s3c44b0_29f160.c

s3c44b0 NOR FLASH AM29F160 JFFS2文件系统 mtd驱动源代码

/*
 * Flash memory access on SKQ board
 *
 * Liu Tao <[e-mail]>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/config.h>
#include <linux/fs.h>
/*(１) 定义29LF１６０在系统中的起始地址、大小、总线宽度*/
#define WINDOW_ADDR	(0X2000000)
#define WINDOW_SIZE	(0x00200000)
#define BUSWIDTH	2

static struct mtd_info *mymtd;

__u8 s3c44b0_read8(struct map_info *map, unsigned long ofs)
{
	return __raw_readb(map->map_priv_1 + ofs);
}

__u16 s3c44b0_read16(struct map_info *map, unsigned long ofs)
{
	return __raw_readw(map->map_priv_1 + ofs);
}

__u32 s3c44b0_read32(struct map_info *map, unsigned long ofs)
{
	return __raw_readl(map->map_priv_1 + ofs);
}

void s3c44b0_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
{
	memcpy(to, (void *)(map->map_priv_1 + from), len);
}

void s3c44b0_write8(struct map_info *map, __u8 d, unsigned long adr)
{
	__raw_writeb(d, map->map_priv_1 + adr);
	mb();
}

void s3c44b0_write16(struct map_info *map, __u16 d, unsigned long adr)
{
	__raw_writew(d, map->map_priv_1 + adr);
	mb();
}

void s3c44b0_write32(struct map_info *map, __u32 d, unsigned long adr)
{
	__raw_writel(d, map->map_priv_1 + adr);
	mb();
}

void s3c44b0_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
	memcpy((void *)(map->map_priv_1 + to), from, len);
}

struct map_info s3c44b0_map = {
	name: "s3c44b0 flash device",
	size: WINDOW_SIZE,
	buswidth: BUSWIDTH,
	read8: s3c44b0_read8,
	read16: s3c44b0_read16,
	read32: s3c44b0_read32,
	copy_from: s3c44b0_copy_from,
	write8: s3c44b0_write8,
	write16: s3c44b0_write16,
	write32: s3c44b0_write32,
	copy_to: s3c44b0_copy_to
};

/*
 * MTD 'PARTITIONING' STUFF 
 */
/*
(２) 定义ＳＳＴ３９ＶＦ１６０分区
典型的内存分区应包括：内核引导区、Ｌｉｎｕｘ内核区、应用区。其中内核引导区用来保存内核加载程序，
Ｌｉｎｕｘ内核区存放的是经过压缩的ｕＣｌｉｎｕｘ内核，应用区则用来保存用户的数据和应用程序，
该区设为我们要采用的ＪＦＦＳ２文件系统。
*/
static struct mtd_partition s3c44b0_partitions[] = {
        {
                name:  "ｊｆｆｓ２ (2048Ｋ)",
                size: 0x1e0000,
                offset: 0x020000
        }
};

static struct mtd_info *get_mtd_named(char *name)
{
	int i;
	struct mtd_info *mtd;

	for (i = 0; i < MAX_MTD_DEVICES; i++) {
		mtd = get_mtd_device(NULL, i);
		if (mtd) {
			if (strcmp(mtd->name, name) == 0)
				return(mtd);
			put_mtd_device(mtd);
		}
	}
	return(NULL);
}

int __init init_s3c44b0(void)
{
	struct mtd_info *mtd;
	int res;

       	printk(KERN_NOTICE "s3c44b0 flash device: %x at %x\n", WINDOW_SIZE, WINDOW_ADDR);
	s3c44b0_map.map_priv_1 = (unsigned long)ioremap(WINDOW_ADDR, WINDOW_SIZE);

	if (!s3c44b0_map.map_priv_1) {
		printk("Failed to ioremap\n");
		return -EIO;
	}
	mymtd = do_map_probe("jedec_probe", &s3c44b0_map);
	if (mymtd) {
		mymtd->module = THIS_MODULE;
		res = add_mtd_partitions(mymtd, s3c44b0_partitions,
					  sizeof(s3c44b0_partitions) /
					  sizeof(struct mtd_partition));

		mtd = get_mtd_named("rootfs");
		if (mtd) {
			ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
			put_mtd_device(mtd);
		}

		return res;
	}

	iounmap((void *)s3c44b0_map.map_priv_1);
	return -ENXIO;
}

static void __exit cleanup_s3c44b0(void)
{
	if (mymtd) {
		del_mtd_partitions(mymtd);
		map_destroy(mymtd);
	}
	if (s3c44b0_map.map_priv_1) {
		iounmap((void *)s3c44b0_map.map_priv_1);
		s3c44b0_map.map_priv_1 = 0;
	}
}

module_init(init_s3c44b0);
module_exit(cleanup_s3c44b0);