/*
 * (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
 */

/*
 * Modified 4/5/2001
 * Wait for completion of each sector erase command issued
 * 4/5/2001
 * Chris Hallinan - DS4.COM, Inc. - clh@net1plus.com
 */

/*
 * Modified July 20, 2001
 * Strip down to support ONLY the AMD29F032B.
 * Dave Updegraff - Cray, Inc. dave@cray.com
 */

#include <common.h>
#include <ppc4xx.h>
#include <asm/processor.h>

/* The flash chip we use... */
#define AMD_ID_F032B	0x41	/* 29F032B ID  32 Mbit,64 64Kx8 sectors */
#define FLASH_AM320B    0x0009


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, size_b1;
	int i;

	/* Init: no FLASHes known */
	for (i=0; i<CFG_MAX_FLASH_BANKS; ++i) {
		flash_info[i].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 */
	if (CFG_MAX_FLASH_BANKS == 1)
	  {
	    /* Setup offsets */
	    flash_get_offsets (FLASH_BASE0_PRELIM, &flash_info[0]);

#if 0
	    /* Monitor protection ON by default */
	    (void)flash_protect(FLAG_PROTECT_SET,
				FLASH_BASE0_PRELIM,
				FLASH_BASE0_PRELIM+CFG_MONITOR_LEN-1,
				&flash_info[0]);
#endif
	    size_b1 = 0 ;
	    flash_info[0].size = size_b0;
	  }

	return (size_b0 + size_b1);
}


/*-----------------------------------------------------------------------
 */
static void flash_get_offsets (ulong base, flash_info_t *info)
{
	int i;

	/* set up sector start address table */
	for (i = 0; i < info->sector_count; i++)
		info->start[i] = base + (i * 0x00010000);
}

/*-----------------------------------------------------------------------
 */
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;
	default:		printf ("Unknown Vendor ");	break;
	}

	switch (info->flash_id & FLASH_TYPEMASK) {
	case FLASH_AM320B:printf ("AM29F032B (32 Mbit 64x64KB uniform sectors)\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");
}

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


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

/*
 * 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 */
	addr2[ADDR0] = (FLASH_WORD_SIZE)0x00AA00AA;
	addr2[ADDR1] = (FLASH_WORD_SIZE)0x00550055;
	addr2[ADDR0] = (FLASH_WORD_SIZE)0x00900090;

	value = addr2[0];

	switch (value) {
	case (FLASH_WORD_SIZE)AMD_MANUFACT:
		info->flash_id = FLASH_MAN_AMD;
		break;
	default:
		info->flash_id = FLASH_UNKNOWN;
		info->sector_count = 0;
		info->size = 0;
		return (0);			/* no or unknown flash	*/
	}

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

	switch (value) {
	case (FLASH_WORD_SIZE)AMD_ID_F032B:
		info->flash_id += FLASH_AM320B;
		info->sector_count = 64;
		info->size = 0x0400000; /* => 4 MB */
		break;
	default:
		info->flash_id = FLASH_UNKNOWN;
		return (0);			/* => no or unknown flash */

	}

	/* set up sector start address table */
	for (i = 0; i < info->sector_count; i++)
		info->start[i] = base + (i * 0x00010000);

	/* 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]);
        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;

	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 will not be 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);

			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;
			addr2[0] = (FLASH_WORD_SIZE)0x00300030;  /* sector erase */
		    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);

	/* 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 flag;
        int i;

	/* Check if Flash is (sufficiently) erased */
	if ((*((volatile FLASH_WORD_SIZE *)dest) &
             (FLASH_WORD_SIZE)data) != (FLASH_WORD_SIZE)data) {
		return (2);
	}
	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

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

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