// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007-2008
 * Stelian Pop <stelian@popies.net>
 * Lead Tech Design <www.leadtechdesign.com>
 *
 * (C) Copyright 2006 ATMEL Rousset, Lacressonniere Nicolas
 *
 * Add Programmable Multibit ECC support for various AT91 SoC
 *     (C) Copyright 2012 ATMEL, Hong Xu
 */

#include <common.h>
#include <log.h>
#include <asm/gpio.h>
#include <asm/arch/gpio.h>
#include <dm/device_compat.h>
#include <dm/devres.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/delay.h>

#include <malloc.h>
#include <nand.h>
#include <watchdog.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/rawnand.h>

#ifdef CONFIG_ATMEL_NAND_HWECC

/* Register access macros */
#define ecc_readl(add, reg)                             \
        readl(add + ATMEL_ECC_##reg)
#define ecc_writel(add, reg, value)                     \
        writel((value), add + ATMEL_ECC_##reg)

#include "atmel_nand_ecc.h"     /* Hardware ECC registers */

#ifdef CONFIG_ATMEL_NAND_HW_PMECC

#ifdef CONFIG_SPL_BUILD
#undef CONFIG_SYS_NAND_ONFI_DETECTION
#endif

struct atmel_nand_host {
        struct pmecc_regs __iomem *pmecc;
        struct pmecc_errloc_regs __iomem *pmerrloc;
        void __iomem            *pmecc_rom_base;

        u8              pmecc_corr_cap;
        u16             pmecc_sector_size;
        u32             pmecc_index_table_offset;
        u32             pmecc_version;

        int             pmecc_bytes_per_sector;
        int             pmecc_sector_number;
        int             pmecc_degree;   /* Degree of remainders */
        int             pmecc_cw_len;   /* Length of codeword */

        /* lookup table for alpha_to and index_of */
        void __iomem    *pmecc_alpha_to;
        void __iomem    *pmecc_index_of;

        /* data for pmecc computation */
        int16_t *pmecc_smu;
        int16_t *pmecc_partial_syn;
        int16_t *pmecc_si;
        int16_t *pmecc_lmu; /* polynomal order */
        int     *pmecc_mu;
        int     *pmecc_dmu;
        int     *pmecc_delta;
};

static struct atmel_nand_host pmecc_host;
static struct nand_ecclayout atmel_pmecc_oobinfo;

/*
 * Return number of ecc bytes per sector according to sector size and
 * correction capability
 *
 * Following table shows what at91 PMECC supported:
 * Correction Capability        Sector_512_bytes        Sector_1024_bytes
 * =====================        ================        =================
 *                2-bits                 4-bytes                  4-bytes
 *                4-bits                 7-bytes                  7-bytes
 *                8-bits                13-bytes                 14-bytes
 *               12-bits                20-bytes                 21-bytes
 *               24-bits                39-bytes                 42-bytes
 *               32-bits                52-bytes                 56-bytes
 */
static int pmecc_get_ecc_bytes(int cap, int sector_size)
{
        int m = 12 + sector_size / 512;
        return (m * cap + 7) / 8;
}

static void pmecc_config_ecc_layout(struct nand_ecclayout *layout,
        int oobsize, int ecc_len)
{
        int i;

        layout->eccbytes = ecc_len;

        /* ECC will occupy the last ecc_len bytes continuously */
        for (i = 0; i < ecc_len; i++)
                layout->eccpos[i] = oobsize - ecc_len + i;

        layout->oobfree[0].offset = 2;
        layout->oobfree[0].length =
                oobsize - ecc_len - layout->oobfree[0].offset;
}

static void __iomem *pmecc_get_alpha_to(struct atmel_nand_host *host)
{
        int table_size;

        table_size = host->pmecc_sector_size == 512 ?
                PMECC_INDEX_TABLE_SIZE_512 : PMECC_INDEX_TABLE_SIZE_1024;

        /* the ALPHA lookup table is right behind the INDEX lookup table. */
        return host->pmecc_rom_base + host->pmecc_index_table_offset +
                        table_size * sizeof(int16_t);
}

static void pmecc_data_free(struct atmel_nand_host *host)
{
        free(host->pmecc_partial_syn);
        free(host->pmecc_si);
        free(host->pmecc_lmu);
        free(host->pmecc_smu);
        free(host->pmecc_mu);
        free(host->pmecc_dmu);
        free(host->pmecc_delta);
}

static int pmecc_data_alloc(struct atmel_nand_host *host)
{
        const int cap = host->pmecc_corr_cap;
        int size;

        size = (2 * cap + 1) * sizeof(int16_t);
        host->pmecc_partial_syn = malloc(size);
        host->pmecc_si = malloc(size);
        host->pmecc_lmu = malloc((cap + 1) * sizeof(int16_t));
        host->pmecc_smu = malloc((cap + 2) * size);

        size = (cap + 1) * sizeof(int);
        host->pmecc_mu = malloc(size);
        host->pmecc_dmu = malloc(size);
        host->pmecc_delta = malloc(size);

        if (host->pmecc_partial_syn &&
                        host->pmecc_si &&
                        host->pmecc_lmu &&
                        host->pmecc_smu &&
                        host->pmecc_mu &&
                        host->pmecc_dmu &&
                        host->pmecc_delta)
                return 0;

        /* error happened */
        pmecc_data_free(host);
        return -ENOMEM;

}

static void pmecc_gen_syndrome(struct mtd_info *mtd, int sector)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
        int i;
        uint32_t value;

        /* Fill odd syndromes */
        for (i = 0; i < host->pmecc_corr_cap; i++) {
                value = pmecc_readl(host->pmecc, rem_port[sector].rem[i / 2]);
                if (i & 1)
                        value >>= 16;
                value &= 0xffff;
                host->pmecc_partial_syn[(2 * i) + 1] = (int16_t)value;
        }
}

static void pmecc_substitute(struct mtd_info *mtd)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
        int16_t __iomem *alpha_to = host->pmecc_alpha_to;
        int16_t __iomem *index_of = host->pmecc_index_of;
        int16_t *partial_syn = host->pmecc_partial_syn;
        const int cap = host->pmecc_corr_cap;
        int16_t *si;
        int i, j;

        /* si[] is a table that holds the current syndrome value,
         * an element of that table belongs to the field
         */
        si = host->pmecc_si;

        memset(&si[1], 0, sizeof(int16_t) * (2 * cap - 1));

        /* Computation 2t syndromes based on S(x) */
        /* Odd syndromes */
        for (i = 1; i < 2 * cap; i += 2) {
                for (j = 0; j < host->pmecc_degree; j++) {
                        if (partial_syn[i] & (0x1 << j))
                                si[i] = readw(alpha_to + i * j) ^ si[i];
                }
        }
        /* Even syndrome = (Odd syndrome) ** 2 */
        for (i = 2, j = 1; j <= cap; i = ++j << 1) {
                if (si[j] == 0) {
                        si[i] = 0;
                } else {
                        int16_t tmp;

                        tmp = readw(index_of + si[j]);
                        tmp = (tmp * 2) % host->pmecc_cw_len;
                        si[i] = readw(alpha_to + tmp);
                }
        }
}

/*
 * This function defines a Berlekamp iterative procedure for
 * finding the value of the error location polynomial.
 * The input is si[], initialize by pmecc_substitute().
 * The output is smu[][].
 *
 * This function is written according to chip datasheet Chapter:
 * Find the Error Location Polynomial Sigma(x) of Section:
 * Programmable Multibit ECC Control (PMECC).
 */
static void pmecc_get_sigma(struct mtd_info *mtd)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);

        int16_t *lmu = host->pmecc_lmu;
        int16_t *si = host->pmecc_si;
        int *mu = host->pmecc_mu;
        int *dmu = host->pmecc_dmu;     /* Discrepancy */
        int *delta = host->pmecc_delta; /* Delta order */
        int cw_len = host->pmecc_cw_len;
        const int16_t cap = host->pmecc_corr_cap;
        const int num = 2 * cap + 1;
        int16_t __iomem *index_of = host->pmecc_index_of;
        int16_t __iomem *alpha_to = host->pmecc_alpha_to;
        int i, j, k;
        uint32_t dmu_0_count, tmp;
        int16_t *smu = host->pmecc_smu;

        /* index of largest delta */
        int ro;
        int largest;
        int diff;

        /* Init the Sigma(x) */
        memset(smu, 0, sizeof(int16_t) * num * (cap + 2));

        dmu_0_count = 0;

        /* First Row */

        /* Mu */
        mu[0] = -1;

        smu[0] = 1;

        /* discrepancy set to 1 */
        dmu[0] = 1;
        /* polynom order set to 0 */
        lmu[0] = 0;
        /* delta[0] = (mu[0] * 2 - lmu[0]) >> 1; */
        delta[0] = -1;

        /* Second Row */

        /* Mu */
        mu[1] = 0;
        /* Sigma(x) set to 1 */
        smu[num] = 1;

        /* discrepancy set to S1 */
        dmu[1] = si[1];

        /* polynom order set to 0 */
        lmu[1] = 0;

        /* delta[1] = (mu[1] * 2 - lmu[1]) >> 1; */
        delta[1] = 0;

        for (i = 1; i <= cap; i++) {
                mu[i + 1] = i << 1;
                /* Begin Computing Sigma (Mu+1) and L(mu) */
                /* check if discrepancy is set to 0 */
                if (dmu[i] == 0) {
                        dmu_0_count++;

                        tmp = ((cap - (lmu[i] >> 1) - 1) / 2);
                        if ((cap - (lmu[i] >> 1) - 1) & 0x1)
                                tmp += 2;
                        else
                                tmp += 1;

                        if (dmu_0_count == tmp) {
                                for (j = 0; j <= (lmu[i] >> 1) + 1; j++)
                                        smu[(cap + 1) * num + j] =
                                                        smu[i * num + j];

                                lmu[cap + 1] = lmu[i];
                                return;
                        }

                        /* copy polynom */
                        for (j = 0; j <= lmu[i] >> 1; j++)
                                smu[(i + 1) * num + j] = smu[i * num + j];

                        /* copy previous polynom order to the next */
                        lmu[i + 1] = lmu[i];
                } else {
                        ro = 0;
                        largest = -1;
                        /* find largest delta with dmu != 0 */
                        for (j = 0; j < i; j++) {
                                if ((dmu[j]) && (delta[j] > largest)) {
                                        largest = delta[j];
                                        ro = j;
                                }
                        }

                        /* compute difference */
                        diff = (mu[i] - mu[ro]);

                        /* Compute degree of the new smu polynomial */
                        if ((lmu[i] >> 1) > ((lmu[ro] >> 1) + diff))
                                lmu[i + 1] = lmu[i];
                        else
                                lmu[i + 1] = ((lmu[ro] >> 1) + diff) * 2;

                        /* Init smu[i+1] with 0 */
                        for (k = 0; k < num; k++)
                                smu[(i + 1) * num + k] = 0;

                        /* Compute smu[i+1] */
                        for (k = 0; k <= lmu[ro] >> 1; k++) {
                                int16_t a, b, c;

                                if (!(smu[ro * num + k] && dmu[i]))
                                        continue;
                                a = readw(index_of + dmu[i]);
                                b = readw(index_of + dmu[ro]);
                                c = readw(index_of + smu[ro * num + k]);
                                tmp = a + (cw_len - b) + c;
                                a = readw(alpha_to + tmp % cw_len);
                                smu[(i + 1) * num + (k + diff)] = a;
                        }

                        for (k = 0; k <= lmu[i] >> 1; k++)
                                smu[(i + 1) * num + k] ^= smu[i * num + k];
                }

                /* End Computing Sigma (Mu+1) and L(mu) */
                /* In either case compute delta */
                delta[i + 1] = (mu[i + 1] * 2 - lmu[i + 1]) >> 1;

                /* Do not compute discrepancy for the last iteration */
                if (i >= cap)
                        continue;

                for (k = 0; k <= (lmu[i + 1] >> 1); k++) {
                        tmp = 2 * (i - 1);
                        if (k == 0) {
                                dmu[i + 1] = si[tmp + 3];
                        } else if (smu[(i + 1) * num + k] && si[tmp + 3 - k]) {
                                int16_t a, b, c;
                                a = readw(index_of +
                                                smu[(i + 1) * num + k]);
                                b = si[2 * (i - 1) + 3 - k];
                                c = readw(index_of + b);
                                tmp = a + c;
                                tmp %= cw_len;
                                dmu[i + 1] = readw(alpha_to + tmp) ^
                                        dmu[i + 1];
                        }
                }
        }
}

static int pmecc_err_location(struct mtd_info *mtd)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
        const int cap = host->pmecc_corr_cap;
        const int num = 2 * cap + 1;
        int sector_size = host->pmecc_sector_size;
        int err_nbr = 0;        /* number of error */
        int roots_nbr;          /* number of roots */
        int i;
        uint32_t val;
        int16_t *smu = host->pmecc_smu;
        int timeout = PMECC_MAX_TIMEOUT_US;

        pmecc_writel(host->pmerrloc, eldis, PMERRLOC_DISABLE);

        for (i = 0; i <= host->pmecc_lmu[cap + 1] >> 1; i++) {
                pmecc_writel(host->pmerrloc, sigma[i],
                             smu[(cap + 1) * num + i]);
                err_nbr++;
        }

        val = PMERRLOC_ELCFG_NUM_ERRORS(err_nbr - 1);
        if (sector_size == 1024)
                val |= PMERRLOC_ELCFG_SECTOR_1024;

        pmecc_writel(host->pmerrloc, elcfg, val);
        pmecc_writel(host->pmerrloc, elen,
                     sector_size * 8 + host->pmecc_degree * cap);

        while (--timeout) {
                if (pmecc_readl(host->pmerrloc, elisr) & PMERRLOC_CALC_DONE)
                        break;
                WATCHDOG_RESET();
                udelay(1);
        }

        if (!timeout) {
                dev_err(mtd->dev,
                        "Timeout to calculate PMECC error location\n");
                return -1;
        }

        roots_nbr = (pmecc_readl(host->pmerrloc, elisr) & PMERRLOC_ERR_NUM_MASK)
                        >> 8;
        /* Number of roots == degree of smu hence <= cap */
        if (roots_nbr == host->pmecc_lmu[cap + 1] >> 1)
                return err_nbr - 1;

        /* Number of roots does not match the degree of smu
         * unable to correct error */
        return -1;
}

static void pmecc_correct_data(struct mtd_info *mtd, uint8_t *buf, uint8_t *ecc,
                int sector_num, int extra_bytes, int err_nbr)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
        int i = 0;
        int byte_pos, bit_pos, sector_size, pos;
        uint32_t tmp;
        uint8_t err_byte;

        sector_size = host->pmecc_sector_size;

        while (err_nbr) {
                tmp = pmecc_readl(host->pmerrloc, el[i]) - 1;
                byte_pos = tmp / 8;
                bit_pos  = tmp % 8;

                if (byte_pos >= (sector_size + extra_bytes))
                        BUG();  /* should never happen */

                if (byte_pos < sector_size) {
                        err_byte = *(buf + byte_pos);
                        *(buf + byte_pos) ^= (1 << bit_pos);

                        pos = sector_num * host->pmecc_sector_size + byte_pos;
                        dev_dbg(mtd->dev,
                                "Bit flip in data area, byte_pos: %d, bit_pos: %d, 0x%02x -> 0x%02x\n",
                                pos, bit_pos, err_byte, *(buf + byte_pos));
                } else {
                        /* Bit flip in OOB area */
                        tmp = sector_num * host->pmecc_bytes_per_sector
                                        + (byte_pos - sector_size);
                        err_byte = ecc[tmp];
                        ecc[tmp] ^= (1 << bit_pos);

                        pos = tmp + nand_chip->ecc.layout->eccpos[0];
                        dev_dbg(mtd->dev,
                                "Bit flip in OOB, oob_byte_pos: %d, bit_pos: %d, 0x%02x -> 0x%02x\n",
                                pos, bit_pos, err_byte, ecc[tmp]);
                }

                i++;
                err_nbr--;
        }

        return;
}

static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
        u8 *ecc)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
        int i, err_nbr;
        u8 *buf_pos, *ecc_pos;

        for (i = 0; i < host->pmecc_sector_number; i++) {
                err_nbr = 0;
                if (pmecc_stat & 0x1) {
                        buf_pos = buf + i * host->pmecc_sector_size;

                        pmecc_gen_syndrome(mtd, i);
                        pmecc_substitute(mtd);
                        pmecc_get_sigma(mtd);

                        err_nbr = pmecc_err_location(mtd);
                        if (err_nbr >= 0) {
                                pmecc_correct_data(mtd, buf_pos, ecc, i,
                                                   host->pmecc_bytes_per_sector,
                                                   err_nbr);
                        } else if (host->pmecc_version < PMECC_VERSION_SAMA5D4) {
                                ecc_pos = ecc + i * host->pmecc_bytes_per_sector;

                                err_nbr = nand_check_erased_ecc_chunk(
                                        buf_pos, host->pmecc_sector_size,
                                        ecc_pos, host->pmecc_bytes_per_sector,
                                        NULL, 0, host->pmecc_corr_cap);
                        }

                        if (err_nbr < 0) {
                                dev_err(mtd->dev, "PMECC: Too many errors\n");
                                mtd->ecc_stats.failed++;
                                return -EBADMSG;
                        }

                        mtd->ecc_stats.corrected += err_nbr;
                }
                pmecc_stat >>= 1;
        }

        return 0;
}

static int atmel_nand_pmecc_read_page(struct mtd_info *mtd,
        struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
{
        struct atmel_nand_host *host = nand_get_controller_data(chip);
        int eccsize = chip->ecc.size;
        uint8_t *oob = chip->oob_poi;
        uint32_t *eccpos = chip->ecc.layout->eccpos;
        uint32_t stat;
        int timeout = PMECC_MAX_TIMEOUT_US;

        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_RST);
        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DISABLE);
        pmecc_writel(host->pmecc, cfg, ((pmecc_readl(host->pmecc, cfg))
                & ~PMECC_CFG_WRITE_OP) | PMECC_CFG_AUTO_ENABLE);

        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_ENABLE);
        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DATA);

        chip->read_buf(mtd, buf, eccsize);
        chip->read_buf(mtd, oob, mtd->oobsize);

        while (--timeout) {
                if (!(pmecc_readl(host->pmecc, sr) & PMECC_SR_BUSY))
                        break;
                WATCHDOG_RESET();
                udelay(1);
        }

        if (!timeout) {
                dev_err(mtd->dev, "Timeout to read PMECC page\n");
                return -1;
        }

        stat = pmecc_readl(host->pmecc, isr);
        if (stat != 0)
                if (pmecc_correction(mtd, stat, buf, &oob[eccpos[0]]) != 0)
                        return -EBADMSG;

        return 0;
}

static int atmel_nand_pmecc_write_page(struct mtd_info *mtd,
                struct nand_chip *chip, const uint8_t *buf,
                int oob_required, int page)
{
        struct atmel_nand_host *host = nand_get_controller_data(chip);
        uint32_t *eccpos = chip->ecc.layout->eccpos;
        int i, j;
        int timeout = PMECC_MAX_TIMEOUT_US;

        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_RST);
        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DISABLE);

        pmecc_writel(host->pmecc, cfg, (pmecc_readl(host->pmecc, cfg) |
                PMECC_CFG_WRITE_OP) & ~PMECC_CFG_AUTO_ENABLE);

        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_ENABLE);
        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DATA);

        chip->write_buf(mtd, (u8 *)buf, mtd->writesize);

        while (--timeout) {
                if (!(pmecc_readl(host->pmecc, sr) & PMECC_SR_BUSY))
                        break;
                WATCHDOG_RESET();
                udelay(1);
        }

        if (!timeout) {
                dev_err(mtd->dev,
                        "Timeout to read PMECC status, fail to write PMECC in oob\n");
                goto out;
        }

        for (i = 0; i < host->pmecc_sector_number; i++) {
                for (j = 0; j < host->pmecc_bytes_per_sector; j++) {
                        int pos;

                        pos = i * host->pmecc_bytes_per_sector + j;
                        chip->oob_poi[eccpos[pos]] =
                                pmecc_readb(host->pmecc, ecc_port[i].ecc[j]);
                }
        }
        chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
out:
        return 0;
}

static void atmel_pmecc_core_init(struct mtd_info *mtd)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        struct atmel_nand_host *host = nand_get_controller_data(nand_chip);
        uint32_t val = 0;
        struct nand_ecclayout *ecc_layout;

        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_RST);
        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_DISABLE);

        switch (host->pmecc_corr_cap) {
        case 2:
                val = PMECC_CFG_BCH_ERR2;
                break;
        case 4:
                val = PMECC_CFG_BCH_ERR4;
                break;
        case 8:
                val = PMECC_CFG_BCH_ERR8;
                break;
        case 12:
                val = PMECC_CFG_BCH_ERR12;
                break;
        case 24:
                val = PMECC_CFG_BCH_ERR24;
                break;
        case 32:
                val = PMECC_CFG_BCH_ERR32;
                break;
        }

        if (host->pmecc_sector_size == 512)
                val |= PMECC_CFG_SECTOR512;
        else if (host->pmecc_sector_size == 1024)
                val |= PMECC_CFG_SECTOR1024;

        switch (host->pmecc_sector_number) {
        case 1:
                val |= PMECC_CFG_PAGE_1SECTOR;
                break;
        case 2:
                val |= PMECC_CFG_PAGE_2SECTORS;
                break;
        case 4:
                val |= PMECC_CFG_PAGE_4SECTORS;
                break;
        case 8:
                val |= PMECC_CFG_PAGE_8SECTORS;
                break;
        }

        val |= (PMECC_CFG_READ_OP | PMECC_CFG_SPARE_DISABLE
                | PMECC_CFG_AUTO_DISABLE);
        pmecc_writel(host->pmecc, cfg, val);

        ecc_layout = nand_chip->ecc.layout;
        pmecc_writel(host->pmecc, sarea, mtd->oobsize - 1);
        pmecc_writel(host->pmecc, saddr, ecc_layout->eccpos[0]);
        pmecc_writel(host->pmecc, eaddr,
                        ecc_layout->eccpos[ecc_layout->eccbytes - 1]);
        /* See datasheet about PMECC Clock Control Register */
        pmecc_writel(host->pmecc, clk, PMECC_CLK_133MHZ);
        pmecc_writel(host->pmecc, idr, 0xff);
        pmecc_writel(host->pmecc, ctrl, PMECC_CTRL_ENABLE);
}

#ifdef CONFIG_SYS_NAND_ONFI_DETECTION
/*
 * pmecc_choose_ecc - Get ecc requirement from ONFI parameters. If
 *                    pmecc_corr_cap or pmecc_sector_size is 0, then set it as
 *                    ONFI ECC parameters.
 * @host: point to an atmel_nand_host structure.
 *        if host->pmecc_corr_cap is 0 then set it as the ONFI ecc_bits.
 *        if host->pmecc_sector_size is 0 then set it as the ONFI sector_size.
 * @chip: point to an nand_chip structure.
 * @cap: store the ONFI ECC correct bits capbility
 * @sector_size: in how many bytes that ONFI require to correct @ecc_bits
 *
 * Return 0 if success. otherwise return the error code.
 */
static int pmecc_choose_ecc(struct atmel_nand_host *host,
                struct nand_chip *chip,
                int *cap, int *sector_size)
{
        /* Get ECC requirement from ONFI parameters */
        *cap = *sector_size = 0;
        if (chip->onfi_version) {
                *cap = chip->ecc_strength_ds;
                *sector_size = chip->ecc_step_ds;
                pr_debug("ONFI params, minimum required ECC: %d bits in %d bytes\n",
                         *cap, *sector_size);
        }

        if (*cap == 0 && *sector_size == 0) {
                /* Non-ONFI compliant */
                dev_info(chip->mtd.dev,
                         "NAND chip is not ONFI compliant, assume ecc_bits is 2 in 512 bytes\n");
                *cap = 2;
                *sector_size = 512;
        }

        /* If head file doesn't specify then use the one in ONFI parameters */
        if (host->pmecc_corr_cap == 0) {
                /* use the most fitable ecc bits (the near bigger one ) */
                if (*cap <= 2)
                        host->pmecc_corr_cap = 2;
                else if (*cap <= 4)
                        host->pmecc_corr_cap = 4;
                else if (*cap <= 8)
                        host->pmecc_corr_cap = 8;
                else if (*cap <= 12)
                        host->pmecc_corr_cap = 12;
                else if (*cap <= 24)
                        host->pmecc_corr_cap = 24;
                else
#ifdef CONFIG_SAMA5D2
                        host->pmecc_corr_cap = 32;
#else
                        host->pmecc_corr_cap = 24;
#endif
        }
        if (host->pmecc_sector_size == 0) {
                /* use the most fitable sector size (the near smaller one ) */
                if (*sector_size >= 1024)
                        host->pmecc_sector_size = 1024;
                else if (*sector_size >= 512)
                        host->pmecc_sector_size = 512;
                else
                        return -EINVAL;
        }
        return 0;
}
#endif

#if defined(NO_GALOIS_TABLE_IN_ROM)
static uint16_t *pmecc_galois_table;
static inline int deg(unsigned int poly)
{
        /* polynomial degree is the most-significant bit index */
        return fls(poly) - 1;
}

static int build_gf_tables(int mm, unsigned int poly,
                           int16_t *index_of, int16_t *alpha_to)
{
        unsigned int i, x = 1;
        const unsigned int k = 1 << deg(poly);
        unsigned int nn = (1 << mm) - 1;

        /* primitive polynomial must be of degree m */
        if (k != (1u << mm))
                return -EINVAL;

        for (i = 0; i < nn; i++) {
                alpha_to[i] = x;
                index_of[x] = i;
                if (i && (x == 1))
                        /* polynomial is not primitive (a^i=1 with 0<i<2^m-1) */
                        return -EINVAL;
                x <<= 1;
                if (x & k)
                        x ^= poly;
        }

        alpha_to[nn] = 1;
        index_of[0] = 0;

        return 0;
}

static uint16_t *create_lookup_table(int sector_size)
{
        int degree = (sector_size == 512) ?
                        PMECC_GF_DIMENSION_13 :
                        PMECC_GF_DIMENSION_14;
        unsigned int poly = (sector_size == 512) ?
                        PMECC_GF_13_PRIMITIVE_POLY :
                        PMECC_GF_14_PRIMITIVE_POLY;
        int table_size = (sector_size == 512) ?
                        PMECC_INDEX_TABLE_SIZE_512 :
                        PMECC_INDEX_TABLE_SIZE_1024;

        int16_t *addr = kzalloc(2 * table_size * sizeof(uint16_t), GFP_KERNEL);
        if (addr && build_gf_tables(degree, poly, addr, addr + table_size))
                return NULL;

        return (uint16_t *)addr;
}
#endif

static int atmel_pmecc_nand_init_params(struct nand_chip *nand,
                struct mtd_info *mtd)
{
        struct atmel_nand_host *host;
        int cap, sector_size;

        host = &pmecc_host;
        nand_set_controller_data(nand, host);

        nand->ecc.mode = NAND_ECC_HW;
        nand->ecc.calculate = NULL;
        nand->ecc.correct = NULL;
        nand->ecc.hwctl = NULL;

#ifdef CONFIG_SYS_NAND_ONFI_DETECTION
        host->pmecc_corr_cap = host->pmecc_sector_size = 0;

#ifdef CONFIG_PMECC_CAP
        host->pmecc_corr_cap = CONFIG_PMECC_CAP;
#endif
#ifdef CONFIG_PMECC_SECTOR_SIZE
        host->pmecc_sector_size = CONFIG_PMECC_SECTOR_SIZE;
#endif
        /* Get ECC requirement of ONFI parameters. And if CONFIG_PMECC_CAP or
         * CONFIG_PMECC_SECTOR_SIZE not defined, then use ecc_bits, sector_size
         * from ONFI.
         */
        if (pmecc_choose_ecc(host, nand, &cap, &sector_size)) {
                dev_err(mtd->dev,
                        "Required ECC %d bits in %d bytes not supported!\n",
                        cap, sector_size);
                return -EINVAL;
        }

        if (cap > host->pmecc_corr_cap)
                dev_info(mtd->dev,
                         "WARNING: Using different ecc correct bits(%d bit) from Nand ONFI ECC reqirement (%d bit).\n",
                         host->pmecc_corr_cap, cap);
        if (sector_size < host->pmecc_sector_size)
                dev_info(mtd->dev,
                         "WARNING: Using different ecc correct sector size (%d bytes) from Nand ONFI ECC reqirement (%d bytes).\n",
                         host->pmecc_sector_size, sector_size);
#else   /* CONFIG_SYS_NAND_ONFI_DETECTION */
        host->pmecc_corr_cap = CONFIG_PMECC_CAP;
        host->pmecc_sector_size = CONFIG_PMECC_SECTOR_SIZE;
#endif

        cap = host->pmecc_corr_cap;
        sector_size = host->pmecc_sector_size;

        /* TODO: need check whether cap & sector_size is validate */
#if defined(NO_GALOIS_TABLE_IN_ROM)
        /*
         * As pmecc_rom_base is the begin of the gallois field table, So the
         * index offset just set as 0.
         */
        host->pmecc_index_table_offset = 0;
#else
        if (host->pmecc_sector_size == 512)
                host->pmecc_index_table_offset = ATMEL_PMECC_INDEX_OFFSET_512;
        else
                host->pmecc_index_table_offset = ATMEL_PMECC_INDEX_OFFSET_1024;
#endif

        pr_debug("Initialize PMECC params, cap: %d, sector: %d\n",
                 cap, sector_size);

        host->pmecc = (struct pmecc_regs __iomem *) ATMEL_BASE_PMECC;
        host->pmerrloc = (struct pmecc_errloc_regs __iomem *)
                        ATMEL_BASE_PMERRLOC;
#if defined(NO_GALOIS_TABLE_IN_ROM)
        pmecc_galois_table = create_lookup_table(host->pmecc_sector_size);
        if (!pmecc_galois_table) {
                dev_err(mtd->dev, "out of memory\n");
                return -ENOMEM;
        }

        host->pmecc_rom_base = (void __iomem *)pmecc_galois_table;
#else
        host->pmecc_rom_base = (void __iomem *) ATMEL_BASE_ROM;
#endif

        /* ECC is calculated for the whole page (1 step) */
        nand->ecc.size = mtd->writesize;

        /* set ECC page size and oob layout */
        switch (mtd->writesize) {
        case 2048:
        case 4096:
        case 8192:
                host->pmecc_degree = (sector_size == 512) ?
                        PMECC_GF_DIMENSION_13 : PMECC_GF_DIMENSION_14;
                host->pmecc_cw_len = (1 << host->pmecc_degree) - 1;
                host->pmecc_sector_number = mtd->writesize / sector_size;
                host->pmecc_bytes_per_sector = pmecc_get_ecc_bytes(
                        cap, sector_size);
                host->pmecc_alpha_to = pmecc_get_alpha_to(host);
                host->pmecc_index_of = host->pmecc_rom_base +
                        host->pmecc_index_table_offset;

                nand->ecc.steps = 1;
                nand->ecc.bytes = host->pmecc_bytes_per_sector *
                                       host->pmecc_sector_number;

                if (nand->ecc.bytes > MTD_MAX_ECCPOS_ENTRIES_LARGE) {
                        dev_err(mtd->dev,
                                "too large eccpos entries. max support ecc.bytes is %d\n",
                                MTD_MAX_ECCPOS_ENTRIES_LARGE);
                        return -EINVAL;
                }

                if (nand->ecc.bytes > mtd->oobsize - PMECC_OOB_RESERVED_BYTES) {
                        dev_err(mtd->dev, "No room for ECC bytes\n");
                        return -EINVAL;
                }
                pmecc_config_ecc_layout(&atmel_pmecc_oobinfo,
                                        mtd->oobsize,
                                        nand->ecc.bytes);
                nand->ecc.layout = &atmel_pmecc_oobinfo;
                break;
        case 512:
        case 1024:
                /* TODO */
                dev_err(mtd->dev,
                        "Unsupported page size for PMECC, use Software ECC\n");
        default:
                /* page size not handled by HW ECC */
                /* switching back to soft ECC */
                nand->ecc.mode = NAND_ECC_SOFT;
                nand->ecc.read_page = NULL;
                nand->ecc.postpad = 0;
                nand->ecc.prepad = 0;
                nand->ecc.bytes = 0;
                return 0;
        }

        /* Allocate data for PMECC computation */
        if (pmecc_data_alloc(host)) {
                dev_err(mtd->dev,
                        "Cannot allocate memory for PMECC computation!\n");
                return -ENOMEM;
        }

        nand->options |= NAND_NO_SUBPAGE_WRITE;
        nand->ecc.read_page = atmel_nand_pmecc_read_page;
        nand->ecc.write_page = atmel_nand_pmecc_write_page;
        nand->ecc.strength = cap;

        /* Check the PMECC ip version */
        host->pmecc_version = pmecc_readl(host->pmerrloc, version);
        dev_dbg(mtd->dev, "PMECC IP version is: %x\n", host->pmecc_version);

        atmel_pmecc_core_init(mtd);

        return 0;
}

#else

/* oob layout for large page size
 * bad block info is on bytes 0 and 1
 * the bytes have to be consecutives to avoid
 * several NAND_CMD_RNDOUT during read
 */
static struct nand_ecclayout atmel_oobinfo_large = {
        .eccbytes = 4,
        .eccpos = {60, 61, 62, 63},
        .oobfree = {
                {2, 58}
        },
};

/* oob layout for small page size
 * bad block info is on bytes 4 and 5
 * the bytes have to be consecutives to avoid
 * several NAND_CMD_RNDOUT during read
 */
static struct nand_ecclayout atmel_oobinfo_small = {
        .eccbytes = 4,
        .eccpos = {0, 1, 2, 3},
        .oobfree = {
                {6, 10}
        },
};

/*

 * Calculate HW ECC
 *
 * function called after a write
 *
 * mtd:        MTD block structure
 * dat:        raw data (unused)
 * ecc_code:   buffer for ECC
 */
static int atmel_nand_calculate(struct mtd_info *mtd,
                const u_char *dat, unsigned char *ecc_code)
{
        unsigned int ecc_value;

        /* get the first 2 ECC bytes */
        ecc_value = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, PR);

        ecc_code[0] = ecc_value & 0xFF;
        ecc_code[1] = (ecc_value >> 8) & 0xFF;

        /* get the last 2 ECC bytes */
        ecc_value = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, NPR) & ATMEL_ECC_NPARITY;

        ecc_code[2] = ecc_value & 0xFF;
        ecc_code[3] = (ecc_value >> 8) & 0xFF;

        return 0;
}

/*
 * HW ECC read page function
 *
 * mtd:        mtd info structure
 * chip:       nand chip info structure
 * buf:        buffer to store read data
 * oob_required:    caller expects OOB data read to chip->oob_poi
 */
static int atmel_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
                                uint8_t *buf, int oob_required, int page)
{
        int eccsize = chip->ecc.size;
        int eccbytes = chip->ecc.bytes;
        uint32_t *eccpos = chip->ecc.layout->eccpos;
        uint8_t *p = buf;
        uint8_t *oob = chip->oob_poi;
        uint8_t *ecc_pos;
        int stat;

        /* read the page */
        chip->read_buf(mtd, p, eccsize);

        /* move to ECC position if needed */
        if (eccpos[0] != 0) {
                /* This only works on large pages
                 * because the ECC controller waits for
                 * NAND_CMD_RNDOUTSTART after the
                 * NAND_CMD_RNDOUT.
                 * anyway, for small pages, the eccpos[0] == 0
                 */
                chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
                                mtd->writesize + eccpos[0], -1);
        }

        /* the ECC controller needs to read the ECC just after the data */
        ecc_pos = oob + eccpos[0];
        chip->read_buf(mtd, ecc_pos, eccbytes);

        /* check if there's an error */
        stat = chip->ecc.correct(mtd, p, oob, NULL);

        if (stat < 0)
                mtd->ecc_stats.failed++;
        else
                mtd->ecc_stats.corrected += stat;

        /* get back to oob start (end of page) */
        chip->cmdfunc(mtd, NAND_CMD_RNDOUT, mtd->writesize, -1);

        /* read the oob */
        chip->read_buf(mtd, oob, mtd->oobsize);

        return 0;
}

/*
 * HW ECC Correction
 *
 * function called after a read
 *
 * mtd:        MTD block structure
 * dat:        raw data read from the chip
 * read_ecc:   ECC from the chip (unused)
 * isnull:     unused
 *
 * Detect and correct a 1 bit error for a page
 */
static int atmel_nand_correct(struct mtd_info *mtd, u_char *dat,
                u_char *read_ecc, u_char *isnull)
{
        struct nand_chip *nand_chip = mtd_to_nand(mtd);
        unsigned int ecc_status;
        unsigned int ecc_word, ecc_bit;

        /* get the status from the Status Register */
        ecc_status = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, SR);

        /* if there's no error */
        if (likely(!(ecc_status & ATMEL_ECC_RECERR)))
                return 0;

        /* get error bit offset (4 bits) */
        ecc_bit = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, PR) & ATMEL_ECC_BITADDR;
        /* get word address (12 bits) */
        ecc_word = ecc_readl(CONFIG_SYS_NAND_ECC_BASE, PR) & ATMEL_ECC_WORDADDR;
        ecc_word >>= 4;

        /* if there are multiple errors */
        if (ecc_status & ATMEL_ECC_MULERR) {
                /* check if it is a freshly erased block
                 * (filled with 0xff) */
                if ((ecc_bit == ATMEL_ECC_BITADDR)
                                && (ecc_word == (ATMEL_ECC_WORDADDR >> 4))) {
                        /* the block has just been erased, return OK */
                        return 0;
                }
                /* it doesn't seems to be a freshly
                 * erased block.
                 * We can't correct so many errors */
                dev_warn(mtd->dev,
                         "multiple errors detected. Unable to correct.\n");
                return -EBADMSG;
        }

        /* if there's a single bit error : we can correct it */
        if (ecc_status & ATMEL_ECC_ECCERR) {
                /* there's nothing much to do here.
                 * the bit error is on the ECC itself.
                 */
                dev_warn(mtd->dev,
                         "one bit error on ECC code. Nothing to correct\n");
                return 0;
        }

        dev_warn(mtd->dev,
                 "one bit error on data. (word offset in the page : 0x%x bit offset : 0x%x)\n",
                 ecc_word, ecc_bit);
        /* correct the error */
        if (nand_chip->options & NAND_BUSWIDTH_16) {
                /* 16 bits words */
                ((unsigned short *) dat)[ecc_word] ^= (1 << ecc_bit);
        } else {
                /* 8 bits words */
                dat[ecc_word] ^= (1 << ecc_bit);
        }
        dev_warn(mtd->dev, "error corrected\n");
        return 1;
}

/*
 * Enable HW ECC : unused on most chips
 */
static void atmel_nand_hwctl(struct mtd_info *mtd, int mode)
{
}

int atmel_hwecc_nand_init_param(struct nand_chip *nand, struct mtd_info *mtd)
{
        nand->ecc.mode = NAND_ECC_HW;
        nand->ecc.calculate = atmel_nand_calculate;
        nand->ecc.correct = atmel_nand_correct;
        nand->ecc.hwctl = atmel_nand_hwctl;
        nand->ecc.read_page = atmel_nand_read_page;
        nand->ecc.bytes = 4;
        nand->ecc.strength = 4;

        if (nand->ecc.mode == NAND_ECC_HW) {
                /* ECC is calculated for the whole page (1 step) */
                nand->ecc.size = mtd->writesize;

                /* set ECC page size and oob layout */
                switch (mtd->writesize) {
                case 512:
                        nand->ecc.layout = &atmel_oobinfo_small;
                        ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
                                        ATMEL_ECC_PAGESIZE_528);
                        break;
                case 1024:
                        nand->ecc.layout = &atmel_oobinfo_large;
                        ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
                                        ATMEL_ECC_PAGESIZE_1056);
                        break;
                case 2048:
                        nand->ecc.layout = &atmel_oobinfo_large;
                        ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
                                        ATMEL_ECC_PAGESIZE_2112);
                        break;
                case 4096:
                        nand->ecc.layout = &atmel_oobinfo_large;
                        ecc_writel(CONFIG_SYS_NAND_ECC_BASE, MR,
                                        ATMEL_ECC_PAGESIZE_4224);
                        break;
                default:
                        /* page size not handled by HW ECC */
                        /* switching back to soft ECC */
                        nand->ecc.mode = NAND_ECC_SOFT;
                        nand->ecc.calculate = NULL;
                        nand->ecc.correct = NULL;
                        nand->ecc.hwctl = NULL;
                        nand->ecc.read_page = NULL;
                        nand->ecc.postpad = 0;
                        nand->ecc.prepad = 0;
                        nand->ecc.bytes = 0;
                        break;
                }
        }

        return 0;
}

#endif /* CONFIG_ATMEL_NAND_HW_PMECC */

#endif /* CONFIG_ATMEL_NAND_HWECC */

static void at91_nand_hwcontrol(struct mtd_info *mtd,
                                         int cmd, unsigned int ctrl)
{
        struct nand_chip *this = mtd_to_nand(mtd);

        if (ctrl & NAND_CTRL_CHANGE) {
                ulong IO_ADDR_W = (ulong) this->IO_ADDR_W;
                IO_ADDR_W &= ~(CONFIG_SYS_NAND_MASK_ALE
                             | CONFIG_SYS_NAND_MASK_CLE);

                if (ctrl & NAND_CLE)
                        IO_ADDR_W |= CONFIG_SYS_NAND_MASK_CLE;
                if (ctrl & NAND_ALE)
                        IO_ADDR_W |= CONFIG_SYS_NAND_MASK_ALE;

#ifdef CONFIG_SYS_NAND_ENABLE_PIN
                at91_set_gpio_value(CONFIG_SYS_NAND_ENABLE_PIN,
                                    !(ctrl & NAND_NCE));
#endif
                this->IO_ADDR_W = (void *) IO_ADDR_W;
        }

        if (cmd != NAND_CMD_NONE)
                writeb(cmd, this->IO_ADDR_W);
}

#ifdef CONFIG_SYS_NAND_READY_PIN
static int at91_nand_ready(struct mtd_info *mtd)
{
        return at91_get_gpio_value(CONFIG_SYS_NAND_READY_PIN);
}
#endif

#ifdef CONFIG_SPL_BUILD
/* The following code is for SPL */
static struct mtd_info *mtd;
static struct nand_chip nand_chip;

static int nand_command(int block, int page, uint32_t offs, u8 cmd)
{
        struct nand_chip *this = mtd_to_nand(mtd);
        int page_addr = page + block * CONFIG_SYS_NAND_PAGE_COUNT;
        void (*hwctrl)(struct mtd_info *mtd, int cmd,
                        unsigned int ctrl) = this->cmd_ctrl;

        while (!this->dev_ready(mtd))
                ;

        if (cmd == NAND_CMD_READOOB) {
                offs += CONFIG_SYS_NAND_PAGE_SIZE;
                cmd = NAND_CMD_READ0;
        }

        hwctrl(mtd, cmd, NAND_CTRL_CLE | NAND_CTRL_CHANGE);

        if ((this->options & NAND_BUSWIDTH_16) && !nand_opcode_8bits(cmd))
                offs >>= 1;

        hwctrl(mtd, offs & 0xff, NAND_CTRL_ALE | NAND_CTRL_CHANGE);
        hwctrl(mtd, (offs >> 8) & 0xff, NAND_CTRL_ALE);
        hwctrl(mtd, (page_addr & 0xff), NAND_CTRL_ALE);
        hwctrl(mtd, ((page_addr >> 8) & 0xff), NAND_CTRL_ALE);
#ifdef CONFIG_SYS_NAND_5_ADDR_CYCLE
        hwctrl(mtd, (page_addr >> 16) & 0x0f, NAND_CTRL_ALE);
#endif
        hwctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);

        hwctrl(mtd, NAND_CMD_READSTART, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
        hwctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);

        while (!this->dev_ready(mtd))
                ;

        return 0;
}

static int nand_is_bad_block(int block)
{
        struct nand_chip *this = mtd_to_nand(mtd);

        nand_command(block, 0, CONFIG_SYS_NAND_BAD_BLOCK_POS, NAND_CMD_READOOB);

        if (this->options & NAND_BUSWIDTH_16) {
                if (readw(this->IO_ADDR_R) != 0xffff)
                        return 1;
        } else {
                if (readb(this->IO_ADDR_R) != 0xff)
                        return 1;
        }

        return 0;
}

#ifdef CONFIG_SPL_NAND_ECC
static int nand_ecc_pos[] = CONFIG_SYS_NAND_ECCPOS;
#define ECCSTEPS (CONFIG_SYS_NAND_PAGE_SIZE / \
                  CONFIG_SYS_NAND_ECCSIZE)
#define ECCTOTAL (ECCSTEPS * CONFIG_SYS_NAND_ECCBYTES)

static int nand_read_page(int block, int page, void *dst)
{
        struct nand_chip *this = mtd_to_nand(mtd);
        u_char ecc_calc[ECCTOTAL];
        u_char ecc_code[ECCTOTAL];
        u_char oob_data[CONFIG_SYS_NAND_OOBSIZE];
        int eccsize = CONFIG_SYS_NAND_ECCSIZE;
        int eccbytes = CONFIG_SYS_NAND_ECCBYTES;
        int eccsteps = ECCSTEPS;
        int i;
        uint8_t *p = dst;
        nand_command(block, page, 0, NAND_CMD_READ0);

        for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
                if (this->ecc.mode != NAND_ECC_SOFT)
                        this->ecc.hwctl(mtd, NAND_ECC_READ);
                this->read_buf(mtd, p, eccsize);
                this->ecc.calculate(mtd, p, &ecc_calc[i]);
        }
        this->read_buf(mtd, oob_data, CONFIG_SYS_NAND_OOBSIZE);

        for (i = 0; i < ECCTOTAL; i++)
                ecc_code[i] = oob_data[nand_ecc_pos[i]];

        eccsteps = ECCSTEPS;
        p = dst;

        for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
                this->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);

        return 0;
}

int spl_nand_erase_one(int block, int page)
{
        struct nand_chip *this = mtd_to_nand(mtd);
        void (*hwctrl)(struct mtd_info *mtd, int cmd,
                        unsigned int ctrl) = this->cmd_ctrl;
        int page_addr;

        if (nand_chip.select_chip)
                nand_chip.select_chip(mtd, 0);

        page_addr = page + block * CONFIG_SYS_NAND_PAGE_COUNT;
        hwctrl(mtd, NAND_CMD_ERASE1, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
        /* Row address */
        hwctrl(mtd, (page_addr & 0xff), NAND_CTRL_ALE | NAND_CTRL_CHANGE);
        hwctrl(mtd, ((page_addr >> 8) & 0xff),
               NAND_CTRL_ALE | NAND_CTRL_CHANGE);
#ifdef CONFIG_SYS_NAND_5_ADDR_CYCLE
        /* One more address cycle for devices > 128MiB */
        hwctrl(mtd, (page_addr >> 16) & 0x0f,
               NAND_CTRL_ALE | NAND_CTRL_CHANGE);
#endif
        hwctrl(mtd, NAND_CMD_ERASE2, NAND_CTRL_CLE | NAND_CTRL_CHANGE);

        while (!this->dev_ready(mtd))
                ;

        nand_deselect();

        return 0;
}
#else
static int nand_read_page(int block, int page, void *dst)
{
        struct nand_chip *this = mtd_to_nand(mtd);

        nand_command(block, page, 0, NAND_CMD_READ0);
        atmel_nand_pmecc_read_page(mtd, this, dst, 0, page);

        return 0;
}
#endif /* CONFIG_SPL_NAND_ECC */

int at91_nand_wait_ready(struct mtd_info *mtd)
{
        struct nand_chip *this = mtd_to_nand(mtd);

        udelay(this->chip_delay);

        return 1;
}

int board_nand_init(struct nand_chip *nand)
{
        int ret = 0;

        nand->ecc.mode = NAND_ECC_SOFT;
#ifdef CONFIG_SYS_NAND_DBW_16
        nand->options = NAND_BUSWIDTH_16;
        nand->read_buf = nand_read_buf16;
#else
        nand->read_buf = nand_read_buf;
#endif
        nand->cmd_ctrl = at91_nand_hwcontrol;
#ifdef CONFIG_SYS_NAND_READY_PIN
        nand->dev_ready = at91_nand_ready;
#else
        nand->dev_ready = at91_nand_wait_ready;
#endif
        nand->chip_delay = 20;
#ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
        nand->bbt_options |= NAND_BBT_USE_FLASH;
#endif

#ifdef CONFIG_ATMEL_NAND_HWECC
#ifdef CONFIG_ATMEL_NAND_HW_PMECC
        ret = atmel_pmecc_nand_init_params(nand, mtd);
#endif
#endif

        return ret;
}

void nand_init(void)
{
        mtd = nand_to_mtd(&nand_chip);
        mtd->writesize = CONFIG_SYS_NAND_PAGE_SIZE;
        mtd->oobsize = CONFIG_SYS_NAND_OOBSIZE;
        nand_chip.IO_ADDR_R = (void __iomem *)CONFIG_SYS_NAND_BASE;
        nand_chip.IO_ADDR_W = (void __iomem *)CONFIG_SYS_NAND_BASE;
        board_nand_init(&nand_chip);

#ifdef CONFIG_SPL_NAND_ECC
        if (nand_chip.ecc.mode == NAND_ECC_SOFT) {
                nand_chip.ecc.calculate = nand_calculate_ecc;
                nand_chip.ecc.correct = nand_correct_data;
        }
#endif

        if (nand_chip.select_chip)
                nand_chip.select_chip(mtd, 0);
}

void nand_deselect(void)
{
        if (nand_chip.select_chip)
                nand_chip.select_chip(mtd, -1);
}

#include "nand_spl_loaders.c"

#else

#ifndef CONFIG_SYS_NAND_BASE_LIST
#define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE }
#endif
static struct nand_chip nand_chip[CONFIG_SYS_MAX_NAND_DEVICE];
static ulong base_addr[CONFIG_SYS_MAX_NAND_DEVICE] = CONFIG_SYS_NAND_BASE_LIST;

int atmel_nand_chip_init(int devnum, ulong base_addr)
{
        int ret;
        struct nand_chip *nand = &nand_chip[devnum];
        struct mtd_info *mtd = nand_to_mtd(nand);

        nand->IO_ADDR_R = nand->IO_ADDR_W = (void  __iomem *)base_addr;

#ifdef CONFIG_NAND_ECC_BCH
        nand->ecc.mode = NAND_ECC_SOFT_BCH;
#else
        nand->ecc.mode = NAND_ECC_SOFT;
#endif
#ifdef CONFIG_SYS_NAND_DBW_16
        nand->options = NAND_BUSWIDTH_16;
#endif
        nand->cmd_ctrl = at91_nand_hwcontrol;
#ifdef CONFIG_SYS_NAND_READY_PIN
        nand->dev_ready = at91_nand_ready;
#endif
        nand->chip_delay = 75;
#ifdef CONFIG_SYS_NAND_USE_FLASH_BBT
        nand->bbt_options |= NAND_BBT_USE_FLASH;
#endif

        ret = nand_scan_ident(mtd, CONFIG_SYS_NAND_MAX_CHIPS, NULL);
        if (ret)
                return ret;

#ifdef CONFIG_ATMEL_NAND_HWECC
#ifdef CONFIG_ATMEL_NAND_HW_PMECC
        ret = atmel_pmecc_nand_init_params(nand, mtd);
#else
        ret = atmel_hwecc_nand_init_param(nand, mtd);
#endif
        if (ret)
                return ret;
#endif

        ret = nand_scan_tail(mtd);
        if (!ret)
                nand_register(devnum, mtd);

        return ret;
}

void board_nand_init(void)
{
        int i;
        for (i = 0; i < CONFIG_SYS_MAX_NAND_DEVICE; i++)
                if (atmel_nand_chip_init(i, base_addr[i]))
                        log_err("atmel_nand: Fail to initialize #%d chip", i);
}
#endif /* CONFIG_SPL_BUILD */