git.gag.com Git - fw/openocd/blob - src/jtag/drivers/arm-jtag-ew.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2009 by Dimitar Dimitrov <dinuxbg@gmail.com>            *
   5  *   based on Dominic Rath's and Benedikt Sauter's usbprog.c               *
   6  ***************************************************************************/
   7
   8 #ifdef HAVE_CONFIG_H
   9 #include "config.h"
  10 #endif
  11
  12 #include <jtag/interface.h>
  13 #include <jtag/commands.h>
  14 #include "helper/system.h"
  15 #include "libusb_helper.h"
  16
  17 #define USB_VID                                         0x15ba
  18 #define USB_PID                                         0x001e
  19
  20 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  21 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  22
  23 #define ARMJTAGEW_USB_TIMEOUT           2000
  24
  25 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  26 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  27
  28 /* USB command request codes. */
  29 #define CMD_GET_VERSION                         0x00
  30 #define CMD_SELECT_DPIMPL                       0x10
  31 #define CMD_SET_TCK_FREQUENCY           0x11
  32 #define CMD_GET_TCK_FREQUENCY           0x12
  33 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  34 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  35 #define CMD_TAP_SHIFT                           0x17
  36 #define CMD_SET_TAPHW_STATE                     0x20
  37 #define CMD_GET_TAPHW_STATE                     0x21
  38 #define CMD_TGPWR_SETUP                         0x22
  39
  40 /* Global USB buffers */
  41 static uint8_t usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  42 static uint8_t usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  43
  44 /* Queue command functions */
  45 static void armjtagew_end_state(tap_state_t state);
  46 static void armjtagew_state_move(void);
  47 static void armjtagew_path_move(int num_states, tap_state_t *path);
  48 static void armjtagew_runtest(int num_cycles);
  49 static void armjtagew_scan(bool ir_scan,
  50                 enum scan_type type,
  51                 uint8_t *buffer,
  52                 int scan_size,
  53                 struct scan_command *command);
  54 static void armjtagew_reset(int trst, int srst);
  55 /* static void armjtagew_simple_command(uint8_t command); */
  56 static int armjtagew_get_status(void);
  57
  58 /* tap buffer functions */
  59 static void armjtagew_tap_init(void);
  60 static int armjtagew_tap_execute(void);
  61 static void armjtagew_tap_ensure_space(int scans, int bits);
  62 static void armjtagew_tap_append_step(int tms, int tdi);
  63 static void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command);
  64
  65 /* ARM-JTAG-EW lowlevel functions */
  66 struct armjtagew {
  67         struct libusb_device_handle *usb_handle;
  68 };
  69
  70 static struct armjtagew *armjtagew_usb_open(void);
  71 static void armjtagew_usb_close(struct armjtagew *armjtagew);
  72 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length);
  73 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length);
  74 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length);
  75
  76 /* helper functions */
  77 static int armjtagew_get_version_info(void);
  78
  79 #ifdef _DEBUG_USB_COMMS_
  80 static void armjtagew_debug_buffer(uint8_t *buffer, int length);
  81 #endif
  82
  83 static struct armjtagew *armjtagew_handle;
  84
  85 /**************************************************************************
  86  * External interface implementation */
  87
  88 static int armjtagew_execute_queue(void)
  89 {
  90         struct jtag_command *cmd = jtag_command_queue;
  91         int scan_size;
  92         enum scan_type type;
  93         uint8_t *buffer;
  94
  95         while (cmd) {
  96                 switch (cmd->type) {
  97                         case JTAG_RUNTEST:
  98                                 LOG_DEBUG_IO("runtest %i cycles, end in %i",
  99                                                 cmd->cmd.runtest->num_cycles,
 100                                                 cmd->cmd.runtest->end_state);
 101
 102                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 103                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 104                                 break;
 105
 106                         case JTAG_TLR_RESET:
 107                                 LOG_DEBUG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 108
 109                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 110                                 armjtagew_state_move();
 111                                 break;
 112
 113                         case JTAG_PATHMOVE:
 114                                 LOG_DEBUG_IO("pathmove: %i states, end in %i",
 115                                                 cmd->cmd.pathmove->num_states,
 116                                                 cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 117
 118                                 armjtagew_path_move(cmd->cmd.pathmove->num_states,
 119                                                 cmd->cmd.pathmove->path);
 120                                 break;
 121
 122                         case JTAG_SCAN:
 123                                 LOG_DEBUG_IO("scan end in %i", cmd->cmd.scan->end_state);
 124
 125                                 armjtagew_end_state(cmd->cmd.scan->end_state);
 126
 127                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 128                                 LOG_DEBUG_IO("scan input, length = %d", scan_size);
 129
 130 #ifdef _DEBUG_USB_COMMS_
 131                                 armjtagew_debug_buffer(buffer, (scan_size + 7) / 8);
 132 #endif
 133                                 type = jtag_scan_type(cmd->cmd.scan);
 134                                 armjtagew_scan(cmd->cmd.scan->ir_scan,
 135                                                 type, buffer,
 136                                                 scan_size, cmd->cmd.scan);
 137                                 break;
 138
 139                         case JTAG_RESET:
 140                                 LOG_DEBUG_IO("reset trst: %i srst %i",
 141                                                 cmd->cmd.reset->trst,
 142                                                 cmd->cmd.reset->srst);
 143
 144                                 armjtagew_tap_execute();
 145
 146                                 if (cmd->cmd.reset->trst == 1)
 147                                         tap_set_state(TAP_RESET);
 148                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 149                                 break;
 150
 151                         case JTAG_SLEEP:
 152                                 LOG_DEBUG_IO("sleep %" PRIu32, cmd->cmd.sleep->us);
 153                                 armjtagew_tap_execute();
 154                                 jtag_sleep(cmd->cmd.sleep->us);
 155                                 break;
 156
 157                         default:
 158                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 159                                 exit(-1);
 160                 }
 161                 cmd = cmd->next;
 162         }
 163
 164         return armjtagew_tap_execute();
 165 }
 166
 167 /* Sets speed in kHz. */
 168 static int armjtagew_speed(int speed)
 169 {
 170         int result;
 171         int speed_real;
 172
 173
 174         usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 175         buf_set_u32(usb_out_buffer + 1, 0, 32, speed*1000);
 176
 177         result = armjtagew_usb_message(armjtagew_handle, 5, 4);
 178
 179         if (result < 0) {
 180                 LOG_ERROR("ARM-JTAG-EW setting speed failed (%d)", result);
 181                 return ERROR_JTAG_DEVICE_ERROR;
 182         }
 183
 184         usb_out_buffer[0] = CMD_GET_TCK_FREQUENCY;
 185         result = armjtagew_usb_message(armjtagew_handle, 1, 4);
 186         speed_real = (int)buf_get_u32(usb_in_buffer, 0, 32) / 1000;
 187         if (result < 0) {
 188                 LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 189                 return ERROR_JTAG_DEVICE_ERROR;
 190         } else
 191                 LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 192
 193         return ERROR_OK;
 194 }
 195
 196 static int armjtagew_khz(int khz, int *jtag_speed)
 197 {
 198         *jtag_speed = khz;
 199
 200         return ERROR_OK;
 201 }
 202
 203 static int armjtagew_speed_div(int speed, int *khz)
 204 {
 205         *khz = speed;
 206
 207         return ERROR_OK;
 208 }
 209
 210 static int armjtagew_init(void)
 211 {
 212         int check_cnt;
 213
 214         armjtagew_handle = armjtagew_usb_open();
 215
 216         if (armjtagew_handle == 0) {
 217                 LOG_ERROR(
 218                         "Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 219                 return ERROR_JTAG_INIT_FAILED;
 220         }
 221
 222         check_cnt = 0;
 223         while (check_cnt < 3) {
 224                 if (armjtagew_get_version_info() == ERROR_OK) {
 225                         /* attempt to get status */
 226                         armjtagew_get_status();
 227                         break;
 228                 }
 229
 230                 check_cnt++;
 231         }
 232
 233         if (check_cnt == 3)
 234                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 235
 236         /* Initial JTAG speed (for reset and initialization): 32 kHz */
 237         armjtagew_speed(32);
 238
 239         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 240
 241         armjtagew_reset(0, 0);
 242         armjtagew_tap_init();
 243
 244         return ERROR_OK;
 245 }
 246
 247 static int armjtagew_quit(void)
 248 {
 249         armjtagew_usb_close(armjtagew_handle);
 250         return ERROR_OK;
 251 }
 252
 253 /**************************************************************************
 254  * Queue command implementations */
 255
 256 static void armjtagew_end_state(tap_state_t state)
 257 {
 258         if (tap_is_state_stable(state))
 259                 tap_set_end_state(state);
 260         else {
 261                 LOG_ERROR("BUG: %i is not a valid end state", state);
 262                 exit(-1);
 263         }
 264 }
 265
 266 /* Goes to the end state. */
 267 static void armjtagew_state_move(void)
 268 {
 269         int i;
 270         int tms = 0;
 271         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 272         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 273
 274         for (i = 0; i < tms_count; i++) {
 275                 tms = (tms_scan >> i) & 1;
 276                 armjtagew_tap_append_step(tms, 0);
 277         }
 278
 279         tap_set_state(tap_get_end_state());
 280 }
 281
 282 static void armjtagew_path_move(int num_states, tap_state_t *path)
 283 {
 284         int i;
 285
 286         for (i = 0; i < num_states; i++) {
 287                 /*
 288                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 289                  * Either handle that here, or update the documentation with examples
 290                  * how to fix that in the configuration files.
 291                  */
 292                 if (path[i] == tap_state_transition(tap_get_state(), false))
 293                         armjtagew_tap_append_step(0, 0);
 294                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 295                         armjtagew_tap_append_step(1, 0);
 296                 else {
 297                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
 298                                 tap_state_name(tap_get_state()), tap_state_name(path[i]));
 299                         exit(-1);
 300                 }
 301
 302                 tap_set_state(path[i]);
 303         }
 304
 305         tap_set_end_state(tap_get_state());
 306 }
 307
 308 static void armjtagew_runtest(int num_cycles)
 309 {
 310         int i;
 311
 312         tap_state_t saved_end_state = tap_get_end_state();
 313
 314         /* only do a state_move when we're not already in IDLE */
 315         if (tap_get_state() != TAP_IDLE) {
 316                 armjtagew_end_state(TAP_IDLE);
 317                 armjtagew_state_move();
 318         }
 319
 320         /* execute num_cycles */
 321         for (i = 0; i < num_cycles; i++)
 322                 armjtagew_tap_append_step(0, 0);
 323
 324         /* finish in end_state */
 325         armjtagew_end_state(saved_end_state);
 326         if (tap_get_state() != tap_get_end_state())
 327                 armjtagew_state_move();
 328 }
 329
 330 static void armjtagew_scan(bool ir_scan,
 331         enum scan_type type,
 332         uint8_t *buffer,
 333         int scan_size,
 334         struct scan_command *command)
 335 {
 336         tap_state_t saved_end_state;
 337
 338         armjtagew_tap_ensure_space(1, scan_size + 8);
 339
 340         saved_end_state = tap_get_end_state();
 341
 342         /* Move to appropriate scan state */
 343         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 344
 345         /* Only move if we're not already there */
 346         if (tap_get_state() != tap_get_end_state())
 347                 armjtagew_state_move();
 348
 349         armjtagew_end_state(saved_end_state);
 350
 351         /* Scan */
 352         armjtagew_tap_append_scan(scan_size, buffer, command);
 353
 354         /* We are in Exit1, go to Pause */
 355         armjtagew_tap_append_step(0, 0);
 356
 357         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 358
 359         if (tap_get_state() != tap_get_end_state())
 360                 armjtagew_state_move();
 361 }
 362
 363 static void armjtagew_reset(int trst, int srst)
 364 {
 365         const uint8_t trst_mask = (1u << 5);
 366         const uint8_t srst_mask = (1u << 6);
 367         uint8_t val = 0;
 368         uint8_t outp_en = 0;
 369         uint8_t change_mask = 0;
 370         int result;
 371
 372         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 373
 374         if (srst == 0) {
 375                 val |= srst_mask;
 376                 outp_en &= ~srst_mask;          /* tristate */
 377                 change_mask |= srst_mask;
 378         } else if (srst == 1) {
 379                 val &= ~srst_mask;
 380                 outp_en |= srst_mask;
 381                 change_mask |= srst_mask;
 382         }
 383
 384         if (trst == 0) {
 385                 val |= trst_mask;
 386                 outp_en &= ~trst_mask;          /* tristate */
 387                 change_mask |= trst_mask;
 388         } else if (trst == 1) {
 389                 val &= ~trst_mask;
 390                 outp_en |= trst_mask;
 391                 change_mask |= trst_mask;
 392         }
 393
 394         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 395         usb_out_buffer[1] = val;
 396         usb_out_buffer[2] = outp_en;
 397         usb_out_buffer[3] = change_mask;
 398         result = armjtagew_usb_write(armjtagew_handle, 4);
 399         if (result != 4)
 400                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 401 }
 402
 403 static int armjtagew_get_status(void)
 404 {
 405         int result;
 406
 407         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 408         result = armjtagew_usb_message(armjtagew_handle, 1, 12);
 409
 410         if (result == 0) {
 411                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 412                 LOG_INFO(
 413                         "U_tg = %d mV, U_aux = %d mV, U_tgpwr = %d mV, I_tgpwr = %d mA, D1 = %d, Target power %s %s",
 414                         (int)(buf_get_u32(usb_in_buffer + 0, 0, 16)),
 415                         (int)(buf_get_u32(usb_in_buffer + 2, 0, 16)),
 416                         (int)(buf_get_u32(usb_in_buffer + 4, 0, 16)),
 417                         (int)(buf_get_u32(usb_in_buffer + 6, 0, 16)),
 418                         usb_in_buffer[9],
 419                         usb_in_buffer[11] ? "OVERCURRENT" : "OK",
 420                         usb_in_buffer[10] ? "enabled" : "disabled");
 421
 422                 if (u_tg < 1500)
 423                         LOG_ERROR("Vref too low. Check Target Power");
 424         } else
 425                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)", result);
 426
 427         return ERROR_OK;
 428 }
 429
 430 static int armjtagew_get_version_info(void)
 431 {
 432         int result;
 433         char sn[16];
 434         char auxinfo[257];
 435
 436         /* query hardware version */
 437         usb_out_buffer[0] = CMD_GET_VERSION;
 438         result = armjtagew_usb_message(armjtagew_handle, 1, 4 + 15 + 256);
 439
 440         if (result != 0) {
 441                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)", result);
 442                 return ERROR_JTAG_DEVICE_ERROR;
 443         }
 444
 445         memcpy(sn, usb_in_buffer + 4, 15);
 446         sn[15] = '\0';
 447         memcpy(auxinfo, usb_in_buffer + 4+15, 256);
 448         auxinfo[256] = '\0';
 449
 450         LOG_INFO(
 451                 "ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s",
 452                 usb_in_buffer[1],
 453                 usb_in_buffer[0],
 454                 isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X',
 455                 sn,
 456                 auxinfo);
 457
 458         if (1 != usb_in_buffer[1] || 6 != usb_in_buffer[0])
 459                 LOG_WARNING(
 460                         "ARM-JTAG-EW firmware version %d.%d is untested with this version of OpenOCD. You might experience unexpected behavior.",
 461                         usb_in_buffer[1],
 462                         usb_in_buffer[0]);
 463         return ERROR_OK;
 464 }
 465
 466 COMMAND_HANDLER(armjtagew_handle_armjtagew_info_command)
 467 {
 468         if (armjtagew_get_version_info() == ERROR_OK) {
 469                 /* attempt to get status */
 470                 armjtagew_get_status();
 471         }
 472
 473         return ERROR_OK;
 474 }
 475
 476 static const struct command_registration armjtagew_command_handlers[] = {
 477         {
 478                 .name = "armjtagew_info",
 479                 .handler = &armjtagew_handle_armjtagew_info_command,
 480                 .mode = COMMAND_EXEC,
 481                 .help = "query armjtagew info",
 482                 .usage = "",
 483         },
 484         COMMAND_REGISTRATION_DONE
 485 };
 486
 487 static struct jtag_interface armjtagew_interface = {
 488         .execute_queue = armjtagew_execute_queue,
 489 };
 490
 491 struct adapter_driver armjtagew_adapter_driver = {
 492         .name = "arm-jtag-ew",
 493         .transports = jtag_only,
 494         .commands = armjtagew_command_handlers,
 495
 496         .init = armjtagew_init,
 497         .quit = armjtagew_quit,
 498         .speed = armjtagew_speed,
 499         .khz = armjtagew_khz,
 500         .speed_div = armjtagew_speed_div,
 501
 502         .jtag_ops = &armjtagew_interface,
 503 };
 504
 505 /**************************************************************************
 506  * ARM-JTAG-EW tap functions */
 507
 508 /* 2048 is the max value we can use here */
 509 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 510
 511 static int tap_length;
 512 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 513 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 514 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 515
 516 struct pending_scan_result {
 517         int first;      /* First bit position in tdo_buffer to read */
 518         int length;     /* Number of bits to read */
 519         struct scan_command *command;   /* Corresponding scan command */
 520         uint8_t *buffer;
 521 };
 522
 523 #define MAX_PENDING_SCAN_RESULTS 256
 524
 525 static int pending_scan_results_length;
 526 static struct pending_scan_result pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 527
 528 static int last_tms;
 529
 530 static void armjtagew_tap_init(void)
 531 {
 532         tap_length = 0;
 533         pending_scan_results_length = 0;
 534 }
 535
 536 static void armjtagew_tap_ensure_space(int scans, int bits)
 537 {
 538         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 539         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 540
 541         if (scans > available_scans || bits > available_bits)
 542                 armjtagew_tap_execute();
 543 }
 544
 545 static void armjtagew_tap_append_step(int tms, int tdi)
 546 {
 547         last_tms = tms;
 548         int index_local = tap_length / 8;
 549
 550         if (index_local < ARMJTAGEW_TAP_BUFFER_SIZE) {
 551                 int bit_index = tap_length % 8;
 552                 uint8_t bit = 1 << bit_index;
 553
 554                 if (tms)
 555                         tms_buffer[index_local] |= bit;
 556                 else
 557                         tms_buffer[index_local] &= ~bit;
 558
 559                 if (tdi)
 560                         tdi_buffer[index_local] |= bit;
 561                 else
 562                         tdi_buffer[index_local] &= ~bit;
 563
 564                 tap_length++;
 565         } else
 566                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 567 }
 568
 569 void armjtagew_tap_append_scan(int length, uint8_t *buffer, struct scan_command *command)
 570 {
 571         struct pending_scan_result *pending_scan_result =
 572                 &pending_scan_results_buffer[pending_scan_results_length];
 573         int i;
 574
 575         pending_scan_result->first = tap_length;
 576         pending_scan_result->length = length;
 577         pending_scan_result->command = command;
 578         pending_scan_result->buffer = buffer;
 579
 580         for (i = 0; i < length; i++)
 581                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 582         pending_scan_results_length++;
 583 }
 584
 585 /* Pad and send a tap sequence to the device, and receive the answer.
 586  * For the purpose of padding we assume that we are in idle or pause state. */
 587 static int armjtagew_tap_execute(void)
 588 {
 589         int byte_length;
 590         int tms_offset;
 591         int tdi_offset;
 592         int i;
 593         int result;
 594
 595         if (tap_length > 0) {
 596                 /* Pad last byte so that tap_length is divisible by 8 */
 597                 while (tap_length % 8 != 0) {
 598                         /* More of the last TMS value keeps us in the same state,
 599                          * analogous to free-running JTAG interfaces. */
 600                         armjtagew_tap_append_step(last_tms, 0);
 601                 }
 602
 603                 byte_length = tap_length / 8;
 604
 605                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 606                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 607
 608                 tms_offset = 3;
 609                 for (i = 0; i < byte_length; i++)
 610                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i], 8);
 611
 612                 tdi_offset = tms_offset + byte_length;
 613                 for (i = 0; i < byte_length; i++)
 614                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i], 8);
 615
 616                 result = armjtagew_usb_message(armjtagew_handle,
 617                                 3 + 2 * byte_length,
 618                                 byte_length + 4);
 619
 620                 if (result == 0) {
 621                         int stat_local;
 622
 623                         stat_local = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 624                         if (stat_local) {
 625                                 LOG_ERROR(
 626                                         "armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command",
 627                                         stat_local);
 628                                 return ERROR_JTAG_QUEUE_FAILED;
 629                         }
 630
 631                         for (i = 0; i < byte_length; i++)
 632                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i], 8);
 633
 634                         for (i = 0; i < pending_scan_results_length; i++) {
 635                                 struct pending_scan_result *pending_scan_result =
 636                                         &pending_scan_results_buffer[i];
 637                                 uint8_t *buffer = pending_scan_result->buffer;
 638                                 int length = pending_scan_result->length;
 639                                 int first = pending_scan_result->first;
 640                                 struct scan_command *command = pending_scan_result->command;
 641
 642                                 /* Copy to buffer */
 643                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 644
 645                                 LOG_DEBUG_IO("pending scan result, length = %d", length);
 646
 647 #ifdef _DEBUG_USB_COMMS_
 648                                 armjtagew_debug_buffer(buffer, byte_length);
 649 #endif
 650
 651                                 if (jtag_read_buffer(buffer, command) != ERROR_OK) {
 652                                         armjtagew_tap_init();
 653                                         return ERROR_JTAG_QUEUE_FAILED;
 654                                 }
 655
 656                                 free(pending_scan_result->buffer);
 657                         }
 658                 } else {
 659                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d",
 660                                 result,
 661                                 byte_length);
 662                         return ERROR_JTAG_QUEUE_FAILED;
 663                 }
 664
 665                 armjtagew_tap_init();
 666         }
 667
 668         return ERROR_OK;
 669 }
 670
 671 /****************************************************************************
 672  * JLink USB low-level functions */
 673
 674 static struct armjtagew *armjtagew_usb_open(void)
 675 {
 676         const uint16_t vids[] = { USB_VID, 0 };
 677         const uint16_t pids[] = { USB_PID, 0 };
 678         struct libusb_device_handle *dev;
 679
 680         if (jtag_libusb_open(vids, pids, &dev, NULL) != ERROR_OK)
 681                 return NULL;
 682
 683         struct armjtagew *result = malloc(sizeof(struct armjtagew));
 684         result->usb_handle = dev;
 685
 686 #if 0
 687         /* libusb_set_configuration required under win32 */
 688         struct libusb_config_descriptor *config;
 689         struct libusb_device *usb_dev = libusb_get_device(dev);
 690         libusb_get_config_descriptor(usb_dev, 0, &config);
 691         libusb_set_configuration(dev, config->bConfigurationValue);
 692 #endif
 693         libusb_claim_interface(dev, 0);
 694 #if 0
 695         /*
 696          * This makes problems under Mac OS X. And is not needed
 697          * under Windows. Hopefully this will not break a linux build
 698          */
 699         libusb_set_interface_alt_setting(dev, 0, 0);
 700 #endif
 701         return result;
 702 }
 703
 704 static void armjtagew_usb_close(struct armjtagew *armjtagew)
 705 {
 706         libusb_close(armjtagew->usb_handle);
 707         free(armjtagew);
 708 }
 709
 710 /* Send a message and receive the reply. */
 711 static int armjtagew_usb_message(struct armjtagew *armjtagew, int out_length, int in_length)
 712 {
 713         int result;
 714
 715         result = armjtagew_usb_write(armjtagew, out_length);
 716         if (result == out_length) {
 717                 result = armjtagew_usb_read(armjtagew, in_length);
 718                 if (result != in_length) {
 719                         LOG_ERROR("jtag_libusb_bulk_read failed (requested=%d, result=%d)",
 720                                 in_length,
 721                                 result);
 722                         return -1;
 723                 }
 724         } else {
 725                 LOG_ERROR("jtag_libusb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 726                 return -1;
 727         }
 728         return 0;
 729 }
 730
 731 /* Write data from out_buffer to USB. */
 732 static int armjtagew_usb_write(struct armjtagew *armjtagew, int out_length)
 733 {
 734         int result;
 735         int transferred;
 736
 737         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE) {
 738                 LOG_ERROR("armjtagew_write illegal out_length=%d (max=%d)",
 739                         out_length,
 740                         ARMJTAGEW_OUT_BUFFER_SIZE);
 741                 return -1;
 742         }
 743
 744         result = jtag_libusb_bulk_write(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_OUT,
 745                         (char *)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT, &transferred);
 746
 747         LOG_DEBUG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 748
 749 #ifdef _DEBUG_USB_COMMS_
 750         armjtagew_debug_buffer(usb_out_buffer, out_length);
 751 #endif
 752         if (result != ERROR_OK)
 753                 return -1;
 754         return transferred;
 755 }
 756
 757 /* Read data from USB into in_buffer. */
 758 static int armjtagew_usb_read(struct armjtagew *armjtagew, int exp_in_length)
 759 {
 760         int transferred;
 761         int result = jtag_libusb_bulk_read(armjtagew->usb_handle, ARMJTAGEW_EPT_BULK_IN,
 762                         (char *)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT, &transferred);
 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         if (result != ERROR_OK)
 770                 return -1;
 771         return transferred;
 772 }
 773
 774 #ifdef _DEBUG_USB_COMMS_
 775 #define BYTES_PER_LINE  16
 776
 777 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 778 {
 779         char line[81];
 780         char s[4];
 781         int i;
 782         int j;
 783
 784         for (i = 0; i < length; i += BYTES_PER_LINE) {
 785                 snprintf(line, 5, "%04x", i);
 786                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++) {
 787                         snprintf(s, 4, " %02x", buffer[j]);
 788                         strcat(line, s);
 789                 }
 790                 LOG_DEBUG("%s", line);
 791
 792                 /* Prevent GDB timeout (writing to log might take some time) */
 793                 keep_alive();
 794         }
 795 }
 796 #endif