/*
 * (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[CONFIG_SYS_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<CONFIG_SYS_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 (CONFIG_SYS_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+monitor_flash_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)) > CONFIG_SYS_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) > CONFIG_SYS_FLASH_WRITE_TOUT) {
                return (1);
              }
            }
          }

        return (0);
}

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