board/sandpoint/flash.c

/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program 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 of
 * the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <mpc824x.h>
#include <asm/processor.h>
#include <asm/pci_io.h>
#include <w83c553f.h>

#define ROM_CS0_START	0xFF800000
#define ROM_CS1_START	0xFF000000

flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS]; /* info for FLASH chips    */

#if defined(CONFIG_ENV_IS_IN_FLASH)
# ifndef  CONFIG_ENV_ADDR
#  define CONFIG_ENV_ADDR  (CONFIG_SYS_FLASH_BASE + CONFIG_ENV_OFFSET)
# endif
# ifndef  CONFIG_ENV_SIZE
#  define CONFIG_ENV_SIZE  CONFIG_ENV_SECT_SIZE
# endif
# ifndef  CONFIG_ENV_SECT_SIZE
#  define CONFIG_ENV_SECT_SIZE  CONFIG_ENV_SIZE
# endif
#endif

/*-----------------------------------------------------------------------
 * Functions
 */
static int write_word (flash_info_t *info, ulong dest, ulong data);
#if 0
static void flash_get_offsets (ulong base, flash_info_t *info);
#endif /* 0 */

/*flash command address offsets*/

#if 0
#define ADDR0           (0x555)
#define ADDR1           (0x2AA)
#define ADDR3           (0x001)
#else
#define ADDR0		(0xAAA)
#define ADDR1		(0x555)
#define ADDR3		(0x001)
#endif

#define FLASH_WORD_SIZE unsigned char

/*-----------------------------------------------------------------------
 */

#if 0
static int byte_parity_odd(unsigned char x) __attribute__ ((const));
#endif /* 0 */
static unsigned long flash_id(unsigned char mfct, unsigned char chip) __attribute__ ((const));

typedef struct
{
  FLASH_WORD_SIZE extval;
  unsigned short intval;
} map_entry;

#if 0
static int
byte_parity_odd(unsigned char x)
{
  x ^= x >> 4;
  x ^= x >> 2;
  x ^= x >> 1;
  return (x & 0x1) != 0;
}
#endif /* 0 */


static unsigned long
flash_id(unsigned char mfct, unsigned char chip)
{
  static const map_entry mfct_map[] =
    {
      {(FLASH_WORD_SIZE) AMD_MANUFACT,	(unsigned short) ((unsigned long) FLASH_MAN_AMD >> 16)},
      {(FLASH_WORD_SIZE) FUJ_MANUFACT,	(unsigned short) ((unsigned long) FLASH_MAN_FUJ >> 16)},
      {(FLASH_WORD_SIZE) STM_MANUFACT,	(unsigned short) ((unsigned long) FLASH_MAN_STM >> 16)},
      {(FLASH_WORD_SIZE) MT_MANUFACT,	(unsigned short) ((unsigned long) FLASH_MAN_MT >> 16)},
      {(FLASH_WORD_SIZE) INTEL_MANUFACT,(unsigned short) ((unsigned long) FLASH_MAN_INTEL >> 16)},
      {(FLASH_WORD_SIZE) INTEL_ALT_MANU,(unsigned short) ((unsigned long) FLASH_MAN_INTEL >> 16)}
    };

  static const map_entry chip_map[] =
  {
    {AMD_ID_F040B,	FLASH_AM040},
    {(FLASH_WORD_SIZE) STM_ID_x800AB,	FLASH_STM800AB}
  };

  const map_entry *p;
  unsigned long result = FLASH_UNKNOWN;

  /* find chip id */
  for(p = &chip_map[0]; p < &chip_map[sizeof chip_map / sizeof chip_map[0]]; p++)
    if(p->extval == chip)
    {
      result = FLASH_VENDMASK | p->intval;
      break;
    }

  /* find vendor id */
  for(p = &mfct_map[0]; p < &mfct_map[sizeof mfct_map / sizeof mfct_map[0]]; p++)
    if(p->extval == mfct)
    {
      result &= ~FLASH_VENDMASK;
      result |= (unsigned long) p->intval << 16;
      break;
    }

  return result;
}


unsigned long
flash_init(void)
{
  unsigned long i;
  unsigned char j;
  static const ulong flash_banks[] = CONFIG_SYS_FLASH_BANKS;

  /* Init: no FLASHes known */
  for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++)
  {
    flash_info_t * const pflinfo = &flash_info[i];
    pflinfo->flash_id = FLASH_UNKNOWN;
    pflinfo->size = 0;
    pflinfo->sector_count = 0;
  }

  /* Enable writes to Sandpoint flash */
  {
    register unsigned char temp;
    CONFIG_READ_BYTE(CONFIG_SYS_WINBOND_ISA_CFG_ADDR + WINBOND_CSCR, temp);
    temp &= ~0x20; /* clear BIOSWP bit */
    CONFIG_WRITE_BYTE(CONFIG_SYS_WINBOND_ISA_CFG_ADDR + WINBOND_CSCR, temp);
  }

  for(i = 0; i < sizeof flash_banks / sizeof flash_banks[0]; i++)
  {
    flash_info_t * const pflinfo = &flash_info[i];
    const unsigned long base_address = flash_banks[i];
    volatile FLASH_WORD_SIZE * const flash = (FLASH_WORD_SIZE *) base_address;
#if 0
    volatile FLASH_WORD_SIZE * addr2;
#endif
#if 0
    /* write autoselect sequence */
    flash[0x5555] = 0xaa;
    flash[0x2aaa] = 0x55;
    flash[0x5555] = 0x90;
#else
    flash[0xAAA << (3 * i)] = 0xaa;
    flash[0x555 << (3 * i)] = 0x55;
    flash[0xAAA << (3 * i)] = 0x90;
#endif
    __asm__ __volatile__("sync");

#if 0
    pflinfo->flash_id = flash_id(flash[0x0], flash[0x1]);
#else
    pflinfo->flash_id = flash_id(flash[0x0], flash[0x2 + 14 * i]);
#endif

    switch(pflinfo->flash_id & FLASH_TYPEMASK)
    {
      case FLASH_AM040:
	pflinfo->size = 0x00080000;
	pflinfo->sector_count = 8;
	for(j = 0; j < 8; j++)
	{
	  pflinfo->start[j] = base_address + 0x00010000 * j;
	  pflinfo->protect[j] = flash[(j << 16) | 0x2];
	}
	break;
      case FLASH_STM800AB:
	pflinfo->size = 0x00100000;
	pflinfo->sector_count = 19;
	pflinfo->start[0] = base_address;
	pflinfo->start[1] = base_address + 0x4000;
	pflinfo->start[2] = base_address + 0x6000;
	pflinfo->start[3] = base_address + 0x8000;
	for(j = 1; j < 16; j++)
	{
	  pflinfo->start[j+3] = base_address + 0x00010000 * j;
	}
#if 0
	/* check for protected sectors */
	for (j = 0; j < pflinfo->sector_count; j++) {
	  /* read sector protection at sector address, (A7 .. A0) = 0x02 */
	  /* D0 = 1 if protected */
	  addr2 = (volatile FLASH_WORD_SIZE *)(pflinfo->start[j]);
	    if (pflinfo->flash_id & FLASH_MAN_SST)
	      pflinfo->protect[j] = 0;
	    else
	      pflinfo->protect[j] = addr2[2] & 1;
	}
#endif
	break;
    }
    /* Protect monitor and environment sectors
     */
#if CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE
    flash_protect(FLAG_PROTECT_SET,
		CONFIG_SYS_MONITOR_BASE,
		CONFIG_SYS_MONITOR_BASE + monitor_flash_len - 1,
		&flash_info[0]);
#endif

#if defined(CONFIG_ENV_IS_IN_FLASH) && defined(CONFIG_ENV_ADDR)
    flash_protect(FLAG_PROTECT_SET,
		CONFIG_ENV_ADDR,
		CONFIG_ENV_ADDR + CONFIG_ENV_SIZE - 1,
		&flash_info[0]);
#endif

    /* reset device to read mode */
    flash[0x0000] = 0xf0;
    __asm__ __volatile__("sync");
  }

    return flash_info[0].size + flash_info[1].size;
}

#if 0
static void
flash_get_offsets (ulong base, flash_info_t *info)
{
    int i;

    /* set up sector start address table */
	if (info->flash_id & FLASH_MAN_SST)
	  {
	    for (i = 0; i < info->sector_count; i++)
	      info->start[i] = base + (i * 0x00010000);
	  }
	else
    if (info->flash_id & FLASH_BTYPE) {
	/* set sector offsets for bottom boot block type    */
	info->start[0] = base + 0x00000000;
	info->start[1] = base + 0x00004000;
	info->start[2] = base + 0x00006000;
	info->start[3] = base + 0x00008000;
	for (i = 4; i < info->sector_count; i++) {
	    info->start[i] = base + (i * 0x00010000) - 0x00030000;
	}
    } else {
	/* set sector offsets for top boot block type       */
	i = info->sector_count - 1;
	info->start[i--] = base + info->size - 0x00004000;
	info->start[i--] = base + info->size - 0x00006000;
	info->start[i--] = base + info->size - 0x00008000;
	for (; i >= 0; i--) {
	    info->start[i] = base + i * 0x00010000;
	}
    }

}
#endif /* 0 */

/*-----------------------------------------------------------------------
 */
void
flash_print_info(flash_info_t *info)
{
  static const char unk[] = "Unknown";
  const char *mfct = unk, *type = unk;
  unsigned int i;

  if(info->flash_id != FLASH_UNKNOWN)
  {
    switch(info->flash_id & FLASH_VENDMASK)
    {
      case FLASH_MAN_AMD:	mfct = "AMD";				break;
      case FLASH_MAN_FUJ:	mfct = "FUJITSU";			break;
      case FLASH_MAN_STM:	mfct = "STM";				break;
      case FLASH_MAN_SST:	mfct = "SST";				break;
      case FLASH_MAN_BM:	mfct = "Bright Microelectonics";	break;
      case FLASH_MAN_INTEL:	mfct = "Intel";				break;
    }

    switch(info->flash_id & FLASH_TYPEMASK)
    {
      case FLASH_AM040:		type = "AM29F040B (512K * 8, uniform sector size)";	break;
      case FLASH_AM400B:	type = "AM29LV400B (4 Mbit, bottom boot sect)";		break;
      case FLASH_AM400T:	type = "AM29LV400T (4 Mbit, top boot sector)";		break;
      case FLASH_AM800B:	type = "AM29LV800B (8 Mbit, bottom boot sect)";		break;
      case FLASH_AM800T:	type = "AM29LV800T (8 Mbit, top boot sector)";		break;
      case FLASH_AM160T:	type = "AM29LV160T (16 Mbit, top boot sector)";		break;
      case FLASH_AM320B:	type = "AM29LV320B (32 Mbit, bottom boot sect)";	break;
      case FLASH_AM320T:	type = "AM29LV320T (32 Mbit, top boot sector)";		break;
      case FLASH_STM800AB:	type = "M29W800AB (8 Mbit, bottom boot sect)";		break;
      case FLASH_SST800A:	type = "SST39LF/VF800 (8 Mbit, uniform sector size)";	break;
      case FLASH_SST160A:	type = "SST39LF/VF160 (16 Mbit, uniform sector size)";	break;
    }
  }

  printf(
    "\n  Brand: %s Type: %s\n"
    "  Size: %lu KB in %d Sectors\n",
    mfct,
    type,
    info->size >> 10,
    info->sector_count
  );

  printf ("  Sector Start Addresses:");

  for (i = 0; i < info->sector_count; i++)
  {
    unsigned long size;
    unsigned int erased;
    unsigned long * flash = (unsigned long *) info->start[i];

    /*
     * Check if whole sector is erased
     */
    size =
      (i != (info->sector_count - 1)) ?
      (info->start[i + 1] - info->start[i]) >> 2 :
      (info->start[0] + info->size - info->start[i]) >> 2;

    for(
      flash = (unsigned long *) info->start[i], erased = 1;
      (flash != (unsigned long *) info->start[i] + size) && erased;
      flash++
    )
      erased = *flash == ~0x0UL;

    printf(
      "%s %08lX %s %s",
      (i % 5) ? "" : "\n   ",
      info->start[i],
      erased ? "E" : " ",
      info->protect[i] ? "RO" : "  "
    );
  }

  puts("\n");
  return;
}

#if 0

/*
 * The following code cannot be run from FLASH!
 */
ulong
flash_get_size (vu_long *addr, flash_info_t *info)
{
   short i;
    FLASH_WORD_SIZE value;
    ulong base = (ulong)addr;
	volatile FLASH_WORD_SIZE *addr2 = (FLASH_WORD_SIZE *)addr;

    printf("flash_get_size: \n");
    /* Write auto select command: read Manufacturer ID */
    eieio();
    addr2[ADDR0] = (FLASH_WORD_SIZE)0xAA;
    addr2[ADDR1] = (FLASH_WORD_SIZE)0x55;
    addr2[ADDR0] = (FLASH_WORD_SIZE)0x90;
    value = addr2[0];

    switch (value) {
    case (FLASH_WORD_SIZE)AMD_MANUFACT:
	info->flash_id = FLASH_MAN_AMD;
	break;
    case (FLASH_WORD_SIZE)FUJ_MANUFACT:
	info->flash_id = FLASH_MAN_FUJ;
	break;
    case (FLASH_WORD_SIZE)SST_MANUFACT:
	info->flash_id = FLASH_MAN_SST;
	break;
    default:
	info->flash_id = FLASH_UNKNOWN;
	info->sector_count = 0;
	info->size = 0;
	return (0);         /* no or unknown flash  */
    }
    printf("recognised manufacturer");

    value = addr2[ADDR3];          /* device ID        */
	debug ("\ndev_code=%x\n", value);

    switch (value) {
    case (FLASH_WORD_SIZE)AMD_ID_LV400T:
	info->flash_id += FLASH_AM400T;
	info->sector_count = 11;
	info->size = 0x00080000;
	break;              /* => 0.5 MB        */

    case (FLASH_WORD_SIZE)AMD_ID_LV400B:
	info->flash_id += FLASH_AM400B;
	info->sector_count = 11;
	info->size = 0x00080000;
	break;              /* => 0.5 MB        */

    case (FLASH_WORD_SIZE)AMD_ID_LV800T:
	info->flash_id += FLASH_AM800T;
	info->sector_count = 19;
	info->size = 0x00100000;
	break;              /* => 1 MB      */

    case (FLASH_WORD_SIZE)AMD_ID_LV800B:
	info->flash_id += FLASH_AM800B;
	info->sector_count = 19;
	info->size = 0x00100000;
	break;              /* => 1 MB      */

    case (FLASH_WORD_SIZE)AMD_ID_LV160T:
	info->flash_id += FLASH_AM160T;
	info->sector_count = 35;
	info->size = 0x00200000;
	break;              /* => 2 MB      */

    case (FLASH_WORD_SIZE)AMD_ID_LV160B:
	info->flash_id += FLASH_AM160B;
	info->sector_count = 35;
	info->size = 0x00200000;
	break;              /* => 2 MB      */

    case (FLASH_WORD_SIZE)SST_ID_xF800A:
	info->flash_id += FLASH_SST800A;
	info->sector_count = 16;
	info->size = 0x00100000;
	break;              /* => 1 MB      */

    case (FLASH_WORD_SIZE)SST_ID_xF160A:
	info->flash_id += FLASH_SST160A;
	info->sector_count = 32;
	info->size = 0x00200000;
	break;              /* => 2 MB      */

    case (FLASH_WORD_SIZE)AMD_ID_F040B:
	info->flash_id += FLASH_AM040;
	info->sector_count = 8;
	info->size = 0x00080000;
	break;              /* => 0.5 MB      */

    default:
	info->flash_id = FLASH_UNKNOWN;
	return (0);         /* => no or unknown flash */

    }

    printf("flash id %lx; sector count %x, size %lx\n", info->flash_id,info->sector_count,info->size);
    /* set up sector start address table */
	if (info->flash_id & FLASH_MAN_SST)
	  {
	    for (i = 0; i < info->sector_count; i++)
	      info->start[i] = base + (i * 0x00010000);
	  }
	else
    if (info->flash_id & FLASH_BTYPE) {
	/* set sector offsets for bottom boot block type    */
	info->start[0] = base + 0x00000000;
	info->start[1] = base + 0x00004000;
	info->start[2] = base + 0x00006000;
	info->start[3] = base + 0x00008000;
	for (i = 4; i < info->sector_count; i++) {
	    info->start[i] = base + (i * 0x00010000) - 0x00030000;
	}
    } else {
	/* set sector offsets for top boot block type       */
	i = info->sector_count - 1;
	info->start[i--] = base + info->size - 0x00004000;
	info->start[i--] = base + info->size - 0x00006000;
	info->start[i--] = base + info->size - 0x00008000;
	for (; i >= 0; i--) {
	    info->start[i] = base + i * 0x00010000;
	}
    }

    /* check for protected sectors */
    for (i = 0; i < info->sector_count; i++) {
	/* read sector protection at sector address, (A7 .. A0) = 0x02 */
	/* D0 = 1 if protected */
	addr2 = (volatile FLASH_WORD_SIZE *)(info->start[i]);
		if (info->flash_id & FLASH_MAN_SST)
		  info->protect[i] = 0;
		else
		  info->protect[i] = addr2[2] & 1;
    }

    /*
     * Prevent writes to uninitialized FLASH.
     */
    if (info->flash_id != FLASH_UNKNOWN) {
       addr2 = (FLASH_WORD_SIZE *)info->start[0];
	*addr2 = (FLASH_WORD_SIZE)0x00F000F0;   /* reset bank */
    }

    return (info->size);
}

#endif


int
flash_erase(flash_info_t *info, int s_first, int s_last)
{
    volatile FLASH_WORD_SIZE *addr = (FLASH_WORD_SIZE *)(info->start[0]);
    int flag, prot, sect, l_sect;
    ulong start, now, last;
    unsigned char sh8b;

    if ((s_first < 0) || (s_first > s_last)) {
	if (info->flash_id == FLASH_UNKNOWN) {
	    printf ("- missing\n");
	} else {
	    printf ("- no sectors to erase\n");
	}
	return 1;
    }

    if ((info->flash_id == FLASH_UNKNOWN) ||
	(info->flash_id > (FLASH_MAN_STM | FLASH_AMD_COMP))) {
	printf ("Can't erase unknown flash type - aborted\n");
	return 1;
    }

    prot = 0;
    for (sect=s_first; sect<=s_last; ++sect) {
	if (info->protect[sect]) {
	    prot++;
	}
    }

    if (prot) {
	printf ("- Warning: %d protected sectors will not be erased!\n",
	    prot);
    } else {
	printf ("\n");
    }

    l_sect = -1;

    /* Check the ROM CS */
    if ((info->start[0] >= ROM_CS1_START) && (info->start[0] < ROM_CS0_START))
      sh8b = 3;
    else
      sh8b = 0;

    /* Disable interrupts which might cause a timeout here */
    flag = disable_interrupts();

    addr[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00AA00AA;
    addr[ADDR1 << sh8b] = (FLASH_WORD_SIZE)0x00550055;
    addr[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00800080;
    addr[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00AA00AA;
    addr[ADDR1 << sh8b] = (FLASH_WORD_SIZE)0x00550055;

    /* Start erase on unprotected sectors */
    for (sect = s_first; sect<=s_last; sect++) {
	if (info->protect[sect] == 0) { /* not protected */
	    addr = (FLASH_WORD_SIZE *)(info->start[0] + (
				(info->start[sect] - info->start[0]) << sh8b));
			if (info->flash_id & FLASH_MAN_SST)
			  {
			    addr[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00AA00AA;
			    addr[ADDR1 << sh8b] = (FLASH_WORD_SIZE)0x00550055;
			    addr[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00800080;
			    addr[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00AA00AA;
			    addr[ADDR1 << sh8b] = (FLASH_WORD_SIZE)0x00550055;
			    addr[0] = (FLASH_WORD_SIZE)0x00500050;  /* block erase */
			    udelay(30000);  /* wait 30 ms */
			  }
			else
			  addr[0] = (FLASH_WORD_SIZE)0x00300030;  /* sector erase */
	    l_sect = sect;
	}
    }

    /* re-enable interrupts if necessary */
    if (flag)
	enable_interrupts();

    /* wait at least 80us - let's wait 1 ms */
    udelay (1000);

    /*
     * We wait for the last triggered sector
     */
    if (l_sect < 0)
	goto DONE;

    start = get_timer (0);
    last  = start;
    addr = (FLASH_WORD_SIZE *)(info->start[0] + (
			(info->start[l_sect] - info->start[0]) << sh8b));
    while ((addr[0] & (FLASH_WORD_SIZE)0x00800080) != (FLASH_WORD_SIZE)0x00800080) {
	if ((now = get_timer(start)) > CONFIG_SYS_FLASH_ERASE_TOUT) {
	    printf ("Timeout\n");
	    return 1;
	}
	/* show that we're waiting */
	if ((now - last) > 1000) {  /* every second */
	    serial_putc ('.');
	    last = now;
	}
    }

DONE:
    /* reset to read mode */
    addr = (FLASH_WORD_SIZE *)info->start[0];
    addr[0] = (FLASH_WORD_SIZE)0x00F000F0;  /* reset bank */

    printf (" done\n");
    return 0;
}

/*-----------------------------------------------------------------------
 * Copy memory to flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */

int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
    ulong cp, wp, data;
    int i, l, rc;

    wp = (addr & ~3);   /* get lower word aligned address */

    /*
     * handle unaligned start bytes
     */
    if ((l = addr - wp) != 0) {
	data = 0;
	for (i=0, cp=wp; i<l; ++i, ++cp) {
	    data = (data << 8) | (*(uchar *)cp);
	}
	for (; i<4 && cnt>0; ++i) {
	    data = (data << 8) | *src++;
	    --cnt;
	    ++cp;
	}
	for (; cnt==0 && i<4; ++i, ++cp) {
	    data = (data << 8) | (*(uchar *)cp);
	}

	if ((rc = write_word(info, wp, data)) != 0) {
	    return (rc);
	}
	wp += 4;
    }

    /*
     * handle word aligned part
     */
    while (cnt >= 4) {
	data = 0;
	for (i=0; i<4; ++i) {
	    data = (data << 8) | *src++;
	}
	if ((rc = write_word(info, wp, data)) != 0) {
	    return (rc);
	}
	wp  += 4;
	cnt -= 4;
    }

    if (cnt == 0) {
	return (0);
    }

    /*
     * handle unaligned tail bytes
     */
    data = 0;
    for (i=0, cp=wp; i<4 && cnt>0; ++i, ++cp) {
	data = (data << 8) | *src++;
	--cnt;
    }
    for (; i<4; ++i, ++cp) {
	data = (data << 8) | (*(uchar *)cp);
    }

    return (write_word(info, wp, data));
}

/*-----------------------------------------------------------------------
 * Write a word to Flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */
static int write_word (flash_info_t *info, ulong dest, ulong data)
{
	volatile FLASH_WORD_SIZE *addr2 = (FLASH_WORD_SIZE *)info->start[0];
	volatile FLASH_WORD_SIZE *dest2;
	volatile FLASH_WORD_SIZE *data2 = (FLASH_WORD_SIZE *)&data;
    ulong start;
    int flag;
	int i;
    unsigned char sh8b;

    /* Check the ROM CS */
    if ((info->start[0] >= ROM_CS1_START) && (info->start[0] < ROM_CS0_START))
      sh8b = 3;
    else
      sh8b = 0;

    dest2 = (FLASH_WORD_SIZE *)(((dest - info->start[0]) << sh8b) +
				info->start[0]);

    /* Check if Flash is (sufficiently) erased */
    if ((*dest2 & (FLASH_WORD_SIZE)data) != (FLASH_WORD_SIZE)data) {
	return (2);
    }
    /* Disable interrupts which might cause a timeout here */
    flag = disable_interrupts();

	for (i=0; i<4/sizeof(FLASH_WORD_SIZE); i++)
	  {
	    addr2[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00AA00AA;
	    addr2[ADDR1 << sh8b] = (FLASH_WORD_SIZE)0x00550055;
	    addr2[ADDR0 << sh8b] = (FLASH_WORD_SIZE)0x00A000A0;

	    dest2[i << sh8b] = data2[i];

	    /* re-enable interrupts if necessary */
	    if (flag)
	      enable_interrupts();

	    /* data polling for D7 */
	    start = get_timer (0);
	    while ((dest2[i << sh8b] & (FLASH_WORD_SIZE)0x00800080) !=
		   (data2[i] & (FLASH_WORD_SIZE)0x00800080)) {
	      if (get_timer(start) > CONFIG_SYS_FLASH_WRITE_TOUT) {
		return (1);
	      }
	    }
	  }

    return (0);
}

/*-----------------------------------------------------------------------
 */