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Commit 9d75414b authored by David Woodhouse's avatar David Woodhouse
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[MTD NAND] Update CS553x NAND driver: Hardware ECC support, optimisations. 



- Implement HW ECC support,
- Provide read_buf() and write_buf() routines using memcpy
- Use on-flash bad block table
- Fix module refcounting
- Avoid read/modify/write in hwcontrol()
- Minor cosmetic fixes

Partly based on code and ideas from Tom Sylla <tom.sylla@amd.com>

Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent c3f8abf4

drivers/mtd/nand/cs553x_nand.c

+75 −27
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 * (C) 2005, 2006 Red Hat Inc.

 *

 * Author: David Woodhouse <dwmw2@infradead.org>

 *	   Tom Sylla <tom.sylla@amd.com>

 *

 * 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
@@ -22,6 +23,7 @@ 
#include <linux/pci.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/nand.h>

#include <linux/mtd/nand_ecc.h>

#include <linux/mtd/partitions.h>



#include <asm/msr.h>
@@ -87,11 +89,34 @@ 
#define CS_NAND_ECC_CLRECC	(1<<1)

#define CS_NAND_ECC_ENECC	(1<<0)



static void cs553x_read_buf(struct mtd_info *mtd, u_char *buf, int len)

{

	struct nand_chip *this = mtd->priv;



	while (unlikely(len > 0x800)) {

		memcpy_fromio(buf, this->IO_ADDR_R, 0x800);

		buf += 0x800;

		len -= 0x800;

	}

	memcpy_fromio(buf, this->IO_ADDR_R, len);

}



static void cs553x_write_buf(struct mtd_info *mtd, const u_char *buf, int len)

{

	struct nand_chip *this = mtd->priv;



	while (unlikely(len > 0x800)) {

		memcpy_toio(this->IO_ADDR_R, buf, 0x800);

		buf += 0x800;

		len -= 0x800;

	}

	memcpy_toio(this->IO_ADDR_R, buf, len);

}



static unsigned char cs553x_read_byte(struct mtd_info *mtd)

{

	struct nand_chip *this = mtd->priv;

	unsigned char foo = readb(this->IO_ADDR_R);

	return foo;

	return readb(this->IO_ADDR_R);

}



static void cs553x_write_byte(struct mtd_info *mtd, u_char byte)
@@ -110,35 +135,29 @@ static void cs553x_hwcontrol(struct mtd_info *mtd, int cmd) 
{

	struct nand_chip *this = mtd->priv;

	void __iomem *mmio_base = this->IO_ADDR_R;



	uint8_t old = readb(mmio_base + MM_NAND_CTL);

	unsigned char ctl;



	switch(cmd) {

	case NAND_CTL_SETCLE:

		old |= CS_NAND_CTL_CLE;

		ctl = CS_NAND_CTL_CLE;

		break;



	case NAND_CTL_CLRCLE:

		old &= ~CS_NAND_CTL_CLE;

		break;



	case NAND_CTL_SETALE:

		old |= CS_NAND_CTL_ALE;

		break;



	case NAND_CTL_CLRALE:

		old &= ~CS_NAND_CTL_ALE;

	case NAND_CTL_SETNCE:

		ctl = 0;

		break;



	case NAND_CTL_SETNCE:

		old &= ~CS_NAND_CTL_CE;

	case NAND_CTL_SETALE:

		ctl = CS_NAND_CTL_ALE;

		break;



	default:

	case NAND_CTL_CLRNCE:

		old |= CS_NAND_CTL_CE;

		ctl = CS_NAND_CTL_CE;

		break;

	}

	writeb(old, mmio_base + MM_NAND_CTL);

	writeb(ctl, mmio_base + MM_NAND_CTL);

}
@@ -151,6 +170,29 @@ static int cs553x_device_ready(struct mtd_info *mtd) 
	return (foo & CS_NAND_STS_FLASH_RDY) && !(foo & CS_NAND_CTLR_BUSY); 

}





static void cs_enable_hwecc(struct mtd_info *mtd, int mode)

{

	struct nand_chip *this = mtd->priv;

	void __iomem *mmio_base = this->IO_ADDR_R;



	writeb(0x07, mmio_base + MM_NAND_ECC_CTL);

}



static int cs_calculate_ecc(struct mtd_info *mtd, const u_char *dat, u_char *ecc_code)

{

	uint32_t ecc;

	struct nand_chip *this = mtd->priv;

	void __iomem *mmio_base = this->IO_ADDR_R;



	ecc = readl(mmio_base + MM_NAND_STS);



	ecc_code[1] = ecc >> 8;

	ecc_code[0] = ecc >> 16;

	ecc_code[2] = ecc >> 24;

	return 0;

}



static struct mtd_info *cs553x_mtd[4];



static int __init cs553x_init_one(int cs, int mmio, unsigned long adr)
@@ -178,8 +220,8 @@ static int __init cs553x_init_one(int cs, int mmio, unsigned long adr) 
	this = (struct nand_chip *) (&new_mtd[1]);



	/* Initialize structures */

	memset((char *) new_mtd, 0, sizeof(struct mtd_info));

	memset((char *) this, 0, sizeof(struct nand_chip));

	memset(new_mtd, 0, sizeof(struct mtd_info));

	memset(this, 0, sizeof(struct nand_chip));



	/* Link the private data with the MTD structure */

	new_mtd->priv = this;
@@ -196,13 +238,18 @@ static int __init cs553x_init_one(int cs, int mmio, unsigned long adr) 
	this->dev_ready = cs553x_device_ready;

	this->read_byte = cs553x_read_byte;

	this->write_byte = cs553x_write_byte;

	this->read_buf = cs553x_read_buf;

	this->write_buf = cs553x_write_buf;



	this->chip_delay = 0;



	/* 20 us command delay time */

	this->chip_delay = 20;

	this->eccmode = NAND_ECC_SOFT;

	this->eccmode = NAND_ECC_HW3_256;

	this->enable_hwecc  = cs_enable_hwecc;

	this->calculate_ecc = cs_calculate_ecc;

	this->correct_data  = nand_correct_data;

	

	/* Enable the following for a flash based bad block table */

	//	this->options = NAND_USE_FLASH_BBT;

	this->options = NAND_USE_FLASH_BBT | NAND_NO_AUTOINCR;



	/* Scan to find existance of the device */

	if (nand_scan(new_mtd, 1)) {
@@ -210,6 +257,7 @@ static int __init cs553x_init_one(int cs, int mmio, unsigned long adr) 
		goto out_ior;

	}



	new_mtd->owner = THIS_MODULE;

	cs553x_mtd[cs] = new_mtd;

	goto out;