/*
 * (C) Copyright 2001
 * Kyle Harris, Nexus Technologies, Inc. kharris@nexus-tech.net
 *
 * (C) Copyright 2001-2004
 * 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 <linux/byteorder/swab.h>


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

/* Board support for 1 or 2 flash devices */
#define FLASH_PORT_WIDTH32
#undef FLASH_PORT_WIDTH16

#ifdef FLASH_PORT_WIDTH16
#define FLASH_PORT_WIDTH        ushort
#define FLASH_PORT_WIDTHV       vu_short
#define SWAP(x)                 (x)
#else
#define FLASH_PORT_WIDTH        ulong
#define FLASH_PORT_WIDTHV       vu_long
#define SWAP(x)                 (x)
#endif

/* Intel-compatible flash ID */
#define INTEL_COMPAT            0x00890089
#define INTEL_ALT               0x00B000B0

/* Intel-compatible flash commands */
#define INTEL_PROGRAM           0x00100010
#define INTEL_ERASE             0x00200020
#define INTEL_CLEAR             0x00500050
#define INTEL_LOCKBIT           0x00600060
#define INTEL_PROTECT           0x00010001
#define INTEL_STATUS            0x00700070
#define INTEL_READID            0x00900090
#define INTEL_CONFIRM           0x00D000D0
#define INTEL_RESET             0xFFFFFFFF

/* Intel-compatible flash status bits */
#define INTEL_FINISHED          0x00800080
#define INTEL_OK                0x00800080

#define FPW     FLASH_PORT_WIDTH
#define FPWV    FLASH_PORT_WIDTHV

#define mb() __asm__ __volatile__ ("" : : : "memory")

/*-----------------------------------------------------------------------
 * Functions
 */
static ulong flash_get_size (FPW *addr, flash_info_t *info);
static int write_data (flash_info_t *info, ulong dest, FPW data);
static void flash_get_offsets (ulong base, flash_info_t *info);
void inline spin_wheel (void);
static void flash_sync_real_protect (flash_info_t * info);
static unsigned char intel_sector_protected (flash_info_t *info, ushort sector);

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

unsigned long flash_init (void)
{
        int i;
        ulong size = 0;
        extern void flash_preinit(void);
        extern void flash_afterinit(ulong, ulong);
        ulong flashbase = CONFIG_SYS_FLASH_BASE;

        flash_preinit();

        for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
                switch (i) {
                case 0:
                        memset(&flash_info[i], 0, sizeof(flash_info_t));
                        flash_get_size ((FPW *) flashbase, &flash_info[i]);
                        flash_get_offsets (flash_info[i].start[0], &flash_info[i]);
                        break;
                default:
                        panic ("configured to many flash banks!\n");
                        break;
                }
                size += flash_info[i].size;

                /* get the h/w and s/w protection status in sync */
                flash_sync_real_protect(&flash_info[i]);
        }

        /* Protect monitor and environment sectors
         */
#if CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE
#ifndef CONFIG_BOOT_ROM
        flash_protect ( FLAG_PROTECT_SET,
                        CONFIG_SYS_MONITOR_BASE,
                        CONFIG_SYS_MONITOR_BASE + monitor_flash_len - 1,
                        &flash_info[0] );
#endif
#endif

#ifdef  CONFIG_ENV_IS_IN_FLASH
        flash_protect ( FLAG_PROTECT_SET,
                        CONFIG_ENV_ADDR,
                        CONFIG_ENV_ADDR + CONFIG_ENV_SIZE - 1, &flash_info[0] );
#endif

        flash_afterinit(flash_info[0].start[0], flash_info[0].size);

        return size;
}

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

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

        if ((info->flash_id & FLASH_VENDMASK) == FLASH_MAN_INTEL) {
                for (i = 0; i < info->sector_count; i++) {
                        info->start[i] = base + (i * PHYS_FLASH_SECT_SIZE);
                }
        }
}

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

        switch (info->flash_id & FLASH_TYPEMASK) {
        case FLASH_28F256J3A:
                printf ("28F256J3A\n");
                break;

        case FLASH_28F128J3A:
                printf ("28F128J3A\n");
                break;

        case FLASH_28F640J3A:
                printf ("28F640J3A\n");
                break;

        case FLASH_28F320J3A:
                printf ("28F320J3A\n");
                break;

        default:
                printf ("Unknown Chip Type\n");
                break;
        }

        printf ("  Size: %ld MB in %d Sectors\n",
                        info->size >> 20, 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;
}

/*
 * The following code cannot be run from FLASH!
 */
static ulong flash_get_size (FPW *addr, flash_info_t *info)
{
        volatile FPW value;

        /* Write auto select command: read Manufacturer ID */
        addr[0x5555] = (FPW) 0x00AA00AA;
        addr[0x2AAA] = (FPW) 0x00550055;
        addr[0x5555] = (FPW) 0x00900090;

        mb ();
        udelay(100);

        value = addr[0];

        switch (value) {

        case (FPW) INTEL_MANUFACT:
                info->flash_id = FLASH_MAN_INTEL;
                break;

        default:
                info->flash_id = FLASH_UNKNOWN;
                info->sector_count = 0;
                info->size = 0;
                addr[0] = (FPW) 0x00FF00FF;     /* restore read mode */
                return (0);                     /* no or unknown flash  */
        }

        mb ();
        value = addr[1];                        /* device ID        */

        switch (value) {

        case (FPW) INTEL_ID_28F256J3A:
                info->flash_id += FLASH_28F256J3A;
                /* In U-Boot we support only 32 MB (no bank-switching) */
                info->sector_count = 256 / 2;
                info->size =  0x04000000 / 2;
                info->start[0] = CONFIG_SYS_FLASH_BASE + 0x02000000;
                break;                          /* => 32 MB     */

        case (FPW) INTEL_ID_28F128J3A:
                info->flash_id += FLASH_28F128J3A;
                info->sector_count = 128;
                info->size = 0x02000000;
                info->start[0] = CONFIG_SYS_FLASH_BASE + 0x02000000;
                break;                          /* => 32 MB     */

        case (FPW) INTEL_ID_28F640J3A:
                info->flash_id += FLASH_28F640J3A;
                info->sector_count = 64;
                info->size = 0x01000000;
                info->start[0] = CONFIG_SYS_FLASH_BASE + 0x03000000;
                break;                          /* => 16 MB     */

        case (FPW) INTEL_ID_28F320J3A:
                info->flash_id += FLASH_28F320J3A;
                info->sector_count = 32;
                info->size = 0x800000;
                info->start[0] = CONFIG_SYS_FLASH_BASE + 0x03800000;
                break;                          /* => 8 MB     */

        default:
                info->flash_id = FLASH_UNKNOWN;
                break;
        }

        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] = (FPW) 0x00FF00FF;             /* restore read mode */

        return (info->size);
}


/*
 * This function gets the u-boot flash sector protection status
 * (flash_info_t.protect[]) in sync with the sector protection
 * status stored in hardware.
 */
static void flash_sync_real_protect (flash_info_t * info)
{
        int i;

        switch (info->flash_id & FLASH_TYPEMASK) {

        case FLASH_28F256J3A:
        case FLASH_28F128J3A:
        case FLASH_28F640J3A:
        case FLASH_28F320J3A:
                for (i = 0; i < info->sector_count; ++i) {
                        info->protect[i] = intel_sector_protected(info, i);
                }
                break;
        default:
                /* no h/w protect support */
                break;
        }
}


/*
 * checks if "sector" in bank "info" is protected. Should work on intel
 * strata flash chips 28FxxxJ3x in 8-bit mode.
 * Returns 1 if sector is protected (or timed-out while trying to read
 * protection status), 0 if it is not.
 */
static unsigned char intel_sector_protected (flash_info_t *info, ushort sector)
{
        FPWV *addr;
        FPWV *lock_conf_addr;
        ulong start;
        unsigned char ret;

        /*
         * first, wait for the WSM to be finished. The rationale for
         * waiting for the WSM to become idle for at most
         * CONFIG_SYS_FLASH_ERASE_TOUT is as follows. The WSM can be busy
         * because of: (1) erase, (2) program or (3) lock bit
         * configuration. So we just wait for the longest timeout of
         * the (1)-(3), i.e. the erase timeout.
         */

        /* wait at least 35ns (W12) before issuing Read Status Register */
        udelay(1);
        addr = (FPWV *) info->start[sector];
        *addr = (FPW) INTEL_STATUS;

        start = get_timer (0);
        while ((*addr & (FPW) INTEL_FINISHED) != (FPW) INTEL_FINISHED) {
                if (get_timer (start) > CONFIG_SYS_FLASH_ERASE_TOUT) {
                        *addr = (FPW) INTEL_RESET; /* restore read mode */
                        printf("WSM busy too long, can't get prot status\n");
                        return 1;
                }
        }

        /* issue the Read Identifier Codes command */
        *addr = (FPW) INTEL_READID;

        /* wait at least 35ns (W12) before reading */
        udelay(1);

        /* Intel example code uses offset of 2 for 16 bit flash */
        lock_conf_addr = (FPWV *) info->start[sector] + 2;
        ret = (*lock_conf_addr & (FPW) INTEL_PROTECT) ? 1 : 0;

        /* put flash back in read mode */
        *addr = (FPW) INTEL_RESET;

        return ret;
}

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

int flash_erase (flash_info_t *info, int s_first, int s_last)
{
        int flag, prot, sect;
        ulong type, start, last;
        int rcode = 0;

        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;
        }

        type = (info->flash_id & FLASH_VENDMASK);
        if ((type != FLASH_MAN_INTEL)) {
                printf ("Can't erase unknown flash type %08lx - aborted\n",
                        info->flash_id);
                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;

        /* 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 */
                        FPWV *addr = (FPWV *) (info->start[sect]);
                        FPW status;

                        printf ("Erasing sector %2d ... ", sect);

                        /* arm simple, non interrupt dependent timer */
                        start = get_timer(0);

                        *addr = (FPW) 0x00500050;       /* clear status register */
                        *addr = (FPW) 0x00200020;       /* erase setup */
                        *addr = (FPW) 0x00D000D0;       /* erase confirm */

                        while (((status = *addr) & (FPW) 0x00800080) != (FPW) 0x00800080) {
                                if (get_timer(start) > CONFIG_SYS_FLASH_ERASE_TOUT) {
                                        printf ("Timeout\n");
                                        *addr = (FPW) 0x00B000B0;       /* suspend erase     */
                                        *addr = (FPW) 0x00FF00FF;       /* reset to read mode */
                                        rcode = 1;
                                        break;
                                }
                        }

                        *addr = 0x00500050;     /* clear status register cmd.   */
                        *addr = 0x00FF00FF;     /* resest to read mode          */

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

/*-----------------------------------------------------------------------
 * 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;
        FPW data;
        int count, i, l, rc, port_width;

        if (info->flash_id == FLASH_UNKNOWN) {
                return 4;
        }
/* get lower word aligned address */
#ifdef FLASH_PORT_WIDTH16
        wp = (addr & ~1);
        port_width = 2;
#else
        wp = (addr & ~3);
        port_width = 4;
#endif

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

                if ((rc = write_data (info, wp, SWAP (data))) != 0) {
                        return (rc);
                }
                wp += port_width;
        }

        /*
         * handle word aligned part
         */
        count = 0;
        while (cnt >= port_width) {
                data = 0;
                for (i = 0; i < port_width; ++i) {
                        data = (data << 8) | *src++;
                }
                if ((rc = write_data (info, wp, SWAP (data))) != 0) {
                        return (rc);
                }
                wp += port_width;
                cnt -= port_width;
                if (count++ > 0x800) {
                        spin_wheel ();
                        count = 0;
                }
        }

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

        /*
         * handle unaligned tail bytes
         */
        data = 0;
        for (i = 0, cp = wp; i < port_width && cnt > 0; ++i, ++cp) {
                data = (data << 8) | *src++;
                --cnt;
        }
        for (; i < port_width; ++i, ++cp) {
                data = (data << 8) | (*(uchar *) cp);
        }

        return (write_data (info, wp, SWAP (data)));
}

/*-----------------------------------------------------------------------
 * Write a word or halfword to Flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */
static int write_data (flash_info_t *info, ulong dest, FPW data)
{
        FPWV *addr = (FPWV *) dest;
        ulong status;
        ulong start;
        int flag;

        /* Check if Flash is (sufficiently) erased */
        if ((*addr & data) != data) {
                printf ("not erased at %08lx (%lx)\n", (ulong) addr, *addr);
                return (2);
        }
        /* Disable interrupts which might cause a timeout here */
        flag = disable_interrupts ();

        *addr = (FPW) 0x00400040;       /* write setup */
        *addr = data;

        /* arm simple, non interrupt dependent timer */
        start = get_timer(0);

        /* wait while polling the status register */
        while (((status = *addr) & (FPW) 0x00800080) != (FPW) 0x00800080) {
                if (get_timer(start) > CONFIG_SYS_FLASH_WRITE_TOUT) {
                        *addr = (FPW) 0x00FF00FF;       /* restore read mode */
                        return (1);
                }
        }

        *addr = (FPW) 0x00FF00FF;       /* restore read mode */

        return (0);
}

void inline spin_wheel (void)
{
        static int p = 0;
        static char w[] = "\\/-";

        printf ("\010%c", w[p]);
        (++p == 3) ? (p = 0) : 0;
}

/*-----------------------------------------------------------------------
 * Set/Clear sector's lock bit, returns:
 * 0 - OK
 * 1 - Error (timeout, voltage problems, etc.)
 */
int flash_real_protect (flash_info_t *info, long sector, int prot)
{
        ulong start;
        int i;
        int rc = 0;
        vu_long *addr = (vu_long *)(info->start[sector]);
        int flag = disable_interrupts();

        *addr = INTEL_CLEAR;    /* Clear status register */
        if (prot) {                     /* Set sector lock bit */
                *addr = INTEL_LOCKBIT;  /* Sector lock bit */
                *addr = INTEL_PROTECT;  /* set */
        }
        else {                          /* Clear sector lock bit */
                *addr = INTEL_LOCKBIT;  /* All sectors lock bits */
                *addr = INTEL_CONFIRM;  /* clear */
        }

        start = get_timer(0);

        while ((*addr & INTEL_FINISHED) != INTEL_FINISHED) {
                if (get_timer(start) > CONFIG_SYS_FLASH_UNLOCK_TOUT) {
                        printf("Flash lock bit operation timed out\n");
                        rc = 1;
                        break;
                }
        }

        if (*addr != INTEL_OK) {
                printf("Flash lock bit operation failed at %08X, CSR=%08X\n",
                       (uint)addr, (uint)*addr);
                rc = 1;
        }

        if (!rc)
                info->protect[sector] = prot;

        /*
         * Clear lock bit command clears all sectors lock bits, so
         * we have to restore lock bits of protected sectors.
         * WARNING: code below re-locks sectors only for one bank (info).
         * This causes problems on boards where several banks share
         * the same chip, as sectors in othere banks will be unlocked
         * but not re-locked. It works fine on pm520 though, as there
         * is only one chip and one bank.
         */
        if (!prot)
        {
                for (i = 0; i < info->sector_count; i++)
                {
                        if (info->protect[i])
                        {
                                start = get_timer(0);
                                addr = (vu_long *)(info->start[i]);
                                *addr = INTEL_LOCKBIT;  /* Sector lock bit */
                                *addr = INTEL_PROTECT;  /* set */
                                while ((*addr & INTEL_FINISHED) != INTEL_FINISHED)
                                {
                                        if (get_timer(start) > CONFIG_SYS_FLASH_UNLOCK_TOUT)
                                        {
                                                printf("Flash lock bit operation timed out\n");
                                                rc = 1;
                                                break;
                                        }
                                }
                        }
                }
                /*
                 * get the s/w sector protection status in sync with the h/w,
                 * in case something went wrong during the re-locking.
                 */
                flash_sync_real_protect(info); /* resets flash to read  mode */
        }

        if (flag)
                enable_interrupts();

        *addr = INTEL_RESET;            /* Reset to read array mode */

        return rc;
}