[MTD] Add initial support for OneNAND flash chips

OneNAND is a new flash technology from Samsung with integrated SRAM
buffers and logic interface.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

6 files changed, 1689 insertions, 6 deletions

diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 843a1cbe0866..3dbfbafb3481 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -1,4 +1,4 @@
-# $Id: Kconfig,v 1.9 2005/06/16 08:49:29 sean Exp $
+# $Id: Kconfig,v 1.10 2005/07/11 10:39:27 gleixner Exp $
 
 menu "Memory Technology Devices (MTD)"
 
@@ -259,9 +259,9 @@ config RFD_FTL
 	---help---
 	  This provides support for the flash translation layer known 
 	  as the Resident Flash Disk (RFD), as used by the Embedded BIOS 
-	  of General Software.
-	  See http://www.gensw.com/pages/prod/bios/rfd.htm for further
-	  information.
+	  of General Software. There is a blurb at:
+
+		http://www.gensw.com/pages/prod/bios/rfd.htm
 
 source "drivers/mtd/chips/Kconfig"
 
@@ -271,5 +271,7 @@ source "drivers/mtd/devices/Kconfig"
 
 source "drivers/mtd/nand/Kconfig"
 
+source "drivers/mtd/onenand/Kconfig"
+
 endmenu
 
diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index cb16b7d478ce..fc9374407c2b 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -1,7 +1,7 @@
 #
 # Makefile for the memory technology device drivers.
 #
-# $Id: Makefile.common,v 1.6 2005/06/16 08:49:29 sean Exp $
+# $Id: Makefile.common,v 1.7 2005/07/11 10:39:27 gleixner Exp $
 
 # Core functionality.
 mtd-y				:= mtdcore.o
@@ -25,4 +25,4 @@ obj-$(CONFIG_RFD_FTL)		+= rfd_ftl.o mtd_blkdevs.o
 nftl-objs		:= nftlcore.o nftlmount.o
 inftl-objs		:= inftlcore.o inftlmount.o
 
-obj-y		+= chips/ maps/ devices/ nand/
+obj-y		+= chips/ maps/ devices/ nand/ onenand/
diff --git a/drivers/mtd/onenand/Kconfig b/drivers/mtd/onenand/Kconfig
new file mode 100644
index 000000000000..7d76ede984d8
--- /dev/null
+++ b/drivers/mtd/onenand/Kconfig
@@ -0,0 +1,32 @@
+#
+# linux/drivers/mtd/onenand/Kconfig
+#
+
+menu "OneNAND Flash Device Drivers (EXPERIMENTAL)"
+	depends on MTD != n && EXPERIMENTAL
+
+config MTD_ONENAND
+	tristate "OneNAND Device Support"
+	depends on MTD
+	help
+	  This enables support for accessing all type of OneNAND flash
+	  devices. For further information see
+	  <http://www.samsung.com/Products/Semiconductor/Flash/OneNAND_TM/index.htm>.
+
+config MTD_ONENAND_VERIFY_WRITE
+	bool "Verify OneNAND page writes"
+	depends on MTD_ONENAND
+	help
+	  This adds an extra check when data is written to the flash. The
+	  OneNAND flash device internally checks only bits transitioning
+	  from 1 to 0. There is a rare possibility that even though the
+	  device thinks the write was successful, a bit could have been
+	  flipped accidentaly due to device wear or something else.
+
+config MTD_ONENAND_OMAP
+	tristate "OneNAND Flash device on OMAP board"
+	depends on ARCH_OMAP && MTD_ONENAND
+	help
+	  Support for OneNAND flash on TI OMAP board.
+
+endmenu
diff --git a/drivers/mtd/onenand/Makefile b/drivers/mtd/onenand/Makefile
new file mode 100644
index 000000000000..f4e75864d8b5
--- /dev/null
+++ b/drivers/mtd/onenand/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile for the OneNAND MTD
+#
+
+# Core functionality.
+obj-$(CONFIG_MTD_ONENAND)		+= onenand_base.o
+
+# Board specific.
+obj-$(CONFIG_MTD_ONENAND_OMAP)		+= omap-onenand.o
diff --git a/drivers/mtd/onenand/omap-onenand.c b/drivers/mtd/onenand/omap-onenand.c
new file mode 100644
index 000000000000..56e1aec6b835
--- /dev/null
+++ b/drivers/mtd/onenand/omap-onenand.c
@@ -0,0 +1,178 @@
+/*
+ *  linux/drivers/mtd/onenand/omap-onenand.c
+ *
+ *  Copyright (c) 2005 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.com>
+ *
+ *  Derived from linux/drivers/mtd/nand/omap-nand-flash.c
+ *
+ * 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.
+ *
+ *  Overview:
+ *   This is a device driver for the OneNAND flash device for TI OMAP boards.
+ */
+
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/onenand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/tc.h>
+#include <asm/sizes.h>
+
+#define OMAP_ONENAND_FLASH_START1	OMAP_CS2A_PHYS
+#define OMAP_ONENAND_FLASH_START2	OMAP_CS0_PHYS
+/*
+ * MTD structure for OMAP board
+ */
+static struct mtd_info *omap_onenand_mtd = NULL;
+
+/*
+ * Define partitions for flash devices
+ */
+
+#ifdef CONFIG_MTD_PARTITIONS
+static struct mtd_partition static_partition[] = {
+	{
+		.name		= "X-Loader + U-Boot",
+		.offset		= 0,
+		.size		= SZ_128K,
+		.mask_flags	= MTD_WRITEABLE	/* force read-only */
+ 	},
+	{
+		.name		= "U-Boot Environment",
+		.offset		= MTDPART_OFS_APPEND,
+		.size		= SZ_128K,
+		.mask_flags	= MTD_WRITEABLE	/* force read-only */
+ 	},
+	{
+		.name		= "kernel",
+		.offset		= MTDPART_OFS_APPEND,
+		.size		= 2 * SZ_1M
+	},
+	{
+		.name		= "filesystem0",
+		.offset		= MTDPART_OFS_APPEND,
+		.size		= SZ_16M,
+	},
+	{
+		.name		= "filesystem1",
+		.offset		= MTDPART_OFS_APPEND,
+		.size		= MTDPART_SIZ_FULL,
+	},
+};
+
+const char *part_probes[] = { "cmdlinepart", NULL,  };
+
+#endif
+
+/* Scan to find existance of the device at base.
+   This also allocates oob and data internal buffers */
+static char onenand_name[] = "onenand";
+
+/*
+ * Main initialization routine
+ */
+static int __init omap_onenand_init (void)
+{
+	struct onenand_chip *this;
+	struct mtd_partition *dynamic_partition = 0;
+	int err = 0;
+
+	/* Allocate memory for MTD device structure and private data */
+	omap_onenand_mtd = kmalloc (sizeof(struct mtd_info) + sizeof (struct onenand_chip),
+				GFP_KERNEL);
+	if (!omap_onenand_mtd) {
+		printk (KERN_WARNING "Unable to allocate OneNAND MTD device structure.\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* Get pointer to private data */
+	this = (struct onenand_chip *) (&omap_onenand_mtd[1]);
+
+	/* Initialize structures */
+	memset((char *) omap_onenand_mtd, 0, sizeof(struct mtd_info) + sizeof(struct onenand_chip));
+
+	/* Link the private data with the MTD structure */
+	omap_onenand_mtd->priv = this;
+
+        /* try the first address */
+	this->base = ioremap(OMAP_ONENAND_FLASH_START1, SZ_128K);
+	omap_onenand_mtd->name = onenand_name;
+	if (onenand_scan(omap_onenand_mtd, 1)){
+		/* try the second address */
+		iounmap(this->base);
+		this->base = ioremap(OMAP_ONENAND_FLASH_START2, SZ_128K);
+		if (onenand_scan(omap_onenand_mtd, 1)) {
+			iounmap(this->base);
+                        err = -ENXIO;
+                        goto out_mtd;
+		}
+	}
+
+	/* Register the partitions */
+	switch (omap_onenand_mtd->size) {
+	case SZ_128M:
+	case SZ_64M:
+	case SZ_32M:
+#ifdef CONFIG_MTD_PARTITIONS
+		err = parse_mtd_partitions(omap_onenand_mtd, part_probes,
+					&dynamic_partition, 0);
+		if (err > 0)
+			err = add_mtd_partitions(omap_onenand_mtd,
+					dynamic_partition, err);
+		else if (1)
+			err = add_mtd_partitions(omap_onenand_mtd,
+					static_partition,
+					ARRAY_SIZE(static_partition));
+		else
+#endif
+			err = add_mtd_device(omap_onenand_mtd);
+		if (err)
+			goto out_buf;
+		break;
+
+	default:
+		printk(KERN_WARNING "Unsupported OneNAND device\n");
+		err = -ENXIO;
+		goto out_buf;
+	}
+
+	return 0;
+
+out_buf:
+	onenand_release(omap_onenand_mtd);
+	iounmap(this->base);
+out_mtd:
+	kfree(omap_onenand_mtd);
+out:
+	return err;
+}
+
+/*
+ * Clean up routine
+ */
+static void __exit omap_onenand_cleanup (void)
+{
+	struct onenand_chip *this = omap_onenand_mtd->priv;
+
+	/* onenand_release frees MTD partitions, MTD structure
+	   and onenand internal buffers */
+	onenand_release(omap_onenand_mtd);
+	iounmap(this->base);
+	kfree(omap_onenand_mtd);
+}
+
+module_init(omap_onenand_init);
+module_exit(omap_onenand_cleanup);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
+MODULE_DESCRIPTION("Glue layer for OneNAND flash on OMAP boards");
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
new file mode 100644
index 000000000000..bcce22ae3cb1
--- /dev/null
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -0,0 +1,1462 @@
+/*
+ *  linux/drivers/mtd/onenand/onenand_base.c
+ *
+ *  Copyright (C) 2005 Samsung Electronics
+ *  Kyungmin Park <kyungmin.park@samsung.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
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/onenand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+
+/**
+ * onenand_oob_64 - oob info for large (2KB) page
+ */
+static struct nand_oobinfo onenand_oob_64 = {
+	.useecc		= MTD_NANDECC_AUTOPLACE,
+	.eccbytes	= 20,
+	.eccpos		= {
+		8, 9, 10, 11, 12,
+		24, 25, 26, 27, 28,
+		40, 41, 42, 43, 44,
+		56, 57, 58, 59, 60,
+		},
+	.oobfree	= {
+		{2, 3}, {14, 2}, {18, 3}, {30, 2},
+		{24, 3}, {46, 2}, {40, 3}, {62, 2} }
+};
+
+/**
+ * onenand_oob_32 - oob info for middle (1KB) page
+ */
+static struct nand_oobinfo onenand_oob_32 = {
+	.useecc		= MTD_NANDECC_AUTOPLACE,
+	.eccbytes	= 10,
+	.eccpos		= {
+		8, 9, 10, 11, 12,
+		24, 25, 26, 27, 28,
+		},
+	.oobfree	= { {2, 3}, {14, 2}, {18, 3}, {30, 2} }
+};
+
+static const unsigned char ffchars[] = {
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 16 */
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 32 */
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 48 */
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+	0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,	/* 64 */
+};
+
+/**
+ * onenand_readw - [OneNAND Interface] Read OneNAND register
+ * @param addr		address to read
+ *
+ * Read OneNAND register
+ */
+static unsigned short onenand_readw(void __iomem *addr)
+{
+	return readw(addr);
+}
+
+/**
+ * onenand_writew - [OneNAND Interface] Write OneNAND register with value
+ * @param value		value to write
+ * @param addr		address to write
+ *
+ * Write OneNAND register with value
+ */
+static void onenand_writew(unsigned short value, void __iomem *addr)
+{
+	writew(value, addr);
+}
+
+/**
+ * onenand_block_address - [DEFAULT] Get block address
+ * @param device	the device id
+ * @param block		the block
+ * @return		translated block address if DDP, otherwise same
+ *
+ * Setup Start Address 1 Register (F100h)
+ */
+static int onenand_block_address(int device, int block)
+{
+	if (device & ONENAND_DEVICE_IS_DDP) {
+		/* Device Flash Core select, NAND Flash Block Address */
+		int dfs = 0, density, mask;
+
+		density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
+		mask = (1 << (density + 6));
+
+		if (block & mask)
+			dfs = 1;
+
+		return (dfs << ONENAND_DDP_SHIFT) | (block & (mask - 1));
+	}
+
+	return block;
+}
+
+/**
+ * onenand_bufferram_address - [DEFAULT] Get bufferram address
+ * @param device	the device id
+ * @param block		the block
+ * @return		set DBS value if DDP, otherwise 0
+ *
+ * Setup Start Address 2 Register (F101h) for DDP
+ */
+static int onenand_bufferram_address(int device, int block)
+{
+	if (device & ONENAND_DEVICE_IS_DDP) {
+		/* Device BufferRAM Select */
+		int dbs = 0, density, mask;
+
+		density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
+		mask = (1 << (density + 6));
+
+		if (block & mask)
+			dbs = 1;
+
+		return (dbs << ONENAND_DDP_SHIFT);
+	}
+
+	return 0;
+}
+
+/**
+ * onenand_page_address - [DEFAULT] Get page address
+ * @param page		the page address
+ * @param sector	the sector address
+ * @return		combined page and sector address
+ *
+ * Setup Start Address 8 Register (F107h)
+ */
+static int onenand_page_address(int page, int sector)
+{
+	/* Flash Page Address, Flash Sector Address */
+	int fpa, fsa;
+
+	fpa = page & ONENAND_FPA_MASK;
+	fsa = sector & ONENAND_FSA_MASK;
+
+	return ((fpa << ONENAND_FPA_SHIFT) | fsa);
+}
+
+/**
+ * onenand_buffer_address - [DEFAULT] Get buffer address
+ * @param dataram1	DataRAM index
+ * @param sectors	the sector address
+ * @param count		the number of sectors
+ * @return		the start buffer value
+ *
+ * Setup Start Buffer Register (F200h)
+ */
+static int onenand_buffer_address(int dataram1, int sectors, int count)
+{
+	int bsa, bsc;
+
+	/* BufferRAM Sector Address */
+	bsa = sectors & ONENAND_BSA_MASK;
+
+	if (dataram1)
+		bsa |= ONENAND_BSA_DATARAM1;	/* DataRAM1 */
+	else
+		bsa |= ONENAND_BSA_DATARAM0;	/* DataRAM0 */
+
+	/* BufferRAM Sector Count */
+	bsc = count & ONENAND_BSC_MASK;
+
+	return ((bsa << ONENAND_BSA_SHIFT) | bsc);
+}
+
+/**
+ * onenand_command - [DEFAULT] Send command to OneNAND device
+ * @param mtd		MTD device structure
+ * @param cmd		the command to be sent
+ * @param addr		offset to read from or write to
+ * @param len		number of bytes to read or write
+ *
+ * Send command to OneNAND device. This function is used for middle/large page
+ * devices (1KB/2KB Bytes per page)
+ */
+static int onenand_command(struct mtd_info *mtd, int cmd, loff_t addr, size_t len)
+{
+	struct onenand_chip *this = mtd->priv;
+	int value, readcmd = 0;
+	int block, page;
+	/* Now we use page size operation */
+	int sectors = 4, count = 4;
+
+	/* Address translation */
+	switch (cmd) {
+	case ONENAND_CMD_UNLOCK:
+	case ONENAND_CMD_LOCK:
+	case ONENAND_CMD_LOCK_TIGHT:
+		block = -1;
+		page = -1;
+		break;
+
+	case ONENAND_CMD_ERASE:
+	case ONENAND_CMD_BUFFERRAM:
+		block = (int) (addr >> this->erase_shift);
+		page = -1;
+		break;
+
+	default:
+		block = (int) (addr >> this->erase_shift);
+		page = (int) (addr >> this->page_shift);
+		page &= this->page_mask;
+		break;
+	}
+
+	/* NOTE: The setting order of the registers is very important! */
+	if (cmd == ONENAND_CMD_BUFFERRAM) {
+		/* Select DataRAM for DDP */
+		value = onenand_bufferram_address(this->device_id, block);
+		this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
+
+		/* Switch to the next data buffer */
+		ONENAND_SET_NEXT_BUFFERRAM(this);
+
+		return 0;
+	}
+
+	if (block != -1) {
+		/* Write 'DFS, FBA' of Flash */
+		value = onenand_block_address(this->device_id, block);
+		this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);
+	}
+
+	if (page != -1) {
+		int dataram;
+
+		switch (cmd) {
+		case ONENAND_CMD_READ:
+		case ONENAND_CMD_READOOB:
+			dataram = ONENAND_SET_NEXT_BUFFERRAM(this);
+			readcmd = 1;
+			break;
+
+		default:
+			dataram = ONENAND_CURRENT_BUFFERRAM(this);
+			break;
+		}
+
+		/* Write 'FPA, FSA' of Flash */
+		value = onenand_page_address(page, sectors);
+		this->write_word(value, this->base + ONENAND_REG_START_ADDRESS8);
+
+		/* Write 'BSA, BSC' of DataRAM */
+		value = onenand_buffer_address(dataram, sectors, count);
+		this->write_word(value, this->base + ONENAND_REG_START_BUFFER);
+			
+		if (readcmd) {
+			/* Select DataRAM for DDP */
+			value = onenand_bufferram_address(this->device_id, block);
+			this->write_word(value, this->base + ONENAND_REG_START_ADDRESS2);
+		}
+	}
+
+	/* Interrupt clear */
+	this->write_word(ONENAND_INT_CLEAR, this->base + ONENAND_REG_INTERRUPT);
+
+	/* Write command */
+	this->write_word(cmd, this->base + ONENAND_REG_COMMAND);
+
+	return 0;
+}
+
+/**
+ * onenand_wait - [DEFAULT] wait until the command is done
+ * @param mtd		MTD device structure
+ * @param state		state to select the max. timeout value
+ *
+ * Wait for command done. This applies to all OneNAND command
+ * Read can take up to 30us, erase up to 2ms and program up to 350us
+ * according to general OneNAND specs
+ */
+static int onenand_wait(struct mtd_info *mtd, int state)
+{
+	struct onenand_chip * this = mtd->priv;
+	unsigned long timeout;
+	unsigned int flags = ONENAND_INT_MASTER;
+	unsigned int interrupt = 0;
+	unsigned int ctrl, ecc;
+
+	/* The 20 msec is enough */
+	timeout = jiffies + msecs_to_jiffies(20);
+	while (time_before(jiffies, timeout)) {
+		interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
+
+		if (interrupt & flags)
+			break;
+
+		if (state != FL_READING)
+			cond_resched();
+	}
+	/* To get correct interrupt status in timeout case */
+	interrupt = this->read_word(this->base + ONENAND_REG_INTERRUPT);
+
+	ctrl = this->read_word(this->base + ONENAND_REG_CTRL_STATUS);
+
+	if (ctrl & ONENAND_CTRL_ERROR) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: controller error = 0x%04x", ctrl);
+		return -EIO;
+	}
+
+	if (ctrl & ONENAND_CTRL_LOCK) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: it's locked error = 0x%04x", ctrl);
+		return -EIO;
+	}
+
+	if (interrupt & ONENAND_INT_READ) {
+		ecc = this->read_word(this->base + ONENAND_REG_ECC_STATUS);
+		if (ecc & ONENAND_ECC_2BIT_ALL) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_wait: ECC error = 0x%04x", ecc);
+			return -EBADMSG;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * onenand_bufferram_offset - [DEFAULT] BufferRAM offset
+ * @param mtd		MTD data structure
+ * @param area		BufferRAM area
+ * @return		offset given area
+ *
+ * Return BufferRAM offset given area
+ */
+static inline int onenand_bufferram_offset(struct mtd_info *mtd, int area)
+{
+	struct onenand_chip *this = mtd->priv;
+
+	if (ONENAND_CURRENT_BUFFERRAM(this)) {
+		if (area == ONENAND_DATARAM)
+			return mtd->oobblock;
+		if (area == ONENAND_SPARERAM)
+			return mtd->oobsize;
+	}
+
+	return 0;
+}
+
+/**
+ * onenand_read_bufferram - [OneNAND Interface] Read the bufferram area
+ * @param mtd		MTD data structure
+ * @param area		BufferRAM area
+ * @param buffer	the databuffer to put/get data
+ * @param offset	offset to read from or write to
+ * @param count		number of bytes to read/write
+ *
+ * Read the BufferRAM area
+ */
+static int onenand_read_bufferram(struct mtd_info *mtd, int area,
+		unsigned char *buffer, int offset, size_t count)
+{
+	struct onenand_chip *this = mtd->priv;
+	void __iomem *bufferram;
+
+	bufferram = this->base + area;
+
+	bufferram += onenand_bufferram_offset(mtd, area);
+
+	memcpy(buffer, bufferram + offset, count);
+
+	return 0;
+}
+
+/**
+ * onenand_write_bufferram - [OneNAND Interface] Write the bufferram area
+ * @param mtd		MTD data structure
+ * @param area		BufferRAM area
+ * @param buffer	the databuffer to put/get data
+ * @param offset	offset to read from or write to
+ * @param count		number of bytes to read/write
+ *
+ * Write the BufferRAM area
+ */
+static int onenand_write_bufferram(struct mtd_info *mtd, int area,
+		const unsigned char *buffer, int offset, size_t count)
+{
+	struct onenand_chip *this = mtd->priv;
+	void __iomem *bufferram;
+
+	bufferram = this->base + area;
+
+	bufferram += onenand_bufferram_offset(mtd, area);
+
+	memcpy(bufferram + offset, buffer, count);
+
+	return 0;
+}
+
+/**
+ * onenand_check_bufferram - [GENERIC] Check BufferRAM information
+ * @param mtd		MTD data structure
+ * @param addr		address to check
+ * @return		1 if there are valid data, otherwise 0 
+ *
+ * Check bufferram if there is data we required
+ */
+static int onenand_check_bufferram(struct mtd_info *mtd, loff_t addr)
+{
+	struct onenand_chip *this = mtd->priv;
+	int block, page;
+	int i;
+	
+	block = (int) (addr >> this->erase_shift);
+	page = (int) (addr >> this->page_shift);
+	page &= this->page_mask;
+
+	i = ONENAND_CURRENT_BUFFERRAM(this);
+
+	/* Is there valid data? */
+	if (this->bufferram[i].block == block &&
+	    this->bufferram[i].page == page &&
+	    this->bufferram[i].valid)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * onenand_update_bufferram - [GENERIC] Update BufferRAM information
+ * @param mtd		MTD data structure
+ * @param addr		address to update
+ * @param valid		valid flag
+ *
+ * Update BufferRAM information
+ */
+static int onenand_update_bufferram(struct mtd_info *mtd, loff_t addr,
+		int valid)
+{
+	struct onenand_chip *this = mtd->priv;
+	int block, page;
+	int i;
+	
+	block = (int) (addr >> this->erase_shift);
+	page = (int) (addr >> this->page_shift);
+	page &= this->page_mask;
+
+	/* Invalidate BufferRAM */
+	for (i = 0; i < MAX_BUFFERRAM; i++) {
+		if (this->bufferram[i].block == block &&
+		    this->bufferram[i].page == page)
+			this->bufferram[i].valid = 0;
+	}
+
+	/* Update BufferRAM */
+	i = ONENAND_CURRENT_BUFFERRAM(this);
+	this->bufferram[i].block = block;
+	this->bufferram[i].page = page;
+	this->bufferram[i].valid = valid;
+
+	return 0;
+}
+
+/**
+ * onenand_get_device - [GENERIC] Get chip for selected access
+ * @param mtd		MTD device structure
+ * @param new_state	the state which is requested
+ *
+ * Get the device and lock it for exclusive access
+ */
+static void onenand_get_device(struct mtd_info *mtd, int new_state)
+{
+	struct onenand_chip *this = mtd->priv;
+	DECLARE_WAITQUEUE(wait, current);
+
+	/*
+	 * Grab the lock and see if the device is available
+	 */
+	while (1) {
+		spin_lock(&this->chip_lock);
+		if (this->state == FL_READY) {
+			this->state = new_state;
+			spin_unlock(&this->chip_lock);
+			break;
+		}
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		add_wait_queue(&this->wq, &wait);
+		spin_unlock(&this->chip_lock);
+		schedule();
+		remove_wait_queue(&this->wq, &wait);
+	}
+}
+
+/**
+ * onenand_release_device - [GENERIC] release chip
+ * @param mtd		MTD device structure
+ *
+ * Deselect, release chip lock and wake up anyone waiting on the device
+ */
+static void onenand_release_device(struct mtd_info *mtd)
+{
+	struct onenand_chip *this = mtd->priv;
+
+	/* Release the chip */
+	spin_lock(&this->chip_lock);
+	this->state = FL_READY;
+	wake_up(&this->wq);
+	spin_unlock(&this->chip_lock);
+}
+
+/**
+ * onenand_read_ecc - [MTD Interface] Read data with ECC
+ * @param mtd		MTD device structure
+ * @param from		offset to read from
+ * @param len		number of bytes to read
+ * @param retlen	pointer to variable to store the number of read bytes
+ * @param buf		the databuffer to put data
+ * @param oob_buf	filesystem supplied oob data buffer
+ * @param oobsel	oob selection structure
+ *
+ * OneNAND read with ECC
+ */
+static int onenand_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
+	size_t *retlen, u_char *buf,
+	u_char *oob_buf, struct nand_oobinfo *oobsel)
+{
+	struct onenand_chip *this = mtd->priv;
+	int read = 0, column;
+	int thislen;
+	int ret = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_ecc: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);
+
+	/* Do not allow reads past end of device */
+	if ((from + len) > mtd->size) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_ecc: Attempt read beyond end of device\n");
+		*retlen = 0;
+		return -EINVAL;
+	}
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_READING);
+
+	/* TODO handling oob */
+
+	while (read < len) {
+		thislen = min_t(int, mtd->oobblock, len - read);
+
+		column = from & (mtd->oobblock - 1);
+		if (column + thislen > mtd->oobblock)
+			thislen = mtd->oobblock - column;
+
+		if (!onenand_check_bufferram(mtd, from)) {
+			this->command(mtd, ONENAND_CMD_READ, from, mtd->oobblock);
+
+			ret = this->wait(mtd, FL_READING);
+			/* First copy data and check return value for ECC handling */
+			onenand_update_bufferram(mtd, from, 1);
+		}
+
+		this->read_bufferram(mtd, ONENAND_DATARAM, buf, column, thislen);
+
+		read += thislen;
+
+		if (read == len)
+			break;
+
+		if (ret) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_ecc: read failed = %d\n", ret);
+			goto out;
+		}
+
+		from += thislen;
+		buf += thislen;
+	}
+
+out:
+	/* Deselect and wake up anyone waiting on the device */
+	onenand_release_device(mtd);
+
+	/*
+	 * Return success, if no ECC failures, else -EBADMSG
+	 * fs driver will take care of that, because
+	 * retlen == desired len and result == -EBADMSG
+	 */
+	*retlen = read;
+	return ret;
+}
+
+/**
+ * onenand_read - [MTD Interface] MTD compability function for onenand_read_ecc
+ * @param mtd		MTD device structure
+ * @param from		offset to read from
+ * @param len		number of bytes to read
+ * @param retlen	pointer to variable to store the number of read bytes
+ * @param buf		the databuffer to put data
+ *
+ * This function simply calls onenand_read_ecc with oob buffer and oobsel = NULL
+*/
+static int onenand_read(struct mtd_info *mtd, loff_t from, size_t len,
+	size_t *retlen, u_char *buf)
+{
+	return onenand_read_ecc(mtd, from, len, retlen, buf, NULL, NULL);
+}
+
+/**
+ * onenand_read_oob - [MTD Interface] OneNAND read out-of-band
+ * @param mtd		MTD device structure
+ * @param from		offset to read from
+ * @param len		number of bytes to read
+ * @param retlen	pointer to variable to store the number of read bytes
+ * @param buf		the databuffer to put data
+ *
+ * OneNAND read out-of-band data from the spare area
+ */
+static int onenand_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
+	size_t *retlen, u_char *buf)
+{
+	struct onenand_chip *this = mtd->priv;
+	int read = 0, thislen, column;
+	int ret = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_read_oob: from = 0x%08x, len = %i\n", (unsigned int) from, (int) len);
+
+	/* Initialize return length value */
+	*retlen = 0;
+
+	/* Do not allow reads past end of device */
+	if (unlikely((from + len) > mtd->size)) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_oob: Attempt read beyond end of device\n");
+		return -EINVAL;
+	}
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_READING);
+
+	column = from & (mtd->oobsize - 1);
+
+	while (read < len) {
+		thislen = mtd->oobsize - column;
+		thislen = min_t(int, thislen, len);
+
+		this->command(mtd, ONENAND_CMD_READOOB, from, mtd->oobsize);
+
+		onenand_update_bufferram(mtd, from, 0);
+
+		ret = this->wait(mtd, FL_READING);
+		/* First copy data and check return value for ECC handling */
+
+		this->read_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);
+
+		read += thislen;
+
+		if (read == len)
+			break;
+
+		if (ret) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_read_oob: read failed = %d\n", ret);
+			goto out;
+		}
+
+		buf += thislen;
+
+		/* Read more? */
+		if (read < len) {
+			/* Page size */
+			from += mtd->oobblock;
+			column = 0;
+		}
+	}
+
+out:
+	/* Deselect and wake up anyone waiting on the device */
+	onenand_release_device(mtd);
+
+	*retlen = read;
+	return ret;
+}
+
+#ifdef CONFIG_MTD_ONENAND_VERIFY_WRITE
+/**
+ * onenand_verify_page - [GENERIC] verify the chip contents after a write
+ * @param mtd		MTD device structure
+ * @param buf		the databuffer to verify
+ * @param block		block address
+ * @param page		page address
+ *
+ * Check DataRAM area directly
+ */
+static int onenand_verify_page(struct mtd_info *mtd, u_char *buf,
+	loff_t addr, int block, int page)
+{
+	struct onenand_chip *this = mtd->priv;
+	void __iomem *dataram0, *dataram1;
+	int ret = 0;
+
+	this->command(mtd, ONENAND_CMD_READ, addr, mtd->oobblock);
+
+	ret = this->wait(mtd, FL_READING);
+	if (ret)
+		return ret;
+
+	onenand_update_bufferram(mtd, addr, 1);
+
+	/* Check, if the two dataram areas are same */
+	dataram0 = this->base + ONENAND_DATARAM;
+	dataram1 = dataram0 + mtd->oobblock;
+
+	if (memcmp(dataram0, dataram1, mtd->oobblock))
+		return -EBADMSG;
+	
+	return 0;
+}
+#else
+#define onenand_verify_page(...)	(0)
+#endif
+
+#define NOTALIGNED(x)	((x & (mtd->oobblock - 1)) != 0)
+
+/**
+ * onenand_write_ecc - [MTD Interface] OneNAND write with ECC
+ * @param mtd		MTD device structure
+ * @param to		offset to write to
+ * @param len		number of bytes to write
+ * @param retlen	pointer to variable to store the number of written bytes
+ * @param buf		the data to write
+ * @param eccbuf	filesystem supplied oob data buffer
+ * @param oobsel	oob selection structure
+ *
+ * OneNAND write with ECC
+ */
+static int onenand_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)
+{
+	struct onenand_chip *this = mtd->priv;
+	int written = 0;
+	int ret = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_ecc: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);
+
+	/* Initialize retlen, in case of early exit */
+	*retlen = 0;
+
+	/* Do not allow writes past end of device */
+	if (unlikely((to + len) > mtd->size)) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: Attempt write to past end of device\n");
+		return -EINVAL;
+	}
+
+	/* Reject writes, which are not page aligned */
+        if (unlikely(NOTALIGNED(to)) || unlikely(NOTALIGNED(len))) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: Attempt to write not page aligned data\n");
+                return -EINVAL;
+        }
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_WRITING);
+
+	/* Loop until all data write */
+	while (written < len) {
+		int thislen = min_t(int, mtd->oobblock, len - written);
+
+		this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobblock);
+
+		this->write_bufferram(mtd, ONENAND_DATARAM, buf, 0, thislen);
+		this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);
+
+		this->command(mtd, ONENAND_CMD_PROG, to, mtd->oobblock);
+
+		onenand_update_bufferram(mtd, to, 1);
+
+		ret = this->wait(mtd, FL_WRITING);
+		if (ret) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: write filaed %d\n", ret);
+			goto out;
+		}
+
+		written += thislen;
+
+		/* Only check verify write turn on */
+		ret = onenand_verify_page(mtd, (u_char *) buf, to, block, page);
+		if (ret) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_ecc: verify failed %d\n", ret);
+			goto out;
+		}
+
+		if (written == len)
+			break;
+
+		to += thislen;
+		buf += thislen;
+	}
+
+out:
+	/* Deselect and wake up anyone waiting on the device */
+	onenand_release_device(mtd);
+
+	*retlen = written;
+	
+	return ret;
+}
+
+/**
+ * onenand_write - [MTD Interface] compability function for onenand_write_ecc
+ * @param mtd		MTD device structure
+ * @param to		offset to write to
+ * @param len		number of bytes to write
+ * @param retlen	pointer to variable to store the number of written bytes
+ * @param buf		the data to write
+ *
+ * This function simply calls onenand_write_ecc
+ * with oob buffer and oobsel = NULL
+ */
+static int onenand_write(struct mtd_info *mtd, loff_t to, size_t len,
+	size_t *retlen, const u_char *buf)
+{
+	return onenand_write_ecc(mtd, to, len, retlen, buf, NULL, NULL);
+}
+
+/**
+ * onenand_write_oob - [MTD Interface] OneNAND write out-of-band
+ * @param mtd		MTD device structure
+ * @param to		offset to write to
+ * @param len		number of bytes to write
+ * @param retlen	pointer to variable to store the number of written bytes
+ * @param buf		the data to write
+ *
+ * OneNAND write out-of-band
+ */
+static int onenand_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
+	size_t *retlen, const u_char *buf)
+{
+	struct onenand_chip *this = mtd->priv;
+	int column, status;
+	int written = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_write_oob: to = 0x%08x, len = %i\n", (unsigned int) to, (int) len);
+
+	/* Initialize retlen, in case of early exit */
+	*retlen = 0;
+
+	/* Do not allow writes past end of device */
+	if (unlikely((to + len) > mtd->size)) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_write_oob: Attempt write to past end of device\n");
+		return -EINVAL;
+	}
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_WRITING);
+
+	/* Loop until all data write */
+	while (written < len) {
+		int thislen = min_t(int, mtd->oobsize, len - written);
+
+		column = to & (mtd->oobsize - 1);
+
+		this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobsize);
+
+		this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);
+		this->write_bufferram(mtd, ONENAND_SPARERAM, buf, column, thislen);
+
+		this->command(mtd, ONENAND_CMD_PROGOOB, to, mtd->oobsize);
+
+		onenand_update_bufferram(mtd, to, 0);
+
+		status = this->wait(mtd, FL_WRITING);
+		if (status)
+			goto out;
+
+		written += thislen;
+
+		if (written == len)
+			break;
+
+		to += thislen;
+		buf += thislen;
+	}
+
+out:
+	/* Deselect and wake up anyone waiting on the device */
+	onenand_release_device(mtd);
+
+	*retlen = written;
+	
+	return 0;
+}
+
+/**
+ * onenand_writev_ecc - [MTD Interface] write with iovec with ecc
+ * @param mtd		MTD device structure
+ * @param vecs		the iovectors to write
+ * @param count		number of vectors
+ * @param to		offset to write to
+ * @param retlen	pointer to variable to store the number of written bytes
+ * @param eccbuf	filesystem supplied oob data buffer
+ * @param oobsel	oob selection structure
+ *
+ * OneNAND write with iovec with ecc
+ */
+static int onenand_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)
+{
+	struct onenand_chip *this = mtd->priv;
+	unsigned char buffer[mtd->oobblock], *pbuf;
+	size_t total_len, len;
+	int i, written = 0;
+	int ret = 0;
+
+	/* Preset written len for early exit */
+	*retlen = 0;
+
+	/* Calculate total length of data */
+	total_len = 0;
+	for (i = 0; i < count; i++)
+		total_len += vecs[i].iov_len;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_writev_ecc: to = 0x%08x, len = %i, count = %ld\n", (unsigned int) to, (unsigned int) total_len, count);
+
+	/* Do not allow write past end of the device */
+	if (unlikely((to + total_len) > mtd->size)) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: Attempted write past end of device\n");
+		return -EINVAL;
+	}
+
+	/* Reject writes, which are not page aligned */
+        if (unlikely(NOTALIGNED(to)) || unlikely(NOTALIGNED(total_len))) {
+                DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: Attempt to write not page aligned data\n");
+                return -EINVAL;
+        }
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_WRITING);
+
+	/* TODO handling oob */
+	
+	/* Loop until all keve's data has been written */
+	len = 0;
+	while (count) {
+		pbuf = buffer;
+		/* 
+		 * If the given tuple is >= pagesize then
+		 * write it out from the iov
+		 */
+		if ((vecs->iov_len - len) >= mtd->oobblock) {
+			pbuf = vecs->iov_base + len;
+
+			len += mtd->oobblock;
+
+			/* Check, if we have to switch to the next tuple */
+			if (len >= (int) vecs->iov_len) {
+				vecs++;
+				len = 0;
+				count--;
+			}
+		} else {
+			int cnt = 0, thislen;
+			while (cnt < mtd->oobblock) {
+				thislen = min_t(int, mtd->oobblock - cnt, vecs->iov_len - len);
+				memcpy(buffer + cnt, vecs->iov_base + len, thislen);
+				cnt += thislen;
+				len += thislen;
+
+				/* Check, if we have to switch to the next tuple */
+				if (len >= (int) vecs->iov_len) {
+					vecs++;
+					len = 0;
+					count--;
+				}
+			}
+		}
+
+		this->command(mtd, ONENAND_CMD_BUFFERRAM, to, mtd->oobblock);
+
+		this->write_bufferram(mtd, ONENAND_DATARAM, pbuf, 0, mtd->oobblock);
+		this->write_bufferram(mtd, ONENAND_SPARERAM, ffchars, 0, mtd->oobsize);
+
+		this->command(mtd, ONENAND_CMD_PROG, to, mtd->oobblock);
+
+		onenand_update_bufferram(mtd, to, 1);
+
+		ret = this->wait(mtd, FL_WRITING);
+		if (ret) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: write failed %d\n", ret);
+			goto out;
+		}
+
+
+		/* Only check verify write turn on */
+		ret = onenand_verify_page(mtd, (u_char *) pbuf, to, block, page);
+		if (ret) {
+			DEBUG(MTD_DEBUG_LEVEL0, "onenand_writev_ecc: verify failed %d\n", ret);
+			goto out;
+		}
+
+		written += mtd->oobblock;
+
+		to += mtd->oobblock;
+	}
+
+out:
+	/* Deselect and wakt up anyone waiting on the device */
+	onenand_release_device(mtd);
+
+	*retlen = written;
+
+	return 0;
+}
+
+/**
+ * onenand_writev - [MTD Interface] compabilty function for onenand_writev_ecc
+ * @param mtd		MTD device structure
+ * @param vecs		the iovectors to write
+ * @param count		number of vectors
+ * @param to		offset to write to
+ * @param retlen	pointer to variable to store the number of written bytes
+ *
+ * OneNAND write with kvec. This just calls the ecc function
+ */
+static int onenand_writev(struct mtd_info *mtd, const struct kvec *vecs,
+	unsigned long count, loff_t to, size_t *retlen)
+{
+	return onenand_writev_ecc(mtd, vecs, count, to, retlen, NULL, NULL);
+}
+
+/**
+ * onenand_erase - [MTD Interface] erase block(s)
+ * @param mtd		MTD device structure
+ * @param instr		erase instruction
+ *
+ * Erase one ore more blocks
+ */
+static int onenand_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct onenand_chip *this = mtd->priv;
+	unsigned int block_size;
+	loff_t addr;
+	int len;
+	int ret = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_erase: start = 0x%08x, len = %i\n", (unsigned int) instr->addr, (unsigned int) instr->len);
+
+	block_size = (1 << this->erase_shift);
+
+	/* Start address must align on block boundary */
+	if (unlikely(instr->addr & (block_size - 1))) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Unaligned address\n");
+		return -EINVAL;
+	}
+
+	/* Length must align on block boundary */
+	if (unlikely(instr->len & (block_size - 1))) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Length not block aligned\n");
+		return -EINVAL;
+	}
+
+	/* Do not allow erase past end of device */
+	if (unlikely((instr->len + instr->addr) > mtd->size)) {
+		DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Erase past end of device\n");
+		return -EINVAL;
+	}
+
+	instr->fail_addr = 0xffffffff;
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_ERASING);
+
+	/* Loop throught the pages */
+	len = instr->len;
+	addr = instr->addr;
+
+	instr->state = MTD_ERASING;
+
+	while (len) {
+
+		/* TODO Check badblock */
+
+		this->command(mtd, ONENAND_CMD_ERASE, addr, block_size);
+
+		ret = this->wait(mtd, FL_ERASING);
+		/* Check, if it is write protected */
+		if (ret) {
+			if (ret == -EPERM)
+				DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Device is write protected!!!\n");
+			else
+				DEBUG(MTD_DEBUG_LEVEL0, "onenand_erase: Failed erase, block %d\n", (unsigned) (addr >> this->erase_shift));
+			instr->state = MTD_ERASE_FAILED;
+			instr->fail_addr = addr;
+			goto erase_exit;
+		}
+
+		len -= block_size;
+		addr += block_size;
+	}
+
+	instr->state = MTD_ERASE_DONE;
+
+erase_exit:
+
+	ret = instr->state == MTD_ERASE_DONE ? 0 : -EIO;
+	/* Do call back function */
+	if (!ret)
+		mtd_erase_callback(instr);
+
+	/* Deselect and wake up anyone waiting on the device */
+	onenand_release_device(mtd);
+
+	return ret;
+}
+
+/**
+ * onenand_sync - [MTD Interface] sync
+ * @param mtd		MTD device structure
+ *
+ * Sync is actually a wait for chip ready function
+ */
+static void onenand_sync(struct mtd_info *mtd)
+{
+	DEBUG(MTD_DEBUG_LEVEL3, "onenand_sync: called\n");
+
+	/* Grab the lock and see if the device is available */
+	onenand_get_device(mtd, FL_SYNCING);
+
+	/* Release it and go back */
+	onenand_release_device(mtd);
+}
+
+/**
+ * onenand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad
+ * @param mtd		MTD device structure
+ * @param ofs		offset relative to mtd start
+ */
+static int onenand_block_isbad(struct mtd_info *mtd, loff_t ofs)
+{
+	/*
+	 * TODO 
+	 * 1. Bad block table (BBT)
+	 *   -> using NAND BBT to support JFFS2
+	 * 2. Bad block management (BBM)
+	 *   -> bad block replace scheme
+	 *
+	 * Currently we do nothing
+	 */
+	return 0;
+}
+
+/**
+ * onenand_block_markbad - [MTD Interface] Mark the block at the given offset as bad
+ * @param mtd		MTD device structure
+ * @param ofs		offset relative to mtd start
+ */
+static int onenand_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+	/* see above */
+	return 0;
+}
+
+/**
+ * onenand_unlock - [MTD Interface] Unlock block(s)
+ * @param mtd		MTD device structure
+ * @param ofs		offset relative to mtd start
+ * @param len		number of bytes to unlock
+ *
+ * Unlock one or more blocks
+ */
+static int onenand_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+	struct onenand_chip *this = mtd->priv;
+	int start, end, block, value, status;
+
+	start = ofs >> this->erase_shift;
+	end = len >> this->erase_shift;
+
+	/* Continuous lock scheme */
+	if (this->options & ONENAND_CONT_LOCK) {
+		/* Set start block address */
+		this->write_word(start, this->base + ONENAND_REG_START_BLOCK_ADDRESS);
+		/* Set end block address */
+		this->write_word(end - 1, this->base + ONENAND_REG_END_BLOCK_ADDRESS);
+		/* Write unlock command */
+		this->command(mtd, ONENAND_CMD_UNLOCK, 0, 0);
+
+		/* There's no return value */
+		this->wait(mtd, FL_UNLOCKING);
+
+		/* Sanity check */
+		while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS)
+		    & ONENAND_CTRL_ONGO)
+			continue;
+
+		/* Check lock status */
+		status = this->read_word(this->base + ONENAND_REG_WP_STATUS);
+		if (!(status & ONENAND_WP_US))
+			printk(KERN_ERR "wp status = 0x%x\n", status);
+
+		return 0;
+	}
+
+	/* Block lock scheme */
+	for (block = start; block < end; block++) {
+		/* Set start block address */
+		this->write_word(block, this->base + ONENAND_REG_START_BLOCK_ADDRESS);
+		/* Write unlock command */
+		this->command(mtd, ONENAND_CMD_UNLOCK, 0, 0);
+
+		/* There's no return value */
+		this->wait(mtd, FL_UNLOCKING);
+
+		/* Sanity check */
+		while (this->read_word(this->base + ONENAND_REG_CTRL_STATUS)
+		    & ONENAND_CTRL_ONGO)
+			continue;
+
+		/* Set block address for read block status */
+		value = onenand_block_address(this->device_id, block);
+		this->write_word(value, this->base + ONENAND_REG_START_ADDRESS1);
+
+		/* Check lock status */
+		status = this->read_word(this->base + ONENAND_REG_WP_STATUS);
+		if (!(status & ONENAND_WP_US))
+			printk(KERN_ERR "block = %d, wp status = 0x%x\n", block, status);
+	}
+	
+	return 0;
+}
+
+/**
+ * onenand_print_device_info - Print device ID
+ * @param device        device ID
+ *
+ * Print device ID
+ */
+static void onenand_print_device_info(int device)
+{
+        int vcc, demuxed, ddp, density;
+
+        vcc = device & ONENAND_DEVICE_VCC_MASK;
+        demuxed = device & ONENAND_DEVICE_IS_DEMUX;
+        ddp = device & ONENAND_DEVICE_IS_DDP;
+        density = device >> ONENAND_DEVICE_DENSITY_SHIFT;
+        printk(KERN_INFO "%sOneNAND%s %dMB %sV 16-bit (0x%02x)\n",
+                demuxed ? "" : "Muxed ",
+                ddp ? "(DDP)" : "",
+                (16 << density),
+                vcc ? "2.65/3.3" : "1.8",
+                device);
+}
+
+static const struct onenand_manufacturers onenand_manuf_ids[] = {
+        {ONENAND_MFR_SAMSUNG, "Samsung"},
+        {ONENAND_MFR_UNKNOWN, "Unknown"}
+};
+
+/**
+ * onenand_check_maf - Check manufacturer ID
+ * @param manuf         manufacturer ID
+ *
+ * Check manufacturer ID
+ */
+static int onenand_check_maf(int manuf)
+{
+        int i;
+
+        for (i = 0; onenand_manuf_ids[i].id; i++) {
+                if (manuf == onenand_manuf_ids[i].id)
+                        break;
+        }
+
+        printk(KERN_DEBUG "OneNAND Manufacturer: %s\n",
+                onenand_manuf_ids[i].name);
+
+        return (i != ONENAND_MFR_UNKNOWN);
+}
+
+/**
+ * onenand_probe - [OneNAND Interface] Probe the OneNAND device
+ * @param mtd		MTD device structure
+ *
+ * OneNAND detection method:
+ *   Compare the the values from command with ones from register
+ */
+static int onenand_probe(struct mtd_info *mtd)
+{
+	struct onenand_chip *this = mtd->priv;
+	int bram_maf_id, bram_dev_id, maf_id, dev_id;
+	int version_id;
+	int density;
+
+	/* Send the command for reading device ID from BootRAM */
+	this->write_word(ONENAND_CMD_READID, this->base + ONENAND_BOOTRAM);
+
+	/* Read manufacturer and device IDs from BootRAM */
+	bram_maf_id = this->read_word(this->base + ONENAND_BOOTRAM + 0x0);
+	bram_dev_id = this->read_word(this->base + ONENAND_BOOTRAM + 0x2);
+
+	/* Check manufacturer ID */
+	if (onenand_check_maf(bram_maf_id))
+		return -ENXIO;
+
+	/* Reset OneNAND to read default register values */
+	this->write_word(ONENAND_CMD_RESET, this->base + ONENAND_BOOTRAM);
+
+	/* Read manufacturer and device IDs from Register */
+	maf_id = this->read_word(this->base + ONENAND_REG_MANUFACTURER_ID);
+	dev_id = this->read_word(this->base + ONENAND_REG_DEVICE_ID);
+
+	/* Check OneNAND device */
+	if (maf_id != bram_maf_id || dev_id != bram_dev_id)
+		return -ENXIO;
+
+	/* Flash device information */
+	onenand_print_device_info(dev_id);
+	this->device_id = dev_id;
+
+	density = dev_id >> ONENAND_DEVICE_DENSITY_SHIFT;
+	this->chipsize = (16 << density) << 20;
+
+	/* OneNAND page size & block size */
+	/* The data buffer size is equal to page size */
+	mtd->oobblock = this->read_word(this->base + ONENAND_REG_DATA_BUFFER_SIZE);
+	mtd->oobsize = mtd->oobblock >> 5;
+	/* Pagers per block is always 64 in OneNAND */
+	mtd->erasesize = mtd->oobblock << 6;
+
+	this->erase_shift = ffs(mtd->erasesize) - 1;
+	this->page_shift = ffs(mtd->oobblock) - 1;
+	this->ppb_shift = (this->erase_shift - this->page_shift);
+	this->page_mask = (mtd->erasesize / mtd->oobblock) - 1;
+
+	/* REVIST: Multichip handling */
+
+	mtd->size = this->chipsize;
+
+	/* Version ID */
+	version_id = this->read_word(this->base + ONENAND_REG_VERSION_ID);
+	printk(KERN_DEBUG "OneNAND version = 0x%04x\n", version_id);
+
+	/* Lock scheme */
+	if (density <= ONENAND_DEVICE_DENSITY_512Mb &&
+	    !(version_id >> ONENAND_VERSION_PROCESS_SHIFT)) {
+		printk(KERN_INFO "Lock scheme is Continues Lock\n");
+		this->options |= ONENAND_CONT_LOCK;
+	}
+	
+	return 0;
+}
+
+
+/**
+ * onenand_scan - [OneNAND Interface] Scan for the OneNAND device
+ * @param mtd		MTD device structure
+ * @param maxchips	Number of chips to scan for
+ *
+ * This fills out all the not initialized function pointers
+ * with the defaults.
+ * The flash ID is read and the mtd/chip structures are
+ * filled with the appropriate values.
+ */
+int onenand_scan(struct mtd_info *mtd, int maxchips)
+{
+	struct onenand_chip *this = mtd->priv;
+
+	if (!this->read_word)
+		this->read_word = onenand_readw;
+	if (!this->write_word)
+		this->write_word = onenand_writew;
+
+	if (!this->command)
+		this->command = onenand_command;
+	if (!this->wait)
+		this->wait = onenand_wait;
+
+	if (!this->read_bufferram)
+		this->read_bufferram = onenand_read_bufferram;
+	if (!this->write_bufferram)
+		this->write_bufferram = onenand_write_bufferram;
+
+	if (onenand_probe(mtd))
+		return -ENXIO;
+
+	this->state = FL_READY;
+	init_waitqueue_head(&this->wq);
+	spin_lock_init(&this->chip_lock);
+
+	switch (mtd->oobsize) {
+	case 64:
+		this->autooob = &onenand_oob_64;
+		break;
+
+	case 32:
+		this->autooob = &onenand_oob_32;
+		break;
+
+	default:
+		printk(KERN_WARNING "No OOB scheme defined for oobsize %d\n",
+			mtd->oobsize);
+		/* To prevent kernel oops */
+		this->autooob = &onenand_oob_32;
+		break;
+	}
+
+	memcpy(&mtd->oobinfo, this->autooob, sizeof(mtd->oobinfo));
+	
+	/* Fill in remaining MTD driver data */
+	mtd->type = MTD_NANDFLASH;
+	mtd->flags = MTD_CAP_NANDFLASH | MTD_ECC;
+	mtd->ecctype = MTD_ECC_SW;
+	mtd->erase = onenand_erase;
+	mtd->point = NULL;
+	mtd->unpoint = NULL;
+	mtd->read = onenand_read;
+	mtd->write = onenand_write;
+	mtd->read_ecc = onenand_read_ecc;
+	mtd->write_ecc = onenand_write_ecc;
+	mtd->read_oob = onenand_read_oob;
+	mtd->write_oob = onenand_write_oob;
+	mtd->readv = NULL;
+	mtd->readv_ecc = NULL;
+	mtd->writev = onenand_writev;
+	mtd->writev_ecc = onenand_writev_ecc;
+	mtd->sync = onenand_sync;
+	mtd->lock = NULL;
+	mtd->unlock = onenand_unlock;
+	mtd->suspend = NULL;
+	mtd->resume = NULL;
+	mtd->block_isbad = onenand_block_isbad;
+	mtd->block_markbad = onenand_block_markbad;
+	mtd->owner = THIS_MODULE;
+
+	/* Unlock whole block */
+	mtd->unlock(mtd, 0x0, this->chipsize);
+
+	return 0;
+}
+
+/**
+ * onenand_release - [OneNAND Interface] Free resources held by the OneNAND device
+ * @param mtd		MTD device structure
+ */
+void onenand_release(struct mtd_info *mtd)
+{
+#ifdef CONFIG_MTD_PARTITIONS
+	/* Deregister partitions */
+	del_mtd_partitions (mtd);
+#endif
+	/* Deregister the device */
+	del_mtd_device (mtd);
+}
+
+EXPORT_SYMBOL_GPL(onenand_scan);
+EXPORT_SYMBOL_GPL(onenand_release);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
+MODULE_DESCRIPTION("Generic OneNAND flash driver code");