git.sur5r.net Git - openocd/blob - src/jtag/jlink.c

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by Juergen Stuber <juergen@jstuber.net>            *
   3  *   based on Dominic Rath's and Benedikt Sauter's usbprog.c               *
   4  *                                                                         *
   5  *   Copyright (C) 2008 by Spencer Oliver                                  *
   6  *   spen@spen-soft.co.uk                                                  *
   7  *                                                                         *
   8  *   This program is free software; you can redistribute it and/or modify  *
   9  *   it under the terms of the GNU General Public License as published by  *
  10  *   the Free Software Foundation; either version 2 of the License, or     *
  11  *   (at your option) any later version.                                   *
  12  *                                                                         *
  13  *   This program is distributed in the hope that it will be useful,       *
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  16  *   GNU General Public License for more details.                          *
  17  *                                                                         *
  18  *   You should have received a copy of the GNU General Public License     *
  19  *   along with this program; if not, write to the                         *
  20  *   Free Software Foundation, Inc.,                                       *
  21  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  22  ***************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif
  27
  28 #include "replacements.h"
  29
  30 #include "jtag.h"
  31
  32 #include <usb.h>
  33 #include <string.h>
  34
  35 #include "log.h"
  36
  37 #define VID 0x1366
  38 #define PID 0x0101
  39
  40 #define JLINK_WRITE_ENDPOINT    0x02
  41 #define JLINK_READ_ENDPOINT             0x81
  42
  43 #define JLINK_USB_TIMEOUT               1000
  44
  45 #define JLINK_IN_BUFFER_SIZE                    8192
  46 #define JLINK_OUT_BUFFER_SIZE                   8192
  47 #define JLINK_EMU_RESULT_BUFFER_SIZE    64
  48
  49 /* Global USB buffers */
  50 static u8 usb_in_buffer[JLINK_IN_BUFFER_SIZE];
  51 static u8 usb_out_buffer[JLINK_OUT_BUFFER_SIZE];
  52 static u8 usb_emu_result_buffer[JLINK_EMU_RESULT_BUFFER_SIZE];
  53
  54 /* Constants for JLink command */
  55 #define EMU_CMD_VERSION     0x01
  56 #define EMU_CMD_SET_SPEED   0x05
  57 #define EMU_CMD_GET_STATE   0x07
  58 #define EMU_CMD_HW_JTAG3    0xcf
  59 #define EMU_CMD_HW_RESET0   0xdc
  60 #define EMU_CMD_HW_RESET1   0xdd
  61 #define EMU_CMD_HW_TRST0    0xde
  62 #define EMU_CMD_HW_TRST1    0xdf
  63
  64 /* max speed 12MHz v5.0 jlink */
  65 #define JLINK_MAX_SPEED 12000
  66
  67 /* External interface functions */
  68 static int jlink_execute_queue(void);
  69 static int jlink_speed(int speed);
  70 static int jlink_speed_div(int speed, int* khz);
  71 static int jlink_khz(int khz, int *jtag_speed);
  72 static int jlink_register_commands(struct command_context_s *cmd_ctx);
  73 static int jlink_init(void);
  74 static int jlink_quit(void);
  75
  76 /* CLI command handler functions */
  77 static int jlink_handle_jlink_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  78
  79 /* Queue command functions */
  80 static void jlink_end_state(tap_state_t state);
  81 static void jlink_state_move(void);
  82 static void jlink_path_move(int num_states, tap_state_t *path);
  83 static void jlink_runtest(int num_cycles);
  84 static void jlink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command);
  85 static void jlink_reset(int trst, int srst);
  86 static void jlink_simple_command(u8 command);
  87 static int jlink_get_status(void);
  88
  89 /* J-Link tap buffer functions */
  90 static void jlink_tap_init(void);
  91 static int jlink_tap_execute(void);
  92 static void jlink_tap_ensure_space(int scans, int bits);
  93 static void jlink_tap_append_step(int tms, int tdi);
  94 static void jlink_tap_append_scan(int length, u8 *buffer, scan_command_t *command);
  95
  96 /* Jlink lowlevel functions */
  97 typedef struct jlink_jtag
  98 {
  99         struct usb_dev_handle* usb_handle;
 100 } jlink_jtag_t;
 101
 102 static jlink_jtag_t *jlink_usb_open(void);
 103 static void jlink_usb_close(jlink_jtag_t *jlink_jtag);
 104 static int jlink_usb_message(jlink_jtag_t *jlink_jtag, int out_length, int in_length);
 105 static int jlink_usb_write(jlink_jtag_t *jlink_jtag, int out_length);
 106 static int jlink_usb_read(jlink_jtag_t *jlink_jtag, int expected_size);
 107 static int jlink_usb_read_emu_result(jlink_jtag_t *jlink_jtag);
 108
 109 /* helper functions */
 110 static int jlink_get_version_info(void);
 111
 112 #ifdef _DEBUG_USB_COMMS_
 113 static void jlink_debug_buffer(u8 *buffer, int length);
 114 #endif
 115
 116 static jlink_jtag_t* jlink_jtag_handle;
 117
 118 /***************************************************************************/
 119 /* External interface implementation */
 120
 121 jtag_interface_t jlink_interface =
 122 {
 123         .name = "jlink",
 124         .execute_queue = jlink_execute_queue,
 125         .speed = jlink_speed,
 126         .speed_div = jlink_speed_div,
 127         .khz = jlink_khz,
 128         .register_commands = jlink_register_commands,
 129         .init = jlink_init,
 130         .quit = jlink_quit
 131 };
 132
 133 static int jlink_execute_queue(void)
 134 {
 135         jtag_command_t *cmd = jtag_command_queue;
 136         int scan_size;
 137         enum scan_type type;
 138         u8 *buffer;
 139
 140         while (cmd != NULL)
 141         {
 142                 switch (cmd->type)
 143                 {
 144                         case JTAG_END_STATE:
 145                                 DEBUG_JTAG_IO("end_state: %i", cmd->cmd.end_state->end_state);
 146
 147                                 if (cmd->cmd.end_state->end_state != TAP_INVALID)
 148                                 {
 149                                         jlink_end_state(cmd->cmd.end_state->end_state);
 150                                 }
 151                                 break;
 152
 153                         case JTAG_RUNTEST:
 154                                 DEBUG_JTAG_IO( "runtest %i cycles, end in %i", cmd->cmd.runtest->num_cycles, \
 155                                         cmd->cmd.runtest->end_state);
 156
 157                                 if (cmd->cmd.runtest->end_state != TAP_INVALID)
 158                                 {
 159                                         jlink_end_state(cmd->cmd.runtest->end_state);
 160                                 }
 161                                 jlink_runtest(cmd->cmd.runtest->num_cycles);
 162                                 break;
 163
 164                         case JTAG_STATEMOVE:
 165                                 DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 166
 167                                 if (cmd->cmd.statemove->end_state != TAP_INVALID)
 168                                 {
 169                                         jlink_end_state(cmd->cmd.statemove->end_state);
 170                                 }
 171                                 jlink_state_move();
 172                                 break;
 173
 174                         case JTAG_PATHMOVE:
 175                                 DEBUG_JTAG_IO("pathmove: %i states, end in %i", \
 176                                         cmd->cmd.pathmove->num_states, \
 177                                         cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 178
 179                                 jlink_path_move(cmd->cmd.pathmove->num_states, cmd->cmd.pathmove->path);
 180                                 break;
 181
 182                         case JTAG_SCAN:
 183                                 DEBUG_JTAG_IO("scan end in %i", cmd->cmd.scan->end_state);
 184
 185                                 if (cmd->cmd.scan->end_state != TAP_INVALID)
 186                                 {
 187                                         jlink_end_state(cmd->cmd.scan->end_state);
 188                                 }
 189
 190                                 scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 191                                 DEBUG_JTAG_IO("scan input, length = %d", scan_size);
 192
 193 #ifdef _DEBUG_USB_COMMS_
 194                                 jlink_debug_buffer(buffer, (scan_size + 7) / 8);
 195 #endif
 196                                 type = jtag_scan_type(cmd->cmd.scan);
 197                                 jlink_scan(cmd->cmd.scan->ir_scan, type, buffer, scan_size, cmd->cmd.scan);
 198                                 break;
 199
 200                         case JTAG_RESET:
 201                                 DEBUG_JTAG_IO("reset trst: %i srst %i", cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 202
 203                                 jlink_tap_execute();
 204
 205                                 if (cmd->cmd.reset->trst == 1)
 206                                 {
 207                                         tap_set_state(TAP_RESET);
 208                                 }
 209                                 jlink_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 210                                 break;
 211
 212                         case JTAG_SLEEP:
 213                                 DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 214                                 jlink_tap_execute();
 215                                 jtag_sleep(cmd->cmd.sleep->us);
 216                                 break;
 217
 218                         default:
 219                                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 220                                 exit(-1);
 221                 }
 222                 cmd = cmd->next;
 223         }
 224
 225         return jlink_tap_execute();
 226 }
 227
 228 /* Sets speed in kHz. */
 229 static int jlink_speed(int speed)
 230 {
 231         int result;
 232
 233         if (speed <= JLINK_MAX_SPEED)
 234         {
 235                 /* check for RTCK setting */
 236                 if (speed == 0)
 237                         speed = -1;
 238
 239                 usb_out_buffer[0] = EMU_CMD_SET_SPEED;
 240                 usb_out_buffer[1] = (speed >> 0) & 0xff;
 241                 usb_out_buffer[2] = (speed >> 8) & 0xff;
 242
 243                 result = jlink_usb_write(jlink_jtag_handle, 3);
 244
 245                 if (result == 3)
 246                 {
 247                         return ERROR_OK;
 248                 }
 249                 else
 250                 {
 251                         LOG_ERROR("J-Link setting speed failed (%d)", result);
 252                         return ERROR_JTAG_DEVICE_ERROR;
 253                 }
 254         }
 255         else
 256         {
 257                 LOG_INFO("Requested speed %dkHz exceeds maximum of %dkHz, ignored", speed, JLINK_MAX_SPEED);
 258         }
 259
 260         return ERROR_OK;
 261 }
 262
 263 static int jlink_speed_div(int speed, int* khz)
 264 {
 265         *khz = speed;
 266
 267         return ERROR_OK;
 268 }
 269
 270 static int jlink_khz(int khz, int *jtag_speed)
 271 {
 272         *jtag_speed = khz;
 273
 274         return ERROR_OK;
 275 }
 276
 277 static int jlink_register_commands(struct command_context_s *cmd_ctx)
 278 {
 279         register_command(cmd_ctx, NULL, "jlink_info", jlink_handle_jlink_info_command, COMMAND_EXEC,
 280                 "query jlink info");
 281         return ERROR_OK;
 282 }
 283
 284 static int jlink_init(void)
 285 {
 286         int check_cnt;
 287
 288         jlink_jtag_handle = jlink_usb_open();
 289
 290         if (jlink_jtag_handle == 0)
 291         {
 292                 LOG_ERROR("Cannot find jlink Interface! Please check connection and permissions.");
 293                 return ERROR_JTAG_INIT_FAILED;
 294         }
 295
 296         check_cnt = 0;
 297         while (check_cnt < 3)
 298         {
 299                 if (jlink_get_version_info() == ERROR_OK)
 300                 {
 301                         /* attempt to get status */
 302                         jlink_get_status();
 303                         break;
 304                 }
 305
 306                 check_cnt++;
 307         }
 308
 309         if (check_cnt == 3)
 310         {
 311                 LOG_INFO("J-Link initial read failed, don't worry");
 312         }
 313
 314         LOG_INFO("J-Link JTAG Interface ready");
 315
 316         jlink_reset(0, 0);
 317         jlink_tap_init();
 318
 319         return ERROR_OK;
 320 }
 321
 322 static int jlink_quit(void)
 323 {
 324         jlink_usb_close(jlink_jtag_handle);
 325         return ERROR_OK;
 326 }
 327
 328 /***************************************************************************/
 329 /* Queue command implementations */
 330
 331 static void jlink_end_state(tap_state_t state)
 332 {
 333         if (tap_is_state_stable(state))
 334         {
 335                 tap_set_end_state(state);
 336         }
 337         else
 338         {
 339                 LOG_ERROR("BUG: %i is not a valid end state", state);
 340                 exit(-1);
 341         }
 342 }
 343
 344 /* Goes to the end state. */
 345 static void jlink_state_move(void)
 346 {
 347         int i;
 348         int tms = 0;
 349         u8 tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 350
 351         for (i = 0; i < 7; i++)
 352         {
 353                 tms = (tms_scan >> i) & 1;
 354                 jlink_tap_append_step(tms, 0);
 355         }
 356
 357         tap_set_state(tap_get_end_state());
 358 }
 359
 360 static void jlink_path_move(int num_states, tap_state_t *path)
 361 {
 362         int i;
 363
 364         for (i = 0; i < num_states; i++)
 365         {
 366                 if (path[i] == tap_state_transition(tap_get_state(), false))
 367                 {
 368                         jlink_tap_append_step(0, 0);
 369                 }
 370                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 371                 {
 372                         jlink_tap_append_step(1, 0);
 373                 }
 374                 else
 375                 {
 376                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 377                         exit(-1);
 378                 }
 379
 380                 tap_set_state(path[i]);
 381         }
 382
 383         tap_set_end_state(tap_get_state());
 384 }
 385
 386 static void jlink_runtest(int num_cycles)
 387 {
 388         int i;
 389
 390         tap_state_t saved_end_state = tap_get_end_state();
 391
 392         /* only do a state_move when we're not already in IDLE */
 393         if (tap_get_state() != TAP_IDLE)
 394         {
 395                 jlink_end_state(TAP_IDLE);
 396                 jlink_state_move();
 397         }
 398
 399         /* execute num_cycles */
 400         for (i = 0; i < num_cycles; i++)
 401         {
 402                 jlink_tap_append_step(0, 0);
 403         }
 404
 405         /* finish in end_state */
 406         jlink_end_state(saved_end_state);
 407         if (tap_get_state() != tap_get_end_state())
 408         {
 409                 jlink_state_move();
 410         }
 411 }
 412
 413 static void jlink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command)
 414 {
 415         tap_state_t saved_end_state;
 416
 417         jlink_tap_ensure_space(1, scan_size + 8);
 418
 419         saved_end_state = tap_get_end_state();
 420
 421         /* Move to appropriate scan state */
 422         jlink_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 423
 424         /* Only move if we're not already there */
 425         if (tap_get_state() != tap_get_end_state())
 426                 jlink_state_move();
 427
 428         jlink_end_state(saved_end_state);
 429
 430         /* Scan */
 431         jlink_tap_append_scan(scan_size, buffer, command);
 432
 433         /* We are in Exit1, go to Pause */
 434         jlink_tap_append_step(0, 0);
 435
 436         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 437
 438         if (tap_get_state() != tap_get_end_state())
 439         {
 440                 jlink_state_move();
 441         }
 442 }
 443
 444 static void jlink_reset(int trst, int srst)
 445 {
 446         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 447
 448         /* Signals are active low */
 449         if (srst == 0)
 450         {
 451                 jlink_simple_command(EMU_CMD_HW_RESET1);
 452         }
 453         else if (srst == 1)
 454         {
 455                 jlink_simple_command(EMU_CMD_HW_RESET0);
 456         }
 457
 458         if (trst == 0)
 459         {
 460                 jlink_simple_command(EMU_CMD_HW_TRST1);
 461         }
 462         else if (trst == 1)
 463         {
 464                 jlink_simple_command(EMU_CMD_HW_TRST0);
 465         }
 466 }
 467
 468 static void jlink_simple_command(u8 command)
 469 {
 470         int result;
 471
 472         DEBUG_JTAG_IO("0x%02x", command);
 473
 474         usb_out_buffer[0] = command;
 475         result = jlink_usb_write(jlink_jtag_handle, 1);
 476
 477         if (result != 1)
 478         {
 479                 LOG_ERROR("J-Link command 0x%02x failed (%d)", command, result);
 480         }
 481 }
 482
 483 static int jlink_get_status(void)
 484 {
 485         int result;
 486
 487         jlink_simple_command(EMU_CMD_GET_STATE);
 488         result = jlink_usb_read(jlink_jtag_handle, 8);
 489
 490         if (result == 8)
 491         {
 492                 int vref = usb_in_buffer[0] + (usb_in_buffer[1] << 8);
 493                 LOG_INFO("Vref = %d.%d TCK = %d TDI = %d TDO = %d TMS = %d SRST = %d TRST = %d\n", \
 494                         vref / 1000, vref % 1000, \
 495                         usb_in_buffer[2], usb_in_buffer[3], usb_in_buffer[4], \
 496                         usb_in_buffer[5], usb_in_buffer[6], usb_in_buffer[7]);
 497
 498                 if (vref < 1500)
 499                 {
 500                         LOG_ERROR("Vref too low. Check Target Power\n");
 501                 }
 502         }
 503         else
 504         {
 505                 LOG_ERROR("J-Link command EMU_CMD_GET_STATE failed (%d)\n", result);
 506         }
 507
 508         return ERROR_OK;
 509 }
 510
 511 static int jlink_get_version_info(void)
 512 {
 513         int result;
 514         int len = 0;
 515
 516         /* query hardware version */
 517         jlink_simple_command(EMU_CMD_VERSION);
 518         result = jlink_usb_read(jlink_jtag_handle, 2);
 519
 520         if (result == 2)
 521         {
 522                 len = buf_get_u32(usb_in_buffer, 0, 16);
 523                 result = jlink_usb_read(jlink_jtag_handle, len);
 524
 525                 if (result == len)
 526                 {
 527                         usb_in_buffer[result] = 0;
 528                         LOG_INFO("%s", (char *)usb_in_buffer);
 529                         return ERROR_OK;
 530                 }
 531         }
 532
 533         LOG_ERROR("J-Link command EMU_CMD_VERSION failed (%d)\n", result);
 534         return ERROR_JTAG_DEVICE_ERROR;
 535 }
 536
 537 static int jlink_handle_jlink_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 538 {
 539         if (jlink_get_version_info() == ERROR_OK)
 540         {
 541                 /* attempt to get status */
 542                 jlink_get_status();
 543         }
 544
 545         return ERROR_OK;
 546 }
 547
 548 /***************************************************************************/
 549 /* J-Link tap functions */
 550
 551 /* 2048 is the max value we can use here */
 552 #define JLINK_TAP_BUFFER_SIZE 2048
 553
 554 static int tap_length;
 555 static u8 tms_buffer[JLINK_TAP_BUFFER_SIZE];
 556 static u8 tdi_buffer[JLINK_TAP_BUFFER_SIZE];
 557 static u8 tdo_buffer[JLINK_TAP_BUFFER_SIZE];
 558
 559 typedef struct
 560 {
 561         int first;      /* First bit position in tdo_buffer to read */
 562         int length; /* Number of bits to read */
 563         scan_command_t *command; /* Corresponding scan command */
 564         u8 *buffer;
 565 } pending_scan_result_t;
 566
 567 #define MAX_PENDING_SCAN_RESULTS 256
 568
 569 static int pending_scan_results_length;
 570 static pending_scan_result_t pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 571
 572 static int last_tms;
 573
 574 static void jlink_tap_init(void)
 575 {
 576         tap_length = 0;
 577         pending_scan_results_length = 0;
 578 }
 579
 580 static void jlink_tap_ensure_space(int scans, int bits)
 581 {
 582         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 583         int available_bits = JLINK_TAP_BUFFER_SIZE * 8 - tap_length;
 584
 585         if (scans > available_scans || bits > available_bits)
 586         {
 587                 jlink_tap_execute();
 588         }
 589 }
 590
 591 static void jlink_tap_append_step(int tms, int tdi)
 592 {
 593         last_tms = tms;
 594         int index = tap_length / 8;
 595
 596         if (index < JLINK_TAP_BUFFER_SIZE)
 597         {
 598                 int bit_index = tap_length % 8;
 599                 u8 bit = 1 << bit_index;
 600
 601                 if (tms)
 602                 {
 603                         tms_buffer[index] |= bit;
 604                 }
 605                 else
 606                 {
 607                         tms_buffer[index] &= ~bit;
 608                 }
 609
 610                 if (tdi)
 611                 {
 612                         tdi_buffer[index] |= bit;
 613                 }
 614                 else
 615                 {
 616                         tdi_buffer[index] &= ~bit;
 617                 }
 618
 619                 tap_length++;
 620         }
 621         else
 622         {
 623                 LOG_ERROR("jlink_tap_append_step, overflow");
 624         }
 625 }
 626
 627 static void jlink_tap_append_scan(int length, u8 *buffer, scan_command_t *command)
 628 {
 629         pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[pending_scan_results_length];
 630         int i;
 631
 632         pending_scan_result->first = tap_length;
 633         pending_scan_result->length = length;
 634         pending_scan_result->command = command;
 635         pending_scan_result->buffer = buffer;
 636
 637         for (i = 0; i < length; i++)
 638         {
 639                 jlink_tap_append_step((i < length-1 ? 0 : 1), (buffer[i/8] >> (i%8)) & 1);
 640         }
 641         pending_scan_results_length++;
 642 }
 643
 644 /* Pad and send a tap sequence to the device, and receive the answer.
 645  * For the purpose of padding we assume that we are in idle or pause state. */
 646 static int jlink_tap_execute(void)
 647 {
 648         int byte_length;
 649         int tms_offset;
 650         int tdi_offset;
 651         int i;
 652         int result;
 653
 654         if (tap_length > 0)
 655         {
 656                 /* Pad last byte so that tap_length is divisible by 8 */
 657                 while (tap_length % 8 != 0)
 658                 {
 659                         /* More of the last TMS value keeps us in the same state,
 660                          * analogous to free-running JTAG interfaces. */
 661                         jlink_tap_append_step(last_tms, 0);
 662                 }
 663
 664                 byte_length = tap_length / 8;
 665
 666                 usb_out_buffer[0] = EMU_CMD_HW_JTAG3;
 667                 usb_out_buffer[1] = 0;
 668                 usb_out_buffer[2] = (tap_length >> 0) & 0xff;
 669                 usb_out_buffer[3] = (tap_length >> 8) & 0xff;
 670
 671                 tms_offset = 4;
 672                 for (i = 0; i < byte_length; i++)
 673                 {
 674                         usb_out_buffer[tms_offset + i] = tms_buffer[i];
 675                 }
 676
 677                 tdi_offset = tms_offset + byte_length;
 678                 for (i = 0; i < byte_length; i++)
 679                 {
 680                         usb_out_buffer[tdi_offset + i] = tdi_buffer[i];
 681                 }
 682
 683                 result = jlink_usb_message(jlink_jtag_handle, 4 + 2 * byte_length, byte_length);
 684
 685                 if (result == byte_length)
 686                 {
 687                         for (i = 0; i < byte_length; i++)
 688                         {
 689                                 tdo_buffer[i] = usb_in_buffer[i];
 690                         }
 691
 692                         for (i = 0; i < pending_scan_results_length; i++)
 693                         {
 694                                 pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
 695                                 u8 *buffer = pending_scan_result->buffer;
 696                                 int length = pending_scan_result->length;
 697                                 int first = pending_scan_result->first;
 698                                 scan_command_t *command = pending_scan_result->command;
 699
 700                                 /* Copy to buffer */
 701                                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 702
 703                                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 704
 705 #ifdef _DEBUG_USB_COMMS_
 706                                 jlink_debug_buffer(buffer, byte_length);
 707 #endif
 708
 709                                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 710                                 {
 711                                         jlink_tap_init();
 712                                         return ERROR_JTAG_QUEUE_FAILED;
 713                                 }
 714
 715                                 if (pending_scan_result->buffer != NULL)
 716                                 {
 717                                         free(pending_scan_result->buffer);
 718                                 }
 719                         }
 720                 }
 721                 else
 722                 {
 723                         LOG_ERROR("jlink_tap_execute, wrong result %d, expected %d", result, byte_length);
 724                         return ERROR_JTAG_QUEUE_FAILED;
 725                 }
 726
 727                 jlink_tap_init();
 728         }
 729
 730         return ERROR_OK;
 731 }
 732
 733 /*****************************************************************************/
 734 /* JLink USB low-level functions */
 735
 736 static jlink_jtag_t* jlink_usb_open()
 737 {
 738         struct usb_bus *busses;
 739         struct usb_bus *bus;
 740         struct usb_device *dev;
 741
 742         jlink_jtag_t *result;
 743
 744         result = (jlink_jtag_t*) malloc(sizeof(jlink_jtag_t));
 745
 746         usb_init();
 747         usb_find_busses();
 748         usb_find_devices();
 749
 750         busses = usb_get_busses();
 751
 752         /* find jlink_jtag device in usb bus */
 753
 754         for (bus = busses; bus; bus = bus->next)
 755         {
 756                 for (dev = bus->devices; dev; dev = dev->next)
 757                 {
 758                         if ((dev->descriptor.idVendor == VID) && (dev->descriptor.idProduct == PID))
 759                         {
 760                                 result->usb_handle = usb_open(dev);
 761
 762                                 /* usb_set_configuration required under win32 */
 763                                 usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
 764                                 usb_claim_interface(result->usb_handle, 0);
 765
 766 #if 0
 767                                 /*
 768                                  * This makes problems under Mac OS X. And is not needed
 769                                  * under Windows. Hopefully this will not break a linux build
 770                                  */
 771                                 usb_set_altinterface(result->usb_handle, 0);
 772 #endif
 773                                 return result;
 774                         }
 775                 }
 776         }
 777
 778         free(result);
 779         return NULL;
 780 }
 781
 782 static void jlink_usb_close(jlink_jtag_t *jlink_jtag)
 783 {
 784         usb_close(jlink_jtag->usb_handle);
 785         free(jlink_jtag);
 786 }
 787
 788 /* Send a message and receive the reply. */
 789 static int jlink_usb_message(jlink_jtag_t *jlink_jtag, int out_length, int in_length)
 790 {
 791         int result;
 792         int result2;
 793
 794         result = jlink_usb_write(jlink_jtag, out_length);
 795         if (result == out_length)
 796         {
 797                 result = jlink_usb_read(jlink_jtag, in_length);
 798                 if (result == in_length || result == in_length+1)
 799                 {
 800                         if (result == in_length)
 801                         {
 802                                 /* Must read the result from the EMU too */
 803                                 result2 = jlink_usb_read_emu_result(jlink_jtag);
 804                                 if (1 == result2)
 805                                 {
 806                                         /* Check the result itself */
 807                                         if (0 == usb_emu_result_buffer[0])
 808                                         {
 809                                                 return result;
 810                                         }
 811                                         else
 812                                         {
 813                                                 LOG_ERROR("jlink_usb_read_emu_result (requested=0, result=%d)", usb_emu_result_buffer[0]);
 814                                                 return -1;
 815                                         }
 816                                 }
 817                                 else
 818                                 {
 819                                         LOG_ERROR("jlink_usb_read_emu_result len (requested=1, result=%d)", result2);
 820                                         return -1;
 821                                 }
 822                         }
 823                         else
 824                         {
 825                                 /* Check the result itself */
 826                                 if (0 == usb_in_buffer[result-1])
 827                                 {
 828                                         return result-1;
 829                                 }
 830                                 else
 831                                 {
 832                                         LOG_ERROR("jlink_usb_read_emu_result (requested=0, result=%d)", usb_in_buffer[result]);
 833                                         return -1;
 834                                 }
 835                         }
 836                 }
 837                 else
 838                 {
 839                         LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)", in_length, result);
 840                         return -1;
 841                 }
 842         }
 843         else
 844         {
 845                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)", out_length, result);
 846                 return -1;
 847         }
 848 }
 849
 850 /* calls the given usb_bulk_* function, allowing for the data to trickle in with some timeouts  */
 851 static int usb_bulk_with_retries(
 852                 int (*f)(usb_dev_handle *, int, char *, int, int),
 853                 usb_dev_handle *dev, int ep,
 854                 char *bytes, int size, int timeout)
 855 {
 856         int rc = 0, tries = 3, this_size;
 857
 858         while (tries && size) {
 859
 860                 this_size = f(dev, ep, bytes, size, timeout);
 861                 if (this_size > 0) {
 862
 863                         size -= this_size;
 864                         rc += this_size;
 865                         bytes += this_size;
 866
 867                 } else
 868                         tries --;
 869         }
 870         return rc;
 871 }
 872 static inline int usb_bulk_write_ex(usb_dev_handle *dev, int ep,
 873                 char *bytes, int size, int timeout)
 874 {
 875         return usb_bulk_with_retries(&usb_bulk_write,
 876                         dev, ep, bytes, size, timeout);
 877 }
 878 static inline int usb_bulk_read_ex(usb_dev_handle *dev, int ep,
 879                 char *bytes, int size, int timeout)
 880 {
 881         return usb_bulk_with_retries(&usb_bulk_read,
 882                         dev, ep, bytes, size, timeout);
 883 }
 884
 885 /* Write data from out_buffer to USB. */
 886 static int jlink_usb_write(jlink_jtag_t *jlink_jtag, int out_length)
 887 {
 888         int result;
 889
 890         if (out_length > JLINK_OUT_BUFFER_SIZE)
 891         {
 892                 LOG_ERROR("jlink_jtag_write illegal out_length=%d (max=%d)", out_length, JLINK_OUT_BUFFER_SIZE);
 893                 return -1;
 894         }
 895
 896         result = usb_bulk_write_ex(jlink_jtag->usb_handle, JLINK_WRITE_ENDPOINT,
 897                 (char *)usb_out_buffer, out_length, JLINK_USB_TIMEOUT);
 898
 899         DEBUG_JTAG_IO("jlink_usb_write, out_length = %d, result = %d", out_length, result);
 900
 901 #ifdef _DEBUG_USB_COMMS_
 902         jlink_debug_buffer(usb_out_buffer, out_length);
 903 #endif
 904         return result;
 905 }
 906
 907 /* Read data from USB into in_buffer. */
 908 static int jlink_usb_read(jlink_jtag_t *jlink_jtag, int expected_size)
 909 {
 910         int result = usb_bulk_read_ex(jlink_jtag->usb_handle, JLINK_READ_ENDPOINT,
 911                 (char *)usb_in_buffer, expected_size, JLINK_USB_TIMEOUT);
 912
 913         DEBUG_JTAG_IO("jlink_usb_read, result = %d", result);
 914
 915 #ifdef _DEBUG_USB_COMMS_
 916         jlink_debug_buffer(usb_in_buffer, result);
 917 #endif
 918         return result;
 919 }
 920
 921 /* Read the result from the previous EMU cmd into result_buffer. */
 922 static int jlink_usb_read_emu_result(jlink_jtag_t *jlink_jtag)
 923 {
 924         int result = usb_bulk_read_ex(jlink_jtag->usb_handle, JLINK_READ_ENDPOINT,
 925                 (char *)usb_emu_result_buffer, 1 /* JLINK_EMU_RESULT_BUFFER_SIZE */,
 926                 JLINK_USB_TIMEOUT);
 927
 928         DEBUG_JTAG_IO("jlink_usb_read_result, result = %d", result);
 929
 930 #ifdef _DEBUG_USB_COMMS_
 931         jlink_debug_buffer(usb_emu_result_buffer, result);
 932 #endif
 933         return result;
 934 }
 935
 936 #ifdef _DEBUG_USB_COMMS_
 937 #define BYTES_PER_LINE  16
 938
 939 static void jlink_debug_buffer(u8 *buffer, int length)
 940 {
 941         char line[81];
 942         char s[4];
 943         int i;
 944         int j;
 945
 946         for (i = 0; i < length; i += BYTES_PER_LINE)
 947         {
 948                 snprintf(line, 5, "%04x", i);
 949                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
 950                 {
 951                         snprintf(s, 4, " %02x", buffer[j]);
 952                         strcat(line, s);
 953                 }
 954                 LOG_DEBUG("%s", line);
 955         }
 956 }
 957 #endif