/*
 * (C) Copyright 2009
 * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
 *
 * 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 <flash.h>
#include <linux/err.h>

#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <asm/arch/spr_smi.h>

#if !defined(CONFIG_SYS_NO_FLASH)

static struct smi_regs *const smicntl =
    (struct smi_regs * const)CONFIG_SYS_SMI_BASE;
static ulong bank_base[CONFIG_SYS_MAX_FLASH_BANKS] =
    CONFIG_SYS_FLASH_ADDR_BASE;
flash_info_t flash_info[CONFIG_SYS_MAX_FLASH_BANKS];

#define ST_M25Pxx_ID            0x00002020

static struct flash_dev flash_ids[] = {
        {0x10, 0x10000, 2},     /* 64K Byte */
        {0x11, 0x20000, 4},     /* 128K Byte */
        {0x12, 0x40000, 4},     /* 256K Byte */
        {0x13, 0x80000, 8},     /* 512K Byte */
        {0x14, 0x100000, 16},   /* 1M Byte */
        {0x15, 0x200000, 32},   /* 2M Byte */
        {0x16, 0x400000, 64},   /* 4M Byte */
        {0x17, 0x800000, 128},  /* 8M Byte */
        {0x18, 0x1000000, 64},  /* 16M Byte */
        {0x00,}
};

/*
 * smi_wait_xfer_finish - Wait until TFF is set in status register
 * @timeout:     timeout in milliseconds
 *
 * Wait until TFF is set in status register
 */
static void smi_wait_xfer_finish(int timeout)
{
        while (timeout--) {
                if (readl(&smicntl->smi_sr) & TFF)
                        break;
                udelay(1000);
        }
}

/*
 * smi_read_id - Read flash id
 * @info:        flash_info structure pointer
 * @banknum:     bank number
 *
 * Read the flash id present at bank #banknum
 */
static unsigned int smi_read_id(flash_info_t *info, int banknum)
{
        unsigned int value;

        writel(readl(&smicntl->smi_cr1) | SW_MODE, &smicntl->smi_cr1);
        writel(READ_ID, &smicntl->smi_tr);
        writel((banknum << BANKSEL_SHIFT) | SEND | TX_LEN_1 | RX_LEN_3,
               &smicntl->smi_cr2);
        smi_wait_xfer_finish(XFER_FINISH_TOUT);

        value = (readl(&smicntl->smi_rr) & 0x00FFFFFF);

        writel(readl(&smicntl->smi_sr) & ~TFF, &smicntl->smi_sr);
        writel(readl(&smicntl->smi_cr1) & ~SW_MODE, &smicntl->smi_cr1);

        return value;
}

/*
 * flash_get_size - Detect the SMI flash by reading the ID.
 * @base:        Base address of the flash area bank #banknum
 * @banknum:     Bank number
 *
 * Detect the SMI flash by reading the ID. Initializes the flash_info structure
 * with size, sector count etc.
 */
static ulong flash_get_size(ulong base, int banknum)
{
        flash_info_t *info = &flash_info[banknum];
        struct flash_dev *dev;
        unsigned int value;
        unsigned int density;
        int i;

        value = smi_read_id(info, banknum);
        density = (value >> 16) & 0xff;

        for (i = 0, dev = &flash_ids[0]; dev->density != 0x0;
             i++, dev = &flash_ids[i]) {
                if (dev->density == density) {
                        info->size = dev->size;
                        info->sector_count = dev->sector_count;
                        break;
                }
        }

        if (dev->density == 0x0)
                return 0;

        info->flash_id = value & 0xffff;
        info->start[0] = base;

        return info->size;
}

/*
 * smi_read_sr - Read status register of SMI
 * @bank:        bank number
 *
 * This routine will get the status register of the flash chip present at the
 * given bank
 */
static unsigned int smi_read_sr(int bank)
{
        u32 ctrlreg1;

        /* store the CTRL REG1 state */
        ctrlreg1 = readl(&smicntl->smi_cr1);

        /* Program SMI in HW Mode */
        writel(readl(&smicntl->smi_cr1) & ~(SW_MODE | WB_MODE),
               &smicntl->smi_cr1);

        /* Performing a RSR instruction in HW mode */
        writel((bank << BANKSEL_SHIFT) | RD_STATUS_REG, &smicntl->smi_cr2);

        smi_wait_xfer_finish(XFER_FINISH_TOUT);

        /* Restore the CTRL REG1 state */
        writel(ctrlreg1, &smicntl->smi_cr1);

        return readl(&smicntl->smi_sr);
}

/*
 * smi_wait_till_ready - Wait till last operation is over.
 * @bank:        bank number shifted.
 * @timeout:     timeout in milliseconds.
 *
 * This routine checks for WIP(write in progress)bit in Status register(SMSR-b0)
 * The routine checks for #timeout loops, each at interval of 1 milli-second.
 * If successful the routine returns 0.
 */
static int smi_wait_till_ready(int bank, int timeout)
{
        int count;
        unsigned int sr;

        /* One chip guarantees max 5 msec wait here after page writes,
           but potentially three seconds (!) after page erase. */
        for (count = 0; count < timeout; count++) {

                sr = smi_read_sr(bank);
                if (sr < 0)
                        break;
                else if (!(sr & WIP_BIT))
                        return 0;

                /* Try again after 1m-sec */
                udelay(1000);
        }
        printf("SMI controller is still in wait, timeout=%d\n", timeout);
        return -EIO;
}

/*
 * smi_write_enable - Enable the flash to do write operation
 * @bank:        bank number
 *
 * Set write enable latch with Write Enable command.
 * Returns negative if error occurred.
 */
static int smi_write_enable(int bank)
{
        u32 ctrlreg1;
        int timeout = WMODE_TOUT;

        /* Store the CTRL REG1 state */
        ctrlreg1 = readl(&smicntl->smi_cr1);

        /* Program SMI in H/W Mode */
        writel(readl(&smicntl->smi_cr1) & ~SW_MODE, &smicntl->smi_cr1);

        /* Give the Flash, Write Enable command */
        writel((bank << BANKSEL_SHIFT) | WE, &smicntl->smi_cr2);

        smi_wait_xfer_finish(XFER_FINISH_TOUT);

        /* Restore the CTRL REG1 state */
        writel(ctrlreg1, &smicntl->smi_cr1);

        while (timeout--) {
                if (smi_read_sr(bank) & (1 << (bank + WM_SHIFT)))
                        break;
                udelay(1000);
        }

        if (timeout)
                return 0;

        return -1;
}

/*
 * smi_init - SMI initialization routine
 *
 * SMI initialization routine. Sets SMI control register1.
 */
static void smi_init(void)
{
        /* Setting the fast mode values. SMI working at 166/4 = 41.5 MHz */
        writel(HOLD1 | FAST_MODE | BANK_EN | DSEL_TIME | PRESCAL4,
               &smicntl->smi_cr1);
}

/*
 * smi_sector_erase - Erase flash sector
 * @info:        flash_info structure pointer
 * @sector:      sector number
 *
 * Set write enable latch with Write Enable command.
 * Returns negative if error occurred.
 */
static int smi_sector_erase(flash_info_t *info, unsigned int sector)
{
        int bank;
        unsigned int sect_add;
        unsigned int instruction;

        switch (info->start[0]) {
        case SMIBANK0_BASE:
                bank = BANK0;
                break;
        case SMIBANK1_BASE:
                bank = BANK1;
                break;
        case SMIBANK2_BASE:
                bank = BANK2;
                break;
        case SMIBANK3_BASE:
                bank = BANK3;
                break;
        default:
                return -1;
        }

        sect_add = sector * (info->size / info->sector_count);
        instruction = ((sect_add >> 8) & 0x0000FF00) | SECTOR_ERASE;

        writel(readl(&smicntl->smi_sr) & ~(ERF1 | ERF2), &smicntl->smi_sr);

        if (info->flash_id == ST_M25Pxx_ID) {
                /* Wait until finished previous write command. */
                if (smi_wait_till_ready(bank, CONFIG_SYS_FLASH_ERASE_TOUT))
                        return -EBUSY;

                /* Send write enable, before erase commands. */
                if (smi_write_enable(bank))
                        return -EIO;

                /* Put SMI in SW mode */
                writel(readl(&smicntl->smi_cr1) | SW_MODE, &smicntl->smi_cr1);

                /* Send Sector Erase command in SW Mode */
                writel(instruction, &smicntl->smi_tr);
                writel((bank << BANKSEL_SHIFT) | SEND | TX_LEN_4,
                       &smicntl->smi_cr2);
                smi_wait_xfer_finish(XFER_FINISH_TOUT);

                if (smi_wait_till_ready(bank, CONFIG_SYS_FLASH_ERASE_TOUT))
                        return -EBUSY;

                /* Put SMI in HW mode */
                writel(readl(&smicntl->smi_cr1) & ~SW_MODE,
                       &smicntl->smi_cr1);

                return 0;
        } else {
                /* Put SMI in HW mode */
                writel(readl(&smicntl->smi_cr1) & ~SW_MODE,
                       &smicntl->smi_cr1);
                return -EINVAL;
        }
}

/*
 * smi_write - Write to SMI flash
 * @src_addr:    source buffer
 * @dst_addr:    destination buffer
 * @length:      length to write in words
 * @bank:        bank base address
 *
 * Write to SMI flash
 */
static int smi_write(unsigned int *src_addr, unsigned int *dst_addr,
                     unsigned int length, ulong bank_addr)
{
        int banknum;
        unsigned int WM;

        switch (bank_addr) {
        case SMIBANK0_BASE:
                banknum = BANK0;
                WM = WM0;
                break;
        case SMIBANK1_BASE:
                banknum = BANK1;
                WM = WM1;
                break;
        case SMIBANK2_BASE:
                banknum = BANK2;
                WM = WM2;
                break;
        case SMIBANK3_BASE:
                banknum = BANK3;
                WM = WM3;
                break;
        default:
                return -1;
        }

        if (smi_wait_till_ready(banknum, CONFIG_SYS_FLASH_WRITE_TOUT))
                return -EBUSY;

        /* Set SMI in Hardware Mode */
        writel(readl(&smicntl->smi_cr1) & ~SW_MODE, &smicntl->smi_cr1);

        if (smi_write_enable(banknum))
                return -EIO;

        /* Perform the write command */
        while (length--) {
                if (((ulong) (dst_addr) % SFLASH_PAGE_SIZE) == 0) {
                        if (smi_wait_till_ready(banknum,
                                                CONFIG_SYS_FLASH_WRITE_TOUT))
                                return -EBUSY;

                        if (smi_write_enable(banknum))
                                return -EIO;
                }

                *dst_addr++ = *src_addr++;

                if ((readl(&smicntl->smi_sr) & (ERF1 | ERF2)))
                        return -EIO;
        }

        if (smi_wait_till_ready(banknum, CONFIG_SYS_FLASH_WRITE_TOUT))
                return -EBUSY;

        writel(readl(&smicntl->smi_sr) & ~(WCF), &smicntl->smi_sr);

        return 0;
}

/*
 * write_buff - Write to SMI flash
 * @info:        flash info structure
 * @src:         source buffer
 * @dest_addr:   destination buffer
 * @length:      length to write in words
 *
 * Write to SMI flash
 */
int write_buff(flash_info_t *info, uchar *src, ulong dest_addr, ulong length)
{
        return smi_write((unsigned int *)src, (unsigned int *)dest_addr,
                  (length + 3) / 4, info->start[0]);
}

/*
 * flash_init - SMI flash initialization
 *
 * SMI flash initialization
 */
unsigned long flash_init(void)
{
        unsigned long size = 0;
        int i, j;

        smi_init();

        for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
                flash_info[i].flash_id = FLASH_UNKNOWN;
                size += flash_info[i].size = flash_get_size(bank_base[i], i);
        }

        for (j = 0; j < CONFIG_SYS_MAX_FLASH_BANKS; j++) {
                for (i = 1; i < flash_info[j].sector_count; i++)
                        flash_info[j].start[i] =
                            flash_info[j].start[i - 1] +
                            flash_info->size / flash_info->sector_count;

        }

        return size;
}

/*
 * flash_print_info - Print SMI flash information
 *
 * Print SMI flash information
 */
void flash_print_info(flash_info_t *info)
{
        int i;
        if (info->flash_id == FLASH_UNKNOWN) {
                puts("missing or unknown FLASH type\n");
                return;
        }
        printf("  Size: %ld MB in %d Sectors\n",
               info->size >> 20, info->sector_count);

        puts("  Sector Start Addresses:");
        for (i = 0; i < info->sector_count; ++i) {
#ifdef CONFIG_SYS_FLASH_EMPTY_INFO
                int size;
                int erased;
                u32 *flash;

                /*
                 * Check if whole sector is erased
                 */
                size = (info->size) / (info->sector_count);
                flash = (u32 *) info->start[i];
                size = size / sizeof(int);

                while ((size--) && (*flash++ == ~0))
                        ;

                size++;
                if (size)
                        erased = 0;
                else
                        erased = 1;

                if ((i % 5) == 0)
                        printf("\n");

                printf(" %08lX%s%s",
                       info->start[i],
                       erased ? " E" : "  ", info->protect[i] ? "RO " : "   ");
#else
                if ((i % 5) == 0)
                        printf("\n   ");
                printf(" %08lX%s",
                       info->start[i], info->protect[i] ? " (RO)  " : "     ");
#endif
        }
        putc('\n');
        return;
}

/*
 * flash_erase - Erase SMI flash
 *
 * Erase SMI flash
 */
int flash_erase(flash_info_t *info, int s_first, int s_last)
{
        int rcode = 0;
        int prot = 0;
        flash_sect_t sect;

        if (info->flash_id != ST_M25Pxx_ID) {
                puts("Can't erase unknown flash type - aborted\n");
                return 1;
        }

        if ((s_first < 0) || (s_first > s_last)) {
                puts("- no sectors to erase\n");
                return 1;
        }

        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 {
                putc('\n');
        }

        for (sect = s_first; sect <= s_last; sect++) {
                if (info->protect[sect] == 0) {
                        if (smi_sector_erase(info, sect))
                                rcode = 1;
                        else
                                putc('.');
                }
        }
        puts(" done\n");
        return rcode;
}
#endif