NOR Flash驱动
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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 <linux/module.h>
7 #include <linux/types.h>
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/slab.h>
11 #include <linux/device.h>
12 #include <linux/platform_device.h>
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/map.h>
15 #include <linux/mtd/partitions.h>
16 #include <linux/mtd/physmap.h>
17 #include <asm/io.h>
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_probe
");
62 ????????nor_mtd = do_map_probe("cfi_probe", nor_map);
63 ????????if (!nor_mtd)
64 ????????{
65 ????????????????printk("use jedec_probe
");
66 ????????????????nor_mtd = do_map_probe("jedec_probe", nor_map);
67 ????????}
68 ????????
69 ????????if (!nor_mtd)
70 ????????{
71 ????????????????printk("fail
");
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 ********/
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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
<M> 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
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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
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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
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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)
.....
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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);
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// 读ID命令
cfi_send_gen_cmd(0x90, cfi->addr_unlock1, base, map, cfi, cfi->device_type, NULL);
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// 得到厂家ID，设备ID
cfi->mfr = jedec_read_mfr(map, base, cfi);
cfi->id = jedec_read_id(map, base, cfi);
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// 和数组比较
jedec_table
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