/*
 * (C) Copyright 2003
 * Martin Winistoerfer, martinwinistoerfer@gmx.ch.
 *
 * 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
 */

/*
 * File:                flash.c
 *
 * Discription:         This Driver is for 28F320J3A, 28F640J3A and
 *                      28F128J3A Intel flashs working in 16 Bit mode.
 *                      They are single bank flashs.
 *
 *                      Most of this code is taken from existing u-boot
 *                      source code.
 */


#include <common.h>
#include <mpc5xx.h>

#if defined(CONFIG_ENV_IS_IN_FLASH)
# ifndef  CONFIG_ENV_ADDR
#  define CONFIG_ENV_ADDR       (CONFIG_SYS_FLASH_BASE + CONFIG_ENV_OFFSET)
# endif
# ifndef  CONFIG_ENV_SIZE
#  define CONFIG_ENV_SIZE       CONFIG_ENV_SECT_SIZE
# endif
# ifndef  CONFIG_ENV_SECT_SIZE
#  define CONFIG_ENV_SECT_SIZE  CONFIG_ENV_SIZE
# endif
#endif

#define FLASH_ID_MASK                   0xFFFF
#define FLASH_BLOCK_SIZE                0x00010000
#define FLASH_CMD_READ_ID               0x0090
#define FLASH_CMD_RESET                 0x00ff
#define FLASH_CMD_BLOCK_ERASE           0x0020
#define FLASH_CMD_ERASE_CONFIRM         0x00D0
#define FLASH_CMD_CLEAR_STATUS          0x0050
#define FLASH_CMD_SUSPEND_ERASE         0x00B0
#define FLASH_CMD_WRITE                 0x0040
#define FLASH_CMD_PROTECT               0x0060
#define FLASH_CMD_PROTECT_SET           0x0001
#define FLASH_CMD_PROTECT_CLEAR         0x00D0
#define FLASH_STATUS_DONE               0x0080

flash_info_t    flash_info[CONFIG_SYS_MAX_FLASH_BANKS];

/*
 * Local function prototypes
 */
static ulong    flash_get_size          (vu_short *addr, flash_info_t *info);
static int      write_short             (flash_info_t *info, ulong dest, ushort data);
static void     flash_get_offsets       (ulong base, flash_info_t *info);

/*
 * Initialize flash
 */

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;
        }

        /* Static FLASH Bank configuration here - FIXME XXX */
#if 1
        debug ("\n## Get flash bank 1 size @ 0x%08x\n",FLASH_BASE0_PRELIM);
#endif
        size_b0 = flash_get_size((vu_short *)FLASH_BASE0_PRELIM, &flash_info[0]);

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

        flash_get_offsets (FLASH_BASE0_PRELIM, &flash_info[0]);

        flash_info[0].size = size_b0;

#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

#ifdef  CONFIG_ENV_IS_IN_FLASH
        /* ENV protection ON by default */
        flash_protect(FLAG_PROTECT_SET,
                      CONFIG_ENV_ADDR,
                      CONFIG_ENV_ADDR+CONFIG_ENV_SECT_SIZE-1,
                      &flash_info[0]);
#endif

        return size_b0;
}

/*
 * Compute start adress of each sector (block)
 */

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

        if (info->flash_id == FLASH_UNKNOWN) {
                return;
        }

        switch (info->flash_id & FLASH_VENDMASK) {
        case FLASH_MAN_INTEL:
            for (i = 0; i < info->sector_count; i++) {
                info->start[i] = base + i * FLASH_BLOCK_SIZE;
            }
            return;

        default:
            printf ("Don't know sector offsets for flash type 0x%lx\n",
                info->flash_id);
            return;
        }
}

/*
 * Print flash information
 */
void flash_print_info  (flash_info_t *info)
{
        int i;

        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 ("STM ");                break;
        case FLASH_MAN_INTEL:   printf ("Intel ");              break;
        case FLASH_MAN_MT:      printf ("MT ");                 break;
        default:                printf ("Unknown Vendor ");     break;
        }

        switch (info->flash_id & FLASH_TYPEMASK) {
        case FLASH_28F320J3A:   printf ("28F320J3A (32Mbit) 16-Bit\n");
                                break;
        case FLASH_28F640J3A:   printf ("28F640J3A (64Mbit) 16-Bit\n");
                                break;
        case FLASH_28F128J3A:   printf ("28F128J3A (128Mbit) 16-Bit\n");
                                break;
        default:                printf ("Unknown Chip Type\n");
                                break;
        }

        if (info->size >= (1 << 20)) {
                i = 20;
        } else {
                i = 10;
        }
        printf ("  Size: %ld %cB in %d Sectors\n",
                info->size >> i,
                (i == 20) ? 'M' : 'k',
                info->sector_count);

        printf ("  Sector Start Addresses:");
        for (i=0; i<info->sector_count; ++i) {
                if ((i % 5) == 0)
                        printf ("\n   ");
                printf (" %08lX%s",
                        info->start[i],
                        info->protect[i] ? " (RO)" : "     "
                );
        }
        printf ("\n");
        return;
}

/*
 * Get size of flash in bytes.
 * The following code cannot be run from FLASH!
 */

static ulong flash_get_size (vu_short *addr, flash_info_t *info)
{
        vu_short value;

        /* Read Manufacturer ID */
        addr[0] = FLASH_CMD_READ_ID;
        value = addr[0];

        switch (value) {
        case (AMD_MANUFACT & FLASH_ID_MASK):
                info->flash_id = FLASH_MAN_AMD;
                break;
        case (FUJ_MANUFACT & FLASH_ID_MASK):
                info->flash_id = FLASH_MAN_FUJ;
                break;
        case (SST_MANUFACT & FLASH_ID_MASK):
                info->flash_id = FLASH_MAN_SST;
                break;
        case (STM_MANUFACT & FLASH_ID_MASK):
                info->flash_id = FLASH_MAN_STM;
                break;
        case (INTEL_MANUFACT & FLASH_ID_MASK):
                info->flash_id = FLASH_MAN_INTEL;
                break;
        default:
                info->flash_id = FLASH_UNKNOWN;
                info->sector_count = 0;
                info->size = 0;
                addr[0] = FLASH_CMD_RESET;      /* restore read mode */
                return (0);                     /* no or unknown flash  */
        }

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

        switch (value) {
        case (INTEL_ID_28F320J3A  & FLASH_ID_MASK):
                info->flash_id += FLASH_28F320J3A;
                info->sector_count = 32;
                info->size = 0x00400000;
                break;                          /* =>  32 MBit          */

        case (INTEL_ID_28F640J3A & FLASH_ID_MASK):
                info->flash_id += FLASH_28F640J3A;
                info->sector_count = 64;
                info->size = 0x00800000;
                break;                          /* => 64 MBit           */

        case (INTEL_ID_28F128J3A & FLASH_ID_MASK):
                info->flash_id += FLASH_28F128J3A;
                info->sector_count = 128;
                info->size = 0x01000000;
                break;                          /* => 128 MBit          */

        default:
                info->flash_id = FLASH_UNKNOWN;
                addr[0] = FLASH_CMD_RESET;      /* restore read mode */
                return (0);                     /* => no or unknown flash */

        }

        if (info->sector_count > CONFIG_SYS_MAX_FLASH_SECT) {
                printf ("** ERROR: sector count %d > max (%d) **\n",
                        info->sector_count, CONFIG_SYS_MAX_FLASH_SECT);
                info->sector_count = CONFIG_SYS_MAX_FLASH_SECT;
        }

        addr[0] = FLASH_CMD_RESET;              /* restore read mode */

        return (info->size);
}


/*
 * Erase unprotected sectors
 */

int flash_erase (flash_info_t *info, int s_first, int s_last)
{
        int flag, prot, 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_VENDMASK) != FLASH_MAN_INTEL) {
                printf ("Can erase only Intel flash types - 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");
        }

        start = get_timer (0);
        last  = start;

        /* Start erase on unprotected sectors */
        for (sect = s_first; sect<=s_last; sect++) {
                if (info->protect[sect] == 0) { /* not protected */
                        vu_short *addr = (vu_short *)(info->start[sect]);
                        unsigned long status;

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

#ifdef DEBUG
                        printf("Erase sector %d at start addr 0x%08X", sect, (unsigned int)info->start[sect]);
#endif

                        *addr = FLASH_CMD_CLEAR_STATUS;
                        *addr = FLASH_CMD_BLOCK_ERASE;
                        *addr = FLASH_CMD_ERASE_CONFIRM;

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

                        /* wait at least 80us - let's wait 1 ms */
                        udelay (1000);

                        while (((status = *addr) & FLASH_STATUS_DONE) != FLASH_STATUS_DONE) {
                                if ((now=get_timer(start)) > CONFIG_SYS_FLASH_ERASE_TOUT) {
                                        printf("Flash erase timeout at address %lx\n", info->start[sect]);
                                        *addr = FLASH_CMD_SUSPEND_ERASE;
                                        *addr = FLASH_CMD_RESET;
                                        return 1;
                                }

                                /* show that we're waiting */
                                if ((now - last) > 1000) {      /* every second */
                                        putc ('.');
                                        last = now;
                                }
                        }
                        *addr = FLASH_CMD_RESET;
                }
        }
        printf (" done\n");
        return 0;
}

/*
 * Copy memory to flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 * 4 - Flash not identified
 */

int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
        ulong cp, wp;
        ushort data;
        int i, rc;

        if (info->flash_id == FLASH_UNKNOWN) {
                return 4;
        }

        wp = (addr & ~1);       /* get lower word aligned address */

        /*
         * handle unaligned start byte
         */

        if (addr - wp) {
                data = 0;
                data = (data << 8) | *src++;
                --cnt;
                if ((rc = write_short(info, wp, data)) != 0) {
                        return (rc);
                }
                wp += 2;
        }

        /*
         * handle word aligned part
         */

        while (cnt >= 2) {
                data = 0;
                for (i=0; i<2; ++i) {
                        data = (data << 8) | *src++;
                }

                if ((rc = write_short(info, wp, data)) != 0) {
                        return (rc);
                }
                wp  += 2;
                cnt -= 2;
        }

        if (cnt == 0) {
                return (0);
        }

        /*
         * handle unaligned tail bytes
         */

        data = 0;
        for (i=0, cp=wp; i<2 && cnt>0; ++i, ++cp) {
                data = (data << 8) | *src++;
                --cnt;
        }
        for (; i<2; ++i, ++cp) {
                data = (data << 8) | (*(uchar *)cp);
        }

        return (write_short(info, wp, data));

}

/*
 * Write 16 bit (short) to flash
 */

static int write_short (flash_info_t *info, ulong dest, ushort data)
{
        vu_short *addr = (vu_short*)(info->start[0]);
        ulong start;
        int flag;

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

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

        if (!(info->flash_id & FLASH_VENDMASK)) {
                return 4;
        }
        *addr = FLASH_CMD_ERASE_CONFIRM;
        *addr = FLASH_CMD_WRITE;

        *((vu_short *)dest) = data;

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

        /* data polling for D7 */
        start = get_timer (0);

        /* wait for error or finish */
        while(!(addr[0] & FLASH_STATUS_DONE)){
                if (get_timer(start) > CONFIG_SYS_FLASH_WRITE_TOUT) {
                        addr[0] = FLASH_CMD_RESET;
                        return (1);
                }
        }

        *addr = FLASH_CMD_RESET;
        return (0);
}

/*
 * Protects a flash sector
 */

int flash_real_protect(flash_info_t *info, long sector, int prot)
{
        vu_short *addr = (vu_short*)(info->start[sector]);
        ulong start;

        *addr = FLASH_CMD_CLEAR_STATUS;
        *addr = FLASH_CMD_PROTECT;

        if(prot) {
                *addr = FLASH_CMD_PROTECT_SET;
        } else {
                *addr = FLASH_CMD_PROTECT_CLEAR;
        }

        /* wait for error or finish */
        start = get_timer (0);
        while(!(addr[0] & FLASH_STATUS_DONE)){
                if (get_timer(start) > CONFIG_SYS_FLASH_ERASE_TOUT) {
                        printf("Flash protect timeout at address %lx\n",  info->start[sector]);
                        addr[0] = FLASH_CMD_RESET;
                        return (1);
                }
        }
        /* Set software protect flag */
        info->protect[sector] = prot;
        *addr = FLASH_CMD_RESET;
        return (0);
}