nand_base.c

老版本的mtd-snap

/*
 *  drivers/mtd/nand.c
 *
 *  Overview:
 *   This is the generic MTD driver for NAND flash devices. It should be
 *   capable of working with almost all NAND chips currently available.
 *   Basic support for AG-AND chips is provided.
 *   
 *	Additional technical information is available on
 *	http://www.linux-mtd.infradead.org/tech/nand.html
 *	
 *  Copyright (C) 2000 Steven J. Hill ([e-mail])
 * 		  2002 Thomas Gleixner ([e-mail])
 *
 *  02-08-2004  tglx: support for strange chips, which cannot auto increment 
 *		pages on read / read_oob
 *
 *  03-17-2004  tglx: Check ready before auto increment check. Simon Bayes
 *		pointed this out, as he marked an auto increment capable chip
 *		as NOAUTOINCR in the board driver.
 *		Make reads over block boundaries work too
 *
 *  04-14-2004	tglx: first working version for 2k page size chips
 *  
 *  05-19-2004  tglx: Basic support for Renesas AG-AND chips
 *
 *  09-24-2004  tglx: add support for hardware controllers (e.g. ECC) shared
 *		among multiple independend devices. Suggestions and initial patch
 *		from Ben Dooks <[e-mail]>
 *
 *  12-05-2004	dmarlin: add workaround for Renesas AG-AND chips "disturb" issue.
 *		Basically, any block not rewritten may lose data when surrounding blocks
 *		are rewritten many times.  JFFS2 ensures this doesn't happen for blocks 
 *		it uses, but the Bad Block Table(s) may not be rewritten.  To ensure they
 *		do not lose data, force them to be rewritten when some of the surrounding
 *		blocks are erased.  Rather than tracking a specific nearby block (which 
 *		could itself go bad), use a page address 'mask' to select several blocks 
 *		in the same area, and rewrite the BBT when any of them are erased.
 *
 *  01-03-2005	dmarlin: added support for the device recovery command sequence for Renesas 
 *		AG-AND chips.  If there was a sudden loss of power during an erase operation,
 * 		a "device recovery" operation must be performed when power is restored
 * 		to ensure correct operation.
 *
 *  01-20-2005	dmarlin: added support for optional hardware specific callback routine to 
 *		perform extra error status checks on erase and write failures.  This required
 *		adding a wrapper function for nand_read_ecc.
 *
 * Credits:
 *	David Woodhouse for adding multichip support  
 *	
 *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
 *	rework for 2K page size chips
 *
 * TODO:
 *	Enable cached programming for 2k page size chips
 *	Check, if mtd->ecctype should be set to MTD_ECC_HW
 *	if we have HW ecc support.
 *	The AG-AND chips have nice features for speed improvement,
 *	which are not supported yet. Read / program 4 pages in one go.
 *
 * $Id: nand_base.c,v 1.147 2005/07/15 07:18:06 gleixner Exp $
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/compatmac.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <asm/io.h>

#ifdef CONFIG_MTD_PARTITIONS
#include <linux/mtd/partitions.h>
#endif

/* Define default oob placement schemes for large and small page devices */
static struct nand_oobinfo nand_oob_8 = {
	.useecc = MTD_NANDECC_AUTOPLACE,
	.eccbytes = 3,
	.eccpos = {0, 1, 2},
	.oobfree = { {3, 2}, {6, 2} }
};

static struct nand_oobinfo nand_oob_16 = {
	.useecc = MTD_NANDECC_AUTOPLACE,
	.eccbytes = 6,
	.eccpos = {0, 1, 2, 3, 6, 7},
	.oobfree = { {8, 8} }
};

static struct nand_oobinfo nand_oob_64 = {
	.useecc = MTD_NANDECC_AUTOPLACE,
	.eccbytes = 24,
	.eccpos = {
		40, 41, 42, 43, 44, 45, 46, 47, 
		48, 49, 50, 51, 52, 53, 54, 55, 
		56, 57, 58, 59, 60, 61, 62, 63},
	.oobfree = { {2, 38} }
};

/* This is used for padding purposes in nand_write_oob */
static u_char ffchars[] = {
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};

/*
 * NAND low-level MTD interface functions
 */
static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len);
static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len);
static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len);

static int nand_read (struct mtd_info *mtd, loff_t from, size_t len, size_t * retlen, u_char * buf);
static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
			  size_t * retlen, u_char * buf, u_char * eccbuf, struct nand_oobinfo *oobsel);
static int nand_read_oob (struct mtd_info *mtd, loff_t from, size_t len, size_t * retlen, u_char * buf);
static int nand_write (struct mtd_info *mtd, loff_t to, size_t len, size_t * retlen, const u_char * buf);
static int nand_write_ecc (struct mtd_info *mtd, loff_t to, size_t len,
			   size_t * retlen, const u_char * buf, u_char * eccbuf, struct nand_oobinfo *oobsel);
static int nand_write_oob (struct mtd_info *mtd, loff_t to, size_t len, size_t * retlen, const u_char *buf);
static int nand_writev (struct mtd_info *mtd, const struct kvec *vecs,
			unsigned long count, loff_t to, size_t * retlen);
static int nand_writev_ecc (struct mtd_info *mtd, const struct kvec *vecs,
			unsigned long count, loff_t to, size_t * retlen, u_char *eccbuf, struct nand_oobinfo *oobsel);
static int nand_erase (struct mtd_info *mtd, struct erase_info *instr);
static void nand_sync (struct mtd_info *mtd);

/* Some internal functions */
static int nand_write_page (struct mtd_info *mtd, struct nand_chip *this, int page, u_char *oob_buf,
		struct nand_oobinfo *oobsel, int mode);
#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
static int nand_verify_pages (struct mtd_info *mtd, struct nand_chip *this, int page, int numpages, 
	u_char *oob_buf, struct nand_oobinfo *oobsel, int chipnr, int oobmode);
#else
#define nand_verify_pages(...) (0)
#endif
		
static void nand_get_device (struct nand_chip *this, struct mtd_info *mtd, int new_state);

/**
 * nand_release_device - [GENERIC] release chip
 * @mtd:	MTD device structure
 * 
 * Deselect, release chip lock and wake up anyone waiting on the device 
 */
static void nand_release_device (struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;

	/* De-select the NAND device */
	this->select_chip(mtd, -1);

	if (this->controller) {
		/* Release the controller and the chip */
		spin_lock(&this->controller->lock);
		this->controller->active = NULL;
		this->state = FL_READY;
		wake_up(&this->controller->wq);
		spin_unlock(&this->controller->lock);
	} else {
		/* Release the chip */
		spin_lock(&this->chip_lock);
		this->state = FL_READY;
		wake_up(&this->wq);
		spin_unlock(&this->chip_lock);
	}
}

/**
 * nand_read_byte - [DEFAULT] read one byte from the chip
 * @mtd:	MTD device structure
 *
 * Default read function for 8bit buswith
 */
static u_char nand_read_byte(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	return readb(this->IO_ADDR_R);
}

/**
 * nand_write_byte - [DEFAULT] write one byte to the chip
 * @mtd:	MTD device structure
 * @byte:	pointer to data byte to write
 *
 * Default write function for 8it buswith
 */
static void nand_write_byte(struct mtd_info *mtd, u_char byte)
{
	struct nand_chip *this = mtd->priv;
	writeb(byte, this->IO_ADDR_W);
}

/**
 * nand_read_byte16 - [DEFAULT] read one byte endianess aware from the chip
 * @mtd:	MTD device structure
 *
 * Default read function for 16bit buswith with 
 * endianess conversion
 */
static u_char nand_read_byte16(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	return (u_char) cpu_to_le16(readw(this->IO_ADDR_R));
}

/**
 * nand_write_byte16 - [DEFAULT] write one byte endianess aware to the chip
 * @mtd:	MTD device structure
 * @byte:	pointer to data byte to write
 *
 * Default write function for 16bit buswith with
 * endianess conversion
 */
static void nand_write_byte16(struct mtd_info *mtd, u_char byte)
{
	struct nand_chip *this = mtd->priv;
	writew(le16_to_cpu((u16) byte), this->IO_ADDR_W);
}

/**
 * nand_read_word - [DEFAULT] read one word from the chip
 * @mtd:	MTD device structure
 *
 * Default read function for 16bit buswith without 
 * endianess conversion
 */
static u16 nand_read_word(struct mtd_info *mtd)
{
	struct nand_chip *this = mtd->priv;
	return readw(this->IO_ADDR_R);
}

/**
 * nand_write_word - [DEFAULT] write one word to the chip
 * @mtd:	MTD device structure
 * @word:	data word to write
 *
 * Default write function for 16bit buswith without 
 * endianess conversion
 */
static void nand_write_word(struct mtd_info *mtd, u16 word)
{
	struct nand_chip *this = mtd->priv;
	writew(word, this->IO_ADDR_W);
}

/**
 * nand_select_chip - [DEFAULT] control CE line
 * @mtd:	MTD device structure
 * @chip:	chipnumber to select, -1 for deselect
 *
 * Default select function for 1 chip devices.
 */
static void nand_select_chip(struct mtd_info *mtd, int chip)
{
	struct nand_chip *this = mtd->priv;
	switch(chip) {
	case -1:
		this->hwcontrol(mtd, NAND_CTL_CLRNCE);	
		break;
	case 0:
		this->hwcontrol(mtd, NAND_CTL_SETNCE);
		break;

	default:
		BUG();
	}
}

/**
 * nand_write_buf - [DEFAULT] write buffer to chip
 * @mtd:	MTD device structure
 * @buf:	data buffer
 * @len:	number of bytes to write
 *
 * Default write function for 8bit buswith
 */
static void nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;

	for (i=0; i<len; i++)
		writeb(buf[i], this->IO_ADDR_W);
}

/**
 * nand_read_buf - [DEFAULT] read chip data into buffer 
 * @mtd:	MTD device structure
 * @buf:	buffer to store date
 * @len:	number of bytes to read
 *
 * Default read function for 8bit buswith
 */
static void nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;

	for (i=0; i<len; i++)
		buf[i] = readb(this->IO_ADDR_R);
}

/**
 * nand_verify_buf - [DEFAULT] Verify chip data against buffer 
 * @mtd:	MTD device structure
 * @buf:	buffer containing the data to compare
 * @len:	number of bytes to compare
 *
 * Default verify function for 8bit buswith
 */
static int nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;

	for (i=0; i<len; i++)
		if (buf[i] != readb(this->IO_ADDR_R))
			return -EFAULT;

	return 0;
}

/**
 * nand_write_buf16 - [DEFAULT] write buffer to chip
 * @mtd:	MTD device structure
 * @buf:	data buffer
 * @len:	number of bytes to write
 *
 * Default write function for 16bit buswith
 */
static void nand_write_buf16(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	u16 *p = (u16 *) buf;
	len >>= 1;
	
	for (i=0; i<len; i++)
		writew(p[i], this->IO_ADDR_W);
		
}

/**
 * nand_read_buf16 - [DEFAULT] read chip data into buffer 
 * @mtd:	MTD device structure
 * @buf:	buffer to store date
 * @len:	number of bytes to read
 *
 * Default read function for 16bit buswith
 */
static void nand_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	u16 *p = (u16 *) buf;
	len >>= 1;

	for (i=0; i<len; i++)
		p[i] = readw(this->IO_ADDR_R);
}

/**
 * nand_verify_buf16 - [DEFAULT] Verify chip data against buffer 
 * @mtd:	MTD device structure
 * @buf:	buffer containing the data to compare
 * @len:	number of bytes to compare
 *
 * Default verify function for 16bit buswith
 */
static int nand_verify_buf16(struct mtd_info *mtd, const u_char *buf, int len)
{
	int i;
	struct nand_chip *this = mtd->priv;
	u16 *p = (u16 *) buf;
	len >>= 1;

	for (i=0; i<len; i++)
		if (p[i] != readw(this->IO_ADDR_R))
			return -EFAULT;

	return 0;
}

/**
 * nand_block_bad - [DEFAULT] Read bad block marker from the chip
 * @mtd:	MTD device structure
 * @ofs:	offset from device start
 * @getchip:	0, if the chip is already selected
 *
 * Check, if the block is bad. 
 */
static int nand_block_bad(struct mtd_info *mtd, loff_t ofs, int getchip)
{
	int page, chipnr, res = 0;
	struct nand_chip *this = mtd->priv;
	u16 bad;

	if (getchip) {
		page = (int)(ofs >> this->page_shift);
		chipnr = (int)(ofs >> this->chip_shift);

		/* Grab the lock and see if the device is available */
		nand_get_device (this, mtd, FL_READING);

		/* Select the NAND device */
		this->select_chip(mtd, chipnr);
	} else 
		page = (int) ofs;	

	if (this->options & NAND_BUSWIDTH_16) {
		this->cmdfunc (mtd, NAND_CMD_READOOB, this->badblockpos & 0xFE, page & this->pagemask);
		bad = cpu_to_le16(this->read_word(mtd));
		if (this->badblockpos & 0x1)
			bad >>= 1;
		if ((bad & 0xFF) != 0xff)
			res = 1;
	} else {
		this->cmdfunc (mtd, NAND_CMD_READOOB, this->badblockpos, page & this->pagemask);
		if (this->read_byte(mtd) != 0xff)
			res = 1;