src/jtag/arm-jtag-ew.c

   1 /***************************************************************************
   2  *   Copyright (C) 2009 by Dimitar Dimitrov <dinuxbg@gmail.com>            *
   3  *   based on Dominic Rath's and Benedikt Sauter's usbprog.c               *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24
  25 #include "interface.h"
  26 #include "commands.h"
  27 #include <usb.h>
  28
  29
  30 #define USB_VID                                         0x15ba
  31 #define USB_PID                                         0x001e
  32
  33 #define ARMJTAGEW_EPT_BULK_OUT          0x01u
  34 #define ARMJTAGEW_EPT_BULK_IN           0x82u
  35
  36 #define ARMJTAGEW_USB_TIMEOUT           2000
  37
  38 #define ARMJTAGEW_IN_BUFFER_SIZE        (4*1024)
  39 #define ARMJTAGEW_OUT_BUFFER_SIZE       (4*1024)
  40
  41
  42 /* USB command request codes. */
  43 #define CMD_GET_VERSION                         0x00
  44 #define CMD_SELECT_DPIMPL                       0x10
  45 #define CMD_SET_TCK_FREQUENCY           0x11
  46 #define CMD_GET_TCK_FREQUENCY           0x12
  47 #define CMD_MEASURE_MAX_TCK_FREQ        0x15
  48 #define CMD_MEASURE_RTCK_RESPONSE       0x16
  49 #define CMD_TAP_SHIFT                           0x17
  50 #define CMD_SET_TAPHW_STATE                     0x20
  51 #define CMD_GET_TAPHW_STATE                     0x21
  52 #define CMD_TGPWR_SETUP                         0x22
  53
  54 /* Global USB buffers */
  55 static uint8_t usb_in_buffer[ARMJTAGEW_IN_BUFFER_SIZE];
  56 static uint8_t usb_out_buffer[ARMJTAGEW_OUT_BUFFER_SIZE];
  57
  58 /* External interface functions */
  59 static int armjtagew_execute_queue(void);
  60 static int armjtagew_speed(int speed);
  61 static int armjtagew_khz(int khz, int *jtag_speed);
  62 static int armjtagew_register_commands(struct command_context_s *cmd_ctx);
  63 static int armjtagew_init(void);
  64 static int armjtagew_quit(void);
  65
  66 /* CLI command handler functions */
  67 static int armjtagew_handle_armjtagew_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  68
  69 /* Queue command functions */
  70 static void armjtagew_end_state(tap_state_t state);
  71 static void armjtagew_state_move(void);
  72 static void armjtagew_path_move(int num_states, tap_state_t *path);
  73 static void armjtagew_runtest(int num_cycles);
  74 static void armjtagew_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command);
  75 static void armjtagew_reset(int trst, int srst);
  76 //static void armjtagew_simple_command(uint8_t command);
  77 static int armjtagew_get_status(void);
  78
  79 /* tap buffer functions */
  80 static void armjtagew_tap_init(void);
  81 static int armjtagew_tap_execute(void);
  82 static void armjtagew_tap_ensure_space(int scans, int bits);
  83 static void armjtagew_tap_append_step(int tms, int tdi);
  84 static void armjtagew_tap_append_scan(int length, uint8_t *buffer, scan_command_t *command);
  85
  86 /* ARM-JTAG-EW lowlevel functions */
  87 typedef struct armjtagew_jtag
  88 {
  89         struct usb_dev_handle* usb_handle;
  90 } armjtagew_jtag_t;
  91
  92 static armjtagew_jtag_t *armjtagew_usb_open(void);
  93 static void armjtagew_usb_close(armjtagew_jtag_t *armjtagew_jtag);
  94 static int armjtagew_usb_message(armjtagew_jtag_t *armjtagew_jtag, int out_length, int in_length);
  95 static int armjtagew_usb_write(armjtagew_jtag_t *armjtagew_jtag, int out_length);
  96 static int armjtagew_usb_read(armjtagew_jtag_t *armjtagew_jtag, int exp_in_length);
  97
  98 /* helper functions */
  99 static int armjtagew_get_version_info(void);
 100
 101 #ifdef _DEBUG_USB_COMMS_
 102 static void armjtagew_debug_buffer(uint8_t *buffer, int length);
 103 #endif
 104
 105 static armjtagew_jtag_t* armjtagew_jtag_handle;
 106
 107
 108
 109 /***************************************************************************/
 110 /* External interface implementation */
 111
 112 jtag_interface_t armjtagew_interface =
 113 {
 114         .name = "arm-jtag-ew",
 115         .execute_queue = armjtagew_execute_queue,
 116         .speed = armjtagew_speed,
 117         .khz = armjtagew_khz,
 118         .register_commands = armjtagew_register_commands,
 119         .init = armjtagew_init,
 120         .quit = armjtagew_quit
 121 };
 122
 123
 124 static int armjtagew_execute_queue(void)
 125 {
 126         jtag_command_t *cmd = jtag_command_queue;
 127         int scan_size;
 128         enum scan_type type;
 129         uint8_t *buffer;
 130
 131         while (cmd != NULL)
 132         {
 133                 switch (cmd->type)
 134                 {
 135                         case JTAG_RUNTEST:
 136                                 DEBUG_JTAG_IO("runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, \
 137                                         cmd->cmd.runtest->end_state);
 138
 139                                 armjtagew_end_state(cmd->cmd.runtest->end_state);
 140                                 armjtagew_runtest(cmd->cmd.runtest->num_cycles);
 141                                 break;
 142
 143                         case JTAG_STATEMOVE:
 144                                 DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 145
 146                                 armjtagew_end_state(cmd->cmd.statemove->end_state);
 147                                 armjtagew_state_move();
 148                                 break;
 149
 150                         case JTAG_PATHMOVE:
 151                                 DEBUG_JTAG_IO("pathmove: %i states, end in %i", \
 152                                         cmd->cmd.pathmove->num_states, \
 153                                         cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 154
 155                                 armjtagew_path_move(cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path);
 156                                 break;
 157
 158                         case JTAG_SCAN:
 159                                 DEBUG_JTAG_IO("scan end in %i", cmd->cmd.scan->end_state);
 160
 161                                 armjtagew_end_state(cmd->cmd.scan->end_state);
 162
 163                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 164                                 DEBUG_JTAG_IO("scan input, length = %d", scan_size);
 165
 166 #ifdef _DEBUG_USB_COMMS_
 167                                 armjtagew_debug_buffer(buffer, (scan_size + 7) / 8);
 168 #endif
 169                                 type = jtag_scan_type(cmd->cmd.scan);
 170                                 armjtagew_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size, cmd->cmd.scan);
 171                                 break;
 172
 173                         case JTAG_RESET:
 174                                 DEBUG_JTAG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 175
 176                                 armjtagew_tap_execute();
 177
 178                                 if (cmd->cmd.reset->trst == 1)
 179                                 {
 180                                         tap_set_state(TAP_RESET);
 181                                 }
 182                                 armjtagew_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 183                                 break;
 184
 185                         case JTAG_SLEEP:
 186                                 DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 187                                 armjtagew_tap_execute();
 188                                 jtag_sleep(cmd->cmd.sleep->us);
 189                                 break;
 190
 191                         default:
 192                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 193                                 exit(-1);
 194                 }
 195                 cmd = cmd->next;
 196         }
 197
 198         return armjtagew_tap_execute();
 199 }
 200
 201
 202 /* Sets speed in kHz. */
 203 static int armjtagew_speed(int speed)
 204 {
 205     int result;
 206     int speed_real;
 207
 208
 209     usb_out_buffer[0] = CMD_SET_TCK_FREQUENCY;
 210         buf_set_u32(usb_out_buffer + 1, 0, 32, speed);
 211
 212     result = armjtagew_usb_message(armjtagew_jtag_handle, 4, 4);
 213
 214     if (result < 0)
 215     {
 216         LOG_ERROR("ARM-JTAG-EW setting speed failed (%d)", result);
 217         return ERROR_JTAG_DEVICE_ERROR;
 218     }
 219
 220         usb_out_buffer[0] = CMD_GET_TCK_FREQUENCY;
 221     result = armjtagew_usb_message(armjtagew_jtag_handle, 1, 4);
 222         speed_real = (int)buf_get_u32(usb_in_buffer,0,32);
 223         if (result < 0)
 224         {
 225         LOG_ERROR("ARM-JTAG-EW getting speed failed (%d)", result);
 226         return ERROR_JTAG_DEVICE_ERROR;
 227         }
 228         else
 229         {
 230         LOG_INFO("Requested speed %dkHz, emulator reported %dkHz.", speed, speed_real);
 231         }
 232
 233     return ERROR_OK;
 234 }
 235
 236
 237 static int armjtagew_khz(int khz, int *jtag_speed)
 238 {
 239         *jtag_speed = khz;
 240
 241         return ERROR_OK;
 242 }
 243
 244 static int armjtagew_register_commands(struct command_context_s *cmd_ctx)
 245 {
 246         register_command(cmd_ctx, NULL, "armjtagew_info", armjtagew_handle_armjtagew_info_command, COMMAND_EXEC,
 247                 "query armjtagew info");
 248         return ERROR_OK;
 249 }
 250
 251 static int armjtagew_init(void)
 252 {
 253         int check_cnt;
 254
 255         armjtagew_jtag_handle = armjtagew_usb_open();
 256
 257         if (armjtagew_jtag_handle == 0)
 258         {
 259                 LOG_ERROR("Cannot find ARM-JTAG-EW Interface! Please check connection and permissions.");
 260                 return ERROR_JTAG_INIT_FAILED;
 261         }
 262
 263         check_cnt = 0;
 264         while (check_cnt < 3)
 265         {
 266                 if (armjtagew_get_version_info() == ERROR_OK)
 267                 {
 268                         /* attempt to get status */
 269                         armjtagew_get_status();
 270                         break;
 271                 }
 272
 273                 check_cnt++;
 274         }
 275
 276         if (check_cnt == 3)
 277         {
 278                 LOG_INFO("ARM-JTAG-EW initial read failed, don't worry");
 279         }
 280
 281         LOG_INFO("ARM-JTAG-EW JTAG Interface ready");
 282
 283         armjtagew_reset(0, 0);
 284         armjtagew_tap_init();
 285
 286         return ERROR_OK;
 287 }
 288
 289 static int armjtagew_quit(void)
 290 {
 291         armjtagew_usb_close(armjtagew_jtag_handle);
 292         return ERROR_OK;
 293 }
 294
 295 /***************************************************************************/
 296 /* Queue command implementations */
 297
 298 static void armjtagew_end_state(tap_state_t state)
 299 {
 300         if (tap_is_state_stable(state))
 301         {
 302                 tap_set_end_state(state);
 303         }
 304         else
 305         {
 306                 LOG_ERROR("BUG: %i is not a valid end state", state);
 307                 exit(-1);
 308         }
 309 }
 310
 311 /* Goes to the end state. */
 312 static void armjtagew_state_move(void)
 313 {
 314         int i;
 315         int tms = 0;
 316         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 317         int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 318
 319         for (i = 0; i < tms_count; i++)
 320         {
 321                 tms = (tms_scan >> i) & 1;
 322                 armjtagew_tap_append_step(tms, 0);
 323         }
 324
 325         tap_set_state(tap_get_end_state());
 326 }
 327
 328 static void armjtagew_path_move(int num_states, tap_state_t *path)
 329 {
 330         int i;
 331
 332         for (i = 0; i < num_states; i++)
 333         {
 334                 /*
 335                  * TODO: The ARM-JTAG-EW hardware delays TDI with 3 TCK cycles when in RTCK mode.
 336                  * Either handle that here, or update the documentation with examples
 337                  * how to fix that in the configuration files.
 338                  */
 339                 if (path[i] == tap_state_transition(tap_get_state(), false))
 340                 {
 341                         armjtagew_tap_append_step(0, 0);
 342                 }
 343                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 344                 {
 345                         armjtagew_tap_append_step(1, 0);
 346                 }
 347                 else
 348                 {
 349                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 350                         exit(-1);
 351                 }
 352
 353                 tap_set_state(path[i]);
 354         }
 355
 356         tap_set_end_state(tap_get_state());
 357 }
 358
 359 static void armjtagew_runtest(int num_cycles)
 360 {
 361         int i;
 362
 363         tap_state_t saved_end_state = tap_get_end_state();
 364
 365         /* only do a state_move when we're not already in IDLE */
 366         if (tap_get_state() != TAP_IDLE)
 367         {
 368                 armjtagew_end_state(TAP_IDLE);
 369                 armjtagew_state_move();
 370         }
 371
 372         /* execute num_cycles */
 373         for (i = 0; i < num_cycles; i++)
 374         {
 375                 armjtagew_tap_append_step(0, 0);
 376         }
 377
 378         /* finish in end_state */
 379         armjtagew_end_state(saved_end_state);
 380         if (tap_get_state() != tap_get_end_state())
 381         {
 382                 armjtagew_state_move();
 383         }
 384 }
 385
 386 static void armjtagew_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command)
 387 {
 388         tap_state_t saved_end_state;
 389
 390         armjtagew_tap_ensure_space(1, scan_size + 8);
 391
 392         saved_end_state = tap_get_end_state();
 393
 394         /* Move to appropriate scan state */
 395         armjtagew_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 396
 397         armjtagew_state_move();
 398         armjtagew_end_state(saved_end_state);
 399
 400         /* Scan */
 401         armjtagew_tap_append_scan(scan_size, buffer, command);
 402
 403         /* We are in Exit1, go to Pause */
 404         armjtagew_tap_append_step(0, 0);
 405
 406         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 407
 408         if (tap_get_state() != tap_get_end_state())
 409         {
 410                 armjtagew_state_move();
 411         }
 412 }
 413
 414 static void armjtagew_reset(int trst, int srst)
 415 {
 416         const uint8_t trst_mask = (1u << 5);
 417         const uint8_t srst_mask = (1u << 6);
 418         uint8_t val = 0;
 419         uint8_t outp_en = 0;
 420         uint8_t change_mask = 0;
 421         int result;
 422
 423         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 424
 425         if (srst == 0)
 426         {
 427                 val |= srst_mask;
 428                 outp_en &= ~srst_mask;          /* tristate */
 429                 change_mask |= srst_mask;
 430         }
 431         else if (srst == 1)
 432         {
 433                 val &= ~srst_mask;
 434                 outp_en |= srst_mask;
 435                 change_mask |= srst_mask;
 436         }
 437
 438         if (trst == 0)
 439         {
 440                 val |= trst_mask;
 441                 outp_en &= ~trst_mask;          /* tristate */
 442                 change_mask |= trst_mask;
 443         }
 444         else if (trst == 1)
 445         {
 446                 val &= ~trst_mask;
 447                 outp_en |= trst_mask;
 448                 change_mask |= trst_mask;
 449         }
 450
 451         usb_out_buffer[0] = CMD_SET_TAPHW_STATE;
 452         usb_out_buffer[1] = val;
 453         usb_out_buffer[2] = outp_en;
 454         usb_out_buffer[3] = change_mask;
 455         result = armjtagew_usb_write(armjtagew_jtag_handle, 4);
 456         if (result != 4)
 457         {
 458                 LOG_ERROR("ARM-JTAG-EW TRST/SRST pin set failed failed (%d)", result);
 459         }
 460 }
 461
 462
 463 static int armjtagew_get_status(void)
 464 {
 465         int result;
 466
 467         usb_out_buffer[0] = CMD_GET_TAPHW_STATE;
 468         result = armjtagew_usb_message(armjtagew_jtag_handle, 1, 12);
 469
 470         if (result == 0)
 471         {
 472                 unsigned int u_tg = buf_get_u32(usb_in_buffer, 0, 16);
 473                 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",
 474                          (int)(buf_get_u32(usb_in_buffer + 0, 0, 16)),
 475                          (int)(buf_get_u32(usb_in_buffer + 2, 0, 16)),
 476                          (int)(buf_get_u32(usb_in_buffer + 4, 0, 16)),
 477                          (int)(buf_get_u32(usb_in_buffer + 6, 0, 16)),
 478                          usb_in_buffer[9],
 479                          usb_in_buffer[11] ? "OVERCURRENT" : "OK",
 480                          usb_in_buffer[10] ? "enabled" : "disabled");
 481
 482                 if (u_tg < 1500)
 483                 {
 484                         LOG_ERROR("Vref too low. Check Target Power\n");
 485                 }
 486         }
 487         else
 488         {
 489                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_TAPHW_STATE failed (%d)\n", result);
 490         }
 491
 492         return ERROR_OK;
 493 }
 494
 495 static int armjtagew_get_version_info(void)
 496 {
 497         int result;
 498         char sn[16];
 499         char auxinfo[257];
 500
 501         /* query hardware version */
 502         usb_out_buffer[0] = CMD_GET_VERSION;
 503         result = armjtagew_usb_message(armjtagew_jtag_handle, 1, 4 + 15 + 256);
 504
 505         if (result != 0)
 506         {
 507                 LOG_ERROR("ARM-JTAG-EW command CMD_GET_VERSION failed (%d)\n", result);
 508                 return ERROR_JTAG_DEVICE_ERROR;
 509         }
 510
 511
 512         memcpy(sn, usb_in_buffer + 4, 15);
 513         sn[15] = '\0';
 514         memcpy(auxinfo, usb_in_buffer + 4+15, 256);
 515         auxinfo[256] = '\0';
 516
 517         LOG_INFO("ARM-JTAG-EW firmware version %d.%d, hardware revision %c, SN=%s, Additional info: %s", \
 518                         usb_in_buffer[1], usb_in_buffer[0], \
 519                         isgraph(usb_in_buffer[2]) ? usb_in_buffer[2] : 'X', \
 520                         sn, auxinfo);
 521         return ERROR_OK;
 522 }
 523
 524 static int armjtagew_handle_armjtagew_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 525 {
 526         if (armjtagew_get_version_info() == ERROR_OK)
 527         {
 528                 /* attempt to get status */
 529                 armjtagew_get_status();
 530         }
 531
 532         return ERROR_OK;
 533 }
 534
 535 /***************************************************************************/
 536 /* ARM-JTAG-EW tap functions */
 537
 538 /* 2048 is the max value we can use here */
 539 #define ARMJTAGEW_TAP_BUFFER_SIZE 2048
 540
 541 static int tap_length;
 542 static uint8_t tms_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 543 static uint8_t tdi_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 544 static uint8_t tdo_buffer[ARMJTAGEW_TAP_BUFFER_SIZE];
 545
 546 typedef struct
 547 {
 548         int first;      /* First bit position in tdo_buffer to read */
 549         int length; /* Number of bits to read */
 550         scan_command_t *command; /* Corresponding scan command */
 551         uint8_t *buffer;
 552 } pending_scan_result_t;
 553
 554 #define MAX_PENDING_SCAN_RESULTS 256
 555
 556 static int pending_scan_results_length;
 557 static pending_scan_result_t pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 558
 559 static int last_tms;
 560
 561 static void armjtagew_tap_init(void)
 562 {
 563         tap_length = 0;
 564         pending_scan_results_length = 0;
 565 }
 566
 567 static void armjtagew_tap_ensure_space(int scans, int bits)
 568 {
 569         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 570         int available_bits = ARMJTAGEW_TAP_BUFFER_SIZE * 8 - tap_length;
 571
 572         if (scans > available_scans || bits > available_bits)
 573         {
 574                 armjtagew_tap_execute();
 575         }
 576 }
 577
 578 static void armjtagew_tap_append_step(int tms, int tdi)
 579 {
 580         last_tms = tms;
 581         int index = tap_length / 8;
 582
 583         if (index < ARMJTAGEW_TAP_BUFFER_SIZE)
 584         {
 585                 int bit_index = tap_length % 8;
 586                 uint8_t bit = 1 << bit_index;
 587
 588                 if (tms)
 589                 {
 590                         tms_buffer[index] |= bit;
 591                 }
 592                 else
 593                 {
 594                         tms_buffer[index] &= ~bit;
 595                 }
 596
 597                 if (tdi)
 598                 {
 599                         tdi_buffer[index] |= bit;
 600                 }
 601                 else
 602                 {
 603                         tdi_buffer[index] &= ~bit;
 604                 }
 605
 606                 tap_length++;
 607         }
 608         else
 609         {
 610                 LOG_ERROR("armjtagew_tap_append_step, overflow");
 611         }
 612 }
 613
 614 void armjtagew_tap_append_scan(int length, uint8_t *buffer, scan_command_t *command)
 615 {
 616         pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
 617         int i;
 618
 619         pending_scan_result->first = tap_length;
 620         pending_scan_result->length = length;
 621         pending_scan_result->command = command;
 622         pending_scan_result->buffer = buffer;
 623
 624         for (i = 0; i < length; i++)
 625         {
 626                 armjtagew_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 627         }
 628         pending_scan_results_length++;
 629 }
 630
 631 /* Pad and send a tap sequence to the device, and receive the answer.
 632  * For the purpose of padding we assume that we are in idle or pause state. */
 633 static int armjtagew_tap_execute(void)
 634 {
 635         int byte_length;
 636         int tms_offset;
 637         int tdi_offset;
 638         int i;
 639         int result;
 640
 641         if (tap_length > 0)
 642         {
 643                 /* Pad last byte so that tap_length is divisible by 8 */
 644                 while (tap_length % 8 != 0)
 645                 {
 646                         /* More of the last TMS value keeps us in the same state,
 647                          * analogous to free-running JTAG interfaces. */
 648                         armjtagew_tap_append_step(last_tms, 0);
 649                 }
 650
 651                 byte_length = tap_length / 8;
 652
 653                 usb_out_buffer[0] = CMD_TAP_SHIFT;
 654                 buf_set_u32(usb_out_buffer + 1, 0, 16, byte_length);
 655
 656                 tms_offset = 3;
 657                 for (i = 0; i < byte_length; i++)
 658                 {
 659                         usb_out_buffer[tms_offset + i] = flip_u32(tms_buffer[i],8);
 660                 }
 661
 662                 tdi_offset = tms_offset + byte_length;
 663                 for (i = 0; i < byte_length; i++)
 664                 {
 665                         usb_out_buffer[tdi_offset + i] = flip_u32(tdi_buffer[i],8);
 666                 }
 667
 668                 result = armjtagew_usb_message(armjtagew_jtag_handle, 3 + 2 * byte_length, byte_length + 4);
 669
 670                 if (result == 0)
 671                 {
 672                         int stat;
 673
 674                         stat = (int)buf_get_u32(usb_in_buffer + byte_length, 0, 32);
 675                         if (stat) {
 676                                 LOG_ERROR("armjtagew_tap_execute, emulator returned error code %d for a CMD_TAP_SHIFT command", stat);
 677                                 return ERROR_JTAG_QUEUE_FAILED;
 678                         }
 679
 680                         for (i = 0; i < byte_length; i++)
 681                         {
 682                                 tdo_buffer[i] = flip_u32(usb_in_buffer[i],8);
 683                         }
 684
 685                         for (i = 0; i < pending_scan_results_length; i++)
 686                         {
 687                                 pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
 688                                 uint8_t *buffer = pending_scan_result->buffer;
 689                                 int length = pending_scan_result->length;
 690                                 int first = pending_scan_result->first;
 691                                 scan_command_t *command = pending_scan_result->command;
 692
 693                                 /* Copy to buffer */
 694                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 695
 696                                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 697
 698 #ifdef _DEBUG_USB_COMMS_
 699                                 armjtagew_debug_buffer(buffer, byte_length);
 700 #endif
 701
 702                                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 703                                 {
 704                                         armjtagew_tap_init();
 705                                         return ERROR_JTAG_QUEUE_FAILED;
 706                                 }
 707
 708                                 if (pending_scan_result->buffer != NULL)
 709                                 {
 710                                         free(pending_scan_result->buffer);
 711                                 }
 712                         }
 713                 }
 714                 else
 715                 {
 716                         LOG_ERROR("armjtagew_tap_execute, wrong result %d, expected %d", result, byte_length);
 717                         return ERROR_JTAG_QUEUE_FAILED;
 718                 }
 719
 720                 armjtagew_tap_init();
 721         }
 722
 723         return ERROR_OK;
 724 }
 725
 726 /*****************************************************************************/
 727 /* JLink USB low-level functions */
 728
 729 static armjtagew_jtag_t* armjtagew_usb_open()
 730 {
 731         struct usb_bus *busses;
 732         struct usb_bus *bus;
 733         struct usb_device *dev;
 734
 735         armjtagew_jtag_t *result;
 736
 737         result = (armjtagew_jtag_t*) malloc(sizeof(armjtagew_jtag_t));
 738
 739         usb_init();
 740         usb_find_busses();
 741         usb_find_devices();
 742
 743         busses = usb_get_busses();
 744
 745         /* find armjtagew_jtag device in usb bus */
 746
 747         for (bus = busses; bus; bus = bus->next)
 748         {
 749                 for (dev = bus->devices; dev; dev = dev->next)
 750                 {
 751                         if ((dev->descriptor.idVendor == USB_VID) && (dev->descriptor.idProduct == USB_PID))
 752                         {
 753                                 result->usb_handle = usb_open(dev);
 754
 755 #if 0
 756                                 /* usb_set_configuration required under win32 */
 757                                 usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
 758 #endif
 759                                 usb_claim_interface(result->usb_handle, 0);
 760
 761 #if 0
 762                                 /*
 763                                  * This makes problems under Mac OS X. And is not needed
 764                                  * under Windows. Hopefully this will not break a linux build
 765                                  */
 766                                 usb_set_altinterface(result->usb_handle, 0);
 767 #endif
 768                                 return result;
 769                         }
 770                 }
 771         }
 772
 773         free(result);
 774         return NULL;
 775 }
 776
 777 static void armjtagew_usb_close(armjtagew_jtag_t *armjtagew_jtag)
 778 {
 779         usb_close(armjtagew_jtag->usb_handle);
 780         free(armjtagew_jtag);
 781 }
 782
 783 /* Send a message and receive the reply. */
 784 static int armjtagew_usb_message(armjtagew_jtag_t *armjtagew_jtag, int out_length, int in_length)
 785 {
 786         int result;
 787
 788         result = armjtagew_usb_write(armjtagew_jtag, out_length);
 789         if (result == out_length)
 790         {
 791                 result = armjtagew_usb_read(armjtagew_jtag, in_length);
 792                 if (result != in_length)
 793                 {
 794                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)", in_length, result);
 795                         return -1;
 796                 }
 797         }
 798         else
 799         {
 800                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 801                 return -1;
 802         }
 803         return 0;
 804 }
 805
 806 /* Write data from out_buffer to USB. */
 807 static int armjtagew_usb_write(armjtagew_jtag_t *armjtagew_jtag, int out_length)
 808 {
 809         int result;
 810
 811         if (out_length > ARMJTAGEW_OUT_BUFFER_SIZE)
 812         {
 813                 LOG_ERROR("armjtagew_jtag_write illegal out_length=%d (max=%d)", out_length, ARMJTAGEW_OUT_BUFFER_SIZE);
 814                 return -1;
 815         }
 816
 817         result = usb_bulk_write(armjtagew_jtag->usb_handle, ARMJTAGEW_EPT_BULK_OUT, \
 818                 (char*)usb_out_buffer, out_length, ARMJTAGEW_USB_TIMEOUT);
 819
 820         DEBUG_JTAG_IO("armjtagew_usb_write, out_length = %d, result = %d", out_length, result);
 821
 822 #ifdef _DEBUG_USB_COMMS_
 823         armjtagew_debug_buffer(usb_out_buffer, out_length);
 824 #endif
 825         return result;
 826 }
 827
 828 /* Read data from USB into in_buffer. */
 829 static int armjtagew_usb_read(armjtagew_jtag_t *armjtagew_jtag, int exp_in_length)
 830 {
 831         int result = usb_bulk_read(armjtagew_jtag->usb_handle, ARMJTAGEW_EPT_BULK_IN, \
 832                 (char*)usb_in_buffer, exp_in_length, ARMJTAGEW_USB_TIMEOUT);
 833
 834         DEBUG_JTAG_IO("armjtagew_usb_read, result = %d", result);
 835
 836 #ifdef _DEBUG_USB_COMMS_
 837         armjtagew_debug_buffer(usb_in_buffer, result);
 838 #endif
 839         return result;
 840 }
 841
 842
 843 #ifdef _DEBUG_USB_COMMS_
 844 #define BYTES_PER_LINE  16
 845
 846 static void armjtagew_debug_buffer(uint8_t *buffer, int length)
 847 {
 848         char line[81];
 849         char s[4];
 850         int i;
 851         int j;
 852
 853         for (i = 0; i < length; i += BYTES_PER_LINE)
 854         {
 855                 snprintf(line, 5, "%04x", i);
 856                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
 857                 {
 858                         snprintf(s, 4, " %02x", buffer[j]);
 859                         strcat(line, s);
 860                 }
 861                 LOG_DEBUG("%s", line);
 862         }
 863 }
 864 #endif
 865