/*
 * (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 <ppcboot.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+CFG_MONITOR_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:
		case AMD_MANUFACT:
			info->flash_id = FLASH_MAN_AMD;
		break;

		case 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);
}

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