src/jtag/presto.c

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by Pavel Chromy                                    *
   3  *   chromy@asix.cz                                                        *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  19  ***************************************************************************/
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #if IS_CYGWIN == 1
  25 #include "windows.h"
  26 #endif
  27
  28 #include "interface.h"
  29 #include "time_support.h"
  30 #include "bitq.h"
  31
  32
  33 /* PRESTO access library includes */
  34 #if BUILD_PRESTO_FTD2XX == 1
  35 #include <ftd2xx.h>
  36 #elif BUILD_PRESTO_LIBFTDI == 1
  37 #include <ftdi.h>
  38 #else
  39 #error "BUG: either FTD2XX and LIBFTDI has to be used"
  40 #endif
  41
  42 static int presto_jtag_speed(int speed);
  43 static int presto_jtag_khz(int khz, int *jtag_speed);
  44 static int presto_jtag_speed_div(int speed, int *khz);
  45 static int presto_jtag_register_commands(struct command_context *cmd_ctx);
  46 static int presto_jtag_init(void);
  47 static int presto_jtag_quit(void);
  48
  49 struct jtag_interface presto_interface =
  50 {
  51         .name = "presto",
  52         .execute_queue = bitq_execute_queue,
  53         .speed = presto_jtag_speed,
  54         .khz = presto_jtag_khz,
  55         .speed_div = presto_jtag_speed_div,
  56         .register_commands = presto_jtag_register_commands,
  57         .init = presto_jtag_init,
  58         .quit = presto_jtag_quit,
  59 };
  60
  61 static int presto_bitq_out(int tms, int tdi, int tdo_req);
  62 static int presto_bitq_flush(void);
  63 static int presto_bitq_sleep(unsigned long us);
  64 static int presto_bitq_reset(int trst, int srst);
  65 static int presto_bitq_in_rdy(void);
  66 static int presto_bitq_in(void);
  67
  68 static struct bitq_interface presto_bitq =
  69 {
  70         .out = presto_bitq_out,
  71         .flush = presto_bitq_flush,
  72         .sleep = presto_bitq_sleep,
  73         .reset = presto_bitq_reset,
  74         .in_rdy = presto_bitq_in_rdy,
  75         .in = presto_bitq_in,
  76 };
  77
  78 /* -------------------------------------------------------------------------- */
  79
  80 #define FT_DEVICE_NAME_LEN 64
  81 #define FT_DEVICE_SERNUM_LEN 64
  82
  83 #define PRESTO_VID_PID 0x0403f1a0
  84 #define PRESTO_VID (0x0403)
  85 #define PRESTO_PID (0xf1a0)
  86
  87 #define BUFFER_SIZE (64*62)
  88
  89 struct presto {
  90 #if BUILD_PRESTO_FTD2XX == 1
  91         FT_HANDLE handle;
  92         FT_STATUS status;
  93 #elif BUILD_PRESTO_LIBFTDI == 1
  94         struct ftdi_context ftdic;
  95         int retval;
  96 #endif
  97
  98         char serial[FT_DEVICE_SERNUM_LEN];
  99
 100         uint8_t buff_out[BUFFER_SIZE];
 101         int buff_out_pos;
 102
 103         uint8_t buff_in[BUFFER_SIZE];
 104         int buff_in_exp; /* expected in buffer length */
 105         int buff_in_len; /* length of data received */
 106         int buff_in_pos;
 107
 108         unsigned long total_out;
 109         unsigned long total_in;
 110
 111         int jtag_tms; /* last tms state */
 112         int jtag_tck; /* last tck state */
 113         int jtag_rst; /* last trst state */
 114
 115         int jtag_tdi_data;
 116         int jtag_tdi_count;
 117
 118         int jtag_speed;
 119 };
 120
 121 static struct presto presto_state;
 122 static struct presto *presto = &presto_state;
 123
 124 static uint8_t presto_init_seq[] =
 125 {
 126         0x80, 0xA0, 0xA8, 0xB0, 0xC0, 0xE0
 127 };
 128
 129 static int presto_write(uint8_t *buf, uint32_t size)
 130 {
 131 #if BUILD_PRESTO_FTD2XX == 1
 132         DWORD ftbytes;
 133         if ((presto->status = FT_Write(presto->handle, buf, size, &ftbytes)) != FT_OK)
 134         {
 135                 LOG_ERROR("FT_Write returned: %lu", presto->status);
 136                 return ERROR_JTAG_DEVICE_ERROR;
 137         }
 138
 139 #elif BUILD_PRESTO_LIBFTDI == 1
 140         uint32_t ftbytes;
 141         if ((presto->retval = ftdi_write_data(&presto->ftdic, buf, size)) < 0)
 142         {
 143                 LOG_ERROR("ftdi_write_data: %s", ftdi_get_error_string(&presto->ftdic));
 144                 return ERROR_JTAG_DEVICE_ERROR;
 145         }
 146         ftbytes = presto->retval;
 147 #endif
 148
 149         if (ftbytes != size)
 150         {
 151                 LOG_ERROR("couldn't write the requested number of bytes to PRESTO (%u < %u)",
 152                           (unsigned)ftbytes, (unsigned)size);
 153                 return ERROR_JTAG_DEVICE_ERROR;
 154         }
 155
 156         return ERROR_OK;
 157 }
 158
 159 static int presto_read(uint8_t* buf, uint32_t size)
 160 {
 161 #if BUILD_PRESTO_FTD2XX == 1
 162         DWORD ftbytes;
 163         if ((presto->status = FT_Read(presto->handle, buf, size, &ftbytes)) != FT_OK)
 164         {
 165                 LOG_ERROR("FT_Read returned: %lu", presto->status);
 166                 return ERROR_JTAG_DEVICE_ERROR;
 167         }
 168
 169 #elif BUILD_PRESTO_LIBFTDI == 1
 170         uint32_t ftbytes = 0;
 171
 172         struct timeval timeout, now;
 173         gettimeofday(&timeout, NULL);
 174         timeval_add_time(&timeout, 1, 0); /* one second timeout */
 175
 176         while (ftbytes < size)
 177         {
 178                 if ((presto->retval = ftdi_read_data(&presto->ftdic, buf + ftbytes, size - ftbytes)) < 0)
 179                 {
 180                         LOG_ERROR("ftdi_read_data: %s", ftdi_get_error_string(&presto->ftdic));
 181                         return ERROR_JTAG_DEVICE_ERROR;
 182                 }
 183                 ftbytes += presto->retval;
 184
 185                 gettimeofday(&now, NULL);
 186                 if ((now.tv_sec > timeout.tv_sec) || ((now.tv_sec == timeout.tv_sec) && (now.tv_usec > timeout.tv_usec)))
 187                         break;
 188         }
 189 #endif
 190
 191         if (ftbytes != size)
 192         {
 193                 /* this is just a warning, there might have been timeout when detecting PRESTO, which is not fatal */
 194                 LOG_WARNING("couldn't read the requested number of bytes from PRESTO (%u < %u)",
 195                             (unsigned)ftbytes, (unsigned)size);
 196                 return ERROR_JTAG_DEVICE_ERROR;
 197         }
 198
 199         return ERROR_OK;
 200 }
 201
 202 #if BUILD_PRESTO_FTD2XX == 1
 203 static int presto_open_ftd2xx(char *req_serial)
 204 {
 205         uint32_t i;
 206         DWORD numdevs;
 207         DWORD vidpid;
 208         char devname[FT_DEVICE_NAME_LEN];
 209         FT_DEVICE device;
 210
 211         BYTE presto_data;
 212         DWORD ftbytes;
 213
 214         presto->handle = (FT_HANDLE)INVALID_HANDLE_VALUE;
 215
 216 #if IS_WIN32 == 0
 217         /* Add non-standard Vid/Pid to the linux driver */
 218         if ((presto->status = FT_SetVIDPID(PRESTO_VID, PRESTO_PID)) != FT_OK)
 219         {
 220                 LOG_ERROR("couldn't add PRESTO VID/PID");
 221                 exit(-1);
 222         }
 223 #endif
 224
 225         if ((presto->status = FT_ListDevices(&numdevs, NULL, FT_LIST_NUMBER_ONLY)) != FT_OK)
 226         {
 227                 LOG_ERROR("FT_ListDevices failed: %i", (int)presto->status);
 228                 return ERROR_JTAG_DEVICE_ERROR;
 229         }
 230
 231         LOG_DEBUG("FTDI devices available: %lu", numdevs);
 232         for (i = 0; i < numdevs; i++)
 233         {
 234                 if ((presto->status = FT_Open(i, &(presto->handle))) != FT_OK)
 235                 {
 236                         /* this is not fatal, the device may be legitimately open by other process, hence debug message only */
 237                         LOG_DEBUG("FT_Open failed: %i", (int)presto->status);
 238                         continue;
 239                 }
 240                 LOG_DEBUG("FTDI device %i open", (int)i);
 241
 242                 if ((presto->status = FT_GetDeviceInfo(presto->handle, &device, &vidpid,
 243                                 presto->serial, devname, NULL)) == FT_OK)
 244                 {
 245                         if (vidpid == PRESTO_VID_PID
 246                                         && (req_serial == NULL || !strcmp(presto->serial, req_serial)))
 247                                 break;
 248                 }
 249                 else
 250                         LOG_DEBUG("FT_GetDeviceInfo failed: %lu", presto->status);
 251
 252                 LOG_DEBUG("FTDI device %i does not match, closing", (int)i);
 253                 FT_Close(presto->handle);
 254                 presto->handle = (FT_HANDLE)INVALID_HANDLE_VALUE;
 255         }
 256
 257         if (presto->handle == (FT_HANDLE)INVALID_HANDLE_VALUE)
 258                 return ERROR_JTAG_DEVICE_ERROR; /* presto not open, return */
 259
 260         if ((presto->status = FT_SetLatencyTimer(presto->handle, 1)) != FT_OK)
 261                 return ERROR_JTAG_DEVICE_ERROR;
 262
 263
 264         if ((presto->status = FT_SetTimeouts(presto->handle, 100, 0)) != FT_OK)
 265                 return ERROR_JTAG_DEVICE_ERROR;
 266
 267         if ((presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX)) != FT_OK)
 268                 return ERROR_JTAG_DEVICE_ERROR;
 269
 270         presto_data = 0xD0;
 271         if ((presto->status = FT_Write(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 272                 return ERROR_JTAG_DEVICE_ERROR;
 273
 274         /* delay between first write/read turnaround (after purge?) necessary under Linux for unknown reason,
 275            probably a bug in library threading */
 276         usleep(100000);
 277         if ((presto->status = FT_Read(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 278                 return ERROR_JTAG_DEVICE_ERROR;
 279
 280         if (ftbytes != 1)
 281         {
 282                 LOG_DEBUG("PRESTO reset");
 283
 284                 if ((presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX)) != FT_OK)
 285                         return ERROR_JTAG_DEVICE_ERROR;
 286                 if ((presto->status = FT_SetBitMode(presto->handle, 0x80, 1)) != FT_OK)
 287                         return ERROR_JTAG_DEVICE_ERROR;
 288                 if ((presto->status = FT_SetBaudRate(presto->handle, 9600)) != FT_OK)
 289                         return ERROR_JTAG_DEVICE_ERROR;
 290
 291                 presto_data = 0;
 292                 for (i = 0; i < 4 * 62; i++)
 293                         if ((presto->status = FT_Write(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 294                                 return ERROR_JTAG_DEVICE_ERROR;
 295
 296                 usleep(100000);
 297
 298                 if ((presto->status = FT_SetBitMode(presto->handle, 0x00, 0)) != FT_OK)
 299                         return ERROR_JTAG_DEVICE_ERROR;
 300
 301                 if ((presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX)) != FT_OK)
 302                         return ERROR_JTAG_DEVICE_ERROR;
 303
 304                 presto_data = 0xD0;
 305                 if ((presto->status = FT_Write(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 306                         return ERROR_JTAG_DEVICE_ERROR;
 307
 308                 /* delay between first write/read turnaround (after purge?) necessary under Linux for unknown reason,
 309                    probably a bug in library threading */
 310                 usleep(100000);
 311                 if ((presto->status = FT_Read(presto->handle, &presto_data, 1, &ftbytes)) != FT_OK)
 312                         return ERROR_JTAG_DEVICE_ERROR;
 313
 314                 if (ftbytes != 1)
 315                 {
 316                         LOG_DEBUG("PRESTO not responding");
 317                         return ERROR_JTAG_DEVICE_ERROR;
 318                 }
 319         }
 320
 321         if ((presto->status = FT_SetTimeouts(presto->handle, 0, 0)) != FT_OK)
 322                 return ERROR_JTAG_DEVICE_ERROR;
 323
 324
 325         presto->status = FT_Write(presto->handle, &presto_init_seq, sizeof(presto_init_seq), &ftbytes);
 326         if (presto->status != FT_OK || ftbytes != sizeof(presto_init_seq))
 327                 return ERROR_JTAG_DEVICE_ERROR;
 328
 329         return ERROR_OK;
 330 }
 331
 332 #elif BUILD_PRESTO_LIBFTDI == 1
 333 static int presto_open_libftdi(char *req_serial)
 334 {
 335         uint8_t presto_data;
 336
 337         LOG_DEBUG("searching for PRESTO using libftdi");
 338
 339         /* initialize FTDI context structure */
 340         if (ftdi_init(&presto->ftdic) < 0)
 341         {
 342                 LOG_ERROR("unable to init libftdi: %s", presto->ftdic.error_str);
 343                 return ERROR_JTAG_DEVICE_ERROR;
 344         }
 345
 346         /* context, vendor id, product id */
 347         if (ftdi_usb_open_desc(&presto->ftdic, PRESTO_VID, PRESTO_PID, NULL, req_serial) < 0)
 348         {
 349                 LOG_ERROR("unable to open PRESTO: %s", presto->ftdic.error_str);
 350                 return ERROR_JTAG_DEVICE_ERROR;
 351         }
 352
 353         if (ftdi_usb_reset(&presto->ftdic) < 0)
 354         {
 355                 LOG_ERROR("unable to reset PRESTO device");
 356                 return ERROR_JTAG_DEVICE_ERROR;
 357         }
 358
 359         if (ftdi_set_latency_timer(&presto->ftdic, 1) < 0)
 360         {
 361                 LOG_ERROR("unable to set latency timer");
 362                 return ERROR_JTAG_DEVICE_ERROR;
 363         }
 364
 365         if (ftdi_usb_purge_buffers(&presto->ftdic) < 0)
 366         {
 367                 LOG_ERROR("unable to purge PRESTO buffers");
 368                 return ERROR_JTAG_DEVICE_ERROR;
 369         }
 370
 371         presto_data = 0xD0;
 372         if (presto_write(&presto_data, 1) != ERROR_OK)
 373         {
 374                 LOG_ERROR("error writing to PRESTO");
 375                 return ERROR_JTAG_DEVICE_ERROR;
 376         }
 377
 378         if (presto_read(&presto_data, 1) != ERROR_OK)
 379         {
 380                 LOG_DEBUG("no response from PRESTO, retrying");
 381
 382                 if (ftdi_usb_purge_buffers(&presto->ftdic) < 0)
 383                         return ERROR_JTAG_DEVICE_ERROR;
 384
 385                 presto_data = 0xD0;
 386                 if (presto_write(&presto_data, 1) != ERROR_OK)
 387                         return ERROR_JTAG_DEVICE_ERROR;
 388
 389                 if (presto_read(&presto_data, 1) != ERROR_OK)
 390                 {
 391                         LOG_ERROR("no response from PRESTO, giving up");
 392                         return ERROR_JTAG_DEVICE_ERROR;
 393                 }
 394         }
 395
 396         if (presto_write(presto_init_seq, sizeof(presto_init_seq)) != ERROR_OK)
 397         {
 398                 LOG_ERROR("error writing PRESTO init sequence");
 399                 return ERROR_JTAG_DEVICE_ERROR;
 400         }
 401
 402         return ERROR_OK;
 403 }
 404 #endif /* BUILD_PRESTO_LIBFTDI == 1 */
 405
 406 static int presto_open(char *req_serial)
 407 {
 408         presto->buff_out_pos = 0;
 409         presto->buff_in_pos = 0;
 410         presto->buff_in_len = 0;
 411         presto->buff_in_exp = 0;
 412
 413         presto->total_out = 0;
 414         presto->total_in = 0;
 415
 416         presto->jtag_tms = 0;
 417         presto->jtag_tck = 0;
 418         presto->jtag_rst = 0;
 419         presto->jtag_tdi_data = 0;
 420         presto->jtag_tdi_count = 0;
 421
 422         presto->jtag_speed = 0;
 423
 424 #if BUILD_PRESTO_FTD2XX == 1
 425         return presto_open_ftd2xx(req_serial);
 426 #elif BUILD_PRESTO_LIBFTDI == 1
 427         return presto_open_libftdi(req_serial);
 428 #endif
 429 }
 430
 431 static int presto_close(void)
 432 {
 433
 434         int result = ERROR_OK;
 435
 436 #if BUILD_PRESTO_FTD2XX == 1
 437         unsigned long ftbytes;
 438
 439         if (presto->handle == (FT_HANDLE)INVALID_HANDLE_VALUE)
 440                 return result;
 441
 442         presto->status = FT_Purge(presto->handle, FT_PURGE_TX | FT_PURGE_RX);
 443         if (presto->status != FT_OK)
 444                 result = ERROR_JTAG_DEVICE_ERROR;
 445
 446         presto->status = FT_Write(presto->handle, &presto_init_seq, sizeof(presto_init_seq), &ftbytes);
 447         if (presto->status != FT_OK || ftbytes != sizeof(presto_init_seq))
 448                 result = ERROR_JTAG_DEVICE_ERROR;
 449
 450         if ((presto->status = FT_SetLatencyTimer(presto->handle, 16)) != FT_OK)
 451                 result = ERROR_JTAG_DEVICE_ERROR;
 452
 453         if ((presto->status = FT_Close(presto->handle)) != FT_OK)
 454                 result = ERROR_JTAG_DEVICE_ERROR;
 455         else
 456                 presto->handle = (FT_HANDLE)INVALID_HANDLE_VALUE;
 457
 458 #elif BUILD_PRESTO_LIBFTDI == 1
 459
 460         if ((presto->retval = ftdi_write_data(&presto->ftdic, presto_init_seq, sizeof(presto_init_seq))) != sizeof(presto_init_seq))
 461                 result = ERROR_JTAG_DEVICE_ERROR;
 462
 463         if ((presto->retval = ftdi_set_latency_timer(&presto->ftdic, 16)) < 0)
 464                 result = ERROR_JTAG_DEVICE_ERROR;
 465
 466         if ((presto->retval = ftdi_usb_close(&presto->ftdic)) < 0)
 467                 result = ERROR_JTAG_DEVICE_ERROR;
 468         else
 469                 ftdi_deinit(&presto->ftdic);
 470 #endif
 471
 472         return result;
 473 }
 474
 475 static int presto_flush(void)
 476 {
 477         if (presto->buff_out_pos == 0)
 478                 return ERROR_OK;
 479
 480 #if BUILD_PRESTO_FTD2XX == 1
 481         if (presto->status != FT_OK)
 482 #elif BUILD_PRESTO_LIBFTDI == 1
 483         if (presto->retval < 0)
 484 #endif
 485         {
 486                 LOG_DEBUG("error in previous communication, canceling I/O operation");
 487                 return ERROR_JTAG_DEVICE_ERROR;
 488         }
 489
 490         if (presto_write(presto->buff_out, presto->buff_out_pos) != ERROR_OK)
 491         {
 492                 presto->buff_out_pos = 0;
 493                 return ERROR_JTAG_DEVICE_ERROR;
 494         }
 495
 496         presto->total_out += presto->buff_out_pos;
 497         presto->buff_out_pos = 0;
 498
 499         if (presto->buff_in_exp == 0)
 500                 return ERROR_OK;
 501
 502         presto->buff_in_pos = 0;
 503         presto->buff_in_len = 0;
 504
 505         if (presto_read(presto->buff_in, presto->buff_in_exp) != ERROR_OK)
 506         {
 507                 presto->buff_in_exp = 0;
 508                 return ERROR_JTAG_DEVICE_ERROR;
 509         }
 510
 511         presto->total_in += presto->buff_in_exp;
 512         presto->buff_in_len = presto->buff_in_exp;
 513         presto->buff_in_exp = 0;
 514
 515         return ERROR_OK;
 516 }
 517
 518 static int presto_sendbyte(int data)
 519 {
 520         if (data == EOF) return presto_flush();
 521
 522         if (presto->buff_out_pos < BUFFER_SIZE)
 523         {
 524                 presto->buff_out[presto->buff_out_pos++] = (uint8_t)data;
 525                 if (((data & 0xC0) == 0x40) || ((data & 0xD0)== 0xD0))
 526                         presto->buff_in_exp++;
 527         }
 528         else
 529                 return ERROR_JTAG_DEVICE_ERROR;
 530
 531 #if BUILD_PRESTO_FTD2XX == 1
 532         if (presto->buff_out_pos >= BUFFER_SIZE)
 533 #elif BUILD_PRESTO_LIBFTDI == 1
 534         /* libftdi does not do background read, be sure that USB IN buffer does not overflow (128 bytes only!) */
 535         if (presto->buff_out_pos >= BUFFER_SIZE || presto->buff_in_exp == 128)
 536 #endif
 537                 return presto_flush();
 538
 539         return ERROR_OK;
 540 }
 541
 542 #if 0
 543 static int presto_getbyte(void)
 544 {
 545         if (presto->buff_in_pos < presto->buff_in_len)
 546                 return presto->buff_in[presto->buff_in_pos++];
 547
 548         if (presto->buff_in_exp == 0)
 549                 return -1;
 550
 551         if (presto_flush() != ERROR_OK)
 552                 return -1;
 553
 554         if (presto->buff_in_pos < presto->buff_in_len)
 555                 return presto->buff_in[presto->buff_in_pos++];
 556
 557         return -1;
 558 }
 559 #endif
 560
 561 /* -------------------------------------------------------------------------- */
 562
 563 static int presto_tdi_flush(void)
 564 {
 565         if (presto->jtag_tdi_count == 0)
 566                 return 0;
 567
 568         if (presto->jtag_tck == 0)
 569         {
 570                 LOG_ERROR("BUG: unexpected TAP condition, TCK low");
 571                 return -1;
 572         }
 573
 574         presto->jtag_tdi_data |= (presto->jtag_tdi_count - 1) << 4;
 575         presto_sendbyte(presto->jtag_tdi_data);
 576         presto->jtag_tdi_count = 0;
 577         presto->jtag_tdi_data = 0;
 578
 579         return 0;
 580 }
 581
 582 static int presto_tck_idle(void)
 583 {
 584         if (presto->jtag_tck == 1)
 585         {
 586                 presto_sendbyte(0xCA);
 587                 presto->jtag_tck = 0;
 588         }
 589
 590         return 0;
 591 }
 592
 593 /* -------------------------------------------------------------------------- */
 594
 595 static int presto_bitq_out(int tms, int tdi, int tdo_req)
 596 {
 597         int i;
 598         unsigned char cmd;
 599
 600         if (presto->jtag_tck == 0)
 601         {
 602                 presto_sendbyte(0xA4); /* LED idicator - JTAG active */
 603         }
 604         else if (presto->jtag_speed == 0 && !tdo_req && tms == presto->jtag_tms)
 605         {
 606                 presto->jtag_tdi_data |= (tdi != 0) << presto->jtag_tdi_count;
 607
 608                 if (++presto->jtag_tdi_count == 4)
 609                         presto_tdi_flush();
 610
 611                 return 0;
 612         }
 613
 614         presto_tdi_flush();
 615
 616         cmd = tdi ? 0xCB : 0xCA;
 617         presto_sendbyte(cmd);
 618
 619         if (tms != presto->jtag_tms)
 620         {
 621                 presto_sendbyte((tms ? 0xEC : 0xE8) | (presto->jtag_rst ? 0x02 : 0));
 622                 presto->jtag_tms = tms;
 623         }
 624
 625         /* delay with TCK low */
 626         for (i = presto->jtag_speed; i > 1; i--)
 627                 presto_sendbyte(cmd);
 628
 629         cmd |= 0x04;
 630         presto_sendbyte(cmd | (tdo_req ? 0x10 : 0));
 631
 632         /* delay with TCK high */
 633         for (i = presto->jtag_speed; i > 1; i--)
 634                 presto_sendbyte(cmd);
 635
 636         presto->jtag_tck = 1;
 637
 638         return 0;
 639 }
 640
 641 static int presto_bitq_flush(void)
 642 {
 643         presto_tdi_flush();
 644         presto_tck_idle();
 645
 646         presto_sendbyte(0xA0); /* LED idicator - JTAG idle */
 647
 648         return presto_flush();
 649 }
 650
 651 static int presto_bitq_in_rdy(void)
 652 {
 653         if (presto->buff_in_pos >= presto->buff_in_len)
 654                 return 0;
 655         return presto->buff_in_len-presto->buff_in_pos;
 656 }
 657
 658 static int presto_bitq_in(void)
 659 {
 660         if (presto->buff_in_pos >= presto->buff_in_len)
 661                 return -1;
 662         if (presto->buff_in[presto->buff_in_pos++]&0x08) return 1;
 663         return 0;
 664 }
 665
 666 static int presto_bitq_sleep(unsigned long us)
 667 {
 668         long waits;
 669
 670         presto_tdi_flush();
 671         presto_tck_idle();
 672
 673         if (us > 100000)
 674         {
 675                 presto_bitq_flush();
 676                 jtag_sleep(us);
 677                 return 0;
 678         }
 679
 680         waits = us / 170 + 2;
 681         while (waits--)
 682                 presto_sendbyte(0x80);
 683
 684         return 0;
 685 }
 686
 687 static int presto_bitq_reset(int trst, int srst)
 688 {
 689         presto_tdi_flush();
 690         presto_tck_idle();
 691
 692         /* add a delay after possible TCK transition */
 693         presto_sendbyte(0x80);
 694         presto_sendbyte(0x80);
 695
 696         presto->jtag_rst = trst || srst;
 697         presto_sendbyte((presto->jtag_rst ? 0xEA : 0xE8) | (presto->jtag_tms ? 0x04 : 0));
 698
 699         return 0;
 700 }
 701
 702 /* -------------------------------------------------------------------------- */
 703
 704 static int presto_jtag_khz(int khz, int *jtag_speed)
 705 {
 706         if (khz < 0)
 707         {
 708                 *jtag_speed = 0;
 709                 return ERROR_INVALID_ARGUMENTS;
 710         }
 711
 712         if (khz >= 3000) *jtag_speed = 0;
 713         else *jtag_speed = (1000 + khz-1)/khz;
 714
 715         return 0;
 716 }
 717
 718 static int presto_jtag_speed_div(int speed, int *khz)
 719 {
 720         if ((speed < 0) || (speed > 1000))
 721         {
 722                 *khz = 0;
 723                 return ERROR_INVALID_ARGUMENTS;
 724         }
 725
 726         if (speed == 0) *khz = 3000;
 727         else *khz = 1000/speed;
 728
 729         return 0;
 730 }
 731
 732 static int presto_jtag_speed(int speed)
 733 {
 734         int khz;
 735
 736         if (presto_jtag_speed_div(speed, &khz))
 737         {
 738                 return ERROR_INVALID_ARGUMENTS;
 739         }
 740
 741         presto->jtag_speed = speed;
 742
 743         if (khz%1000 == 0)
 744                 LOG_INFO("setting speed to %d, max. TCK freq. is %d MHz", speed, khz/1000);
 745         else
 746                 LOG_INFO("setting speed to %d, max. TCK freq. is %d kHz", speed, khz);
 747
 748         return 0;
 749 }
 750
 751 static char *presto_serial;
 752
 753 COMMAND_HANDLER(presto_handle_serial_command)
 754 {
 755         if (argc == 1)
 756         {
 757                 if (presto_serial)
 758                         free(presto_serial);
 759                 presto_serial = strdup(args[0]);
 760         }
 761         else
 762         {
 763                 LOG_ERROR("expected exactly one argument to presto_serial <serial-number>");
 764         }
 765
 766         return ERROR_OK;
 767 }
 768
 769 static int presto_jtag_register_commands(struct command_context *cmd_ctx)
 770 {
 771         register_command(cmd_ctx, NULL, "presto_serial", presto_handle_serial_command,
 772                 COMMAND_CONFIG, NULL);
 773         return ERROR_OK;
 774 }
 775
 776 static int presto_jtag_init(void)
 777 {
 778         if (presto_open(presto_serial) != ERROR_OK)
 779         {
 780                 presto_close();
 781                 if (presto_serial != NULL)
 782                         LOG_ERROR("Cannot open PRESTO, serial number '%s'", presto_serial);
 783                 else
 784                         LOG_ERROR("Cannot open PRESTO");
 785                 return ERROR_JTAG_INIT_FAILED;
 786         }
 787         LOG_INFO("PRESTO open, serial number '%s'", presto->serial);
 788
 789         /* use JTAG speed setting from configuration file */
 790         presto_jtag_speed(jtag_get_speed());
 791
 792         bitq_interface = &presto_bitq;
 793         return ERROR_OK;
 794 }
 795
 796 static int presto_jtag_quit(void)
 797 {
 798         bitq_cleanup();
 799         presto_close();
 800         LOG_INFO("PRESTO closed");
 801
 802         if (presto_serial)
 803         {
 804                 free(presto_serial);
 805                 presto_serial = NULL;
 806         }
 807
 808         return ERROR_OK;
 809 }