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 "interface.h"
  29 #include "commands.h"
  30
  31 #include <usb.h>
  32
  33
  34 #define VID 0x1366
  35 #define PID 0x0101
  36
  37 #define JLINK_WRITE_ENDPOINT    0x02
  38 #define JLINK_READ_ENDPOINT             0x81
  39
  40 static unsigned int jlink_write_ep = JLINK_WRITE_ENDPOINT;
  41 static unsigned int jlink_read_ep = JLINK_READ_ENDPOINT;
  42 static unsigned int jlink_hw_jtag_version = 2;
  43
  44 #define JLINK_USB_TIMEOUT               1000
  45
  46 // See Section 1.3.2 of the Segger JLink USB protocol manual
  47 /* 2048 is the max value we can use here */
  48 //#define JLINK_TAP_BUFFER_SIZE 2048
  49 #define JLINK_TAP_BUFFER_SIZE 256
  50 //#define JLINK_TAP_BUFFER_SIZE 384
  51
  52 #define JLINK_IN_BUFFER_SIZE                    2048
  53 #define JLINK_OUT_BUFFER_SIZE                   2*2048 + 4
  54 #define JLINK_EMU_RESULT_BUFFER_SIZE    64
  55
  56 /* Global USB buffers */
  57 static uint8_t usb_in_buffer[JLINK_IN_BUFFER_SIZE];
  58 static uint8_t usb_out_buffer[JLINK_OUT_BUFFER_SIZE];
  59 static uint8_t usb_emu_result_buffer[JLINK_EMU_RESULT_BUFFER_SIZE];
  60
  61 /* Constants for JLink command */
  62 #define EMU_CMD_VERSION         0x01
  63 #define EMU_CMD_SET_SPEED               0x05
  64 #define EMU_CMD_GET_STATE               0x07
  65 #define EMU_CMD_HW_CLOCK                        0xc8
  66 #define EMU_CMD_HW_TMS0                 0xc9
  67 #define EMU_CMD_HW_TMS1                 0xca
  68 #define EMU_CMD_HW_JTAG2                0xce
  69 #define EMU_CMD_HW_JTAG3                0xcf
  70 #define EMU_CMD_GET_MAX_MEM_BLOCK       0xd4
  71 #define EMU_CMD_HW_RESET0               0xdc
  72 #define EMU_CMD_HW_RESET1               0xdd
  73 #define EMU_CMD_HW_TRST0                0xde
  74 #define EMU_CMD_HW_TRST1                0xdf
  75 #define EMU_CMD_GET_CAPS                0xe8
  76 #define EMU_CMD_GET_HW_VERSION  0xf0
  77
  78 /* bits return from EMU_CMD_GET_CAPS */
  79 #define EMU_CAP_GET_HW_VERSION          1
  80 #define EMU_CAP_GET_MAX_BLOCK_SIZE      11
  81
  82 /* max speed 12MHz v5.0 jlink */
  83 #define JLINK_MAX_SPEED 12000
  84
  85 /* External interface functions */
  86 static int jlink_execute_queue(void);
  87 static int jlink_speed(int speed);
  88 static int jlink_speed_div(int speed, int* khz);
  89 static int jlink_khz(int khz, int *jtag_speed);
  90 static int jlink_register_commands(struct command_context_s *cmd_ctx);
  91 static int jlink_init(void);
  92 static int jlink_quit(void);
  93
  94 /* CLI command handler functions */
  95 static int jlink_handle_jlink_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  96 static int jlink_handle_jlink_hw_jtag_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  97
  98 /* Queue command functions */
  99 static void jlink_end_state(tap_state_t state);
 100 static void jlink_state_move(void);
 101 static void jlink_path_move(int num_states, tap_state_t *path);
 102 static void jlink_runtest(int num_cycles);
 103 static void jlink_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command);
 104 static void jlink_reset(int trst, int srst);
 105 static void jlink_simple_command(uint8_t command);
 106 static int jlink_get_status(void);
 107
 108 /* J-Link tap buffer functions */
 109 static void jlink_tap_init(void);
 110 static int jlink_tap_execute(void);
 111 static void jlink_tap_ensure_space(int scans, int bits);
 112 static void jlink_tap_append_step(int tms, int tdi);
 113 static void jlink_tap_append_scan(int length, uint8_t *buffer, scan_command_t *command);
 114
 115 /* Jlink lowlevel functions */
 116 typedef struct jlink_jtag
 117 {
 118         struct usb_dev_handle* usb_handle;
 119 } jlink_jtag_t;
 120
 121 static jlink_jtag_t *jlink_usb_open(void);
 122 static void jlink_usb_close(jlink_jtag_t *jlink_jtag);
 123 static int jlink_usb_message(jlink_jtag_t *jlink_jtag, int out_length, int in_length);
 124 static int jlink_usb_write(jlink_jtag_t *jlink_jtag, int out_length);
 125 static int jlink_usb_read(jlink_jtag_t *jlink_jtag, int expected_size);
 126 static int jlink_usb_read_emu_result(jlink_jtag_t *jlink_jtag);
 127
 128 /* helper functions */
 129 static int jlink_get_version_info(void);
 130
 131 #ifdef _DEBUG_USB_COMMS_
 132 static void jlink_debug_buffer(uint8_t *buffer, int length);
 133 #endif
 134
 135 static enum tap_state jlink_last_state = TAP_RESET;
 136
 137 static jlink_jtag_t* jlink_jtag_handle;
 138
 139 /***************************************************************************/
 140 /* External interface implementation */
 141
 142 jtag_interface_t jlink_interface =
 143 {
 144         .name = "jlink",
 145         .execute_queue = jlink_execute_queue,
 146         .speed = jlink_speed,
 147         .speed_div = jlink_speed_div,
 148         .khz = jlink_khz,
 149         .register_commands = jlink_register_commands,
 150         .init = jlink_init,
 151         .quit = jlink_quit
 152 };
 153
 154 static void jlink_execute_runtest(jtag_command_t *cmd)
 155 {
 156         DEBUG_JTAG_IO("runtest %i cycles, end in %i",
 157                         cmd->cmd.runtest->num_cycles,
 158                         cmd->cmd.runtest->end_state);
 159
 160         jlink_end_state(cmd->cmd.runtest->end_state);
 161
 162         jlink_runtest(cmd->cmd.runtest->num_cycles);
 163 }
 164
 165 static void jlink_execute_statemove(jtag_command_t *cmd)
 166 {
 167         DEBUG_JTAG_IO("statemove end in %i", cmd->cmd.statemove->end_state);
 168
 169         jlink_end_state(cmd->cmd.statemove->end_state);
 170         jlink_state_move();
 171 }
 172
 173 static void jlink_execute_pathmove(jtag_command_t *cmd)
 174 {
 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,
 180                         cmd->cmd.pathmove->path);
 181 }
 182
 183 static void jlink_execute_scan(jtag_command_t *cmd)
 184 {
 185         int scan_size;
 186         enum scan_type type;
 187         uint8_t *buffer;
 188
 189         DEBUG_JTAG_IO("scan end in %s", tap_state_name(cmd->cmd.scan->end_state));
 190
 191         jlink_end_state(cmd->cmd.scan->end_state);
 192
 193         scan_size = jtag_build_buffer(cmd->cmd.scan, &buffer);
 194         DEBUG_JTAG_IO("scan input, length = %d", scan_size);
 195
 196 #ifdef _DEBUG_USB_COMMS_
 197         jlink_debug_buffer(buffer, (scan_size + 7) / 8);
 198 #endif
 199         type = jtag_scan_type(cmd->cmd.scan);
 200         jlink_scan(cmd->cmd.scan->ir_scan,
 201                         type, buffer, scan_size, cmd->cmd.scan);
 202 }
 203
 204 static void jlink_execute_reset(jtag_command_t *cmd)
 205 {
 206         DEBUG_JTAG_IO("reset trst: %i srst %i",
 207                         cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 208
 209         jlink_tap_execute();
 210         jlink_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
 211         jlink_tap_execute();
 212 }
 213
 214 static void jlink_execute_sleep(jtag_command_t *cmd)
 215 {
 216         DEBUG_JTAG_IO("sleep %i", cmd->cmd.sleep->us);
 217         jlink_tap_execute();
 218         jtag_sleep(cmd->cmd.sleep->us);
 219 }
 220
 221 static void jlink_execute_command(jtag_command_t *cmd)
 222 {
 223         switch (cmd->type)
 224         {
 225         case JTAG_RUNTEST:   jlink_execute_runtest(cmd); break;
 226         case JTAG_STATEMOVE: jlink_execute_statemove(cmd); break;
 227         case JTAG_PATHMOVE:  jlink_execute_pathmove(cmd); break;
 228         case JTAG_SCAN:      jlink_execute_scan(cmd); break;
 229         case JTAG_RESET:     jlink_execute_reset(cmd); break;
 230         case JTAG_SLEEP:     jlink_execute_sleep(cmd); break;
 231         default:
 232                 LOG_ERROR("BUG: unknown JTAG command type encountered");
 233                 exit(-1);
 234         }
 235 }
 236
 237 static int jlink_execute_queue(void)
 238 {
 239         jtag_command_t *cmd = jtag_command_queue;
 240
 241         while (cmd != NULL)
 242         {
 243                 jlink_execute_command(cmd);
 244                 cmd = cmd->next;
 245         }
 246
 247         return jlink_tap_execute();
 248 }
 249
 250 /* Sets speed in kHz. */
 251 static int jlink_speed(int speed)
 252 {
 253         int result;
 254
 255         if (speed > JLINK_MAX_SPEED)
 256         {
 257                 LOG_INFO("Ignoring speed request: %dkHz exceeds %dkHz maximum",
 258                                 speed, JLINK_MAX_SPEED);
 259                 return ERROR_OK;
 260         }
 261
 262         /* check for RTCK setting */
 263         if (speed == 0)
 264                 speed = -1;
 265
 266         usb_out_buffer[0] = EMU_CMD_SET_SPEED;
 267         usb_out_buffer[1] = (speed >> 0) & 0xff;
 268         usb_out_buffer[2] = (speed >> 8) & 0xff;
 269
 270         result = jlink_usb_write(jlink_jtag_handle, 3);
 271         if (result != 3)
 272         {
 273                 LOG_ERROR("J-Link setting speed failed (%d)", result);
 274                 return ERROR_JTAG_DEVICE_ERROR;
 275         }
 276
 277         return ERROR_OK;
 278 }
 279
 280 static int jlink_speed_div(int speed, int* khz)
 281 {
 282         *khz = speed;
 283
 284         return ERROR_OK;
 285 }
 286
 287 static int jlink_khz(int khz, int *jtag_speed)
 288 {
 289         *jtag_speed = khz;
 290
 291         return ERROR_OK;
 292 }
 293
 294 static int jlink_register_commands(struct command_context_s *cmd_ctx)
 295 {
 296
 297         register_command(cmd_ctx, NULL, "jlink_info",
 298                 &jlink_handle_jlink_info_command, COMMAND_EXEC,
 299                 "query jlink info");
 300         register_command(cmd_ctx, NULL, "jlink_hw_jtag",
 301                 &jlink_handle_jlink_hw_jtag_command, COMMAND_EXEC,
 302                 "set/get jlink hw jtag command version [2 | 3]");
 303         return ERROR_OK;
 304 }
 305
 306 static int jlink_init(void)
 307 {
 308         int i;
 309
 310         jlink_jtag_handle = jlink_usb_open();
 311
 312         if (jlink_jtag_handle == 0)
 313         {
 314                 LOG_ERROR("Cannot find jlink Interface! Please check connection and permissions.");
 315                 return ERROR_JTAG_INIT_FAILED;
 316         }
 317
 318         /*
 319          *  The next three instructions were added after discovering a problem while using an oscilloscope.  For the V8
 320          *      SAM-ICE dongle (and likely other j-link device variants), the reset line to the target microprocessor was found to
 321          *      cycle only intermittently during emulator startup (even after encountering the downstream reset instruction later
 322          *      in the code).  This was found to create two issues:  1) In general it is a bad practice to not reset a CPU to a known
 323          *      state when starting an emulator and 2) something critical happens inside the dongle when it does the first read
 324          *      following a new USB session.  Keeping the processor in reset during the first read collecting version information
 325          *      seems to prevent errant "J-Link command EMU_CMD_VERSION failed" issues.
 326          */
 327
 328         LOG_INFO("J-Link initialization started / target CPU reset initiated");
 329         jlink_simple_command(EMU_CMD_HW_TRST0);
 330         jlink_simple_command(EMU_CMD_HW_RESET0);
 331         usleep(1000);
 332
 333         jlink_hw_jtag_version = 2;
 334
 335         if (jlink_get_version_info() == ERROR_OK)
 336         {
 337                 /* attempt to get status */
 338                 jlink_get_status();
 339         }
 340
 341         LOG_INFO("J-Link JTAG Interface ready");
 342
 343         jlink_reset(0, 0);
 344         jtag_sleep(3000);
 345         jlink_tap_init();
 346         jlink_speed(jtag_get_speed());
 347
 348         /* v5/6 jlink seems to have an issue if the first tap move
 349          * is not divisible by 8, so we send a TLR on first power up */
 350         for (i = 0; i < 8; i++) {
 351                 jlink_tap_append_step(1, 0);
 352         }
 353         jlink_tap_execute();
 354
 355         return ERROR_OK;
 356 }
 357
 358 static int jlink_quit(void)
 359 {
 360         jlink_usb_close(jlink_jtag_handle);
 361         return ERROR_OK;
 362 }
 363
 364 /***************************************************************************/
 365 /* Queue command implementations */
 366
 367 static void jlink_end_state(tap_state_t state)
 368 {
 369         if (tap_is_state_stable(state))
 370         {
 371                 tap_set_end_state(state);
 372         }
 373         else
 374         {
 375                 LOG_ERROR("BUG: %i is not a valid end state", state);
 376                 exit(-1);
 377         }
 378 }
 379
 380 /* Goes to the end state. */
 381 static void jlink_state_move(void)
 382 {
 383         int i;
 384         int tms = 0;
 385         uint8_t tms_scan = tap_get_tms_path(tap_get_state(), tap_get_end_state());
 386         uint8_t tms_scan_bits = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());
 387
 388         for (i = 0; i < tms_scan_bits; i++)
 389         {
 390                 tms = (tms_scan >> i) & 1;
 391                 jlink_tap_append_step(tms, 0);
 392         }
 393
 394         tap_set_state(tap_get_end_state());
 395 }
 396
 397 static void jlink_path_move(int num_states, tap_state_t *path)
 398 {
 399         int i;
 400
 401         for (i = 0; i < num_states; i++)
 402         {
 403                 if (path[i] == tap_state_transition(tap_get_state(), false))
 404                 {
 405                         jlink_tap_append_step(0, 0);
 406                 }
 407                 else if (path[i] == tap_state_transition(tap_get_state(), true))
 408                 {
 409                         jlink_tap_append_step(1, 0);
 410                 }
 411                 else
 412                 {
 413                         LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(tap_get_state()), tap_state_name(path[i]));
 414                         exit(-1);
 415                 }
 416
 417                 tap_set_state(path[i]);
 418         }
 419
 420         tap_set_end_state(tap_get_state());
 421 }
 422
 423 static void jlink_runtest(int num_cycles)
 424 {
 425         int i;
 426
 427         tap_state_t saved_end_state = tap_get_end_state();
 428
 429         jlink_tap_ensure_space(1,num_cycles + 16);
 430
 431         /* only do a state_move when we're not already in IDLE */
 432         if (tap_get_state() != TAP_IDLE)
 433         {
 434                 jlink_end_state(TAP_IDLE);
 435                 jlink_state_move();
 436 //              num_cycles--;
 437         }
 438
 439         /* execute num_cycles */
 440         for (i = 0; i < num_cycles; i++)
 441         {
 442                 jlink_tap_append_step(0, 0);
 443         }
 444
 445         /* finish in end_state */
 446         jlink_end_state(saved_end_state);
 447         if (tap_get_state() != tap_get_end_state())
 448         {
 449                 jlink_state_move();
 450         }
 451 }
 452
 453 static void jlink_scan(bool ir_scan, enum scan_type type, uint8_t *buffer, int scan_size, scan_command_t *command)
 454 {
 455         tap_state_t saved_end_state;
 456
 457         jlink_tap_ensure_space(1, scan_size + 16);
 458
 459         saved_end_state = tap_get_end_state();
 460
 461         /* Move to appropriate scan state */
 462         jlink_end_state(ir_scan ? TAP_IRSHIFT : TAP_DRSHIFT);
 463
 464         /* Only move if we're not already there */
 465         if (tap_get_state() != tap_get_end_state())
 466                 jlink_state_move();
 467
 468         jlink_end_state(saved_end_state);
 469
 470         /* Scan */
 471         jlink_tap_append_scan(scan_size, buffer, command);
 472
 473         /* We are in Exit1, go to Pause */
 474         jlink_tap_append_step(0, 0);
 475
 476         tap_set_state(ir_scan ? TAP_IRPAUSE : TAP_DRPAUSE);
 477
 478         if (tap_get_state() != tap_get_end_state())
 479         {
 480                 jlink_state_move();
 481         }
 482 }
 483
 484 static void jlink_reset(int trst, int srst)
 485 {
 486         LOG_DEBUG("trst: %i, srst: %i", trst, srst);
 487
 488         /* Signals are active low */
 489         if (srst == 0)
 490         {
 491                 jlink_simple_command(EMU_CMD_HW_RESET1);
 492         }
 493         if (srst == 1)
 494         {
 495                 jlink_simple_command(EMU_CMD_HW_RESET0);
 496         }
 497
 498         if (trst == 1)
 499         {
 500                 jlink_simple_command(EMU_CMD_HW_TRST0);
 501         }
 502         if (trst == 0)
 503         {
 504                 jlink_simple_command(EMU_CMD_HW_TRST1);
 505                 jtag_sleep(5000);
 506                 jlink_end_state(TAP_RESET);
 507                 jlink_state_move();
 508         }
 509 }
 510
 511 static void jlink_simple_command(uint8_t command)
 512 {
 513         int result;
 514
 515         DEBUG_JTAG_IO("0x%02x", command);
 516
 517         usb_out_buffer[0] = command;
 518         result = jlink_usb_write(jlink_jtag_handle, 1);
 519
 520         if (result != 1)
 521         {
 522                 LOG_ERROR("J-Link command 0x%02x failed (%d)", command, result);
 523         }
 524 }
 525
 526 static int jlink_get_status(void)
 527 {
 528         int result;
 529
 530         jlink_simple_command(EMU_CMD_GET_STATE);
 531
 532         result = jlink_usb_read(jlink_jtag_handle, 8);
 533         if (result != 8)
 534         {
 535                 LOG_ERROR("J-Link command EMU_CMD_GET_STATE failed (%d)\n", result);
 536                 return ERROR_JTAG_DEVICE_ERROR;
 537         }
 538
 539         int vref = usb_in_buffer[0] + (usb_in_buffer[1] << 8);
 540         LOG_INFO("Vref = %d.%d TCK = %d TDI = %d TDO = %d TMS = %d SRST = %d TRST = %d\n", \
 541                 vref / 1000, vref % 1000, \
 542                 usb_in_buffer[2], usb_in_buffer[3], usb_in_buffer[4], \
 543                 usb_in_buffer[5], usb_in_buffer[6], usb_in_buffer[7]);
 544
 545         if (vref < 1500)
 546                 LOG_ERROR("Vref too low. Check Target Power\n");
 547
 548         return ERROR_OK;
 549 }
 550
 551 static int jlink_get_version_info(void)
 552 {
 553         int result;
 554         int len;
 555         uint32_t jlink_caps, jlink_max_size;
 556
 557         /* query hardware version */
 558         jlink_simple_command(EMU_CMD_VERSION);
 559
 560         result = jlink_usb_read(jlink_jtag_handle, 2);
 561         if (2 != result)
 562         {
 563                 LOG_ERROR("J-Link command EMU_CMD_VERSION failed (%d)\n", result);
 564                 return ERROR_JTAG_DEVICE_ERROR;
 565         }
 566
 567         len = buf_get_u32(usb_in_buffer, 0, 16);
 568         if (len > JLINK_IN_BUFFER_SIZE)
 569         {
 570                 LOG_ERROR("J-Link command EMU_CMD_VERSION impossible return length 0x%0x", len);
 571                 len = JLINK_IN_BUFFER_SIZE;
 572         }
 573
 574         result = jlink_usb_read(jlink_jtag_handle, len);
 575         if (result != len)
 576         {
 577                 LOG_ERROR("J-Link command EMU_CMD_VERSION failed (%d)\n", result);
 578                 return ERROR_JTAG_DEVICE_ERROR;
 579         }
 580
 581         usb_in_buffer[result] = 0;
 582         LOG_INFO("%s", (char *)usb_in_buffer);
 583
 584         /* query hardware capabilities */
 585         jlink_simple_command(EMU_CMD_GET_CAPS);
 586
 587         result = jlink_usb_read(jlink_jtag_handle, 4);
 588         if (4 != result)
 589         {
 590                 LOG_ERROR("J-Link command EMU_CMD_GET_CAPS failed (%d)\n", result);
 591                 return ERROR_JTAG_DEVICE_ERROR;
 592         }
 593
 594         jlink_caps = buf_get_u32(usb_in_buffer, 0, 32);
 595         LOG_INFO("JLink caps 0x%x", (unsigned)jlink_caps);
 596
 597         if (jlink_caps & (1 << EMU_CAP_GET_HW_VERSION))
 598         {
 599                 /* query hardware version */
 600                 jlink_simple_command(EMU_CMD_GET_HW_VERSION);
 601
 602                 result = jlink_usb_read(jlink_jtag_handle, 4);
 603                 if (4 != result)
 604                 {
 605                         LOG_ERROR("J-Link command EMU_CMD_GET_HW_VERSION failed (%d)\n", result);
 606                         return ERROR_JTAG_DEVICE_ERROR;
 607                 }
 608
 609                 uint32_t jlink_hw_version = buf_get_u32(usb_in_buffer, 0, 32);
 610                 uint32_t major_revision = (jlink_hw_version / 10000) % 100;
 611                 if (major_revision >= 5)
 612                         jlink_hw_jtag_version = 3;
 613
 614                 LOG_INFO("JLink hw version %i", (int)jlink_hw_version);
 615         }
 616
 617         if (jlink_caps & (1 << EMU_CAP_GET_MAX_BLOCK_SIZE))
 618         {
 619                 /* query hardware maximum memory block */
 620                 jlink_simple_command(EMU_CMD_GET_MAX_MEM_BLOCK);
 621
 622                 result = jlink_usb_read(jlink_jtag_handle, 4);
 623                 if (4 != result)
 624                 {
 625                         LOG_ERROR("J-Link command EMU_CMD_GET_MAX_MEM_BLOCK failed (%d)\n", result);
 626                         return ERROR_JTAG_DEVICE_ERROR;
 627                 }
 628
 629                 jlink_max_size = buf_get_u32(usb_in_buffer, 0, 32);
 630                 LOG_INFO("JLink max mem block %i", (int)jlink_max_size);
 631         }
 632
 633         return ERROR_OK;
 634 }
 635
 636 static int jlink_handle_jlink_info_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 637 {
 638         if (jlink_get_version_info() == ERROR_OK)
 639         {
 640                 /* attempt to get status */
 641                 jlink_get_status();
 642         }
 643
 644         return ERROR_OK;
 645 }
 646
 647 static int jlink_handle_jlink_hw_jtag_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 648 {
 649         switch (argc) {
 650         case 0:
 651                 command_print(cmd_ctx, "jlink hw jtag  %i", jlink_hw_jtag_version);
 652                 break;
 653         case 1: {
 654                 int request_version = atoi(args[0]);
 655                 switch (request_version) {
 656                 case 2: case 3:
 657                         jlink_hw_jtag_version = request_version;
 658                         break;
 659                 default:
 660                         return ERROR_COMMAND_SYNTAX_ERROR;
 661                 }
 662                 break;
 663         }
 664         default:
 665                 return ERROR_COMMAND_SYNTAX_ERROR;
 666         }
 667
 668         return ERROR_OK;
 669 }
 670
 671 /***************************************************************************/
 672 /* J-Link tap functions */
 673
 674
 675 static unsigned tap_length = 0;
 676 static uint8_t tms_buffer[JLINK_TAP_BUFFER_SIZE];
 677 static uint8_t tdi_buffer[JLINK_TAP_BUFFER_SIZE];
 678 static uint8_t tdo_buffer[JLINK_TAP_BUFFER_SIZE];
 679
 680 typedef struct
 681 {
 682         int first;      /* First bit position in tdo_buffer to read */
 683         int length; /* Number of bits to read */
 684         scan_command_t *command; /* Corresponding scan command */
 685         uint8_t *buffer;
 686 } pending_scan_result_t;
 687
 688 #define MAX_PENDING_SCAN_RESULTS 256
 689
 690 static int pending_scan_results_length;
 691 static pending_scan_result_t pending_scan_results_buffer[MAX_PENDING_SCAN_RESULTS];
 692
 693 static void jlink_tap_init(void)
 694 {
 695         tap_length = 0;
 696         pending_scan_results_length = 0;
 697 }
 698
 699 static void jlink_tap_ensure_space(int scans, int bits)
 700 {
 701         int available_scans = MAX_PENDING_SCAN_RESULTS - pending_scan_results_length;
 702         int available_bits = JLINK_TAP_BUFFER_SIZE * 8 - tap_length - 32;
 703
 704         if (scans > available_scans || bits > available_bits)
 705         {
 706                 jlink_tap_execute();
 707         }
 708 }
 709
 710 static void jlink_tap_append_step(int tms, int tdi)
 711 {
 712         int index = tap_length / 8;
 713
 714         if (index >= JLINK_TAP_BUFFER_SIZE)
 715         {
 716                 LOG_ERROR("jlink_tap_append_step: overflow");
 717                 *(uint32_t *)0xFFFFFFFF = 0;
 718                 exit(-1);
 719         }
 720
 721         int bit_index = tap_length % 8;
 722         uint8_t bit = 1 << bit_index;
 723
 724         // we do not pad TMS, so be sure to initialize all bits
 725         if (0 == bit_index)
 726         {
 727                 tms_buffer[index] = tdi_buffer[index] = 0;
 728         }
 729
 730         if (tms)
 731                 tms_buffer[index] |= bit;
 732         else
 733                 tms_buffer[index] &= ~bit;
 734
 735         if (tdi)
 736                 tdi_buffer[index] |= bit;
 737         else
 738                 tdi_buffer[index] &= ~bit;
 739
 740         tap_length++;
 741 }
 742
 743 static void jlink_tap_append_scan(int length, uint8_t *buffer, scan_command_t *command)
 744 {
 745         pending_scan_result_t *pending_scan_result =
 746                 &pending_scan_results_buffer[pending_scan_results_length];
 747         int i;
 748
 749         pending_scan_result->first = tap_length;
 750         pending_scan_result->length = length;
 751         pending_scan_result->command = command;
 752         pending_scan_result->buffer = buffer;
 753
 754         for (i = 0; i < length; i++)
 755         {
 756                 int tms = (i < (length - 1)) ? 0 : 1;
 757                 int tdi = (buffer[i / 8] & (1 << (i % 8))) != 0;
 758                 jlink_tap_append_step(tms, tdi);
 759         }
 760         pending_scan_results_length++;
 761 }
 762
 763 /* Pad and send a tap sequence to the device, and receive the answer.
 764  * For the purpose of padding we assume that we are in idle or pause state. */
 765 static int jlink_tap_execute(void)
 766 {
 767         int byte_length;
 768         int i;
 769         int result;
 770
 771         if (!tap_length)
 772                 return ERROR_OK;
 773
 774         /* JLink returns an extra NULL in packet when size of in message is a multiple of 64, creates problems with usb comms */
 775         /* WARNING This will interfere with tap state counting */
 776         while ((TAP_SCAN_BYTES(tap_length)%64) == 0)
 777         {
 778                 jlink_tap_append_step((tap_get_state() == TAP_RESET)?1:0, 0);
 779         }
 780
 781         // number of full bytes (plus one if some would be left over)
 782         byte_length = TAP_SCAN_BYTES(tap_length);
 783
 784         bool use_jtag3 = jlink_hw_jtag_version >= 3;
 785         usb_out_buffer[0] = use_jtag3 ? EMU_CMD_HW_JTAG3 : EMU_CMD_HW_JTAG2;
 786         usb_out_buffer[1] = 0;
 787         usb_out_buffer[2] = (tap_length >> 0) & 0xff;
 788         usb_out_buffer[3] = (tap_length >> 8) & 0xff;
 789         memcpy(usb_out_buffer + 4, tms_buffer, byte_length);
 790         memcpy(usb_out_buffer + 4 + byte_length, tdi_buffer, byte_length);
 791
 792         jlink_last_state = jtag_debug_state_machine(tms_buffer, tdi_buffer,
 793                         tap_length, jlink_last_state);
 794
 795         result = jlink_usb_message(jlink_jtag_handle, 4 + 2 * byte_length, byte_length);
 796         if (result != byte_length)
 797         {
 798                 LOG_ERROR("jlink_tap_execute, wrong result %d (expected %d)", result, byte_length);
 799                 jlink_tap_init();
 800                 return ERROR_JTAG_QUEUE_FAILED;
 801         }
 802
 803         memcpy(tdo_buffer, usb_in_buffer, byte_length);
 804
 805         for (i = 0; i < pending_scan_results_length; i++)
 806         {
 807                 pending_scan_result_t *pending_scan_result = &pending_scan_results_buffer[i];
 808                 uint8_t *buffer = pending_scan_result->buffer;
 809                 int length = pending_scan_result->length;
 810                 int first = pending_scan_result->first;
 811                 scan_command_t *command = pending_scan_result->command;
 812
 813                 /* Copy to buffer */
 814                 buf_set_buf(tdo_buffer, first, buffer, 0, length);
 815
 816                 DEBUG_JTAG_IO("pending scan result, length = %d", length);
 817
 818 #ifdef _DEBUG_USB_COMMS_
 819                 jlink_debug_buffer(buffer, TAP_SCAN_BYTES(length));
 820 #endif
 821
 822                 if (jtag_read_buffer(buffer, command) != ERROR_OK)
 823                 {
 824                         jlink_tap_init();
 825                         return ERROR_JTAG_QUEUE_FAILED;
 826                 }
 827
 828                 if (pending_scan_result->buffer != NULL)
 829                 {
 830                         free(pending_scan_result->buffer);
 831                 }
 832         }
 833
 834         jlink_tap_init();
 835         return ERROR_OK;
 836 }
 837
 838 /*****************************************************************************/
 839 /* JLink USB low-level functions */
 840
 841 static jlink_jtag_t* jlink_usb_open()
 842 {
 843         struct usb_bus *busses;
 844         struct usb_bus *bus;
 845         struct usb_device *dev;
 846
 847         jlink_jtag_t *result;
 848
 849         result = (jlink_jtag_t*) malloc(sizeof(jlink_jtag_t));
 850
 851         usb_init();
 852         usb_find_busses();
 853         usb_find_devices();
 854
 855         busses = usb_get_busses();
 856
 857         /* find jlink_jtag device in usb bus */
 858
 859         for (bus = busses; bus; bus = bus->next)
 860         {
 861                 for (dev = bus->devices; dev; dev = dev->next)
 862                 {
 863                         if ((dev->descriptor.idVendor == VID) && (dev->descriptor.idProduct == PID))
 864                         {
 865                                 result->usb_handle = usb_open(dev);
 866
 867                                 /*
 868                                  *      Some j-link dongles experience intermittent communication issues at startup to varying degrees
 869                                  *      depending on the host operating system.  Troubleshooting this problem all the way back to libusb
 870                                  *      revealed that without a usb reset, the hardware can start in an uncertain state causing a litany
 871                                  *      of annoying problems.  The next step was added to the original code to address this problem.
 872                                  */
 873
 874                                 usb_reset(result->usb_handle);
 875
 876                                 /* usb_set_configuration required under win32 */
 877                                 usb_set_configuration(result->usb_handle, dev->config[0].bConfigurationValue);
 878                                 usb_claim_interface(result->usb_handle, 0);
 879
 880 #if 0
 881                                 /*
 882                                  * This makes problems under Mac OS X. And is not needed
 883                                  * under Windows. Hopefully this will not break a linux build
 884                                  */
 885                                 usb_set_altinterface(result->usb_handle, 0);
 886 #endif
 887                                 struct usb_interface *iface = dev->config->interface;
 888                                 struct usb_interface_descriptor *desc = iface->altsetting;
 889                                 for (int i = 0; i < desc->bNumEndpoints; i++)
 890                                 {
 891                                         uint8_t epnum = desc->endpoint[i].bEndpointAddress;
 892                                         bool is_input = epnum & 0x80;
 893                                         LOG_DEBUG("usb ep %s %02x", is_input ? "in" : "out", epnum);
 894                                         if (is_input)
 895                                                 jlink_read_ep = epnum;
 896                                         else
 897                                                 jlink_write_ep = epnum;
 898                                 }
 899
 900                                 return result;
 901                         }
 902                 }
 903         }
 904
 905         free(result);
 906         return NULL;
 907 }
 908
 909 static void jlink_usb_close(jlink_jtag_t *jlink_jtag)
 910 {
 911         usb_close(jlink_jtag->usb_handle);
 912         free(jlink_jtag);
 913 }
 914
 915 /* Send a message and receive the reply. */
 916 static int jlink_usb_message(jlink_jtag_t *jlink_jtag, int out_length, int in_length)
 917 {
 918         int result;
 919
 920         result = jlink_usb_write(jlink_jtag, out_length);
 921         if (result != out_length)
 922         {
 923                 LOG_ERROR("usb_bulk_write failed (requested=%d, result=%d)",
 924                                 out_length, result);
 925                 return ERROR_JTAG_DEVICE_ERROR;
 926         }
 927
 928         result = jlink_usb_read(jlink_jtag, in_length);
 929         if ((result != in_length) && (result != (in_length + 1)))
 930         {
 931                 LOG_ERROR("usb_bulk_read failed (requested=%d, result=%d)",
 932                                 in_length, result);
 933                 return ERROR_JTAG_DEVICE_ERROR;
 934         }
 935
 936         if (jlink_hw_jtag_version < 3)
 937                 return result;
 938
 939         int result2 = ERROR_OK;
 940         if (result == in_length)
 941         {
 942                 /* Must read the result from the EMU too */
 943                 result2 = jlink_usb_read_emu_result(jlink_jtag);
 944                 if (1 != result2)
 945                 {
 946                         LOG_ERROR("jlink_usb_read_emu_result retried requested = 1, result=%d, in_length=%i", result2,in_length);
 947                         /* Try again once, should only happen if (in_length%64 == 0) */
 948                         result2 = jlink_usb_read_emu_result(jlink_jtag);
 949                         if (1 != result2)
 950                         {
 951                                 LOG_ERROR("jlink_usb_read_emu_result failed "
 952                                         "(requested = 1, result=%d)", result2);
 953                                 return ERROR_JTAG_DEVICE_ERROR;
 954                         }
 955                 }
 956
 957                 /* Check the result itself */
 958                 result2 = usb_emu_result_buffer[0];
 959         }
 960         else
 961         {
 962                 /* Save the result, then remove it from return value */
 963                 result2 = usb_in_buffer[result--];
 964         }
 965
 966         if (result2)
 967         {
 968                 LOG_ERROR("jlink_usb_message failed with result=%d)", result2);
 969                 return ERROR_JTAG_DEVICE_ERROR;
 970         }
 971
 972         return result;
 973 }
 974
 975 /* calls the given usb_bulk_* function, allowing for the data to trickle in with some timeouts  */
 976 static int usb_bulk_with_retries(
 977                 int (*f)(usb_dev_handle *, int, char *, int, int),
 978                 usb_dev_handle *dev, int ep,
 979                 char *bytes, int size, int timeout)
 980 {
 981         int tries = 3, count = 0;
 982
 983         while (tries && (count < size))
 984         {
 985                 int result = f(dev, ep, bytes + count, size - count, timeout);
 986                 if (result > 0)
 987                         count += result;
 988                 else if ((-ETIMEDOUT != result) || !--tries)
 989                         return result;
 990         }
 991         return count;
 992 }
 993
 994 static int wrap_usb_bulk_write(usb_dev_handle *dev, int ep,
 995                                char *buff, int size, int timeout)
 996 {
 997         /* usb_bulk_write() takes const char *buff */
 998         return usb_bulk_write(dev, ep, buff, size, timeout);
 999 }
1000
1001 static inline int usb_bulk_write_ex(usb_dev_handle *dev, int ep,
1002                 char *bytes, int size, int timeout)
1003 {
1004         return usb_bulk_with_retries(&wrap_usb_bulk_write,
1005                         dev, ep, bytes, size, timeout);
1006 }
1007
1008 static inline int usb_bulk_read_ex(usb_dev_handle *dev, int ep,
1009                 char *bytes, int size, int timeout)
1010 {
1011         return usb_bulk_with_retries(&usb_bulk_read,
1012                         dev, ep, bytes, size, timeout);
1013 }
1014
1015 /* Write data from out_buffer to USB. */
1016 static int jlink_usb_write(jlink_jtag_t *jlink_jtag, int out_length)
1017 {
1018         int result;
1019
1020         if (out_length > JLINK_OUT_BUFFER_SIZE)
1021         {
1022                 LOG_ERROR("jlink_jtag_write illegal out_length=%d (max=%d)", out_length, JLINK_OUT_BUFFER_SIZE);
1023                 return -1;
1024         }
1025
1026         result = usb_bulk_write_ex(jlink_jtag->usb_handle, jlink_write_ep,
1027                 (char *)usb_out_buffer, out_length, JLINK_USB_TIMEOUT);
1028
1029         DEBUG_JTAG_IO("jlink_usb_write, out_length = %d, result = %d", out_length, result);
1030
1031 #ifdef _DEBUG_USB_COMMS_
1032         jlink_debug_buffer(usb_out_buffer, out_length);
1033 #endif
1034         return result;
1035 }
1036
1037 /* Read data from USB into in_buffer. */
1038 static int jlink_usb_read(jlink_jtag_t *jlink_jtag, int expected_size)
1039 {
1040         int result = usb_bulk_read_ex(jlink_jtag->usb_handle, jlink_read_ep,
1041                 (char *)usb_in_buffer, expected_size, JLINK_USB_TIMEOUT);
1042
1043         DEBUG_JTAG_IO("jlink_usb_read, result = %d", result);
1044
1045 #ifdef _DEBUG_USB_COMMS_
1046         jlink_debug_buffer(usb_in_buffer, result);
1047 #endif
1048         return result;
1049 }
1050
1051 /* Read the result from the previous EMU cmd into result_buffer. */
1052 static int jlink_usb_read_emu_result(jlink_jtag_t *jlink_jtag)
1053 {
1054         int result = usb_bulk_read_ex(jlink_jtag->usb_handle, jlink_read_ep,
1055                 (char *)usb_emu_result_buffer, 1 /* JLINK_EMU_RESULT_BUFFER_SIZE */,
1056                 JLINK_USB_TIMEOUT);
1057
1058         DEBUG_JTAG_IO("jlink_usb_read_result, result = %d", result);
1059
1060 #ifdef _DEBUG_USB_COMMS_
1061         jlink_debug_buffer(usb_emu_result_buffer, result);
1062 #endif
1063         return result;
1064 }
1065
1066 #ifdef _DEBUG_USB_COMMS_
1067 #define BYTES_PER_LINE  16
1068
1069 static void jlink_debug_buffer(uint8_t *buffer, int length)
1070 {
1071         char line[81];
1072         char s[4];
1073         int i;
1074         int j;
1075
1076         for (i = 0; i < length; i += BYTES_PER_LINE)
1077         {
1078                 snprintf(line, 5, "%04x", i);
1079                 for (j = i; j < i + BYTES_PER_LINE && j < length; j++)
1080                 {
1081                         snprintf(s, 4, " %02x", buffer[j]);
1082                         strcat(line, s);
1083                 }
1084                 LOG_DEBUG("%s", line);
1085         }
1086 }
1087 #endif
1088