一、移植前的修改
1.1 include/configs/jz2440修改
原来的定义：
可以看出，要先定义CONFIG_CMD_NAND才能使能NANDFlash。
这个在我们文件中的82行有定义，所以不需要定义了。
将里面的S3C2410全部改为S3C2440：
1.2 drivers/mtd/nand/修改
拷贝s3c2410_nand.c 成 s3c2440_nand.c
在此目录的makefile中添加 s3c2440_nand.c
修改s3c2440_nand.c 文件，从board_nand_init 逐行检测修改，代码如下：
1 #include <common.h>
2
3 #include <nand.h>
4 #include <asm/arch/s3c24x0_cpu.h>
5 #include <asm/io.h>
6
7 /* NFCONF 寄存器定义 */
8 #define S3C2440_NFCONF_EN (1<<15)
9 #define S3C2440_NFCONF_512BYTE (1<<14)
10 #define S3C2440_NFCONF_4STEP (1<<13)
11 #define S3C2440_NFCONF_INITECC (1<<12)
12 #define S3C2440_NFCONF_nFCE (1<<1)
13 #define S3C2440_NFCONF_TACLS(x) ((x)<<12)
14 #define S3C2440_NFCONF_TWRPH0(x) ((x)<<8)
15 #define S3C2440_NFCONF_TWRPH1(x) ((x)<<4)
16
17 /* NFCONF 寄存器定义 */
18 #define S3C2440_NFCONT_LOCKTIGHT (1<<13)
19 #define S3C2440_NFCONT_SOFTLOCK (1<<12)
20 #define S3C2440_NFCONT_ENLLLEGALINT (1<<10)
21 #define S3C2440_NFCONT_ENRnBINT (1<<9)
22 #define S3C2440_NFCONT_Rn (1<<8)
23 #define S3C2440_NFCONT_SPAREECCLOCK (1<<6)
24 #define S3C2440_NFCONT_MAINECCLOCK (1<<5)
25 #define S3C2440_NFCONT_ECC (1<<4)
26 #define S3C2440_NFCONT_nCE (1<<1)
27 #define S3C2440_NFCONT_MODE (1<<0)
28
29
30
31
32 #define S3C2440_ADDR_NALE 4
33 #define S3C2440_ADDR_NCLE 8
34
35 #ifdef CONFIG_NAND_SPL
36
37 /* in the early stage of NAND flash booting, printf() is not available */
38 #define printf(fmt, args...)
39
40 static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
41 {
42 int i;
43 struct nand_chip *this = mtd->priv;
44
45 for (i = 0; i < len; i++)
46 buf[i] = readb(this->IO_ADDR_R);
47 }
48 #endif
49
50 /* ctrl:表示做什么，选中芯片/取消片选，是发命令还是发地址
51 * cmd :命令值或地址值
52 */
53 static void s3c24x0_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
54 {
55 struct s3c24x0_nand *nand = s3c24x0_get_base_nand();
56
57 debug("hwcontrol(): 0x%02x 0x%02x
", cmd, ctrl);
58
59 if (ctrl & NAND_CLE) {
60 /* 发命令 */
61 writeb(cmd, &nand->nfcmd);
62 }
63 else if (ctrl & NAND_ALE) {
64 /* 发地址 */
65 writeb(cmd, &nand->nfaddr);
66 }
67
68 }
69
70 /**
71 * nand_select_chip - [DEFAULT] control CE line
72 * @mtd: MTD device structure
73 * @chipnr: chipnumber to select, -1 for deselect
74 *
75 * Default select function for 1 chip devices.
76 */
77 void s3c2440_nand_select(struct mtd_info *mtd, int chipnr)
78 {
79 struct s3c24x0_nand *nand = s3c24x0_get_base_nand();
80
81 switch (chipnr) {
82 case -1: /* 取消选中 */
83 nand->nfcont |= S3C2440_NFCONT_nCE;
84 break;
85 case 0: /* 选中 */
86 nand->nfcont &= ~S3C2440_NFCONT_nCE;
87 break;
88
89 default:
90 BUG();
91 }
92 }
93
94 static int s3c24x0_dev_ready(struct mtd_info *mtd)
95 {
96 struct s3c24x0_nand *nand = s3c24x0_get_base_nand();
97 debug("dev_ready
");
98 return readl(&nand->nfstat) & 0x01;
99 }
100
101 #ifdef CONFIG_S3C2440_NAND_HWECC
102 void s3c24x0_nand_enable_hwecc(struct mtd_info *mtd, int mode)
103 {
104 struct s3c24x0_nand *nand = s3c24x0_get_base_nand();
105 debug("s3c24x0_nand_enable_hwecc(%p, %d)
", mtd, mode);
106 writel(readl(&nand->nfconf) | S3C2440_NFCONF_INITECC, &nand->nfconf);
107 }
108
109 static int s3c24x0_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
110 u_char *ecc_code)
111 {
112 struct s3c24x0_nand *nand = s3c24x0_get_base_nand();
113 ecc_code[0] = readb(&nand->nfecc);
114 ecc_code[1] = readb(&nand->nfecc + 1);
115 ecc_code[2] = readb(&nand->nfecc + 2);
116 debug("s3c24x0_nand_calculate_hwecc(%p,): 0x%02x 0x%02x 0x%02x
",
117 mtd , ecc_code[0], ecc_code[1], ecc_code[2]);
118
119 return 0;
120 }
121
122 static int s3c24x0_nand_correct_data(struct mtd_info *mtd, u_char *dat,
123 u_char *read_ecc, u_char *calc_ecc)
124 {
125 if (read_ecc[0] == calc_ecc[0] &&
126 read_ecc[1] == calc_ecc[1] &&
127 read_ecc[2] == calc_ecc[2])
128 return 0;
129
130 printf("s3c24x0_nand_correct_data: not implemented
");
131 return -1;
132 }
133 #endif
134
135 int board_nand_init(struct nand_chip *nand)
136 {
137 u_int32_t cfg = 0;
138 u_int8_t tacls, twrph0, twrph1;
139 struct s3c24x0_clock_power *clk_power = s3c24x0_get_base_clock_power();
140 struct s3c24x0_nand *nand_reg = s3c24x0_get_base_nand();
141
142 writel(readl(&clk_power->clkcon) | (1 << 4), &clk_power->clkcon);
143
144 /* 时序设置 */
145 tacls = 4;
146 twrph0 = 8;
147 twrph1 = 8;
148
149 /* 初始化时序 */
150 cfg |= S3C2440_NFCONF_TACLS(tacls - 1);
151 cfg |= S3C2440_NFCONF_TWRPH0(twrph0 - 1);
152 cfg |= S3C2440_NFCONF_TWRPH1(twrph1 - 1);
153 writel(cfg, &nand_reg->nfconf);
154
155 /* 使能NANDFLASH控制器，初始化ECC，禁止片选 */
156 writel(S3C2440_NFCONT_MODE | S3C2440_NFCONT_nCE | S3C2440_NFCONT_ECC, &nand_reg->nfcont);
157
158 /* initialize nand_chip data structure */
159 nand->IO_ADDR_R = (void *)&nand_reg->nfdata;
160 nand->IO_ADDR_W = (void *)&nand_reg->nfdata;
161
162 nand->select_chip = s3c2440_nand_select;
163
164 /* hwcontrol always must be implemented */
165 nand->cmd_ctrl = s3c24x0_hwcontrol;
166
167 nand->dev_ready = s3c24x0_dev_ready;
168
169 #ifdef CONFIG_S3C2410_NAND_HWECC
170 nand->ecc.hwctl = s3c24x0_nand_enable_hwecc;
171 nand->ecc.calculate = s3c24x0_nand_calculate_ecc;
172 nand->ecc.correct = s3c24x0_nand_correct_data;
173 nand->ecc.mode = NAND_ECC_HW;
174 nand->ecc.size = CONFIG_SYS_NAND_ECCSIZE;
175 nand->ecc.bytes = CONFIG_SYS_NAND_ECCBYTES;
176 nand->ecc.strength = 1;
177 #else
178 nand->ecc.mode = NAND_ECC_SOFT;
179 #endif
180
181 #ifdef CONFIG_S3C2440_NAND_BBT
182 nand->bbt_options |= NAND_BBT_USE_FLASH;
183 #endif
184
185 return 0;
186 }
修改过程如下：
1 u-boot-2016.05commonoard_r：board_init_r函数中的初始化序列init_sequence_r中的：
2 initr_nand
3 nand_init
4 nand_init_chip
5 board_nand_init
6 设置nand_chip结构体, 提供底层的操作函数
7 nand_scan
8 nand_scan_ident
9 nand_set_defaults
10 chip->select_chip = nand_select_chip;
11 chip->cmdfunc = nand_command;
12 chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
13
14 nand_get_flash_type
15 chip->select_chip
16 chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
17 nand_command() // 即可以用来发命令，也可以用来发列地址(页内地址)、行地址(哪一页)
18 chip->cmd_ctrl
19 s3c24x0_hwcontrol
20
21 chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
22 *maf_id = chip->read_byte(mtd);
23 *dev_id = chip->read_byte(mtd);
编译运行 结果如下：
测试：
执行写，在写之前注意一定要先擦除nandflash：
将 SDRAM 的 0x31e00000 地址的 0xff 字节数据写到 NAND FLASH 的 0 地址
执行读：从 NAND FLASH 的 0 地址读 0xff 字节数据到 SDRAM 的 0x31f00000 地址
比较：
