/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support
 * ----------------------------------------------------------------------------
 * Copyright (c) 2010, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
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/**
 * \file
 *
 * EccNandFlash layer is called by SkipBlockNandFlash driver, it will call the bl driver (RawNandFlash)
 * to do write/read operations, and do ECC check to the write/read result, it then will feedback the
 * ecc check result to the upper SkipBlockNandFlash layer driver.
 *
 * -# EccNandFlash_Initialize is used to initializes an EccNandFlash instance.
 * -# EccNandFlash_WritePage is used to write a Nandflash page with ecc result, the function
 *      will calculate ecc for the data that is going to be written, and write data and spare(with
 *      calculated ecc) to Nandflash device.
 * -# EccNandFlash_ReadPage is uese to read a Nandflash page with ecc check, the function
 *      will read out data and spare first, then it calculates ecc with data and then compare with
 *      the readout ecc, and feedback the ecc check result to dl driver.
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include <stdint.h>
#include "memories.h"

#include <string.h>
#include <assert.h>

/*----------------------------------------------------------------------------
 *        Internal definitions
 *----------------------------------------------------------------------------*/

/** Casts */
#define MODEL(ecc)  ((struct NandFlashModel *) ecc)
#define RAW(ecc)    ((struct RawNandFlash *) ecc)

/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/
/**
 * \brief  Initializes an EccNandFlash instance.
 *
 * \param ecc  Pointer to an EccNandFlash instance.
 * \param model  Pointer to the underlying nand chip model. Can be 0.
 * \param commandAddress  Address at which commands are sent.
 * \param addressAddress  Address at which addresses are sent.
 * \param dataAddress  Address at which data is sent.
 * \param pinChipEnable  Pin controlling the CE signal of the NandFlash.
 * \param pinReadyBusy  Pin used to monitor the ready/busy signal of the Nand.
 * \return 0 if the initialization is done; or returns a error code.
 */
unsigned char EccNandFlash_Initialize(
    struct EccNandFlash *ecc,
    const struct NandFlashModel *model,
    unsigned int commandAddress,
    unsigned int addressAddress,
    unsigned int dataAddress,
    const Pin pinChipEnable,
    const Pin pinReadyBusy)
{
    unsigned char rc;
    rc = RawNandFlash_Initialize(RAW(ecc),
                                 model,
                                 commandAddress,
                                 addressAddress,
                                 dataAddress,
                                 pinChipEnable,
                                 pinReadyBusy);
#if defined(HARDWARE_ECC)
    {
        unsigned int ecc_page;
        switch(NandFlashModel_GetPageDataSize(MODEL(ecc))) {
            case  512: ecc_page = SMC_CFG_PAGESIZE_PS512_16;  break;
            case 1024: ecc_page = SMC_CFG_PAGESIZE_PS1024_32; break;
            case 2048: ecc_page = SMC_CFG_PAGESIZE_PS2048_64; break;
            case 4096: ecc_page = SMC_CFG_PAGESIZE_PS4096_128; break;
            default:
                TRACE_ERROR("PageSize %d not compatible with ECC\n\r",
                            NandFlashModel_GetPageDataSize(MODEL(ecc)));
                return NandCommon_ERROR_ECC_NOT_COMPATIBLE;
        }
        SMC_ECC_Configure(SMC, SMC_ECC_MD_TYPCORREC_C256B,
                           ecc_page);
    }
#endif
    return rc;
}

/**
 * \brief  Reads the data and/or spare of a page of a nandflash chip, and verify that
 * the data is valid using the ECC information contained in the spare. If one
 * buffer pointer is 0, the corresponding area is not saved.
 * \param ecc  Pointer to an EccNandFlash instance.
 * \param block  Number of block to read from.
 * \param page  Number of page to read inside given block.
 * \param data  Data area buffer.
 * \param spare  Spare area buffer.
 * \return 0 if the data has been read and is valid; otherwise returns either
 * NandCommon_ERROR_CORRUPTEDDATA or ...
 */
unsigned char EccNandFlash_ReadPage(
    const struct EccNandFlash *ecc,
    unsigned short block,
    unsigned short page,
    void *data,
    void *spare)
{
    unsigned char tmpSpare[NandCommon_MAXPAGESPARESIZE];
    unsigned char error;
#ifndef HARDWARE_ECC
    unsigned char tmpData[NandCommon_MAXPAGEDATASIZE];
    unsigned char hamming[NandCommon_MAXSPAREECCBYTES];
#else
    unsigned char hsiaoInSpare[NandCommon_MAXSPAREECCBYTES];
    unsigned char hsiao[NandCommon_MAXSPAREECCBYTES];
#endif

    unsigned short pageDataSize = NandFlashModel_GetPageDataSize(MODEL(ecc));
    unsigned char pageSpareSize = NandFlashModel_GetPageSpareSize(MODEL(ecc));

    TRACE_DEBUG("EccNandFlash_ReadPage(B#%d:P#%d)\n\r", block, page);
#ifndef HARDWARE_ECC
    /* Start by reading the spare and the data */
    error = RawNandFlash_ReadPage(RAW(ecc), block, page, tmpData, tmpSpare);
    if (error) {

        TRACE_ERROR("EccNandFlash_ReadPage: Failed to read page\n\r");
        return error;
    }

    /* Retrieve ECC information from page and verify the data */
    NandSpareScheme_ReadEcc(NandFlashModel_GetScheme(MODEL(ecc)), tmpSpare, hamming);
    error = Hamming_Verify256x(tmpData, pageDataSize, hamming);
#else
    /* Start by reading the spare area */
    /* Note: Can't read data and spare at the same time, otherwise, the ECC parity generation will be incorrect. */
    error = RawNandFlash_ReadPage(RAW(ecc), block, page, 0, tmpSpare);
    if (error) {

        TRACE_ERROR("EccNandFlash_ReadPage: $page %d.%d\n\r",
                    block, page);
        return error;
    }
    /* Retrieve ECC information from page and verify the data */
    NandSpareScheme_ReadEcc(NandFlashModel_GetScheme(MODEL(ecc)), tmpSpare, hsiaoInSpare);

    /* Reading the main data area */
    error = RawNandFlash_ReadPage(RAW(ecc), block, page, (unsigned char*)data, 0);
    if (error) {

        TRACE_ERROR("EccNandFlash_ReadPage: $page %d.%d\n\r",
                    block, page);
        return error;
    }
    SMC_ECC_GetEccParity(pageDataSize, hsiao, NandFlashModel_GetDataBusWidth(MODEL(ecc)));
    /* Verify the data */
    error = SMC_ECC_VerifyHsiao((unsigned char*) data,
                              pageDataSize,
                              hsiaoInSpare,
                              hsiao,
                              NandFlashModel_GetDataBusWidth(MODEL(ecc)));
#endif
    if (error && (error != Hamming_ERROR_SINGLEBIT)) {

        TRACE_ERROR("EccNandFlash_ReadPage: at B%d.P%d Unrecoverable data\n\r",
                    block, page);
        return NandCommon_ERROR_CORRUPTEDDATA;
    }
#ifndef HARDWARE_ECC
    /* Copy data and/or spare into final buffers */
    if (data) {

        memcpy(data, tmpData, pageDataSize);
    }
    if (spare) {

        memcpy(spare, tmpSpare, pageSpareSize);
    }
#else
     if (spare) {

        memcpy(spare, tmpSpare, pageSpareSize);
    }
#endif
    return 0;
}

/**
 * \brief  Writes the data and/or spare area of a nandflash page, after calculating an
 * ECC for the data area and storing it in the spare. If no data buffer is
 * provided, the ECC is read from the existing page spare. If no spare buffer
 * is provided, the spare area is still written with the ECC information
 * calculated on the data buffer.
 * \param ecc  Pointer to an EccNandFlash instance.
 * \param block  Number of block to read from.
 * \param page  Number of page to read inside given block.
 * \param data  Data area buffer.
 * \param spare  Spare area buffer.
 * \return 0 if successful; otherwise returns an error code.
 */
unsigned char EccNandFlash_WritePage(
    const struct EccNandFlash *ecc,
    unsigned short block,
    unsigned short page,
    void *data,
    void *spare)
{
    unsigned char error;
    unsigned char tmpSpare[NandCommon_MAXPAGESPARESIZE];
    unsigned short pageDataSize = NandFlashModel_GetPageDataSize(MODEL(ecc));
    unsigned short pageSpareSize = NandFlashModel_GetPageSpareSize(MODEL(ecc));
#ifndef HARDWARE_ECC
    unsigned char hamming[NandCommon_MAXSPAREECCBYTES];
#else
    unsigned char hsiao[NandCommon_MAXSPAREECCBYTES];
#endif

    assert( (data != NULL) || (spare != NULL) ) ;
//    TRACE_DEBUG(  "EccNandFlash_WritePage: At least one area must be written\n\r" ) ;
    TRACE_DEBUG("EccNandFlash_WritePage(B#%d:P#%d)\n\r", block, page);
#ifndef HARDWARE_ECC
    /* Compute ECC on the new data, if provided */
    /* If not provided, hamming code set to 0xFFFF.. to keep existing bytes */
    memset(hamming, 0xFF, NandCommon_MAXSPAREECCBYTES);
    if (data) {

        /* Compute hamming code on data */
        Hamming_Compute256x(data, pageDataSize, hamming);
    }

    /* Store code in spare buffer (if no buffer provided, use a temp. one) */
    if (!spare) {

        spare = tmpSpare;
        memset(spare, 0xFF, pageSpareSize);
    }
    NandSpareScheme_WriteEcc(NandFlashModel_GetScheme(MODEL(ecc)), spare, hamming);

    /* Perform write operation */
    error = RawNandFlash_WritePage(RAW(ecc), block, page, data, spare);
    if (error) {

        TRACE_ERROR("EccNandFlash_WritePage: Failed to write page\n\r");
        return error;
    }

#else
    /* Store code in spare buffer (if no buffer provided, use a temp. one) */
    if (!spare) {
        spare = tmpSpare;
        memset(spare, 0xFF, pageSpareSize);
    }
    /* Perform write operation */
    error = RawNandFlash_WritePage(RAW(ecc), block, page, data, spare);
    if (error) {

        TRACE_ERROR("EccNandFlash_WritePage: Failed to write page\n\r");
        return error;
    }
    SMC_ECC_GetEccParity(pageDataSize, hsiao, NandFlashModel_GetDataBusWidth(MODEL(ecc)));
    /* Perform write operation */
    NandSpareScheme_WriteEcc(NandFlashModel_GetScheme(MODEL(ecc)), spare, hsiao);
    error = RawNandFlash_WritePage(RAW(ecc), block, page, 0, spare);
    if (error) {
        TRACE_ERROR("EccNandFlash_WritePage: Failed to write page\n\r");
        return error;
    }
#endif
    return 0;
}