Add TWI Peripheral driver for XMEGA

1 files changed, 184 insertions, 0 deletions

diff --git a/LUFA/Drivers/Peripheral/XMEGA/TWI_XMEGA.c b/LUFA/Drivers/Peripheral/XMEGA/TWI_XMEGA.c
new file mode 100644
index 000000000..c4204e236
--- /dev/null
+++ b/LUFA/Drivers/Peripheral/XMEGA/TWI_XMEGA.c
@@ -0,0 +1,184 @@
+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2013.
+
+  dean [at] fourwalledcubicle [dot] com
+           www.lufa-lib.org
+*/
+
+/*
+  Copyright 2013  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_XMEGA)
+
+#define  __INCLUDE_FROM_TWI_C
+#include "../TWI.h"
+
+uint8_t TWI_StartTransmission(TWI_t *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;
+  }
+}
+
+bool TWI_SendByte(TWI_t *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);
+}
+
+bool TWI_ReceiveByte(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;
+}
+
+uint8_t TWI_ReadPacket(TWI_t *twi,
+                       const uint8_t SlaveAddress,
+                       const uint8_t TimeoutMS,
+                       const uint8_t* InternalAddress,
+                       uint8_t InternalAddressLen,
+                       uint8_t* Buffer,
+                       uint8_t Length)
+{
+	uint8_t ErrorCode;
+
+	if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
+	                                       TimeoutMS)) == TWI_ERROR_NoError)
+	{
+		while (InternalAddressLen--)
+		{
+			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)
+		{
+			while (Length--)
+			{
+				if (!(TWI_ReceiveByte(twi, Buffer++, (Length == 0))))
+				{
+					ErrorCode = TWI_ERROR_SlaveNAK;
+					break;
+				}
+			}
+
+			TWI_StopTransmission(twi);
+		}
+	}
+
+	return ErrorCode;
+}
+
+uint8_t TWI_WritePacket(TWI_t *twi,
+                        const uint8_t SlaveAddress,
+                        const uint8_t TimeoutMS,
+                        const uint8_t* InternalAddress,
+                        uint8_t InternalAddressLen,
+                        const uint8_t* Buffer,
+                        uint8_t Length)
+{
+	uint8_t ErrorCode;
+
+	if ((ErrorCode = TWI_StartTransmission(twi, (SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
+	                                       TimeoutMS)) == TWI_ERROR_NoError)
+	{
+		while (InternalAddressLen--)
+		{
+			if (!(TWI_SendByte(twi, *(InternalAddress++))))
+			{
+				ErrorCode = TWI_ERROR_SlaveNAK;
+				break;
+			}
+		}
+
+		while (Length--)
+		{
+			if (!(TWI_SendByte(twi, *(Buffer++))))
+			{
+				ErrorCode = TWI_ERROR_SlaveNAK;
+				break;
+			}
+		}
+
+		TWI_StopTransmission(twi);
+	}
+
+	return ErrorCode;
+}
+
+#endif