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   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 // See Section 1.3.2 of the Segger JLink USB protocol manual
  46 #define JLINK_IN_BUFFER_SIZE                    2048
  47 #define JLINK_OUT_BUFFER_SIZE                   2048
  48 #define JLINK_EMU_RESULT_BUFFER_SIZE    64
  49
  50 /* Global USB buffers */
  51 static u8 usb_in_buffer[JLINK_IN_BUFFER_SIZE];
  52 static u8 usb_out_buffer[JLINK_OUT_BUFFER_SIZE];
  53 static u8 usb_emu_result_buffer[JLINK_EMU_RESULT_BUFFER_SIZE];
  54
  55 /* Constants for JLink command */
  56 #define EMU_CMD_VERSION     0x01
  57 #define EMU_CMD_SET_SPEED   0x05
  58 #define EMU_CMD_GET_STATE   0x07
  59 #define EMU_CMD_HW_JTAG3    0xcf
  60 #define EMU_CMD_HW_RESET0   0xdc
  61 #define EMU_CMD_HW_RESET1   0xdd
  62 #define EMU_CMD_HW_TRST0    0xde
  63 #define EMU_CMD_HW_TRST1    0xdf
  64
  65 /* max speed 12MHz v5.0 jlink */
  66 #define JLINK_MAX_SPEED 12000
  67
  68 /* External interface functions */
  69 static int jlink_execute_queue(void);
  70 static int jlink_speed(int speed);
  71 static int jlink_speed_div(int speed, int* khz);
  72 static int jlink_khz(int khz, int *jtag_speed);
  73 static int jlink_register_commands(struct command_context_s *cmd_ctx);
  74 static int jlink_init(void);
  75 static int jlink_quit(void);
  76
  77 /* CLI command handler functions */
  78 static int jlink_handle_jlink_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  79
  80 /* Queue command functions */
  81 static void jlink_end_state(tap_state_t state);
  82 static void jlink_state_move(void);
  83 static void jlink_path_move(int num_states, tap_state_t *path);
  84 static void jlink_runtest(int num_cycles);
  85 static void jlink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command);
  86 static void jlink_reset(int trst, int srst);
  87 static void jlink_simple_command(u8 command);
  88 static int jlink_get_status(void);
  89
  90 /* J-Link tap buffer functions */
  91 static void jlink_tap_init(void);
  92 static int jlink_tap_execute(void);
  93 static void jlink_tap_ensure_space(int scans, int bits);
  94 static void jlink_tap_append_step(int tms, int tdi);
  95 static void jlink_tap_append_scan(int length, u8 *buffer, scan_command_t *command);
  96
  97 /* Jlink lowlevel functions */
  98 typedef struct jlink_jtag
  99 {
 100         struct usb_dev_handle* usb_handle;
 101 } jlink_jtag_t;
 102
 103 static jlink_jtag_t *jlink_usb_open(void);
 104 static void jlink_usb_close(jlink_jtag_t *jlink_jtag);
 105 static int jlink_usb_message(jlink_jtag_t *jlink_jtag, int out_length, int in_length);
 106 static int jlink_usb_write(jlink_jtag_t *jlink_jtag, int out_length);
 107 static int jlink_usb_read(jlink_jtag_t *jlink_jtag, int expected_size);
 108 static int jlink_usb_read_emu_result(jlink_jtag_t *jlink_jtag);
 109
 110 /* helper functions */
 111 static int jlink_get_version_info(void);
 112
 113 #ifdef _DEBUG_USB_COMMS_
 114 static void jlink_debug_buffer(u8 *buffer, int length);
 115 #endif
 116
 117 static jlink_jtag_t* jlink_jtag_handle;
 118
 119 /***************************************************************************/
 120 /* External interface implementation */
 121
 122 jtag_interface_t jlink_interface =
 123 {
 124         .name = "jlink",
 125         .execute_queue = jlink_execute_queue,
 126         .speed = jlink_speed,
 127         .speed_div = jlink_speed_div,
 128         .khz = jlink_khz,
 129         .register_commands = jlink_register_commands,
 130         .init = jlink_init,
 131         .quit = jlink_quit
 132 };
 133
 134 static void jlink_execute_end_state(jtag_command_t *cmd)
 135 {
 136         DEBUG_JTAG_IO("end_state: %i", cmd->cmd.end_state->end_state);
 137
 138         if (cmd->cmd.end_state->end_state != TAP_INVALID)
 139                 jlink_end_state(cmd->cmd.end_state->end_state);
 140 }
 141
 142 static void jlink_execute_runtest(jtag_command_t *cmd)
 143 {
 144         DEBUG_JTAG_IO("runtest %i cycles, end in %i",
 145                         cmd->cmd.runtest->num_cycles,
 146                         cmd->cmd.runtest->end_state);
 147
 148         if (cmd->cmd.runtest->end_state != TAP_INVALID)
 149                 jlink_end_state(cmd->cmd.runtest->end_state);
 150
 151         jlink_runtest(cmd->cmd.runtest->num_cycles);
 152 }
 153
 154 static void jlink_execute_statemove(jtag_command_t *cmd)
 155 {
 156         DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 157
 158         if (cmd->cmd.statemove->end_state != TAP_INVALID)
 159         {
 160                 jlink_end_state(cmd->cmd.statemove->end_state);
 161         }
 162         jlink_state_move();
 163 }
 164
 165 static void jlink_execute_pathmove(jtag_command_t *cmd)
 166 {
 167         DEBUG_JTAG_IO("pathmove: %i states, end in %i",
 168                 cmd->cmd.pathmove->num_states,
 169                 cmd->cmd.pathmove->path[cmd->cmd.pathmove->num_states - 1]);
 170
 171         jlink_path_move(cmd->cmd.pathmove->num_states,
 172                         cmd->cmd.pathmove->path);
 173 }
 174
 175 static void jlink_execute_scan(jtag_command_t *cmd)
 176 {
 177         int scan_size;
 178         enum scan_type type;
 179         u8 *buffer;
 180
 181         DEBUG_JTAG_IO("scan end in %i", cmd->cmd.scan->end_state);
 182
 183         if (cmd->cmd.scan->end_state != TAP_INVALID)
 184                 jlink_end_state(cmd->cmd.scan->end_state);
 185
 186         scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 187         DEBUG_JTAG_IO("scan input, length = %d", scan_size);
 188
 189 #ifdef _DEBUG_USB_COMMS_
 190         jlink_debug_buffer(buffer, (scan_size + 7) / 8);
 191 #endif
 192         type = jtag_scan_type(cmd->cmd.scan);
 193         jlink_scan(cmd->cmd.scan->ir_scan,
 194                         type, buffer, scan_size, cmd->cmd.scan);
 195 }
 196
 197 static void jlink_execute_reset(jtag_command_t *cmd)
 198 {
 199         DEBUG_JTAG_IO("reset trst: %i srst %i",
 200                         cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 201
 202         jlink_tap_execute();
 203
 204         if (cmd->cmd.reset->trst == 1)
 205                 tap_set_state(TAP_RESET);
 206
 207         jlink_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 208 }
 209
 210 static void jlink_execute_sleep(jtag_command_t *cmd)
 211 {
 212         DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 213         jlink_tap_execute();
 214         jtag_sleep(cmd->cmd.sleep->us);
 215 }
 216
 217 static void jlink_execute_command(jtag_command_t *cmd)
 218 {
 219         switch (cmd->type)
 220         {
 221         case JTAG_END_STATE: jlink_execute_end_state(cmd); break;
 222         case JTAG_RUNTEST:   jlink_execute_runtest(cmd); break;
 223         case JTAG_STATEMOVE: jlink_execute_statemove(cmd); break;
 224         case JTAG_PATHMOVE:  jlink_execute_pathmove(cmd); break;
 225         case JTAG_SCAN:      jlink_execute_scan(cmd); break;
 226         case JTAG_RESET:     jlink_execute_reset(cmd); break;
 227         case JTAG_SLEEP:     jlink_execute_sleep(cmd); break;
 228         default:
 229                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 230                 exit(-1);
 231         }
 232 }
 233
 234 static int jlink_execute_queue(void)
 235 {
 236         jtag_command_t *cmd = jtag_command_queue;
 237
 238         while (cmd != NULL)
 239         {
 240                 jlink_execute_command(cmd);
 241                 cmd = cmd->next;
 242         }
 243
 244         return jlink_tap_execute();
 245 }
 246
 247 /* Sets speed in kHz. */
 248 static int jlink_speed(int speed)
 249 {
 250         int result;
 251
 252         if (speed > JLINK_MAX_SPEED)
 253         {
 254                 LOG_INFO("Ignoring speed request: %dkHz exceeds %dkHz maximum",
 255                                 speed, JLINK_MAX_SPEED);
 256                 return ERROR_OK;
 257         }
 258
 259         /* check for RTCK setting */
 260         if (speed == 0)
 261                 speed = -1;
 262
 263         usb_out_buffer[0] = EMU_CMD_SET_SPEED;
 264         usb_out_buffer[1] = (speed >> 0) & 0xff;
 265         usb_out_buffer[2] = (speed >> 8) & 0xff;
 266
 267         result = jlink_usb_write(jlink_jtag_handle, 3);
 268         if (result != 3)
 269         {
 270                 LOG_ERROR("J-Link setting speed failed (%d)", result);
 271                 return ERROR_JTAG_DEVICE_ERROR;
 272         }
 273
 274         return ERROR_OK;
 275 }
 276
 277 static int jlink_speed_div(int speed, int* khz)
 278 {
 279         *khz = speed;
 280
 281         return ERROR_OK;
 282 }
 283
 284 static int jlink_khz(int khz, int *jtag_speed)
 285 {
 286         *jtag_speed = khz;
 287
 288         return ERROR_OK;
 289 }
 290
 291 static int jlink_register_commands(struct command_context_s *cmd_ctx)
 292 {
 293         register_command(cmd_ctx, NULL, "jlink_info", jlink_handle_jlink_info_command, COMMAND_EXEC,
 294                 "query jlink info");
 295         return ERROR_OK;
 296 }
 297
 298 static int jlink_init(void)
 299 {
 300         int check_cnt;
 301
 302         jlink_jtag_handle = jlink_usb_open();
 303
 304         if (jlink_jtag_handle == 0)
 305         {
 306                 LOG_ERROR("Cannot find jlink Interface! Please check connection and permissions.");
 307                 return ERROR_JTAG_INIT_FAILED;
 308         }
 309
 310         check_cnt = 0;
 311         while (check_cnt < 3)
 312         {
 313                 if (jlink_get_version_info() == ERROR_OK)
 314                 {
 315                         /* attempt to get status */
 316                         jlink_get_status();
 317                         break;
 318                 }
 319
 320                 check_cnt++;
 321         }
 322
 323         if (check_cnt == 3)
 324         {
 325                 LOG_INFO("J-Link initial read failed, don't worry");
 326         }
 327
 328         LOG_INFO("J-Link JTAG Interface ready");
 329
 330         jlink_reset(0, 0);
 331         jlink_tap_init();
 332
 333         return ERROR_OK;
 334 }
 335
 336 static int jlink_quit(void)
 337 {
 338         jlink_usb_close(jlink_jtag_handle);
 339         return ERROR_OK;
 340 }
 341
 342 /***************************************************************************/
 343 /* Queue command implementations */
 344
 345 static void jlink_end_state(tap_state_t state)
 346 {
 347         if (tap_is_state_stable(state))
 348         {
 349                 tap_set_end_state(state);
 350         }
 351         else
 352         {
 353                 LOG_ERROR("BUG: %i is not a valid end state", state);
 354                 exit(-1);
 355         }
 356 }
 357
 358 /* Goes to the end state. */
 359 static void jlink_state_move(void)
 360 {
 361         int i;
 362         int tms = 0;
 363         u8 tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 364
 365         for (i = 0; i < 7; i++)
 366         {
 367                 tms = (tms_scan >> i) & 1;
 368                 jlink_tap_append_step(tms, 0);
 369         }
 370
 371         tap_set_state(tap_get_end_state());
 372 }
 373
 374 static void jlink_path_move(int num_states, tap_state_t *path)
 375 {
 376         int i;
 377
 378         for (i = 0; i < num_states; i++)
 379         {
 380                 if (path[i] == tap_state_transition(tap_get_state(), false))
 381                 {
 382                         jlink_tap_append_step(0, 0);
 383                 }
 384                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 385                 {
 386                         jlink_tap_append_step(1, 0);
 387                 }
 388                 else
 389                 {
 390                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 391                         exit(-1);
 392                 }
 393
 394                 tap_set_state(path[i]);
 395         }
 396
 397         tap_set_end_state(tap_get_state());
 398 }
 399
 400 static void jlink_runtest(int num_cycles)
 401 {
 402         int i;
 403
 404         tap_state_t saved_end_state = tap_get_end_state();
 405
 406         /* only do a state_move when we're not already in IDLE */
 407         if (tap_get_state() != TAP_IDLE)
 408         {
 409                 jlink_end_state(TAP_IDLE);
 410                 jlink_state_move();
 411         }
 412
 413         /* execute num_cycles */
 414         for (i = 0; i < num_cycles; i++)
 415         {
 416                 jlink_tap_append_step(0, 0);
 417         }
 418
 419         /* finish in end_state */
 420         jlink_end_state(saved_end_state);
 421         if (tap_get_state() != tap_get_end_state())
 422         {
 423                 jlink_state_move();
 424         }
 425 }
 426
 427 static void jlink_scan(int ir_scan, enum scan_type type, u8 *buffer, int scan_size, scan_command_t *command)
 428 {
 429         tap_state_t saved_end_state;
 430
 431         jlink_tap_ensure_space(1, scan_size + 8);
 432
 433         saved_end_state = tap_get_end_state();
 434
 435         /* Move to appropriate scan state */
 436         jlink_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 437
 438         /* Only move if we're not already there */
 439         if (tap_get_state() != tap_get_end_state())
 440                 jlink_state_move();
 441
 442         jlink_end_state(saved_end_state);
 443
 444         /* Scan */
 445         jlink_tap_append_scan(scan_size, buffer, command);
 446
 447         /* We are in Exit1, go to Pause */
 448         jlink_tap_append_step(0, 0);
 449
 450         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 451
 452         if (tap_get_state() != tap_get_end_state())
 453         {
 454                 jlink_state_move();
 455         }
 456 }
 457
 458 static void jlink_reset(int trst, int srst)
 459 {
 460         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 461
 462         /* Signals are active low */
 463         if (srst == 0)
 464         {
 465                 jlink_simple_command(EMU_CMD_HW_RESET1);
 466         }
 467         else if (srst == 1)
 468         {
 469                 jlink_simple_command(EMU_CMD_HW_RESET0);
 470         }
 471
 472         if (trst == 0)
 473         {
 474                 jlink_simple_command(EMU_CMD_HW_TRST1);
 475         }
 476         else if (trst == 1)
 477         {
 478                 jlink_simple_command(EMU_CMD_HW_TRST0);
 479         }
 480 }
 481
 482 static void jlink_simple_command(u8 command)
 483 {
 484         int result;
 485
 486         DEBUG_JTAG_IO("0x%02x", command);
 487
 488         usb_out_buffer[0] = command;
 489         result = jlink_usb_write(jlink_jtag_handle, 1);
 490
 491         if (result != 1)
 492         {
 493                 LOG_ERROR("J-Link command 0x%02x failed (%d)", command, result);
 494         }
 495 }
 496
 497 static int jlink_get_status(void)
 498 {
 499         int result;
 500
 501         jlink_simple_command(EMU_CMD_GET_STATE);
 502
 503         result = jlink_usb_read(jlink_jtag_handle, 8);
 504         if (result != 8)
 505         {
 506                 LOG_ERROR("J-Link command EMU_CMD_GET_STATE failed (%d)\n", result);
 507                 return ERROR_JTAG_DEVICE_ERROR;
 508         }
 509
 510         int vref = usb_in_buffer[0] + (usb_in_buffer[1] << 8);
 511         LOG_INFO("Vref = %d.%d TCK = %d TDI = %d TDO = %d TMS = %d SRST = %d TRST = %d\n", \
 512                 vref / 1000, vref % 1000, \
 513                 usb_in_buffer[2], usb_in_buffer[3], usb_in_buffer[4], \
 514                 usb_in_buffer[5], usb_in_buffer[6], usb_in_buffer[7]);
 515
 516         if (vref < 1500)
 517                 LOG_ERROR("Vref too low. Check Target Power\n");
 518
 519         return ERROR_OK;
 520 }
 521
 522 static int jlink_get_version_info(void)
 523 {
 524         int result;
 525         int len;
 526
 527         /* query hardware version */
 528         jlink_simple_command(EMU_CMD_VERSION);
 529
 530         result = jlink_usb_read(jlink_jtag_handle, 2);
 531         if (2 != result)
 532         {
 533                 LOG_ERROR("J-Link command EMU_CMD_VERSION failed (%d)\n",
 534                                 result);
 535                 return ERROR_JTAG_DEVICE_ERROR;
 536         }
 537
 538         len = buf_get_u32(usb_in_buffer, 0, 16);
 539         result = jlink_usb_read(jlink_jtag_handle, len);
 540         if (result != len)
 541         {
 542                 LOG_ERROR("J-Link command EMU_CMD_VERSION failed (%d)\n",
 543                                 result);
 544                 return ERROR_JTAG_DEVICE_ERROR;
 545         }
 546
 547         usb_in_buffer[result] = 0;
 548         LOG_INFO("%s", (char *)usb_in_buffer);
 549
 550         return ERROR_OK;
 551 }
 552
 553 static int jlink_handle_jlink_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 554 {
 555         if (jlink_get_version_info() == ERROR_OK)
 556         {
 557                 /* attempt to get status */
 558                 jlink_get_status();
 559         }
 560
 561         return ERROR_OK;
 562 }
 563
 564 /***************************************************************************/
 565 /* J-Link tap functions */
 566
 567 /* 2048 is the max value we can use here */
 568 #define JLINK_TAP_BUFFER_SIZE 2048
 569
 570 static unsigned tap_length;
 571 static u8 tms_buffer[JLINK_TAP_BUFFER_SIZE];
 572 static u8 tdi_buffer[JLINK_TAP_BUFFER_SIZE];
 573 static u8 tdo_buffer[JLINK_TAP_BUFFER_SIZE];
 574
 575 typedef struct
 576 {
 577         int first;      /* First bit position in tdo_buffer to read */
 578         int length; /* Number of bits to read */
 579         scan_command_t *command; /* Corresponding scan command */
 580         u8 *buffer;
 581 } pending_scan_result_t;
 582
 583 #define MAX_PENDING_SCAN_RESULTS 256
 584
 585 static int pending_scan_results_length;
 586 static pending_scan_result_t pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 587
 588 static int last_tms;
 589
 590 static void jlink_tap_init(void)
 591 {
 592         tap_length = 0;
 593         pending_scan_results_length = 0;
 594 }
 595
 596 static void jlink_tap_ensure_space(int scans, int bits)
 597 {
 598         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 599         int available_bits = JLINK_TAP_BUFFER_SIZE * 8 - tap_length;
 600
 601         if (scans > available_scans || bits > available_bits)
 602         {
 603                 jlink_tap_execute();
 604         }
 605 }
 606
 607 static void jlink_tap_append_step(int tms, int tdi)
 608 {
 609         last_tms = tms;
 610         int index = tap_length / 8;
 611
 612         if (index >= JLINK_TAP_BUFFER_SIZE)
 613         {
 614                 LOG_ERROR("jlink_tap_append_step: overflow");
 615                 exit(-1);
 616         }
 617
 618         int bit_index = tap_length % 8;
 619         u8 bit = 1 << bit_index;
 620
 621         if (tms)
 622                 tms_buffer[index] |= bit;
 623         else
 624                 tms_buffer[index] &= ~bit;
 625
 626         if (tdi)
 627                 tdi_buffer[index] |= bit;
 628         else
 629                 tdi_buffer[index] &= ~bit;
 630
 631         tap_length++;
 632 }
 633
 634 static void jlink_tap_append_scan(int length, u8 *buffer, scan_command_t *command)
 635 {
 636         pending_scan_result_t *pending_scan_result =
 637                 &pending_scan_results_buffer[pending_scan_results_length];
 638         int i;
 639
 640         pending_scan_result->first = tap_length;
 641         pending_scan_result->length = length;
 642         pending_scan_result->command = command;
 643         pending_scan_result->buffer = buffer;
 644
 645         for (i = 0; i < length; i++)
 646         {
 647                 int tms = i < length - 1 ? 0 : 1;
 648                 int tdi = buffer[i / 8] & (1 << (i % 8));
 649                 jlink_tap_append_step(tms, tdi);
 650         }
 651         pending_scan_results_length++;
 652 }
 653
 654 /* Pad and send a tap sequence to the device, and receive the answer.
 655  * For the purpose of padding we assume that we are in idle or pause state. */
 656 static int jlink_tap_execute(void)
 657 {
 658         int byte_length;
 659         int tms_offset;
 660         int tdi_offset;
 661         int i;
 662         int result;
 663
 664         if (!tap_length)
 665                 return ERROR_OK;
 666
 667         /* Pad last byte so that tap_length is divisible by 8 */
 668         while (tap_length % 8 != 0)
 669         {
 670                 /* More of the last TMS value keeps us in the same state,
 671                  * analogous to free-running JTAG interfaces. */
 672                 jlink_tap_append_step(last_tms, 0);
 673         }
 674
 675         byte_length = tap_length / 8;
 676
 677         usb_out_buffer[0] = EMU_CMD_HW_JTAG3;
 678         usb_out_buffer[1] = 0;
 679         usb_out_buffer[2] = (tap_length >> 0) & 0xff;
 680         usb_out_buffer[3] = (tap_length >> 8) & 0xff;
 681
 682         tms_offset = 4;
 683         for (i = 0; i < byte_length; i++)
 684         {
 685                 usb_out_buffer[tms_offset + i] = tms_buffer[i];
 686         }
 687
 688         tdi_offset = tms_offset + byte_length;
 689         for (i = 0; i < byte_length; i++)
 690         {
 691                 usb_out_buffer[tdi_offset + i] = tdi_buffer[i];
 692         }
 693
 694         result = jlink_usb_message(jlink_jtag_handle, 4 + 2 * byte_length, byte_length);
 695
 696         if (result != byte_length)
 697         {
 698                 LOG_ERROR("jlink_tap_execute, wrong result %d (expected %d)",
 699                                 result, byte_length);
 700                 return ERROR_JTAG_QUEUE_FAILED;
 701         }
 702
 703         for (i = 0; i < byte_length; i++)
 704                 tdo_buffer[i] = usb_in_buffer[i];
 705
 706         for (i = 0; i < pending_scan_results_length; i++)
 707         {
 708                 pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
 709                 u8 *buffer = pending_scan_result->buffer;
 710                 int length = pending_scan_result->length;
 711                 int first = pending_scan_result->first;
 712                 scan_command_t *command = pending_scan_result->command;
 713
 714                 /* Copy to buffer */
 715                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 716
 717                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 718
 719 #ifdef _DEBUG_USB_COMMS_
 720                 jlink_debug_buffer(buffer, byte_length);
 721 #endif
 722
 723                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 724                 {
 725                         jlink_tap_init();
 726                         return ERROR_JTAG_QUEUE_FAILED;
 727                 }
 728
 729                 if (pending_scan_result->buffer != NULL)
 730                 {
 731                         free(pending_scan_result->buffer);
 732                 }
 733         }
 734
 735         jlink_tap_init();
 736
 737         return ERROR_OK;
 738 }
 739
 740 /*****************************************************************************/
 741 /* JLink USB low-level functions */
 742
 743 static jlink_jtag_t* jlink_usb_open()
 744 {
 745         struct usb_bus *busses;
 746         struct usb_bus *bus;
 747         struct usb_device *dev;
 748
 749         jlink_jtag_t *result;
 750
 751         result = (jlink_jtag_t*) malloc(sizeof(jlink_jtag_t));
 752
 753         usb_init();
 754         usb_find_busses();
 755         usb_find_devices();
 756
 757         busses = usb_get_busses();
 758
 759         /* find jlink_jtag device in usb bus */
 760
 761         for (bus = busses; bus; bus = bus->next)
 762         {
 763                 for (dev = bus->devices; dev; dev = dev->next)
 764                 {
 765                         if ((dev->descriptor.idVendor == VID) && (dev->descriptor.idProduct == PID))
 766                         {
 767                                 result->usb_handle = usb_open(dev);
 768
 769                                 /* usb_set_configuration required under win32 */
 770                                 usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
 771                                 usb_claim_interface(result->usb_handle, 0);
 772
 773 #if 0
 774                                 /*
 775                                  * This makes problems under Mac OS X. And is not needed
 776                                  * under Windows. Hopefully this will not break a linux build
 777                                  */
 778                                 usb_set_altinterface(result->usb_handle, 0);
 779 #endif
 780                                 return result;
 781                         }
 782                 }
 783         }
 784
 785         free(result);
 786         return NULL;
 787 }
 788
 789 static void jlink_usb_close(jlink_jtag_t *jlink_jtag)
 790 {
 791         usb_close(jlink_jtag->usb_handle);
 792         free(jlink_jtag);
 793 }
 794
 795 /* Send a message and receive the reply. */
 796 static int jlink_usb_message(jlink_jtag_t *jlink_jtag, int out_length, int in_length)
 797 {
 798         int result;
 799         int result2;
 800
 801         result = jlink_usb_write(jlink_jtag, out_length);
 802         if (result != out_length)
 803         {
 804                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)",
 805                                 out_length, result);
 806                 return ERROR_JTAG_DEVICE_ERROR;
 807         }
 808
 809         result = jlink_usb_read(jlink_jtag, in_length);
 810         if ((result != in_length) && (result != in_length + 1))
 811         {
 812                 LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)",
 813                                 in_length, result);
 814                 return ERROR_JTAG_DEVICE_ERROR;
 815         }
 816
 817         if (result == in_length)
 818         {
 819                 /* Must read the result from the EMU too */
 820                 result2 = jlink_usb_read_emu_result(jlink_jtag);
 821                 if (1 != result2)
 822                 {
 823                         LOG_ERROR("jlink_usb_read_emu_result failed "
 824                                 "(requested=1, result=%d)", result2);
 825                         return ERROR_JTAG_DEVICE_ERROR;
 826                 }
 827
 828                 /* Check the result itself */
 829                 result2 = usb_emu_result_buffer[0];
 830         }
 831         else
 832         {
 833                 /* Save the result, then remove it from return value */
 834                 result2 = usb_in_buffer[result--];
 835         }
 836
 837         if (result2)
 838         {
 839                 LOG_ERROR("jlink_usb_message failed with result=%d)", result2);
 840                 return ERROR_JTAG_DEVICE_ERROR;
 841         }
 842
 843         return result;
 844 }
 845
 846 /* calls the given usb_bulk_* function, allowing for the data to trickle in with some timeouts  */
 847 static int usb_bulk_with_retries(
 848                 int (*f)(usb_dev_handle *, int, char *, int, int),
 849                 usb_dev_handle *dev, int ep,
 850                 char *bytes, int size, int timeout)
 851 {
 852         int rc = 0, tries = 3, this_size;
 853
 854         while (tries && size) {
 855
 856                 this_size = f(dev, ep, bytes, size, timeout);
 857                 if (this_size > 0) {
 858
 859                         size -= this_size;
 860                         rc += this_size;
 861                         bytes += this_size;
 862
 863                 } else
 864                         tries --;
 865         }
 866         return rc;
 867 }
 868 static inline int usb_bulk_write_ex(usb_dev_handle *dev, int ep,
 869                 char *bytes, int size, int timeout)
 870 {
 871         return usb_bulk_with_retries(&usb_bulk_write,
 872                         dev, ep, bytes, size, timeout);
 873 }
 874 static inline int usb_bulk_read_ex(usb_dev_handle *dev, int ep,
 875                 char *bytes, int size, int timeout)
 876 {
 877         return usb_bulk_with_retries(&usb_bulk_read,
 878                         dev, ep, bytes, size, timeout);
 879 }
 880
 881 /* Write data from out_buffer to USB. */
 882 static int jlink_usb_write(jlink_jtag_t *jlink_jtag, int out_length)
 883 {
 884         int result;
 885
 886         if (out_length > JLINK_OUT_BUFFER_SIZE)
 887         {
 888                 LOG_ERROR("jlink_jtag_write illegal out_length=%d (max=%d)", out_length, JLINK_OUT_BUFFER_SIZE);
 889                 return -1;
 890         }
 891
 892         result = usb_bulk_write_ex(jlink_jtag->usb_handle, JLINK_WRITE_ENDPOINT,
 893                 (char *)usb_out_buffer, out_length, JLINK_USB_TIMEOUT);
 894
 895         DEBUG_JTAG_IO("jlink_usb_write, out_length = %d, result = %d", out_length, result);
 896
 897 #ifdef _DEBUG_USB_COMMS_
 898         jlink_debug_buffer(usb_out_buffer, out_length);
 899 #endif
 900         return result;
 901 }
 902
 903 /* Read data from USB into in_buffer. */
 904 static int jlink_usb_read(jlink_jtag_t *jlink_jtag, int expected_size)
 905 {
 906         int result = usb_bulk_read_ex(jlink_jtag->usb_handle, JLINK_READ_ENDPOINT,
 907                 (char *)usb_in_buffer, expected_size, JLINK_USB_TIMEOUT);
 908
 909         DEBUG_JTAG_IO("jlink_usb_read, result = %d", result);
 910
 911 #ifdef _DEBUG_USB_COMMS_
 912         jlink_debug_buffer(usb_in_buffer, result);
 913 #endif
 914         return result;
 915 }
 916
 917 /* Read the result from the previous EMU cmd into result_buffer. */
 918 static int jlink_usb_read_emu_result(jlink_jtag_t *jlink_jtag)
 919 {
 920         int result = usb_bulk_read_ex(jlink_jtag->usb_handle, JLINK_READ_ENDPOINT,
 921                 (char *)usb_emu_result_buffer, 1 /* JLINK_EMU_RESULT_BUFFER_SIZE */,
 922                 JLINK_USB_TIMEOUT);
 923
 924         DEBUG_JTAG_IO("jlink_usb_read_result, result = %d", result);
 925
 926 #ifdef _DEBUG_USB_COMMS_
 927         jlink_debug_buffer(usb_emu_result_buffer, result);
 928 #endif
 929         return result;
 930 }
 931
 932 #ifdef _DEBUG_USB_COMMS_
 933 #define BYTES_PER_LINE  16
 934
 935 static void jlink_debug_buffer(u8 *buffer, int length)
 936 {
 937         char line[81];
 938         char s[4];
 939         int i;
 940         int j;
 941
 942         for (i = 0; i < length; i += BYTES_PER_LINE)
 943         {
 944                 snprintf(line, 5, "%04x", i);
 945                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
 946                 {
 947                         snprintf(s, 4, " %02x", buffer[j]);
 948                         strcat(line, s);
 949                 }
 950                 LOG_DEBUG("%s", line);
 951         }
 952 }
 953 #endif