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;
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