size = nr_sets * sizeof(*info->mtds); 
/*分配mtd_info结构体*/ 
info->mtds = kmalloc(size, GFP_KERNEL); 
if (info->mtds == NULL) 
{ 
    dev_err(&pdev->dev, "failed to allocate mtd storage\n"); 
    err = -ENOMEM; 
    goto exit_error; 
} 
 
memset(info->mtds, 0, size); 
 
/* initialise all possible chips */ 
 
nmtd = info->mtds; 
 
for (setno = 0; setno < nr_sets; setno++, nmtd++) 
{ 
    pr_debug("initialising set %d (%p, info %p)\n", setno, nmtd, info); 
    /*准备使用内核中的nand mtd框架，首先初始化一些底层的操作*/ 
    s3c2410_nand_init_chip(info, nmtd, sets); 
    /*读写chip id 并初始化一些mtd_info的域*/ 
    nmtd->scan_res = nand_scan_ident(&nmtd->mtd, 
                                     (sets) ? sets->nr_chips : 1); 
 
    if (nmtd->scan_res == 0) 
    { 
        s3c2410_nand_update_chip(info, nmtd); 
        /*将mtd_info中的函数指针初始化*/ 
        nand_scan_tail(&nmtd->mtd); 
        s3c2410_nand_add_partition(info, nmtd, sets); 
    } 
 
    if (sets != NULL) 
        sets++; 
}

/* s3c2410_nand_init_chip 
 * 
 * init a single instance of an chip 
*/ 
static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info, 
                                   struct s3c2410_nand_mtd *nmtd, 
                                   struct s3c2410_nand_set *set) 
{ 
    struct nand_chip *chip = &nmtd->chip; 
    void __iomem *regs = info->regs; 
    /*初始化必须实现的几个函数*/ 
    chip->write_buf    = s3c2410_nand_write_buf; 
    chip->read_buf     = s3c2410_nand_read_buf; 
    chip->select_chip  = s3c2410_nand_select_chip; 
    chip->chip_delay   = 50; 
    chip->priv       = nmtd; 
    chip->options       = 0; 
    chip->controller   = &info->controller; 
 
    switch (info->cpu_type) 
    { 
    case TYPE_S3C2410: 
        break; 
 
    case TYPE_S3C2440: 
        chip->IO_ADDR_W = regs + S3C2440_NFDATA; 
        info->sel_reg   = regs + S3C2440_NFCONT; 
        info->sel_bit    = S3C2440_NFCONT_nFCE; 
        /*初始化必须实现的几个函数*/ 
        chip->cmd_ctrl  = s3c2440_nand_hwcontrol; 
        chip->dev_ready = s3c2440_nand_devready; 
        chip->read_buf  = s3c2440_nand_read_buf; 
        chip->write_buf    = s3c2440_nand_write_buf; 
        break; 
 
    case TYPE_S3C2412: 
 
        break; 
    } 
 
    chip->IO_ADDR_R = chip->IO_ADDR_W; 
 
    nmtd->info       = info; 
    /*mtd 层调用mtd nand层的函数时将nand_chip数据传入*/ 
    nmtd->mtd.priv       = chip; 
    nmtd->mtd.owner    = THIS_MODULE; 
    nmtd->set       = set; 
 
    if (hardware_ecc) 
    { 
        chip->ecc.calculate = s3c2410_nand_calculate_ecc; 
        chip->ecc.correct   = s3c2410_nand_correct_data; 
        chip->ecc.mode        = NAND_ECC_HW; 
        .....
    } 
    else 
    { 
        chip->ecc.mode        = NAND_ECC_SOFT; 
    } 
 
    if (set->ecc_layout != NULL) 
        chip->ecc.layout = set->ecc_layout; 
 
    if (set->disable_ecc) 
        chip->ecc.mode    = NAND_ECC_NONE; 
}

/* Fill in remaining MTD driver data */ 
mtd->type = MTD_NANDFLASH; 
mtd->flags = MTD_CAP_NANDFLASH; 
mtd->erase = nand_erase; 
mtd->point = NULL; 
mtd->unpoint = NULL; 
mtd->read = nand_read; 
mtd->write = nand_write; 
mtd->read_oob = nand_read_oob; 
mtd->write_oob = nand_write_oob; 
mtd->sync = nand_sync; 
mtd->lock = NULL; 
mtd->unlock = NULL; 
mtd->suspend = nand_suspend; 
mtd->resume = nand_resume; 
mtd->block_isbad = nand_block_isbad; 
mtd->block_markbad = nand_block_markbad;

static int s3c2410_nand_add_partition(struct s3c2410_nand_info *info, 
                                      struct s3c2410_nand_mtd *mtd, 
                                      struct s3c2410_nand_set *set) 
{ 
    if (set == NULL) 
        return add_mtd_device(&mtd->mtd); 
 
    if (set->nr_partitions > 0 && set->partitions != NULL) 
    { 
        return add_mtd_partitions(&mtd->mtd, set->partitions, set->nr_partitions); 
    } 
 
    return add_mtd_device(&mtd->mtd); 
}