[MTD] [NAND] Freescale i.MX2 NAND driver

This patch adds support for the integrated NAND flash controller of the
i.MX2 and i.MX3 family. It is tested on MX27 but should work on MX3
aswell.

Signed-off-by: Sascha Hauer <[e-mail]>
Acked-by: Juergen Beisert <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>

arch/arm/plat-mxc/include/mach/mxc_nand.h

···
+/*
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Sascha Hauer, [e-mail]
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#ifndef __ASM_ARCH_NAND_H
+#define __ASM_ARCH_NAND_H
+
+struct mxc_nand_platform_data {
+	int width;	/* data bus width in bytes */
+	int hw_ecc;	/* 0 if supress hardware ECC */
+};
+#endif /* __ASM_ARCH_NAND_H */

drivers/mtd/nand/Kconfig

···
 	  Enables support for NAND Flash chips wired onto Freescale PowerPC
 	  processor localbus with User-Programmable Machine support.
 
+config MTD_NAND_MXC
+	tristate "MXC NAND support"
+	depends on ARCH_MX2
+	help
+	  This enables the driver for the NAND flash controller on the
+	  MXC processors.
+
 endif # MTD_NAND

drivers/mtd/nand/Makefile

···
 obj-$(CONFIG_MTD_NAND_ORION)		+= orion_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_ELBC)		+= fsl_elbc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_UPM)		+= fsl_upm.o
+obj-$(CONFIG_MTD_NAND_MXC)		+= mxc_nand.o
 
 nand-objs := nand_base.o nand_bbt.o

drivers/mtd/nand/mxc_nand.c

···
+/*
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Sascha Hauer, [e-mail]
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <asm/mach/flash.h>
+#include <mach/mxc_nand.h>
+
+#define DRIVER_NAME "mxc_nand"
+
+/* Addresses for NFC registers */
+#define NFC_BUF_SIZE		0xE00
+#define NFC_BUF_ADDR		0xE04
+#define NFC_FLASH_ADDR		0xE06
+#define NFC_FLASH_CMD		0xE08
+#define NFC_CONFIG		0xE0A
+#define NFC_ECC_STATUS_RESULT	0xE0C
+#define NFC_RSLTMAIN_AREA	0xE0E
+#define NFC_RSLTSPARE_AREA	0xE10
+#define NFC_WRPROT		0xE12
+#define NFC_UNLOCKSTART_BLKADDR	0xE14
+#define NFC_UNLOCKEND_BLKADDR	0xE16
+#define NFC_NF_WRPRST		0xE18
+#define NFC_CONFIG1		0xE1A
+#define NFC_CONFIG2		0xE1C
+
+/* Addresses for NFC RAM BUFFER Main area 0 */
+#define MAIN_AREA0		0x000
+#define MAIN_AREA1		0x200
+#define MAIN_AREA2		0x400
+#define MAIN_AREA3		0x600
+
+/* Addresses for NFC SPARE BUFFER Spare area 0 */
+#define SPARE_AREA0		0x800
+#define SPARE_AREA1		0x810
+#define SPARE_AREA2		0x820
+#define SPARE_AREA3		0x830
+
+/* Set INT to 0, FCMD to 1, rest to 0 in NFC_CONFIG2 Register
+ * for Command operation */
+#define NFC_CMD            0x1
+
+/* Set INT to 0, FADD to 1, rest to 0 in NFC_CONFIG2 Register
+ * for Address operation */
+#define NFC_ADDR           0x2
+
+/* Set INT to 0, FDI to 1, rest to 0 in NFC_CONFIG2 Register
+ * for Input operation */
+#define NFC_INPUT          0x4
+
+/* Set INT to 0, FDO to 001, rest to 0 in NFC_CONFIG2 Register
+ * for Data Output operation */
+#define NFC_OUTPUT         0x8
+
+/* Set INT to 0, FD0 to 010, rest to 0 in NFC_CONFIG2 Register
+ * for Read ID operation */
+#define NFC_ID             0x10
+
+/* Set INT to 0, FDO to 100, rest to 0 in NFC_CONFIG2 Register
+ * for Read Status operation */
+#define NFC_STATUS         0x20
+
+/* Set INT to 1, rest to 0 in NFC_CONFIG2 Register for Read
+ * Status operation */
+#define NFC_INT            0x8000
+
+#define NFC_SP_EN           (1 << 2)
+#define NFC_ECC_EN          (1 << 3)
+#define NFC_INT_MSK         (1 << 4)
+#define NFC_BIG             (1 << 5)
+#define NFC_RST             (1 << 6)
+#define NFC_CE              (1 << 7)
+#define NFC_ONE_CYCLE       (1 << 8)
+
+struct mxc_nand_host {
+	struct mtd_info		mtd;
+	struct nand_chip	nand;
+	struct mtd_partition	*parts;
+	struct device		*dev;
+
+	void __iomem		*regs;
+	int			spare_only;
+	int			status_request;
+	int			pagesize_2k;
+	uint16_t		col_addr;
+	struct clk		*clk;
+	int			clk_act;
+	int			irq;
+
+	wait_queue_head_t	irq_waitq;
+};
+
+/* Define delays in microsec for NAND device operations */
+#define TROP_US_DELAY   2000
+/* Macros to get byte and bit positions of ECC */
+#define COLPOS(x)  ((x) >> 3)
+#define BITPOS(x) ((x) & 0xf)
+
+/* Define single bit Error positions in Main & Spare area */
+#define MAIN_SINGLEBIT_ERROR 0x4
+#define SPARE_SINGLEBIT_ERROR 0x1
+
+/* OOB placement block for use with hardware ecc generation */
+static struct nand_ecclayout nand_hw_eccoob_8 = {
+	.eccbytes = 5,
+	.eccpos = {6, 7, 8, 9, 10},
+	.oobfree = {{0, 5}, {11, 5}, }
+};
+
+static struct nand_ecclayout nand_hw_eccoob_16 = {
+	.eccbytes = 5,
+	.eccpos = {6, 7, 8, 9, 10},
+	.oobfree = {{0, 6}, {12, 4}, }
+};
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *part_probes[] = { "RedBoot", "cmdlinepart", NULL };
+#endif
+
+static irqreturn_t mxc_nfc_irq(int irq, void *dev_id)
+{
+	struct mxc_nand_host *host = dev_id;
+
+	uint16_t tmp;
+
+	tmp = readw(host->regs + NFC_CONFIG1);
+	tmp |= NFC_INT_MSK; /* Disable interrupt */
+	writew(tmp, host->regs + NFC_CONFIG1);
+
+	wake_up(&host->irq_waitq);
+
+	return IRQ_HANDLED;
+}
+
+/* This function polls the NANDFC to wait for the basic operation to
+ * complete by checking the INT bit of config2 register.
+ */
+static void wait_op_done(struct mxc_nand_host *host, int max_retries,
+				uint16_t param, int useirq)
+{
+	uint32_t tmp;
+
+	if (useirq) {
+		if ((readw(host->regs + NFC_CONFIG2) & NFC_INT) == 0) {
+
+			tmp = readw(host->regs + NFC_CONFIG1);
+			tmp  &= ~NFC_INT_MSK;	/* Enable interrupt */
+			writew(tmp, host->regs + NFC_CONFIG1);
+
+			wait_event(host->irq_waitq,
+				readw(host->regs + NFC_CONFIG2) & NFC_INT);
+
+			tmp = readw(host->regs + NFC_CONFIG2);
+			tmp  &= ~NFC_INT;
+			writew(tmp, host->regs + NFC_CONFIG2);
+		}
+	} else {
+		while (max_retries-- > 0) {
+			if (readw(host->regs + NFC_CONFIG2) & NFC_INT) {
+				tmp = readw(host->regs + NFC_CONFIG2);
+				tmp  &= ~NFC_INT;
+				writew(tmp, host->regs + NFC_CONFIG2);
+				break;
+			}
+			udelay(1);
+		}
+		if (max_retries <= 0)
+			DEBUG(MTD_DEBUG_LEVEL0, "%s(%d): INT not set\n",
+			      __func__, param);
+	}
+}
+
+/* This function issues the specified command to the NAND device and
+ * waits for completion. */
+static void send_cmd(struct mxc_nand_host *host, uint16_t cmd, int useirq)
+{
+	DEBUG(MTD_DEBUG_LEVEL3, "send_cmd(host, 0x%x, %d)\n", cmd, useirq);
+
+	writew(cmd, host->regs + NFC_FLASH_CMD);
+	writew(NFC_CMD, host->regs + NFC_CONFIG2);
+
+	/* Wait for operation to complete */
+	wait_op_done(host, TROP_US_DELAY, cmd, useirq);
+}
+
+/* This function sends an address (or partial address) to the
+ * NAND device. The address is used to select the source/destination for
+ * a NAND command. */
+static void send_addr(struct mxc_nand_host *host, uint16_t addr, int islast)
+{
+	DEBUG(MTD_DEBUG_LEVEL3, "send_addr(host, 0x%x %d)\n", addr, islast);
+
+	writew(addr, host->regs + NFC_FLASH_ADDR);
+	writew(NFC_ADDR, host->regs + NFC_CONFIG2);
+
+	/* Wait for operation to complete */
+	wait_op_done(host, TROP_US_DELAY, addr, islast);
+}
+
+/* This function requests the NANDFC to initate the transfer
+ * of data currently in the NANDFC RAM buffer to the NAND device. */
+static void send_prog_page(struct mxc_nand_host *host, uint8_t buf_id,
+			int spare_only)
+{
+	DEBUG(MTD_DEBUG_LEVEL3, "send_prog_page (%d)\n", spare_only);
+
+	/* NANDFC buffer 0 is used for page read/write */
+	writew(buf_id, host->regs + NFC_BUF_ADDR);
+
+	/* Configure spare or page+spare access */
+	if (!host->pagesize_2k) {
+		uint16_t config1 = readw(host->regs + NFC_CONFIG1);
+		if (spare_only)
+			config1 |= NFC_SP_EN;
+		else
+			config1 &= ~(NFC_SP_EN);
+		writew(config1, host->regs + NFC_CONFIG1);
+	}
+
+	writew(NFC_INPUT, host->regs + NFC_CONFIG2);
+
+	/* Wait for operation to complete */
+	wait_op_done(host, TROP_US_DELAY, spare_only, true);
+}
+
+/* Requests NANDFC to initated the transfer of data from the
+ * NAND device into in the NANDFC ram buffer. */
+static void send_read_page(struct mxc_nand_host *host, uint8_t buf_id,
+		int spare_only)
+{
+	DEBUG(MTD_DEBUG_LEVEL3, "send_read_page (%d)\n", spare_only);
+
+	/* NANDFC buffer 0 is used for page read/write */
+	writew(buf_id, host->regs + NFC_BUF_ADDR);
+
+	/* Configure spare or page+spare access */
+	if (!host->pagesize_2k) {
+		uint32_t config1 = readw(host->regs + NFC_CONFIG1);
+		if (spare_only)
+			config1 |= NFC_SP_EN;
+		else
+			config1 &= ~NFC_SP_EN;
+		writew(config1, host->regs + NFC_CONFIG1);
+	}
+
+	writew(NFC_OUTPUT, host->regs + NFC_CONFIG2);
+
+	/* Wait for operation to complete */
+	wait_op_done(host, TROP_US_DELAY, spare_only, true);
+}
+
+/* Request the NANDFC to perform a read of the NAND device ID. */
+static void send_read_id(struct mxc_nand_host *host)
+{
+	struct nand_chip *this = &host->nand;
+	uint16_t tmp;
+
+	/* NANDFC buffer 0 is used for device ID output */
+	writew(0x0, host->regs + NFC_BUF_ADDR);
+
+	/* Read ID into main buffer */
+	tmp = readw(host->regs + NFC_CONFIG1);
+	tmp &= ~NFC_SP_EN;
+	writew(tmp, host->regs + NFC_CONFIG1);
+
+	writew(NFC_ID, host->regs + NFC_CONFIG2);
+
+	/* Wait for operation to complete */
+	wait_op_done(host, TROP_US_DELAY, 0, true);
+
+	if (this->options & NAND_BUSWIDTH_16) {
+		void __iomem *main_buf = host->regs + MAIN_AREA0;
+		/* compress the ID info */
+		writeb(readb(main_buf + 2), main_buf + 1);
+		writeb(readb(main_buf + 4), main_buf + 2);
+		writeb(readb(main_buf + 6), main_buf + 3);
+		writeb(readb(main_buf + 8), main_buf + 4);
+		writeb(readb(main_buf + 10), main_buf + 5);
+	}
+}
+
+/* This function requests the NANDFC to perform a read of the
+ * NAND device status and returns the current status. */
+static uint16_t get_dev_status(struct mxc_nand_host *host)
+{
+	void __iomem *main_buf = host->regs + MAIN_AREA1;
+	uint32_t store;
+	uint16_t ret, tmp;
+	/* Issue status request to NAND device */
+
+	/* store the main area1 first word, later do recovery */
+	store = readl(main_buf);
+	/* NANDFC buffer 1 is used for device status to prevent
+	 * corruption of read/write buffer on status requests. */
+	writew(1, host->regs + NFC_BUF_ADDR);
+
+	/* Read status into main buffer */
+	tmp = readw(host->regs + NFC_CONFIG1);
+	tmp &= ~NFC_SP_EN;
+	writew(tmp, host->regs + NFC_CONFIG1);
+
+	writew(NFC_STATUS, host->regs + NFC_CONFIG2);
+
+	/* Wait for operation to complete */
+	wait_op_done(host, TROP_US_DELAY, 0, true);
+
+	/* Status is placed in first word of main buffer */
+	/* get status, then recovery area 1 data */
+	ret = readw(main_buf);
+	writel(store, main_buf);
+
+	return ret;
+}
+
+/* This functions is used by upper layer to checks if device is ready */
+static int mxc_nand_dev_ready(struct mtd_info *mtd)
+{
+	/*
+	 * NFC handles R/B internally. Therefore, this function
+	 * always returns status as ready.
+	 */
+	return 1;
+}
+
+static void mxc_nand_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	/*
+	 * If HW ECC is enabled, we turn it on during init. There is
+	 * no need to enable again here.
+	 */
+}
+
+static int mxc_nand_correct_data(struct mtd_info *mtd, u_char *dat,
+				 u_char *read_ecc, u_char *calc_ecc)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+
+	/*
+	 * 1-Bit errors are automatically corrected in HW.  No need for
+	 * additional correction.  2-Bit errors cannot be corrected by
+	 * HW ECC, so we need to return failure
+	 */
+	uint16_t ecc_status = readw(host->regs + NFC_ECC_STATUS_RESULT);
+
+	if (((ecc_status & 0x3) == 2) || ((ecc_status >> 2) == 2)) {
+		DEBUG(MTD_DEBUG_LEVEL0,
+		      "MXC_NAND: HWECC uncorrectable 2-bit ECC error\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int mxc_nand_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
+				  u_char *ecc_code)
+{
+	return 0;
+}
+
+static u_char mxc_nand_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+	uint8_t ret = 0;
+	uint16_t col, rd_word;
+	uint16_t __iomem *main_buf = host->regs + MAIN_AREA0;
+	uint16_t __iomem *spare_buf = host->regs + SPARE_AREA0;
+
+	/* Check for status request */
+	if (host->status_request)
+		return get_dev_status(host) & 0xFF;
+
+	/* Get column for 16-bit access */
+	col = host->col_addr >> 1;
+
+	/* If we are accessing the spare region */
+	if (host->spare_only)
+		rd_word = readw(&spare_buf[col]);
+	else
+		rd_word = readw(&main_buf[col]);
+
+	/* Pick upper/lower byte of word from RAM buffer */
+	if (host->col_addr & 0x1)
+		ret = (rd_word >> 8) & 0xFF;
+	else
+		ret = rd_word & 0xFF;
+
+	/* Update saved column address */
+	host->col_addr++;
+
+	return ret;
+}
+
+static uint16_t mxc_nand_read_word(struct mtd_info *mtd)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+	uint16_t col, rd_word, ret;
+	uint16_t __iomem *p;
+
+	DEBUG(MTD_DEBUG_LEVEL3,
+	      "mxc_nand_read_word(col = %d)\n", host->col_addr);
+
+	col = host->col_addr;
+	/* Adjust saved column address */
+	if (col < mtd->writesize && host->spare_only)
+		col += mtd->writesize;
+
+	if (col < mtd->writesize)
+		p = (host->regs + MAIN_AREA0) + (col >> 1);
+	else
+		p = (host->regs + SPARE_AREA0) + ((col - mtd->writesize) >> 1);
+
+	if (col & 1) {
+		rd_word = readw(p);
+		ret = (rd_word >> 8) & 0xff;
+		rd_word = readw(&p[1]);
+		ret |= (rd_word << 8) & 0xff00;
+
+	} else
+		ret = readw(p);
+
+	/* Update saved column address */
+	host->col_addr = col + 2;
+
+	return ret;
+}
+
+/* Write data of length len to buffer buf. The data to be
+ * written on NAND Flash is first copied to RAMbuffer. After the Data Input
+ * Operation by the NFC, the data is written to NAND Flash */
+static void mxc_nand_write_buf(struct mtd_info *mtd,
+				const u_char *buf, int len)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+	int n, col, i = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3,
+	      "mxc_nand_write_buf(col = %d, len = %d)\n", host->col_addr,
+	      len);
+
+	col = host->col_addr;
+
+	/* Adjust saved column address */
+	if (col < mtd->writesize && host->spare_only)
+		col += mtd->writesize;
+
+	n = mtd->writesize + mtd->oobsize - col;
+	n = min(len, n);
+
+	DEBUG(MTD_DEBUG_LEVEL3,
+	      "%s:%d: col = %d, n = %d\n", __func__, __LINE__, col, n);
+
+	while (n) {
+		void __iomem *p;
+
+		if (col < mtd->writesize)
+			p = host->regs + MAIN_AREA0 + (col & ~3);
+		else
+			p = host->regs + SPARE_AREA0 -
+						mtd->writesize + (col & ~3);
+
+		DEBUG(MTD_DEBUG_LEVEL3, "%s:%d: p = %p\n", __func__,
+		      __LINE__, p);
+
+		if (((col | (int)&buf[i]) & 3) || n < 16) {
+			uint32_t data = 0;
+
+			if (col & 3 || n < 4)
+				data = readl(p);
+
+			switch (col & 3) {
+			case 0:
+				if (n) {
+					data = (data & 0xffffff00) |
+					    (buf[i++] << 0);
+					n--;
+					col++;
+				}
+			case 1:
+				if (n) {
+					data = (data & 0xffff00ff) |
+					    (buf[i++] << 8);
+					n--;
+					col++;
+				}
+			case 2:
+				if (n) {
+					data = (data & 0xff00ffff) |
+					    (buf[i++] << 16);
+					n--;
+					col++;
+				}
+			case 3:
+				if (n) {
+					data = (data & 0x00ffffff) |
+					    (buf[i++] << 24);
+					n--;
+					col++;
+				}
+			}
+
+			writel(data, p);
+		} else {
+			int m = mtd->writesize - col;
+
+			if (col >= mtd->writesize)
+				m += mtd->oobsize;
+
+			m = min(n, m) & ~3;
+
+			DEBUG(MTD_DEBUG_LEVEL3,
+			      "%s:%d: n = %d, m = %d, i = %d, col = %d\n",
+			      __func__,  __LINE__, n, m, i, col);
+
+			memcpy(p, &buf[i], m);
+			col += m;
+			i += m;
+			n -= m;
+		}
+	}
+	/* Update saved column address */
+	host->col_addr = col;
+}
+
+/* Read the data buffer from the NAND Flash. To read the data from NAND
+ * Flash first the data output cycle is initiated by the NFC, which copies
+ * the data to RAMbuffer. This data of length len is then copied to buffer buf.
+ */
+static void mxc_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+	int n, col, i = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL3,
+	      "mxc_nand_read_buf(col = %d, len = %d)\n", host->col_addr, len);
+
+	col = host->col_addr;
+
+	/* Adjust saved column address */
+	if (col < mtd->writesize && host->spare_only)
+		col += mtd->writesize;
+
+	n = mtd->writesize + mtd->oobsize - col;
+	n = min(len, n);
+
+	while (n) {
+		void __iomem *p;
+
+		if (col < mtd->writesize)
+			p = host->regs + MAIN_AREA0 + (col & ~3);
+		else
+			p = host->regs + SPARE_AREA0 -
+					mtd->writesize + (col & ~3);
+
+		if (((col | (int)&buf[i]) & 3) || n < 16) {
+			uint32_t data;
+
+			data = readl(p);
+			switch (col & 3) {
+			case 0:
+				if (n) {
+					buf[i++] = (uint8_t) (data);
+					n--;
+					col++;
+				}
+			case 1:
+				if (n) {
+					buf[i++] = (uint8_t) (data >> 8);
+					n--;
+					col++;
+				}
+			case 2:
+				if (n) {
+					buf[i++] = (uint8_t) (data >> 16);
+					n--;
+					col++;
+				}
+			case 3:
+				if (n) {
+					buf[i++] = (uint8_t) (data >> 24);
+					n--;
+					col++;
+				}
+			}
+		} else {
+			int m = mtd->writesize - col;
+
+			if (col >= mtd->writesize)
+				m += mtd->oobsize;
+
+			m = min(n, m) & ~3;
+			memcpy(&buf[i], p, m);
+			col += m;
+			i += m;
+			n -= m;
+		}
+	}
+	/* Update saved column address */
+	host->col_addr = col;
+
+}
+
+/* Used by the upper layer to verify the data in NAND Flash
+ * with the data in the buf. */
+static int mxc_nand_verify_buf(struct mtd_info *mtd,
+				const u_char *buf, int len)
+{
+	return -EFAULT;
+}
+
+/* This function is used by upper layer for select and
+ * deselect of the NAND chip */
+static void mxc_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+
+#ifdef CONFIG_MTD_NAND_MXC_FORCE_CE
+	if (chip > 0) {
+		DEBUG(MTD_DEBUG_LEVEL0,
+		      "ERROR:  Illegal chip select (chip = %d)\n", chip);
+		return;
+	}
+
+	if (chip == -1) {
+		writew(readw(host->regs + NFC_CONFIG1) & ~NFC_CE,
+				host->regs + NFC_CONFIG1);
+		return;
+	}
+
+	writew(readw(host->regs + NFC_CONFIG1) | NFC_CE,
+			host->regs + NFC_CONFIG1);
+#endif
+
+	switch (chip) {
+	case -1:
+		/* Disable the NFC clock */
+		if (host->clk_act) {
+			clk_disable(host->clk);
+			host->clk_act = 0;
+		}
+		break;
+	case 0:
+		/* Enable the NFC clock */
+		if (!host->clk_act) {
+			clk_enable(host->clk);
+			host->clk_act = 1;
+		}
+		break;
+
+	default:
+		break;
+	}
+}
+
+/* Used by the upper layer to write command to NAND Flash for
+ * different operations to be carried out on NAND Flash */
+static void mxc_nand_command(struct mtd_info *mtd, unsigned command,
+				int column, int page_addr)
+{
+	struct nand_chip *nand_chip = mtd->priv;
+	struct mxc_nand_host *host = nand_chip->priv;
+	int useirq = true;
+
+	DEBUG(MTD_DEBUG_LEVEL3,
+	      "mxc_nand_command (cmd = 0x%x, col = 0x%x, page = 0x%x)\n",
+	      command, column, page_addr);
+
+	/* Reset command state information */
+	host->status_request = false;
+
+	/* Command pre-processing step */
+	switch (command) {
+
+	case NAND_CMD_STATUS:
+		host->col_addr = 0;
+		host->status_request = true;
+		break;
+
+	case NAND_CMD_READ0:
+		host->col_addr = column;
+		host->spare_only = false;
+		useirq = false;
+		break;
+
+	case NAND_CMD_READOOB:
+		host->col_addr = column;
+		host->spare_only = true;
+		useirq = false;
+		if (host->pagesize_2k)
+			command = NAND_CMD_READ0; /* only READ0 is valid */
+		break;
+
+	case NAND_CMD_SEQIN:
+		if (column >= mtd->writesize) {
+			/*
+			 * FIXME: before send SEQIN command for write OOB,
+			 * We must read one page out.
+			 * For K9F1GXX has no READ1 command to set current HW
+			 * pointer to spare area, we must write the whole page
+			 * including OOB together.
+			 */
+			if (host->pagesize_2k)
+				/* call ourself to read a page */
+				mxc_nand_command(mtd, NAND_CMD_READ0, 0,
+						page_addr);
+
+			host->col_addr = column - mtd->writesize;
+			host->spare_only = true;
+
+			/* Set program pointer to spare region */
+			if (!host->pagesize_2k)
+				send_cmd(host, NAND_CMD_READOOB, false);
+		} else {
+			host->spare_only = false;
+			host->col_addr = column;
+
+			/* Set program pointer to page start */
+			if (!host->pagesize_2k)
+				send_cmd(host, NAND_CMD_READ0, false);
+		}
+		useirq = false;
+		break;
+
+	case NAND_CMD_PAGEPROG:
+		send_prog_page(host, 0, host->spare_only);
+
+		if (host->pagesize_2k) {
+			/* data in 4 areas datas */
+			send_prog_page(host, 1, host->spare_only);
+			send_prog_page(host, 2, host->spare_only);
+			send_prog_page(host, 3, host->spare_only);
+		}
+
+		break;
+
+	case NAND_CMD_ERASE1:
+		useirq = false;
+		break;
+	}
+
+	/* Write out the command to the device. */
+	send_cmd(host, command, useirq);
+
+	/* Write out column address, if necessary */
+	if (column != -1) {
+		/*
+		 * MXC NANDFC can only perform full page+spare or
+		 * spare-only read/write.  When the upper layers
+		 * layers perform a read/write buf operation,
+		 * we will used the saved column adress to index into
+		 * the full page.
+		 */
+		send_addr(host, 0, page_addr == -1);
+		if (host->pagesize_2k)
+			/* another col addr cycle for 2k page */
+			send_addr(host, 0, false);
+	}
+
+	/* Write out page address, if necessary */
+	if (page_addr != -1) {
+		/* paddr_0 - p_addr_7 */
+		send_addr(host, (page_addr & 0xff), false);
+
+		if (host->pagesize_2k) {
+			send_addr(host, (page_addr >> 8) & 0xFF, false);
+			if (mtd->size >= 0x40000000)
+				send_addr(host, (page_addr >> 16) & 0xff, true);
+		} else {
+			/* One more address cycle for higher density devices */
+			if (mtd->size >= 0x4000000) {
+				/* paddr_8 - paddr_15 */
+				send_addr(host, (page_addr >> 8) & 0xff, false);
+				send_addr(host, (page_addr >> 16) & 0xff, true);
+			} else
+				/* paddr_8 - paddr_15 */
+				send_addr(host, (page_addr >> 8) & 0xff, true);
+		}
+	}
+
+	/* Command post-processing step */
+	switch (command) {
+
+	case NAND_CMD_RESET:
+		break;
+
+	case NAND_CMD_READOOB:
+	case NAND_CMD_READ0:
+		if (host->pagesize_2k) {
+			/* send read confirm command */
+			send_cmd(host, NAND_CMD_READSTART, true);
+			/* read for each AREA */
+			send_read_page(host, 0, host->spare_only);
+			send_read_page(host, 1, host->spare_only);
+			send_read_page(host, 2, host->spare_only);
+			send_read_page(host, 3, host->spare_only);
+		} else
+			send_read_page(host, 0, host->spare_only);
+		break;
+
+	case NAND_CMD_READID:
+		send_read_id(host);
+		break;
+
+	case NAND_CMD_PAGEPROG:
+		break;
+
+	case NAND_CMD_STATUS:
+		break;
+
+	case NAND_CMD_ERASE2:
+		break;
+	}
+}
+
+static int __init mxcnd_probe(struct platform_device *pdev)
+{
+	struct nand_chip *this;
+	struct mtd_info *mtd;
+	struct mxc_nand_platform_data *pdata = pdev->dev.platform_data;
+	struct mxc_nand_host *host;
+	struct resource *res;
+	uint16_t tmp;
+	int err = 0, nr_parts = 0;
+
+	/* Allocate memory for MTD device structure and private data */
+	host = kzalloc(sizeof(struct mxc_nand_host), GFP_KERNEL);
+	if (!host)
+		return -ENOMEM;
+
+	host->dev = &pdev->dev;
+	/* structures must be linked */
+	this = &host->nand;
+	mtd = &host->mtd;
+	mtd->priv = this;
+	mtd->owner = THIS_MODULE;
+
+	/* 50 us command delay time */
+	this->chip_delay = 5;
+
+	this->priv = host;
+	this->dev_ready = mxc_nand_dev_ready;
+	this->cmdfunc = mxc_nand_command;
+	this->select_chip = mxc_nand_select_chip;
+	this->read_byte = mxc_nand_read_byte;
+	this->read_word = mxc_nand_read_word;
+	this->write_buf = mxc_nand_write_buf;
+	this->read_buf = mxc_nand_read_buf;
+	this->verify_buf = mxc_nand_verify_buf;
+
+	host->clk = clk_get(&pdev->dev, "nfc_clk");
+	if (IS_ERR(host->clk))
+		goto eclk;
+
+	clk_enable(host->clk);
+	host->clk_act = 1;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		err = -ENODEV;
+		goto eres;
+	}
+
+	host->regs = ioremap(res->start, res->end - res->start + 1);
+	if (!host->regs) {
+		err = -EIO;
+		goto eres;
+	}
+
+	tmp = readw(host->regs + NFC_CONFIG1);
+	tmp |= NFC_INT_MSK;
+	writew(tmp, host->regs + NFC_CONFIG1);
+
+	init_waitqueue_head(&host->irq_waitq);
+
+	host->irq = platform_get_irq(pdev, 0);
+
+	err = request_irq(host->irq, mxc_nfc_irq, 0, "mxc_nd", host);
+	if (err)
+		goto eirq;
+
+	if (pdata->hw_ecc) {
+		this->ecc.calculate = mxc_nand_calculate_ecc;
+		this->ecc.hwctl = mxc_nand_enable_hwecc;
+		this->ecc.correct = mxc_nand_correct_data;
+		this->ecc.mode = NAND_ECC_HW;
+		this->ecc.size = 512;
+		this->ecc.bytes = 3;
+		this->ecc.layout = &nand_hw_eccoob_8;
+		tmp = readw(host->regs + NFC_CONFIG1);
+		tmp |= NFC_ECC_EN;
+		writew(tmp, host->regs + NFC_CONFIG1);
+	} else {
+		this->ecc.size = 512;
+		this->ecc.bytes = 3;
+		this->ecc.layout = &nand_hw_eccoob_8;
+		this->ecc.mode = NAND_ECC_SOFT;
+		tmp = readw(host->regs + NFC_CONFIG1);
+		tmp &= ~NFC_ECC_EN;
+		writew(tmp, host->regs + NFC_CONFIG1);
+	}
+
+	/* Reset NAND */
+	this->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
+	/* preset operation */
+	/* Unlock the internal RAM Buffer */
+	writew(0x2, host->regs + NFC_CONFIG);
+
+	/* Blocks to be unlocked */
+	writew(0x0, host->regs + NFC_UNLOCKSTART_BLKADDR);
+	writew(0x4000, host->regs + NFC_UNLOCKEND_BLKADDR);
+
+	/* Unlock Block Command for given address range */
+	writew(0x4, host->regs + NFC_WRPROT);
+
+	/* NAND bus width determines access funtions used by upper layer */
+	if (pdata->width == 2) {
+		this->options |= NAND_BUSWIDTH_16;
+		this->ecc.layout = &nand_hw_eccoob_16;
+	}
+
+	host->pagesize_2k = 0;
+
+	/* Scan to find existence of the device */
+	if (nand_scan(mtd, 1)) {
+		DEBUG(MTD_DEBUG_LEVEL0,
+		      "MXC_ND: Unable to find any NAND device.\n");
+		err = -ENXIO;
+		goto escan;
+	}
+
+	/* Register the partitions */
+#ifdef CONFIG_MTD_PARTITIONS
+	nr_parts =
+	    parse_mtd_partitions(mtd, part_probes, &host->parts, 0);
+	if (nr_parts > 0)
+		add_mtd_partitions(mtd, host->parts, nr_parts);
+	else
+#endif
+	{
+		pr_info("Registering %s as whole device\n", mtd->name);
+		add_mtd_device(mtd);
+	}
+
+	platform_set_drvdata(pdev, host);
+
+	return 0;
+
+escan:
+	free_irq(host->irq, NULL);
+eirq:
+	iounmap(host->regs);
+eres:
+	clk_put(host->clk);
+eclk:
+	kfree(host);
+
+	return err;
+}
+
+static int __devexit mxcnd_remove(struct platform_device *pdev)
+{
+	struct mxc_nand_host *host = platform_get_drvdata(pdev);
+
+	clk_put(host->clk);
+
+	platform_set_drvdata(pdev, NULL);
+
+	nand_release(&host->mtd);
+	free_irq(host->irq, NULL);
+	iounmap(host->regs);
+	kfree(host);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct mtd_info *info = platform_get_drvdata(pdev);
+	int ret = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND suspend\n");
+	if (info)
+		ret = info->suspend(info);
+
+	/* Disable the NFC clock */
+	clk_disable(nfc_clk);	/* FIXME */
+
+	return ret;
+}
+
+static int mxcnd_resume(struct platform_device *pdev)
+{
+	struct mtd_info *info = platform_get_drvdata(pdev);
+	int ret = 0;
+
+	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND resume\n");
+	/* Enable the NFC clock */
+	clk_enable(nfc_clk);	/* FIXME */
+
+	if (info)
+		info->resume(info);
+
+	return ret;
+}
+
+#else
+# define mxcnd_suspend   NULL
+# define mxcnd_resume    NULL
+#endif				/* CONFIG_PM */
+
+static struct platform_driver mxcnd_driver = {
+	.driver = {
+		   .name = DRIVER_NAME,
+		   },
+	.remove = __exit_p(mxcnd_remove),
+	.suspend = mxcnd_suspend,
+	.resume = mxcnd_resume,
+};
+
+static int __init mxc_nd_init(void)
+{
+	/* Register the device driver structure. */
+	pr_info("MXC MTD nand Driver\n");
+	if (platform_driver_probe(&mxcnd_driver, mxcnd_probe) != 0) {
+		printk(KERN_ERR "Driver register failed for mxcnd_driver\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void __exit mxc_nd_cleanup(void)
+{
+	/* Unregister the device structure */
+	platform_driver_unregister(&mxcnd_driver);
+}
+
+module_init(mxc_nd_init);
+module_exit(mxc_nd_cleanup);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("MXC NAND MTD driver");
+MODULE_LICENSE("GPL");