LUFA/Drivers/Peripheral/XMEGA/TWI_XMEGA.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2013.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2013  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaims all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 #include "../../../Common/Common.h"
  32 #if (ARCH == ARCH_XMEGA)
  33
  34 #define  __INCLUDE_FROM_TWI_C
  35 #include "../TWI.h"
  36
  37 uint8_t TWI_StartTransmission(TWI_t* const TWI,
  38                               const uint8_t SlaveAddress,
  39                               const uint8_t TimeoutMS)
  40 {
  41         uint16_t TimeoutRemaining;
  42
  43         TWI->MASTER.ADDR = SlaveAddress;
  44
  45         TimeoutRemaining = (TimeoutMS * 100);
  46         while (TimeoutRemaining)
  47         {
  48                 uint8_t status = TWI->MASTER.STATUS;
  49
  50                 if ((status & (TWI_MASTER_WIF_bm | TWI_MASTER_ARBLOST_bm)) == (TWI_MASTER_WIF_bm | TWI_MASTER_ARBLOST_bm))
  51                 {
  52                         TWI->MASTER.ADDR = SlaveAddress;
  53                 }
  54                 else if ((status & (TWI_MASTER_WIF_bm | TWI_MASTER_RXACK_bm)) == (TWI_MASTER_WIF_bm | TWI_MASTER_RXACK_bm))
  55                 {
  56                         TWI_StopTransmission(twi);
  57                         return TWI_ERROR_SlaveResponseTimeout;
  58                 }
  59                 else if (status & (TWI_MASTER_WIF_bm | TWI_MASTER_RIF_bm))
  60                 {
  61                         return TWI_ERROR_NoError;
  62                 }
  63
  64                 _delay_us(10);
  65                 TimeoutRemaining--;
  66         }
  67
  68         if (!(TimeoutRemaining)) {
  69                 if (TWI->MASTER.STATUS & TWI_MASTER_CLKHOLD_bm) {
  70                         TWI_StopTransmission(twi);
  71                 }
  72         }
  73
  74         return TWI_ERROR_BusCaptureTimeout;
  75 }
  76
  77 bool TWI_SendByte(TWI_t* const TWI,
  78                   const uint8_t Byte)
  79 {
  80         TWI->MASTER.DATA = Byte;
  81
  82         while (!(TWI->MASTER.STATUS & TWI_MASTER_WIF_bm));
  83
  84         return (TWI->MASTER.STATUS & TWI_MASTER_WIF_bm) && !(TWI->MASTER.STATUS & TWI_MASTER_RXACK_bm);
  85 }
  86
  87 bool TWI_ReceiveByte(TWI_t* const TWI,
  88                      uint8_t* const Byte,
  89                      const bool LastByte)
  90 {
  91         if ((TWI->MASTER.STATUS & (TWI_MASTER_BUSERR_bm | TWI_MASTER_ARBLOST_bm)) == (TWI_MASTER_BUSERR_bm | TWI_MASTER_ARBLOST_bm)) {
  92                 return false;
  93         }
  94
  95         while (!(TWI->MASTER.STATUS & TWI_MASTER_RIF_bm));
  96
  97         *Byte = TWI->MASTER.DATA;
  98
  99         if (LastByte)
 100           TWI->MASTER.CTRLC = TWI_MASTER_ACKACT_bm | TWI_MASTER_CMD_STOP_gc;
 101         else
 102           TWI->MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;
 103
 104         return true;
 105 }
 106
 107 uint8_t TWI_ReadPacket(TWI_t* const TWI,
 108                        const uint8_t SlaveAddress,
 109                        const uint8_t TimeoutMS,
 110                        const uint8_t* InternalAddress,
 111                        uint8_t InternalAddressLen,
 112                        uint8_t* Buffer,
 113                        uint8_t Length)
 114 {
 115         uint8_t ErrorCode;
 116
 117         if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
 118                                                TimeoutMS)) == TWI_ERROR_NoError)
 119         {
 120                 while (InternalAddressLen--)
 121                 {
 122                         if (!(TWI_SendByte(twi, *(InternalAddress++))))
 123                         {
 124                                 ErrorCode = TWI_ERROR_SlaveNAK;
 125                                 break;
 126                         }
 127                 }
 128
 129                 if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ,
 130                                                        TimeoutMS)) == TWI_ERROR_NoError)
 131                 {
 132                         while (Length--)
 133                         {
 134                                 if (!(TWI_ReceiveByte(twi, Buffer++, (Length == 0))))
 135                                 {
 136                                         ErrorCode = TWI_ERROR_SlaveNAK;
 137                                         break;
 138                                 }
 139                         }
 140                 }
 141
 142                 TWI_StopTransmission(twi);
 143         }
 144
 145         return ErrorCode;
 146 }
 147
 148 uint8_t TWI_WritePacket(TWI_t* const twi,
 149                         const uint8_t SlaveAddress,
 150                         const uint8_t TimeoutMS,
 151                         const uint8_t* InternalAddress,
 152                         uint8_t InternalAddressLen,
 153                         const uint8_t* Buffer,
 154                         uint8_t Length)
 155 {
 156         uint8_t ErrorCode;
 157
 158         if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
 159                                                TimeoutMS)) == TWI_ERROR_NoError)
 160         {
 161                 while (InternalAddressLen--)
 162                 {
 163                         if (!(TWI_SendByte(twi, *(InternalAddress++))))
 164                         {
 165                                 ErrorCode = TWI_ERROR_SlaveNAK;
 166                                 break;
 167                         }
 168                 }
 169
 170                 while (Length--)
 171                 {
 172                         if (!(TWI_SendByte(twi, *(Buffer++))))
 173                         {
 174                                 ErrorCode = TWI_ERROR_SlaveNAK;
 175                                 break;
 176                         }
 177                 }
 178
 179                 TWI_StopTransmission(twi);
 180         }
 181
 182         return ErrorCode;
 183 }
 184
 185 #endif