分类： LINUX
2009-03-23 21:53:25
arm-linux东东nand:前记.
由于刚开始写blog.且本人也只不过是在校的一个学生.难免出错.如果错了请告诉我一下,谢谢
一,nand 初始化:
环境:linux2.6.26,S3C2440
在LINUX中NAND驱动是在DRIVERS/MTD目录中.
Makefile指示 nand 是构架在MTD之上的.
而MTD有字驱动,块驱动之分,还有一个是分区.而NAND是块驱动.多数的NAND是512为一个寻址单位.以32个512为一个block.这是从Makefile开始
obj-$(CONFIG_MTD) += mtd.o
mtd-y := mtdcore.o mtdsuper.o
mtd-$(CONFIG_MTD_PARTITIONS) += mtdpart.o
obj-$(CONFIG_MTD_CONCAT) += mtdconcat.o
obj-$(CONFIG_MTD_REDBOOT_PARTS) += redboot.o
obj-$(CONFIG_MTD_CMDLINE_PARTS) += cmdlinepart.o
obj-$(CONFIG_MTD_AFS_PARTS) += afs.o
obj-$(CONFIG_MTD_AR7_PARTS) += ar7part.o
obj-$(CONFIG_MTD_OF_PARTS) += ofpart.o
# 'Users' - code which presents functionality to userspace.
obj-$(CONFIG_MTD_CHAR) += mtdchar.o
obj-$(CONFIG_MTD_BLKDEVS) += mtd_blkdevs.o
obj-$(CONFIG_MTD_BLOCK) += mtdblock.o
obj-$(CONFIG_MTD_BLOCK_RO) += mtdblock_ro.o
obj-$(CONFIG_FTL) += ftl.o
obj-$(CONFIG_NFTL) += nftl.o
obj-$(CONFIG_INFTL) += inftl.o
obj-$(CONFIG_RFD_FTL) += rfd_ftl.o
obj-$(CONFIG_SSFDC) += ssfdc.o
obj-$(CONFIG_MTD_OOPS) += mtdoops.o
nftl-objs := nftlcore.o nftlmount.o
inftl-objs := inftlcore.o inftlmount.o
obj-y += chips/ maps/ devices/ nand/ onenand/
obj-$(CONFIG_MTD_UBI) += ubi/
看到没有如果定义了CONFIG_MTD_PARTITIONS就说明支持分区.我们所要看的目录以及文件就是mtd.o, mtdpart.o mtd_blkdevs.o
而首先看的是devices 目录下的s3c2410.c这个文件.
module_init(s3c2410_nand_init);
module_exit(s3c2410_nand_exit);
于是从s3c2410_nand_init开始
static int __i static struct platform_driver s3c2440_nand_driver = {
.probe = s3c2440_nand_probe,
.remove = s3c2410_nand_remove,
.suspend = s3c24xx_nand_suspend,
.resume = s3c24xx_nand_resume,
.driver = {
.name = "s3c2440-nand",
.owner = THIS_MODULE,
},
};
nit s3c2410_nand_init(void)
{
printk("S3C24XX NAND Driver, (c) 2004 Simtec Electronics\n");
platform_driver_register(&s3c2412_nand_driver);
platform_driver_register(&s3c2440_nand_driver);
return platform_driver_register(&s3c2410_nand_driver);
}
很简单.就是打印一些东西.然后调用platform_driver_register.
所有platform的构架都会调用.probe.但是有一个条件:就是s3c2440_nand_driver遇到了属于它自已的设备.
在很久很久以前设备已经被注册进去了.只是我们的眼睛没有觉察到而已.
在linux-2.6.26\arch\arm\plat-s3c24xx\common-smdk.c
static struct mtd_partition smdk_default_nand_part[] = {
[0] = {
.name = "Boot Agent",
.size = SZ_16K,
.offset = 0,
},
[1] = {
.name = "S3C2410 flash partition 1",
.offset = 0,
.size = SZ_2M,
},
[2] = {
.name = "S3C2410 flash partition 2",
.offset = SZ_4M,
.size = SZ_4M,
},
[3] = {
.name = "S3C2410 flash partition 3",
.offset = SZ_8M,
.size = SZ_2M,
},
[4] = {
.name = "S3C2410 flash partition 4",
.offset = SZ_1M * 10,
.size = SZ_4M,
},
[5] = {
.name = "S3C2410 flash partition 5",
.offset = SZ_1M * 14,
.size = SZ_1M * 10,
},
[6] = {
.name = "S3C2410 flash partition 6",
.offset = SZ_1M * 24,
.size = SZ_1M * 24,
},
[7] = {
.name = "S3C2410 flash partition 7",
.offset = SZ_1M * 48,
.size = SZ_16M,
}
};
static struct s3c2410_nand_set smdk_nand_sets[] = {
[0] = {
.name = "NAND",
.nr_chips = 1,
.nr_partitions = ARRAY_SIZE(smdk_default_nand_part),
.partitions = smdk_default_nand_part,
},
};
/* choose a set of timings which should suit most 512Mbit
* chips and beyond.
*/
static struct s3c2410_platform_nand smdk_nand_info = {
.tacls = 20,
.twrph0 = 60,
.twrph1 = 20,
.nr_sets = ARRAY_SIZE(smdk_nand_sets),
.sets = smdk_nand_sets,
};
/* devices we initialise */
static struct platform_device __initdata *smdk_devs[] = {
&s3c_device_nand,
&smdk_led4,
&smdk_led5,
&smdk_led6,
&smdk_led7,
};
platform_add_devices(smdk_devs, ARRAY_SIZE(smdk_devs));
看到没有s3c_device_nand.这就是设备.没有错.
这里有几个结构体: smdk_default_nand_part表示分区.移植的同志们对这个是很敏感的.
smdk_nand_sets表示有几块NAND.
请记着有这么些东西.因为在后面我们会回来.
