NAND Flash Driver

Hardware Principle and Analysis

Pin Description

Operate Nand Flash on U-BOOT

NAND FLASH S3C2440

Send command to select chip

CLE is set to high level NFCMMD = command value

Output command value on DATA0~DATA7

Send a write pulse

Send address to select chip NFADDR=address value

ALE is set high

Output address value on DATA0~DATA7

Send a write pulse

Send data to selected chip NFDATA=data value

ALE, CLE set to low level

Output data value on DATA0~DATA7

Send a write pulse

Read data and select chip val=NFDATA

Send out read pulse

Read data from DATA0 to DATA7

OpenJTAG> help md

md [.b, .w, .l] address [# of objects]

- memory display

OpenJTAG> help mw

mw [.b, .w, .l] address value [count]

- write memory

•b 1 byte

•W 2 bytes

• 4 bytes

1. Read ID

2. Read content: read the data at address 0

Use UBOOT command:

nand dump 0

Page 00000000 dump:

17 00 00 ea 14 f0 9f e5 14 f0 9f e5 14 f0 9f e5

The role of ECC

S3C2440-Nand Flash Controller Register

S3C2440-Nand Flash Memory Timing

K9F2G08U0C-Key Characteristic

K9F2G08U0C-Operation Timing

Drivers

driver.c

1 /*
2 * SAMSUNG: K9F2G08U0C
3 * 参考：
4 * .linux-2.6.22.6driversmtdnands3c2410.c
5 * .linux-2.6.22.6driversmtdnandat91_nand.c
6 */
7 #include
8 #include
9 #include
10 #include
11 #include
12 #include
13 #include
14 #include
15 #include
16 #include
17 #include
18
19 #include
20 #include
21 #include
22 #include
23
24 #include
25
26 #include
27 #include
28
29 struct regs_nand {
30         unsigned long         NFCONF;
31         unsigned long        NFCONT;
32         unsigned long        NFCMMD;
33         unsigned long        NFADDR;
34         unsigned long        NFDATA;
35         unsigned long        NFMECCD0;
36         unsigned long        NFMECCD1;
37         unsigned long        NFSECCD;
38         unsigned long        NFSTAT;
39         unsigned long        NFESTAT0;
40         unsigned long        NFESTAT1;
41         unsigned long        NFMECC0;
42         unsigned long        NFMECC1;
43         unsigned long        NFSECC;
44         unsigned long        NFSBLK;
45         unsigned long        NFEBLK;
46 };
47
48 static struct nand_chip *nand;
49 static struct mtd_info *mtd;
50 static struct regs_nand *regs_nand;
51
52 //分区信息
53 static struct mtd_partition nand_parts[] = {
54         [0] = {
55                 .name         = "bootloader",
56                 .size         = 0x00040000,
57                 .offset = 0,                                        /* offset within the master MTD space */
58         },
59
60         [1] = {
61                 .name         = "params",
62                 .offset = MTDPART_OFS_APPEND,        //紧跟着上一个分区的大小
63                 .size         = 0x00020000,
64         },
65
66 [2] = {
67 .name = "kernel",
68 .offset = MTDPART_OFS_APPEND, //Following the size of the previous partition
69 .size = 0x00200000,
70 },
71
72 [3] = {
73 .name = "root",
74 .offset = MTDPART_OFS_APPEND, //Following the size of the previous partition
75 .size = MTDPART_SIZ_FULL,
76 },
77 };
78
79 static void nand_select_chip(struct mtd_info *mtd, int chipnr)
80 {
81 if (chipnr == -1)
82 {
83 //Uncheck: NFCONT[1]:0
84 regs_nand->NFCONT |= (1<<1);
85 }
86 else {
87 //Select: NFCONT[1]:1
88 regs_nand->NFCONT &= ~(1<<1);
89 }
90 return;
91 }
92
93 static void nand_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
94 {
95 if (ctrl & NAND_CLE)
96 {
97 //Send command ：NFCMMD=dat
98 regs_nand->NFCMMD = dat;
99 }
100 else
101 {
102 //Sending address: NFADDR=dat
103 regs_nand->NFADDR = dat;
104 }
105 return;
106 }
107
108 static int nand_dev_ready(struct mtd_info *mtd)
109 {
110 return (regs_nand->NFSTAT & (1<<0));
111 }
112
113
114 /* 1 Entrance and exit functions*/
115 static int __init nand_init(void)
116 {
117 struct clk *clk;
118
119 /* 2 Allocate a nand_chip structure*/
120 nand = kzalloc(sizeof(struct nand_chip), GFP_KERNEL);
121 /******** 2 end ********/
122
123 regs_nand = ioremap(0x4E000000, sizeof(struct regs_nand));
124
125 /* 3 Setting: nand_chip */
126 //Provide: select, send command, send address, send data, read data, judge status function
127 nand->select_chip = nand_select_chip; //Chip select
128 nand->cmd_ctrl = nand_cmd_ctrl; //Send command
129 nand->IO_ADDR_R = ®s_nand->NFDATA; //Read
130 nand->IO_ADDR_W = ®s_nand->NFDATA; //Write
131 nand->dev_ready = nand_dev_ready; //Flash status (busy/idle)
132 nand->ecc.mode = NAND_ECC_SOFT; //ecc software check
133 /******** 3 end ********/
134
135 /* 4 Hardware related operations: timing*/
136 //Enable clock
137 clk = clk_get(NULL, "nand");
138 clk_enable(clk);
139
140 #define TACLS 0
141 #define TWRPH0 1
142 #define TWRPH1 0
143 //Time parameter setting
144 regs_nand->NFCONF = (TACLS<<12) | (TWRPH0<<8) | (TWRPH1<<4);
145
146 //Control---Enable nand flash controller, cancel chip select
147 regs_nand->NFCONT = (1<<0) | (1<<1);
148 /******** 4 end ********/
149
150
151 /* 5 Use: nand_scan */
152 mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
153 mtd->owner = THIS_MODULE;
154 mtd->priv = nand; //Private data
155
156 nand_scan(mtd, 1); //Identify nand_flash, construct mtd_info structure
157 /******** 5 end ********/
158
159
160 /* 6 Add partitions: add_mtd_partitions */
161 add_mtd_partitions(mtd, nand_parts, 4);
162
163 //No partitioning situation
164 //add_mtd_device(mtd);
165 /******** 6 end ********/
166
167 return 0;
168 }
169
170 static void __exit nand_exit(void)
171 {
172 del_mt d_partitions(mtd);
173 kfree(nand);
174 kfree(mtd);
175 iounmap(regs_nand);
176 return;
177 }
178
179 module_init(nand_init);
180 module_exit(nand_exit);
181 MODULE_LICENSE("GPL");
182 /******** 1 end ********/