nandflash驱动之添加MTD设备与测试

接着上面的驱动程序讲，现在就要添加分区了

使用这个函数





第一个参数是mtd_info结构体，如果你只想把整个flash当作一个分区，就直接使用add_mtd_device就可以了

第二个参数是mtd_partition结构体，这个指针就像个数组一样，然后这个数组有多少项呢，这就是第三个参数nbparts了

所以说我们要构造这个mtd_partition这个数组

我们来看一看原来这个数组的分区是怎么分的？？？



struct mtd_partition s3c_partition_info[] = {

{

.name = "uboot",

.offset
= 0, /* for bootloader */

.size = (1*SZ_1M),

.mask_flags
= MTD_CAP_NANDFLASH,

},

{

.name = "recovery",

.offset
= MTDPART_OFS_APPEND,

.size = (5*SZ_1M),

},

{

.name = "kernel",

.offset
= MTDPART_OFS_APPEND,

.size = (5*SZ_1M),

},

{

.name = "ramdisk",

.offset
= MTDPART_OFS_APPEND,

.size = (3*SZ_1M),

},

{

.name = "root",

.offset
= MTDPART_OFS_APPEND,

.size = MTDPART_SIZ_FULL,

},

};

MTDPART_OFS_APPEND表示紧更这上面这个分区

MTDPART_SIZ_FULL表示下面的所有空间都是root分区

代码如下

#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/cpufreq.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 <plat/regs-nand.h>

#include <plat/nand.h>

static struct nand_chip *nand;

static struct mtd_info *nand_mtd;

struct s5p_nand_regs{

unsigned long nfconf;

unsigned long nfcont;

unsigned long nfcmmd;

unsigned long nfaddr;

unsigned long nfdata;

unsigned long nfmeccd0;

unsigned long nfmeccd1;

unsigned long nfseccd;

unsigned long nfsblk;

unsigned long nfeblk;

unsigned long nfstat;

unsigned long nfeccerr0;

unsigned long nfeccerr1;

};

static struct s5p_nand_regs *s5p_nand_regs;

struct mtd_partition s5p_partition_info[] = {

{

.name = "uboot",

.offset
= 0, /* for bootloader */

.size = (1*SZ_1M),

.mask_flags
= MTD_CAP_NANDFLASH,

},

{

.name = "recovery",

.offset
= MTDPART_OFS_APPEND,

.size = (5*SZ_1M),

},

{

.name = "kernel",

.offset
= MTDPART_OFS_APPEND,

.size = (5*SZ_1M),

},

{

.name = "ramdisk",

.offset
= MTDPART_OFS_APPEND,

.size = (3*SZ_1M),

},

{

.name = "root",

.offset
= MTDPART_OFS_APPEND,

.size = MTDPART_SIZ_FULL,

},

};

static void gh_select_chip(struct mtd_info *mtd, int chipnr)

{

if(chipnr == -1)

{

//取消选中 将NFCONT[1] 设置为1

s5p_nand_regs->nfcont |=(1<<1);

}

else

{

//选中 NFCONT【1】设置为0

s5p_nand_regs->nfcont &= ~(1<<1);

}

}

static void gh_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)

{

if (ctrl & NAND_CLE)

{

//发命令 NFCMD寄存器 = cmd的值

s5p_nand_regs->nfcmmd = cmd;

}

else

{

//发地址 NFADDR寄存器=cmd的值

s5p_nand_regs->nfaddr = cmd;

}

}

static int gh_dev_ready(struct mtd_info *mtd)

{

return (s5p_nand_regs->nfstat & (1<<0));

}

static int nand_init(void)

{

struct clk *nand_clk;

/*1.分配一个nand_chip结构体*/

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

/*2.设置*/

s5p_nand_regs = ioremap(0xb0e00000,sizeof(struct s5p_nand_regs));

//设置nand_chip是给nand_scan_ident函数用的，如果不知道怎么设置，先看nand_scan_ident怎么使用*/

//它应该提供发命令，发地址，发数据，读数据，判断状态的功能

nand->select_chip = gh_select_chip;

nand->cmd_ctrl =
gh_cmd_ctrl;

nand->dev_ready = gh_dev_ready;

nand->IO_ADDR_R = &s5p_nand_regs->nfdata;

nand->IO_ADDR_W = &s5p_nand_regs->nfdata;

nand->ecc.mode = NAND_ECC_SOFT;

/*硬件相关的操作*/

/*3.硬件相关*/

/*使能时钟*/

nand_clk = clk_get(NULL, "nand");

clk_enable(nand_clk);

/*设置时钟*/

//hclk是166.75Mhz,就是16.675ns

#define TWRPH1 1

#define TWRPH0 1

#define TACLS 1

s5p_nand_regs->nfconf |= (TACLS<<12) | (TWRPH0<<8) | (TWRPH1<<4);

/*

* AddrCycle[1]:1 = 发送地址需要5个周期

*/

s5p_nand_regs->nfconf |= 1<<1;

/*

* MODE[0]:1 = 使能Nand Flash控制器

* Reg_nCE0[1]:1 = 取消片选

*/

s5p_nand_regs->nfcont |= (1<<1)|(1<<0);

/*3.使用*/

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

//将mtd_info与nandchip相联系起来

nand_mtd->owner = THIS_MODULE;

nand_mtd->priv = nand;

nand_scan(nand_mtd, 1);

/*4.添加分区*/

add_mtd_partitions(nand_mtd,s5p_partition_info,5);

return 0;

}

static void nand_exit(void)

{

del_mtd_partitions(nand_mtd);

kfree(nand);

iounmap(s5p_nand_regs);

kfree(nand_mtd);

}

module_init(nand_init);

module_exit(nand_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("EIGHT");

测试：

1. make menuconfig 去掉内核自带的nand flash驱动

在内核目录下的

-----driver

----mtddevice

-----nandflash device support



把这个去掉

使用新内核驱动，并且使用nfs作为跟文件系统，因为你已经把nand flash驱动给去掉了，