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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 "libusb_helper.h"
  26
  27 #define USB_VID                                         0x15ba
  28 #define USB_PID                                         0x001e
  29
  30 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  31 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  32
  33 #define ARMJTAGEW_USB_TIMEOUT           2000
  34
  35 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  36 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  37
  38 /* USB command request codes. */
  39 #define CMD_GET_VERSION                         0x00
  40 #define CMD_SELECT_DPIMPL                       0x10
  41 #define CMD_SET_TCK_FREQUENCY           0x11
  42 #define CMD_GET_TCK_FREQUENCY           0x12
  43 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  44 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  45 #define CMD_TAP_SHIFT                           0x17
  46 #define CMD_SET_TAPHW_STATE                     0x20
  47 #define CMD_GET_TAPHW_STATE                     0x21
  48 #define CMD_TGPWR_SETUP                         0x22
  49
  50 /* Global USB buffers */
  51 static uint8_t usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  52 static uint8_t usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  53
  54 /* Queue command functions */
  55 static void armjtagew_end_state(tap_state_t state);
  56 static void armjtagew_state_move(void);
  57 static void armjtagew_path_move(int num_states, tap_state_t *path);
  58 static void armjtagew_runtest(int num_cycles);
  59 static void armjtagew_scan(bool ir_scan,
  60                 enum scan_type type,
  61                 uint8_t *buffer,
  62                 int scan_size,
  63                 struct scan_command *command);
  64 static void armjtagew_reset(int trst, int srst);
  65 /* static void armjtagew_simple_command(uint8_t command); */
  66 static int armjtagew_get_status(void);
  67
  68 /* tap buffer functions */
  69 static void armjtagew_tap_init(void);
  70 static int armjtagew_tap_execute(void);
  71 static void armjtagew_tap_ensure_space(int scans, int bits);
  72 static void armjtagew_tap_append_step(int tms, int tdi);
  73 static void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command);
  74
  75 /* ARM-JTAG-EW lowlevel functions */
  76 struct armjtagew {
  77         struct libusb_device_handle *usb_handle;
  78 };
  79
  80 static struct armjtagew *armjtagew_usb_open(void);
  81 static void armjtagew_usb_close(struct armjtagew *armjtagew);
  82 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length);
  83 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length);
  84 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length);
  85
  86 /* helper functions */
  87 static int armjtagew_get_version_info(void);
  88
  89 #ifdef _DEBUG_USB_COMMS_
  90 static void armjtagew_debug_buffer(uint8_t *buffer, int length);
  91 #endif
  92
  93 static struct armjtagew *armjtagew_handle;
  94
  95 /**************************************************************************
  96  * External interface implementation */
  97
  98 static int armjtagew_execute_queue(void)
  99 {
 100         struct jtag_command *cmd = jtag_command_queue;
 101         int scan_size;
 102         enum scan_type type;
 103         uint8_t *buffer;
 104
 105         while (cmd != NULL) {
 106                 switch (cmd->type) {
 107                         case JTAG_RUNTEST:
 108                                 LOG_DEBUG_IO("runtest %i cycles, end in %i",
 109                                                 cmd->cmd.runtest->num_cycles,
 110                                                 cmd->cmd.runtest->end_state);
 111
 112                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 113                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 114                                 break;
 115
 116                         case JTAG_TLR_RESET:
 117                                 LOG_DEBUG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 118
 119                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 120                                 armjtagew_state_move();
 121                                 break;
 122
 123                         case JTAG_PATHMOVE:
 124                                 LOG_DEBUG_IO("pathmove: %i states, end in %i",
 125                                                 cmd->cmd.pathmove->num_states,
 126                                                 cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 127
 128                                 armjtagew_path_move(cmd->cmd.pathmove->num_states,
 129                                                 cmd->cmd.pathmove->path);
 130                                 break;
 131
 132                         case JTAG_SCAN:
 133                                 LOG_DEBUG_IO("scan end in %i", cmd->cmd.scan->end_state);
 134
 135                                 armjtagew_end_state(cmd->cmd.scan->end_state);
 136
 137                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 138                                 LOG_DEBUG_IO("scan input, length = %d", scan_size);
 139
 140 #ifdef _DEBUG_USB_COMMS_
 141                                 armjtagew_debug_buffer(buffer, (scan_size + 7) / 8);
 142 #endif
 143                                 type = jtag_scan_type(cmd->cmd.scan);
 144                                 armjtagew_scan(cmd->cmd.scan->ir_scan,
 145                                                 type, buffer,
 146                                                 scan_size, cmd->cmd.scan);
 147                                 break;
 148
 149                         case JTAG_RESET:
 150                                 LOG_DEBUG_IO("reset trst: %i srst %i",
 151                                                 cmd->cmd.reset->trst,
 152                                                 cmd->cmd.reset->srst);
 153
 154                                 armjtagew_tap_execute();
 155
 156                                 if (cmd->cmd.reset->trst == 1)
 157                                         tap_set_state(TAP_RESET);
 158                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 159                                 break;
 160
 161                         case JTAG_SLEEP:
 162                                 LOG_DEBUG_IO("sleep %" PRIu32, cmd->cmd.sleep->us);
 163                                 armjtagew_tap_execute();
 164                                 jtag_sleep(cmd->cmd.sleep->us);
 165                                 break;
 166
 167                         default:
 168                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 169                                 exit(-1);
 170                 }
 171                 cmd = cmd->next;
 172         }
 173
 174         return armjtagew_tap_execute();
 175 }
 176
 177 /* Sets speed in kHz. */
 178 static int armjtagew_speed(int speed)
 179 {
 180         int result;
 181         int speed_real;
 182
 183
 184         usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 185         buf_set_u32(usb_out_buffer + 1, 0, 32, speed*1000);
 186
 187         result = armjtagew_usb_message(armjtagew_handle, 5, 4);
 188
 189         if (result < 0) {
 190                 LOG_ERROR("ARM-JTAG-EW setting speed failed (%d)", result);
 191                 return ERROR_JTAG_DEVICE_ERROR;
 192         }
 193
 194         usb_out_buffer[0] = CMD_GET_TCK_FREQUENCY;
 195         result = armjtagew_usb_message(armjtagew_handle, 1, 4);
 196         speed_real = (int)buf_get_u32(usb_in_buffer, 0, 32) / 1000;
 197         if (result < 0) {
 198                 LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 199                 return ERROR_JTAG_DEVICE_ERROR;
 200         } else
 201                 LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 202
 203         return ERROR_OK;
 204 }
 205
 206 static int armjtagew_khz(int khz, int *jtag_speed)
 207 {
 208         *jtag_speed = khz;
 209
 210         return ERROR_OK;
 211 }
 212
 213 static int armjtagew_speed_div(int speed, int *khz)
 214 {
 215         *khz = speed;
 216
 217         return ERROR_OK;
 218 }
 219
 220 static int armjtagew_init(void)
 221 {
 222         int check_cnt;
 223
 224         armjtagew_handle = armjtagew_usb_open();
 225
 226         if (armjtagew_handle == 0) {
 227                 LOG_ERROR(
 228                         "Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 229                 return ERROR_JTAG_INIT_FAILED;
 230         }
 231
 232         check_cnt = 0;
 233         while (check_cnt < 3) {
 234                 if (armjtagew_get_version_info() == ERROR_OK) {
 235                         /* attempt to get status */
 236                         armjtagew_get_status();
 237                         break;
 238                 }
 239
 240                 check_cnt++;
 241         }
 242
 243         if (check_cnt == 3)
 244                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 245
 246         /* Initial JTAG speed (for reset and initialization): 32 kHz */
 247         armjtagew_speed(32);
 248
 249         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 250
 251         armjtagew_reset(0, 0);
 252         armjtagew_tap_init();
 253
 254         return ERROR_OK;
 255 }
 256
 257 static int armjtagew_quit(void)
 258 {
 259         armjtagew_usb_close(armjtagew_handle);
 260         return ERROR_OK;
 261 }
 262
 263 /**************************************************************************
 264  * Queue command implementations */
 265
 266 static void armjtagew_end_state(tap_state_t state)
 267 {
 268         if (tap_is_state_stable(state))
 269                 tap_set_end_state(state);
 270         else {
 271                 LOG_ERROR("BUG: %i is not a valid end state", state);
 272                 exit(-1);
 273         }
 274 }
 275
 276 /* Goes to the end state. */
 277 static void armjtagew_state_move(void)
 278 {
 279         int i;
 280         int tms = 0;
 281         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 282         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 283
 284         for (i = 0; i < tms_count; i++) {
 285                 tms = (tms_scan >> i) & 1;
 286                 armjtagew_tap_append_step(tms, 0);
 287         }
 288
 289         tap_set_state(tap_get_end_state());
 290 }
 291
 292 static void armjtagew_path_move(int num_states, tap_state_t *path)
 293 {
 294         int i;
 295
 296         for (i = 0; i < num_states; i++) {
 297                 /*
 298                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 299                  * Either handle that here, or update the documentation with examples
 300                  * how to fix that in the configuration files.
 301                  */
 302                 if (path[i] == tap_state_transition(tap_get_state(), false))
 303                         armjtagew_tap_append_step(0, 0);
 304                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 305                         armjtagew_tap_append_step(1, 0);
 306                 else {
 307                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
 308                                 tap_state_name(tap_get_state()), tap_state_name(path[i]));
 309                         exit(-1);
 310                 }
 311
 312                 tap_set_state(path[i]);
 313         }
 314
 315         tap_set_end_state(tap_get_state());
 316 }
 317
 318 static void armjtagew_runtest(int num_cycles)
 319 {
 320         int i;
 321
 322         tap_state_t saved_end_state = tap_get_end_state();
 323
 324         /* only do a state_move when we're not already in IDLE */
 325         if (tap_get_state() != TAP_IDLE) {
 326                 armjtagew_end_state(TAP_IDLE);
 327                 armjtagew_state_move();
 328         }
 329
 330         /* execute num_cycles */
 331         for (i = 0; i < num_cycles; i++)
 332                 armjtagew_tap_append_step(0, 0);
 333
 334         /* finish in end_state */
 335         armjtagew_end_state(saved_end_state);
 336         if (tap_get_state() != tap_get_end_state())
 337                 armjtagew_state_move();
 338 }
 339
 340 static void armjtagew_scan(bool ir_scan,
 341         enum scan_type type,
 342         uint8_t *buffer,
 343         int scan_size,
 344         struct scan_command *command)
 345 {
 346         tap_state_t saved_end_state;
 347
 348         armjtagew_tap_ensure_space(1, scan_size + 8);
 349
 350         saved_end_state = tap_get_end_state();
 351
 352         /* Move to appropriate scan state */
 353         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 354
 355         /* Only move if we're not already there */
 356         if (tap_get_state() != tap_get_end_state())
 357                 armjtagew_state_move();
 358
 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                 .usage = "",
 493         },
 494         COMMAND_REGISTRATION_DONE
 495 };
 496
 497 static struct jtag_interface armjtagew_interface = {
 498         .execute_queue = armjtagew_execute_queue,
 499 };
 500
 501 struct adapter_driver armjtagew_adapter_driver = {
 502         .name = "arm-jtag-ew",
 503         .transports = jtag_only,
 504         .commands = armjtagew_command_handlers,
 505
 506         .init = armjtagew_init,
 507         .quit = armjtagew_quit,
 508         .speed = armjtagew_speed,
 509         .khz = armjtagew_khz,
 510         .speed_div = armjtagew_speed_div,
 511
 512         .jtag_ops = &armjtagew_interface,
 513 };
 514
 515 /**************************************************************************
 516  * ARM-JTAG-EW tap functions */
 517
 518 /* 2048 is the max value we can use here */
 519 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 520
 521 static int tap_length;
 522 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 523 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 524 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 525
 526 struct pending_scan_result {
 527         int first;      /* First bit position in tdo_buffer to read */
 528         int length;     /* Number of bits to read */
 529         struct scan_command *command;   /* Corresponding scan command */
 530         uint8_t *buffer;
 531 };
 532
 533 #define MAX_PENDING_SCAN_RESULTS 256
 534
 535 static int pending_scan_results_length;
 536 static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 537
 538 static int last_tms;
 539
 540 static void armjtagew_tap_init(void)
 541 {
 542         tap_length = 0;
 543         pending_scan_results_length = 0;
 544 }
 545
 546 static void armjtagew_tap_ensure_space(int scans, int bits)
 547 {
 548         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 549         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 550
 551         if (scans > available_scans || bits > available_bits)
 552                 armjtagew_tap_execute();
 553 }
 554
 555 static void armjtagew_tap_append_step(int tms, int tdi)
 556 {
 557         last_tms = tms;
 558         int index_local = tap_length / 8;
 559
 560         if (index_local < ARMJTAGEW_TAP_BUFFER_SIZE) {
 561                 int bit_index = tap_length % 8;
 562                 uint8_t bit = 1 << bit_index;
 563
 564                 if (tms)
 565                         tms_buffer[index_local] |= bit;
 566                 else
 567                         tms_buffer[index_local] &= ~bit;
 568
 569                 if (tdi)
 570                         tdi_buffer[index_local] |= bit;
 571                 else
 572                         tdi_buffer[index_local] &= ~bit;
 573
 574                 tap_length++;
 575         } else
 576                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 577 }
 578
 579 void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command)
 580 {
 581         struct pending_scan_result *pending_scan_result =
 582                 &pending_scan_results_buffer[pending_scan_results_length];
 583         int i;
 584
 585         pending_scan_result->first = tap_length;
 586         pending_scan_result->length = length;
 587         pending_scan_result->command = command;
 588         pending_scan_result->buffer = buffer;
 589
 590         for (i = 0; i < length; i++)
 591                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 592         pending_scan_results_length++;
 593 }
 594
 595 /* Pad and send a tap sequence to the device, and receive the answer.
 596  * For the purpose of padding we assume that we are in idle or pause state. */
 597 static int armjtagew_tap_execute(void)
 598 {
 599         int byte_length;
 600         int tms_offset;
 601         int tdi_offset;
 602         int i;
 603         int result;
 604
 605         if (tap_length > 0) {
 606                 /* Pad last byte so that tap_length is divisible by 8 */
 607                 while (tap_length % 8 != 0) {
 608                         /* More of the last TMS value keeps us in the same state,
 609                          * analogous to free-running JTAG interfaces. */
 610                         armjtagew_tap_append_step(last_tms, 0);
 611                 }
 612
 613                 byte_length = tap_length / 8;
 614
 615                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 616                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 617
 618                 tms_offset = 3;
 619                 for (i = 0; i < byte_length; i++)
 620                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i], 8);
 621
 622                 tdi_offset = tms_offset + byte_length;
 623                 for (i = 0; i < byte_length; i++)
 624                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i], 8);
 625
 626                 result = armjtagew_usb_message(armjtagew_handle,
 627                                 3 + 2 * byte_length,
 628                                 byte_length + 4);
 629
 630                 if (result == 0) {
 631                         int stat_local;
 632
 633                         stat_local = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 634                         if (stat_local) {
 635                                 LOG_ERROR(
 636                                         "armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command",
 637                                         stat_local);
 638                                 return ERROR_JTAG_QUEUE_FAILED;
 639                         }
 640
 641                         for (i = 0; i < byte_length; i++)
 642                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i], 8);
 643
 644                         for (i = 0; i < pending_scan_results_length; i++) {
 645                                 struct pending_scan_result *pending_scan_result =
 646                                         &pending_scan_results_buffer[i];
 647                                 uint8_t *buffer = pending_scan_result->buffer;
 648                                 int length = pending_scan_result->length;
 649                                 int first = pending_scan_result->first;
 650                                 struct scan_command *command = pending_scan_result->command;
 651
 652                                 /* Copy to buffer */
 653                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 654
 655                                 LOG_DEBUG_IO("pending scan result, length = %d", length);
 656
 657 #ifdef _DEBUG_USB_COMMS_
 658                                 armjtagew_debug_buffer(buffer, byte_length);
 659 #endif
 660
 661                                 if (jtag_read_buffer(buffer, command) != ERROR_OK) {
 662                                         armjtagew_tap_init();
 663                                         return ERROR_JTAG_QUEUE_FAILED;
 664                                 }
 665
 666                                 free(pending_scan_result->buffer);
 667                         }
 668                 } else {
 669                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d",
 670                                 result,
 671                                 byte_length);
 672                         return ERROR_JTAG_QUEUE_FAILED;
 673                 }
 674
 675                 armjtagew_tap_init();
 676         }
 677
 678         return ERROR_OK;
 679 }
 680
 681 /****************************************************************************
 682  * JLink USB low-level functions */
 683
 684 static struct armjtagew *armjtagew_usb_open(void)
 685 {
 686         const uint16_t vids[] = { USB_VID, 0 };
 687         const uint16_t pids[] = { USB_PID, 0 };
 688         struct libusb_device_handle *dev;
 689
 690         if (jtag_libusb_open(vids, pids, NULL, &dev, NULL) != ERROR_OK)
 691                 return NULL;
 692
 693         struct armjtagew *result = malloc(sizeof(struct armjtagew));
 694         result->usb_handle = dev;
 695
 696 #if 0
 697         /* libusb_set_configuration required under win32 */
 698         struct libusb_config_descriptor *config;
 699         struct libusb_device *usb_dev = libusb_get_device(dev);
 700         libusb_get_config_descriptor(usb_dev, 0, &config);
 701         libusb_set_configuration(dev, config->bConfigurationValue);
 702 #endif
 703         libusb_claim_interface(dev, 0);
 704 #if 0
 705         /*
 706          * This makes problems under Mac OS X. And is not needed
 707          * under Windows. Hopefully this will not break a linux build
 708          */
 709         libusb_set_interface_alt_setting(dev, 0, 0);
 710 #endif
 711         return result;
 712 }
 713
 714 static void armjtagew_usb_close(struct armjtagew *armjtagew)
 715 {
 716         libusb_close(armjtagew->usb_handle);
 717         free(armjtagew);
 718 }
 719
 720 /* Send a message and receive the reply. */
 721 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length)
 722 {
 723         int result;
 724
 725         result = armjtagew_usb_write(armjtagew, out_length);
 726         if (result == out_length) {
 727                 result = armjtagew_usb_read(armjtagew, in_length);
 728                 if (result != in_length) {
 729                         LOG_ERROR("jtag_libusb_bulk_read failed (requested=%d, result=%d)",
 730                                 in_length,
 731                                 result);
 732                         return -1;
 733                 }
 734         } else {
 735                 LOG_ERROR("jtag_libusb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 736                 return -1;
 737         }
 738         return 0;
 739 }
 740
 741 /* Write data from out_buffer to USB. */
 742 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length)
 743 {
 744         int result;
 745         int transferred;
 746
 747         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE) {
 748                 LOG_ERROR("armjtagew_write illegal out_length=%d (max=%d)",
 749                         out_length,
 750                         ARMJTAGEW_OUT_BUFFER_SIZE);
 751                 return -1;
 752         }
 753
 754         result = jtag_libusb_bulk_write(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_OUT,
 755                         (char *)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT, &transferred);
 756
 757         LOG_DEBUG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 758
 759 #ifdef _DEBUG_USB_COMMS_
 760         armjtagew_debug_buffer(usb_out_buffer, out_length);
 761 #endif
 762         if (result != ERROR_OK)
 763                 return -1;
 764         return transferred;
 765 }
 766
 767 /* Read data from USB into in_buffer. */
 768 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length)
 769 {
 770         int transferred;
 771         int result = jtag_libusb_bulk_read(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_IN,
 772                         (char *)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT, &transferred);
 773
 774         LOG_DEBUG_IO("armjtagew_usb_read, result = %d", result);
 775
 776 #ifdef _DEBUG_USB_COMMS_
 777         armjtagew_debug_buffer(usb_in_buffer, result);
 778 #endif
 779         if (result != ERROR_OK)
 780                 return -1;
 781         return transferred;
 782 }
 783
 784 #ifdef _DEBUG_USB_COMMS_
 785 #define BYTES_PER_LINE  16
 786
 787 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 788 {
 789         char line[81];
 790         char s[4];
 791         int i;
 792         int j;
 793
 794         for (i = 0; i < length; i += BYTES_PER_LINE) {
 795                 snprintf(line, 5, "%04x", i);
 796                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++) {
 797                         snprintf(s, 4, " %02x", buffer[j]);
 798                         strcat(line, s);
 799                 }
 800                 LOG_DEBUG("%s", line);
 801
 802                 /* Prevent GDB timeout (writing to log might take some time) */
 803                 keep_alive();
 804         }
 805 }
 806 #endif