/* ----------------------------------------------------------------------------
 *         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,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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 * ----------------------------------------------------------------------------
 */

#ifndef SPID_H
#define SPID_H

//------------------------------------------------------------------------------
//         Headers
//------------------------------------------------------------------------------

#include <board.h>

//------------------------------------------------------------------------------
//         Definitions
//------------------------------------------------------------------------------

/// An unspecified error has occured.
#define SPID_ERROR          1

/// SPI driver is currently in use.
#define SPID_ERROR_LOCK     2

//------------------------------------------------------------------------------
//         Macros
//------------------------------------------------------------------------------

/// Calculates the value of the SCBR field of the Chip Select Register given
/// MCK and SPCK.
#define SPID_CSR_SCBR(mck, spck)    ((((mck) / (spck)) << 8) & AT91C_SPI_SCBR)

/// Calculates the value of the DLYBS field of the Chip Select Register given
/// the delay in ns and MCK.
#define SPID_CSR_DLYBS(mck, delay) \
    ((((((delay) * ((mck) / 1000000)) / 1000) + 1)  << 16) & AT91C_SPI_DLYBS)

/// Calculates the value of the DLYBCT field of the Chip Select Register given
/// the delay in ns and MCK.
#define SPID_CSR_DLYBCT(mck, delay) \
    ((((((delay) / 32 * ((mck) / 1000000)) / 1000) + 1) << 24) & AT91C_SPI_DLYBCT)

//------------------------------------------------------------------------------
//         Types
//------------------------------------------------------------------------------

/// SPI transfer complete callback.
typedef void (*SpidCallback )(unsigned char, void *);

//------------------------------------------------------------------------------
/// Spi Transfer Request prepared by the application upper layer. This structure
/// is sent to the SPI_SendCommand function to start the transfer. At the end of 
/// the transfer, the callback is invoked by the interrupt handler.
//------------------------------------------------------------------------------
typedef struct _SpidCmd {

    /// Pointer to the command data.
	unsigned char *pCmd;
    /// Command size in bytes.
	unsigned char cmdSize;
    /// Pointer to the data to be sent.
	unsigned char *pData;
    /// Data size in bytes.
	unsigned short dataSize;
    /// SPI chip select.
	unsigned char spiCs;
    /// Callback function invoked at the end of transfer.
	SpidCallback callback;
    /// Callback arguments.
	void *pArgument;

} SpidCmd;

//------------------------------------------------------------------------------
/// Constant structure associated with SPI port. This structure prevents
/// client applications to have access in the same time.
//------------------------------------------------------------------------------
typedef struct {

    /// Pointer to SPI Hardware registers
	AT91S_SPI *pSpiHw;
    /// SPI Id as defined in the product datasheet
	char spiId;
    /// Current SpiCommand being processed
	SpidCmd *pCurrentCommand;
    /// Mutual exclusion semaphore.
	volatile char semaphore;

} Spid;

//------------------------------------------------------------------------------
//         Exported functions
//------------------------------------------------------------------------------

extern unsigned char SPID_Configure(
    Spid *pSpid,
    AT91S_SPI *pSpiHw,
    unsigned char spiId);

extern void SPID_ConfigureCS(Spid *pSpid, unsigned char cs, unsigned int csr);
	
extern unsigned char SPID_SendCommand(
	Spid *pSpid,
	SpidCmd *pCommand);

extern void SPID_Handler(Spid *pSpid);

extern unsigned char SPID_IsBusy(const Spid *pSpid);

#endif // #ifndef SPID_H