board/rbc823/flash.c - u-boot - Git at Google

 /*
  * (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 <mpc8xx.h>

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

 /*-----------------------------------------------------------------------
  * Functions
  */
 static ulong flash_get_size (vu_long *addr, flash_info_t *info);
 static int write_word (flash_info_t *info, ulong dest, ulong data);
 static void flash_get_offsets (ulong base, flash_info_t *info);

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

 unsigned long flash_init (void)
 {
 	unsigned long size_b0, size_b1;
 	int i;

 	/* Init: no FLASHes known */
 	for (i=0; i < CFG_MAX_FLASH_BANKS; ++i)
 	    flash_info[i].flash_id = FLASH_UNKNOWN;

 	/* Detect size */
 	size_b0 = flash_get_size((vu_long *)CFG_FLASH_BASE, &flash_info[0]);

 	/* Setup offsets */
 	flash_get_offsets (CFG_FLASH_BASE, &flash_info[0]);

 #if CFG_MONITOR_BASE >= CFG_FLASH_BASE
 	/* Monitor protection ON by default */
 	flash_protect(FLAG_PROTECT_SET,
 		      CFG_MONITOR_BASE,
 		      CFG_MONITOR_BASE+monitor_flash_len-1,
 		      &flash_info[0]);
 #endif

 	size_b1 = 0 ;

 	flash_info[1].flash_id = FLASH_UNKNOWN;
 	flash_info[1].sector_count = -1;

 	flash_info[0].size = size_b0;
 	flash_info[1].size = size_b1;

 	return (size_b0 + size_b1);
 }

 /*-----------------------------------------------------------------------
  * Fix this to support variable sector sizes
 */
 static void flash_get_offsets (ulong base, flash_info_t *info)
 {
 	int i;

 	/* set up sector start address table */
 	if ((info->flash_id & FLASH_TYPEMASK) == FLASH_AM040) {
 		/* set sector offsets for bottom boot block type	*/
 		for (i = 0; i < info->sector_count; i++)
 			info->start[i] = base + (i * 0x00010000);
 	}
 }

 /*-----------------------------------------------------------------------
  */
 void flash_print_info  (flash_info_t *info)
 {
 	int i;

 	if (info->flash_id == FLASH_UNKNOWN)
 	{
 		puts ("missing or unknown FLASH type\n");
 		return;
 	}

 	switch (info->flash_id & FLASH_VENDMASK)
 	{
 		case FLASH_MAN_AMD:	printf ("AMD ");		break;
 		case FLASH_MAN_FUJ:	printf ("FUJITSU ");		break;
 		case FLASH_MAN_BM:	printf ("BRIGHT MICRO ");	break;
 		default:		printf ("Unknown Vendor ");	break;
 	}

 	switch (info->flash_id & FLASH_TYPEMASK)
 	{
 		case FLASH_AM040:	printf ("29F040 or 29LV040 (4 Mbit, uniform sectors)\n");
 			break;
 		case FLASH_AM400B:	printf ("AM29LV400B (4 Mbit, bottom boot sect)\n");
 					break;
 		case FLASH_AM400T:	printf ("AM29LV400T (4 Mbit, top boot sector)\n");
 					break;
 		case FLASH_AM800B:	printf ("AM29LV800B (8 Mbit, bottom boot sect)\n");
 					break;
 		case FLASH_AM800T:	printf ("AM29LV800T (8 Mbit, top boot sector)\n");
 					break;
 		case FLASH_AM160B:	printf ("AM29LV160B (16 Mbit, bottom boot sect)\n");
 					break;
 		case FLASH_AM160T:	printf ("AM29LV160T (16 Mbit, top boot sector)\n");
 					break;
 		case FLASH_AM320B:	printf ("AM29LV320B (32 Mbit, bottom boot sect)\n");
 					break;
 		case FLASH_AM320T:	printf ("AM29LV320T (32 Mbit, top boot sector)\n");
 					break;
 		default:		printf ("Unknown Chip Type\n");
 					break;
 	}

 	if (info->size >> 20) {
 	    printf ("  Size: %ld MB in %d Sectors\n",
 	    	info->size >> 20,
 		info->sector_count);
 	} else {
 	    printf ("  Size: %ld KB in %d Sectors\n",
 	    	info->size >> 10,
 		info->sector_count);
 	}

 	puts ("  Sector Start Addresses:");

 	for (i=0; i<info->sector_count; ++i)
 	{
 		if ((i % 5) == 0)
 		{
 			puts ("\n   ");
 		}

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

 	putc ('\n');
 	return;
 }
 /*-----------------------------------------------------------------------
  */

 /*
  * The following code cannot be run from FLASH!
  */

 static ulong flash_get_size (vu_long *addr, flash_info_t *info)
 {
 	short i;
 	volatile unsigned char *caddr;
 	char value;

 	caddr = (volatile unsigned char *)addr ;

 	/* Write auto select command: read Manufacturer ID */

 #if 0
 	printf("Base address is: %08x\n", caddr);
 #endif

 	caddr[0x0555] = 0xAA;
 	caddr[0x02AA] = 0x55;
 	caddr[0x0555] = 0x90;

 	value = caddr[0];

 #if 0
 	printf("Manufact ID: %02x\n", value);
 #endif
 	switch (value)
 	{
 		case 0x01: /*AMD_MANUFACT*/
 			info->flash_id = FLASH_MAN_AMD;
 		break;

 		case 0x04: /*FUJ_MANUFACT*/
 			info->flash_id = FLASH_MAN_FUJ;
 		break;

 		default:
 			info->flash_id = FLASH_UNKNOWN;
 			info->sector_count = 0;
 			info->size = 0;
 			break;
 	}

 	value = caddr[1];			/* device ID		*/
 #if 0
 	printf("Device ID: %02x\n", value);
 #endif
 	switch (value)
 	{
 		case AMD_ID_LV040B:
 			info->flash_id += FLASH_AM040;
 			info->sector_count = 8;
 			info->size = 0x00080000;
 			break;				/* => 512Kb 		*/

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

 	}

 	flash_get_offsets ((ulong)addr, &flash_info[0]);

 	/* 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 */
 		caddr = (volatile unsigned char *)(info->start[i]);
 		info->protect[i] = caddr[2] & 1;
 	}

 	/*
 	 * Prevent writes to uninitialized FLASH.
 	 */
 	if (info->flash_id != FLASH_UNKNOWN)
 	{
 		caddr = (volatile unsigned char *)info->start[0];
 		*caddr = 0xF0;	/* reset bank */
 	}

 	return (info->size);
 }


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

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

 	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_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;

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

 	addr[0x0555] = 0xAA;
 	addr[0x02AA] = 0x55;
 	addr[0x0555] = 0x80;
 	addr[0x0555] = 0xAA;
 	addr[0x02AA] = 0x55;

 	/* Start erase on unprotected sectors */
 	for (sect = s_first; sect<=s_last; sect++) {
 		if (info->protect[sect] == 0) {	/* not protected */
 			addr = (volatile unsigned char *)(info->start[sect]);
 			addr[0] = 0x30;
 			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 = (volatile unsigned char *)(info->start[l_sect]);

 	while ((addr[0] & 0xFF) != 0xFF)
 	{
 		if ((now = get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
 			printf ("Timeout\n");
 			return 1;
 		}
 		/* show that we're waiting */
 		if ((now - last) > 1000) {	/* every second */
 			putc ('.');
 			last = now;
 		}
 	}

 DONE:
 	/* reset to read mode */
 	addr = (volatile unsigned char *)info->start[0];

 	addr[0] = 0xF0;	/* 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 unsigned char *addr = (volatile unsigned char*)(info->start[0]),
 				*cdest,*cdata;
 	ulong start;
 	int flag, count = 4 ;

 	cdest = (volatile unsigned char *)dest ;
 	cdata = (volatile unsigned char *)&data ;

 	/* Check if Flash is (sufficiently) erased */
 	if ((*((vu_long *)dest) & data) != data) {
 		return (2);
 	}

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

 	    addr[0x0555] = 0xAA;
 	    addr[0x02AA] = 0x55;
 	    addr[0x0555] = 0xA0;

 	    *cdest = *cdata;

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

 	    /* data polling for D7 */
 	    start = get_timer (0);
 	    while ((*cdest ^ *cdata) & 0x80)
 	    {
 		if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
 			return (1);
 		}
 	    }

 	    cdata++ ;
 	    cdest++ ;
 	}
 	return (0);
 }

 /*-----------------------------------------------------------------------
  */
	/*
	* (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 <mpc8xx.h>

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

	/*-----------------------------------------------------------------------
	* Functions
	*/
	static ulong flash_get_size (vu_long addr, flash_info_t info);
	static int write_word (flash_info_t *info, ulong dest, ulong data);
	static void flash_get_offsets (ulong base, flash_info_t *info);

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

	unsigned long flash_init (void)
	{
	unsigned long size_b0, size_b1;
	int i;

	/* Init: no FLASHes known */
	for (i=0; i < CFG_MAX_FLASH_BANKS; ++i)
	flash_info[i].flash_id = FLASH_UNKNOWN;

	/* Detect size */
	size_b0 = flash_get_size((vu_long *)CFG_FLASH_BASE, &flash_info[0]);

	/* Setup offsets */
	flash_get_offsets (CFG_FLASH_BASE, &flash_info[0]);

	#if CFG_MONITOR_BASE >= CFG_FLASH_BASE
	/* Monitor protection ON by default */
	flash_protect(FLAG_PROTECT_SET,
	CFG_MONITOR_BASE,
	CFG_MONITOR_BASE+monitor_flash_len-1,
	&flash_info[0]);
	#endif

	size_b1 = 0 ;

	flash_info[1].flash_id = FLASH_UNKNOWN;
	flash_info[1].sector_count = -1;

	flash_info[0].size = size_b0;
	flash_info[1].size = size_b1;

	return (size_b0 + size_b1);
	}

	/*-----------------------------------------------------------------------
	* Fix this to support variable sector sizes
	*/
	static void flash_get_offsets (ulong base, flash_info_t *info)
	{
	int i;

	/* set up sector start address table */
	if ((info->flash_id & FLASH_TYPEMASK) == FLASH_AM040) {
	/* set sector offsets for bottom boot block type */
	for (i = 0; i < info->sector_count; i++)
	info->start[i] = base + (i * 0x00010000);
	}
	}

	/*-----------------------------------------------------------------------
	*/
	void flash_print_info (flash_info_t *info)
	{
	int i;

	if (info->flash_id == FLASH_UNKNOWN)
	{
	puts ("missing or unknown FLASH type\n");
	return;
	}

	switch (info->flash_id & FLASH_VENDMASK)
	{
	case FLASH_MAN_AMD: printf ("AMD "); break;
	case FLASH_MAN_FUJ: printf ("FUJITSU "); break;
	case FLASH_MAN_BM: printf ("BRIGHT MICRO "); break;
	default: printf ("Unknown Vendor "); break;
	}

	switch (info->flash_id & FLASH_TYPEMASK)
	{
	case FLASH_AM040: printf ("29F040 or 29LV040 (4 Mbit, uniform sectors)\n");
	break;
	case FLASH_AM400B: printf ("AM29LV400B (4 Mbit, bottom boot sect)\n");
	break;
	case FLASH_AM400T: printf ("AM29LV400T (4 Mbit, top boot sector)\n");
	break;
	case FLASH_AM800B: printf ("AM29LV800B (8 Mbit, bottom boot sect)\n");
	break;
	case FLASH_AM800T: printf ("AM29LV800T (8 Mbit, top boot sector)\n");
	break;
	case FLASH_AM160B: printf ("AM29LV160B (16 Mbit, bottom boot sect)\n");
	break;
	case FLASH_AM160T: printf ("AM29LV160T (16 Mbit, top boot sector)\n");
	break;
	case FLASH_AM320B: printf ("AM29LV320B (32 Mbit, bottom boot sect)\n");
	break;
	case FLASH_AM320T: printf ("AM29LV320T (32 Mbit, top boot sector)\n");
	break;
	default: printf ("Unknown Chip Type\n");
	break;
	}

	if (info->size >> 20) {
	printf (" Size: %ld MB in %d Sectors\n",
	info->size >> 20,
	info->sector_count);
	} else {
	printf (" Size: %ld KB in %d Sectors\n",
	info->size >> 10,
	info->sector_count);
	}

	puts (" Sector Start Addresses:");

	for (i=0; i<info->sector_count; ++i)
	{
	if ((i % 5) == 0)
	{
	puts ("\n ");
	}

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

	putc ('\n');
	return;
	}
	/*-----------------------------------------------------------------------
	*/

	/*
	* The following code cannot be run from FLASH!
	*/

	static ulong flash_get_size (vu_long addr, flash_info_t info)
	{
	short i;
	volatile unsigned char *caddr;
	char value;

	caddr = (volatile unsigned char *)addr ;

	/* Write auto select command: read Manufacturer ID */

	#if 0
	printf("Base address is: %08x\n", caddr);
	#endif

	caddr[0x0555] = 0xAA;
	caddr[0x02AA] = 0x55;
	caddr[0x0555] = 0x90;

	value = caddr[0];

	#if 0
	printf("Manufact ID: %02x\n", value);
	#endif
	switch (value)
	{
	case 0x01: /AMD_MANUFACT/
	info->flash_id = FLASH_MAN_AMD;
	break;

	case 0x04: /FUJ_MANUFACT/
	info->flash_id = FLASH_MAN_FUJ;
	break;

	default:
	info->flash_id = FLASH_UNKNOWN;
	info->sector_count = 0;
	info->size = 0;
	break;
	}

	value = caddr[1]; /* device ID */
	#if 0
	printf("Device ID: %02x\n", value);
	#endif
	switch (value)
	{
	case AMD_ID_LV040B:
	info->flash_id += FLASH_AM040;
	info->sector_count = 8;
	info->size = 0x00080000;
	break; /* => 512Kb */

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

	}

	flash_get_offsets ((ulong)addr, &flash_info[0]);

	/* 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 */
	caddr = (volatile unsigned char *)(info->start[i]);
	info->protect[i] = caddr[2] & 1;
	}

	/*
	* Prevent writes to uninitialized FLASH.
	*/
	if (info->flash_id != FLASH_UNKNOWN)
	{
	caddr = (volatile unsigned char *)info->start[0];
	caddr = 0xF0; / reset bank */
	}

	return (info->size);
	}


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

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

	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_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;

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

	addr[0x0555] = 0xAA;
	addr[0x02AA] = 0x55;
	addr[0x0555] = 0x80;
	addr[0x0555] = 0xAA;
	addr[0x02AA] = 0x55;

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
	if (info->protect[sect] == 0) { /* not protected */
	addr = (volatile unsigned char *)(info->start[sect]);
	addr[0] = 0x30;
	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 = (volatile unsigned char *)(info->start[l_sect]);

	while ((addr[0] & 0xFF) != 0xFF)
	{
	if ((now = get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
	printf ("Timeout\n");
	return 1;
	}
	/* show that we're waiting */
	if ((now - last) > 1000) { /* every second */
	putc ('.');
	last = now;
	}
	}

	DONE:
	/* reset to read mode */
	addr = (volatile unsigned char *)info->start[0];

	addr[0] = 0xF0; /* 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 unsigned char addr = (volatile unsigned char)(info->start[0]),
	cdest,cdata;
	ulong start;
	int flag, count = 4 ;

	cdest = (volatile unsigned char *)dest ;
	cdata = (volatile unsigned char *)&data ;

	/* Check if Flash is (sufficiently) erased */
	if ((((vu_long )dest) & data) != data) {
	return (2);
	}

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

	addr[0x0555] = 0xAA;
	addr[0x02AA] = 0x55;
	addr[0x0555] = 0xA0;

	cdest = cdata;

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

	/* data polling for D7 */
	start = get_timer (0);
	while ((cdest ^ cdata) & 0x80)
	{
	if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
	return (1);
	}
	}

	cdata++ ;
	cdest++ ;
	}
	return (0);
	}

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