Initial revision

1 files changed, 755 insertions, 0 deletions

diff --git a/board/ppmc8260/strataflash.c b/board/ppmc8260/strataflash.c
new file mode 100644
index 0000000..bb21848
--- /dev/null
+++ b/board/ppmc8260/strataflash.c
@@ -0,0 +1,755 @@
+/*
+ * (C) Copyright 2002
+ * Brad Kemp, Seranoa Networks, Brad.Kemp@seranoa.com
+ *
+ * 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 <mpc8260.h>
+#include <asm/processor.h>
+
+#undef  DEBUG_FLASH
+/*
+ * This file implements a Common Flash Interface (CFI) driver for U-Boot.
+ * The width of the port and the width of the chips are determined at initialization.
+ * These widths are used to calculate the address for access CFI data structures.
+ * It has been tested on an Intel Strataflash implementation.
+ *
+ * References
+ * JEDEC Standard JESD68 - Common Flash Interface (CFI)
+ * JEDEC Standard JEP137-A Common Flash Interface (CFI) ID Codes
+ * Intel Application Note 646 Common Flash Interface (CFI) and Command Sets
+ * Intel 290667-008 3 Volt Intel StrataFlash Memory datasheet
+ *
+ * TODO
+ * Use Primary Extended Query table (PRI) and Alternate Algorithm Query Table (ALT) to determine if protection is available
+ * Add support for other command sets Use the PRI and ALT to determine command set
+ * Verify erase and program timeouts.
+ */
+
+#define FLASH_CMD_CFI			0x98
+#define FLASH_CMD_READ_ID		0x90
+#define FLASH_CMD_RESET			0xff
+#define FLASH_CMD_BLOCK_ERASE		0x20
+#define FLASH_CMD_ERASE_CONFIRM		0xD0
+#define FLASH_CMD_WRITE			0x40
+#define FLASH_CMD_PROTECT		0x60
+#define FLASH_CMD_PROTECT_SET		0x01
+#define FLASH_CMD_PROTECT_CLEAR		0xD0
+#define FLASH_CMD_CLEAR_STATUS		0x50
+#define FLASH_CMD_WRITE_TO_BUFFER       0xE8
+#define FLASH_CMD_WRITE_BUFFER_CONFIRM  0xD0
+
+#define FLASH_STATUS_DONE		0x80
+#define FLASH_STATUS_ESS		0x40
+#define FLASH_STATUS_ECLBS		0x20
+#define FLASH_STATUS_PSLBS		0x10
+#define FLASH_STATUS_VPENS		0x08
+#define FLASH_STATUS_PSS		0x04
+#define FLASH_STATUS_DPS		0x02
+#define FLASH_STATUS_R			0x01
+#define FLASH_STATUS_PROTECT		0x01
+
+#define FLASH_OFFSET_CFI		0x55
+#define FLASH_OFFSET_CFI_RESP		0x10
+#define FLASH_OFFSET_WTOUT		0x1F
+#define FLASH_OFFSET_WBTOUT             0x20
+#define FLASH_OFFSET_ETOUT		0x21
+#define FLASH_OFFSET_CETOUT             0x22
+#define FLASH_OFFSET_WMAX_TOUT		0x23
+#define FLASH_OFFSET_WBMAX_TOUT         0x24
+#define FLASH_OFFSET_EMAX_TOUT		0x25
+#define FLASH_OFFSET_CEMAX_TOUT         0x26
+#define FLASH_OFFSET_SIZE		0x27
+#define FLASH_OFFSET_INTERFACE          0x28
+#define FLASH_OFFSET_BUFFER_SIZE        0x2A
+#define FLASH_OFFSET_NUM_ERASE_REGIONS	0x2C
+#define FLASH_OFFSET_ERASE_REGIONS	0x2D
+#define FLASH_OFFSET_PROTECT		0x02
+#define FLASH_OFFSET_USER_PROTECTION    0x85
+#define FLASH_OFFSET_INTEL_PROTECTION   0x81
+
+
+#define FLASH_MAN_CFI			0x01000000
+
+
+
+
+typedef union {
+	unsigned char c;
+	unsigned short w;
+	unsigned long l;
+} cfiword_t;
+
+typedef union {
+	unsigned char * cp;
+	unsigned short *wp;
+	unsigned long *lp;
+} cfiptr_t;
+
+#define NUM_ERASE_REGIONS 4
+
+flash_info_t	flash_info[CFG_MAX_FLASH_BANKS]; /* info for FLASH chips	*/
+
+
+/*-----------------------------------------------------------------------
+ * Functions
+ */
+
+
+
+static void flash_add_byte(flash_info_t *info, cfiword_t * cword, uchar c);
+static void flash_make_cmd(flash_info_t * info, uchar cmd, void * cmdbuf);
+static void flash_write_cmd(flash_info_t * info, int sect, uchar offset, uchar cmd);
+static int flash_isequal(flash_info_t * info, int sect, uchar offset, uchar cmd);
+static int flash_isset(flash_info_t * info, int sect, uchar offset, uchar cmd);
+static int flash_detect_cfi(flash_info_t * info);
+static ulong flash_get_size (ulong base, int banknum);
+static int flash_write_cfiword (flash_info_t *info, ulong dest, cfiword_t cword);
+static int flash_full_status_check(flash_info_t * info, ulong sector, ulong tout, char * prompt);
+#ifdef CFG_FLASH_USE_BUFFER_WRITE
+static int flash_write_cfibuffer(flash_info_t * info, ulong dest, uchar * cp, int len);
+#endif
+/*-----------------------------------------------------------------------
+ * create an address based on the offset and the port width
+ */
+inline uchar * flash_make_addr(flash_info_t * info, int sect, int offset)
+{
+	return ((uchar *)(info->start[sect] + (offset * info->portwidth)));
+}
+/*-----------------------------------------------------------------------
+ * read a character at a port width address
+ */
+inline uchar flash_read_uchar(flash_info_t * info, uchar offset)
+{
+	uchar *cp;
+	cp = flash_make_addr(info, 0, offset);
+	return (cp[info->portwidth - 1]);
+}
+
+/*-----------------------------------------------------------------------
+ * read a short word by swapping for ppc format.
+ */
+ushort flash_read_ushort(flash_info_t * info, int sect,  uchar offset)
+{
+    uchar * addr;
+
+    addr = flash_make_addr(info, sect, offset);
+    return ((addr[(2*info->portwidth) - 1] << 8) | addr[info->portwidth - 1]);
+
+}
+
+/*-----------------------------------------------------------------------
+ * read a long word by picking the least significant byte of each maiximum
+ * port size word. Swap for ppc format.
+ */
+ulong flash_read_long(flash_info_t * info, int sect,  uchar offset)
+{
+    uchar * addr;
+
+    addr = flash_make_addr(info, sect, offset);
+    return ( (addr[(2*info->portwidth) - 1] << 24 ) | (addr[(info->portwidth) -1] << 16) |
+	    (addr[(4*info->portwidth) - 1] << 8) | addr[(3*info->portwidth) - 1]);
+
+}
+
+/*-----------------------------------------------------------------------
+ */
+unsigned long flash_init (void)
+{
+	unsigned long size;
+	int i;
+	unsigned long  address;
+
+
+	/* The flash is positioned back to back, with the demultiplexing of the chip
+	 * based on the A24 address line.
+	 *
+	 */
+
+	address = CFG_FLASH_BASE;
+	size = 0;
+
+
+	/* Init: no FLASHes known */
+	for (i=0; i<CFG_MAX_FLASH_BANKS; ++i) {
+		flash_info[i].flash_id = FLASH_UNKNOWN;
+		size += flash_info[i].size = flash_get_size(address, i);
+		address += CFG_FLASH_INCREMENT;
+		if (flash_info[0].flash_id == FLASH_UNKNOWN) {
+			printf ("## Unknown FLASH on Bank %d - Size = 0x%08lx = %ld MB\n",i,
+				flash_info[0].size, flash_info[i].size<<20);
+		}
+	}
+
+	/* Monitor protection ON by default */
+#if (CFG_MONITOR_BASE >= CFG_FLASH_BASE)
+	for(i=0; flash_info[0].start[i] < CFG_MONITOR_BASE+CFG_MONITOR_LEN-1; i++)
+		(void)flash_real_protect(&flash_info[0], i, 1);
+#endif
+
+	return (size);
+}
+
+/*-----------------------------------------------------------------------
+ */
+int flash_erase (flash_info_t *info, int s_first, int s_last)
+{
+	int rcode = 0;
+	int prot;
+	int sect;
+
+	if( info->flash_id != FLASH_MAN_CFI) {
+		printf ("Can't erase unknown flash type - aborted\n");
+		return 1;
+	}
+	if ((s_first < 0) || (s_first > s_last)) {
+		printf ("- no sectors to erase\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");
+	}
+
+
+	for (sect = s_first; sect<=s_last; sect++) {
+		if (info->protect[sect] == 0) { /* not protected */
+			flash_write_cmd(info, sect, 0, FLASH_CMD_CLEAR_STATUS);
+			flash_write_cmd(info, sect, 0, FLASH_CMD_BLOCK_ERASE);
+			flash_write_cmd(info, sect, 0, FLASH_CMD_ERASE_CONFIRM);
+
+			if(flash_full_status_check(info, sect, info->erase_blk_tout, "erase")) {
+				rcode = 1;
+			} else
+				printf(".");
+		}
+	}
+	printf (" done\n");
+	return rcode;
+}
+
+/*-----------------------------------------------------------------------
+ */
+void flash_print_info  (flash_info_t *info)
+{
+	int i;
+
+	if (info->flash_id != FLASH_MAN_CFI) {
+		printf ("missing or unknown FLASH type\n");
+		return;
+	}
+
+	printf("CFI conformant FLASH (%d x %d)",
+	       (info->portwidth	 << 3 ), (info->chipwidth  << 3 ));
+	printf ("  Size: %ld MB in %d Sectors\n",
+		info->size >> 20, info->sector_count);
+	printf(" Erase timeout %ld ms, write timeout %ld ms, buffer write timeout %ld ms, buffer size %d\n",
+	       info->erase_blk_tout, info->write_tout, info->buffer_write_tout, info->buffer_size);
+
+	printf ("  Sector Start Addresses:");
+	for (i=0; i<info->sector_count; ++i) {
+		if ((i % 5) == 0)
+			printf ("\n");
+		printf (" %08lX%5s",
+			info->start[i],
+			info->protect[i] ? " (RO)" : " "
+			);
+	}
+	printf ("\n");
+	return;
+}
+
+/*-----------------------------------------------------------------------
+ * 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 wp;
+	ulong cp;
+	int aln;
+	cfiword_t cword;
+	int i, rc;
+
+	/* get lower aligned address */
+	wp = (addr & ~(info->portwidth - 1));
+
+	/* handle unaligned start */
+	if((aln = addr - wp) != 0) {
+		cword.l = 0;
+		cp = wp;
+		for(i=0;i<aln; ++i, ++cp)
+			flash_add_byte(info, &cword, (*(uchar *)cp));
+
+		for(; (i< info->portwidth) && (cnt > 0) ; i++) {
+			flash_add_byte(info, &cword, *src++);
+			cnt--;
+			cp++;
+		}
+		for(; (cnt == 0) && (i < info->portwidth); ++i, ++cp)
+			flash_add_byte(info, &cword, (*(uchar *)cp));
+		if((rc = flash_write_cfiword(info, wp, cword)) != 0)
+			return rc;
+		wp = cp;
+	}
+
+#ifdef CFG_FLASH_USE_BUFFER_WRITE
+	while(cnt >= info->portwidth) {
+		i = info->buffer_size > cnt? cnt: info->buffer_size;
+		if((rc = flash_write_cfibuffer(info, wp, src,i)) != ERR_OK)
+			return rc;
+		wp += i;
+		src += i;
+		cnt -=i;
+	}
+#else
+	/* handle the aligned part */
+	while(cnt >= info->portwidth) {
+		cword.l = 0;
+		for(i = 0; i < info->portwidth; i++) {
+			flash_add_byte(info, &cword, *src++);
+		}
+		if((rc = flash_write_cfiword(info, wp, cword)) != 0)
+			return rc;
+		wp += info->portwidth;
+		cnt -= info->portwidth;
+	}
+#endif /* CFG_FLASH_USE_BUFFER_WRITE */
+	if (cnt == 0) {
+		return (0);
+	}
+
+	/*
+	 * handle unaligned tail bytes
+	 */
+	cword.l = 0;
+	for (i=0, cp=wp; (i<info->portwidth) && (cnt>0); ++i, ++cp) {
+		flash_add_byte(info, &cword, *src++);
+		--cnt;
+	}
+	for (; i<info->portwidth; ++i, ++cp) {
+		flash_add_byte(info, & cword, (*(uchar *)cp));
+	}
+
+	return flash_write_cfiword(info, wp, cword);
+}
+
+/*-----------------------------------------------------------------------
+ */
+int flash_real_protect(flash_info_t *info, long sector, int prot)
+{
+	int retcode = 0;
+
+	flash_write_cmd(info, sector, 0, FLASH_CMD_CLEAR_STATUS);
+	flash_write_cmd(info, sector, 0, FLASH_CMD_PROTECT);
+	if(prot)
+		flash_write_cmd(info, sector, 0, FLASH_CMD_PROTECT_SET);
+	else
+		flash_write_cmd(info, sector, 0, FLASH_CMD_PROTECT_CLEAR);
+
+	if((retcode = flash_full_status_check(info, sector, info->erase_blk_tout,
+					 prot?"protect":"unprotect")) == 0) {
+
+		info->protect[sector] = prot;
+		/* Intel's unprotect unprotects all locking */
+		if(prot == 0) {
+			int i;
+			for(i = 0 ; i<info->sector_count; i++) {
+				if(info->protect[i])
+					flash_real_protect(info, i, 1);
+			}
+		}
+	}
+
+	return retcode;
+}
+/*-----------------------------------------------------------------------
+ *  wait for XSR.7 to be set. Time out with an error if it does not.
+ *  This routine does not set the flash to read-array mode.
+ */
+static int flash_status_check(flash_info_t * info, ulong sector, ulong tout, char * prompt)
+{
+	ulong start;
+
+	/* Wait for command completion */
+	start = get_timer (0);
+	while(!flash_isset(info, sector, 0, FLASH_STATUS_DONE)) {
+		if (get_timer(start) > info->erase_blk_tout) {
+			printf("Flash %s timeout at address %lx\n", prompt, info->start[sector]);
+			flash_write_cmd(info, sector, 0, FLASH_CMD_RESET);
+			return ERR_TIMOUT;
+		}
+	}
+	return ERR_OK;
+}
+/*-----------------------------------------------------------------------
+ * Wait for XSR.7 to be set, if it times out print an error, otherwise do a full status check.
+ * This routine sets the flash to read-array mode.
+ */
+static int flash_full_status_check(flash_info_t * info, ulong sector, ulong tout, char * prompt)
+{
+	int retcode;
+	retcode = flash_status_check(info, sector, tout, prompt);
+	if((retcode == ERR_OK) && !flash_isequal(info,sector, 0, FLASH_STATUS_DONE)) {
+		retcode = ERR_INVAL;
+		printf("Flash %s error at address %lx\n", prompt,info->start[sector]);
+		if(flash_isset(info, sector, 0, FLASH_STATUS_ECLBS | FLASH_STATUS_PSLBS)){
+			printf("Command Sequence Error.\n");
+		} else if(flash_isset(info, sector, 0, FLASH_STATUS_ECLBS)){
+			printf("Block Erase Error.\n");
+		        retcode = ERR_NOT_ERASED;
+		} else if (flash_isset(info, sector, 0, FLASH_STATUS_PSLBS)) {
+			printf("Locking Error\n");
+		}
+		if(flash_isset(info, sector, 0, FLASH_STATUS_DPS)){
+			printf("Block locked.\n");
+			retcode = ERR_PROTECTED;
+		}
+		if(flash_isset(info, sector, 0, FLASH_STATUS_VPENS))
+			printf("Vpp Low Error.\n");
+	}
+	flash_write_cmd(info, sector, 0, FLASH_CMD_RESET);
+	return retcode;
+}
+/*-----------------------------------------------------------------------
+ */
+static void flash_add_byte(flash_info_t *info, cfiword_t * cword, uchar c)
+{
+	switch(info->portwidth) {
+	case FLASH_CFI_8BIT:
+		cword->c = c;
+		break;
+	case FLASH_CFI_16BIT:
+		cword->w = (cword->w << 8) | c;
+		break;
+	case FLASH_CFI_32BIT:
+		cword->l = (cword->l << 8) | c;
+	}
+}
+
+
+/*-----------------------------------------------------------------------
+ * make a proper sized command based on the port and chip widths
+ */
+static void flash_make_cmd(flash_info_t * info, uchar cmd, void * cmdbuf)
+{
+	int i;
+	uchar *cp = (uchar *)cmdbuf;
+	for(i=0; i< info->portwidth; i++)
+		*cp++ = ((i+1) % info->chipwidth) ? '\0':cmd;
+}
+
+/*
+ * Write a proper sized command to the correct address
+ */
+static void flash_write_cmd(flash_info_t * info, int sect, uchar offset, uchar cmd)
+{
+
+	volatile cfiptr_t addr;
+	cfiword_t cword;
+	addr.cp = flash_make_addr(info, sect, offset);
+	flash_make_cmd(info, cmd, &cword);
+	switch(info->portwidth) {
+	case FLASH_CFI_8BIT:
+		*addr.cp = cword.c;
+		break;
+	case FLASH_CFI_16BIT:
+		*addr.wp = cword.w;
+		break;
+	case FLASH_CFI_32BIT:
+		*addr.lp = cword.l;
+		break;
+	}
+}
+
+/*-----------------------------------------------------------------------
+ */
+static int flash_isequal(flash_info_t * info, int sect, uchar offset, uchar cmd)
+{
+	cfiptr_t cptr;
+	cfiword_t cword;
+	int retval;
+	cptr.cp = flash_make_addr(info, sect, offset);
+	flash_make_cmd(info, cmd, &cword);
+	switch(info->portwidth) {
+	case FLASH_CFI_8BIT:
+		retval = (cptr.cp[0] == cword.c);
+		break;
+	case FLASH_CFI_16BIT:
+		retval = (cptr.wp[0] == cword.w);
+		break;
+	case FLASH_CFI_32BIT:
+		retval = (cptr.lp[0] == cword.l);
+		break;
+	default:
+		retval = 0;
+		break;
+	}
+	return retval;
+}
+/*-----------------------------------------------------------------------
+ */
+static int flash_isset(flash_info_t * info, int sect, uchar offset, uchar cmd)
+{
+	cfiptr_t cptr;
+	cfiword_t cword;
+	int retval;
+	cptr.cp = flash_make_addr(info, sect, offset);
+	flash_make_cmd(info, cmd, &cword);
+	switch(info->portwidth) {
+	case FLASH_CFI_8BIT:
+		retval = ((cptr.cp[0] & cword.c) == cword.c);
+		break;
+	case FLASH_CFI_16BIT:
+		retval = ((cptr.wp[0] & cword.w) == cword.w);
+		break;
+	case FLASH_CFI_32BIT:
+		retval = ((cptr.lp[0] & cword.l) == cword.l);
+		break;
+	default:
+		retval = 0;
+		break;
+	}
+	return retval;
+}
+
+/*-----------------------------------------------------------------------
+ * detect if flash is compatible with the Common Flash Interface (CFI)
+ * http://www.jedec.org/download/search/jesd68.pdf
+ *
+*/
+static int flash_detect_cfi(flash_info_t * info)
+{
+
+	for(info->portwidth=FLASH_CFI_8BIT; info->portwidth <= FLASH_CFI_32BIT;
+	    info->portwidth <<= 1) {
+		for(info->chipwidth =FLASH_CFI_BY8;
+		    info->chipwidth <= info->portwidth;
+		    info->chipwidth <<= 1) {
+			flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
+			flash_write_cmd(info, 0, FLASH_OFFSET_CFI, FLASH_CMD_CFI);
+			if(flash_isequal(info, 0, FLASH_OFFSET_CFI_RESP,'Q') &&
+			   flash_isequal(info, 0, FLASH_OFFSET_CFI_RESP + 1, 'R') &&
+			   flash_isequal(info, 0, FLASH_OFFSET_CFI_RESP + 2, 'Y'))
+				return 1;
+		}
+	}
+	return 0;
+}
+/*
+ * The following code cannot be run from FLASH!
+ *
+ */
+static ulong flash_get_size (ulong base, int banknum)
+{
+	flash_info_t * info = &flash_info[banknum];
+	int i, j;
+	int sect_cnt;
+	unsigned long sector;
+	unsigned long tmp;
+	int size_ratio;
+	uchar num_erase_regions;
+	int  erase_region_size;
+	int  erase_region_count;
+
+	info->start[0] = base;
+
+	if(flash_detect_cfi(info)){
+		size_ratio = info->portwidth / info->chipwidth;
+		num_erase_regions = flash_read_uchar(info, FLASH_OFFSET_NUM_ERASE_REGIONS);
+#ifdef DEBUG_FLASH
+		printf("found %d erase regions\n", num_erase_regions);
+#endif
+		sect_cnt = 0;
+		sector = base;
+		for(i = 0 ; i < num_erase_regions; i++) {
+			if(i > NUM_ERASE_REGIONS) {
+				printf("%d erase regions found, only %d used\n",
+				       num_erase_regions, NUM_ERASE_REGIONS);
+				break;
+			}
+			tmp = flash_read_long(info, 0, FLASH_OFFSET_ERASE_REGIONS);
+			erase_region_size = (tmp & 0xffff)? ((tmp & 0xffff) * 256): 128;
+			tmp >>= 16;
+			erase_region_count = (tmp & 0xffff) +1;
+			for(j = 0; j< erase_region_count; j++) {
+				info->start[sect_cnt] = sector;
+				sector += (erase_region_size * size_ratio);
+				info->protect[sect_cnt] = flash_isset(info, sect_cnt, FLASH_OFFSET_PROTECT, FLASH_STATUS_PROTECT);
+				sect_cnt++;
+			}
+		}
+
+		info->sector_count = sect_cnt;
+		/* multiply the size by the number of chips */
+		info->size = (1 << flash_read_uchar(info, FLASH_OFFSET_SIZE)) * size_ratio;
+		info->buffer_size = (1 << flash_read_ushort(info, 0, FLASH_OFFSET_BUFFER_SIZE));
+		tmp = 1 << flash_read_uchar(info, FLASH_OFFSET_ETOUT);
+		info->erase_blk_tout = (tmp * (1 << flash_read_uchar(info, FLASH_OFFSET_EMAX_TOUT)));
+		tmp = 1 << flash_read_uchar(info, FLASH_OFFSET_WBTOUT);
+		info->buffer_write_tout = (tmp * (1 << flash_read_uchar(info, FLASH_OFFSET_WBMAX_TOUT)));
+		tmp = 1 << flash_read_uchar(info, FLASH_OFFSET_WTOUT);
+		info->write_tout = (tmp * (1 << flash_read_uchar(info, FLASH_OFFSET_WMAX_TOUT)))/ 1000;
+		info->flash_id = FLASH_MAN_CFI;
+	}
+
+	flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
+	return(info->size);
+}
+
+
+/*-----------------------------------------------------------------------
+ */
+static int flash_write_cfiword (flash_info_t *info, ulong dest, cfiword_t cword)
+{
+
+	cfiptr_t ctladdr;
+	cfiptr_t cptr;
+	int flag;
+
+	ctladdr.cp = flash_make_addr(info, 0, 0);
+	cptr.cp = (uchar *)dest;
+
+
+	/* Check if Flash is (sufficiently) erased */
+	switch(info->portwidth) {
+	case FLASH_CFI_8BIT:
+		flag = ((cptr.cp[0] & cword.c) == cword.c);
+		break;
+	case FLASH_CFI_16BIT:
+		flag = ((cptr.wp[0] & cword.w) == cword.w);
+		break;
+	case FLASH_CFI_32BIT:
+		flag = ((cptr.lp[0] & cword.l)	== cword.l);
+		break;
+	default:
+		return 2;
+	}
+	if(!flag)
+		return 2;
+
+	/* Disable interrupts which might cause a timeout here */
+	flag = disable_interrupts();
+
+	flash_write_cmd(info, 0, 0, FLASH_CMD_CLEAR_STATUS);
+	flash_write_cmd(info, 0, 0, FLASH_CMD_WRITE);
+
+	switch(info->portwidth) {
+	case FLASH_CFI_8BIT:
+		cptr.cp[0] = cword.c;
+		break;
+	case FLASH_CFI_16BIT:
+		cptr.wp[0] = cword.w;
+		break;
+	case FLASH_CFI_32BIT:
+		cptr.lp[0] = cword.l;
+		break;
+	}
+
+	/* re-enable interrupts if necessary */
+	if(flag)
+		enable_interrupts();
+
+	return flash_full_status_check(info, 0, info->write_tout, "write");
+}
+
+#ifdef CFG_FLASH_USE_BUFFER_WRITE
+
+/* loop through the sectors from the highest address
+ * when the passed address is greater or equal to the sector address
+ * we have a match
+ */
+static int find_sector(flash_info_t *info, ulong addr)
+{
+	int sector;
+	for(sector = info->sector_count - 1; sector >= 0; sector--) {
+		if(addr >= info->start[sector])
+			break;
+	}
+	return sector;
+}
+
+static int flash_write_cfibuffer(flash_info_t * info, ulong dest, uchar * cp, int len)
+{
+
+	int sector;
+	int cnt;
+	int retcode;
+	volatile cfiptr_t src;
+	volatile cfiptr_t dst;
+
+	src.cp = cp;
+	dst.cp = (uchar *)dest;
+	sector = find_sector(info, dest);
+	flash_write_cmd(info, sector, 0, FLASH_CMD_CLEAR_STATUS);
+	flash_write_cmd(info, sector, 0, FLASH_CMD_WRITE_TO_BUFFER);
+	if((retcode = flash_status_check(info, sector, info->buffer_write_tout,
+					 "write to buffer")) == ERR_OK) {
+		switch(info->portwidth) {
+		case FLASH_CFI_8BIT:
+			cnt = len;
+			break;
+		case FLASH_CFI_16BIT:
+			cnt = len >> 1;
+			break;
+		case FLASH_CFI_32BIT:
+			cnt = len >> 2;
+			break;
+		default:
+			return ERR_INVAL;
+			break;
+		}
+		flash_write_cmd(info, sector, 0, (uchar)cnt-1);
+		while(cnt-- > 0) {
+			switch(info->portwidth) {
+			case FLASH_CFI_8BIT:
+				*dst.cp++ = *src.cp++;
+				break;
+			case FLASH_CFI_16BIT:
+				*dst.wp++ = *src.wp++;
+				break;
+			case FLASH_CFI_32BIT:
+				*dst.lp++ = *src.lp++;
+				break;
+			default:
+				return ERR_INVAL;
+				break;
+			}
+		}
+		flash_write_cmd(info, sector, 0, FLASH_CMD_WRITE_BUFFER_CONFIRM);
+		retcode = flash_full_status_check(info, sector, info->buffer_write_tout,
+					     "buffer write");
+	}
+	flash_write_cmd(info, sector, 0, FLASH_CMD_CLEAR_STATUS);
+	return retcode;
+}
+#endif /* CFG_USE_FLASH_BUFFER_WRITE */