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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 #define USB_VID                                         0x15ba
  31 #define USB_PID                                         0x001e
  32
  33 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  34 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  35
  36 #define ARMJTAGEW_USB_TIMEOUT           2000
  37
  38 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  39 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  40
  41 /* USB command request codes. */
  42 #define CMD_GET_VERSION                         0x00
  43 #define CMD_SELECT_DPIMPL                       0x10
  44 #define CMD_SET_TCK_FREQUENCY           0x11
  45 #define CMD_GET_TCK_FREQUENCY           0x12
  46 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  47 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  48 #define CMD_TAP_SHIFT                           0x17
  49 #define CMD_SET_TAPHW_STATE                     0x20
  50 #define CMD_GET_TAPHW_STATE                     0x21
  51 #define CMD_TGPWR_SETUP                         0x22
  52
  53 /* Global USB buffers */
  54 static uint8_t usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  55 static uint8_t usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  56
  57 /* Queue command functions */
  58 static void armjtagew_end_state(tap_state_t state);
  59 static void armjtagew_state_move(void);
  60 static void armjtagew_path_move(int num_states, tap_state_t *path);
  61 static void armjtagew_runtest(int num_cycles);
  62 static void armjtagew_scan(bool ir_scan,
  63                 enum scan_type type,
  64                 uint8_t *buffer,
  65                 int scan_size,
  66                 struct scan_command *command);
  67 static void armjtagew_reset(int trst, int srst);
  68 /* static void armjtagew_simple_command(uint8_t command); */
  69 static int armjtagew_get_status(void);
  70
  71 /* tap buffer functions */
  72 static void armjtagew_tap_init(void);
  73 static int armjtagew_tap_execute(void);
  74 static void armjtagew_tap_ensure_space(int scans, int bits);
  75 static void armjtagew_tap_append_step(int tms, int tdi);
  76 static void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command);
  77
  78 /* ARM-JTAG-EW lowlevel functions */
  79 struct armjtagew {
  80         struct usb_dev_handle *usb_handle;
  81 };
  82
  83 static struct armjtagew *armjtagew_usb_open(void);
  84 static void armjtagew_usb_close(struct armjtagew *armjtagew);
  85 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length);
  86 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length);
  87 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length);
  88
  89 /* helper functions */
  90 static int armjtagew_get_version_info(void);
  91
  92 #ifdef _DEBUG_USB_COMMS_
  93 static void armjtagew_debug_buffer(uint8_t *buffer, int length);
  94 #endif
  95
  96 static struct armjtagew *armjtagew_handle;
  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                 switch (cmd->type) {
 110                         case JTAG_RUNTEST:
 111                                 DEBUG_JTAG_IO("runtest %i cycles, end in %i",
 112                                                 cmd->cmd.runtest->num_cycles, \
 113                                                 cmd->cmd.runtest->end_state);
 114
 115                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 116                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 117                                 break;
 118
 119                         case JTAG_TLR_RESET:
 120                                 DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 121
 122                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 123                                 armjtagew_state_move();
 124                                 break;
 125
 126                         case JTAG_PATHMOVE:
 127                                 DEBUG_JTAG_IO("pathmove: %i states, end in %i", \
 128                                                 cmd->cmd.pathmove->num_states, \
 129                                                 cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 130
 131                                 armjtagew_path_move(cmd->cmd.pathmove->num_states,
 132                                                 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,
 148                                                 type, buffer,
 149                                                 scan_size, cmd->cmd.scan);
 150                                 break;
 151
 152                         case JTAG_RESET:
 153                                 DEBUG_JTAG_IO("reset trst: %i srst %i",
 154                                                 cmd->cmd.reset->trst,
 155                                                 cmd->cmd.reset->srst);
 156
 157                                 armjtagew_tap_execute();
 158
 159                                 if (cmd->cmd.reset->trst == 1)
 160                                         tap_set_state(TAP_RESET);
 161                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 162                                 break;
 163
 164                         case JTAG_SLEEP:
 165                                 DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 166                                 armjtagew_tap_execute();
 167                                 jtag_sleep(cmd->cmd.sleep->us);
 168                                 break;
 169
 170                         default:
 171                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 172                                 exit(-1);
 173                 }
 174                 cmd = cmd->next;
 175         }
 176
 177         return armjtagew_tap_execute();
 178 }
 179
 180 /* Sets speed in kHz. */
 181 static int armjtagew_speed(int speed)
 182 {
 183         int result;
 184         int speed_real;
 185
 186
 187         usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 188         buf_set_u32(usb_out_buffer + 1, 0, 32, speed*1000);
 189
 190         result = armjtagew_usb_message(armjtagew_handle, 5, 4);
 191
 192         if (result < 0) {
 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                 LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 202                 return ERROR_JTAG_DEVICE_ERROR;
 203         } else
 204                 LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 205
 206         return ERROR_OK;
 207 }
 208
 209 static int armjtagew_khz(int khz, int *jtag_speed)
 210 {
 211         *jtag_speed = khz;
 212
 213         return ERROR_OK;
 214 }
 215
 216 static int armjtagew_speed_div(int speed, int *khz)
 217 {
 218         *khz = speed;
 219
 220         return ERROR_OK;
 221 }
 222
 223 static int armjtagew_init(void)
 224 {
 225         int check_cnt;
 226
 227         armjtagew_handle = armjtagew_usb_open();
 228
 229         if (armjtagew_handle == 0) {
 230                 LOG_ERROR(
 231                         "Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 232                 return ERROR_JTAG_INIT_FAILED;
 233         }
 234
 235         check_cnt = 0;
 236         while (check_cnt < 3) {
 237                 if (armjtagew_get_version_info() == ERROR_OK) {
 238                         /* attempt to get status */
 239                         armjtagew_get_status();
 240                         break;
 241                 }
 242
 243                 check_cnt++;
 244         }
 245
 246         if (check_cnt == 3)
 247                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 248
 249         /* Initial JTAG speed (for reset and initialization): 32 kHz */
 250         armjtagew_speed(32);
 251
 252         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 253
 254         armjtagew_reset(0, 0);
 255         armjtagew_tap_init();
 256
 257         return ERROR_OK;
 258 }
 259
 260 static int armjtagew_quit(void)
 261 {
 262         armjtagew_usb_close(armjtagew_handle);
 263         return ERROR_OK;
 264 }
 265
 266 /**************************************************************************
 267  * Queue command implementations */
 268
 269 static void armjtagew_end_state(tap_state_t state)
 270 {
 271         if (tap_is_state_stable(state))
 272                 tap_set_end_state(state);
 273         else {
 274                 LOG_ERROR("BUG: %i is not a valid end state", state);
 275                 exit(-1);
 276         }
 277 }
 278
 279 /* Goes to the end state. */
 280 static void armjtagew_state_move(void)
 281 {
 282         int i;
 283         int tms = 0;
 284         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 285         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 286
 287         for (i = 0; i < tms_count; i++) {
 288                 tms = (tms_scan >> i) & 1;
 289                 armjtagew_tap_append_step(tms, 0);
 290         }
 291
 292         tap_set_state(tap_get_end_state());
 293 }
 294
 295 static void armjtagew_path_move(int num_states, tap_state_t *path)
 296 {
 297         int i;
 298
 299         for (i = 0; i < num_states; i++) {
 300                 /*
 301                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 302                  * Either handle that here, or update the documentation with examples
 303                  * how to fix that in the configuration files.
 304                  */
 305                 if (path[i] == tap_state_transition(tap_get_state(), false))
 306                         armjtagew_tap_append_step(0, 0);
 307                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 308                         armjtagew_tap_append_step(1, 0);
 309                 else {
 310                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
 311                                 tap_state_name(tap_get_state()), tap_state_name(path[i]));
 312                         exit(-1);
 313                 }
 314
 315                 tap_set_state(path[i]);
 316         }
 317
 318         tap_set_end_state(tap_get_state());
 319 }
 320
 321 static void armjtagew_runtest(int num_cycles)
 322 {
 323         int i;
 324
 325         tap_state_t saved_end_state = tap_get_end_state();
 326
 327         /* only do a state_move when we're not already in IDLE */
 328         if (tap_get_state() != TAP_IDLE) {
 329                 armjtagew_end_state(TAP_IDLE);
 330                 armjtagew_state_move();
 331         }
 332
 333         /* execute num_cycles */
 334         for (i = 0; i < num_cycles; i++)
 335                 armjtagew_tap_append_step(0, 0);
 336
 337         /* finish in end_state */
 338         armjtagew_end_state(saved_end_state);
 339         if (tap_get_state() != tap_get_end_state())
 340                 armjtagew_state_move();
 341 }
 342
 343 static void armjtagew_scan(bool ir_scan,
 344         enum scan_type type,
 345         uint8_t *buffer,
 346         int scan_size,
 347         struct scan_command *command)
 348 {
 349         tap_state_t saved_end_state;
 350
 351         armjtagew_tap_ensure_space(1, scan_size + 8);
 352
 353         saved_end_state = tap_get_end_state();
 354
 355         /* Move to appropriate scan state */
 356         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 357
 358         armjtagew_state_move();
 359         armjtagew_end_state(saved_end_state);
 360
 361         /* Scan */
 362         armjtagew_tap_append_scan(scan_size, buffer, command);
 363
 364         /* We are in Exit1, go to Pause */
 365         armjtagew_tap_append_step(0, 0);
 366
 367         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 368
 369         if (tap_get_state() != tap_get_end_state())
 370                 armjtagew_state_move();
 371 }
 372
 373 static void armjtagew_reset(int trst, int srst)
 374 {
 375         const uint8_t trst_mask = (1u << 5);
 376         const uint8_t srst_mask = (1u << 6);
 377         uint8_t val = 0;
 378         uint8_t outp_en = 0;
 379         uint8_t change_mask = 0;
 380         int result;
 381
 382         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 383
 384         if (srst == 0) {
 385                 val |= srst_mask;
 386                 outp_en &= ~srst_mask;          /* tristate */
 387                 change_mask |= srst_mask;
 388         } else if (srst == 1) {
 389                 val &= ~srst_mask;
 390                 outp_en |= srst_mask;
 391                 change_mask |= srst_mask;
 392         }
 393
 394         if (trst == 0) {
 395                 val |= trst_mask;
 396                 outp_en &= ~trst_mask;          /* tristate */
 397                 change_mask |= trst_mask;
 398         } else if (trst == 1) {
 399                 val &= ~trst_mask;
 400                 outp_en |= trst_mask;
 401                 change_mask |= trst_mask;
 402         }
 403
 404         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 405         usb_out_buffer[1] = val;
 406         usb_out_buffer[2] = outp_en;
 407         usb_out_buffer[3] = change_mask;
 408         result = armjtagew_usb_write(armjtagew_handle, 4);
 409         if (result != 4)
 410                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 411 }
 412
 413 static int armjtagew_get_status(void)
 414 {
 415         int result;
 416
 417         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 418         result = armjtagew_usb_message(armjtagew_handle, 1, 12);
 419
 420         if (result == 0) {
 421                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 422                 LOG_INFO(
 423                         "U_tg = %d mV, U_aux = %d mV, U_tgpwr = %d mV, I_tgpwr = %d mA, D1 = %d, Target power %s %s",
 424                         (int)(buf_get_u32(usb_in_buffer + 0, 0, 16)),
 425                         (int)(buf_get_u32(usb_in_buffer + 2, 0, 16)),
 426                         (int)(buf_get_u32(usb_in_buffer + 4, 0, 16)),
 427                         (int)(buf_get_u32(usb_in_buffer + 6, 0, 16)),
 428                         usb_in_buffer[9],
 429                         usb_in_buffer[11] ? "OVERCURRENT" : "OK",
 430                         usb_in_buffer[10] ? "enabled" : "disabled");
 431
 432                 if (u_tg < 1500)
 433                         LOG_ERROR("Vref too low. Check Target Power");
 434         } else
 435                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)", result);
 436
 437         return ERROR_OK;
 438 }
 439
 440 static int armjtagew_get_version_info(void)
 441 {
 442         int result;
 443         char sn[16];
 444         char auxinfo[257];
 445
 446         /* query hardware version */
 447         usb_out_buffer[0] = CMD_GET_VERSION;
 448         result = armjtagew_usb_message(armjtagew_handle, 1, 4 + 15 + 256);
 449
 450         if (result != 0) {
 451                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)", result);
 452                 return ERROR_JTAG_DEVICE_ERROR;
 453         }
 454
 455         memcpy(sn, usb_in_buffer + 4, 15);
 456         sn[15] = '\0';
 457         memcpy(auxinfo, usb_in_buffer + 4+15, 256);
 458         auxinfo[256] = '\0';
 459
 460         LOG_INFO(
 461                 "ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s", \
 462                 usb_in_buffer[1],
 463                 usb_in_buffer[0], \
 464                 isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X', \
 465                 sn,
 466                 auxinfo);
 467
 468         if (1 != usb_in_buffer[1] || 6 != usb_in_buffer[0])
 469                 LOG_WARNING(
 470                         "ARM-JTAG-EW firmware version %d.%d is untested with this version of OpenOCD. You might experience unexpected behavior.",
 471                         usb_in_buffer[1],
 472                         usb_in_buffer[0]);
 473         return ERROR_OK;
 474 }
 475
 476 COMMAND_HANDLER(armjtagew_handle_armjtagew_info_command)
 477 {
 478         if (armjtagew_get_version_info() == ERROR_OK) {
 479                 /* attempt to get status */
 480                 armjtagew_get_status();
 481         }
 482
 483         return ERROR_OK;
 484 }
 485
 486 static const struct command_registration armjtagew_command_handlers[] = {
 487         {
 488                 .name = "armjtagew_info",
 489                 .handler = &armjtagew_handle_armjtagew_info_command,
 490                 .mode = COMMAND_EXEC,
 491                 .help = "query armjtagew info",
 492         },
 493         COMMAND_REGISTRATION_DONE
 494 };
 495
 496 struct jtag_interface armjtagew_interface = {
 497         .name = "arm-jtag-ew",
 498         .commands = armjtagew_command_handlers,
 499         .transports = jtag_only,
 500         .execute_queue = armjtagew_execute_queue,
 501         .speed = armjtagew_speed,
 502         .speed_div = armjtagew_speed_div,
 503         .khz = armjtagew_khz,
 504         .init = armjtagew_init,
 505         .quit = armjtagew_quit,
 506 };
 507
 508 /**************************************************************************
 509  * ARM-JTAG-EW tap functions */
 510
 511 /* 2048 is the max value we can use here */
 512 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 513
 514 static int tap_length;
 515 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 516 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 517 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 518
 519 struct pending_scan_result {
 520         int first;      /* First bit position in tdo_buffer to read */
 521         int length;     /* Number of bits to read */
 522         struct scan_command *command;   /* Corresponding scan command */
 523         uint8_t *buffer;
 524 };
 525
 526 #define MAX_PENDING_SCAN_RESULTS 256
 527
 528 static int pending_scan_results_length;
 529 static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 530
 531 static int last_tms;
 532
 533 static void armjtagew_tap_init(void)
 534 {
 535         tap_length = 0;
 536         pending_scan_results_length = 0;
 537 }
 538
 539 static void armjtagew_tap_ensure_space(int scans, int bits)
 540 {
 541         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 542         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 543
 544         if (scans > available_scans || bits > available_bits)
 545                 armjtagew_tap_execute();
 546 }
 547
 548 static void armjtagew_tap_append_step(int tms, int tdi)
 549 {
 550         last_tms = tms;
 551         int index_local = tap_length / 8;
 552
 553         if (index_local < ARMJTAGEW_TAP_BUFFER_SIZE) {
 554                 int bit_index = tap_length % 8;
 555                 uint8_t bit = 1 << bit_index;
 556
 557                 if (tms)
 558                         tms_buffer[index_local] |= bit;
 559                 else
 560                         tms_buffer[index_local] &= ~bit;
 561
 562                 if (tdi)
 563                         tdi_buffer[index_local] |= bit;
 564                 else
 565                         tdi_buffer[index_local] &= ~bit;
 566
 567                 tap_length++;
 568         } else
 569                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 570 }
 571
 572 void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command)
 573 {
 574         struct pending_scan_result *pending_scan_result =
 575                 &pending_scan_results_buffer[pending_scan_results_length];
 576         int i;
 577
 578         pending_scan_result->first = tap_length;
 579         pending_scan_result->length = length;
 580         pending_scan_result->command = command;
 581         pending_scan_result->buffer = buffer;
 582
 583         for (i = 0; i < length; i++)
 584                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 585         pending_scan_results_length++;
 586 }
 587
 588 /* Pad and send a tap sequence to the device, and receive the answer.
 589  * For the purpose of padding we assume that we are in idle or pause state. */
 590 static int armjtagew_tap_execute(void)
 591 {
 592         int byte_length;
 593         int tms_offset;
 594         int tdi_offset;
 595         int i;
 596         int result;
 597
 598         if (tap_length > 0) {
 599                 /* Pad last byte so that tap_length is divisible by 8 */
 600                 while (tap_length % 8 != 0) {
 601                         /* More of the last TMS value keeps us in the same state,
 602                          * analogous to free-running JTAG interfaces. */
 603                         armjtagew_tap_append_step(last_tms, 0);
 604                 }
 605
 606                 byte_length = tap_length / 8;
 607
 608                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 609                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 610
 611                 tms_offset = 3;
 612                 for (i = 0; i < byte_length; i++)
 613                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i], 8);
 614
 615                 tdi_offset = tms_offset + byte_length;
 616                 for (i = 0; i < byte_length; i++)
 617                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i], 8);
 618
 619                 result = armjtagew_usb_message(armjtagew_handle,
 620                                 3 + 2 * byte_length,
 621                                 byte_length + 4);
 622
 623                 if (result == 0) {
 624                         int stat_local;
 625
 626                         stat_local = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 627                         if (stat_local) {
 628                                 LOG_ERROR(
 629                                         "armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command",
 630                                         stat_local);
 631                                 return ERROR_JTAG_QUEUE_FAILED;
 632                         }
 633
 634                         for (i = 0; i < byte_length; i++)
 635                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i], 8);
 636
 637                         for (i = 0; i < pending_scan_results_length; i++) {
 638                                 struct pending_scan_result *pending_scan_result =
 639                                         &pending_scan_results_buffer[i];
 640                                 uint8_t *buffer = pending_scan_result->buffer;
 641                                 int length = pending_scan_result->length;
 642                                 int first = pending_scan_result->first;
 643                                 struct scan_command *command = pending_scan_result->command;
 644
 645                                 /* Copy to buffer */
 646                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 647
 648                                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 649
 650 #ifdef _DEBUG_USB_COMMS_
 651                                 armjtagew_debug_buffer(buffer, byte_length);
 652 #endif
 653
 654                                 if (jtag_read_buffer(buffer, command) != ERROR_OK) {
 655                                         armjtagew_tap_init();
 656                                         return ERROR_JTAG_QUEUE_FAILED;
 657                                 }
 658
 659                                 if (pending_scan_result->buffer != NULL)
 660                                         free(pending_scan_result->buffer);
 661                         }
 662                 } else {
 663                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d",
 664                                 result,
 665                                 byte_length);
 666                         return ERROR_JTAG_QUEUE_FAILED;
 667                 }
 668
 669                 armjtagew_tap_init();
 670         }
 671
 672         return ERROR_OK;
 673 }
 674
 675 /****************************************************************************
 676  * JLink USB low-level functions */
 677
 678 static struct armjtagew *armjtagew_usb_open()
 679 {
 680         usb_init();
 681
 682         const uint16_t vids[] = { USB_VID, 0 };
 683         const uint16_t pids[] = { USB_PID, 0 };
 684         struct usb_dev_handle *dev;
 685         if (jtag_usb_open(vids, pids, &dev) != ERROR_OK)
 686                 return NULL;
 687
 688         struct armjtagew *result = malloc(sizeof(struct armjtagew));
 689         result->usb_handle = dev;
 690
 691 #if 0
 692         /* usb_set_configuration required under win32 */
 693         usb_set_configuration(dev, dev->config[0].bConfigurationValue);
 694 #endif
 695         usb_claim_interface(dev, 0);
 696 #if 0
 697         /*
 698          * This makes problems under Mac OS X. And is not needed
 699          * under Windows. Hopefully this will not break a linux build
 700          */
 701         usb_set_altinterface(dev, 0);
 702 #endif
 703         return result;
 704 }
 705
 706 static void armjtagew_usb_close(struct armjtagew *armjtagew)
 707 {
 708         usb_close(armjtagew->usb_handle);
 709         free(armjtagew);
 710 }
 711
 712 /* Send a message and receive the reply. */
 713 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length)
 714 {
 715         int result;
 716
 717         result = armjtagew_usb_write(armjtagew, out_length);
 718         if (result == out_length) {
 719                 result = armjtagew_usb_read(armjtagew, in_length);
 720                 if (result != in_length) {
 721                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)",
 722                                 in_length,
 723                                 result);
 724                         return -1;
 725                 }
 726         } else {
 727                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 728                 return -1;
 729         }
 730         return 0;
 731 }
 732
 733 /* Write data from out_buffer to USB. */
 734 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length)
 735 {
 736         int result;
 737
 738         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE) {
 739                 LOG_ERROR("armjtagew_write illegal out_length=%d (max=%d)",
 740                         out_length,
 741                         ARMJTAGEW_OUT_BUFFER_SIZE);
 742                 return -1;
 743         }
 744
 745         result = usb_bulk_write(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_OUT, \
 746                         (char *)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT);
 747
 748         DEBUG_JTAG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 749
 750 #ifdef _DEBUG_USB_COMMS_
 751         armjtagew_debug_buffer(usb_out_buffer, out_length);
 752 #endif
 753         return result;
 754 }
 755
 756 /* Read data from USB into in_buffer. */
 757 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length)
 758 {
 759         int result = usb_bulk_read(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_IN, \
 760                         (char *)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT);
 761
 762         DEBUG_JTAG_IO("armjtagew_usb_read, result = %d", result);
 763
 764 #ifdef _DEBUG_USB_COMMS_
 765         armjtagew_debug_buffer(usb_in_buffer, result);
 766 #endif
 767         return result;
 768 }
 769
 770 #ifdef _DEBUG_USB_COMMS_
 771 #define BYTES_PER_LINE  16
 772
 773 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 774 {
 775         char line[81];
 776         char s[4];
 777         int i;
 778         int j;
 779
 780         for (i = 0; i < length; i += BYTES_PER_LINE) {
 781                 snprintf(line, 5, "%04x", i);
 782                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++) {
 783                         snprintf(s, 4, " %02x", buffer[j]);
 784                         strcat(line, s);
 785                 }
 786                 LOG_DEBUG("%s", line);
 787
 788                 /* Prevent GDB timeout (writing to log might take some time) */
 789                 keep_alive();
 790         }
 791 }
 792 #endif