/*
 * (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 <ppc4xx.h>
#include <asm/processor.h>

#if CFG_MAX_FLASH_BANKS != 1
#error "CFG_MAX_FLASH_BANKS must be 1"
#endif
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);

#define ADDR0		0x5555
#define ADDR1		0x2aaa
#define FLASH_WORD_SIZE unsigned char

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

unsigned long flash_init (void)
{
	unsigned long size_b0;

	/* Init: no FLASHes known */
	flash_info[0].flash_id = FLASH_UNKNOWN;

	/* Static FLASH Bank configuration here - FIXME XXX */

	size_b0 = flash_get_size ((vu_long *) FLASH_BASE0_PRELIM,
				  &flash_info[0]);

	if (flash_info[0].flash_id == FLASH_UNKNOWN) {
		printf ("## Unknown FLASH on Bank 0- Size=0x%08lx=%ld MB\n",
			size_b0, size_b0 << 20);
	}

	/* Only one bank */
	/* Setup offsets */
	flash_get_offsets (FLASH_BASE0_PRELIM, &flash_info[0]);

	/* Monitor protection ON by default */
	(void) flash_protect (FLAG_PROTECT_SET,
			      FLASH_BASE0_PRELIM,
			      FLASH_BASE0_PRELIM + monitor_flash_len - 1,
			      &flash_info[0]);
	flash_info[0].size = size_b0;

	return size_b0;
}


/*-----------------------------------------------------------------------*/
/*
 * This implementation assumes that the flash chips are uniform sector
 * devices. This is true for all likely flash devices on a HCUx.
 */
static void flash_get_offsets (ulong base, flash_info_t * info)
{
	unsigned idx;
	unsigned long sector_size = info->size / info->sector_count;

	for (idx = 0; idx < info->sector_count; idx += 1) {
		info->start[idx] = base + (idx * sector_size);
	}
}

/*-----------------------------------------------------------------------*/
void flash_print_info (flash_info_t * info)
{
	int i;
	int k;
	int size;
	int erased;
	volatile unsigned long *flash;

	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;
	case FLASH_MAN_SST:
		printf ("SST ");
		break;
	case FLASH_MAN_STM:
		printf ("ST Micro ");
		break;
	default:
		printf ("Unknown Vendor ");
		break;
	}

	  /* (Reduced table of only parts expected in HCUx boards.) */
	switch (info->flash_id) {
	case FLASH_MAN_AMD | FLASH_AM040:
		printf ("AM29F040 (512 Kbit, uniform sector size)\n");
		break;
	case FLASH_MAN_STM | FLASH_AM040:
		printf ("MM29W040W (512 Kbit, uniform sector size)\n");
		break;
	default:
		printf ("Unknown Chip Type\n");
		break;
	}

	printf ("  Size: %ld KB in %d Sectors\n",
		info->size >> 10, info->sector_count);

	printf ("  Sector Start Addresses:");
	for (i = 0; i < info->sector_count; ++i) {
		/*
		 * Check if whole sector is erased
		 */
		if (i != (info->sector_count - 1))
			size = info->start[i + 1] - info->start[i];
		else
			size = info->start[0] + info->size - info->start[i];
		erased = 1;
		flash = (volatile unsigned long *) info->start[i];
		size = size >> 2;	/* divide by 4 for longword access */
		for (k = 0; k < size; k++) {
			if (*flash++ != 0xffffffff) {
				erased = 0;
				break;
			}
		}

		if ((i % 5) == 0)
			printf ("\n   ");
		printf (" %08lX%s%s",
			info->start[i],
			erased ? " E" : "  ", 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;
	FLASH_WORD_SIZE value;
	ulong base = (ulong) addr;
	volatile FLASH_WORD_SIZE *addr2 = (FLASH_WORD_SIZE *) addr;

	/* Write auto select command: read Manufacturer ID */
	asm("isync");
	addr2[ADDR0] = (FLASH_WORD_SIZE) 0x00AA00AA;
	asm("isync");
	addr2[ADDR1] = (FLASH_WORD_SIZE) 0x00550055;
	asm("isync");
	addr2[ADDR0] = (FLASH_WORD_SIZE) 0x00900090;
	asm("isync");

	value = addr2[0];
	asm("isync");

	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;
	case (FLASH_WORD_SIZE)STM_MANUFACT:
		info->flash_id = FLASH_MAN_STM;
		break;
	default:
		info->flash_id = FLASH_UNKNOWN;
		info->sector_count = 0;
		info->size = 0;
		printf("Unknown flash manufacturer code: 0x%x at %p\n",
		       value, addr);
		addr2[ADDR0] = (FLASH_WORD_SIZE) 0;
		return (0);	/* no or unknown flash  */
	}

	value = addr2[1];	/* device ID		*/

	switch (value) {
	case (FLASH_WORD_SIZE) AMD_ID_F040B:
		info->flash_id += FLASH_AM040;
		info->sector_count = 8;
		info->size = 0x0080000;	/* => 512 ko */
		break;
	case (FLASH_WORD_SIZE) AMD_ID_LV040B:
		info->flash_id += FLASH_AM040;
		info->sector_count = 8;
		info->size = 0x0080000;	/* => 512 ko */
		break;
	case (FLASH_WORD_SIZE)STM_ID_M29W040B: /* most likele HCU5 chip */
		info->flash_id += FLASH_AM040;
		info->sector_count = 8;
		info->size = 0x0080000; /* => 512 ko */
		break;
	default:
		info->flash_id = FLASH_UNKNOWN;
		return (0);	/* => no or unknown flash */

	}

	  /* Calculate the sector offsets (Use HCUx Optimized code). */
	flash_get_offsets(base, info);

	/* 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_VENDMASK) == 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);
}

int wait_for_DQ7 (flash_info_t * info, int sect)
{
	ulong start, now, last;
	volatile FLASH_WORD_SIZE *addr =
		(FLASH_WORD_SIZE *) (info->start[sect]);

	start = get_timer (0);
	last = start;
	while ((addr[0] & (FLASH_WORD_SIZE) 0x00800080) !=
	       (FLASH_WORD_SIZE) 0x00800080) {
		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;
		}
	}
	return 0;
}

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

int flash_erase (flash_info_t * info, int s_first, int s_last)
{
	volatile FLASH_WORD_SIZE *addr = (FLASH_WORD_SIZE *) (info->start[0]);
	volatile FLASH_WORD_SIZE *addr2;
	int flag, prot, sect, l_sect;
	int i;

	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) {
		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 not erased!\n",
			prot);
	} else {
		printf ("\n");
	}

	l_sect = -1;

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

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect <= s_last; sect++) {
		if (info->protect[sect] == 0) {	/* not protected */
			addr2 = (FLASH_WORD_SIZE *) (info->start[sect]);
			printf ("Erasing sector %p\n", addr2);	/* CLH */

			if ((info->flash_id & FLASH_VENDMASK) ==
			    FLASH_MAN_SST) {
				addr[ADDR0] = (FLASH_WORD_SIZE) 0x00AA00AA;
				addr[ADDR1] = (FLASH_WORD_SIZE) 0x00550055;
				addr[ADDR0] = (FLASH_WORD_SIZE) 0x00800080;
				addr[ADDR0] = (FLASH_WORD_SIZE) 0x00AA00AA;
				addr[ADDR1] = (FLASH_WORD_SIZE) 0x00550055;
				/* block erase */
				addr2[0] = (FLASH_WORD_SIZE) 0x00500050;
				for (i = 0; i < 50; i++) udelay (1000);
			} else {
				addr[ADDR0] = (FLASH_WORD_SIZE) 0x00AA00AA;
				addr[ADDR1] = (FLASH_WORD_SIZE) 0x00550055;
				addr[ADDR0] = (FLASH_WORD_SIZE) 0x00800080;
				addr[ADDR0] = (FLASH_WORD_SIZE) 0x00AA00AA;
				addr[ADDR1] = (FLASH_WORD_SIZE) 0x00550055;
				/* sector erase */
				addr2[0] = (FLASH_WORD_SIZE) 0x00300030;
			}
			l_sect = sect;
			/*
			 * Wait for each sector to complete, it's more
			 * reliable.  According to AMD Spec, you must
			 * issue all erase commands within a specified
			 * timeout.  This has been seen to fail, especially
			 * if printf()s are included (for debug)!!
			 */
			wait_for_DQ7 (info, 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;
	wait_for_DQ7 (info, l_sect);

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 = (FLASH_WORD_SIZE *) dest;
	volatile FLASH_WORD_SIZE *data2 = (FLASH_WORD_SIZE *) & data;
	ulong start;
	int i;

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

	for (i = 0; i < 4 / sizeof (FLASH_WORD_SIZE); i++) {
		int flag;

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

		addr2[ADDR0] = (FLASH_WORD_SIZE) 0x00AA00AA;
		addr2[ADDR1] = (FLASH_WORD_SIZE) 0x00550055;
		addr2[ADDR0] = (FLASH_WORD_SIZE) 0x00A000A0;

		dest2[i] = data2[i];

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

		/* data polling for D7 */
		start = get_timer (0);
		while ((dest2[i] & (FLASH_WORD_SIZE) 0x00800080) !=
		       (data2[i] & (FLASH_WORD_SIZE) 0x00800080)) {

			if (get_timer (start) > CFG_FLASH_WRITE_TOUT) {
				return (1);
			}
		}
	}

	return (0);
}