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