/* ----------------------------------------------------------------------------
 *         SAM Software Package License
 * ----------------------------------------------------------------------------
 * Copyright (c) 2012, Atmel Corporation
 *
 * All rights reserved.
 *
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 * modification, are permitted provided that the following conditions are met:
 *
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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 programming operation, the user has to follow these few 
 * steps :
 * <ul>
 * <li>Configure 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>

/*----------------------------------------------------------------------------
 *        Definitions
 *----------------------------------------------------------------------------*/

#define GPNVM_NUM_MAX    9

/*----------------------------------------------------------------------------
 *        Local variables
 *----------------------------------------------------------------------------*/

static uint32_t _pdwPageBuffer[IFLASH_PAGE_SIZE/sizeof(uint32_t)] ;
static uint32_t _dwUseIAP = 1; /* Use IAP interface by default. */


/*----------------------------------------------------------------------------
 *        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 ) ;
	TRACE_DEBUG( "Actual lock range is 0x%06X - 0x%06X\n\r",
			(unsigned int)*pdwActualStart, (unsigned int)*pdwActualEnd ) ;
}


/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Initializes the flash driver.
 *
 * \param dwMCk     Master clock frequency in Hz.
 * \param dwUseIAP  0: use EEFC controller interface, 1: use IAP interface.
 *                  dwUseIAP should be set to 1 when running out of flash.
 */

extern void FLASHD_Initialize( uint32_t dwMCk, uint32_t dwUseIAP )
{
	dwMCk = dwMCk; /* avoid warnings */

	EFC_DisableFrdyIt( EFC ) ;
	_dwUseIAP = dwUseIAP ;
}

/**
 * \brief Erases the entire flash.
 *
 * \param dwAddress  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 Erases flash by sector.
 *
 * \param dwAddress  Start address of be erased sector.
 *
 * \return 0 if successful; otherwise returns an error code.
 */
extern uint32_t FLASHD_EraseSector( 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_ES, wPage, _dwUseIAP ) ;

	return dwError ;
}

/**
 * \brief Erases flash by pages.
 *
 * \param dwAddress  Start address of be erased pages.
 * \param dwPageNum  Number of pages to be erased with EPA command (4, 8, 16, 32)
 *
 * \return 0 if successful; otherwise returns an error code.
 */
extern uint32_t FLASHD_ErasePages( uint32_t dwAddress, uint32_t dwPageNum )
{
	Efc* pEfc ;
	uint16_t wPage ;
	uint16_t wOffset ;
	uint32_t dwError ;
	static uint32_t dwFarg ;

	assert( (dwAddress >=IFLASH_ADDR) || (dwAddress <= (IFLASH_ADDR + IFLASH_SIZE)) ) ;

	/* Translate write address */
	EFC_TranslateAddress( &pEfc, dwAddress, &wPage, &wOffset ) ;

	/* Get FARG field for EPA command:
	 * The first page to be erased is specified in the FARG[15:2] field of
	 * the MC_FCR register. The first page number must be modulo 4, 8,16 or 32
	 * according to the number of pages to erase at the same time.
	 *
	 * The 2 lowest bits of the FARG field define the number of pages to
	 * be erased (FARG[1:0]).
	 */
	if (dwPageNum == 32) {
		wPage &= ~(32u - 1u);
		dwFarg = (wPage << 2) | 3; /* 32 pages */
	} else if (dwPageNum == 16) {
		wPage &= ~(16u - 1u);
		dwFarg = (wPage << 2) | 2; /* 16 pages */
	} else if (dwPageNum == 8) {
		wPage &= ~(8u - 1u);
		dwFarg = (wPage << 2) | 1; /* 8 pages */
	} else {
		wPage &= ~(4u - 1u);
		dwFarg = (wPage << 2) | 0; /* 4 pages */
	}
	dwError = EFC_PerformCommand( pEfc, EFC_FCMD_EPA, dwFarg, _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 dwIdx ;
	uint32_t *pAlignedDestination ;
	uint8_t  *pucPageBuffer = (uint8_t *)_pdwPageBuffer;

	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( pucPageBuffer, (void *) pageAddress, offset);

		/* Buffer data */
		memcpy( pucPageBuffer + offset, pvBuffer, writeSize);

		/* Post-buffer data */
		memcpy( pucPageBuffer + 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 ;
		for (dwIdx = 0; dwIdx < (IFLASH_PAGE_SIZE / sizeof(uint32_t)); ++ dwIdx) {
			*pAlignedDestination++ = _pdwPageBuffer[dwIdx];
			memory_barrier()
		}

		/* Note: It is not possible to use Erase and write Command (EWP) on all Flash
		(this command is available on the First 2 Small Sector, 16K Bytes). 
		For the next block, Erase them first then use Write page command. */

		/* Send writing command */
		dwError = EFC_PerformCommand( pEfc, EFC_FCMD_WP, page, _dwUseIAP ) ;
		if ( dwError ) {
			return dwError ;
		}

		/* Progression */
		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 )
{
	uint32_t i, j;
	Efc *pEfc ;
	uint16_t startPage, endPage ;
	uint8_t startRegion, endRegion ;
	uint32_t numPagesInRegion ;
	uint32_t status[IFLASH_NB_OF_LOCK_BITS / 32u] ;
	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 */
	EFC_PerformCommand( pEfc, EFC_FCMD_GLB, 0, _dwUseIAP ) ;
	for (i = 0; i < (IFLASH_NB_OF_LOCK_BITS / 32u); i++) {
		status[i] = EFC_GetResult( pEfc ) ;
	}

	/* Check status of each involved region */
	while ( startRegion < endRegion ) {
		i = startRegion / 32u;
		j = startRegion % 32u;
		if ( (status[i] & (1 << j)) != 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 dwStatus ;

	assert( ucGPNVM < GPNVM_NUM_MAX ) ;

	/* Get GPNVMs status */
	EFC_PerformCommand( EFC, EFC_FCMD_GFB, 0, _dwUseIAP ) ;
	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 < GPNVM_NUM_MAX ) ;

	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 < GPNVM_NUM_MAX ) ;

	if ( FLASHD_IsGPNVMSet( ucGPNVM ) ) {
		return EFC_PerformCommand( EFC, EFC_FCMD_CFB, ucGPNVM, _dwUseIAP ) ;
	} else {
		return 0 ;
	}
}

/**
 * \brief Read the unique ID.
 *
 * \param pdwUniqueID pointer on a 4bytes char containing the unique ID value.
 * \returns 0 if successful; otherwise returns an error code.
 */
#ifdef __ICCARM__
extern __ramfunc uint32_t FLASHD_ReadUniqueID( uint32_t* pdwUniqueID )
#else
	__attribute__ ((section (".ramfunc")))
uint32_t FLASHD_ReadUniqueID( uint32_t* pdwUniqueID )
#endif
{
	uint32_t status ;
	if (pdwUniqueID == NULL) {
		return 1;
	}

	pdwUniqueID[0] = 0 ;
	pdwUniqueID[1] = 0 ;
	pdwUniqueID[2] = 0 ;
	pdwUniqueID[3] = 0 ;

	/* Send the Start Read unique Identifier command (STUI) by writing the Flash
	   Command Register with the STUI command.*/
	EFC->EEFC_FCR = EEFC_FCR_FKEY_PASSWD | EFC_FCMD_STUI;

	/* When the Unique Identifier is ready to be read, the FRDY bit in the Flash
	   Programming Status Register (EEFC_FSR) falls. */
	do {
		status = EFC->EEFC_FSR ;
	} while ( (status & EEFC_FSR_FRDY) == EEFC_FSR_FRDY ) ;

	/* The Unique Identifier is located in the first 128 bits of the Flash
	   memory mapping. So, at the address 0x400000-0x40000F. */
	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);

	/* To stop the Unique Identifier mode, the user needs to send the Stop Read
	   unique Identifier command (SPUI) by writing the Flash Command Register
	   with the SPUI command. */
	EFC->EEFC_FCR = EEFC_FCR_FKEY_PASSWD | EFC_FCMD_SPUI ;

	/* When the Stop read Unique Unique Identifier command (SPUI) has been
	performed, the FRDY bit in the Flash Programming Status Register (EEFC_FSR)
	rises. */
	do {
		status = EFC->EEFC_FSR ;
	} while ( (status & EEFC_FSR_FRDY) != EEFC_FSR_FRDY ) ;

	return 0;
}