Patch by Kurt Stremerch, 28 May 2004:
Add support for Exys XSEngine board

Some code cleanup.
diff --git a/board/xsengine/flash.c b/board/xsengine/flash.c
new file mode 100644
index 0000000..ac14bfe
--- /dev/null
+++ b/board/xsengine/flash.c
@@ -0,0 +1,565 @@
+/*
+ * (C) Copyright 2002
+ * Robert Schwebel, Pengutronix, <r.schwebel@pengutronix.de>
+ *
+ * (C) Copyright 2000-2004
+ * 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 <linux/byteorder/swab.h>
+
+#if defined CFG_JFFS_CUSTOM_PART
+#include <jffs2/jffs2.h>
+#endif
+
+#define SWAP(x)               __swab32(x)
+
+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);
+
+#if defined CFG_JFFS_CUSTOM_PART
+
+/*
+ * jffs2_part_info - get information about a JFFS2 partition
+ *
+ * @part_num: number of the partition you want to get info about
+ * @return:   struct part_info* in case of success, 0 if failure
+ */
+
+static struct part_info part;
+static int current_part = -1;
+
+struct part_info* jffs2_part_info(int part_num) {
+	void *jffs2_priv_saved = part.jffs2_priv;
+
+	printf("jffs2_part_info: part_num=%i\n",part_num);
+
+	if (current_part == part_num)
+		return &part;
+
+	/* u-boot partition                                                 */
+	if(part_num==0){
+		memset(&part, 0, sizeof(part));
+
+		part.offset=(char*)0x00000000;
+		part.size=256*1024;
+
+		/* Mark the struct as ready */
+		current_part = part_num;
+
+		printf("part.offset = 0x%08x\n",(unsigned int)part.offset);
+		printf("part.size   = 0x%08x\n",(unsigned int)part.size);
+	}
+
+	/* primary OS+firmware partition                                    */
+	if(part_num==1){
+		memset(&part, 0, sizeof(part));
+
+		part.offset=(char*)0x00040000;
+		part.size=1024*1024;
+
+		/* Mark the struct as ready */
+		current_part = part_num;
+
+		printf("part.offset = 0x%08x\n",(unsigned int)part.offset);
+		printf("part.size   = 0x%08x\n",(unsigned int)part.size);
+	}
+
+	/* secondary OS+firmware partition                                  */
+	if(part_num==2){
+		memset(&part, 0, sizeof(part));
+
+		part.offset=(char*)0x00140000;
+		part.size=8*1024*1024;
+
+		/* Mark the struct as ready */
+		current_part = part_num;
+
+		printf("part.offset = 0x%08x\n",(unsigned int)part.offset);
+		printf("part.size   = 0x%08x\n",(unsigned int)part.size);
+	}
+
+	if (current_part == part_num) {
+		part.usr_priv = &current_part;
+		part.jffs2_priv = jffs2_priv_saved;
+		return &part;
+	}
+
+	printf("jffs2_part_info: end of partition table\n");
+	return 0;
+}
+#endif
+
+
+/*-----------------------------------------------------------------------
+ */
+unsigned long flash_init (void)
+{
+	int i;
+	ulong size = 0;
+
+	for (i = 0; i < CFG_MAX_FLASH_BANKS; i++) {
+		switch (i) {
+		case 0:
+			flash_get_size ((long *) PHYS_FLASH_1, &flash_info[i]);
+			flash_get_offsets (PHYS_FLASH_1, &flash_info[i]);
+			break;
+		case 1:
+			flash_get_size ((long *) PHYS_FLASH_2, &flash_info[i]);
+			flash_get_offsets (PHYS_FLASH_2, &flash_info[i]);
+			break;
+		default:
+			panic ("configured too many flash banks!\n");
+			break;
+		}
+		size += flash_info[i].size;
+	}
+
+	/* Protect monitor and environment sectors */
+	flash_protect ( FLAG_PROTECT_SET,CFG_FLASH_BASE,CFG_FLASH_BASE + monitor_flash_len - 1,&flash_info[0] );
+	flash_protect ( FLAG_PROTECT_SET,CFG_ENV_ADDR,CFG_ENV_ADDR + CFG_ENV_SIZE - 1, &flash_info[0] );
+
+	return size;
+}
+
+/*-----------------------------------------------------------------------
+ */
+static void flash_get_offsets (ulong base, flash_info_t *info)
+{
+	int i;
+
+	if (info->flash_id == FLASH_UNKNOWN) return;
+
+	if ((info->flash_id & FLASH_VENDMASK) == FLASH_MAN_AMD) {
+		for (i = 0; i < info->sector_count; i++) {
+			info->start[i] = base + (i * PHYS_FLASH_SECT_SIZE);
+			info->protect[i] = 0;
+		}
+	}
+}
+
+/*-----------------------------------------------------------------------
+ */
+void flash_print_info  (flash_info_t *info)
+{
+	int i;
+
+	if (info->flash_id == FLASH_UNKNOWN) {
+		printf ("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;
+	default:		printf ("Unknown Vendor ");	break;
+	}
+
+	switch (info->flash_id & FLASH_TYPEMASK) {
+	case FLASH_AMLV128U:	printf ("AM29LV128ML (128Mbit, uniform sector size)\n");
+				break;
+	case FLASH_AMLV320U:	printf ("AM29LV320ML (32Mbit, uniform sector size)\n");
+				break;
+	case FLASH_AMLV640U:	printf ("AM29LV640ML (64Mbit, uniform sector size)\n");
+				break;
+	case FLASH_AMLV320B:	printf ("AM29LV320MB (32Mbit, bottom boot sect)\n");
+				break;
+	default:		printf ("Unknown Chip Type\n");
+				break;
+	}
+
+	printf ("  Size: %ld MB in %d Sectors\n",
+		info->size >> 20, info->sector_count);
+
+	printf ("  Sector Start Addresses:");
+	for (i=0; i<info->sector_count; ++i) {
+		if ((i % 5) == 0)
+			printf ("\n   ");
+		printf (" %08lX%s",
+			info->start[i],
+			info->protect[i] ? " (RO)" : "     "
+		);
+	}
+	printf ("\n");
+	return;
+}
+
+/*
+ * The following code cannot be run from FLASH!
+ */
+static ulong flash_get_size (vu_long *addr, flash_info_t *info)
+{
+	short i;
+	ulong value;
+	ulong base = (ulong)addr;
+
+	/* Write auto select command: read Manufacturer ID */
+	addr[0x0555] = 0x00AA00AA;
+	addr[0x02AA] = 0x00550055;
+	addr[0x0555] = 0x00900090;
+
+	value = addr[0];
+
+	debug ("Manuf. ID @ 0x%08lx: 0x%08lx\n", (ulong)addr, value);
+
+	switch (value) {
+	case AMD_MANUFACT:
+		debug ("Manufacturer: AMD\n");
+		info->flash_id = FLASH_MAN_AMD;
+		break;
+	case FUJ_MANUFACT:
+		debug ("Manufacturer: FUJITSU\n");
+		info->flash_id = FLASH_MAN_FUJ;
+		break;
+	default:
+		debug ("Manufacturer: *** unknown ***\n");
+		info->flash_id = FLASH_UNKNOWN;
+		info->sector_count = 0;
+		info->size = 0;
+		return (0);			/* no or unknown flash	*/
+	}
+
+	value = addr[1];			/* device ID		*/
+
+	debug ("Device ID @ 0x%08lx: 0x%08lx\n", (ulong)(&addr[1]), value);
+
+	switch (value) {
+
+	case AMD_ID_MIRROR:
+		debug ("Mirror Bit flash: addr[14] = %08lX  addr[15] = %08lX\n",
+			addr[14], addr[15]);
+		switch(addr[14]) {
+		case AMD_ID_LV128U_2:
+			if (addr[15] != AMD_ID_LV128U_3) {
+				debug ("Chip: AMLV128U -> unknown\n");
+				info->flash_id = FLASH_UNKNOWN;
+			} else {
+				debug ("Chip: AMLV128U\n");
+				info->flash_id += FLASH_AMLV128U;
+				info->sector_count = 256;
+				info->size = 0x02000000;
+			}
+			break;				/* => 32 MB	*/
+		case AMD_ID_LV640U_2:
+			if (addr[15] != AMD_ID_LV640U_3) {
+				debug ("Chip: AMLV640U -> unknown\n");
+				info->flash_id = FLASH_UNKNOWN;
+			} else {
+				debug ("Chip: AMLV640U\n");
+				info->flash_id += FLASH_AMLV640U;
+				info->sector_count = 128;
+				info->size = 0x01000000;
+			}
+			break;				/* => 16 MB	*/
+		case AMD_ID_LV320B_2:
+			if (addr[15] != AMD_ID_LV320B_3) {
+				debug ("Chip: AMLV320B -> unknown\n");
+				info->flash_id = FLASH_UNKNOWN;
+			} else {
+				debug ("Chip: AMLV320B\n");
+				info->flash_id += FLASH_AMLV320B;
+				info->sector_count = 71;
+				info->size = 0x00800000;
+			}
+			break;				/* =>  8 MB	*/
+		default:
+			debug ("Chip: *** unknown ***\n");
+			info->flash_id = FLASH_UNKNOWN;
+			break;
+		}
+		break;
+
+	default:
+		info->flash_id = FLASH_UNKNOWN;
+		return (0);			/* => no or unknown flash */
+	}
+
+	/* set up sector start address table */
+	switch (value) {
+	case AMD_ID_MIRROR:
+		switch (info->flash_id & FLASH_TYPEMASK) {
+		/* only known types here - no default */
+		case FLASH_AMLV128U:
+		case FLASH_AMLV640U:
+		case FLASH_AMLV320U:
+			for (i = 0; i < info->sector_count; i++) {
+				info->start[i] = base;
+				base += 0x20000;
+			}
+			break;
+		case FLASH_AMLV320B:
+			for (i = 0; i < info->sector_count; i++) {
+				info->start[i] = base;
+				/*
+				 * The first 8 sectors are 8 kB,
+				 * all the other ones  are 64 kB
+				 */
+				base += (i < 8)
+					?  2 * ( 8 << 10)
+					:  2 * (64 << 10);
+			}
+			break;
+		}
+		break;
+
+	default:
+		return (0);
+		break;
+	}
+
+#if 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 */
+		addr = (volatile unsigned long *)(info->start[i]);
+		info->protect[i] = addr[2] & 1;
+	}
+#endif
+
+	/*
+	 * Prevent writes to uninitialized FLASH.
+	 */
+	if (info->flash_id != FLASH_UNKNOWN) {
+		addr = (volatile unsigned long *)info->start[0];
+
+		*addr = 0x00F000F0;	/* reset bank */
+	}
+
+	return (info->size);
+}
+
+
+/*-----------------------------------------------------------------------
+ */
+
+int	flash_erase (flash_info_t *info, int s_first, int s_last)
+{
+	vu_long *addr = (vu_long*)(info->start[0]);
+	int flag, prot, sect, l_sect;
+	ulong start, now, last;
+
+	debug ("flash_erase: first: %d last: %d\n", s_first, s_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 %08lx - aborted\n",
+			info->flash_id);
+		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] = 0x00AA00AA;
+	addr[0x02AA] = 0x00550055;
+	addr[0x0555] = 0x00800080;
+	addr[0x0555] = 0x00AA00AA;
+	addr[0x02AA] = 0x00550055;
+
+	/* Start erase on unprotected sectors */
+	for (sect = s_first; sect<=s_last; sect++) {
+		if (info->protect[sect] == 0) {	/* not protected */
+			addr = (vu_long*)(info->start[sect]);
+			addr[0] = 0x00300030;
+			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 = (vu_long*)(info->start[l_sect]);
+	while ((addr[0] & 0x00800080) != 0x00800080) {
+		if ((now = get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
+			printf ("Timeout\n");
+			return 1;
+		}
+		/* show that we're waiting */
+		if ((now - last) > 100000) {	/* every second */
+			putc ('.');
+			last = now;
+		}
+	}
+
+DONE:
+	/* reset to read mode */
+	addr = (volatile unsigned long *)info->start[0];
+	addr[0] = 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, SWAP(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, SWAP(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, SWAP(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)
+{
+	vu_long *addr = (vu_long*)(info->start[0]);
+	ulong start;
+	ulong rev;
+	int flag;
+	int i;
+
+	/* Check if Flash is (sufficiently) erased */
+	if ((*((vu_long *)dest) & data) != data) {
+		return (2);
+	}
+
+	/* Disable interrupts which might cause a timeout here */
+	flag = disable_interrupts();
+
+	addr[0x0555] = 0x00AA00AA;
+	addr[0x02AA] = 0x00550055;
+	addr[0x0555] = 0x00A000A0;
+
+	*((vu_long *)dest) = data;
+
+	/* re-enable interrupts if necessary */
+	if (flag)
+		enable_interrupts();
+
+	/* data polling for D7 */
+	start = get_timer (0);
+	while ((*((vu_long *)dest) & 0x00800080) != (data & 0x00800080)) {
+		if (get_timer(start) > CFG_FLASH_WRITE_TOUT) {
+			return (1);
+		}
+	}
+	return (0);
+}