diff options
Diffstat (limited to 'LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c')
| -rw-r--r-- | LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c b/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c new file mode 100644 index 0000000000..eb08687be3 --- /dev/null +++ b/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.c @@ -0,0 +1,209 @@ +/* + LUFA Library + Copyright (C) Dean Camera, 2017. + + dean [at] fourwalledcubicle [dot] com + www.lufa-lib.org +*/ + +/* + Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com) + + Permission to use, copy, modify, distribute, and sell this + software and its documentation for any purpose is hereby granted + without fee, provided that the above copyright notice appear in + all copies and that both that the copyright notice and this + permission notice and warranty disclaimer appear in supporting + documentation, and that the name of the author not be used in + advertising or publicity pertaining to distribution of the + software without specific, written prior permission. + + The author disclaims all warranties with regard to this + software, including all implied warranties of merchantability + and fitness. In no event shall the author be liable for any + special, indirect or consequential damages or any damages + whatsoever resulting from loss of use, data or profits, whether + in an action of contract, negligence or other tortious action, + arising out of or in connection with the use or performance of + this software. +*/ + +#include "../../../Common/Common.h" +#if (ARCH == ARCH_AVR8) && defined(TWCR) + +#define __INCLUDE_FROM_TWI_C +#include "../TWI.h" + +uint8_t TWI_StartTransmission(const uint8_t SlaveAddress, + const uint8_t TimeoutMS) +{ + for (;;) + { + bool BusCaptured = false; + uint16_t TimeoutRemaining; + + TWCR = ((1 << TWINT) | (1 << TWSTA) | (1 << TWEN)); + + TimeoutRemaining = (TimeoutMS * 100); + while (TimeoutRemaining && !(BusCaptured)) + { + if (TWCR & (1 << TWINT)) + { + switch (TWSR & TW_STATUS_MASK) + { + case TW_START: + case TW_REP_START: + BusCaptured = true; + break; + case TW_MT_ARB_LOST: + TWCR = ((1 << TWINT) | (1 << TWSTA) | (1 << TWEN)); + continue; + default: + TWCR = (1 << TWEN); + return TWI_ERROR_BusFault; + } + } + + _delay_us(10); + TimeoutRemaining--; + } + + if (!(TimeoutRemaining)) + { + TWCR = (1 << TWEN); + return TWI_ERROR_BusCaptureTimeout; + } + + TWDR = SlaveAddress; + TWCR = ((1 << TWINT) | (1 << TWEN)); + + TimeoutRemaining = (TimeoutMS * 100); + while (TimeoutRemaining) + { + if (TWCR & (1 << TWINT)) + break; + + _delay_us(10); + TimeoutRemaining--; + } + + if (!(TimeoutRemaining)) + return TWI_ERROR_SlaveResponseTimeout; + + switch (TWSR & TW_STATUS_MASK) + { + case TW_MT_SLA_ACK: + case TW_MR_SLA_ACK: + return TWI_ERROR_NoError; + default: + TWCR = ((1 << TWINT) | (1 << TWSTO) | (1 << TWEN)); + return TWI_ERROR_SlaveNotReady; + } + } +} + +bool TWI_SendByte(const uint8_t Byte) +{ + TWDR = Byte; + TWCR = ((1 << TWINT) | (1 << TWEN)); + while (!(TWCR & (1 << TWINT))); + + return ((TWSR & TW_STATUS_MASK) == TW_MT_DATA_ACK); +} + +bool TWI_ReceiveByte(uint8_t* const Byte, + const bool LastByte) +{ + uint8_t TWCRMask; + + if (LastByte) + TWCRMask = ((1 << TWINT) | (1 << TWEN)); + else + TWCRMask = ((1 << TWINT) | (1 << TWEN) | (1 << TWEA)); + + TWCR = TWCRMask; + while (!(TWCR & (1 << TWINT))); + *Byte = TWDR; + + uint8_t Status = (TWSR & TW_STATUS_MASK); + + return ((LastByte) ? (Status == TW_MR_DATA_NACK) : (Status == TW_MR_DATA_ACK)); +} + +uint8_t TWI_ReadPacket(const uint8_t SlaveAddress, + const uint8_t TimeoutMS, + const uint8_t* InternalAddress, + uint8_t InternalAddressLen, + uint8_t* Buffer, + uint16_t Length) +{ + uint8_t ErrorCode; + + if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE, + TimeoutMS)) == TWI_ERROR_NoError) + { + while (InternalAddressLen--) + { + if (!(TWI_SendByte(*(InternalAddress++)))) + { + ErrorCode = TWI_ERROR_SlaveNAK; + break; + } + } + + if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ, + TimeoutMS)) == TWI_ERROR_NoError) + { + while (Length--) + { + if (!(TWI_ReceiveByte(Buffer++, (Length == 0)))) + { + ErrorCode = TWI_ERROR_SlaveNAK; + break; + } + } + + TWI_StopTransmission(); + } + } + + return ErrorCode; +} + +uint8_t TWI_WritePacket(const uint8_t SlaveAddress, + const uint8_t TimeoutMS, + const uint8_t* InternalAddress, + uint8_t InternalAddressLen, + const uint8_t* Buffer, + uint16_t Length) +{ + uint8_t ErrorCode; + + if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE, + TimeoutMS)) == TWI_ERROR_NoError) + { + while (InternalAddressLen--) + { + if (!(TWI_SendByte(*(InternalAddress++)))) + { + ErrorCode = TWI_ERROR_SlaveNAK; + break; + } + } + + while (Length--) + { + if (!(TWI_SendByte(*(Buffer++)))) + { + ErrorCode = TWI_ERROR_SlaveNAK; + break; + } + } + + TWI_StopTransmission(); + } + + return ErrorCode; +} + +#endif |