mtdpart.c

基于linux-2.6.28的mtd驱动

/*
 * Simple MTD partitioning layer
 *
 * (C) 2000 Nicolas Pitre <[e-mail]>
 *
 * This code is GPL
 *
 * 	02-21-2002	Thomas Gleixner <[e-mail]>
 *			added support for read_oob, write_oob
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kmod.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/compatmac.h>

/* Our partition linked list */
static LIST_HEAD(mtd_partitions);

/* Our partition node structure */
struct mtd_part {
	struct mtd_info mtd;
	struct mtd_info *master;
	u_int32_t offset;
	int index;
	struct list_head list;
	int registered;
};

/*
 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
 * the pointer to that structure with this macro.
 */
#define PART(x)  ((struct mtd_part *)(x))


/*
 * MTD methods which simply translate the effective address and pass through
 * to the _real_ device.
 */

static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	int res;

	if (from >= mtd->size)
		len = 0;
	else if (from + len > mtd->size)
		len = mtd->size - from;
	res = part->master->read(part->master, from + part->offset,
				   len, retlen, buf);
	if (unlikely(res)) {
		if (res == -EUCLEAN)
			mtd->ecc_stats.corrected++;
		if (res == -EBADMSG)
			mtd->ecc_stats.failed++;
	}
	return res;
}

static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, void **virt, resource_size_t *phys)
{
	struct mtd_part *part = PART(mtd);
	if (from >= mtd->size)
		len = 0;
	else if (from + len > mtd->size)
		len = mtd->size - from;
	return part->master->point (part->master, from + part->offset,
				    len, retlen, virt, phys);
}

static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
	struct mtd_part *part = PART(mtd);

	part->master->unpoint(part->master, from + part->offset, len);
}

static int part_read_oob(struct mtd_info *mtd, loff_t from,
		struct mtd_oob_ops *ops)
{
	struct mtd_part *part = PART(mtd);
	int res;

	if (from >= mtd->size)
		return -EINVAL;
	if (ops->datbuf && from + ops->len > mtd->size)
		return -EINVAL;
	res = part->master->read_oob(part->master, from + part->offset, ops);

	if (unlikely(res)) {
		if (res == -EUCLEAN)
			mtd->ecc_stats.corrected++;
		if (res == -EBADMSG)
			mtd->ecc_stats.failed++;
	}
	return res;
}

static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len, size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->read_user_prot_reg(part->master, from,
					len, retlen, buf);
}

static int part_get_user_prot_info(struct mtd_info *mtd,
		struct otp_info *buf, size_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->get_user_prot_info(part->master, buf, len);
}

static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len, size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->read_fact_prot_reg(part->master, from,
					len, retlen, buf);
}

static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
		size_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->get_fact_prot_info(part->master, buf, len);
}

static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
	if (to >= mtd->size)
		len = 0;
	else if (to + len > mtd->size)
		len = mtd->size - to;
	return part->master->write(part->master, to + part->offset,
				    len, retlen, buf);
}

static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
	if (to >= mtd->size)
		len = 0;
	else if (to + len > mtd->size)
		len = mtd->size - to;
	return part->master->panic_write(part->master, to + part->offset,
				    len, retlen, buf);
}

static int part_write_oob(struct mtd_info *mtd, loff_t to,
		struct mtd_oob_ops *ops)
{
	struct mtd_part *part = PART(mtd);

	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;

	if (to >= mtd->size)
		return -EINVAL;
	if (ops->datbuf && to + ops->len > mtd->size)
		return -EINVAL;
	return part->master->write_oob(part->master, to + part->offset, ops);
}

static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len, size_t *retlen, u_char *buf)
{
	struct mtd_part *part = PART(mtd);
	return part->master->write_user_prot_reg(part->master, from,
					len, retlen, buf);
}

static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
		size_t len)
{
	struct mtd_part *part = PART(mtd);
	return part->master->lock_user_prot_reg(part->master, from, len);
}

static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
		unsigned long count, loff_t to, size_t *retlen)
{
	struct mtd_part *part = PART(mtd);
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
	return part->master->writev(part->master, vecs, count,
					to + part->offset, retlen);
}

static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	struct mtd_part *part = PART(mtd);
	int ret;
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
	if (instr->addr >= mtd->size)
		return -EINVAL;
	instr->addr += part->offset;
	ret = part->master->erase(part->master, instr);
	if (ret) {
		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
			instr->fail_addr -= part->offset;
		instr->addr -= part->offset;
	}
	return ret;
}

void mtd_erase_callback(struct erase_info *instr)
{
	if (instr->mtd->erase == part_erase) {
		struct mtd_part *part = PART(instr->mtd);

		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
			instr->fail_addr -= part->offset;
		instr->addr -= part->offset;
	}
	if (instr->callback)
		instr->callback(instr);
}
EXPORT_SYMBOL_GPL(mtd_erase_callback);

static int part_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
{
	struct mtd_part *part = PART(mtd);
	if ((len + ofs) > mtd->size)
		return -EINVAL;
	return part->master->lock(part->master, ofs + part->offset, len);
}

static int part_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
{
	struct mtd_part *part = PART(mtd);
	if ((len + ofs) > mtd->size)
		return -EINVAL;
	return part->master->unlock(part->master, ofs + part->offset, len);
}

static void part_sync(struct mtd_info *mtd)
{
	struct mtd_part *part = PART(mtd);
	part->master->sync(part->master);
}

static int part_suspend(struct mtd_info *mtd)
{
	struct mtd_part *part = PART(mtd);
	return part->master->suspend(part->master);
}

static void part_resume(struct mtd_info *mtd)
{
	struct mtd_part *part = PART(mtd);
	part->master->resume(part->master);
}

static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
	struct mtd_part *part = PART(mtd);
	if (ofs >= mtd->size)
		return -EINVAL;
	ofs += part->offset;
	return part->master->block_isbad(part->master, ofs);
}

static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
	struct mtd_part *part = PART(mtd);
	int res;

	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
	if (ofs >= mtd->size)
		return -EINVAL;
	ofs += part->offset;
	res = part->master->block_markbad(part->master, ofs);
	if (!res)