驱动程序

1 /*
2 * 参考:
3 * .linux-2.6.22.6driversmtddevicesmtdram.c
4 * .linux-2.6.22.6driversmtdmapsphysmap.c
5 */
6 #include
7 #include
8 #include
9 #include
10 #include
11 #include
12 #include
13 #include
14 #include
15 #include
16 #include
17 #include
18
19
20 static struct map_info *nor_map;
21 static struct mtd_info *nor_mtd;
22
23
24 //分区信息
25 static struct mtd_partition nor_parts[] = {
26         [0] = {
27                 .name         = "bootloader_nor",                        
28                 .size         = 0x00040000,                        
29                 .offset = 0,                                        /* offset within the master MTD space */
30         },
31
32         [1] = {
33                 .name         = "root_nor",                                
34                 .offset = MTDPART_OFS_APPEND,        //紧跟着上一个分区的大小
35                 .size         = MTDPART_SIZ_FULL,                
36         },
37 };
38
39
40
41 /* 1 出入口函数 */
42 static int __init nor_init(void)
43 {
44         /* 2 分配map_info结构体 */
45         nor_map = kmalloc(sizeof(struct map_info), GFP_KERNEL);
46         /******** 2 end ********/
47
48
49         /* 3 设置：物理基地址(phys)、大小(size)、位宽(bankwidth)、虚拟基地址(virt) */
50         nor_map->name = "nor";
51         nor_map->phys = 0;
52         nor_map->size = 1000000;        //16M,大于nor的实际大小
53         nor_map->bankwidth = 2;
54         nor_map->virt = ioremap(nor_map->phys, nor_map->size);
55
56         simple_map_init(nor_map);
57         /******** 3 end ********/
58
59
60         /* 4 使用：调用Nor Flash协议层提供的函数来识别 */
61         printk("use cfi_proben");
62         nor_mtd = do_map_probe("cfi_probe", nor_map);
63         if (!nor_mtd)
64         {
65                 printk("use jedec_proben");
66                 nor_mtd = do_map_probe("jedec_probe", nor_map);
67         }
68         
69         if (!nor_mtd)
70         {
71                 printk("failn");
72                 iounmap(nor_map->virt);
73                 kfree(nor_map);
74                 kfree(nor_mtd);
75                 return -EIO;
76         }
77         /******** 4 end ********/
78
79         /* 5 添加分区：add_mtd_partison */
80         add_mtd_partitions(nor_mtd, nor_parts, 2);
81         /******** 5 end ********/
82         return 0;
83 }
84
85
86 static void __exit nor_exit(void)
87 {
88         iounmap(nor_map->virt);
89         kfree(nor_map);
90         kfree(nor_mtd);
91         del_mtd_partitions(nor_mtd);
92         return;
93 }
94
95 module_init(nor_init);
96 module_exit(nor_exit);
97
98 MODULE_LICENSE("GPL");
99 /******** 1 end ********/

调试

测试1:通过配置内核支持NOR FLASH

1. make menuconfig

-> Device Drivers

-> Memory Technology Device (MTD) support

-> Mapping drivers for chip access

CFI Flash device in physical memory map

(0x0) Physical start address of flash mapping // 物理基地址

(0x1000000) Physical length of flash mapping // 长度

(2) Bank width in octets (NEW) // 位宽

2. make modules

cp drivers/mtd/maps/physmap.ko /work/nfs_root/first_fs

3. 启动开发板

ls /dev/mtd*

insmod physmap.ko

ls /dev/mtd*

cat /proc/mtd

测试2: 使用自己写的驱动程序:

1. ls /dev/mtd*

2. insmod s3c_nor.ko

3. ls /dev/mtd*

4. 格式化: flash_eraseall -j /dev/mtd1

5. mount -t jffs2 /dev/mtdblock1 /mnt

在/mnt目录下操作文件

NOR FLASH识别过程:

do_map_probe("cfi_probe", s3c_nor_map);

drv = get_mtd_chip_driver(name)

ret = drv->probe(map); // cfi_probe.c

cfi_probe

mtd_do_chip_probe(map, &cfi_chip_probe);

cfi = genprobe_ident_chips(map, cp);

genprobe_new_chip(map, cp, &cfi)

cp->probe_chip(map, 0, NULL, cfi)

cfi_probe_chip

// 进入CFI模式

cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);

// 看是否能读出"QRY"

qry_present(map,base,cfi)

.....

do_map_probe("jedec_probe", s3c_nor_map);

drv = get_mtd_chip_driver(name)

ret = drv->probe(map); // jedec_probe

jedec_probe

mtd_do_chip_probe(map, &jedec_chip_probe);

genprobe_ident_chips(map, cp);

genprobe_new_chip(map, cp, &cfi)

cp->probe_chip(map, 0, NULL, cfi)

jedec_probe_chip

// 解锁

cfi_send_gen_cmd(0xaa, cfi->addr_unlock1, base, map, cfi, cfi->device_type, NULL);

cfi_send_gen_cmd(0x55, cfi->addr_unlock2, base, map, cfi, cfi->device_type, NULL);

// 读ID命令

cfi_send_gen_cmd(0x90, cfi->addr_unlock1, base, map, cfi, cfi->device_type, NULL);

// 得到厂家ID，设备ID

cfi->mfr = jedec_read_mfr(map, base, cfi);

cfi->id = jedec_read_id(map, base, cfi);

// 和数组比较

jedec_table