Patchwork [06/11] mtd: Add MPC5121 NAND Flash Controller driver

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Submitter Anatolij Gustschin
Date Jan. 19, 2010, 8:24 p.m.
Message ID <1263932653-3634-7-git-send-email-agust@denx.de>
Download mbox | patch
Permalink /patch/43223/
State New
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Comments

Anatolij Gustschin - Jan. 19, 2010, 8:24 p.m.
From: Piotr Ziecik <kosmo@semihalf.com>

Adds NAND Flash Controller driver for MPC5121 Revision 2.
All device features, except hardware ECC and power management,
are supported.

Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: <linux-mtd@lists.infradead.org>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: John Rigby <jcrigby@gmail.com>
---
 arch/powerpc/platforms/512x/mpc512x_shared.c |    1 +
 drivers/mtd/nand/Kconfig                     |    7 +
 drivers/mtd/nand/Makefile                    |    1 +
 drivers/mtd/nand/mpc5121_nfc.c               |  916 ++++++++++++++++++++++++++
 4 files changed, 925 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/nand/mpc5121_nfc.c
Wolfram Sang - Jan. 20, 2010, 10:49 a.m.
On Tue, Jan 19, 2010 at 09:24:08PM +0100, Anatolij Gustschin wrote:
> From: Piotr Ziecik <kosmo@semihalf.com>
> 
> Adds NAND Flash Controller driver for MPC5121 Revision 2.
> All device features, except hardware ECC and power management,
> are supported.
> 
> Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
> Signed-off-by: Wolfgang Denk <wd@denx.de>
> Signed-off-by: Anatolij Gustschin <agust@denx.de>
> Cc: <linux-mtd@lists.infradead.org>
> Cc: Grant Likely <grant.likely@secretlab.ca>
> Cc: John Rigby <jcrigby@gmail.com>
> ---

Please include a logfile with changes since the last version. This really
helps.

> +static int __init mpc5121_nfc_probe(struct of_device *op,
> +					const struct of_device_id *match)

[...]

> +{
> +	/* Support external chip-select logic on ADS5121 board */
> +	rootnode = of_find_node_by_path("/");
> +	if (of_device_is_compatible(rootnode, "fsl,mpc5121ads")) {
> +		retval = ads5121_chipselect_init(mtd);
> +		if (retval) {
> +			dev_err(dev, "Chipselect init error!\n");
> +			of_node_put(rootnode);
> +			return retval;
> +		}
> +
> +		chip->select_chip = ads5121_select_chip;
> +	}
> +	of_node_put(rootnode);

If we have to live with the platform-stuff being in the driver, maybe a table
having the compatible-string and an init-function pointer per entry will make
it scale better with the number of boards?

Regards,

   Wolfram

Patch

diff --git a/arch/powerpc/platforms/512x/mpc512x_shared.c b/arch/powerpc/platforms/512x/mpc512x_shared.c
index 8a0d577..38d49ad 100644
--- a/arch/powerpc/platforms/512x/mpc512x_shared.c
+++ b/arch/powerpc/platforms/512x/mpc512x_shared.c
@@ -83,6 +83,7 @@  void __init mpc512x_init_IRQ(void)
 static struct of_device_id __initdata of_bus_ids[] = {
 	{ .compatible = "fsl,mpc5121-immr", },
 	{ .compatible = "fsl,mpc5121-localbus", },
+	{ .compatible = "fsl,mpc5121-nfc", },
 	{},
 };
 
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 677cd53..099f002 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -442,6 +442,13 @@  config MTD_NAND_FSL_UPM
 	  Enables support for NAND Flash chips wired onto Freescale PowerPC
 	  processor localbus with User-Programmable Machine support.
 
+config MTD_NAND_MPC5121_NFC
+	tristate "MPC5121 built-in NAND Flash Controller support"
+	depends on PPC_MPC512x
+	help
+	  This enables the driver for the NAND flash controller on the
+	  MPC5121 SoC.
+
 config MTD_NAND_MXC
 	tristate "MXC NAND support"
 	depends on ARCH_MX2 || ARCH_MX3
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 1407bd1..d4ddf05 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -42,5 +42,6 @@  obj-$(CONFIG_MTD_NAND_TXX9NDFMC)	+= txx9ndfmc.o
 obj-$(CONFIG_MTD_NAND_W90P910)		+= w90p910_nand.o
 obj-$(CONFIG_MTD_NAND_NOMADIK)		+= nomadik_nand.o
 obj-$(CONFIG_MTD_NAND_BCM_UMI)		+= bcm_umi_nand.o nand_bcm_umi.o
+obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
 
 nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/mpc5121_nfc.c b/drivers/mtd/nand/mpc5121_nfc.c
new file mode 100644
index 0000000..2980eb1
--- /dev/null
+++ b/drivers/mtd/nand/mpc5121_nfc.c
@@ -0,0 +1,916 @@ 
+/*
+ * Copyright 2004-2008 Freescale Semiconductor, Inc.
+ * Copyright 2009 Semihalf.
+ *
+ * Approved as OSADL project by a majority of OSADL members and funded
+ * by OSADL membership fees in 2009;  for details see www.osadl.org.
+ *
+ * Based on original driver from Freescale Semiconductor
+ * written by John Rigby <jrigby@freescale.com> on basis
+ * of drivers/mtd/nand/mxc_nand.c. Reworked and extended
+ * Piotr Ziecik <kosmo@semihalf.com>.
+ *
+ * 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/module.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+
+#include <asm/mpc5xxx.h>
+
+/* Addresses for NFC MAIN RAM BUFFER areas */
+#define NFC_MAIN_AREA(n)	((n) *  0x200)
+
+/* Addresses for NFC SPARE BUFFER areas */
+#define NFC_SPARE_BUFFERS	8
+#define NFC_SPARE_LEN		0x40
+#define NFC_SPARE_AREA(n)	(0x1000 + ((n) * NFC_SPARE_LEN))
+
+/* MPC5121 NFC registers */
+#define NFC_BUF_ADDR		0x1E04
+#define NFC_FLASH_ADDR		0x1E06
+#define NFC_FLASH_CMD		0x1E08
+#define NFC_CONFIG		0x1E0A
+#define NFC_ECC_STATUS1		0x1E0C
+#define NFC_ECC_STATUS2		0x1E0E
+#define NFC_SPAS		0x1E10
+#define NFC_WRPROT		0x1E12
+#define NFC_NF_WRPRST		0x1E18
+#define NFC_CONFIG1		0x1E1A
+#define NFC_CONFIG2		0x1E1C
+#define NFC_UNLOCKSTART_BLK0	0x1E20
+#define NFC_UNLOCKEND_BLK0	0x1E22
+#define NFC_UNLOCKSTART_BLK1	0x1E24
+#define NFC_UNLOCKEND_BLK1	0x1E26
+#define NFC_UNLOCKSTART_BLK2	0x1E28
+#define NFC_UNLOCKEND_BLK2	0x1E2A
+#define NFC_UNLOCKSTART_BLK3	0x1E2C
+#define NFC_UNLOCKEND_BLK3	0x1E2E
+
+/* Bit Definitions: NFC_BUF_ADDR */
+#define NFC_RBA_MASK		(7 << 0)
+#define NFC_ACTIVE_CS_SHIFT	5
+#define NFC_ACTIVE_CS_MASK	(3 << NFC_ACTIVE_CS_SHIFT)
+
+/* Bit Definitions: NFC_CONFIG */
+#define NFC_BLS_UNLOCKED	(1 << 1)
+
+/* Bit Definitions: NFC_CONFIG1 */
+#define NFC_ECC_4BIT		(1 << 0)
+#define NFC_FULL_PAGE_DMA	(1 << 1)
+#define NFC_SPARE_ONLY		(1 << 2)
+#define NFC_ECC_ENABLE		(1 << 3)
+#define NFC_INT_MASK		(1 << 4)
+#define NFC_BIG_ENDIAN		(1 << 5)
+#define NFC_RESET		(1 << 6)
+#define NFC_CE			(1 << 7)
+#define NFC_ONE_CYCLE		(1 << 8)
+#define NFC_PPB_32		(0 << 9)
+#define NFC_PPB_64		(1 << 9)
+#define NFC_PPB_128		(2 << 9)
+#define NFC_PPB_256		(3 << 9)
+#define NFC_PPB_MASK		(3 << 9)
+#define NFC_FULL_PAGE_INT	(1 << 11)
+
+/* Bit Definitions: NFC_CONFIG2 */
+#define NFC_COMMAND		(1 << 0)
+#define NFC_ADDRESS		(1 << 1)
+#define NFC_INPUT		(1 << 2)
+#define NFC_OUTPUT		(1 << 3)
+#define NFC_ID			(1 << 4)
+#define NFC_STATUS		(1 << 5)
+#define NFC_CMD_FAIL		(1 << 15)
+#define NFC_INT			(1 << 15)
+
+/* Bit Definitions: NFC_WRPROT */
+#define NFC_WPC_LOCK_TIGHT	(1 << 0)
+#define NFC_WPC_LOCK		(1 << 1)
+#define NFC_WPC_UNLOCK		(1 << 2)
+
+#define	DRV_NAME		"mpc5121_nfc"
+
+/* Timeouts */
+#define NFC_RESET_TIMEOUT	1000		/* 1 ms */
+#define NFC_TIMEOUT		(HZ / 10)	/* 1/10 s */
+
+struct mpc5121_nfc_prv {
+	struct mtd_info		mtd;
+	struct nand_chip	chip;
+	int			irq;
+	void __iomem		*regs;
+	struct clk		*clk;
+	wait_queue_head_t	irq_waitq;
+	uint			column;
+	int			spareonly;
+	void __iomem		*csreg;
+	struct device		*dev;
+};
+
+static void mpc5121_nfc_done(struct mtd_info *mtd);
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *mpc5121_nfc_pprobes[] = { "cmdlinepart", NULL };
+#endif
+
+/* Read NFC register */
+static inline u16 nfc_read(struct mtd_info *mtd, uint reg)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+
+	return in_be16(prv->regs + reg);
+}
+
+/* Write NFC register */
+static inline void nfc_write(struct mtd_info *mtd, uint reg, u16 val)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+
+	out_be16(prv->regs + reg, val);
+}
+
+/* Set bits in NFC register */
+static inline void nfc_set(struct mtd_info *mtd, uint reg, u16 bits)
+{
+	nfc_write(mtd, reg, nfc_read(mtd, reg) | bits);
+}
+
+/* Clear bits in NFC register */
+static inline void nfc_clear(struct mtd_info *mtd, uint reg, u16 bits)
+{
+	nfc_write(mtd, reg, nfc_read(mtd, reg) & ~bits);
+}
+
+/* Invoke address cycle */
+static inline void mpc5121_nfc_send_addr(struct mtd_info *mtd, u16 addr)
+{
+	nfc_write(mtd, NFC_FLASH_ADDR, addr);
+	nfc_write(mtd, NFC_CONFIG2, NFC_ADDRESS);
+	mpc5121_nfc_done(mtd);
+}
+
+/* Invoke command cycle */
+static inline void mpc5121_nfc_send_cmd(struct mtd_info *mtd, u16 cmd)
+{
+	nfc_write(mtd, NFC_FLASH_CMD, cmd);
+	nfc_write(mtd, NFC_CONFIG2, NFC_COMMAND);
+	mpc5121_nfc_done(mtd);
+}
+
+/* Send data from NFC buffers to NAND flash */
+static inline void mpc5121_nfc_send_prog_page(struct mtd_info *mtd)
+{
+	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
+	nfc_write(mtd, NFC_CONFIG2, NFC_INPUT);
+	mpc5121_nfc_done(mtd);
+}
+
+/* Receive data from NAND flash */
+static inline void mpc5121_nfc_send_read_page(struct mtd_info *mtd)
+{
+	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
+	nfc_write(mtd, NFC_CONFIG2, NFC_OUTPUT);
+	mpc5121_nfc_done(mtd);
+}
+
+/* Receive ID from NAND flash */
+static inline void mpc5121_nfc_send_read_id(struct mtd_info *mtd)
+{
+	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
+	nfc_write(mtd, NFC_CONFIG2, NFC_ID);
+	mpc5121_nfc_done(mtd);
+}
+
+/* Receive status from NAND flash */
+static inline void mpc5121_nfc_send_read_status(struct mtd_info *mtd)
+{
+	nfc_clear(mtd, NFC_BUF_ADDR, NFC_RBA_MASK);
+	nfc_write(mtd, NFC_CONFIG2, NFC_STATUS);
+	mpc5121_nfc_done(mtd);
+}
+
+/* NFC interrupt handler */
+static irqreturn_t mpc5121_nfc_irq(int irq, void *data)
+{
+	struct mtd_info *mtd = data;
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+
+	nfc_set(mtd, NFC_CONFIG1, NFC_INT_MASK);
+	wake_up(&prv->irq_waitq);
+
+	return IRQ_HANDLED;
+}
+
+/* Wait for operation complete */
+static void mpc5121_nfc_done(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+	int rv;
+
+	if ((nfc_read(mtd, NFC_CONFIG2) & NFC_INT) == 0) {
+		nfc_clear(mtd, NFC_CONFIG1, NFC_INT_MASK);
+		rv = wait_event_timeout(prv->irq_waitq,
+			(nfc_read(mtd, NFC_CONFIG2) & NFC_INT), NFC_TIMEOUT);
+
+		if (!rv)
+			dev_warn(prv->dev,
+				"Timeout while waiting for interrupt.\n");
+	}
+
+	nfc_clear(mtd, NFC_CONFIG2, NFC_INT);
+}
+
+/* Do address cycle(s) */
+static void mpc5121_nfc_addr_cycle(struct mtd_info *mtd, int column, int page)
+{
+	struct nand_chip *chip = mtd->priv;
+	u32 pagemask = chip->pagemask;
+
+	if (column != -1) {
+		mpc5121_nfc_send_addr(mtd, column);
+		if (mtd->writesize > 512)
+			mpc5121_nfc_send_addr(mtd, column >> 8);
+	}
+
+	if (page != -1) {
+		do {
+			mpc5121_nfc_send_addr(mtd, page & 0xFF);
+			page >>= 8;
+			pagemask >>= 8;
+		} while (pagemask);
+	}
+}
+
+/* Control chip select signals */
+static void mpc5121_nfc_select_chip(struct mtd_info *mtd, int chip)
+{
+	if (chip < 0) {
+		nfc_clear(mtd, NFC_CONFIG1, NFC_CE);
+		return;
+	}
+
+	nfc_clear(mtd, NFC_BUF_ADDR, NFC_ACTIVE_CS_MASK);
+	nfc_set(mtd, NFC_BUF_ADDR, (chip << NFC_ACTIVE_CS_SHIFT) &
+							NFC_ACTIVE_CS_MASK);
+	nfc_set(mtd, NFC_CONFIG1, NFC_CE);
+}
+
+/* Init external chip select logic on ADS5121 board */
+static int ads5121_chipselect_init(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+	struct device_node *dn;
+
+	dn = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld");
+	if (dn) {
+		prv->csreg = of_iomap(dn, 0);
+		of_node_put(dn);
+		if (!prv->csreg)
+			return -ENOMEM;
+
+		/* CPLD Register 9 controls NAND /CE Lines */
+		prv->csreg += 9;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/* Control chips select signal on ADS5121 board */
+static void ads5121_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct mpc5121_nfc_prv *prv = nand->priv;
+	u8 v;
+
+	v = in_8(prv->csreg);
+	v |= 0x0F;
+
+	if (chip >= 0) {
+		mpc5121_nfc_select_chip(mtd, 0);
+		v &= ~(1 << chip);
+	} else
+		mpc5121_nfc_select_chip(mtd, -1);
+
+	out_8(prv->csreg, v);
+}
+
+/* Read NAND Ready/Busy signal */
+static int mpc5121_nfc_dev_ready(struct mtd_info *mtd)
+{
+	/*
+	 * NFC handles ready/busy signal internally. Therefore, this function
+	 * always returns status as ready.
+	 */
+	return 1;
+}
+
+/* Write command to NAND flash */
+static void mpc5121_nfc_command(struct mtd_info *mtd, unsigned command,
+							int column, int page)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+
+	prv->column = (column >= 0) ? column : 0;
+	prv->spareonly = 0;
+
+	switch (command) {
+	case NAND_CMD_PAGEPROG:
+		mpc5121_nfc_send_prog_page(mtd);
+		break;
+	/*
+	 * NFC does not support sub-page reads and writes,
+	 * so emulate them using full page transfers.
+	 */
+	case NAND_CMD_READ0:
+		column = 0;
+		break;
+
+	case NAND_CMD_READ1:
+		prv->column += 256;
+		command = NAND_CMD_READ0;
+		column = 0;
+		break;
+
+	case NAND_CMD_READOOB:
+		prv->spareonly = 1;
+		command = NAND_CMD_READ0;
+		column = 0;
+		break;
+
+	case NAND_CMD_SEQIN:
+		mpc5121_nfc_command(mtd, NAND_CMD_READ0, column, page);
+		column = 0;
+		break;
+
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_READID:
+	case NAND_CMD_STATUS:
+		break;
+
+	default:
+		return;
+	}
+
+	mpc5121_nfc_send_cmd(mtd, command);
+	mpc5121_nfc_addr_cycle(mtd, column, page);
+
+	switch (command) {
+	case NAND_CMD_READ0:
+		if (mtd->writesize > 512)
+			mpc5121_nfc_send_cmd(mtd, NAND_CMD_READSTART);
+		mpc5121_nfc_send_read_page(mtd);
+		break;
+
+	case NAND_CMD_READID:
+		mpc5121_nfc_send_read_id(mtd);
+		break;
+
+	case NAND_CMD_STATUS:
+		mpc5121_nfc_send_read_status(mtd);
+		if (chip->options & NAND_BUSWIDTH_16)
+			prv->column = 1;
+		else
+			prv->column = 0;
+		break;
+	}
+}
+
+/* Copy data from/to NFC spare buffers. */
+static void mpc5121_nfc_copy_spare(struct mtd_info *mtd, uint offset,
+						u8 *buffer, uint size, int wr)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct mpc5121_nfc_prv *prv = nand->priv;
+	uint o, s, sbsize, blksize;
+
+	/*
+	 * NAND spare area is available through NFC spare buffers.
+	 * The NFC divides spare area into (page_size / 512) chunks.
+	 * Each chunk is placed into separate spare memory area, using
+	 * first (spare_size / num_of_chunks) bytes of the buffer.
+	 *
+	 * For NAND device in which the spare area is not divided fully
+	 * by the number of chunks, number of used bytes in each spare
+	 * buffer is rounded down to the nearest even number of bytes,
+	 * and all remaining bytes are added to the last used spare area.
+	 *
+	 * For more information read section 26.6.10 of MPC5121e
+	 * Microcontroller Reference Manual, Rev. 3.
+	 */
+
+	/* Calculate number of valid bytes in each spare buffer */
+	sbsize = (mtd->oobsize / (mtd->writesize / 512)) & ~1;
+
+	while (size) {
+		/* Calculate spare buffer number */
+		s = offset / sbsize;
+		if (s > NFC_SPARE_BUFFERS - 1)
+			s = NFC_SPARE_BUFFERS - 1;
+
+		/*
+		 * Calculate offset to requested data block in selected spare
+		 * buffer and its size.
+		 */
+		o = offset - (s * sbsize);
+		blksize = min(sbsize - o, size);
+
+		if (wr)
+			memcpy_toio(prv->regs + NFC_SPARE_AREA(s) + o,
+							buffer, blksize);
+		else
+			memcpy_fromio(buffer,
+				prv->regs + NFC_SPARE_AREA(s) + o, blksize);
+
+		buffer += blksize;
+		offset += blksize;
+		size -= blksize;
+	};
+}
+
+/* Copy data from/to NFC main and spare buffers */
+static void mpc5121_nfc_buf_copy(struct mtd_info *mtd, u_char *buf, int len,
+									int wr)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+	uint c = prv->column;
+	uint l;
+
+	/* Handle spare area access */
+	if (prv->spareonly || c >= mtd->writesize) {
+		/* Calculate offset from beginning of spare area */
+		if (c >= mtd->writesize)
+			c -= mtd->writesize;
+
+		prv->column += len;
+		mpc5121_nfc_copy_spare(mtd, c, buf, len, wr);
+		return;
+	}
+
+	/*
+	 * Handle main area access - limit copy length to prevent
+	 * crossing main/spare boundary.
+	 */
+	l = min((uint)len, mtd->writesize - c);
+	prv->column += l;
+
+	if (wr)
+		memcpy_toio(prv->regs + NFC_MAIN_AREA(0) + c, buf, l);
+	else
+		memcpy_fromio(buf, prv->regs + NFC_MAIN_AREA(0) + c, l);
+
+	/* Handle crossing main/spare boundary */
+	if (l != len) {
+		buf += l;
+		len -= l;
+		mpc5121_nfc_buf_copy(mtd, buf, len, wr);
+	}
+}
+
+/* Read data from NFC buffers */
+static void mpc5121_nfc_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	mpc5121_nfc_buf_copy(mtd, buf, len, 0);
+}
+
+/* Write data to NFC buffers */
+static void mpc5121_nfc_write_buf(struct mtd_info *mtd,
+						const u_char *buf, int len)
+{
+	mpc5121_nfc_buf_copy(mtd, (u_char *)buf, len, 1);
+}
+
+/* Compare buffer with NAND flash */
+static int mpc5121_nfc_verify_buf(struct mtd_info *mtd,
+						const u_char *buf, int len)
+{
+	u_char tmp[256];
+	uint bsize;
+
+	while (len) {
+		bsize = min(len, 256);
+		mpc5121_nfc_read_buf(mtd, tmp, bsize);
+
+		if (memcmp(buf, tmp, bsize))
+			return 1;
+
+		buf += bsize;
+		len -= bsize;
+	}
+
+	return 0;
+}
+
+/* Read byte from NFC buffers */
+static u8 mpc5121_nfc_read_byte(struct mtd_info *mtd)
+{
+	u8 tmp;
+
+	mpc5121_nfc_read_buf(mtd, &tmp, sizeof(tmp));
+
+	return tmp;
+}
+
+/* Read word from NFC buffers */
+static u16 mpc5121_nfc_read_word(struct mtd_info *mtd)
+{
+	u16 tmp;
+
+	mpc5121_nfc_read_buf(mtd, (u_char *)&tmp, sizeof(tmp));
+
+	return tmp;
+}
+
+/*
+ * Read NFC configuration from Reset Config Word
+ *
+ * NFC is configured during reset in basis of information stored
+ * in Reset Config Word. There is no other way to set NAND block
+ * size, spare size and bus width.
+ */
+static int mpc5121_nfc_read_hw_config(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+	struct mpc512x_reset_module *rm;
+	struct device_node *rmnode;
+	uint rcw_pagesize = 0;
+	uint rcw_sparesize = 0;
+	uint rcw_width;
+	uint rcwh;
+	uint romloc, ps;
+
+	rmnode = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-reset");
+	if (!rmnode) {
+		dev_err(prv->dev, "Missing 'fsl,mpc5121-reset' "
+					"node in device tree!\n");
+		return -ENODEV;
+	}
+
+	rm = of_iomap(rmnode, 0);
+	if (!rm) {
+		dev_err(prv->dev, "Error mapping reset module node!\n");
+		return -EBUSY;
+	}
+
+	rcwh = in_be32(&rm->rcwhr);
+
+	/* Bit 6: NFC bus width */
+	rcw_width = ((rcwh >> 6) & 0x1) ? 2 : 1;
+
+	/* Bit 7: NFC Page/Spare size */
+	ps = (rcwh >> 7) & 0x1;
+
+	/* Bits [22:21]: ROM Location */
+	romloc = (rcwh >> 21) & 0x3;
+
+	/* Decode RCW bits */
+	switch ((ps << 2) | romloc) {
+	case 0x00:
+	case 0x01:
+		rcw_pagesize = 512;
+		rcw_sparesize = 16;
+		break;
+	case 0x02:
+	case 0x03:
+		rcw_pagesize = 4096;
+		rcw_sparesize = 128;
+		break;
+	case 0x04:
+	case 0x05:
+		rcw_pagesize = 2048;
+		rcw_sparesize = 64;
+		break;
+	case 0x06:
+	case 0x07:
+		rcw_pagesize = 4096;
+		rcw_sparesize = 218;
+		break;
+	}
+
+	mtd->writesize = rcw_pagesize;
+	mtd->oobsize = rcw_sparesize;
+	if (rcw_width == 2)
+		chip->options |= NAND_BUSWIDTH_16;
+
+	dev_notice(prv->dev, "Configured for "
+				"%u-bit NAND, page size %u "
+				"with %u spare.\n",
+				rcw_width * 8, rcw_pagesize,
+				rcw_sparesize);
+	iounmap(rm);
+	of_node_put(rmnode);
+	return 0;
+}
+
+/* Free driver resources */
+static void mpc5121_nfc_free(struct device *dev, struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+
+	if (prv->clk) {
+		clk_disable(prv->clk);
+		clk_put(prv->clk);
+	}
+
+	if (prv->csreg)
+		iounmap(prv->csreg);
+}
+
+static int __init mpc5121_nfc_probe(struct of_device *op,
+					const struct of_device_id *match)
+{
+	struct device_node *rootnode, *dn = op->node;
+	struct device *dev = &op->dev;
+	struct mpc5121_nfc_prv *prv;
+	struct resource res;
+	struct mtd_info *mtd;
+#ifdef CONFIG_MTD_PARTITIONS
+	struct mtd_partition *parts;
+#endif
+	struct nand_chip *chip;
+	unsigned long regs_paddr, regs_size;
+	const uint *chips_no;
+	int resettime = 0;
+	int retval = 0;
+	int rev, len;
+
+	/*
+	 * Check SoC revision. This driver supports only NFC
+	 * in MPC5121 revision 2.
+	 */
+	rev = (mfspr(SPRN_SVR) >> 4) & 0xF;
+	if (rev != 2) {
+		dev_err(dev, "SoC revision %u is not supported!\n", rev);
+		return -ENXIO;
+	}
+
+	prv = devm_kzalloc(dev, sizeof(*prv), GFP_KERNEL);
+	if (!prv) {
+		dev_err(dev, "Memory exhausted!\n");
+		return -ENOMEM;
+	}
+
+	mtd = &prv->mtd;
+	chip = &prv->chip;
+
+	mtd->priv = chip;
+	chip->priv = prv;
+	prv->dev = dev;
+
+	/* Read NFC configuration from Reset Config Word */
+	retval = mpc5121_nfc_read_hw_config(mtd);
+	if (retval) {
+		dev_err(dev, "Unable to read NFC config!\n");
+		return retval;
+	}
+
+	prv->irq = irq_of_parse_and_map(dn, 0);
+	if (prv->irq == NO_IRQ) {
+		dev_err(dev, "Error mapping IRQ!\n");
+		return -EINVAL;
+	}
+
+	retval = of_address_to_resource(dn, 0, &res);
+	if (retval) {
+		dev_err(dev, "Error parsing memory region!\n");
+		return retval;
+	}
+
+	chips_no = of_get_property(dn, "chips", &len);
+	if (!chips_no || len != sizeof(*chips_no)) {
+		dev_err(dev, "Invalid/missing 'chips' property!\n");
+		return -EINVAL;
+	}
+
+	regs_paddr = res.start;
+	regs_size = res.end - res.start + 1;
+
+	if (!devm_request_mem_region(dev, regs_paddr, regs_size, DRV_NAME)) {
+		dev_err(dev, "Error requesting memory region!\n");
+		return -EBUSY;
+	}
+
+	prv->regs = devm_ioremap(dev, regs_paddr, regs_size);
+	if (!prv->regs) {
+		dev_err(dev, "Error mapping memory region!\n");
+		return -ENOMEM;
+	}
+
+	mtd->name = "MPC5121 NAND";
+	chip->dev_ready = mpc5121_nfc_dev_ready;
+	chip->cmdfunc = mpc5121_nfc_command;
+	chip->read_byte = mpc5121_nfc_read_byte;
+	chip->read_word = mpc5121_nfc_read_word;
+	chip->read_buf = mpc5121_nfc_read_buf;
+	chip->write_buf = mpc5121_nfc_write_buf;
+	chip->verify_buf = mpc5121_nfc_verify_buf;
+	chip->select_chip = mpc5121_nfc_select_chip;
+	chip->options = NAND_NO_AUTOINCR | NAND_USE_FLASH_BBT;
+	chip->ecc.mode = NAND_ECC_SOFT;
+
+	/* Support external chip-select logic on ADS5121 board */
+	rootnode = of_find_node_by_path("/");
+	if (of_device_is_compatible(rootnode, "fsl,mpc5121ads")) {
+		retval = ads5121_chipselect_init(mtd);
+		if (retval) {
+			dev_err(dev, "Chipselect init error!\n");
+			of_node_put(rootnode);
+			return retval;
+		}
+
+		chip->select_chip = ads5121_select_chip;
+	}
+	of_node_put(rootnode);
+
+	/* Enable NFC clock */
+	prv->clk = clk_get(dev, "nfc_clk");
+	if (!prv->clk) {
+		dev_err(dev, "Unable to acquire NFC clock!\n");
+		retval = -ENODEV;
+		goto error;
+	}
+
+	clk_enable(prv->clk);
+
+	/* Reset NAND Flash controller */
+	nfc_set(mtd, NFC_CONFIG1, NFC_RESET);
+	while (nfc_read(mtd, NFC_CONFIG1) & NFC_RESET) {
+		if (resettime++ >= NFC_RESET_TIMEOUT) {
+			dev_err(dev, "Timeout while resetting NFC!\n");
+			retval = -EINVAL;
+			goto error;
+		}
+
+		udelay(1);
+	}
+
+	/* Enable write to NFC memory */
+	nfc_write(mtd, NFC_CONFIG, NFC_BLS_UNLOCKED);
+
+	/* Enable write to all NAND pages */
+	nfc_write(mtd, NFC_UNLOCKSTART_BLK0, 0x0000);
+	nfc_write(mtd, NFC_UNLOCKEND_BLK0, 0xFFFF);
+	nfc_write(mtd, NFC_WRPROT, NFC_WPC_UNLOCK);
+
+	/*
+	 * Setup NFC:
+	 *	- Big Endian transfers,
+	 *	- Interrupt after full page read/write.
+	 */
+	nfc_write(mtd, NFC_CONFIG1, NFC_BIG_ENDIAN | NFC_INT_MASK |
+							NFC_FULL_PAGE_INT);
+
+	/* Set spare area size */
+	nfc_write(mtd, NFC_SPAS, mtd->oobsize >> 1);
+
+	init_waitqueue_head(&prv->irq_waitq);
+	retval = devm_request_irq(dev, prv->irq, &mpc5121_nfc_irq, 0, DRV_NAME,
+									mtd);
+	if (retval) {
+		dev_err(dev, "Error requesting IRQ!\n");
+		goto error;
+	}
+
+	/* Detect NAND chips */
+	if (nand_scan(mtd, *chips_no)) {
+		dev_err(dev, "NAND Flash not found !\n");
+		devm_free_irq(dev, prv->irq, mtd);
+		retval = -ENXIO;
+		goto error;
+	}
+
+	/* Set erase block size */
+	switch (mtd->erasesize / mtd->writesize) {
+	case 32:
+		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_32);
+		break;
+
+	case 64:
+		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_64);
+		break;
+
+	case 128:
+		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_128);
+		break;
+
+	case 256:
+		nfc_set(mtd, NFC_CONFIG1, NFC_PPB_256);
+		break;
+
+	default:
+		dev_err(dev, "Unsupported NAND flash!\n");
+		devm_free_irq(dev, prv->irq, mtd);
+		retval = -ENXIO;
+		goto error;
+	}
+
+	dev_set_drvdata(dev, mtd);
+
+	/* Register device in MTD */
+#ifdef CONFIG_MTD_PARTITIONS
+	retval = parse_mtd_partitions(mtd, mpc5121_nfc_pprobes, &parts, 0);
+#ifdef CONFIG_MTD_OF_PARTS
+	if (retval == 0)
+		retval = of_mtd_parse_partitions(dev, dn, &parts);
+#endif
+	if (retval < 0) {
+		dev_err(dev, "Error parsing MTD partitions!\n");
+		devm_free_irq(dev, prv->irq, mtd);
+		retval = -EINVAL;
+		goto error;
+	}
+
+	if (retval > 0)
+		retval = add_mtd_partitions(mtd, parts, retval);
+	else
+#endif
+		retval = add_mtd_device(mtd);
+
+	if (retval) {
+		dev_err(dev, "Error adding MTD device!\n");
+		devm_free_irq(dev, prv->irq, mtd);
+		goto error;
+	}
+
+	return 0;
+error:
+	mpc5121_nfc_free(dev, mtd);
+	return retval;
+}
+
+static int __exit mpc5121_nfc_remove(struct of_device *op)
+{
+	struct device *dev = &op->dev;
+	struct mtd_info *mtd = dev_get_drvdata(dev);
+	struct nand_chip *chip = mtd->priv;
+	struct mpc5121_nfc_prv *prv = chip->priv;
+
+	nand_release(mtd);
+	devm_free_irq(dev, prv->irq, mtd);
+	mpc5121_nfc_free(dev, mtd);
+
+	return 0;
+}
+
+static struct of_device_id mpc5121_nfc_match[] = {
+	{ .compatible = "fsl,mpc5121-nfc", },
+	{},
+};
+
+static struct of_platform_driver mpc5121_nfc_driver = {
+	.match_table	= mpc5121_nfc_match,
+	.probe		= mpc5121_nfc_probe,
+	.remove		= __exit_p(mpc5121_nfc_remove),
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init mpc5121_nfc_init(void)
+{
+	return of_register_platform_driver(&mpc5121_nfc_driver);
+}
+
+module_init(mpc5121_nfc_init);
+
+static void __exit mpc5121_nfc_cleanup(void)
+{
+	of_unregister_platform_driver(&mpc5121_nfc_driver);
+}
+
+module_exit(mpc5121_nfc_cleanup);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("MPC5121 NAND MTD driver");
+MODULE_LICENSE("GPL");