2022年10月13日 | mini2440 简单nandflash驱动代码记录（2.6.32.2内核）

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static struct nand_chip *mini2440_nand;

static struct mtd_info *mini2440_mtd_info;

static struct nand_regs_t{

unsigned long NFCONF;

unsigned long NFCONT;

unsigned long NFCMD;

unsigned long NFADDR;

unsigned long NFDATA;

unsigned long NFMECCD0;

unsigned long NFMECCD1;

unsigned long NFSECCD;

unsigned long NFSTAT;

unsigned long NFESTAT0;

unsigned long NFESTAT1;

unsigned long NFMECC0;

unsigned long NFMECC1;

unsigned long NFSECC;

unsigned long NFSBLK;

unsigned long NFEBLK;

};

static volatile struct nand_regs_t *nand_regs;

static void grh_select_chip(struct mtd_info *mtd, int chipnr){

if(-1 == chipnr){ //取消选中nfcont[1] = 1

nand_regs->NFCONT |= (1<<1);

}

else{ //选中芯片 nfcont[1] = 0

nand_regs->NFCONT &= ~(1<<1);

}

}

static void grh_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl){

if(ctrl & NAND_CLE){ //发送命令 nfcmmd = dat

nand_regs->NFCMD = dat;

}

else{ //发送地址 nfaddr = dat

nand_regs->NFADDR = dat;

}

}

static int grh_dev_ready(struct mtd_info *mdt){

//return nfstat[0]

return nand_regs->NFSTAT &(1<<0);

}

//falsh分区表

static struct mtd_partition grh_nand_parts[] = {

[0] = {

.name = "grh_supervivi",

.size = 0x00040000,

.offset = 0,

},

[1] = {

.name = "grh_param",

.offset = 0x00040000,

.size = 0x00020000,

},

[2] = {

.name = "grh_Kernel",

.offset = 0x00060000,

.size = 0x00500000,

},

[3] = {

.name = "grh_root",

.offset = 0x00560000,

.size = 1024 * 1024 * 1024, //

},

[4] = {

.name = "grh_nand",

.offset = 0x00000000,

.size = 1024 * 1024 * 1024, //

}

};

static int nand_init(void){

struct clk *clk;

/*分配nand_chip结构体

  该结构体里面需要提供对nandflash的硬件操作(发命令，发数据，读数据，复位，选通等)的

  具体实现，mtd_info实现了怎么用命令来操作flash,而nand_chip就得在更低一层对命令进行实现

*/

mini2440_nand = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);

nand_regs = ioremap(0x4e000000, sizeof(struct nand_regs_t));

//设置参数

mini2440_nand->select_chip = grh_select_chip; //设置选中芯片的函数

mini2440_nand->cmd_ctrl = grh_cmd_ctrl; //设置发送命令和地址的函数

mini2440_nand->IO_ADDR_R = &(nand_regs->NFDATA); //nfdata虚拟地址

mini2440_nand->IO_ADDR_W = &(nand_regs->NFDATA); //nfdata虚拟地址

mini2440_nand->dev_ready = grh_dev_ready; //判断芯片是否就绪的函数

mini2440_nand->ecc.mode = NAND_ECC_SOFT; //软件生成ECC校验码，存入OOB区

//使能nandflash控制器的时钟,才能操作相关的寄存器

clk = clk_get(NULL, "nand");

clk_enable(clk);

//设置硬件相关的时间参数

nand_regs->NFCONF = 0<<12; //TACLS=0

nand_regs->NFCONF |= (1<<8); //TWRPH0=1

nand_regs->NFCONF |= (0<<4); //TWRPH1=0

nand_regs->NFCONT |= (1<<1); //先不选中芯片

nand_regs->NFCONT |= (1<<0); //使能nandflash控制器

//使用nand_chip

mini2440_mtd_info = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);

mini2440_mtd_info->owner = THIS_MODULE;

mini2440_mtd_info->priv = mini2440_nand;

//扫描识别芯片构造mtd_info结构体,mtd_info确定了对flash进行读写需要怎么发送命令

nand_scan(mini2440_mtd_info, 1); 

//add_mtd_partition划分flash的分区

add_mtd_partitions(mini2440_mtd_info , grh_nand_parts , 5);

return 0;

}

static void nand_exit(void){

iounmap(nand_regs);

kfree(mini2440_nand);

kfree(mini2440_mtd_info);

return ;

}

module_init(nand_init);

module_exit(nand_exit);

MODULE_AUTHOR("GRH");

MODULE_VERSION("1.0");

MODULE_DESCRIPTION("NAND FLASH DRIVER");

MODULE_LICENSE("GPL");

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原文链接：https://blog.csdn.net/xiaohaowudi_grh/article/details/38810601