/*
 * (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
 */

/*
 * 09-18-2001, Andreas Heppel: Reduced the code in here to the usage
 *		of AMD's 29F040 and 29F016 flashes, since the BAB750 does use
 *		any other.
 */
 
#include <ppcboot.h>
#include <asm/processor.h>
#include <asm/pci_io.h>

flash_info_t    flash_info[CFG_MAX_FLASH_BANKS]; /* info for FLASH chips    */

/*-----------------------------------------------------------------------
 * Functions
 */
ulong flash_get_size (vu_long *addr, flash_info_t *info);
static int write_word (flash_info_t *info, ulong dest, ulong data);

/*flash command address offsets*/

#define ADDR0           (0x555)
#define ADDR1           (0x2AA)
#define ADDR3           (0x001)

#define FLASH_WORD_SIZE unsigned char

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

unsigned long flash_init (void)
{
    unsigned long size1, size2;
    int i;
    unsigned long base;
    
	
    /* Init: no FLASHes known */
    for (i=0; i<CFG_MAX_FLASH_BANKS; ++i) {
        flash_info[i].flash_id = FLASH_UNKNOWN;
    }

	/* initialise 1st flash */
    size1 = 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",
            size1, size1<<20);
    }

    /* monitor protection ON by default */
    flash_protect(FLAG_PROTECT_SET,
		  base + size1 - CFG_MONITOR_LEN,
		  base + size1 - 1,
		  &flash_info[0]);

	/* initialise 2nd flash */
    size2 = flash_get_size((vu_long *)FLASH_BASE1_PRELIM, &flash_info[1]);

    if (flash_info[0].flash_id == FLASH_UNKNOWN) {
        printf ("## Unknown FLASH on Bank 1 - Size = 0x%08lx = %ld MB\n",
            size2, size2<<20);
    }

    return (size1 + size2);
}

/*-----------------------------------------------------------------------
 */
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");
    	flash_init();
    }
    
    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 AMD_ID_F040B:
    	printf ("AM29F040B (4 Mbit)\n");
        break;
    case AMD_ID_F016D:
    	printf ("AM29F016D (16 Mbit)\n");
        break;
    default:
    	printf ("Unknown Chip Type\n");
        break;
    }

    if (info->size >= (1 << 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);
	}

    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!
 */
ulong flash_get_size (vu_long *addr, flash_info_t *info)
{
	short i;
    ulong vendor, devid;
    ulong base = (ulong)addr;
	volatile unsigned char *caddr = (unsigned char *)addr;
	
#ifdef DEBUG
    printf("flash_get_size for address 0x%lx: \n", (unsigned long)caddr);
#endif

    /* Write auto select command: read Manufacturer ID */
   	caddr[0] = 0xF0;   /* reset bank */
    udelay(10);

	eieio();
    caddr[0x555] = 0xAA;
    udelay(10);
    caddr[0x2AA] = 0x55;
    udelay(10);
    caddr[0x555] = 0x90;
    
    udelay(10);
    
    vendor = caddr[0];
	devid = caddr[1];
	
#ifdef DEBUG
    printf("Manufacturer: 0x%lx\n", vendor);
#endif

    vendor &= 0xff;
    devid &= 0xff;

	/* We accept only two AMD types */
    switch (vendor) {
    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  */
    }

    switch (devid) {
    case (FLASH_WORD_SIZE)AMD_ID_F040B:
        info->flash_id |= AMD_ID_F040B;
        info->sector_count = 8;
        info->size = 0x00080000;
        break;              /* => 0.5 MB      */

    case (FLASH_WORD_SIZE)AMD_ID_F016D:
		info->flash_id |= AMD_ID_F016D;
		info->sector_count = 32;
		info->size         = 0x00200000;
		break;              /* => 2 MB      */
		
    default:
        info->flash_id = FLASH_UNKNOWN;
        return (0);         /* => no or unknown flash */

    }

#ifdef DEBUG
    printf("flash id 0x%lx; sector count 0x%x, size 0x%lx\n", info->flash_id, info->sector_count, info->size);
#endif

    /* check for protected sectors */
    for (i = 0; i < info->sector_count; i++) {
		/* sector base address */
		info->start[i] = base + i * (info->size / info->sector_count);
		/* 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[0] = 0xF0;   /* reset bank */
    }

    return (info->size);
}


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

int flash_erase (flash_info_t *info, int s_first, int s_last)
{
	volatile FLASH_WORD_SIZE *addr = (FLASH_WORD_SIZE *)(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 ERR_NOT_ERASED;
	}

	if ((info->flash_id == FLASH_UNKNOWN) || (info->flash_id > FLASH_AMD_COMP)) {
		printf ("Can't erase unknown flash type - aborted\n");
		return ERR_NOT_ERASED;
	}

	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[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;

	/* Start erase on unprotected sectors */
	for (sect = s_first; sect<=s_last; sect++) {
		if (info->protect[sect] == 0) { /* not protected */
			addr = (FLASH_WORD_SIZE *)(info->start[sect]);
			if (info->flash_id & 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;
				addr[0] = (FLASH_WORD_SIZE)0x00500050;  /* block erase */
				udelay(30000);  /* wait 30 ms */
			}
			else
				addr[0] = (FLASH_WORD_SIZE)0x00300030;  /* sector erase */
			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 = (FLASH_WORD_SIZE *)(info->start[l_sect]);
	while ((addr[0] & (FLASH_WORD_SIZE)0x00800080) != (FLASH_WORD_SIZE)0x00800080) {
		if ((now = get_timer(start)) > CFG_FLASH_ERASE_TOUT) {
			printf ("Timeout\n");
			return ERR_TIMOUT;
		}
		/* show that we're waiting */
		if ((now - last) > 1000) {  /* every second */
			serial_putc ('.');
			last = now;
		}
	}

DONE:
	/* reset to read mode */
	addr = (FLASH_WORD_SIZE *)info->start[0];
	addr[0] = (FLASH_WORD_SIZE)0x00F000F0;  /* reset bank */

	printf (" done\n");
	return ERR_OK;
}

/*-----------------------------------------------------------------------
 * 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);
}

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