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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, see <http://www.gnu.org/licenses/>. *
  17  ***************************************************************************/
  18
  19 #ifdef HAVE_CONFIG_H
  20 #include "config.h"
  21 #endif
  22
  23 #include <jtag/interface.h>
  24 #include <jtag/commands.h>
  25 #include <usb.h>
  26 #include "usb_common.h"
  27
  28 #define USB_VID                                         0x15ba
  29 #define USB_PID                                         0x001e
  30
  31 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  32 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  33
  34 #define ARMJTAGEW_USB_TIMEOUT           2000
  35
  36 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  37 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  38
  39 /* USB command request codes. */
  40 #define CMD_GET_VERSION                         0x00
  41 #define CMD_SELECT_DPIMPL                       0x10
  42 #define CMD_SET_TCK_FREQUENCY           0x11
  43 #define CMD_GET_TCK_FREQUENCY           0x12
  44 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  45 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  46 #define CMD_TAP_SHIFT                           0x17
  47 #define CMD_SET_TAPHW_STATE                     0x20
  48 #define CMD_GET_TAPHW_STATE                     0x21
  49 #define CMD_TGPWR_SETUP                         0x22
  50
  51 /* Global USB buffers */
  52 static uint8_t usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  53 static uint8_t usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  54
  55 /* Queue command functions */
  56 static void armjtagew_end_state(tap_state_t state);
  57 static void armjtagew_state_move(void);
  58 static void armjtagew_path_move(int num_states, tap_state_t *path);
  59 static void armjtagew_runtest(int num_cycles);
  60 static void armjtagew_scan(bool ir_scan,
  61                 enum scan_type type,
  62                 uint8_t *buffer,
  63                 int scan_size,
  64                 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  * External interface implementation */
  98
  99 static int armjtagew_execute_queue(void)
 100 {
 101         struct jtag_command *cmd = jtag_command_queue;
 102         int scan_size;
 103         enum scan_type type;
 104         uint8_t *buffer;
 105
 106         while (cmd != NULL) {
 107                 switch (cmd->type) {
 108                         case JTAG_RUNTEST:
 109                                 LOG_DEBUG_IO("runtest %i cycles, end in %i",
 110                                                 cmd->cmd.runtest->num_cycles, \
 111                                                 cmd->cmd.runtest->end_state);
 112
 113                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 114                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 115                                 break;
 116
 117                         case JTAG_TLR_RESET:
 118                                 LOG_DEBUG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 119
 120                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 121                                 armjtagew_state_move();
 122                                 break;
 123
 124                         case JTAG_PATHMOVE:
 125                                 LOG_DEBUG_IO("pathmove: %i states, end in %i", \
 126                                                 cmd->cmd.pathmove->num_states, \
 127                                                 cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 128
 129                                 armjtagew_path_move(cmd->cmd.pathmove->num_states,
 130                                                 cmd->cmd.pathmove->path);
 131                                 break;
 132
 133                         case JTAG_SCAN:
 134                                 LOG_DEBUG_IO("scan end in %i", cmd->cmd.scan->end_state);
 135
 136                                 armjtagew_end_state(cmd->cmd.scan->end_state);
 137
 138                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 139                                 LOG_DEBUG_IO("scan input, length = %d", scan_size);
 140
 141 #ifdef _DEBUG_USB_COMMS_
 142                                 armjtagew_debug_buffer(buffer, (scan_size + 7) / 8);
 143 #endif
 144                                 type = jtag_scan_type(cmd->cmd.scan);
 145                                 armjtagew_scan(cmd->cmd.scan->ir_scan,
 146                                                 type, buffer,
 147                                                 scan_size, cmd->cmd.scan);
 148                                 break;
 149
 150                         case JTAG_RESET:
 151                                 LOG_DEBUG_IO("reset trst: %i srst %i",
 152                                                 cmd->cmd.reset->trst,
 153                                                 cmd->cmd.reset->srst);
 154
 155                                 armjtagew_tap_execute();
 156
 157                                 if (cmd->cmd.reset->trst == 1)
 158                                         tap_set_state(TAP_RESET);
 159                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 160                                 break;
 161
 162                         case JTAG_SLEEP:
 163                                 LOG_DEBUG_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 /* Sets speed in kHz. */
 179 static int armjtagew_speed(int speed)
 180 {
 181         int result;
 182         int speed_real;
 183
 184
 185         usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 186         buf_set_u32(usb_out_buffer + 1, 0, 32, speed*1000);
 187
 188         result = armjtagew_usb_message(armjtagew_handle, 5, 4);
 189
 190         if (result < 0) {
 191                 LOG_ERROR("ARM-JTAG-EW setting speed failed (%d)", result);
 192                 return ERROR_JTAG_DEVICE_ERROR;
 193         }
 194
 195         usb_out_buffer[0] = CMD_GET_TCK_FREQUENCY;
 196         result = armjtagew_usb_message(armjtagew_handle, 1, 4);
 197         speed_real = (int)buf_get_u32(usb_in_buffer, 0, 32) / 1000;
 198         if (result < 0) {
 199                 LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 200                 return ERROR_JTAG_DEVICE_ERROR;
 201         } else
 202                 LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 203
 204         return ERROR_OK;
 205 }
 206
 207 static int armjtagew_khz(int khz, int *jtag_speed)
 208 {
 209         *jtag_speed = khz;
 210
 211         return ERROR_OK;
 212 }
 213
 214 static int armjtagew_speed_div(int speed, int *khz)
 215 {
 216         *khz = speed;
 217
 218         return ERROR_OK;
 219 }
 220
 221 static int armjtagew_init(void)
 222 {
 223         int check_cnt;
 224
 225         armjtagew_handle = armjtagew_usb_open();
 226
 227         if (armjtagew_handle == 0) {
 228                 LOG_ERROR(
 229                         "Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 230                 return ERROR_JTAG_INIT_FAILED;
 231         }
 232
 233         check_cnt = 0;
 234         while (check_cnt < 3) {
 235                 if (armjtagew_get_version_info() == ERROR_OK) {
 236                         /* attempt to get status */
 237                         armjtagew_get_status();
 238                         break;
 239                 }
 240
 241                 check_cnt++;
 242         }
 243
 244         if (check_cnt == 3)
 245                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 246
 247         /* Initial JTAG speed (for reset and initialization): 32 kHz */
 248         armjtagew_speed(32);
 249
 250         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 251
 252         armjtagew_reset(0, 0);
 253         armjtagew_tap_init();
 254
 255         return ERROR_OK;
 256 }
 257
 258 static int armjtagew_quit(void)
 259 {
 260         armjtagew_usb_close(armjtagew_handle);
 261         return ERROR_OK;
 262 }
 263
 264 /**************************************************************************
 265  * Queue command implementations */
 266
 267 static void armjtagew_end_state(tap_state_t state)
 268 {
 269         if (tap_is_state_stable(state))
 270                 tap_set_end_state(state);
 271         else {
 272                 LOG_ERROR("BUG: %i is not a valid end state", state);
 273                 exit(-1);
 274         }
 275 }
 276
 277 /* Goes to the end state. */
 278 static void armjtagew_state_move(void)
 279 {
 280         int i;
 281         int tms = 0;
 282         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 283         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 284
 285         for (i = 0; i < tms_count; i++) {
 286                 tms = (tms_scan >> i) & 1;
 287                 armjtagew_tap_append_step(tms, 0);
 288         }
 289
 290         tap_set_state(tap_get_end_state());
 291 }
 292
 293 static void armjtagew_path_move(int num_states, tap_state_t *path)
 294 {
 295         int i;
 296
 297         for (i = 0; i < num_states; i++) {
 298                 /*
 299                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 300                  * Either handle that here, or update the documentation with examples
 301                  * how to fix that in the configuration files.
 302                  */
 303                 if (path[i] == tap_state_transition(tap_get_state(), false))
 304                         armjtagew_tap_append_step(0, 0);
 305                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 306                         armjtagew_tap_append_step(1, 0);
 307                 else {
 308                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
 309                                 tap_state_name(tap_get_state()), tap_state_name(path[i]));
 310                         exit(-1);
 311                 }
 312
 313                 tap_set_state(path[i]);
 314         }
 315
 316         tap_set_end_state(tap_get_state());
 317 }
 318
 319 static void armjtagew_runtest(int num_cycles)
 320 {
 321         int i;
 322
 323         tap_state_t saved_end_state = tap_get_end_state();
 324
 325         /* only do a state_move when we're not already in IDLE */
 326         if (tap_get_state() != TAP_IDLE) {
 327                 armjtagew_end_state(TAP_IDLE);
 328                 armjtagew_state_move();
 329         }
 330
 331         /* execute num_cycles */
 332         for (i = 0; i < num_cycles; i++)
 333                 armjtagew_tap_append_step(0, 0);
 334
 335         /* finish in end_state */
 336         armjtagew_end_state(saved_end_state);
 337         if (tap_get_state() != tap_get_end_state())
 338                 armjtagew_state_move();
 339 }
 340
 341 static void armjtagew_scan(bool ir_scan,
 342         enum scan_type type,
 343         uint8_t *buffer,
 344         int scan_size,
 345         struct scan_command *command)
 346 {
 347         tap_state_t saved_end_state;
 348
 349         armjtagew_tap_ensure_space(1, scan_size + 8);
 350
 351         saved_end_state = tap_get_end_state();
 352
 353         /* Move to appropriate scan state */
 354         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 355
 356         /* Only move if we're not already there */
 357         if (tap_get_state() != tap_get_end_state())
 358                 armjtagew_state_move();
 359
 360         armjtagew_end_state(saved_end_state);
 361
 362         /* Scan */
 363         armjtagew_tap_append_scan(scan_size, buffer, command);
 364
 365         /* We are in Exit1, go to Pause */
 366         armjtagew_tap_append_step(0, 0);
 367
 368         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 369
 370         if (tap_get_state() != tap_get_end_state())
 371                 armjtagew_state_move();
 372 }
 373
 374 static void armjtagew_reset(int trst, int srst)
 375 {
 376         const uint8_t trst_mask = (1u << 5);
 377         const uint8_t srst_mask = (1u << 6);
 378         uint8_t val = 0;
 379         uint8_t outp_en = 0;
 380         uint8_t change_mask = 0;
 381         int result;
 382
 383         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 384
 385         if (srst == 0) {
 386                 val |= srst_mask;
 387                 outp_en &= ~srst_mask;          /* tristate */
 388                 change_mask |= srst_mask;
 389         } else if (srst == 1) {
 390                 val &= ~srst_mask;
 391                 outp_en |= srst_mask;
 392                 change_mask |= srst_mask;
 393         }
 394
 395         if (trst == 0) {
 396                 val |= trst_mask;
 397                 outp_en &= ~trst_mask;          /* tristate */
 398                 change_mask |= trst_mask;
 399         } else if (trst == 1) {
 400                 val &= ~trst_mask;
 401                 outp_en |= trst_mask;
 402                 change_mask |= trst_mask;
 403         }
 404
 405         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 406         usb_out_buffer[1] = val;
 407         usb_out_buffer[2] = outp_en;
 408         usb_out_buffer[3] = change_mask;
 409         result = armjtagew_usb_write(armjtagew_handle, 4);
 410         if (result != 4)
 411                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 412 }
 413
 414 static int armjtagew_get_status(void)
 415 {
 416         int result;
 417
 418         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 419         result = armjtagew_usb_message(armjtagew_handle, 1, 12);
 420
 421         if (result == 0) {
 422                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 423                 LOG_INFO(
 424                         "U_tg = %d mV, U_aux = %d mV, U_tgpwr = %d mV, I_tgpwr = %d mA, D1 = %d, Target power %s %s",
 425                         (int)(buf_get_u32(usb_in_buffer + 0, 0, 16)),
 426                         (int)(buf_get_u32(usb_in_buffer + 2, 0, 16)),
 427                         (int)(buf_get_u32(usb_in_buffer + 4, 0, 16)),
 428                         (int)(buf_get_u32(usb_in_buffer + 6, 0, 16)),
 429                         usb_in_buffer[9],
 430                         usb_in_buffer[11] ? "OVERCURRENT" : "OK",
 431                         usb_in_buffer[10] ? "enabled" : "disabled");
 432
 433                 if (u_tg < 1500)
 434                         LOG_ERROR("Vref too low. Check Target Power");
 435         } else
 436                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)", result);
 437
 438         return ERROR_OK;
 439 }
 440
 441 static int armjtagew_get_version_info(void)
 442 {
 443         int result;
 444         char sn[16];
 445         char auxinfo[257];
 446
 447         /* query hardware version */
 448         usb_out_buffer[0] = CMD_GET_VERSION;
 449         result = armjtagew_usb_message(armjtagew_handle, 1, 4 + 15 + 256);
 450
 451         if (result != 0) {
 452                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)", result);
 453                 return ERROR_JTAG_DEVICE_ERROR;
 454         }
 455
 456         memcpy(sn, usb_in_buffer + 4, 15);
 457         sn[15] = '\0';
 458         memcpy(auxinfo, usb_in_buffer + 4+15, 256);
 459         auxinfo[256] = '\0';
 460
 461         LOG_INFO(
 462                 "ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s", \
 463                 usb_in_buffer[1],
 464                 usb_in_buffer[0], \
 465                 isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X', \
 466                 sn,
 467                 auxinfo);
 468
 469         if (1 != usb_in_buffer[1] || 6 != usb_in_buffer[0])
 470                 LOG_WARNING(
 471                         "ARM-JTAG-EW firmware version %d.%d is untested with this version of OpenOCD. You might experience unexpected behavior.",
 472                         usb_in_buffer[1],
 473                         usb_in_buffer[0]);
 474         return ERROR_OK;
 475 }
 476
 477 COMMAND_HANDLER(armjtagew_handle_armjtagew_info_command)
 478 {
 479         if (armjtagew_get_version_info() == ERROR_OK) {
 480                 /* attempt to get status */
 481                 armjtagew_get_status();
 482         }
 483
 484         return ERROR_OK;
 485 }
 486
 487 static const struct command_registration armjtagew_command_handlers[] = {
 488         {
 489                 .name = "armjtagew_info",
 490                 .handler = &armjtagew_handle_armjtagew_info_command,
 491                 .mode = COMMAND_EXEC,
 492                 .help = "query armjtagew info",
 493                 .usage = "",
 494         },
 495         COMMAND_REGISTRATION_DONE
 496 };
 497
 498 struct jtag_interface armjtagew_interface = {
 499         .name = "arm-jtag-ew",
 500         .commands = armjtagew_command_handlers,
 501         .transports = jtag_only,
 502         .execute_queue = armjtagew_execute_queue,
 503         .speed = armjtagew_speed,
 504         .speed_div = armjtagew_speed_div,
 505         .khz = armjtagew_khz,
 506         .init = armjtagew_init,
 507         .quit = armjtagew_quit,
 508 };
 509
 510 /**************************************************************************
 511  * ARM-JTAG-EW tap functions */
 512
 513 /* 2048 is the max value we can use here */
 514 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 515
 516 static int tap_length;
 517 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 518 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 519 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 520
 521 struct pending_scan_result {
 522         int first;      /* First bit position in tdo_buffer to read */
 523         int length;     /* Number of bits to read */
 524         struct scan_command *command;   /* Corresponding scan command */
 525         uint8_t *buffer;
 526 };
 527
 528 #define MAX_PENDING_SCAN_RESULTS 256
 529
 530 static int pending_scan_results_length;
 531 static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 532
 533 static int last_tms;
 534
 535 static void armjtagew_tap_init(void)
 536 {
 537         tap_length = 0;
 538         pending_scan_results_length = 0;
 539 }
 540
 541 static void armjtagew_tap_ensure_space(int scans, int bits)
 542 {
 543         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 544         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 545
 546         if (scans > available_scans || bits > available_bits)
 547                 armjtagew_tap_execute();
 548 }
 549
 550 static void armjtagew_tap_append_step(int tms, int tdi)
 551 {
 552         last_tms = tms;
 553         int index_local = tap_length / 8;
 554
 555         if (index_local < ARMJTAGEW_TAP_BUFFER_SIZE) {
 556                 int bit_index = tap_length % 8;
 557                 uint8_t bit = 1 << bit_index;
 558
 559                 if (tms)
 560                         tms_buffer[index_local] |= bit;
 561                 else
 562                         tms_buffer[index_local] &= ~bit;
 563
 564                 if (tdi)
 565                         tdi_buffer[index_local] |= bit;
 566                 else
 567                         tdi_buffer[index_local] &= ~bit;
 568
 569                 tap_length++;
 570         } else
 571                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 572 }
 573
 574 void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command)
 575 {
 576         struct pending_scan_result *pending_scan_result =
 577                 &pending_scan_results_buffer[pending_scan_results_length];
 578         int i;
 579
 580         pending_scan_result->first = tap_length;
 581         pending_scan_result->length = length;
 582         pending_scan_result->command = command;
 583         pending_scan_result->buffer = buffer;
 584
 585         for (i = 0; i < length; i++)
 586                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 587         pending_scan_results_length++;
 588 }
 589
 590 /* Pad and send a tap sequence to the device, and receive the answer.
 591  * For the purpose of padding we assume that we are in idle or pause state. */
 592 static int armjtagew_tap_execute(void)
 593 {
 594         int byte_length;
 595         int tms_offset;
 596         int tdi_offset;
 597         int i;
 598         int result;
 599
 600         if (tap_length > 0) {
 601                 /* Pad last byte so that tap_length is divisible by 8 */
 602                 while (tap_length % 8 != 0) {
 603                         /* More of the last TMS value keeps us in the same state,
 604                          * analogous to free-running JTAG interfaces. */
 605                         armjtagew_tap_append_step(last_tms, 0);
 606                 }
 607
 608                 byte_length = tap_length / 8;
 609
 610                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 611                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 612
 613                 tms_offset = 3;
 614                 for (i = 0; i < byte_length; i++)
 615                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i], 8);
 616
 617                 tdi_offset = tms_offset + byte_length;
 618                 for (i = 0; i < byte_length; i++)
 619                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i], 8);
 620
 621                 result = armjtagew_usb_message(armjtagew_handle,
 622                                 3 + 2 * byte_length,
 623                                 byte_length + 4);
 624
 625                 if (result == 0) {
 626                         int stat_local;
 627
 628                         stat_local = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 629                         if (stat_local) {
 630                                 LOG_ERROR(
 631                                         "armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command",
 632                                         stat_local);
 633                                 return ERROR_JTAG_QUEUE_FAILED;
 634                         }
 635
 636                         for (i = 0; i < byte_length; i++)
 637                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i], 8);
 638
 639                         for (i = 0; i < pending_scan_results_length; i++) {
 640                                 struct pending_scan_result *pending_scan_result =
 641                                         &pending_scan_results_buffer[i];
 642                                 uint8_t *buffer = pending_scan_result->buffer;
 643                                 int length = pending_scan_result->length;
 644                                 int first = pending_scan_result->first;
 645                                 struct scan_command *command = pending_scan_result->command;
 646
 647                                 /* Copy to buffer */
 648                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 649
 650                                 LOG_DEBUG_IO("pending scan result, length = %d", length);
 651
 652 #ifdef _DEBUG_USB_COMMS_
 653                                 armjtagew_debug_buffer(buffer, byte_length);
 654 #endif
 655
 656                                 if (jtag_read_buffer(buffer, command) != ERROR_OK) {
 657                                         armjtagew_tap_init();
 658                                         return ERROR_JTAG_QUEUE_FAILED;
 659                                 }
 660
 661                                 if (pending_scan_result->buffer != NULL)
 662                                         free(pending_scan_result->buffer);
 663                         }
 664                 } else {
 665                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d",
 666                                 result,
 667                                 byte_length);
 668                         return ERROR_JTAG_QUEUE_FAILED;
 669                 }
 670
 671                 armjtagew_tap_init();
 672         }
 673
 674         return ERROR_OK;
 675 }
 676
 677 /****************************************************************************
 678  * JLink USB low-level functions */
 679
 680 static struct armjtagew *armjtagew_usb_open()
 681 {
 682         usb_init();
 683
 684         const uint16_t vids[] = { USB_VID, 0 };
 685         const uint16_t pids[] = { USB_PID, 0 };
 686         struct usb_dev_handle *dev;
 687         if (jtag_usb_open(vids, pids, &dev) != ERROR_OK)
 688                 return NULL;
 689
 690         struct armjtagew *result = malloc(sizeof(struct armjtagew));
 691         result->usb_handle = dev;
 692
 693 #if 0
 694         /* usb_set_configuration required under win32 */
 695         usb_set_configuration(dev, dev->config[0].bConfigurationValue);
 696 #endif
 697         usb_claim_interface(dev, 0);
 698 #if 0
 699         /*
 700          * This makes problems under Mac OS X. And is not needed
 701          * under Windows. Hopefully this will not break a linux build
 702          */
 703         usb_set_altinterface(dev, 0);
 704 #endif
 705         return result;
 706 }
 707
 708 static void armjtagew_usb_close(struct armjtagew *armjtagew)
 709 {
 710         usb_close(armjtagew->usb_handle);
 711         free(armjtagew);
 712 }
 713
 714 /* Send a message and receive the reply. */
 715 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length)
 716 {
 717         int result;
 718
 719         result = armjtagew_usb_write(armjtagew, out_length);
 720         if (result == out_length) {
 721                 result = armjtagew_usb_read(armjtagew, in_length);
 722                 if (result != in_length) {
 723                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)",
 724                                 in_length,
 725                                 result);
 726                         return -1;
 727                 }
 728         } else {
 729                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 730                 return -1;
 731         }
 732         return 0;
 733 }
 734
 735 /* Write data from out_buffer to USB. */
 736 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length)
 737 {
 738         int result;
 739
 740         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE) {
 741                 LOG_ERROR("armjtagew_write illegal out_length=%d (max=%d)",
 742                         out_length,
 743                         ARMJTAGEW_OUT_BUFFER_SIZE);
 744                 return -1;
 745         }
 746
 747         result = usb_bulk_write(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_OUT, \
 748                         (char *)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT);
 749
 750         LOG_DEBUG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 751
 752 #ifdef _DEBUG_USB_COMMS_
 753         armjtagew_debug_buffer(usb_out_buffer, out_length);
 754 #endif
 755         return result;
 756 }
 757
 758 /* Read data from USB into in_buffer. */
 759 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length)
 760 {
 761         int result = usb_bulk_read(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_IN, \
 762                         (char *)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT);
 763
 764         LOG_DEBUG_IO("armjtagew_usb_read, result = %d", result);
 765
 766 #ifdef _DEBUG_USB_COMMS_
 767         armjtagew_debug_buffer(usb_in_buffer, result);
 768 #endif
 769         return result;
 770 }
 771
 772 #ifdef _DEBUG_USB_COMMS_
 773 #define BYTES_PER_LINE  16
 774
 775 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 776 {
 777         char line[81];
 778         char s[4];
 779         int i;
 780         int j;
 781
 782         for (i = 0; i < length; i += BYTES_PER_LINE) {
 783                 snprintf(line, 5, "%04x", i);
 784                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++) {
 785                         snprintf(s, 4, " %02x", buffer[j]);
 786                         strcat(line, s);
 787                 }
 788                 LOG_DEBUG("%s", line);
 789
 790                 /* Prevent GDB timeout (writing to log might take some time) */
 791                 keep_alive();
 792         }
 793 }
 794 #endif