yynf_nand.c

nand flash驱动

/*
 *  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.
 *   
 *	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])
 *
 *  10-29-2001  Thomas Gleixner ([e-mail])
 * 		- Changed nand_chip structure for controlline function to
 *		support different hardware structures (Access to
 *		controllines ALE,CLE,NCE via hardware specific function. 
 *		- exit out of "failed erase block" changed, to avoid
 *		driver hangup
 *		- init_waitqueue_head added in function nand_scan !!
 *
 *  01-30-2002  Thomas Gleixner ([e-mail])
 *		change in nand_writev to block invalid vecs entries
 *
 *  02-11-2002  Thomas Gleixner ([e-mail])
 *		- major rewrite to avoid duplicated code
 *		  common nand_write_page function  
 *		  common get_chip function 
 *		- added oob_config structure for out of band layouts
 *		- write_oob changed for partial programming
 *		- read cache for faster access for subsequent reads
 *		from the same page.
 *		- support for different read/write address
 *		- support for device ready/busy line
 *		- read oob for more than one page enabled
 *
 *  02-27-2002	Thomas Gleixner ([e-mail])
 *		- command-delay can be programmed
 *		- fixed exit from erase with callback-function enabled
 *
 *  03-21-2002  Thomas Gleixner ([e-mail])
 *		- DEBUG improvements provided by Elizabeth Clarke 
 *		([e-mail])
 *		- added zero check for this->chip_delay
 *
 *  04-03-2002  Thomas Gleixner ([e-mail])
 *		- added added hw-driver supplied command and wait functions
 *		- changed blocking for erase (erase suspend enabled)
 *		- check pointers before accessing flash provided by
 *		John Hall ([e-mail])
 *
 *  04-09-2002  Thomas Gleixner ([e-mail])
 *		- nand_wait repaired
 *
 *  04-28-2002  Thomas Gleixner ([e-mail])	
 *		- OOB config defines moved to nand.h 
 *
 *  08-01-2002  Thomas Gleixner ([e-mail])	
 *		- changed my mailaddress, added pointer to tech/nand.html
 *
 *  08-07-2002 	Thomas Gleixner ([e-mail])
 *		forced bad block location to byte 5 of OOB, even if
 *		CONFIG_MTD_NAND_ECC_JFFS2 is not set, to prevent
 *		erase /dev/mtdX from erasing bad blocks and destroying
 *		bad block info
 *
 *  08-10-2002 	Thomas Gleixner ([e-mail])
 *		Fixed writing tail of data. Thanks to Alice Hennessy
 *		<[e-mail]>.
 *
 *  08-10-2002 	Thomas Gleixner ([e-mail])
 *		nand_read_ecc and nand_write_page restructured to support
 *		hardware ECC. Thanks to Steven Hein ([e-mail])
 *		for basic implementation and suggestions.
 *		3 new pointers in nand_chip structure:
 *		calculate_ecc, correct_data, enabled_hwecc 					 
 *		forcing all hw-drivers to support page cache
 *		eccvalid_pos is now mandatory
 *
 *  08-17-2002	tglx: fixed signed/unsigned missmatch in write.c
 *		Thanks to Ken Offer <[e-mail]> 	
 *
 *  08-29-2002  tglx: use buffered read/write only for non pagealigned 
 *		access, speed up the aligned path by using the fs-buffer
 *		reset chip removed from nand_select(), implicit done
 *		only, when erase is interrupted
 *		waitfuntion use yield, instead of schedule_timeout
 *		support for 6byte/512byte hardware ECC
 *		read_ecc, write_ecc extended for different oob-layout
 *		selections: Implemented NAND_NONE_OOB, NAND_JFFS2_OOB,
 *		NAND_YAFFS_OOB. fs-driver gives one of these constants
 *		to select the oob-layout fitting the filesystem.
 *		oobdata can be read together with the raw data, when
 *		the fs-driver supplies a big enough buffer.
 *		size = 12 * number of pages to read (256B pagesize)
 *		       24 * number of pages to read (512B pagesize)
 *		the buffer contains 8/16 byte oobdata and 4/8 byte
 *		returncode from calculate_ecc
 *		oobdata can be given from filesystem to program them
 *		in one go together with the raw data. ECC codes are
 *		filled in at the place selected by oobsel.
 *
 *  09-04-2002  tglx: fixed write_verify (John Hall ([e-mail]))
 *
 *  11-11-2002  tglx: fixed debug output in nand_write_page 
 *		(John Hall ([e-mail]))
 *
 *  11-25-2002  tglx: Moved device ID/ manufacturer ID from nand_ids.h
 *		Splitted device ID and manufacturer ID table. 
 *		Removed CONFIG_MTD_NAND_ECC, as it defaults to ECC_NONE for
 *		mtd->read / mtd->write and is controllable by the fs driver
 *		for mtd->read_ecc / mtd->write_ecc
 *		some minor cleanups
 *
 *  12-05-2000  tglx: Dave Ellis (DGE@sixnetio) provided the fix for
 *		WRITE_VERIFY long time ago. Thanks for remembering me.	
 *	
 * $Id: nand.c,v 1.36 2002/12/05 20:59:11 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/types.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nand_ecc.h>
#include <linux/mtd/partitions.h>
#include <linux/interrupt.h>
#include <asm/io.h>

/*
 * Macros for low-level register control
 */
#define nand_select()	this->hwcontrol(NAND_CTL_SETNCE);

#define nand_deselect() this->hwcontrol(NAND_CTL_CLRNCE);

/*
 * out of band configuration for different filesystems
 */
static int oobconfigs[][6] = {
	{ 0,0,0,0,0,0},

	{ NAND_JFFS2_OOB_ECCPOS0, NAND_JFFS2_OOB_ECCPOS1, NAND_JFFS2_OOB_ECCPOS2,
	NAND_JFFS2_OOB_ECCPOS3, NAND_JFFS2_OOB_ECCPOS4, NAND_JFFS2_OOB_ECCPOS5 },

	{ NAND_YAFFS_OOB_ECCPOS0, NAND_YAFFS_OOB_ECCPOS1, NAND_YAFFS_OOB_ECCPOS2,
	NAND_YAFFS_OOB_ECCPOS3, NAND_YAFFS_OOB_ECCPOS4, NAND_YAFFS_OOB_ECCPOS5 }	
};

/*
 * NAND low-level MTD interface functions
 */
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, int 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, int 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 iovec *vecs,
			unsigned long count, loff_t to, size_t * retlen);
static int nand_writev_ecc (struct mtd_info *mtd, const struct iovec *vecs,
			unsigned long count, loff_t to, size_t * retlen, u_char *eccbuf, int oobsel);
static int nand_erase (struct mtd_info *mtd, struct erase_info *instr);
static void nand_sync (struct mtd_info *mtd);
static int nand_write_page (struct mtd_info *mtd, struct nand_chip *this, int page, int col, 
			int last, u_char *oob_buf, int oobsel);
/*
 * Send command to NAND device
 */
static void nand_command (struct mtd_info *mtd, unsigned command, int column, int page_addr)
{
	register struct nand_chip *this = mtd->priv;
	register unsigned long NAND_IO_ADDR = this->IO_ADDR_W;

	/* Begin command latch cycle */
	this->hwcontrol (NAND_CTL_SETCLE);
	/*
	 * Write out the command to the device.
	 */
	if (command != NAND_CMD_SEQIN)
		writeb (command, NAND_IO_ADDR);
	else {
		if (mtd->oobblock == 256 && column >= 256) {
			column -= 256;
			writeb (NAND_CMD_READOOB, NAND_IO_ADDR);
			writeb (NAND_CMD_SEQIN, NAND_IO_ADDR);
		} else if (mtd->oobblock == 512 && column >= 256) {
			if (column < 512) {
				column -= 256;
				writeb (NAND_CMD_READ1, NAND_IO_ADDR);
				writeb (NAND_CMD_SEQIN, NAND_IO_ADDR);
			} else {
				column -= 512;
				writeb (NAND_CMD_READOOB, NAND_IO_ADDR);
				writeb (NAND_CMD_SEQIN, NAND_IO_ADDR);
			}
		} else {
			writeb (NAND_CMD_READ0, NAND_IO_ADDR);
			writeb (NAND_CMD_SEQIN, NAND_IO_ADDR);
		}
	}

	/* Set ALE and clear CLE to start address cycle */
	this->hwcontrol (NAND_CTL_CLRCLE);

	if (column != -1 || page_addr != -1) {
		this->hwcontrol (NAND_CTL_SETALE);

		/* Serially input address */
		if (column != -1)
			writeb (column, NAND_IO_ADDR);
		if (page_addr != -1) {
			writeb ((unsigned char) (page_addr & 0xff), NAND_IO_ADDR);
			writeb ((unsigned char) ((page_addr >> 8) & 0xff), NAND_IO_ADDR);
			/* One more address cycle for higher density devices */
			if (mtd->size & 0x0c000000) 
				writeb ((unsigned char) ((page_addr >> 16) & 0x0f), NAND_IO_ADDR);
		}
		/* Latch in address */
		this->hwcontrol (NAND_CTL_CLRALE);
	}
	
	/* 
	 * program and erase have their own busy handlers 
	 * status and sequential in needs no delay
	*/
	switch (command) {
			
	case NAND_CMD_PAGEPROG:
	case NAND_CMD_ERASE1:
	case NAND_CMD_ERASE2:
	case NAND_CMD_SEQIN:
	case NAND_CMD_STATUS:
		return;

	case NAND_CMD_RESET:
		if (this->dev_ready)	
			break;
		this->hwcontrol (NAND_CTL_SETCLE);
		writeb (NAND_CMD_STATUS, NAND_IO_ADDR);
		this->hwcontrol (NAND_CTL_CLRCLE);
		while ( !(readb (this->IO_ADDR_R) & 0x40));
		return;

	/* This applies to read commands */	
	default:
		/* 
		 * If we don't have access to the busy pin, we apply the given
		 * command delay
		*/
		if (!this->dev_ready) {
			udelay (this->chip_delay);
			return;
		}	
	}
	
	/* wait until command is processed */
	while (!this->dev_ready());
}

/*
 *	Get chip for selected access
 */
static inline void nand_get_chip (struct nand_chip *this, struct mtd_info *mtd, int new_state, int *erase_state)
{

	DECLARE_WAITQUEUE (wait, current);

	/* 
	 * Grab the lock and see if the device is available 
	 * For erasing, we keep the spinlock until the
	 * erase command is written. 
	*/
retry:
	spin_lock_bh (&this->chip_lock);

	if (this->state == FL_READY) {
		this->state = new_state;
		if (new_state != FL_ERASING)
			spin_unlock_bh (&this->chip_lock);
		return;
	}

	if (this->state == FL_ERASING) {
		if (new_state != FL_ERASING) {
			this->state = new_state;
			spin_unlock_bh (&this->chip_lock);
			nand_select ();	/* select in any case */
			this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
			return;
		}
	}

	set_current_state (TASK_UNINTERRUPTIBLE);
	add_wait_queue (&this->wq, &wait);
	spin_unlock_bh (&this->chip_lock);
	schedule ();
	remove_wait_queue (&this->wq, &wait);
	goto retry;
}

/*
 * Wait for command done. This applies to erase and program only
 * Erase can take up to 400ms and program up to 20ms according to 
 * general NAND and SmartMedia specs
 *
*/
static int nand_wait(struct mtd_info *mtd, struct nand_chip *this, int state)
{

	unsigned long	timeo = jiffies;
	int	status;
	
	if (state == FL_ERASING)
		 timeo += (HZ * 400) / 1000;
	else
		 timeo += (HZ * 20) / 1000;

	spin_lock_bh (&this->chip_lock);
	this->cmdfunc (mtd, NAND_CMD_STATUS, -1, -1);

	while (time_before(jiffies, timeo)) {		
		/* Check, if we were interrupted */
		if (this->state != state) {
			spin_unlock_bh (&this->chip_lock);
			return 0;
		}
		if (this->dev_ready) {
			if (this->dev_ready ())
				break;
		}
		if (readb (this->IO_ADDR_R) & 0x40)
			break;
						
		spin_unlock_bh (&this->chip_lock);
		yield ();
		spin_lock_bh (&this->chip_lock);
	}
	status = (int) readb (this->IO_ADDR_R);
	spin_unlock_bh (&this->chip_lock);

	return status;
}

/*
 *	Nand_page_program function is used for write and writev !
 */
static int nand_write_page (struct mtd_info *mtd, struct nand_chip *this,
			    int page, int col, int last, u_char *oob_buf, int oobsel)
{
	int 	i, status;
	u_char	ecc_code[6], *oob_data;
	int	eccmode = oobsel ? this->eccmode : NAND_ECC_NONE;
	int  	*oob_config = oobconfigs[oobsel];

	/* pad oob area, if we have no oob buffer from fs-driver */
	if (!oob_buf) {
		oob_data = &this->data_buf[mtd->oobblock];
		for (i = 0; i < mtd->oobsize; i++)
			oob_data[i] = 0xff;
	} else 
		oob_data = oob_buf;
	
	/* software ecc 3 Bytes ECC / 256 Byte Data ? */
	if (eccmode == NAND_ECC_SOFT) {
		/* Read back previous written data, if col > 0 */
		if (col) {
			this->cmdfunc (mtd, NAND_CMD_READ0, 0, page);
			for (i = 0; i < col; i++)
				this->data_poi[i] = readb (this->IO_ADDR_R);
		}
		if ((col < this->eccsize) && (last >= this->eccsize)) {
			this->calculate_ecc (&this->data_poi[0], &(ecc_code[0]));
			for (i = 0; i < 3; i++)
				oob_data[oob_config[i]] = ecc_code[i];
		}
		/* Calculate and write the second ECC if we have enough data */
		if ((mtd->oobblock == 512) && (last == 512)) {
			this->calculate_ecc (&this->data_poi[256], &(ecc_code[3]));
			for (i = 3; i < 6; i++)
				oob_data[oob_config[i]] = ecc_code[i];
		} 
	} else {
		/* For hardware ECC skip ECC, if we have no full page write */
		if (eccmode != NAND_ECC_NONE && (col || last != mtd->oobblock))
			eccmode = NAND_ECC_NONE;
	}			

	/* Prepad for partial page programming !!! */
	for (i = 0; i < col; i++)
		this->data_poi[i] = 0xff;

	/* Postpad for partial page programming !!! oob is already padded */
	for (i = last; i < mtd->oobblock; i++)
		this->data_poi[i] = 0xff;

	/* Send command to begin auto page programming */
	this->cmdfunc (mtd, NAND_CMD_SEQIN, 0x00, page);

	/* Write out complete page of data, take care of eccmode */
	switch (this->eccmode) {
	/* No ecc and software ecc 3/256, write all */
	case NAND_ECC_NONE:
	case NAND_ECC_SOFT:
		for (i = 0; i < mtd->oobblock; i++) 
			writeb ( this->data_poi[i] , this->IO_ADDR_W);
		break;
		
	/* Hardware ecc 3 byte / 256 data, write first half, get ecc, then second, if 512 byte pagesize */	
	case NAND_ECC_HW3_256:		
		this->enable_hwecc (NAND_ECC_WRITE);	/* enable hardware ecc logic for write */
		for (i = 0; i < mtd->eccsize; i++) 
			writeb ( this->data_poi[i] , this->IO_ADDR_W);
		
		this->calculate_ecc (NULL, &(ecc_code[0]));
		for (i = 0; i < 3; i++)
			oob_data[oob_config[i]] = ecc_code[i];
			
		if (mtd->oobblock == 512) {
			this->enable_hwecc (NAND_ECC_WRITE);	/* enable hardware ecc logic for write*/
			for (i = mtd->eccsize; i < mtd->oobblock; i++) 
				writeb ( this->data_poi[i] , this->IO_ADDR_W);
			this->calculate_ecc (NULL, &(ecc_code[3]));
			for (i = 3; i < 6; i++)
				oob_data[oob_config[i]] = ecc_code[i];
		}
		break;
				
	/* Hardware ecc 3 byte / 512 byte data, write full page */	
	case NAND_ECC_HW3_512:	
		this->enable_hwecc (NAND_ECC_WRITE);	/* enable hardware ecc logic */
		for (i = 0; i < mtd->oobblock; i++) 
			writeb ( this->data_poi[i] , this->IO_ADDR_W);
		this->calculate_ecc (NULL, &(ecc_code[0]));
		for (i = 0; i < 3; i++)
			oob_data[oob_config[i]] = ecc_code[i];
		break;

	/* Hardware ecc 6 byte / 512 byte data, write full page */	
	case NAND_ECC_HW6_512:	
		this->enable_hwecc (NAND_ECC_WRITE);	/* enable hardware ecc logic */
		for (i = 0; i < mtd->oobblock; i++) 
			writeb ( this->data_poi[i] , this->IO_ADDR_W);
		this->calculate_ecc (NULL, &(ecc_code[0]));
		for (i = 0; i < 6; i++)
			oob_data[oob_config[i]] = ecc_code[i];
		break;
		
	default:
		printk (KERN_WARNING "Invalid NAND_ECC_MODE %d\n", this->eccmode);
		BUG();	
	}	
	
	/* Write out OOB data */
	for (i = 0; i <  mtd->oobsize; i++)
		writeb ( oob_data[i] , this->IO_ADDR_W);

	/* Send command to actually program the data */
	this->cmdfunc (mtd, NAND_CMD_PAGEPROG, -1, -1);

	/* call wait ready function */
	status = this->waitfunc (mtd, this, FL_WRITING);

	/* See if device thinks it succeeded */
	if (status & 0x01) {
		DEBUG (MTD_DEBUG_LEVEL0, "%s: " "Failed write, page 0x%08x, ", __FUNCTION__, page);
		return -EIO;
	}

#ifdef CONFIG_MTD_NAND_VERIFY_WRITE
	/*
	 * The NAND device assumes that it is always writing to
	 * a cleanly erased page. Hence, it performs its internal
	 * write verification only on bits that transitioned from
	 * 1 to 0. The device does NOT verify the whole page on a
	 * byte by byte basis. It is possible that the page was
	 * not completely erased or the page is becoming unusable
	 * due to wear. The read with ECC would catch the error
	 * later when the ECC page check fails, but we would rather
	 * catch it early in the page write stage. Better to write
	 * no data than invalid data.
	 */

	/* Send command to read back the page */
	this->cmdfunc (mtd, NAND_CMD_READ0, col, page);
	/* Loop through and verify the data */
	for (i = col; i < last; i++) {
		if (this->data_poi[i] != readb (this->IO_ADDR_R)) {
			DEBUG (MTD_DEBUG_LEVEL0, "%s: " "Failed write verify, page 0x%08x ", __FUNCTION__, page);
			return -EIO;
		}
	}