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/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support
 * ----------------------------------------------------------------------------
 * Copyright (c) 2008, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 */
 
//------------------------------------------------------------------------------
/// \unit
///
/// !Purpose
///
/// Interface for configuration the Two Wire Interface (TWI) peripheral.
///
/// !Usage
///
/// -# Configures a TWI peripheral to operate in master mode, at the given
/// frequency (in Hz) using TWI_ConfigureMaster().
/// -# or if hardware possible, configures a TWI peripheral to operate in 
/// slave mode, at the given frequency (in Hz) using TWI_ConfigureSlave().
/// -# Sends a STOP condition on the TWI using TWI_Stop().
/// -# Starts a read operation on the TWI bus with the specified slave using
/// TWI_StartRead(). Data must then be read using TWI_ReadByte() whenever 
/// a byte is available (poll using TWI_ByteReceived()).
/// -# Starts a write operation on the TWI to access the selected slave using
/// TWI_StartWrite(). A byte of data must be provided to start the write;
/// other bytes are written next. 
/// -# Sends a byte of data to one of the TWI slaves on the bus using TWI_WriteByte().
/// This function must be called once before TWI_StartWrite() with the first byte of data
/// to send, then it shall be called repeatedly after that to send the remaining bytes.
/// -# Check if a byte has been received and can be read on the given TWI
/// peripheral using TWI_ByteReceived(). 
/// Check if a byte has been sent using TWI_ByteSent().
/// -# Check if the current transmission is complete (the STOP has been sent)
/// using TWI_TransferComplete().
/// -# Enables & disable the selected interrupts sources on a TWI peripheral
/// using TWI_EnableIt() and TWI_DisableIt().
/// -# Get current status register of the given TWI peripheral using
/// TWI_GetStatus(). Get current status register of the given TWI peripheral, but
/// masking interrupt sources which are not currently enabled using 
/// TWI_GetMaskedStatus().
//------------------------------------------------------------------------------
 
#ifndef TWI_H
#define TWI_H
 
//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------
 
#include <board.h>
 
//------------------------------------------------------------------------------
//         Global definitions
//------------------------------------------------------------------------------
 
// Missing AT91C_TWI_TXRDY definition.
#ifndef AT91C_TWI_TXRDY
    #define AT91C_TWI_TXRDY   AT91C_TWI_TXRDY_MASTER
#endif
 
// Missing AT91C_TWI_TXCOMP definition.
#ifndef AT91C_TWI_TXCOMP
    #define AT91C_TWI_TXCOMP  AT91C_TWI_TXCOMP_MASTER
#endif
 
//------------------------------------------------------------------------------
//         Global macros
//------------------------------------------------------------------------------
 
/// Returns 1 if the TXRDY bit (ready to transmit data) is set in the given
/// status register value.
#define TWI_STATUS_TXRDY(status) ((status & AT91C_TWI_TXRDY) == AT91C_TWI_TXRDY)
 
/// Returns 1 if the RXRDY bit (ready to receive data) is set in the given
/// status register value.
#define TWI_STATUS_RXRDY(status) ((status & AT91C_TWI_RXRDY) == AT91C_TWI_RXRDY)
 
/// Returns 1 if the TXCOMP bit (transfer complete) is set in the given
/// status register value.
#define TWI_STATUS_TXCOMP(status) ((status & AT91C_TWI_TXCOMP) == AT91C_TWI_TXCOMP)
 
//------------------------------------------------------------------------------
//         Global functions
//------------------------------------------------------------------------------
 
extern void TWI_ConfigureMaster(AT91S_TWI *pTwi, unsigned int twck, unsigned int mck);
 
#ifdef AT91C_TWI_SVEN  // TWI slave
extern void TWI_ConfigureSlave(AT91S_TWI *pTwi, unsigned char slaveAddress);
#endif
 
extern void TWI_Stop(AT91S_TWI *pTwi);
 
extern void TWI_StartRead(
    AT91S_TWI *pTwi,
    unsigned char address,
    unsigned int iaddress,
    unsigned char isize);
 
extern unsigned char TWI_ReadByte(AT91S_TWI *pTwi);
 
extern void TWI_WriteByte(AT91S_TWI *pTwi, unsigned char byte);
 
extern void TWI_StartWrite(
    AT91S_TWI *pTwi,
    unsigned char address,
    unsigned int iaddress,
    unsigned char isize,
    unsigned char byte);
 
extern unsigned char TWI_ByteReceived(AT91S_TWI *pTwi);
 
extern unsigned char TWI_ByteSent(AT91S_TWI *pTwi);
 
extern unsigned char TWI_TransferComplete(AT91S_TWI *pTwi);
 
extern void TWI_EnableIt(AT91S_TWI *pTwi, unsigned int sources);
 
extern void TWI_DisableIt(AT91S_TWI *pTwi, unsigned int sources);
 
extern unsigned int TWI_GetStatus(AT91S_TWI *pTwi);
 
extern unsigned int TWI_GetMaskedStatus(AT91S_TWI *pTwi);
 
extern void TWI_SendSTOPCondition(AT91S_TWI *pTwi);
 
#endif //#ifndef TWI_H