_PER_LINE)
 842         {
 843                 snprintf(line, 5, "%04x", i);
 844                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
 845                 {
 846                         snprintf(s, 4, " %02x", buffer[j]);
 847                         strcat(line, s);
 848                 }
 849                 LOG_DEBUG("%s", line);
 850
 851                 // Prevent GDB timeout (writing to log might take some time)
 852                 keep_alive();
 853         }
 854 }
 855 #endif
 856