ISPProtocol.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2018.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2018  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Function ISPProtocol_Calibrate() copyright 2018 Jacob September
  13
  14   Permission to use, copy, modify, distribute, and sell this
  15   software and its documentation for any purpose is hereby granted
  16   without fee, provided that the above copyright notice appear in
  17   all copies and that both that the copyright notice and this
  18   permission notice and warranty disclaimer appear in supporting
  19   documentation, and that the name of the author not be used in
  20   advertising or publicity pertaining to distribution of the
  21   software without specific, written prior permission.
  22
  23   The author disclaims all warranties with regard to this
  24   software, including all implied warranties of merchantability
  25   and fitness.  In no event shall the author be liable for any
  26   special, indirect or consequential damages or any damages
  27   whatsoever resulting from loss of use, data or profits, whether
  28   in an action of contract, negligence or other tortious action,
  29   arising out of or in connection with the use or performance of
  30   this software.
  31 */
  32
  33 /** \file
  34  *
  35  *  ISP Protocol handler, to process V2 Protocol wrapped ISP commands used in Atmel programmer devices.
  36  */
  37
  38 #include "ISPProtocol.h"
  39 #include <util/atomic.h>
  40
  41 #if defined(ENABLE_ISP_PROTOCOL) || defined(__DOXYGEN__)
  42
  43 /** Handler for the CMD_ENTER_PROGMODE_ISP command, which attempts to enter programming mode on
  44  *  the attached device, returning success or failure back to the host.
  45  */
  46 void ISPProtocol_EnterISPMode(void)
  47 {
  48         struct
  49         {
  50                 uint8_t TimeoutMS;
  51                 uint8_t PinStabDelayMS;
  52                 uint8_t ExecutionDelayMS;
  53                 uint8_t SynchLoops;
  54                 uint8_t ByteDelay;
  55                 uint8_t PollValue;
  56                 uint8_t PollIndex;
  57                 uint8_t EnterProgBytes[4];
  58         } Enter_ISP_Params;
  59
  60         Endpoint_Read_Stream_LE(&Enter_ISP_Params, sizeof(Enter_ISP_Params), NULL);
  61
  62         Endpoint_ClearOUT();
  63         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
  64         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
  65
  66         uint8_t ResponseStatus = STATUS_CMD_FAILED;
  67
  68         CurrentAddress = 0;
  69
  70         /* Perform execution delay, initialize SPI bus */
  71         ISPProtocol_DelayMS(Enter_ISP_Params.ExecutionDelayMS);
  72         ISPTarget_EnableTargetISP();
  73
  74         ISPTarget_ChangeTargetResetLine(true);
  75         ISPProtocol_DelayMS(Enter_ISP_Params.PinStabDelayMS);
  76
  77         /* Continuously attempt to synchronize with the target until either the number of attempts specified
  78          * by the host has exceeded, or the the device sends back the expected response values */
  79         while (Enter_ISP_Params.SynchLoops-- && TimeoutTicksRemaining)
  80         {
  81                 uint8_t ResponseBytes[4];
  82
  83                 for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)
  84                 {
  85                         ISPProtocol_DelayMS(Enter_ISP_Params.ByteDelay);
  86                         ResponseBytes[RByte] = ISPTarget_TransferByte(Enter_ISP_Params.EnterProgBytes[RByte]);
  87                 }
  88
  89                 /* Check if polling disabled, or if the polled value matches the expected value */
  90                 if (!(Enter_ISP_Params.PollIndex) || (ResponseBytes[Enter_ISP_Params.PollIndex - 1] == Enter_ISP_Params.PollValue))
  91                 {
  92                         ResponseStatus = STATUS_CMD_OK;
  93                         break;
  94                 }
  95                 else
  96                 {
  97                         ISPTarget_ChangeTargetResetLine(false);
  98                         ISPProtocol_DelayMS(Enter_ISP_Params.PinStabDelayMS);
  99                         ISPTarget_ChangeTargetResetLine(true);
 100                         ISPProtocol_DelayMS(Enter_ISP_Params.PinStabDelayMS);
 101                 }
 102         }
 103
 104         Endpoint_Write_8(CMD_ENTER_PROGMODE_ISP);
 105         Endpoint_Write_8(ResponseStatus);
 106         Endpoint_ClearIN();
 107 }
 108
 109 /** Handler for the CMD_LEAVE_ISP command, which releases the target from programming mode. */
 110 void ISPProtocol_LeaveISPMode(void)
 111 {
 112         struct
 113         {
 114                 uint8_t PreDelayMS;
 115                 uint8_t PostDelayMS;
 116         } Leave_ISP_Params;
 117
 118         Endpoint_Read_Stream_LE(&Leave_ISP_Params, sizeof(Leave_ISP_Params), NULL);
 119
 120         Endpoint_ClearOUT();
 121         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 122         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 123
 124         /* Perform pre-exit delay, release the target /RESET, disable the SPI bus and perform the post-exit delay */
 125         ISPProtocol_DelayMS(Leave_ISP_Params.PreDelayMS);
 126         ISPTarget_ChangeTargetResetLine(false);
 127         ISPTarget_DisableTargetISP();
 128         ISPProtocol_DelayMS(Leave_ISP_Params.PostDelayMS);
 129
 130         Endpoint_Write_8(CMD_LEAVE_PROGMODE_ISP);
 131         Endpoint_Write_8(STATUS_CMD_OK);
 132         Endpoint_ClearIN();
 133 }
 134
 135 /** Handler for the CMD_PROGRAM_FLASH_ISP and CMD_PROGRAM_EEPROM_ISP commands, writing out bytes,
 136  *  words or pages of data to the attached device.
 137  *
 138  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 139  */
 140 void ISPProtocol_ProgramMemory(uint8_t V2Command)
 141 {
 142         struct
 143         {
 144                 uint16_t BytesToWrite;
 145                 uint8_t  ProgrammingMode;
 146                 uint8_t  DelayMS;
 147                 uint8_t  ProgrammingCommands[3];
 148                 uint8_t  PollValue1;
 149                 uint8_t  PollValue2;
 150                 uint8_t  ProgData[256]; // Note, the Jungo driver has a very short ACK timeout period, need to buffer the
 151         } Write_Memory_Params;      // whole page and ACK the packet as fast as possible to prevent it from aborting
 152
 153         Endpoint_Read_Stream_LE(&Write_Memory_Params, (sizeof(Write_Memory_Params) -
 154                                                        sizeof(Write_Memory_Params.ProgData)), NULL);
 155         Write_Memory_Params.BytesToWrite = SwapEndian_16(Write_Memory_Params.BytesToWrite);
 156
 157         if (Write_Memory_Params.BytesToWrite > sizeof(Write_Memory_Params.ProgData))
 158         {
 159                 Endpoint_ClearOUT();
 160                 Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 161                 Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 162
 163                 Endpoint_Write_8(V2Command);
 164                 Endpoint_Write_8(STATUS_CMD_FAILED);
 165                 Endpoint_ClearIN();
 166                 return;
 167         }
 168
 169         Endpoint_Read_Stream_LE(&Write_Memory_Params.ProgData, Write_Memory_Params.BytesToWrite, NULL);
 170
 171         // The driver will terminate transfers that are a round multiple of the endpoint bank in size with a ZLP, need
 172         // to catch this and discard it before continuing on with packet processing to prevent communication issues
 173         if (((sizeof(uint8_t) + sizeof(Write_Memory_Params) - sizeof(Write_Memory_Params.ProgData)) +
 174             Write_Memory_Params.BytesToWrite) % AVRISP_DATA_EPSIZE == 0)
 175         {
 176                 Endpoint_ClearOUT();
 177                 Endpoint_WaitUntilReady();
 178         }
 179
 180         Endpoint_ClearOUT();
 181         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 182         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 183
 184         uint8_t  ProgrammingStatus = STATUS_CMD_OK;
 185         uint8_t  PollValue         = (V2Command == CMD_PROGRAM_FLASH_ISP) ? Write_Memory_Params.PollValue1 :
 186                                                                             Write_Memory_Params.PollValue2;
 187         uint16_t PollAddress       = 0;
 188         uint8_t* NextWriteByte     = Write_Memory_Params.ProgData;
 189         uint16_t PageStartAddress  = (CurrentAddress & 0xFFFF);
 190
 191         for (uint16_t CurrentByte = 0; CurrentByte < Write_Memory_Params.BytesToWrite; CurrentByte++)
 192         {
 193                 uint8_t ByteToWrite     = *(NextWriteByte++);
 194                 uint8_t ProgrammingMode = Write_Memory_Params.ProgrammingMode;
 195
 196                 /* Check to see if we need to send a LOAD EXTENDED ADDRESS command to the target */
 197                 if (MustLoadExtendedAddress)
 198                 {
 199                         ISPTarget_LoadExtendedAddress();
 200                         MustLoadExtendedAddress = false;
 201                 }
 202
 203                 ISPTarget_SendByte(Write_Memory_Params.ProgrammingCommands[0]);
 204                 ISPTarget_SendByte(CurrentAddress >> 8);
 205                 ISPTarget_SendByte(CurrentAddress & 0xFF);
 206                 ISPTarget_SendByte(ByteToWrite);
 207
 208                 /* AVR FLASH addressing requires us to modify the write command based on if we are writing a high
 209                  * or low byte at the current word address */
 210                 if (V2Command == CMD_PROGRAM_FLASH_ISP)
 211                   Write_Memory_Params.ProgrammingCommands[0] ^= READ_WRITE_HIGH_BYTE_MASK;
 212
 213                 /* Check to see if we have a valid polling address */
 214                 if (!(PollAddress) && (ByteToWrite != PollValue))
 215                 {
 216                         if ((CurrentByte & 0x01) && (V2Command == CMD_PROGRAM_FLASH_ISP))
 217                           Write_Memory_Params.ProgrammingCommands[2] |=  READ_WRITE_HIGH_BYTE_MASK;
 218                         else
 219                           Write_Memory_Params.ProgrammingCommands[2] &= ~READ_WRITE_HIGH_BYTE_MASK;
 220
 221                         PollAddress = (CurrentAddress & 0xFFFF);
 222                 }
 223
 224                 /* If in word programming mode, commit the byte to the target's memory */
 225                 if (!(ProgrammingMode & PROG_MODE_PAGED_WRITES_MASK))
 226                 {
 227                         /* If the current polling address is invalid, switch to timed delay write completion mode */
 228                         if (!(PollAddress) && !(ProgrammingMode & PROG_MODE_WORD_READYBUSY_MASK))
 229                           ProgrammingMode = (ProgrammingMode & ~PROG_MODE_WORD_VALUE_MASK) | PROG_MODE_WORD_TIMEDELAY_MASK;
 230
 231                         ProgrammingStatus = ISPTarget_WaitForProgComplete(ProgrammingMode, PollAddress, PollValue,
 232                                                                           Write_Memory_Params.DelayMS,
 233                                                                           Write_Memory_Params.ProgrammingCommands[2]);
 234
 235                         /* Abort the programming loop early if the byte/word programming failed */
 236                         if (ProgrammingStatus != STATUS_CMD_OK)
 237                           break;
 238
 239                         /* Must reset the polling address afterwards, so it is not erroneously used for the next byte */
 240                         PollAddress = 0;
 241                 }
 242
 243                 /* EEPROM just increments the address each byte, flash needs to increment on each word and
 244                  * also check to ensure that a LOAD EXTENDED ADDRESS command is issued each time the extended
 245                  * address boundary has been crossed during FLASH memory programming */
 246                 if ((CurrentByte & 0x01) || (V2Command == CMD_PROGRAM_EEPROM_ISP))
 247                 {
 248                         CurrentAddress++;
 249
 250                         if ((V2Command == CMD_PROGRAM_FLASH_ISP) && !(CurrentAddress & 0xFFFF))
 251                           MustLoadExtendedAddress = true;
 252                 }
 253         }
 254
 255         /* If the current page must be committed, send the PROGRAM PAGE command to the target */
 256         if (Write_Memory_Params.ProgrammingMode & PROG_MODE_COMMIT_PAGE_MASK)
 257         {
 258                 ISPTarget_SendByte(Write_Memory_Params.ProgrammingCommands[1]);
 259                 ISPTarget_SendByte(PageStartAddress >> 8);
 260                 ISPTarget_SendByte(PageStartAddress & 0xFF);
 261                 ISPTarget_SendByte(0x00);
 262
 263                 /* Check if polling is enabled and possible, if not switch to timed delay mode */
 264                 if ((Write_Memory_Params.ProgrammingMode & PROG_MODE_PAGED_VALUE_MASK) && !(PollAddress))
 265                 {
 266                         Write_Memory_Params.ProgrammingMode = (Write_Memory_Params.ProgrammingMode & ~PROG_MODE_PAGED_VALUE_MASK) |
 267                                                                                                    PROG_MODE_PAGED_TIMEDELAY_MASK;
 268                 }
 269
 270                 ProgrammingStatus = ISPTarget_WaitForProgComplete(Write_Memory_Params.ProgrammingMode, PollAddress, PollValue,
 271                                                                   Write_Memory_Params.DelayMS,
 272                                                                   Write_Memory_Params.ProgrammingCommands[2]);
 273
 274                 /* Check to see if the FLASH address has crossed the extended address boundary */
 275                 if ((V2Command == CMD_PROGRAM_FLASH_ISP) && !(CurrentAddress & 0xFFFF))
 276                   MustLoadExtendedAddress = true;
 277         }
 278
 279         Endpoint_Write_8(V2Command);
 280         Endpoint_Write_8(ProgrammingStatus);
 281         Endpoint_ClearIN();
 282 }
 283
 284 /** Handler for the CMD_READ_FLASH_ISP and CMD_READ_EEPROM_ISP commands, reading in bytes,
 285  *  words or pages of data from the attached device.
 286  *
 287  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 288  */
 289 void ISPProtocol_ReadMemory(uint8_t V2Command)
 290 {
 291         struct
 292         {
 293                 uint16_t BytesToRead;
 294                 uint8_t  ReadMemoryCommand;
 295         } Read_Memory_Params;
 296
 297         Endpoint_Read_Stream_LE(&Read_Memory_Params, sizeof(Read_Memory_Params), NULL);
 298         Read_Memory_Params.BytesToRead = SwapEndian_16(Read_Memory_Params.BytesToRead);
 299
 300         Endpoint_ClearOUT();
 301         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 302         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 303
 304         Endpoint_Write_8(V2Command);
 305         Endpoint_Write_8(STATUS_CMD_OK);
 306
 307         /* Read each byte from the device and write them to the packet for the host */
 308         for (uint16_t CurrentByte = 0; CurrentByte < Read_Memory_Params.BytesToRead; CurrentByte++)
 309         {
 310                 /* Check to see if we need to send a LOAD EXTENDED ADDRESS command to the target */
 311                 if (MustLoadExtendedAddress)
 312                 {
 313                         ISPTarget_LoadExtendedAddress();
 314                         MustLoadExtendedAddress = false;
 315                 }
 316
 317                 /* Read the next byte from the desired memory space in the device */
 318                 ISPTarget_SendByte(Read_Memory_Params.ReadMemoryCommand);
 319                 ISPTarget_SendByte(CurrentAddress >> 8);
 320                 ISPTarget_SendByte(CurrentAddress & 0xFF);
 321                 Endpoint_Write_8(ISPTarget_ReceiveByte());
 322
 323                 /* Check if the endpoint bank is currently full, if so send the packet */
 324                 if (!(Endpoint_IsReadWriteAllowed()))
 325                 {
 326                         Endpoint_ClearIN();
 327                         Endpoint_WaitUntilReady();
 328                 }
 329
 330                 /* AVR FLASH addressing requires us to modify the read command based on if we are reading a high
 331                  * or low byte at the current word address */
 332                 if (V2Command == CMD_READ_FLASH_ISP)
 333                   Read_Memory_Params.ReadMemoryCommand ^= READ_WRITE_HIGH_BYTE_MASK;
 334
 335                 /* EEPROM just increments the address each byte, flash needs to increment on each word and
 336                  * also check to ensure that a LOAD EXTENDED ADDRESS command is issued each time the extended
 337                  * address boundary has been crossed */
 338                 if ((CurrentByte & 0x01) || (V2Command == CMD_READ_EEPROM_ISP))
 339                 {
 340                         CurrentAddress++;
 341
 342                         if ((V2Command != CMD_READ_EEPROM_ISP) && !(CurrentAddress & 0xFFFF))
 343                           MustLoadExtendedAddress = true;
 344                 }
 345         }
 346
 347         Endpoint_Write_8(STATUS_CMD_OK);
 348
 349         bool IsEndpointFull = !(Endpoint_IsReadWriteAllowed());
 350         Endpoint_ClearIN();
 351
 352         /* Ensure last packet is a short packet to terminate the transfer */
 353         if (IsEndpointFull)
 354         {
 355                 Endpoint_WaitUntilReady();
 356                 Endpoint_ClearIN();
 357                 Endpoint_WaitUntilReady();
 358         }
 359 }
 360
 361 /** Handler for the CMD_CHI_ERASE_ISP command, clearing the target's FLASH memory. */
 362 void ISPProtocol_ChipErase(void)
 363 {
 364         struct
 365         {
 366                 uint8_t EraseDelayMS;
 367                 uint8_t PollMethod;
 368                 uint8_t EraseCommandBytes[4];
 369         } Erase_Chip_Params;
 370
 371         Endpoint_Read_Stream_LE(&Erase_Chip_Params, sizeof(Erase_Chip_Params), NULL);
 372
 373         Endpoint_ClearOUT();
 374         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 375         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 376
 377         uint8_t ResponseStatus = STATUS_CMD_OK;
 378
 379         /* Send the chip erase commands as given by the host to the device */
 380         for (uint8_t SByte = 0; SByte < sizeof(Erase_Chip_Params.EraseCommandBytes); SByte++)
 381           ISPTarget_SendByte(Erase_Chip_Params.EraseCommandBytes[SByte]);
 382
 383         /* Use appropriate command completion check as given by the host (delay or busy polling) */
 384         if (!(Erase_Chip_Params.PollMethod))
 385           ISPProtocol_DelayMS(Erase_Chip_Params.EraseDelayMS);
 386         else
 387           ResponseStatus = ISPTarget_WaitWhileTargetBusy();
 388
 389         Endpoint_Write_8(CMD_CHIP_ERASE_ISP);
 390         Endpoint_Write_8(ResponseStatus);
 391         Endpoint_ClearIN();
 392 }
 393
 394 /** Global volatile variables used in ISRs relating to ISPProtocol_Calibrate() */
 395 volatile uint16_t HalfCyclesRemaining;
 396 volatile uint8_t  ResponseTogglesRemaining;
 397
 398 /** ISR to toggle MOSI pin when TIMER1 overflows */
 399 ISR(TIMER1_OVF_vect, ISR_BLOCK)
 400 {
 401         PINB |= (1 << PB2);     // toggle PB2 (MOSI) by writing 1 to its bit in PINB
 402         HalfCyclesRemaining--;
 403 }
 404
 405 /** ISR to listen for toggles on MISO pin */
 406 ISR(PCINT0_vect, ISR_BLOCK)
 407 {
 408         ResponseTogglesRemaining--;
 409 }
 410
 411 /** Handler for the CMD_OSCCAL command, entering RC-calibration mode as specified in AVR053 */
 412 void ISPProtocol_Calibrate(void)
 413 {
 414         #define CALIB_CLOCK                     32768
 415                 // CALIB_TICKS uses 2x frequency because we toggle twice per cycle
 416                 //  and adds 1/2 denom. to nom. to ensure rounding instead of flooring of integer division
 417         #define CALIB_TICKS                     ( (F_CPU+CALIB_CLOCK) / (2*CALIB_CLOCK) )
 418                 // Per AVR053, calibration guaranteed to take 1024 cycles (2048 half-cycles) or fewer;
 419                 //  add some cycles for response delay (5-10 after success) and response itself
 420         #define HALF_CYCLE_LIMIT        (2*1024 + 50)
 421         #define SUCCESS_TOGGLE_NUM      8
 422
 423         uint8_t ResponseStatus = STATUS_CMD_OK;
 424
 425         /* Don't entirely know why this is needed, something to do with the USB communication back to PC */
 426         Endpoint_ClearOUT();
 427         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 428         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 429
 430         /* Enable pullup on MISO and release ~RESET */
 431         DDRB    =  ~(1 << PB3);                                 // explicitly set all PORTB to outputs except PB3 (MISO)
 432         PORTB  |= ( (1 << PB4) | (1 << PB3) );  // set PB4 (TARG_RST) high (i.e. not reset) and enable pullup on PB3 (MISO)
 433
 434         /* Set up MISO pin (PCINT3) to listen for toggles */
 435         PCMSK0  = (1 << PCINT3);        // set mask to enable PCINT on only Pin 3 (MISO)
 436
 437         /* Set up timer that fires at a rate of 65536 Hz - this will drive the MOSI toggle */
 438         OCR1A   = CALIB_TICKS - 1;              // zero-indexed counter; for 16MHz system clock, this becomes 243
 439         TCCR1A  = ( (1 << WGM11) | (1 << WGM10) );                                      // set for fast PWM, TOP = OCR1A
 440         TCCR1B  = ( (1 << WGM13) | (1 << WGM12) | (1 << CS10) );        //  ... and no clock prescaling
 441         TCNT1   = 0;                                                                                            // reset counter
 442
 443         /* Initialize counter variables */
 444         HalfCyclesRemaining                     = HALF_CYCLE_LIMIT;
 445         ResponseTogglesRemaining        = SUCCESS_TOGGLE_NUM;
 446
 447         /* Turn on interrupts */
 448         PCICR  |= (1 << PCIE0); // enable interrupts for PCINT7:0 (don't touch setting for PCINT12:8)
 449         TIMSK1  = (1 << TOIE1); // enable T1 OVF interrupt (and no other T1 interrupts)
 450
 451         /* Turn on global interrupts for the following block, restoring current state at end */
 452         NONATOMIC_BLOCK(NONATOMIC_RESTORESTATE)
 453         {
 454                 /* Let device do its calibration, wait for reponse on MISO */
 455                 while ( HalfCyclesRemaining && ResponseTogglesRemaining )
 456                 {
 457                         // do nothing...
 458                 }
 459
 460                 /* Disable interrupts */
 461                 PCICR  &= ~(1 << PCIE0);
 462                 TIMSK1  = 0;
 463         }
 464
 465         /* Check if device responded with a success message or if we timed out */
 466         if (ResponseTogglesRemaining)
 467         {
 468                 ResponseStatus = STATUS_CMD_TOUT;
 469         }
 470
 471         /* Report back to PC via USB */
 472         Endpoint_Write_8(CMD_OSCCAL);
 473         Endpoint_Write_8(ResponseStatus);
 474         Endpoint_ClearIN();
 475
 476 } // void ISPProtocol_Calibrate(void)
 477
 478 /** Handler for the CMD_READ_FUSE_ISP, CMD_READ_LOCK_ISP, CMD_READ_SIGNATURE_ISP and CMD_READ_OSCCAL commands,
 479  *  reading the requested configuration byte from the device.
 480  *
 481  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 482  */
 483 void ISPProtocol_ReadFuseLockSigOSCCAL(uint8_t V2Command)
 484 {
 485         struct
 486         {
 487                 uint8_t RetByte;
 488                 uint8_t ReadCommandBytes[4];
 489         } Read_FuseLockSigOSCCAL_Params;
 490
 491         Endpoint_Read_Stream_LE(&Read_FuseLockSigOSCCAL_Params, sizeof(Read_FuseLockSigOSCCAL_Params), NULL);
 492
 493         Endpoint_ClearOUT();
 494         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 495         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 496
 497         uint8_t ResponseBytes[4];
 498
 499         /* Send the Fuse or Lock byte read commands as given by the host to the device, store response */
 500         for (uint8_t RByte = 0; RByte < sizeof(ResponseBytes); RByte++)
 501           ResponseBytes[RByte] = ISPTarget_TransferByte(Read_FuseLockSigOSCCAL_Params.ReadCommandBytes[RByte]);
 502
 503         Endpoint_Write_8(V2Command);
 504         Endpoint_Write_8(STATUS_CMD_OK);
 505         Endpoint_Write_8(ResponseBytes[Read_FuseLockSigOSCCAL_Params.RetByte - 1]);
 506         Endpoint_Write_8(STATUS_CMD_OK);
 507         Endpoint_ClearIN();
 508 }
 509
 510 /** Handler for the CMD_WRITE_FUSE_ISP and CMD_WRITE_LOCK_ISP commands, writing the requested configuration
 511  *  byte to the device.
 512  *
 513  *  \param[in] V2Command  Issued V2 Protocol command byte from the host
 514  */
 515 void ISPProtocol_WriteFuseLock(uint8_t V2Command)
 516 {
 517         struct
 518         {
 519                 uint8_t WriteCommandBytes[4];
 520         } Write_FuseLockSig_Params;
 521
 522         Endpoint_Read_Stream_LE(&Write_FuseLockSig_Params, sizeof(Write_FuseLockSig_Params), NULL);
 523
 524         Endpoint_ClearOUT();
 525         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 526         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 527
 528         /* Send the Fuse or Lock byte program commands as given by the host to the device */
 529         for (uint8_t SByte = 0; SByte < sizeof(Write_FuseLockSig_Params.WriteCommandBytes); SByte++)
 530           ISPTarget_SendByte(Write_FuseLockSig_Params.WriteCommandBytes[SByte]);
 531
 532         Endpoint_Write_8(V2Command);
 533         Endpoint_Write_8(STATUS_CMD_OK);
 534         Endpoint_Write_8(STATUS_CMD_OK);
 535         Endpoint_ClearIN();
 536 }
 537
 538 /** Handler for the CMD_SPI_MULTI command, writing and reading arbitrary SPI data to and from the attached device. */
 539 void ISPProtocol_SPIMulti(void)
 540 {
 541         struct
 542         {
 543                 uint8_t TxBytes;
 544                 uint8_t RxBytes;
 545                 uint8_t RxStartAddr;
 546                 uint8_t TxData[255];
 547         } SPI_Multi_Params;
 548
 549         Endpoint_Read_Stream_LE(&SPI_Multi_Params, (sizeof(SPI_Multi_Params) - sizeof(SPI_Multi_Params.TxData)), NULL);
 550         Endpoint_Read_Stream_LE(&SPI_Multi_Params.TxData, SPI_Multi_Params.TxBytes, NULL);
 551
 552         Endpoint_ClearOUT();
 553         Endpoint_SelectEndpoint(AVRISP_DATA_IN_EPADDR);
 554         Endpoint_SetEndpointDirection(ENDPOINT_DIR_IN);
 555
 556         Endpoint_Write_8(CMD_SPI_MULTI);
 557         Endpoint_Write_8(STATUS_CMD_OK);
 558
 559         uint8_t CurrTxPos = 0;
 560         uint8_t CurrRxPos = 0;
 561
 562         /* Write out bytes to transmit until the start of the bytes to receive is met */
 563         while (CurrTxPos < SPI_Multi_Params.RxStartAddr)
 564         {
 565                 if (CurrTxPos < SPI_Multi_Params.TxBytes)
 566                   ISPTarget_SendByte(SPI_Multi_Params.TxData[CurrTxPos]);
 567                 else
 568                   ISPTarget_SendByte(0);
 569
 570                 CurrTxPos++;
 571         }
 572
 573         /* Transmit remaining bytes with padding as needed, read in response bytes */
 574         while (CurrRxPos < SPI_Multi_Params.RxBytes)
 575         {
 576                 if (CurrTxPos < SPI_Multi_Params.TxBytes)
 577                   Endpoint_Write_8(ISPTarget_TransferByte(SPI_Multi_Params.TxData[CurrTxPos++]));
 578                 else
 579                   Endpoint_Write_8(ISPTarget_ReceiveByte());
 580
 581                 /* Check to see if we have filled the endpoint bank and need to send the packet */
 582                 if (!(Endpoint_IsReadWriteAllowed()))
 583                 {
 584                         Endpoint_ClearIN();
 585                         Endpoint_WaitUntilReady();
 586                 }
 587
 588                 CurrRxPos++;
 589         }
 590
 591         Endpoint_Write_8(STATUS_CMD_OK);
 592
 593         bool IsEndpointFull = !(Endpoint_IsReadWriteAllowed());
 594         Endpoint_ClearIN();
 595
 596         /* Ensure last packet is a short packet to terminate the transfer */
 597         if (IsEndpointFull)
 598         {
 599                 Endpoint_WaitUntilReady();
 600                 Endpoint_ClearIN();
 601                 Endpoint_WaitUntilReady();
 602         }
 603 }
 604
 605 /** Blocking delay for a given number of milliseconds. This provides a simple wrapper around
 606  *  the avr-libc provided delay function, so that the delay function can be called with a
 607  *  constant value (to prevent run-time floating point operations being required).
 608  *
 609  *  \param[in] DelayMS  Number of milliseconds to delay for
 610  */
 611 void ISPProtocol_DelayMS(uint8_t DelayMS)
 612 {
 613         while (DelayMS-- && TimeoutTicksRemaining)
 614           Delay_MS(1);
 615 }
 616
 617 #endif