/*
LUFA Library
- Copyright (C) Dean Camera, 2013.
+ Copyright (C) Dean Camera, 2018.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
- Copyright 2013 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+ Copyright 2018 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
#define __INCLUDE_FROM_TWI_C
#include "../TWI.h"
-uint8_t TWI_StartTransmission(TWI_t *twi,
+uint8_t TWI_StartTransmission(TWI_t* const TWI,
const uint8_t SlaveAddress,
const uint8_t TimeoutMS)
{
- uint16_t TimeoutRemaining;
-
- twi->MASTER.ADDR = SlaveAddress;
-
- TimeoutRemaining = (TimeoutMS * 100);
- while (TimeoutRemaining)
- {
- if (twi->MASTER.STATUS & (TWI_MASTER_WIF_bm | TWI_MASTER_ARBLOST_bm))
- {
- // Case 1: Arbitration lost. Try again. (or error)
- twi->MASTER.ADDR = SlaveAddress;
- }
- else if (twi->STATUS & (TWI_MASTER_WIF_bm | TWI_MASTER_RXACK_bm))
- {
- // Case 2: No response from slave.
- return TWI_ERROR_SlaveResponseTimeout;
- }
- else if (twi->STATUS & (TWI_MASTER_WIF_bm))
- {
- // Case 3: Slave ACK the Write. Ready!
- return TWI_ERROR_NoError;
- }
- else if (twi->STATUS & (TWI_MASTER_RIF_bm))
- {
- // Case 4: Slave ACK the Read. Ready! (a byte will be read)
- return TWI_ERROR_NoError;
- }
- // Still waiting..
- _delay_us(10);
- TimeoutRemaining--;
- }
-
- if (!(TimeoutRemaining)) {
- if (twi->MASTER.STATUS & TWI_MASTER_CLKHOLD_bm) {
- // Release the bus if we're holding it.
- twi->CTRLC = TWI_MASTER_CMD_STOP_gc;
- }
- return TWI_ERROR_BusCaptureTimeout;
- }
+ uint16_t TimeoutRemaining;
+
+ TWI->MASTER.ADDR = SlaveAddress;
+
+ TimeoutRemaining = (TimeoutMS * 100);
+ while (TimeoutRemaining)
+ {
+ uint8_t status = TWI->MASTER.STATUS;
+
+ if ((status & (TWI_MASTER_WIF_bm | TWI_MASTER_ARBLOST_bm)) == (TWI_MASTER_WIF_bm | TWI_MASTER_ARBLOST_bm))
+ {
+ TWI->MASTER.ADDR = SlaveAddress;
+ }
+ else if ((status & (TWI_MASTER_WIF_bm | TWI_MASTER_RXACK_bm)) == (TWI_MASTER_WIF_bm | TWI_MASTER_RXACK_bm))
+ {
+ TWI_StopTransmission(TWI);
+ return TWI_ERROR_SlaveResponseTimeout;
+ }
+ else if (status & (TWI_MASTER_WIF_bm | TWI_MASTER_RIF_bm))
+ {
+ return TWI_ERROR_NoError;
+ }
+
+ _delay_us(10);
+ TimeoutRemaining--;
+ }
+
+ if (!(TimeoutRemaining)) {
+ if (TWI->MASTER.STATUS & TWI_MASTER_CLKHOLD_bm) {
+ TWI_StopTransmission(TWI);
+ }
+ }
+
+ return TWI_ERROR_BusCaptureTimeout;
}
-bool TWI_SendByte(TWI_t *twi, const uint8_t Byte)
+bool TWI_SendByte(TWI_t* const TWI,
+ const uint8_t Byte)
{
- // We assume we're ready to write!
- twi->MASTER.DATA = Byte;
- while (!(twi->MASTER.STATUS & TWI_MASTER_WIF_bm));
- return (twi->MASTER.STATUS & TWI_MASTER_WIF_bm) & !(twi->MASTER.STATUS & TWI_MASTER_RXACK_bm);
+ TWI->MASTER.DATA = Byte;
+
+ while (!(TWI->MASTER.STATUS & TWI_MASTER_WIF_bm));
+
+ return (TWI->MASTER.STATUS & TWI_MASTER_WIF_bm) && !(TWI->MASTER.STATUS & TWI_MASTER_RXACK_bm);
}
-bool TWI_ReceiveByte(uint8_t* const Byte,
- const bool LastByte)
+bool TWI_ReceiveByte(TWI_t* const TWI,
+ uint8_t* const Byte,
+ const bool LastByte)
{
- // If we're here, we should already be reading. Wait if we haven't read yet.
- if (twi->MASTER.STATUS & (TWI_MASTER_BUSERR_bm | TWI_MASTER_ARBLOST_bm)) {
- return false;
- }
- while (!(twi->MASTER.STATUS & TWI_MASTER_RIF_bm));
- *byte = twi->MASTER.DATA;
- if (LastByte)
- twi->MASTER.CTRLC = TWI_MASTER_ACKACT_bm | TWI_MASTER_CMD_RECVTRANS_gc;
- else
- twi->MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;
- return true;
+ if ((TWI->MASTER.STATUS & (TWI_MASTER_BUSERR_bm | TWI_MASTER_ARBLOST_bm)) == (TWI_MASTER_BUSERR_bm | TWI_MASTER_ARBLOST_bm)) {
+ return false;
+ }
+
+ while (!(TWI->MASTER.STATUS & TWI_MASTER_RIF_bm));
+
+ *Byte = TWI->MASTER.DATA;
+
+ if (LastByte)
+ TWI->MASTER.CTRLC = TWI_MASTER_ACKACT_bm | TWI_MASTER_CMD_STOP_gc;
+ else
+ TWI->MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;
+
+ return true;
}
-uint8_t TWI_ReadPacket(TWI_t *twi,
+uint8_t TWI_ReadPacket(TWI_t* const TWI,
const uint8_t SlaveAddress,
const uint8_t TimeoutMS,
const uint8_t* InternalAddress,
uint8_t InternalAddressLen,
uint8_t* Buffer,
- uint8_t Length)
+ uint16_t Length)
{
uint8_t ErrorCode;
- if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
+ if ((ErrorCode = TWI_StartTransmission(TWI, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
TimeoutMS)) == TWI_ERROR_NoError)
{
while (InternalAddressLen--)
{
- if (!(TWI_SendByte(twi, *(InternalAddress++))))
+ if (!(TWI_SendByte(TWI, *(InternalAddress++))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
- if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ,
- TimeoutMS)) == TWI_ERROR_NoError)
+ if ((ErrorCode = TWI_StartTransmission(TWI, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ,
+ TimeoutMS)) == TWI_ERROR_NoError)
{
while (Length--)
{
- if (!(TWI_ReceiveByte(twi, Buffer++, (Length == 0))))
+ if (!(TWI_ReceiveByte(TWI, Buffer++, (Length == 0))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
-
- TWI_StopTransmission(twi);
}
+
+ TWI_StopTransmission(TWI);
}
return ErrorCode;
}
-uint8_t TWI_WritePacket(TWI_t *twi,
+uint8_t TWI_WritePacket(TWI_t* const TWI,
const uint8_t SlaveAddress,
const uint8_t TimeoutMS,
const uint8_t* InternalAddress,
uint8_t InternalAddressLen,
const uint8_t* Buffer,
- uint8_t Length)
+ uint16_t Length)
{
uint8_t ErrorCode;
- if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
+ if ((ErrorCode = TWI_StartTransmission(TWI, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
TimeoutMS)) == TWI_ERROR_NoError)
{
while (InternalAddressLen--)
{
- if (!(TWI_SendByte(twi, *(InternalAddress++))))
+ if (!(TWI_SendByte(TWI, *(InternalAddress++))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
while (Length--)
{
- if (!(TWI_SendByte(twi, *(Buffer++))))
+ if (!(TWI_SendByte(TWI, *(Buffer++))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
- TWI_StopTransmission(twi);
+ TWI_StopTransmission(TWI);
}
return ErrorCode;
projects / pub / USBasp.git / blobdiff