/*
 * (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 <common.h>
#include <mpc8xx.h>

flash_info_t    flash_info[CONFIG_SYS_MAX_FLASH_BANKS];

/*
 * 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;
        int i;

        /* Init: no FLASHes known */
        for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; ++i)
                flash_info[i].flash_id = FLASH_UNKNOWN;

        /* Detect size */
        size_b0 = flash_get_size((vu_long *)CONFIG_SYS_FLASH_BASE,
                        &flash_info[0]);

        /* Setup offsets */
        flash_get_offsets(CONFIG_SYS_FLASH_BASE, &flash_info[0]);

#if CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE
        /* Monitor protection ON by default */
        flash_protect(FLAG_PROTECT_SET,
                      CONFIG_SYS_MONITOR_BASE,
                      CONFIG_SYS_MONITOR_BASE+monitor_flash_len-1,
                      &flash_info[0]);
#endif

        flash_info[0].size = size_b0;

        return size_b0;
}

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

        debug("Base address is: %8p\n", caddr);

        caddr[0x0555] = 0xAA;
        caddr[0x02AA] = 0x55;
        caddr[0x0555] = 0x90;

        value = caddr[0];

        debug("Manufact ID: %02x\n", value);

        switch (value) {
        case 0x01:      /*AMD_MANUFACT*/
                info->flash_id = FLASH_MAN_AMD;
                break;

        case 0x04:      /*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            */

        debug("Device ID: %02x\n", value);

        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) {
                now = get_timer(start);
                if (now > CONFIG_SYS_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
         */
        l = addr - wp;

        if (l != 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);

                rc = write_word(info, wp, data);

                if (rc != 0)
                        return rc;

                wp += 4;
        }

        /*
         * handle word aligned part
         */
        while (cnt >= 4) {
                data = 0;
                for (i = 0; i < 4; ++i)
                        data = (data << 8) | *src++;

                rc = write_word(info, wp, data);

                if (rc != 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 *cdest, *cdata;
        volatile unsigned char *addr =
                (volatile unsigned char *)(info->start[0]);
        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) > CONFIG_SYS_FLASH_WRITE_TOUT)
                                return 1;
                }

                cdata++ ;
                cdest++ ;
        }
        return 0;
}