Nand Flash 驱动框架

时间：2023-03-08 23:58:48
Nand Flash 驱动框架

框架入口源文件：s3c_nand.c

（可根据入口源文件，再按着框架到内核走一遍）

内核版本：linux_2.6.22.6   硬件平台：JZ2440

以下是驱动框架：

Nand Flash 驱动框架

以下是驱动代码 s3c_nand.c ：

#include <linux/module.h>

#include <linux/types.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/string.h>

#include <linux/ioport.h>

#include <linux/platform_device.h>

#include <linux/delay.h>

#include <linux/err.h>

#include <linux/slab.h>

#include <linux/clk.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/nand.h>

#include <linux/mtd/nand_ecc.h>

#include <linux/mtd/partitions.h>

#include <asm/io.h>

#include <asm/arch/regs-nand.h>

#include <asm/arch/nand.h>

//定义一个 nand_chip 结构体

static struct nand_chip *s3c_chip;

//定义一个 mtd_info 结构体

static struct mtd_info *s3c_info;

//定义寄存器结构体

static struct s3c_nand_regs

{

    unsigned long nfconf  ;

    unsigned long nfcont  ;

    unsigned long nfcmd   ;

    unsigned long nfaddr  ;

    unsigned long nfdata  ;

    unsigned long nfeccd0 ;

    unsigned long nfeccd1 ;

    unsigned long nfeccd  ;

    unsigned long nfstat  ;

    unsigned long nfestat0;

    unsigned long nfestat1;

    unsigned long nfmecc0 ;

    unsigned long nfmecc1 ;

    unsigned long nfsecc  ;

    unsigned long nfsblk  ;

    unsigned long nfeblk  ;

}*s3c_nand_regs;

//分区表

static struct mtd_partition s3c_partitions[] =

{

          [] = {

        .name   = "bootloader",

        .size   = 0x00040000,

        .offset    = ,

    },

    [] = {

        .name   = "params",

        .offset = MTDPART_OFS_APPEND,

        .size   = 0x00020000,

    },

    [] = {

        .name   = "kernel",

        .offset = MTDPART_OFS_APPEND,

        .size   = 0x00200000,

    },

    [] = {

        .name   = "root",

        .offset = MTDPART_OFS_APPEND,

        .size   = MTDPART_SIZ_FULL,

    }

};

static void s3c_select_chip(struct mtd_info *mtd, int chip)

{

    if (chip == -)        s3c_nand_regs->nfcont |= (<<);

    else        s3c_nand_regs->nfcont &= ~(<<);

}

int s3c_dev_ready(struct mtd_info *mtd)

{

    return (s3c_nand_regs->nfstat & (<<));

}

void s3c_cmd_ctrl(struct mtd_info *mtd, int dat,unsigned int ctrl)

{

    if (ctrl & NAND_CLE)        s3c_nand_regs->nfcmd = dat;

    else        s3c_nand_regs->nfaddr = dat;

}

static int s3c_nand_init(void)

{

   struct clk *clk;

   //申请 nand_chip

   s3c_chip = kzalloc(sizeof(struct nand_chip),GFP_KERNEL);

   //初始化 nand_chip 函数供扫描用           1.选中 2.状态 3.发地址和命令 5.发数据 6.读数据

   s3c_nand_regs = ioremap(0x4E000000,sizeof(struct s3c_nand_regs));

   s3c_chip->select_chip =s3c_select_chip;

   s3c_chip->dev_ready   =s3c_dev_ready;

   s3c_chip->cmd_ctrl    =s3c_cmd_ctrl;

   s3c_chip->IO_ADDR_R   =&s3c_nand_regs->nfdata;

   s3c_chip->IO_ADDR_W   =&s3c_nand_regs->nfdata;

   s3c_chip->ecc.mode    =NAND_ECC_SOFT;

   //初始化 读写时序NFCONF 开关FCONT           NAND时钟

   s3c_nand_regs->nfconf = (<<)|(<<)|(<<);

   s3c_nand_regs->nfcont = (<<) | (<<);

   clk =clk_get(NULL,"nand");

   clk_enable(clk);

   //申请 初始化 mtd_info

   s3c_info = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);

   s3c_info->priv = s3c_chip;

   s3c_info->owner = THIS_MODULE;

   //nand_scan           nand_chip --> mtd_info

    nand_scan(s3c_info,);  

   //add_mtd_partitions  mtd_info --> gendisk

   add_mtd_partitions(s3c_info, s3c_partitions,);

     return ;

}

static void s3c_nand_exit(void)

{

  iounmap(s3c_nand_regs);

  kfree(s3c_chip);

  kfree(s3c_info);

  del_mtd_partitions(s3c_info);

}

module_init(s3c_nand_init);

module_exit(s3c_nand_exit);

MODULE_LICENSE("GPL");

以下是编译驱动的Makefile：

KER_DIR=/work/systems/kernel/linux-/linux-2.6.22.6

all:

    make -C $(KER_DIR) M=`pwd` modules

clean:

    make -C $(KER_DIR) M=`pwd` modules clean

    rm -fr modules.order

obj-m += s3c_nand.o

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