NOR Flash Driver

Drivers

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 Allocate map_info structure*/ 45 nor_map = kmalloc( sizeof ( struct map_info), GFP_KERNEL); 46 /******** 2 end ********/ 47 48 49 /* 3 Settings: physical base address (phys), size (size), bankwidth, virtual base address (virt) */ 50 nor_map -> name = "nor" ; 51 nor_map -> phys = 0 ; 52 nor_map -> size = 1000000 ; //16M, larger than the actual size of nor 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 Use: call the function provided by the Nor Flash protocol layer to identify*/ 61 printk( "use cfi_probe n " ); 62 nor_mtd = do_map_probe( "cfi_probe " , nor_map); 63 if ( ! nor_mtd) 64 { 65 printk( "use jedec_probe n " ); 66 nor_mtd = do_map_probe( "jedec_probe" , nor_map); 67 } 68 69 if ( ! nor_mtd) 70 { 71 printk( "fail n " ); 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 ********/

debug

Test 1: Configure the kernel to support 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 // Physical base address

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

(2) Bank width in octets (NEW) // bit width

2. make modules

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

3. Start the development board

ls /dev/mtd*

insmod physmap.ko

ls /dev/mtd*

cat /proc/mtd

Test 2: Using a self-written driver:

1. ls /dev/mtd*

2. insmod s3c_nor.ko

3. ls /dev/mtd*

4. Format: flash_eraseall -j /dev/mtd1

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

Operate files in the /mnt directory

NOR FLASH identification process:

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

// Enter CFI mode

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

// See if "QRY" can be read

qry_present(map,base,cfi)

.....

do_map_probe("jedec_probe", s3c_nor_map);

drv = get_mtd_chip_driver(name)

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

eater_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

// Unlock

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);

// Read ID command

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

// Get the manufacturer ID and device ID

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

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

// Compare with array

jedec_table