src/jtag/arm-jtag-ew.c

   1 // vim:ts=4 sw=4:
   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  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  21  ***************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include "config.h"
  25 #endif
  26
  27 #include "interface.h"
  28 #include "commands.h"
  29 #include <usb.h>
  30
  31
  32 #define USB_VID                                         0x15ba
  33 #define USB_PID                                         0x001e
  34
  35 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  36 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  37
  38 #define ARMJTAGEW_USB_TIMEOUT           2000
  39
  40 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  41 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  42
  43
  44 /* USB command request codes. */
  45 #define CMD_GET_VERSION                         0x00
  46 #define CMD_SELECT_DPIMPL                       0x10
  47 #define CMD_SET_TCK_FREQUENCY           0x11
  48 #define CMD_GET_TCK_FREQUENCY           0x12
  49 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  50 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  51 #define CMD_TAP_SHIFT                           0x17
  52 #define CMD_SET_TAPHW_STATE                     0x20
  53 #define CMD_GET_TAPHW_STATE                     0x21
  54 #define CMD_TGPWR_SETUP                         0x22
  55
  56 /* Global USB buffers */
  57 static u8 usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  58 static u8 usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  59
  60 /* External interface functions */
  61 static int armjtagew_execute_queue(void);
  62 static int armjtagew_speed(int speed);
  63 static int armjtagew_khz(int khz, int *jtag_speed);
  64 static int armjtagew_register_commands(struct command_context_s *cmd_ctx);
  65 static int armjtagew_init(void);
  66 static int armjtagew_quit(void);
  67
  68 /* CLI command handler functions */
  69 static int armjtagew_handle_armjtagew_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  70
  71 /* Queue command functions */
  72 static void armjtagew_end_state(tap_state_t state);
  73 static void armjtagew_state_move(void);
  74 static void armjtagew_path_move(int num_states, tap_state_t *path);
  75 static void armjtagew_runtest(int num_cycles);
  76 static void armjtagew_scan(bool ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command);
  77 static void armjtagew_reset(int trst, int srst);
  78 //static void armjtagew_simple_command(u8 command);
  79 static int armjtagew_get_status(void);
  80
  81 /* tap buffer functions */
  82 static void armjtagew_tap_init(void);
  83 static int armjtagew_tap_execute(void);
  84 static void armjtagew_tap_ensure_space(int scans, int bits);
  85 static void armjtagew_tap_append_step(int tms, int tdi);
  86 static void armjtagew_tap_append_scan(int length, u8 *buffer, scan_command_t *command);
  87
  88 /* ARM-JTAG-EW lowlevel functions */
  89 typedef struct armjtagew_jtag
  90 {
  91         struct usb_dev_handle* usb_handle;
  92 } armjtagew_jtag_t;
  93
  94 static armjtagew_jtag_t *armjtagew_usb_open(void);
  95 static void armjtagew_usb_close(armjtagew_jtag_t *armjtagew_jtag);
  96 static int armjtagew_usb_message(armjtagew_jtag_t *armjtagew_jtag, int out_length, int in_length);
  97 static int armjtagew_usb_write(armjtagew_jtag_t *armjtagew_jtag, int out_length);
  98 static int armjtagew_usb_read(armjtagew_jtag_t *armjtagew_jtag, int exp_in_length);
  99
 100 /* helper functions */
 101 static int armjtagew_get_version_info(void);
 102
 103 #ifdef _DEBUG_USB_COMMS_
 104 static void armjtagew_debug_buffer(u8 *buffer, int length);
 105 #endif
 106
 107 static armjtagew_jtag_t* armjtagew_jtag_handle;
 108
 109
 110
 111 /***************************************************************************/
 112 /* External interface implementation */
 113
 114 jtag_interface_t armjtagew_interface =
 115 {
 116         .name = "arm-jtag-ew",
 117         .execute_queue = armjtagew_execute_queue,
 118         .speed = armjtagew_speed,
 119         .khz = armjtagew_khz,
 120         .register_commands = armjtagew_register_commands,
 121         .init = armjtagew_init,
 122         .quit = armjtagew_quit
 123 };
 124
 125
 126 static int armjtagew_execute_queue(void)
 127 {
 128         jtag_command_t *cmd = jtag_command_queue;
 129         int scan_size;
 130         enum scan_type type;
 131         u8 *buffer;
 132
 133         while (cmd != NULL)
 134         {
 135                 switch (cmd->type)
 136                 {
 137                         case JTAG_RUNTEST:
 138                                 DEBUG_JTAG_IO( "runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, \
 139                                         cmd->cmd.runtest->end_state);
 140
 141                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 142                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 143                                 break;
 144
 145                         case JTAG_STATEMOVE:
 146                                 DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 147
 148                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 149                                 armjtagew_state_move();
 150                                 break;
 151
 152                         case JTAG_PATHMOVE:
 153                                 DEBUG_JTAG_IO("pathmove: %i states, end in %i", \
 154                                         cmd->cmd.pathmove->num_states, \
 155                                         cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 156
 157                                 armjtagew_path_move(cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path);
 158                                 break;
 159
 160                         case JTAG_SCAN:
 161                                 DEBUG_JTAG_IO("scan end in %i", cmd->cmd.scan->end_state);
 162
 163                                 armjtagew_end_state(cmd->cmd.scan->end_state);
 164
 165                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 166                                 DEBUG_JTAG_IO("scan input, length = %d", scan_size);
 167
 168 #ifdef _DEBUG_USB_COMMS_
 169                                 armjtagew_debug_buffer(buffer, (scan_size + 7) / 8);
 170 #endif
 171                                 type = jtag_scan_type(cmd->cmd.scan);
 172                                 armjtagew_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size, cmd->cmd.scan);
 173                                 break;
 174
 175                         case JTAG_RESET:
 176                                 DEBUG_JTAG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 177
 178                                 armjtagew_tap_execute();
 179
 180                                 if (cmd->cmd.reset->trst == 1)
 181                                 {
 182                                         tap_set_state(TAP_RESET);
 183                                 }
 184                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 185                                 break;
 186
 187                         case JTAG_SLEEP:
 188                                 DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 189                                 armjtagew_tap_execute();
 190                                 jtag_sleep(cmd->cmd.sleep->us);
 191                                 break;
 192
 193                         default:
 194                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 195                                 exit(-1);
 196                 }
 197                 cmd = cmd->next;
 198         }
 199
 200         return armjtagew_tap_execute();
 201 }
 202
 203
 204 /* Sets speed in kHz. */
 205 static int armjtagew_speed(int speed)
 206 {
 207     int result;
 208     int speed_real;
 209
 210
 211     usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 212         buf_set_u32(usb_out_buffer+1, 0, 32, speed);
 213
 214     result = armjtagew_usb_message(armjtagew_jtag_handle, 4, 4);
 215
 216     if (result < 0)
 217     {
 218         LOG_ERROR("ARM-JTAG-EW setting speed failed (%d)", result);
 219         return ERROR_JTAG_DEVICE_ERROR;
 220     }
 221
 222         usb_out_buffer[0] = CMD_GET_TCK_FREQUENCY;
 223     result = armjtagew_usb_message(armjtagew_jtag_handle, 1, 4);
 224         speed_real = (int)buf_get_u32(usb_in_buffer,0,32);
 225         if(result < 0)
 226         {
 227         LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 228         return ERROR_JTAG_DEVICE_ERROR;
 229         }
 230         else
 231         {
 232         LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 233         }
 234
 235     return ERROR_OK;
 236 }
 237
 238
 239 static int armjtagew_khz(int khz, int *jtag_speed)
 240 {
 241         *jtag_speed = khz;
 242
 243         return ERROR_OK;
 244 }
 245
 246 static int armjtagew_register_commands(struct command_context_s *cmd_ctx)
 247 {
 248         register_command(cmd_ctx, NULL, "armjtagew_info", armjtagew_handle_armjtagew_info_command, COMMAND_EXEC,
 249                 "query armjtagew info");
 250         return ERROR_OK;
 251 }
 252
 253 static int armjtagew_init(void)
 254 {
 255         int check_cnt;
 256
 257         armjtagew_jtag_handle = armjtagew_usb_open();
 258
 259         if (armjtagew_jtag_handle == 0)
 260         {
 261                 LOG_ERROR("Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 262                 return ERROR_JTAG_INIT_FAILED;
 263         }
 264
 265         check_cnt = 0;
 266         while (check_cnt < 3)
 267         {
 268                 if (armjtagew_get_version_info() == ERROR_OK)
 269                 {
 270                         /* attempt to get status */
 271                         armjtagew_get_status();
 272                         break;
 273                 }
 274
 275                 check_cnt++;
 276         }
 277
 278         if (check_cnt == 3)
 279         {
 280                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 281         }
 282
 283         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 284
 285         armjtagew_reset(0, 0);
 286         armjtagew_tap_init();
 287
 288         return ERROR_OK;
 289 }
 290
 291 static int armjtagew_quit(void)
 292 {
 293         armjtagew_usb_close(armjtagew_jtag_handle);
 294         return ERROR_OK;
 295 }
 296
 297 /***************************************************************************/
 298 /* Queue command implementations */
 299
 300 static void armjtagew_end_state(tap_state_t state)
 301 {
 302         if (tap_is_state_stable(state))
 303         {
 304                 tap_set_end_state(state);
 305         }
 306         else
 307         {
 308                 LOG_ERROR("BUG: %i is not a valid end state", state);
 309                 exit(-1);
 310         }
 311 }
 312
 313 /* Goes to the end state. */
 314 static void armjtagew_state_move(void)
 315 {
 316         int i;
 317         int tms = 0;
 318         u8 tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 319         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 320
 321         for (i = 0; i < tms_count; i++)
 322         {
 323                 tms = (tms_scan >> i) & 1;
 324                 armjtagew_tap_append_step(tms, 0);
 325         }
 326
 327         tap_set_state(tap_get_end_state());
 328 }
 329
 330 static void armjtagew_path_move(int num_states, tap_state_t *path)
 331 {
 332         int i;
 333
 334         for (i = 0; i < num_states; i++)
 335         {
 336                 /*
 337                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 338                  * Either handle that here, or update the documentation with examples
 339                  * how to fix that in the configuration files.
 340                  */
 341                 if (path[i] == tap_state_transition(tap_get_state(), false))
 342                 {
 343                         armjtagew_tap_append_step(0, 0);
 344                 }
 345                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 346                 {
 347                         armjtagew_tap_append_step(1, 0);
 348                 }
 349                 else
 350                 {
 351                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 352                         exit(-1);
 353                 }
 354
 355                 tap_set_state(path[i]);
 356         }
 357
 358         tap_set_end_state(tap_get_state());
 359 }
 360
 361 static void armjtagew_runtest(int num_cycles)
 362 {
 363         int i;
 364
 365         tap_state_t saved_end_state = tap_get_end_state();
 366
 367         /* only do a state_move when we're not already in IDLE */
 368         if (tap_get_state() != TAP_IDLE)
 369         {
 370                 armjtagew_end_state(TAP_IDLE);
 371                 armjtagew_state_move();
 372         }
 373
 374         /* execute num_cycles */
 375         for (i = 0; i < num_cycles; i++)
 376         {
 377                 armjtagew_tap_append_step(0, 0);
 378         }
 379
 380         /* finish in end_state */
 381         armjtagew_end_state(saved_end_state);
 382         if (tap_get_state() != tap_get_end_state())
 383         {
 384                 armjtagew_state_move();
 385         }
 386 }
 387
 388 static void armjtagew_scan(bool ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command)
 389 {
 390         tap_state_t saved_end_state;
 391
 392         armjtagew_tap_ensure_space(1, scan_size + 8);
 393
 394         saved_end_state = tap_get_end_state();
 395
 396         /* Move to appropriate scan state */
 397         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 398
 399         armjtagew_state_move();
 400         armjtagew_end_state(saved_end_state);
 401
 402         /* Scan */
 403         armjtagew_tap_append_scan(scan_size, buffer, command);
 404
 405         /* We are in Exit1, go to Pause */
 406         armjtagew_tap_append_step(0, 0);
 407
 408         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 409
 410         if (tap_get_state() != tap_get_end_state())
 411         {
 412                 armjtagew_state_move();
 413         }
 414 }
 415
 416 static void armjtagew_reset(int trst, int srst)
 417 {
 418         const u8 trst_mask = (1u<<5);
 419         const u8 srst_mask = (1u<<6);
 420         u8 val = 0;
 421         u8 outp_en = 0;
 422         u8 change_mask = 0;
 423         int result;
 424
 425         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 426
 427         if (srst == 0)
 428         {
 429                 val |= srst_mask;
 430                 outp_en &= ~srst_mask;          /* tristate */
 431                 change_mask |= srst_mask;
 432         }
 433         else if (srst == 1)
 434         {
 435                 val &= ~srst_mask;
 436                 outp_en |= srst_mask;
 437                 change_mask |= srst_mask;
 438         }
 439
 440         if (trst == 0)
 441         {
 442                 val |= trst_mask;
 443                 outp_en &= ~trst_mask;          /* tristate */
 444                 change_mask |= trst_mask;
 445         }
 446         else if (trst == 1)
 447         {
 448                 val &= ~trst_mask;
 449                 outp_en |= trst_mask;
 450                 change_mask |= trst_mask;
 451         }
 452
 453         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 454         usb_out_buffer[1] = val;
 455         usb_out_buffer[2] = outp_en;
 456         usb_out_buffer[3] = change_mask;
 457         result = armjtagew_usb_write(armjtagew_jtag_handle, 4);
 458         if (result != 4)
 459         {
 460                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 461         }
 462 }
 463
 464
 465 static int armjtagew_get_status(void)
 466 {
 467         int result;
 468
 469         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 470         result = armjtagew_usb_message(armjtagew_jtag_handle, 1, 12);
 471
 472         if (result == 0)
 473         {
 474                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 475                 LOG_INFO("U_tg = %d mV, U_aux = %d mV, U_tgpwr = %d mV, I_tgpwr = %d mA, D1 = %d, Target power %s %s\n", \
 476                         buf_get_u32(usb_in_buffer + 0, 0, 16), \
 477                         buf_get_u32(usb_in_buffer + 2, 0, 16), \
 478                         buf_get_u32(usb_in_buffer + 4, 0, 16), \
 479                         buf_get_u32(usb_in_buffer + 6, 0, 16), \
 480                         usb_in_buffer[9], \
 481                         usb_in_buffer[11] ? "OVERCURRENT" : "OK", \
 482                         usb_in_buffer[10] ? "enabled" : "disabled");
 483
 484                 if (u_tg < 1500)
 485                 {
 486                         LOG_ERROR("Vref too low. Check Target Power\n");
 487                 }
 488         }
 489         else
 490         {
 491                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)\n", result);
 492         }
 493
 494         return ERROR_OK;
 495 }
 496
 497 static int armjtagew_get_version_info(void)
 498 {
 499         int result;
 500         char sn[16];
 501         char auxinfo[257];
 502
 503         /* query hardware version */
 504         usb_out_buffer[0] = CMD_GET_VERSION;
 505         result = armjtagew_usb_message(armjtagew_jtag_handle, 1, 4+15+256);
 506
 507         if (result != 0)
 508         {
 509                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)\n", result);
 510                 return ERROR_JTAG_DEVICE_ERROR;
 511         }
 512
 513
 514         memcpy(sn, usb_in_buffer+4, 15);
 515         sn[15] = '\0';
 516         memcpy(auxinfo, usb_in_buffer+4+15, 256);
 517         auxinfo[256] = '\0';
 518
 519         LOG_INFO("ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s", \
 520                         usb_in_buffer[1], usb_in_buffer[0], \
 521                         isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X', \
 522                         sn, auxinfo);
 523         return ERROR_OK;
 524 }
 525
 526 static int armjtagew_handle_armjtagew_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 527 {
 528         if (armjtagew_get_version_info() == ERROR_OK)
 529         {
 530                 /* attempt to get status */
 531                 armjtagew_get_status();
 532         }
 533
 534         return ERROR_OK;
 535 }
 536
 537 /***************************************************************************/
 538 /* ARM-JTAG-EW tap functions */
 539
 540 /* 2048 is the max value we can use here */
 541 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 542
 543 static int tap_length;
 544 static u8 tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 545 static u8 tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 546 static u8 tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 547
 548 typedef struct
 549 {
 550         int first;      /* First bit position in tdo_buffer to read */
 551         int length; /* Number of bits to read */
 552         scan_command_t *command; /* Corresponding scan command */
 553         u8 *buffer;
 554 } pending_scan_result_t;
 555
 556 #define MAX_PENDING_SCAN_RESULTS 256
 557
 558 static int pending_scan_results_length;
 559 static pending_scan_result_t pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 560
 561 static int last_tms;
 562
 563 static void armjtagew_tap_init(void)
 564 {
 565         tap_length = 0;
 566         pending_scan_results_length = 0;
 567 }
 568
 569 static void armjtagew_tap_ensure_space(int scans, int bits)
 570 {
 571         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 572         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 573
 574         if (scans > available_scans || bits > available_bits)
 575         {
 576                 armjtagew_tap_execute();
 577         }
 578 }
 579
 580 static void armjtagew_tap_append_step(int tms, int tdi)
 581 {
 582         last_tms = tms;
 583         int index = tap_length / 8;
 584
 585         if (index < ARMJTAGEW_TAP_BUFFER_SIZE)
 586         {
 587                 int bit_index = tap_length % 8;
 588                 u8 bit = 1 << bit_index;
 589
 590                 if (tms)
 591                 {
 592                         tms_buffer[index] |= bit;
 593                 }
 594                 else
 595                 {
 596                         tms_buffer[index] &= ~bit;
 597                 }
 598
 599                 if (tdi)
 600                 {
 601                         tdi_buffer[index] |= bit;
 602                 }
 603                 else
 604                 {
 605                         tdi_buffer[index] &= ~bit;
 606                 }
 607
 608                 tap_length++;
 609         }
 610         else
 611         {
 612                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 613         }
 614 }
 615
 616 void armjtagew_tap_append_scan(int length, u8 *buffer, scan_command_t *command)
 617 {
 618         pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
 619         int i;
 620
 621         pending_scan_result->first = tap_length;
 622         pending_scan_result->length = length;
 623         pending_scan_result->command = command;
 624         pending_scan_result->buffer = buffer;
 625
 626         for (i = 0; i < length; i++)
 627         {
 628                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 629         }
 630         pending_scan_results_length++;
 631 }
 632
 633 /* Pad and send a tap sequence to the device, and receive the answer.
 634  * For the purpose of padding we assume that we are in idle or pause state. */
 635 static int armjtagew_tap_execute(void)
 636 {
 637         int byte_length;
 638         int tms_offset;
 639         int tdi_offset;
 640         int i;
 641         int result;
 642
 643         if (tap_length > 0)
 644         {
 645                 /* Pad last byte so that tap_length is divisible by 8 */
 646                 while (tap_length % 8 != 0)
 647                 {
 648                         /* More of the last TMS value keeps us in the same state,
 649                          * analogous to free-running JTAG interfaces. */
 650                         armjtagew_tap_append_step(last_tms, 0);
 651                 }
 652
 653                 byte_length = tap_length / 8;
 654
 655                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 656                 buf_set_u32(usb_out_buffer+1, 0, 16, byte_length);
 657
 658                 tms_offset = 3;
 659                 for (i = 0; i < byte_length; i++)
 660                 {
 661                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i],8);
 662                 }
 663
 664                 tdi_offset = tms_offset + byte_length;
 665                 for (i = 0; i < byte_length; i++)
 666                 {
 667                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i],8);
 668                 }
 669
 670                 result = armjtagew_usb_message(armjtagew_jtag_handle, 3 + 2 * byte_length, byte_length + 4);
 671
 672                 if (result == 0)
 673                 {
 674                         int stat;
 675
 676                         stat = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 677                         if(stat) {
 678                                 LOG_ERROR("armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command", stat);
 679                                 return ERROR_JTAG_QUEUE_FAILED;
 680                         }
 681
 682                         for (i = 0; i < byte_length; i++)
 683                         {
 684                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i],8);
 685                         }
 686
 687                         for (i = 0; i < pending_scan_results_length; i++)
 688                         {
 689                                 pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
 690                                 u8 *buffer = pending_scan_result->buffer;
 691                                 int length = pending_scan_result->length;
 692                                 int first = pending_scan_result->first;
 693                                 scan_command_t *command = pending_scan_result->command;
 694
 695                                 /* Copy to buffer */
 696                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 697
 698                                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 699
 700 #ifdef _DEBUG_USB_COMMS_
 701                                 armjtagew_debug_buffer(buffer, byte_length);
 702 #endif
 703
 704                                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 705                                 {
 706                                         armjtagew_tap_init();
 707                                         return ERROR_JTAG_QUEUE_FAILED;
 708                                 }
 709
 710                                 if (pending_scan_result->buffer != NULL)
 711                                 {
 712                                         free(pending_scan_result->buffer);
 713                                 }
 714                         }
 715                 }
 716                 else
 717                 {
 718                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d", result, byte_length);
 719                         return ERROR_JTAG_QUEUE_FAILED;
 720                 }
 721
 722                 armjtagew_tap_init();
 723         }
 724
 725         return ERROR_OK;
 726 }
 727
 728 /*****************************************************************************/
 729 /* JLink USB low-level functions */
 730
 731 static armjtagew_jtag_t* armjtagew_usb_open()
 732 {
 733         struct usb_bus *busses;
 734         struct usb_bus *bus;
 735         struct usb_device *dev;
 736
 737         armjtagew_jtag_t *result;
 738
 739         result = (armjtagew_jtag_t*) malloc(sizeof(armjtagew_jtag_t));
 740
 741         usb_init();
 742         usb_find_busses();
 743         usb_find_devices();
 744
 745         busses = usb_get_busses();
 746
 747         /* find armjtagew_jtag device in usb bus */
 748
 749         for (bus = busses; bus; bus = bus->next)
 750         {
 751                 for (dev = bus->devices; dev; dev = dev->next)
 752                 {
 753                         if ((dev->descriptor.idVendor == USB_VID) && (dev->descriptor.idProduct == USB_PID))
 754                         {
 755                                 result->usb_handle = usb_open(dev);
 756
 757 #if 0
 758                                 /* usb_set_configuration required under win32 */
 759                                 usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
 760 #endif
 761                                 usb_claim_interface(result->usb_handle, 0);
 762
 763 #if 0
 764                                 /*
 765                                  * This makes problems under Mac OS X. And is not needed
 766                                  * under Windows. Hopefully this will not break a linux build
 767                                  */
 768                                 usb_set_altinterface(result->usb_handle, 0);
 769 #endif
 770                                 return result;
 771                         }
 772                 }
 773         }
 774
 775         free(result);
 776         return NULL;
 777 }
 778
 779 static void armjtagew_usb_close(armjtagew_jtag_t *armjtagew_jtag)
 780 {
 781         usb_close(armjtagew_jtag->usb_handle);
 782         free(armjtagew_jtag);
 783 }
 784
 785 /* Send a message and receive the reply. */
 786 static int armjtagew_usb_message(armjtagew_jtag_t *armjtagew_jtag, int out_length, int in_length)
 787 {
 788         int result;
 789
 790         result = armjtagew_usb_write(armjtagew_jtag, out_length);
 791         if (result == out_length)
 792         {
 793                 result = armjtagew_usb_read(armjtagew_jtag, in_length);
 794                 if (result != in_length)
 795                 {
 796                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)", in_length, result);
 797                         return -1;
 798                 }
 799         }
 800         else
 801         {
 802                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 803                 return -1;
 804         }
 805         return 0;
 806 }
 807
 808 /* Write data from out_buffer to USB. */
 809 static int armjtagew_usb_write(armjtagew_jtag_t *armjtagew_jtag, int out_length)
 810 {
 811         int result;
 812
 813         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE)
 814         {
 815                 LOG_ERROR("armjtagew_jtag_write illegal out_length=%d (max=%d)", out_length, ARMJTAGEW_OUT_BUFFER_SIZE);
 816                 return -1;
 817         }
 818
 819         result = usb_bulk_write(armjtagew_jtag->usb_handle, ARMJTAGEW_EPT_BULK_OUT, \
 820                 (char*)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT);
 821
 822         DEBUG_JTAG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 823
 824 #ifdef _DEBUG_USB_COMMS_
 825         armjtagew_debug_buffer(usb_out_buffer, out_length);
 826 #endif
 827         return result;
 828 }
 829
 830 /* Read data from USB into in_buffer. */
 831 static int armjtagew_usb_read(armjtagew_jtag_t *armjtagew_jtag, int exp_in_length)
 832 {
 833         int result = usb_bulk_read(armjtagew_jtag->usb_handle, ARMJTAGEW_EPT_BULK_IN, \
 834                 (char*)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT);
 835
 836         DEBUG_JTAG_IO("armjtagew_usb_read, result = %d", result);
 837
 838 #ifdef _DEBUG_USB_COMMS_
 839         armjtagew_debug_buffer(usb_in_buffer, result);
 840 #endif
 841         return result;
 842 }
 843
 844
 845 #ifdef _DEBUG_USB_COMMS_
 846 #define BYTES_PER_LINE  16
 847
 848 static void armjtagew_debug_buffer(u8 *buffer, int length)
 849 {
 850         char line[81];
 851         char s[4];
 852         int i;
 853         int j;
 854
 855         for (i = 0; i < length; i += BYTES_PER_LINE)
 856         {
 857                 snprintf(line, 5, "%04x", i);
 858                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
 859                 {
 860                         snprintf(s, 4, " %02x", buffer[j]);
 861                         strcat(line, s);
 862                 }
 863                 LOG_DEBUG("%s", line);
 864         }
 865 }
 866 #endif
 867