mini2440 Norflash驱动移植过程

我不知道友善linux2.6.32的内核是否支持了mini2440的norflash，我在这里还是亲自的把mini2440的norflash支持上。移植过程分享如下：
            

一.添加配置项
1、修改 drivers/mtd/maps/Kconfig文件,在config_EDB7312配置项下添加如下内容:
config MTD_MINI2440
tristate"CFIFlashdevicemappedonMINI2440"
dependsARM&&MTD_CFI
help
ThisenablesaccesstotheCFICogent2440board.
Ifyouhavesuchaboard,say'Y'here.
2drivers/mtd/maps/Makefileobj-$(CONfig_MTD_EDB7312)+= edb7312.o下:
obj-$(CONfig_MTD_MINI2440)+=mini2440.o
3、复制驱动文件mini2440.c到drivers/mtd/maps目录下

二.配置编译内核
#makemenuconfig
以下内容必选:
MemoryTechnologyDevices(MTD)-->
<*>MemoryDevice(MTD)support
[*]MTDpartitioningsupport
   <*>DirectcharMTDdevices
   <*>Cachingblockdevices
RAM/ROM/Flashchipdrivers-->
   <*>DetectflashchipsbyCommonInterface(CFI)probe
   <*>SupportforInter/Sharpchips

   <*> Supportfor AMD/Fujitsu/Sp ansion flash chips

   <*>CFImini2440

下列内容(在flash上架fat16/fat32/ntfs/ext2等文件系统时才需要选上)不要选，否则会出现加载驱动模块时会出现ftl_cs:FTL header not found.
DeviceDrivers ->
  Memory Technology Devices (MTD) ->
      <>FTL (Flash Translation Layer) support
       <> NFTL(NAND Flash Translation Layer) support
       <>INFTL(Inverse NAND Flash Translation Layer) support

三.根据edb7312单板的norflash驱动(linux/mtd/maps/edb7312.c)来写mini2440的norflash驱动

代码在中(带详细注释)

1. /*支持单板:mini2440
2.  *支持内核:3.1.2版本
3.  *模仿驱动:/linux/drivers/mtd/maps/edb7312.c
4.  */
6. #include <linux/module.h>
7. #include <linux/types.h>
8. #include <linux/kernel.h>
9. #include <linux/init.h>
10. #include <asm/io.h>
11. #include <linux/mtd/mtd.h>
12. #include <linux/mtd/map.h>
13. #include <linux/mtd/partitions.h>
14. #define WINDOW_ADDR 0x00000000     /* nor FLASH物理地址 */
15. #define WINDOW_SIZE 0x00200000         /* nor FLASH大小 */
16. #define BUSWIDTH    2 /*估计是2Byte*/
17. /* 探测的接口类型，可以是"cfi_probe","jedec_probe","map_rom",NULL }; */
18. #define PROBETYPES { "cfi_probe",NULL }
19. #define MSG_PREFIX "MINI2440-nor:"   /*printk的前缀 */
20. #define MTDID      "mini2440-nor"    /*MTD驱动*/
21. static struct mtd_info *mymtd;
22. /*定义一个map_info，代表一块norflash*/
23. struct map_info mini2440nor_map =
24. {
25.         .name = "nor flash on MINI2440",
26.         .size = WINDOW_SIZE,serif; list-style-type:decimal-leading-zero; padding-right:1em">         .bankwidth = BUSWIDTH,serif; list-style-type:decimal-leading-zero; padding-right:1em">         .phys = WINDOW_ADDR,serif; list-style-type:decimal-leading-zero; padding-right:1em"> };
27. /* 默认分区信息*/
28. static struct mtd_partition static_partitions[3] =
29. .name = "bootloader",serif; list-style-type:decimal-leading-zero; padding-right:1em"> .size = 0x40000,//256K
30. .offset = 0
31. },serif; list-style-type:decimal-leading-zero; padding-right:1em"> .name = "Kernel",serif; list-style-type:decimal-leading-zero; padding-right:1em"> .size = 0x100000,//1M
32. .offset = 0x40000
33. .name = "RootFS",serif; list-style-type:decimal-leading-zero; padding-right:1em"> .size = 0xC0000,//768K
34. .offset = 0x140000
35. static const char *probes[] = {NULL};
36. static int mtd_parts_nb = 0;
37. static struct mtd_partition *mtd_parts = 0;
38. /*norflash模型初始化函数
39.  *<1>物理地址映射为虚拟地址: mini2440nor_map.virt = ioremap(WINDOW_ADDR,WINDOW_SIZE);
40.  *<2>探测norflash芯片,得到map_info:do_map_probe();
41.  *<3>探测分区信息,得到mtd_partition：parse_mtd_partitions();
42.  *<4>利用map_info和mtd_partition注册设备:mtd_device_register();
43. int __init init_mini2440nor(void)
44.         static const char *rom_probe_types[] = PROBETYPES;
45.         const char **type;
46.         const char *part_type = 0;
47.         printk(KERN_NOTICE MSG_PREFIX "0x%08x at 0x%08x\n",WINDOW_SIZE,WINDOW_ADDR);
48.         /*物理地址映射为虚拟地址*/
49.         mini2440nor_map.virt = ioremap(WINDOW_ADDR,serif; list-style-type:decimal-leading-zero; padding-right:1em">         if (!mini2440nor_map.virt)
50.         {
51.                 printk(MSG_PREFIX "Failed to ioremap\n");
52.                 return  -EIO;
53.         }
54.         simple_map_init(&mini2440nor_map);
55.         mymtd = 0;
56.         type = rom_probe_types;
57.         for (; !mymtd &&  *type; type++)
58.                 /*根据map_info探测norflash芯片，若成功则返回mtd_info*/
59.                 mymtd = do_map_probe(*type,&mini2440nor_map);
60.         if (mymtd)
61.                 mymtd->owner = THIS_MODULE;
62.                 /*探测分区信息，若探测成功，则mtd_parts中保存了分区信息；若探测失败，使用数组定义的默认分区信息*/
63.                 mtd_parts_nb = parse_mtd_partitions(mymtd,probes,&mtd_parts,MTDID);
64.                 if (mtd_parts_nb > 0)
65.                         part_type = "detected";
66.                 if (mtd_parts_nb == 0)
67.                 {
68.                         mtd_parts = static_partitions;
69.                         mtd_parts_nb = ARRAY_SIZE(static_partitions);
70.                         part_type = "static";
71.                 }
72.                         printk(KERN_NOTICE MSG_PREFIX "no partition info available\n");
73.                 else
74.                         printk(KERN_NOTICE MSG_PREFIX "using %s partition deFinition\n",serif; list-style-type:decimal-leading-zero; padding-right:1em">                                part_type);
75.                 /*注册设备*/
76.                 mtd_device_register(mymtd,NULL,0);
77.                 return 0;
78.         IoUnmap((void *)mini2440nor_map.virt);
79.         return -ENXIO;
80. }
81. /*norflash模块卸载函数
82.  *<1>注销设备:mtd_device_unregister();
83.  *<2>销毁map_info:map_destroy();
84.  *<3>取消映射:IoUnmap();
85. static void __exit cleanup_mini2440nor(void)
86.                 /*注销设备*/
87.                 mtd_device_unregister(mymtd);
88.                 /*销毁map_info*/
89.                 map_destroy(mymtd);
90.         if (mini2440nor_map.virt)
91.                 IoUnmap((void*)mini2440nor_map.virt);
92.                 mini2440nor_map.virt = 0;
93. module_init(init_mini2440nor);
94. module_exit(cleanup_mini2440nor);
96. MODULE_LICENSE("GPL");
97. MODULE_AUTHOR("WeiDong Wu <[e-mail]>");
98. MODULE_DESCRIPTION("Generic configurable MTD map driver");