/* 参考
* drivers\mtd\nand\at91_nand.c
* drivers\mtd\nand\s3c2410.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>
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 ;
};
static struct mtd_partition s3c_nand_parts[] = {
[0] = {
.name = "uboot",
.size = 0x00040000,
.offset = 0,
},
[1] = {
.name = "params",
.offset = MTDPART_OFS_APPEND,
.size = 0x00020000,
},
[2] = {
.name = "kernel",
.offset = MTDPART_OFS_APPEND,
.size = 0x00200000,
},
[3] = {
.name = "rootfs",
.offset = MTDPART_OFS_APPEND,
.size = MTDPART_SIZ_FULL,
}
};
static struct s3c_nand_regs *s3c_nand_regs;
static struct nand_chip *s3c_nand_chip;
static struct mtd_info *s3c_mtd_info;
#define S3C_MAX_CHIP 1
static void s3c2440_select_chip(struct mtd_info *mtd, int chipnr)
{
switch (chipnr)
{
case -1:
/* 取消片选 NFCONT[1]=1 */
s3c_nand_regs->nfcont |= (1<<1);
break;
case 0:
/* 选中 NFCONT[1]=0 */
s3c_nand_regs->nfcont &= ~(1<<1);
break;
default:
break;
}
}
static void s3c2440_cmd_ctrl(struct mtd_info *mtd, int cmd_or_addr, unsigned int ctrl)
{
if (cmd_or_addr == NAND_CMD_NONE)
return;
if (ctrl & NAND_CLE)
{
/* 发命令 NFCMD = cmd_or_addr */
s3c_nand_regs->nfcmd = cmd_or_addr;
}
else
{
/* 发地址 NFADDR = cmd_or_addr */
s3c_nand_regs->nfaddr = cmd_or_addr;
}
}
static int s3c2440_dev_ready(struct mtd_info *mtd)
{
/* 判断 NFSTAT[0] */
return (s3c_nand_regs->nfstat & (1<<0));
}
static int s3c_nand_init(void)
{
struct clk *s3c_nand_clk;
/* 1. 分配一个nand_chip结构体 */
s3c_nand_chip = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
s3c_nand_regs = ioremap(0x4E000000, sizeof(struct s3c_nand_regs));
/* 2. 设置nand_chip */
/* 分配的nand_chip是给nand_scan用的,所以可以先看nand_scan是如何使用的 */
s3c_nand_chip->select_chip = s3c2440_select_chip;
s3c_nand_chip->cmd_ctrl = s3c2440_cmd_ctrl;
/* "NFDATA的虚拟地址"; 注意这里要取址符 */
s3c_nand_chip->IO_ADDR_R = &s3c_nand_regs->nfdata;
/* "NFDATA的虚拟地址"; */
s3c_nand_chip->IO_ADDR_W = &s3c_nand_regs->nfdata;
s3c_nand_chip->dev_ready = s3c2440_dev_ready;
s3c_nand_chip->ecc.mode = NAND_ECC_SOFT; /* enable ECC */
/* 3. 硬件相关的设置 */
/* 使能NAND FLASH控制器的时钟 */
s3c_nand_clk = clk_get(NULL, "nand");
/* 实际上就是设置CLKCON寄存器的bit4 */
clk_enable(s3c_nand_clk);
#define TACLS 0
#define TWRPH0 1
#define TWRPH1 0
s3c_nand_regs->nfconf = (TWRPH1<<4) | (TWRPH0<<8) | (TACLS<<12);
/*
* NFCONT
* BIT1=1,取消片选
* BIT0=1,使能NAND FLASH控制器
*/
s3c_nand_regs->nfcont = (1<<1) | (1<<0);
/* 4. 使用nand_scan */
s3c_mtd_info = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
s3c_mtd_info->priv = s3c_nand_chip;
s3c_mtd_info->owner = THIS_MODULE;
/* 扫描识别NAND FLASH */
nand_scan(s3c_mtd_info, S3C_MAX_CHIP);
/* 5. add_mtd_patitions */
/* 如果不想分区的话用add_mtd_device就够了 有4个分区所以 nbparts=4 */
add_mtd_partitions(s3c_mtd_info, s3c_nand_parts, 4);
return 0;
}
static void s3c_nand_exit(void)
{
iounmap(s3c_nand_regs);
del_mtd_partitions(s3c_mtd_info);
kfree(s3c_nand_chip);
kfree(s3c_mtd_info);
}
module_init(s3c_nand_init);
module_exit(s3c_nand_exit);
MODULE_LICENSE("GPL");
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