/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support
 * ----------------------------------------------------------------------------
 * Copyright (c) 2009, 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:
 *
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 * 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.
 *
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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/** \addtogroup flashd_module Flash Memory Interface
 * The flash driver manages the programming, erasing, locking and unlocking sequences
 * with dedicated commands.
 *
 * To implement flash programing operation, the user has to follow these few steps :
 * <ul>
 * <li>Configue flash wait states to initializes the flash. </li>
 * <li>Checks whether a region to be programmed is locked. </li>
 * <li>Unlocks the user region to be programmed if the region have locked before.</li>
 * <li>Erases the user page before program (optional).</li>
 * <li>Writes the user page from the page buffer.</li>
 * <li>Locks the region of programmed area if any.</li>
 * </ul>
 *
 * Writing 8-bit and 16-bit data is not allowed and may lead to unpredictable data corruption.
 * A check of this validity and padding for 32-bit alignment should be done in write algorithm.

 * Lock/unlock range associated with the user address range is automatically translated.
 *
 * This security bit can be enabled through the command "Set General Purpose NVM Bit 0".
 *
 * A 128-bit factory programmed unique ID could be read to serve several purposes.
 *
 * The driver accesses the flash memory by calling the lowlevel module provided in \ref efc_module.
 * For more accurate information, please look at the EEFC section of the Datasheet.
 *
 * Related files :\n
 * \ref flashd.c\n
 * \ref flashd.h.\n
 * \ref efc.c\n
 * \ref efc.h.\n
*/
/*@{*/
/*@}*/


/**
 * \file
 *
 * The flash driver provides the unified interface for flash program operations.
 *
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/
#include "chip.h"

#include <string.h>
#include <assert.h>

/*----------------------------------------------------------------------------
 *        Local variables
 *----------------------------------------------------------------------------*/

//static NO_INIT uint8_t _aucPageBuffer[IFLASH_PAGE_SIZE] ;
static NO_INIT uint32_t _adwPageBuffer[IFLASH_PAGE_SIZE/4] ;
static uint8_t* _aucPageBuffer = (uint8_t*)_adwPageBuffer;
static NO_INIT uint32_t _dwUseIAP ;

/*----------------------------------------------------------------------------
 *        Local macros
 *----------------------------------------------------------------------------*/

#define min( a, b ) (((a) < (b)) ? (a) : (b))

/*----------------------------------------------------------------------------
 *        Local functions
 *----------------------------------------------------------------------------*/


/**
 * \brief Computes the lock range associated with the given address range.
 *
 * \param dwStart  Start address of lock range.
 * \param dwEnd  End address of lock range.
 * \param pdwActualStart  Actual start address of lock range.
 * \param pdwActualEnd  Actual end address of lock range.
 */
static void ComputeLockRange( uint32_t dwStart, uint32_t dwEnd, uint32_t *pdwActualStart, uint32_t *pdwActualEnd )
{
    Efc* pStartEfc ;
    Efc* pEndEfc ;
    uint16_t wStartPage ;
    uint16_t wEndPage ;
    uint16_t wNumPagesInRegion ;
    uint16_t wActualStartPage ;
    uint16_t wActualEndPage ;

    // Convert start and end address in page numbers
    EFC_TranslateAddress( &pStartEfc, dwStart, &wStartPage, 0 ) ;
    EFC_TranslateAddress( &pEndEfc, dwEnd, &wEndPage, 0 ) ;

    // Find out the first page of the first region to lock
    wNumPagesInRegion = IFLASH_LOCK_REGION_SIZE / IFLASH_PAGE_SIZE ;
    wActualStartPage = wStartPage - (wStartPage % wNumPagesInRegion) ;
    wActualEndPage = wEndPage ;

    if ( (wEndPage % wNumPagesInRegion) != 0 )
    {
        wActualEndPage += wNumPagesInRegion - (wEndPage % wNumPagesInRegion) ;
    }
    // Store actual page numbers
    EFC_ComputeAddress( pStartEfc, wActualStartPage, 0, pdwActualStart ) ;
    EFC_ComputeAddress( pEndEfc, wActualEndPage, 0, pdwActualEnd ) ;
}


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

/**
 * \brief Initializes the flash driver.
 *
 * \param mck  Master clock frequency in Hz.
 */

extern void FLASHD_Initialize( uint32_t dwMCk, uint32_t dwUseIAP )
{
    EFC_DisableFrdyIt( EFC ) ;
	
    if ( (dwMCk/1000000) >= 64 )
	{
        EFC_SetWaitState( EFC, 2 ) ;
    }
    else
	{
	    if ( (dwMCk/1000000) >= 50 )
	    {
            EFC_SetWaitState( EFC, 1 ) ;
        }
        else
	    {
            EFC_SetWaitState( EFC, 0 ) ;
        }
	}

    _dwUseIAP=dwUseIAP ;
}

/**
 * \brief Erases the entire flash.
 *
 * \param address  Flash start address.
 * \return 0 if successful; otherwise returns an error code.
 */
extern uint32_t FLASHD_Erase( uint32_t dwAddress )
{
    Efc* pEfc ;
    uint16_t wPage ;
    uint16_t wOffset ;
    uint32_t dwError ;

    assert( (dwAddress >=IFLASH_ADDR) || (dwAddress <= (IFLASH_ADDR + IFLASH_SIZE)) ) ;

    // Translate write address
    EFC_TranslateAddress( &pEfc, dwAddress, &wPage, &wOffset ) ;
    dwError = EFC_PerformCommand( pEfc, EFC_FCMD_EA, 0, _dwUseIAP ) ;
	
    return dwError ;
}

/**
 * \brief Writes a data buffer in the internal flash
 *
 * \note This function works in polling mode, and thus only returns when the
 * data has been effectively written.
 * \param address  Write address.
 * \param pBuffer  Data buffer.
 * \param size  Size of data buffer in bytes.
 * \return 0 if successful, otherwise returns an error code.
 */
extern uint32_t FLASHD_Write( uint32_t dwAddress, const void *pvBuffer, uint32_t dwSize )
{
    Efc* pEfc ;
    uint16_t page ;
    uint16_t offset ;
    uint32_t writeSize ;
    uint32_t pageAddress ;
    uint16_t padding ;
    uint32_t dwError ;
    uint32_t sizeTmp ;
    uint32_t *pAlignedDestination ;
    uint32_t *pAlignedSource ;

    assert( pvBuffer ) ;
    assert( dwAddress >=IFLASH_ADDR ) ;
    assert( (dwAddress + dwSize) <= (IFLASH_ADDR + IFLASH_SIZE) ) ;

    /* Translate write address */
    EFC_TranslateAddress( &pEfc, dwAddress, &page, &offset ) ;

    /* Write all pages */
    while ( dwSize > 0 )
    {
        /* Copy data in temporary buffer to avoid alignment problems */
        writeSize = min((uint32_t)IFLASH_PAGE_SIZE - offset, dwSize ) ;
        EFC_ComputeAddress(pEfc, page, 0, &pageAddress ) ;
        padding = IFLASH_PAGE_SIZE - offset - writeSize ;

        /* Pre-buffer data */
        memcpy( _aucPageBuffer, (void *) pageAddress, offset);

        /* Buffer data */
        memcpy( _aucPageBuffer + offset, pvBuffer, writeSize);

        /* Post-buffer data */
        memcpy( _aucPageBuffer + offset + writeSize, (void *) (pageAddress + offset + writeSize), padding);

        /* Write page
         * Writing 8-bit and 16-bit data is not allowed and may lead to unpredictable data corruption
         */
        pAlignedDestination = (uint32_t*)pageAddress ;
        pAlignedSource = (uint32_t*)_adwPageBuffer ;
        sizeTmp = IFLASH_PAGE_SIZE ;

        while ( sizeTmp >= 4 )
        {
            *pAlignedDestination++ = *pAlignedSource++;
            sizeTmp -= 4;
        }

        /* Send writing command */
        dwError = EFC_PerformCommand( pEfc, EFC_FCMD_EWP, page, _dwUseIAP ) ;
        if ( dwError )
        {
            return dwError ;
        }

        /* Progression */
        dwAddress += IFLASH_PAGE_SIZE ;
        pvBuffer = (void *)((uint32_t) pvBuffer + writeSize) ;
        dwSize -= writeSize ;
        page++;
        offset = 0;
    }

    return 0 ;
}
/**
 * \brief Locks all the regions in the given address range. The actual lock range is
 * reported through two output parameters.
 *
 * \param start  Start address of lock range.
 * \param end    End address of lock range.
 * \param pActualStart  Start address of the actual lock range (optional).
 * \param pActualEnd  End address of the actual lock range (optional).
 * \return 0 if successful, otherwise returns an error code.
 */
extern uint32_t FLASHD_Lock( uint32_t start, uint32_t end, uint32_t *pActualStart, uint32_t *pActualEnd )
{
    Efc *pEfc ;
    uint32_t actualStart, actualEnd ;
    uint16_t startPage, endPage ;
    uint32_t dwError ;
    uint16_t numPagesInRegion = IFLASH_LOCK_REGION_SIZE / IFLASH_PAGE_SIZE;

    /* Compute actual lock range and store it */
    ComputeLockRange( start, end, &actualStart, &actualEnd ) ;
    if ( pActualStart != NULL )
    {
        *pActualStart = actualStart ;
    }
    if ( pActualEnd != NULL )
    {
        *pActualEnd = actualEnd;
    }

    /* Compute page numbers */
    EFC_TranslateAddress( &pEfc, actualStart, &startPage, 0 ) ;
    EFC_TranslateAddress( 0, actualEnd, &endPage, 0 ) ;

    /* Lock all pages */
    while ( startPage < endPage )
    {
        dwError = EFC_PerformCommand( pEfc, EFC_FCMD_SLB, startPage, _dwUseIAP ) ;
        if ( dwError )
        {
            return dwError ;
        }
        startPage += numPagesInRegion;
    }

    return 0 ;
}

/**
 * \brief Unlocks all the regions in the given address range. The actual unlock range is
 * reported through two output parameters.
 * \param start  Start address of unlock range.
 * \param end  End address of unlock range.
 * \param pActualStart  Start address of the actual unlock range (optional).
 * \param pActualEnd  End address of the actual unlock range (optional).
 * \return 0 if successful, otherwise returns an error code.
 */
extern uint32_t FLASHD_Unlock( uint32_t start, uint32_t end, uint32_t *pActualStart, uint32_t *pActualEnd )
{
    Efc* pEfc ;
    uint32_t actualStart, actualEnd ;
    uint16_t startPage, endPage ;
    uint32_t dwError ;
    uint16_t numPagesInRegion = IFLASH_LOCK_REGION_SIZE / IFLASH_PAGE_SIZE;

    // Compute actual unlock range and store it
    ComputeLockRange(start, end, &actualStart, &actualEnd);
    if ( pActualStart != NULL )
    {
        *pActualStart = actualStart ;
    }
    if ( pActualEnd != NULL )
    {
        *pActualEnd = actualEnd ;
    }

    // Compute page numbers
    EFC_TranslateAddress( &pEfc, actualStart, &startPage, 0 ) ;
    EFC_TranslateAddress( 0, actualEnd, &endPage, 0 ) ;

    // Unlock all pages
    while ( startPage < endPage )
    {
        dwError = EFC_PerformCommand( pEfc, EFC_FCMD_CLB, startPage, _dwUseIAP ) ;
        if ( dwError )
        {
            return dwError ;
        }
        startPage += numPagesInRegion ;
    }
    return 0 ;
}

/**
 * \brief Returns the number of locked regions inside the given address range.
 *
 * \param start  Start address of range
 * \param end    End address of range.
 */
extern uint32_t FLASHD_IsLocked( uint32_t start, uint32_t end )
{
    Efc *pEfc ;
    uint16_t startPage, endPage ;
    uint8_t startRegion, endRegion ;
    uint32_t numPagesInRegion ;
    uint32_t status ;
    uint32_t dwError ;
    uint32_t numLockedRegions = 0 ;

    assert( end >= start ) ;
    assert( (start >=IFLASH_ADDR) && (end <= IFLASH_ADDR + IFLASH_SIZE) ) ;

    // Compute page numbers
    EFC_TranslateAddress( &pEfc, start, &startPage, 0 ) ;
    EFC_TranslateAddress( 0, end, &endPage, 0 ) ;

    // Compute region numbers
    numPagesInRegion = IFLASH_LOCK_REGION_SIZE / IFLASH_PAGE_SIZE ;
    startRegion = startPage / numPagesInRegion ;
    endRegion = endPage / numPagesInRegion ;
    if ((endPage % numPagesInRegion) != 0)
    {
        endRegion++ ;
    }

    // Retrieve lock status
    dwError = EFC_PerformCommand( pEfc, EFC_FCMD_GLB, 0, _dwUseIAP ) ;
    assert( !dwError ) ;
    status = EFC_GetResult( pEfc ) ;

    // Check status of each involved region
    while ( startRegion < endRegion )
    {
        if ( (status & (1 << startRegion)) != 0 )
        {
            numLockedRegions++ ;
        }
        startRegion++ ;
    }

    return numLockedRegions ;
}

/**
 * \brief Check if the given GPNVM bit is set or not.
 *
 * \param gpnvm  GPNVM bit index.
 * \returns 1 if the given GPNVM bit is currently set; otherwise returns 0.
 */
extern uint32_t FLASHD_IsGPNVMSet( uint8_t ucGPNVM )
{
    uint32_t dwError ;
    uint32_t dwStatus ;

    assert( ucGPNVM < 2 ) ;

    /* Get GPNVMs status */
    dwError = EFC_PerformCommand( EFC, EFC_FCMD_GFB, 0, _dwUseIAP ) ;
    assert( !dwError ) ;
    dwStatus = EFC_GetResult( EFC ) ;

    /* Check if GPNVM is set */
    if ( (dwStatus & (1 << ucGPNVM)) != 0 )
    {
        return 1 ;
    }
    else
    {
        return 0 ;
    }
}

/**
 * \brief Sets the selected GPNVM bit.
 *
 * \param gpnvm  GPNVM bit index.
 * \returns 0 if successful; otherwise returns an error code.
 */
extern uint32_t FLASHD_SetGPNVM( uint8_t ucGPNVM )
{
    assert( ucGPNVM < 2 ) ;

    if ( !FLASHD_IsGPNVMSet( ucGPNVM ) )
    {
        return EFC_PerformCommand( EFC, EFC_FCMD_SFB, ucGPNVM, _dwUseIAP ) ;
    }
    else
    {
        return 0 ;
    }
}

/**
 * \brief Clears the selected GPNVM bit.
 *
 * \param gpnvm  GPNVM bit index.
 * \returns 0 if successful; otherwise returns an error code.
 */
extern uint32_t FLASHD_ClearGPNVM( uint8_t ucGPNVM )
{
    assert( ucGPNVM < 2 ) ;

    if ( FLASHD_IsGPNVMSet( ucGPNVM ) )
    {
        return EFC_PerformCommand( EFC, EFC_FCMD_CFB, ucGPNVM, _dwUseIAP ) ;
    }
    else
    {
        return 0 ;
    }
}
/**
 * \brief Read the unique ID.
 *
 * \param uniqueID pointer on a 4bytes char containing the unique ID value.
 * \returns 0 if successful; otherwise returns an error code.
 */
extern uint32_t FLASHD_ReadUniqueID( uint32_t* pdwUniqueID )
{
    uint32_t dwError ;

    assert( pdwUniqueID != NULL ) ;

    pdwUniqueID[0] = 0 ;
    pdwUniqueID[1] = 0 ;
    pdwUniqueID[2] = 0 ;
    pdwUniqueID[3] = 0 ;

    EFC_StartCommand( EFC, EFC_FCMD_STUI, 0 ) ;

    pdwUniqueID[0] = *(uint32_t*) IFLASH_ADDR;
    pdwUniqueID[1] = *(uint32_t*)(IFLASH_ADDR + 4) ;
    pdwUniqueID[2] = *(uint32_t*)(IFLASH_ADDR + 8) ;
    pdwUniqueID[3] = *(uint32_t*)(IFLASH_ADDR + 12) ;

    dwError = EFC_PerformCommand( EFC, EFC_FCMD_SPUI, 0, _dwUseIAP ) ;
    if ( dwError )
    {
        return dwError ;
    }

    return 0 ;
}