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//==========================================================================

//

//      flash_unlock_block.c

//

//      Flash programming

//

//==========================================================================

// ####ECOSGPLCOPYRIGHTBEGIN####                                            

// -------------------------------------------                              

// This file is part of eCos, the Embedded Configurable Operating System.   

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under    

// the terms of the GNU General Public License as published by the Free     

// Software Foundation; either version 2 or (at your option) any later      

// version.                                                                 

//

// eCos is distributed in the hope that it will be useful, but WITHOUT      

// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    

// for more details.                                                        

//

// You should have received a copy of the GNU General Public License        

// along with eCos; if not, write to the Free Software Foundation, Inc.,    

// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            

//

// As a special exception, if other files instantiate templates or use      

// macros or inline functions from this file, or you compile this file      

// and link it with other works to produce a work based on this file,       

// this file does not by itself cause the resulting work to be covered by   

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// General Public License v2.                                               

//

// This exception does not invalidate any other reasons why a work based    

// on this file might be covered by the GNU General Public License.         

// -------------------------------------------                              

// ####ECOSGPLCOPYRIGHTEND####                                              

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    gthomas

// Contributors: gthomas, msalter

// Date:         2000-09-10

// Purpose:      

// Description:  

//              

//####DESCRIPTIONEND####

//

//==========================================================================

#include "flash.h"

//

// The difficulty with this operation is that the hardware does not support

// unlocking single blocks.  However, the logical layer would like this to

// be the case, so this routine emulates it.  The hardware can clear all of

// the locks in the device at once.  This routine will use that approach and

// then reset the regions which are known to be locked.

//

#define MAX_FLASH_BLOCKS 128

int

flash_unlock_block(volatile unsigned char *block, int block_size, int blocks)

        __attribute__ ((section (".2ram.flash_unlock_block")));

int

flash_unlock_block(volatile unsigned char *block, int block_size, int blocks)

{

    volatile unsigned short *ROM, *bp;

    unsigned short stat;

    int timeout = 5000000;

    unsigned short is_locked[MAX_FLASH_BLOCKS];

    int i;

    ROM = (unsigned short *) FLASH_P2V((unsigned long)block & 0xFF800000);

    // Clear any error conditions

    ROM[0] = FLASH_Clear_Status;

    // Get current block lock state.  This needs to access each block on

    // the device so currently locked blocks can be re-locked.

    bp = (unsigned short *)((unsigned long)block & 0xFF800000);

    for (i = 0;  i < blocks;  i++) {

        if (bp == (unsigned short *) block) {

            is_locked[i] = 0;

        } else {

            *(volatile unsigned short *)FLASH_P2V(bp) = FLASH_Read_Query;

            is_locked[i] = ((volatile unsigned short *)FLASH_P2V(bp))[2];

        }

        bp += block_size / sizeof(*bp);

    }

    // Clears all lock bits

    FLASH_P2V(block)[0] = FLASH_Clear_Locks;

    FLASH_P2V(block)[0] = FLASH_Clear_Locks_Confirm;  // Confirmation

    timeout = 5000000;

    while(((stat = ROM[0]) & FLASH_Status_Ready) != FLASH_Status_Ready) {

        if (--timeout == 0) goto done;

    }

    // Restore the lock state

    bp = (unsigned short *)((unsigned long)block & 0xFF800000);

    for (i = 0;  i < blocks;  i++) {

        if (is_locked[i]) {

            *FLASH_P2V(bp) = FLASH_Set_Lock;

            *FLASH_P2V(bp) = FLASH_Set_Lock_Confirm;  // Confirmation

            timeout = 5000000;

            while(((stat = ROM[0]) & FLASH_Status_Ready) != FLASH_Status_Ready) {

                if (--timeout == 0) goto done;

            }

        }

        bp += block_size / sizeof(*bp);

    }

 done:

    // Restore ROM to "normal" mode

    ROM[0] = FLASH_Reset;

    return stat;

}