fl2440的U-boot-2010.09移植（五）uboot架构中NAND Flash驱动修改

       uboot代码中的NAND Flash的读写驱动中存在一些错误，需要进行修改后才能完成，主要修改drivers/mtd/nand/s3c2410_nand.c文件，首先修改27行如下：

#define NF_BASE         0x4e000000

#if defined(CONFIG_S3C2410)
#define S3C2410_NFCONF_EN          (1<<15)
#define S3C2410_NFCONF_512BYTE     (1<<14)
#define S3C2410_NFCONF_4STEP       (1<<13)
#define S3C2410_NFCONF_INITECC     (1<<12)
#define S3C2410_NFCONF_nFCE        (1<<11)
#define S3C2410_NFCONF_TACLS(x)    ((x)<<8)
#define S3C2410_NFCONF_TWRPH0(x)   ((x)<<4)
#define S3C2410_NFCONF_TWRPH1(x)   ((x)<<0)

#define S3C2410_ADDR_NALE 4
#define S3C2410_ADDR_NCLE 8
#endif

#if defined(CONFIG_S3C2440)
#define S3C2410_NFCONT_EN          (1<<0)
#define S3C2410_NFCONT_INITECC     (1<<4)
#define S3C2410_NFCONT_nFCE        (1<<1)
#define S3C2410_NFCONT_MAINECCLOCK (1<<5)
#define S3C2410_NFCONF_TACLS(x)    ((x)<<12)
#define S3C2410_NFCONF_TWRPH0(x)   ((x)<<8)
#define S3C2410_NFCONF_TWRPH1(x)   ((x)<<4)

#define S3C2410_ADDR_NALE 0x08
#define S3C2410_ADDR_NCLE 0x0c
#endif

u-boot.2010.09自带的S3C2410_nand.c的s3c2410_hwcontrol函数有错。在此函数中，把chip->IO_ADDR_W值改写了，导致在写数据时出现错误。解决方法是使用一全局变量代替 chip->IO_ADDR_W。在 s3c2410_hwcontrol 函数上一行定义这个全局变量，然后修改 s3c2410_hwcontrol 函数（修改71行），让它支持 S3C2440，如下：

ulong IO_ADDR_W = NF_BASE;
static void s3c2410_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
{
	//struct nand_chip *chip = mtd->priv;
	struct s3c2410_nand *nand = s3c2410_get_base_nand();

	debugX(1, "hwcontrol(): 0x%02x 0x%02x\n", cmd, ctrl);

	if (ctrl & NAND_CTRL_CHANGE) {
		//ulong IO_ADDR_W = (ulong)nand;
                IO_ADDR_W = (ulong)nand;

		if (!(ctrl & NAND_CLE))
			IO_ADDR_W |= S3C2410_ADDR_NCLE;
		if (!(ctrl & NAND_ALE))
			IO_ADDR_W |= S3C2410_ADDR_NALE;

		//chip->IO_ADDR_W = (void *)IO_ADDR_W;

#if defined(CONFIG_S3C2410)
		if (ctrl & NAND_NCE)
			writel(readl(&nand->NFCONF) & ~S3C2410_NFCONF_nFCE,
			       &nand->NFCONF);
		else
			writel(readl(&nand->NFCONF) | S3C2410_NFCONF_nFCE,
			       &nand->NFCONF);
#endif

#if defined(CONFIG_S3C2440)
		if (ctrl & NAND_NCE)
			writel(readl(&nand->NFCONT) & ~S3C2410_NFCONT_nFCE,
			       &nand->NFCONT);
		else
			writel(readl(&nand->NFCONT) | S3C2410_NFCONT_nFCE,
			       &nand->NFCONT);
#endif
	}

	if (cmd != NAND_CMD_NONE)
		//writeb(cmd, chip->IO_ADDR_W);
                writeb(cmd, (void *)IO_ADDR_W);
}

然后修改函数s3c2410_nand_enable_hwecc如下：

void s3c2410_nand_enable_hwecc(struct mtd_info *mtd, int mode)
{
	struct s3c2410_nand *nand = s3c2410_get_base_nand();
	debugX(1, "s3c2410_nand_enable_hwecc(%p, %d)\n", mtd, mode);
#if defined(CONFIG_S3C2410)
	writel(readl(&nand->NFCONF) | S3C2410_NFCONF_INITECC, &nand->NFCONF);
#endif

#if defined(CONFIG_S3C2440)
	writel(readl(&nand->NFCONT) | S3C2410_NFCONT_INITECC, &nand->NFCONT);
#endif
}

最后修改board_nand_init 函数如下：

int board_nand_init(struct nand_chip *nand)
{
	u_int32_t cfg;
	u_int8_t tacls, twrph0, twrph1;
	struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
	struct s3c2410_nand *nand_reg = s3c2410_get_base_nand();

	debugX(1, "board_nand_init()\n");

	writel(readl(&clk_power->CLKCON) | (1 << 4), &clk_power->CLKCON);

#if defined(CONFIG_S3C2410)
	/* initialize hardware */
	twrph0 = 3;
	twrph1 = 0;
	tacls = 0;

	cfg = S3C2410_NFCONF_EN;
	cfg |= S3C2410_NFCONF_TACLS(tacls - 1);
	cfg |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
	cfg |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
	writel(cfg, &nand_reg->NFCONF);

	/* initialize nand_chip data structure */
	nand->IO_ADDR_R = nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;
#endif

#if defined(CONFIG_S3C2440)
	/* initialize hardware */
	tacls = 0;
        twrph0 = 4;
	twrph1 = 2;


        cfg = 0; 
        cfg |= S3C2410_NFCONF_TACLS(tacls - 1); 
        cfg |= S3C2410_NFCONF_TWRPH0(twrph0 - 1); 
        cfg |= S3C2410_NFCONF_TWRPH1(twrph1 - 1); 
        writel(cfg, &nand_reg->NFCONF); 

        cfg = (0<<13)|(0<<12)|(0<<10)|(0<<9)|(0<<8)|(0<<6)|(0<<5)|(1<<4)|(0<<1)|(1<<0); 
        writel(cfg, &nand_reg->NFCONT); 
        /* initialize nand_chip data structure */ 
        nand->IO_ADDR_R = nand->IO_ADDR_W = (void *)&nand_reg->NFDATA;
#endif

	nand->select_chip = NULL;
……