JZ2440笔记：Nor FLASH驱动程序

(1)测试原有的驱动：

make menuconfig修改physmap-flash驱动配置：起始0，大小0x100000，位宽2，make modules后拷贝过去测试：

# insmod physmap.ko
physmap platform flash device: 01000000 at 00000000
physmap-flash.0: Found 1 x16 devices at 0x0 in 16-bit bank
 Amd/Fujitsu Extended Query Table at 0x0040
number of CFI chips: 1
cfi_cmdset_0002: Disabling erase-suspend-program due to code brokenness.
cmdlinepart partition parsing not available
RedBoot partition parsing not available
# ls /dev/mtd*
/dev/mtd0       /dev/mtd0ro     /dev/mtdblock0
# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00200000 00010000 "physmap-flash.0"

# rmmod physmap.ko
Device 'physmap-flash.0' does not have a release() function, it is broken and must be fixed.
WARNING: at drivers/base/core.c:107 device_release()
不管它

（2）vi s3c_nor.c

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/physmap.h>
#include <asm/io.h>


static struct map_info *s3c_nor_map;
static struct mtd_info *s3c_nor_mtd;

static int s3c_nor_init(void)
{
	s3c_nor_map = kzalloc(sizeof(struct map_info), GFP_KERNEL);

	s3c_nor_map->name = "s3c_nor";
	s3c_nor_map->phys = 0;
	s3c_nor_map->size = 0x1000000;
	s3c_nor_map->bankwidth = 2;
	s3c_nor_map->virt = ioremap(s3c_nor_map->phys, s3c_nor_map->size);
	simple_map_init(s3c_nor_map);

	printk("use cfi_probe\n");
	s3c_nor_mtd = do_map_probe("cfi_probe", s3c_nor_map);
	if(!s3c_nor_mtd)
	{
		printk("use jedec_probe\n");
		s3c_nor_mtd = do_map_probe("jedec_probe", s3c_nor_map);
	}
	if(!s3c_nor_mtd)
	{
		iounmap(s3c_nor_map->virt);
		kfree(s3c_nor_map);
		return -EIO;
	}
	
	return 0;
}

static void s3c_nor_exit(void)
{
	iounmap(s3c_nor_map->virt);
	kfree(s3c_nor_map);
}


module_init(s3c_nor_init);
module_exit(s3c_nor_exit);
MODULE_LICENSE("GPL");

测试驱动：

# insmod s3c_nor.ko
use cfi_probe
s3c_nor: Found 1 x16 devices at 0x0 in 16-bit bank
 Amd/Fujitsu Extended Query Table at 0x0040
number of CFI chips: 1
cfi_cmdset_0002: Disabling erase-suspend-program due to code brokenness.
 

（3）vi s3c_nor.c（添加分区）

static struct map_info *s3c_nor_map;
static struct mtd_info *s3c_nor_mtd;

static struct mtd_partition s3c_nor_parts[] = {
	[0] = {
        .name   = "bootloader_nor",
        .size   = 0x00040000,
		.offset	= 0,
	},
	[1] = {
        .name   = "root_nor",
        .offset = MTDPART_OFS_APPEND,
        .size   = MTDPART_SIZ_FULL,
	}
};


static int s3c_nor_init(void)
{
	s3c_nor_map = kzalloc(sizeof(struct map_info), GFP_KERNEL);

	s3c_nor_map->name = "s3c_nor";
	s3c_nor_map->phys = 0;
	s3c_nor_map->size = 0x1000000;
	s3c_nor_map->bankwidth = 2;
	s3c_nor_map->virt = ioremap(s3c_nor_map->phys, s3c_nor_map->size);
	simple_map_init(s3c_nor_map);

	printk("use cfi_probe\n");
	s3c_nor_mtd = do_map_probe("cfi_probe", s3c_nor_map);
	if(!s3c_nor_mtd)
	{
		printk("use jedec_probe\n");
		s3c_nor_mtd = do_map_probe("jedec_probe", s3c_nor_map);
	}
	if(!s3c_nor_mtd)
	{
		iounmap(s3c_nor_map->virt);
		kfree(s3c_nor_map);
		return -EIO;
	}

	add_mtd_partitions(s3c_nor_map, s3c_nor_parts, 2);
	
	return 0;
}

static void s3c_nor_exit(void)
{
	del_mtd_partitions(s3c_nor_map);
	iounmap(s3c_nor_map->virt);
	kfree(s3c_nor_map);
}

测试驱动：

# insmod s3c_nor.ko
use cfi_probe
s3c_nor: Found 1 x16 devices at 0x0 in 16-bit bank
 Amd/Fujitsu Extended Query Table at 0x0040
number of CFI chips: 1
cfi_cmdset_0002: Disabling erase-suspend-program due to code brokenness.
Creating 2 MTD partitions on "s3c_nor":
0x00000000-0x00040000 : "bootloader_nor"
0x00040000-0x00200000 : "root_nor"
# ls /dev/mtd*
/dev/mtd0       /dev/mtd1       /dev/mtdblock0
/dev/mtd0ro     /dev/mtd1ro     /dev/mtdblock1
Linux系统中/dev/mtd与/dev/mtdblock的区别 - hnrainll - 博客园 (cnblogs.com)

可以继续格式化、挂接、建立文件！