[MTD] [NAND] support for pxa3xx

This is preliminary since:

1. It supports only _one_ chip select at the moment. As there is no
   existing platforms available using two chip selects of the NAND
   controller, it shall really not include code for supporting the
   2nd chip select for now, as such code cannot be verified.

2. It resorts to the default and simpliest memory based badblock
   table

3. Only limited types of nand flash are currently supported. Most
   PXA3xx processors come with on-chip NAND flash dies, so there
   isn't much flexibility for other types of NAND.

4. The NAND controller should be configured to detect the device's
   ID, thus making it difficult to use nand_scan_ident() to assist
   the detection process (though it's not impossible)

TODO: fix all the above limitations of cuz :-)

Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: Sergey Podstavin <spodstavin@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

3 files changed, 1257 insertions, 0 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 959fb86cda0..180fc7be182 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -279,6 +279,13 @@ config MTD_NAND_AT91
 	  Enables support for NAND Flash / Smart Media Card interface
 	  on Atmel AT91 processors.
 
+config MTD_NAND_PXA3xx
+	bool "Support for NAND flash devices on PXA3xx"
+	depends on MTD_NAND && PXA3xx
+	help
+	  This enables the driver for the NAND flash device found on
+	  PXA3xx processors
+
 config MTD_NAND_CM_X270
 	tristate "Support for NAND Flash on CM-X270 modules"
 	depends on MTD_NAND && MACH_ARMCORE
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 80d575eeee9..54a332bda3d 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
 obj-$(CONFIG_MTD_NAND_AT91)		+= at91_nand.o
 obj-$(CONFIG_MTD_NAND_CM_X270)		+= cmx270_nand.o
 obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
+obj-$(CONFIG_MTD_NAND_PXA3xx)		+= pxa3xx_nand.o
 obj-$(CONFIG_MTD_NAND_PLATFORM)		+= plat_nand.o
 obj-$(CONFIG_MTD_ALAUDA)		+= alauda.o
 obj-$(CONFIG_MTD_NAND_PASEMI)		+= pasemi_nand.o
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
new file mode 100644
index 00000000000..138e219c230
--- /dev/null
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -0,0 +1,1249 @@
+/*
+ * drivers/mtd/nand/pxa3xx_nand.c
+ *
+ * Copyright © 2005 Intel Corporation
+ * Copyright © 2006 Marvell International Ltd.
+ *
+ * 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/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/dma.h>
+
+#include <asm/arch/pxa-regs.h>
+#include <asm/arch/pxa3xx_nand.h>
+
+#define	CHIP_DELAY_TIMEOUT	(2 * HZ/10)
+
+/* registers and bit definitions */
+#define NDCR		(0x00) /* Control register */
+#define NDTR0CS0	(0x04) /* Timing Parameter 0 for CS0 */
+#define NDTR1CS0	(0x0C) /* Timing Parameter 1 for CS0 */
+#define NDSR		(0x14) /* Status Register */
+#define NDPCR		(0x18) /* Page Count Register */
+#define NDBDR0		(0x1C) /* Bad Block Register 0 */
+#define NDBDR1		(0x20) /* Bad Block Register 1 */
+#define NDDB		(0x40) /* Data Buffer */
+#define NDCB0		(0x48) /* Command Buffer0 */
+#define NDCB1		(0x4C) /* Command Buffer1 */
+#define NDCB2		(0x50) /* Command Buffer2 */
+
+#define NDCR_SPARE_EN		(0x1 << 31)
+#define NDCR_ECC_EN		(0x1 << 30)
+#define NDCR_DMA_EN		(0x1 << 29)
+#define NDCR_ND_RUN		(0x1 << 28)
+#define NDCR_DWIDTH_C		(0x1 << 27)
+#define NDCR_DWIDTH_M		(0x1 << 26)
+#define NDCR_PAGE_SZ		(0x1 << 24)
+#define NDCR_NCSX		(0x1 << 23)
+#define NDCR_ND_MODE		(0x3 << 21)
+#define NDCR_NAND_MODE   	(0x0)
+#define NDCR_CLR_PG_CNT		(0x1 << 20)
+#define NDCR_CLR_ECC		(0x1 << 19)
+#define NDCR_RD_ID_CNT_MASK	(0x7 << 16)
+#define NDCR_RD_ID_CNT(x)	(((x) << 16) & NDCR_RD_ID_CNT_MASK)
+
+#define NDCR_RA_START		(0x1 << 15)
+#define NDCR_PG_PER_BLK		(0x1 << 14)
+#define NDCR_ND_ARB_EN		(0x1 << 12)
+
+#define NDSR_MASK		(0xfff)
+#define NDSR_RDY		(0x1 << 11)
+#define NDSR_CS0_PAGED		(0x1 << 10)
+#define NDSR_CS1_PAGED		(0x1 << 9)
+#define NDSR_CS0_CMDD		(0x1 << 8)
+#define NDSR_CS1_CMDD		(0x1 << 7)
+#define NDSR_CS0_BBD		(0x1 << 6)
+#define NDSR_CS1_BBD		(0x1 << 5)
+#define NDSR_DBERR		(0x1 << 4)
+#define NDSR_SBERR		(0x1 << 3)
+#define NDSR_WRDREQ		(0x1 << 2)
+#define NDSR_RDDREQ		(0x1 << 1)
+#define NDSR_WRCMDREQ		(0x1)
+
+#define NDCB0_AUTO_RS		(0x1 << 25)
+#define NDCB0_CSEL		(0x1 << 24)
+#define NDCB0_CMD_TYPE_MASK	(0x7 << 21)
+#define NDCB0_CMD_TYPE(x)	(((x) << 21) & NDCB0_CMD_TYPE_MASK)
+#define NDCB0_NC		(0x1 << 20)
+#define NDCB0_DBC		(0x1 << 19)
+#define NDCB0_ADDR_CYC_MASK	(0x7 << 16)
+#define NDCB0_ADDR_CYC(x)	(((x) << 16) & NDCB0_ADDR_CYC_MASK)
+#define NDCB0_CMD2_MASK		(0xff << 8)
+#define NDCB0_CMD1_MASK		(0xff)
+#define NDCB0_ADDR_CYC_SHIFT	(16)
+
+/* dma-able I/O address for the NAND data and commands */
+#define NDCB0_DMA_ADDR		(0x43100048)
+#define NDDB_DMA_ADDR		(0x43100040)
+
+/* macros for registers read/write */
+#define nand_writel(info, off, val)	\
+	__raw_writel((val), (info)->mmio_base + (off))
+
+#define nand_readl(info, off)		\
+	__raw_readl((info)->mmio_base + (off))
+
+/* error code and state */
+enum {
+	ERR_NONE	= 0,
+	ERR_DMABUSERR	= -1,
+	ERR_SENDCMD	= -2,
+	ERR_DBERR	= -3,
+	ERR_BBERR	= -4,
+};
+
+enum {
+	STATE_READY	= 0,
+	STATE_CMD_HANDLE,
+	STATE_DMA_READING,
+	STATE_DMA_WRITING,
+	STATE_DMA_DONE,
+	STATE_PIO_READING,
+	STATE_PIO_WRITING,
+};
+
+struct pxa3xx_nand_timing {
+	unsigned int	tCH;  /* Enable signal hold time */
+	unsigned int	tCS;  /* Enable signal setup time */
+	unsigned int	tWH;  /* ND_nWE high duration */
+	unsigned int	tWP;  /* ND_nWE pulse time */
+	unsigned int	tRH;  /* ND_nRE high duration */
+	unsigned int	tRP;  /* ND_nRE pulse width */
+	unsigned int	tR;   /* ND_nWE high to ND_nRE low for read */
+	unsigned int	tWHR; /* ND_nWE high to ND_nRE low for status read */
+	unsigned int	tAR;  /* ND_ALE low to ND_nRE low delay */
+};
+
+struct pxa3xx_nand_cmdset {
+	uint16_t	read1;
+	uint16_t	read2;
+	uint16_t	program;
+	uint16_t	read_status;
+	uint16_t	read_id;
+	uint16_t	erase;
+	uint16_t	reset;
+	uint16_t	lock;
+	uint16_t	unlock;
+	uint16_t	lock_status;
+};
+
+struct pxa3xx_nand_flash {
+	struct pxa3xx_nand_timing *timing; /* NAND Flash timing */
+	struct pxa3xx_nand_cmdset *cmdset;
+
+	uint32_t page_per_block;/* Pages per block (PG_PER_BLK) */
+	uint32_t page_size;	/* Page size in bytes (PAGE_SZ) */
+	uint32_t flash_width;	/* Width of Flash memory (DWIDTH_M) */
+	uint32_t dfc_width;	/* Width of flash controller(DWIDTH_C) */
+	uint32_t num_blocks;	/* Number of physical blocks in Flash */
+	uint32_t chip_id;
+
+	/* NOTE: these are automatically calculated, do not define */
+	size_t		oob_size;
+	size_t		read_id_bytes;
+
+	unsigned int	col_addr_cycles;
+	unsigned int	row_addr_cycles;
+};
+
+struct pxa3xx_nand_info {
+	struct nand_chip	nand_chip;
+
+	struct platform_device	 *pdev;
+	struct pxa3xx_nand_flash *flash_info;
+
+	struct clk		*clk;
+	void __iomem		*mmio_base;
+
+	unsigned int 		buf_start;
+	unsigned int		buf_count;
+
+	/* DMA information */
+	int			drcmr_dat;
+	int			drcmr_cmd;
+
+	unsigned char		*data_buff;
+	dma_addr_t 		data_buff_phys;
+	size_t			data_buff_size;
+	int 			data_dma_ch;
+	struct pxa_dma_desc	*data_desc;
+	dma_addr_t 		data_desc_addr;
+
+	uint32_t		reg_ndcr;
+
+	/* saved column/page_addr during CMD_SEQIN */
+	int			seqin_column;
+	int			seqin_page_addr;
+
+	/* relate to the command */
+	unsigned int		state;
+
+	int			use_ecc;	/* use HW ECC ? */
+	int			use_dma;	/* use DMA ? */
+
+	size_t			data_size;	/* data size in FIFO */
+	int 			retcode;
+	struct completion 	cmd_complete;
+
+	/* generated NDCBx register values */
+	uint32_t		ndcb0;
+	uint32_t		ndcb1;
+	uint32_t		ndcb2;
+};
+
+static int use_dma = 1;
+module_param(use_dma, bool, 0444);
+MODULE_PARM_DESC(use_dma, "enable DMA for data transfering to/from NAND HW");
+
+static struct pxa3xx_nand_cmdset smallpage_cmdset = {
+	.read1		= 0x0000,
+	.read2		= 0x0050,
+	.program	= 0x1080,
+	.read_status	= 0x0070,
+	.read_id	= 0x0090,
+	.erase		= 0xD060,
+	.reset		= 0x00FF,
+	.lock		= 0x002A,
+	.unlock		= 0x2423,
+	.lock_status	= 0x007A,
+};
+
+static struct pxa3xx_nand_cmdset largepage_cmdset = {
+	.read1		= 0x3000,
+	.read2		= 0x0050,
+	.program	= 0x1080,
+	.read_status	= 0x0070,
+	.read_id	= 0x0090,
+	.erase		= 0xD060,
+	.reset		= 0x00FF,
+	.lock		= 0x002A,
+	.unlock		= 0x2423,
+	.lock_status	= 0x007A,
+};
+
+static struct pxa3xx_nand_timing samsung512MbX16_timing = {
+	.tCH	= 10,
+	.tCS	= 0,
+	.tWH	= 20,
+	.tWP	= 40,
+	.tRH	= 30,
+	.tRP	= 40,
+	.tR	= 11123,
+	.tWHR	= 110,
+	.tAR	= 10,
+};
+
+static struct pxa3xx_nand_flash samsung512MbX16 = {
+	.timing		= &samsung512MbX16_timing,
+	.cmdset		= &smallpage_cmdset,
+	.page_per_block	= 32,
+	.page_size	= 512,
+	.flash_width	= 16,
+	.dfc_width	= 16,
+	.num_blocks	= 4096,
+	.chip_id	= 0x46ec,
+};
+
+static struct pxa3xx_nand_timing micron_timing = {
+	.tCH	= 10,
+	.tCS	= 25,
+	.tWH	= 15,
+	.tWP	= 25,
+	.tRH	= 15,
+	.tRP	= 25,
+	.tR	= 25000,
+	.tWHR	= 60,
+	.tAR	= 10,
+};
+
+static struct pxa3xx_nand_flash micron1GbX8 = {
+	.timing		= &micron_timing,
+	.cmdset		= &largepage_cmdset,
+	.page_per_block	= 64,
+	.page_size	= 2048,
+	.flash_width	= 8,
+	.dfc_width	= 8,
+	.num_blocks	= 1024,
+	.chip_id	= 0xa12c,
+};
+
+static struct pxa3xx_nand_flash micron1GbX16 = {
+	.timing		= &micron_timing,
+	.cmdset		= &largepage_cmdset,
+	.page_per_block	= 64,
+	.page_size	= 2048,
+	.flash_width	= 16,
+	.dfc_width	= 16,
+	.num_blocks	= 1024,
+	.chip_id	= 0xb12c,
+};
+
+static struct pxa3xx_nand_flash *builtin_flash_types[] = {
+	&samsung512MbX16,
+	&micron1GbX8,
+	&micron1GbX16,
+};
+
+#define NDTR0_tCH(c)	(min((c), 7) << 19)
+#define NDTR0_tCS(c)	(min((c), 7) << 16)
+#define NDTR0_tWH(c)	(min((c), 7) << 11)
+#define NDTR0_tWP(c)	(min((c), 7) << 8)
+#define NDTR0_tRH(c)	(min((c), 7) << 3)
+#define NDTR0_tRP(c)	(min((c), 7) << 0)
+
+#define NDTR1_tR(c)	(min((c), 65535) << 16)
+#define NDTR1_tWHR(c)	(min((c), 15) << 4)
+#define NDTR1_tAR(c)	(min((c), 15) << 0)
+
+/* convert nano-seconds to nand flash controller clock cycles */
+#define ns2cycle(ns, clk)	(int)(((ns) * (clk / 1000000) / 1000) + 1)
+
+static void pxa3xx_nand_set_timing(struct pxa3xx_nand_info *info,
+				   struct pxa3xx_nand_timing *t)
+{
+	unsigned long nand_clk = clk_get_rate(info->clk);
+	uint32_t ndtr0, ndtr1;
+
+	ndtr0 = NDTR0_tCH(ns2cycle(t->tCH, nand_clk)) |
+		NDTR0_tCS(ns2cycle(t->tCS, nand_clk)) |
+		NDTR0_tWH(ns2cycle(t->tWH, nand_clk)) |
+		NDTR0_tWP(ns2cycle(t->tWP, nand_clk)) |
+		NDTR0_tRH(ns2cycle(t->tRH, nand_clk)) |
+		NDTR0_tRP(ns2cycle(t->tRP, nand_clk));
+
+	ndtr1 = NDTR1_tR(ns2cycle(t->tR, nand_clk)) |
+		NDTR1_tWHR(ns2cycle(t->tWHR, nand_clk)) |
+		NDTR1_tAR(ns2cycle(t->tAR, nand_clk));
+
+	nand_writel(info, NDTR0CS0, ndtr0);
+	nand_writel(info, NDTR1CS0, ndtr1);
+}
+
+#define WAIT_EVENT_TIMEOUT	10
+
+static int wait_for_event(struct pxa3xx_nand_info *info, uint32_t event)
+{
+	int timeout = WAIT_EVENT_TIMEOUT;
+	uint32_t ndsr;
+
+	while (timeout--) {
+		ndsr = nand_readl(info, NDSR) & NDSR_MASK;
+		if (ndsr & event) {
+			nand_writel(info, NDSR, ndsr);
+			return 0;
+		}
+		udelay(10);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int prepare_read_prog_cmd(struct pxa3xx_nand_info *info,
+			uint16_t cmd, int column, int page_addr)
+{
+	struct pxa3xx_nand_flash *f = info->flash_info;
+	struct pxa3xx_nand_cmdset *cmdset = f->cmdset;
+
+	/* calculate data size */
+	switch (f->page_size) {
+	case 2048:
+		info->data_size = (info->use_ecc) ? 2088 : 2112;
+		break;
+	case 512:
+		info->data_size = (info->use_ecc) ? 520 : 528;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* generate values for NDCBx registers */
+	info->ndcb0 = cmd | ((cmd & 0xff00) ? NDCB0_DBC : 0);
+	info->ndcb1 = 0;
+	info->ndcb2 = 0;
+	info->ndcb0 |= NDCB0_ADDR_CYC(f->row_addr_cycles + f->col_addr_cycles);
+
+	if (f->col_addr_cycles == 2) {
+		/* large block, 2 cycles for column address
+		 * row address starts from 3rd cycle
+		 */
+		info->ndcb1 |= (page_addr << 16) | (column & 0xffff);
+		if (f->row_addr_cycles == 3)
+			info->ndcb2 = (page_addr >> 16) & 0xff;
+	} else
+		/* small block, 1 cycles for column address
+		 * row address starts from 2nd cycle
+		 */
+		info->ndcb1 = (page_addr << 8) | (column & 0xff);
+
+	if (cmd == cmdset->program)
+		info->ndcb0 |= NDCB0_CMD_TYPE(1) | NDCB0_AUTO_RS;
+
+	return 0;
+}
+
+static int prepare_erase_cmd(struct pxa3xx_nand_info *info,
+			uint16_t cmd, int page_addr)
+{
+	info->ndcb0 = cmd | ((cmd & 0xff00) ? NDCB0_DBC : 0);
+	info->ndcb0 |= NDCB0_CMD_TYPE(2) | NDCB0_AUTO_RS | NDCB0_ADDR_CYC(3);
+	info->ndcb1 = page_addr;
+	info->ndcb2 = 0;
+	return 0;
+}
+
+static int prepare_other_cmd(struct pxa3xx_nand_info *info, uint16_t cmd)
+{
+	struct pxa3xx_nand_cmdset *cmdset = info->flash_info->cmdset;
+
+	info->ndcb0 = cmd | ((cmd & 0xff00) ? NDCB0_DBC : 0);
+	info->ndcb1 = 0;
+	info->ndcb2 = 0;
+
+	if (cmd == cmdset->read_id) {
+		info->ndcb0 |= NDCB0_CMD_TYPE(3);
+		info->data_size = 8;
+	} else if (cmd == cmdset->read_status) {
+		info->ndcb0 |= NDCB0_CMD_TYPE(4);
+		info->data_size = 8;
+	} else if (cmd == cmdset->reset || cmd == cmdset->lock ||
+		   cmd == cmdset->unlock) {
+		info->ndcb0 |= NDCB0_CMD_TYPE(5);
+	} else
+		return -EINVAL;
+
+	return 0;
+}
+
+static void enable_int(struct pxa3xx_nand_info *info, uint32_t int_mask)
+{
+	uint32_t ndcr;
+
+	ndcr = nand_readl(info, NDCR);
+	nand_writel(info, NDCR, ndcr & ~int_mask);
+}
+
+static void disable_int(struct pxa3xx_nand_info *info, uint32_t int_mask)
+{
+	uint32_t ndcr;
+
+	ndcr = nand_readl(info, NDCR);
+	nand_writel(info, NDCR, ndcr | int_mask);
+}
+
+/* NOTE: it is a must to set ND_RUN firstly, then write command buffer
+ * otherwise, it does not work
+ */
+static int write_cmd(struct pxa3xx_nand_info *info)
+{
+	uint32_t ndcr;
+
+	/* clear status bits and run */
+	nand_writel(info, NDSR, NDSR_MASK);
+
+	ndcr = info->reg_ndcr;
+
+	ndcr |= info->use_ecc ? NDCR_ECC_EN : 0;
+	ndcr |= info->use_dma ? NDCR_DMA_EN : 0;
+	ndcr |= NDCR_ND_RUN;
+
+	nand_writel(info, NDCR, ndcr);
+
+	if (wait_for_event(info, NDSR_WRCMDREQ)) {
+		printk(KERN_ERR "timed out writing command\n");
+		return -ETIMEDOUT;
+	}
+
+	nand_writel(info, NDCB0, info->ndcb0);
+	nand_writel(info, NDCB0, info->ndcb1);
+	nand_writel(info, NDCB0, info->ndcb2);
+	return 0;
+}
+
+static int handle_data_pio(struct pxa3xx_nand_info *info)
+{
+	int ret, timeout = CHIP_DELAY_TIMEOUT;
+
+	switch (info->state) {
+	case STATE_PIO_WRITING:
+		__raw_writesl(info->mmio_base + NDDB, info->data_buff,
+				info->data_size << 2);
+
+		enable_int(info, NDSR_CS0_BBD | NDSR_CS0_CMDD);
+
+		ret = wait_for_completion_timeout(&info->cmd_complete, timeout);
+		if (!ret) {
+			printk(KERN_ERR "program command time out\n");
+			return -1;
+		}
+		break;
+	case STATE_PIO_READING:
+		__raw_readsl(info->mmio_base + NDDB, info->data_buff,
+				info->data_size << 2);
+		break;
+	default:
+		printk(KERN_ERR "%s: invalid state %d\n", __FUNCTION__,
+				info->state);
+		return -EINVAL;
+	}
+
+	info->state = STATE_READY;
+	return 0;
+}
+
+static void start_data_dma(struct pxa3xx_nand_info *info, int dir_out)
+{
+	struct pxa_dma_desc *desc = info->data_desc;
+	int dma_len = ALIGN(info->data_size, 32);
+
+	desc->ddadr = DDADR_STOP;
+	desc->dcmd = DCMD_ENDIRQEN | DCMD_WIDTH4 | DCMD_BURST32 | dma_len;
+
+	if (dir_out) {
+		desc->dsadr = info->data_buff_phys;
+		desc->dtadr = NDDB_DMA_ADDR;
+		desc->dcmd |= DCMD_INCSRCADDR | DCMD_FLOWTRG;
+	} else {
+		desc->dtadr = info->data_buff_phys;
+		desc->dsadr = NDDB_DMA_ADDR;
+		desc->dcmd |= DCMD_INCTRGADDR | DCMD_FLOWSRC;
+	}
+
+	DRCMR(info->drcmr_dat) = DRCMR_MAPVLD | info->data_dma_ch;
+	DDADR(info->data_dma_ch) = info->data_desc_addr;
+	DCSR(info->data_dma_ch) |= DCSR_RUN;
+}
+
+static void pxa3xx_nand_data_dma_irq(int channel, void *data)
+{
+	struct pxa3xx_nand_info *info = data;
+	uint32_t dcsr;
+
+	dcsr = DCSR(channel);
+	DCSR(channel) = dcsr;
+
+	if (dcsr & DCSR_BUSERR) {
+		info->retcode = ERR_DMABUSERR;
+		complete(&info->cmd_complete);
+	}
+
+	if (info->state == STATE_DMA_WRITING) {
+		info->state = STATE_DMA_DONE;
+		enable_int(info, NDSR_CS0_BBD | NDSR_CS0_CMDD);
+	} else {
+		info->state = STATE_READY;
+		complete(&info->cmd_complete);
+	}
+}
+
+static irqreturn_t pxa3xx_nand_irq(int irq, void *devid)
+{
+	struct pxa3xx_nand_info *info = devid;
+	unsigned int status;
+
+	status = nand_readl(info, NDSR);
+
+	if (status & (NDSR_RDDREQ | NDSR_DBERR)) {
+		if (status & NDSR_DBERR)
+			info->retcode = ERR_DBERR;
+
+		disable_int(info, NDSR_RDDREQ | NDSR_DBERR);
+
+		if (info->use_dma) {
+			info->state = STATE_DMA_READING;
+			start_data_dma(info, 0);
+		} else {
+			info->state = STATE_PIO_READING;
+			complete(&info->cmd_complete);
+		}
+	} else if (status & NDSR_WRDREQ) {
+		disable_int(info, NDSR_WRDREQ);
+		if (info->use_dma) {
+			info->state = STATE_DMA_WRITING;
+			start_data_dma(info, 1);
+		} else {
+			info->state = STATE_PIO_WRITING;
+			complete(&info->cmd_complete);
+		}
+	} else if (status & (NDSR_CS0_BBD | NDSR_CS0_CMDD)) {
+		if (status & NDSR_CS0_BBD)
+			info->retcode = ERR_BBERR;
+
+		disable_int(info, NDSR_CS0_BBD | NDSR_CS0_CMDD);
+		info->state = STATE_READY;
+		complete(&info->cmd_complete);
+	}
+	nand_writel(info, NDSR, status);
+	return IRQ_HANDLED;
+}
+
+static int pxa3xx_nand_do_cmd(struct pxa3xx_nand_info *info, uint32_t event)
+{
+	uint32_t ndcr;
+	int ret, timeout = CHIP_DELAY_TIMEOUT;
+
+	if (write_cmd(info)) {
+		info->retcode = ERR_SENDCMD;
+		goto fail_stop;
+	}
+
+	info->state = STATE_CMD_HANDLE;
+
+	enable_int(info, event);
+
+	ret = wait_for_completion_timeout(&info->cmd_complete, timeout);
+	if (!ret) {
+		printk(KERN_ERR "command execution timed out\n");
+		info->retcode = ERR_SENDCMD;
+		goto fail_stop;
+	}
+
+	if (info->use_dma == 0 && info->data_size > 0)
+		if (handle_data_pio(info))
+			goto fail_stop;
+
+	return 0;
+
+fail_stop:
+	ndcr = nand_readl(info, NDCR);
+	nand_writel(info, NDCR, ndcr & ~NDCR_ND_RUN);
+	udelay(10);
+	return -ETIMEDOUT;
+}
+
+static int pxa3xx_nand_dev_ready(struct mtd_info *mtd)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	return (nand_readl(info, NDSR) & NDSR_RDY) ? 1 : 0;
+}
+
+static inline int is_buf_blank(uint8_t *buf, size_t len)
+{
+	for (; len > 0; len--)
+		if (*buf++ != 0xff)
+			return 0;
+	return 1;
+}
+
+static void pxa3xx_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
+		int column, int page_addr )
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	struct pxa3xx_nand_flash * flash_info = info->flash_info;
+	struct pxa3xx_nand_cmdset *cmdset = flash_info->cmdset;
+	int ret;
+
+	info->use_dma = (use_dma) ? 1 : 0;
+	info->use_ecc = 0;
+	info->data_size = 0;
+	info->state = STATE_READY;
+
+	init_completion(&info->cmd_complete);
+
+	switch (command) {
+	case NAND_CMD_READOOB:
+		/* disable HW ECC to get all the OOB data */
+		info->buf_count = mtd->writesize + mtd->oobsize;
+		info->buf_start = mtd->writesize + column;
+
+		if (prepare_read_prog_cmd(info, cmdset->read1, column, page_addr))
+			break;
+
+		pxa3xx_nand_do_cmd(info, NDSR_RDDREQ | NDSR_DBERR);
+
+		/* We only are OOB, so if the data has error, does not matter */
+		if (info->retcode == ERR_DBERR)
+			info->retcode = ERR_NONE;
+		break;
+
+	case NAND_CMD_READ0:
+		info->use_ecc = 1;
+		info->retcode = ERR_NONE;
+		info->buf_start = column;
+		info->buf_count = mtd->writesize + mtd->oobsize;
+		memset(info->data_buff, 0xFF, info->buf_count);
+
+		if (prepare_read_prog_cmd(info, cmdset->read1, column, page_addr))
+			break;
+
+		pxa3xx_nand_do_cmd(info, NDSR_RDDREQ | NDSR_DBERR);
+
+		if (info->retcode == ERR_DBERR) {
+			/* for blank page (all 0xff), HW will calculate its ECC as
+			 * 0, which is different from the ECC information within
+			 * OOB, ignore such double bit errors
+			 */
+			if (is_buf_blank(info->data_buff, mtd->writesize))
+				info->retcode = ERR_NONE;
+		}
+		break;
+	case NAND_CMD_SEQIN:
+		info->buf_start = column;
+		info->buf_count = mtd->writesize + mtd->oobsize;
+		memset(info->data_buff, 0xff, info->buf_count);
+
+		/* save column/page_addr for next CMD_PAGEPROG */
+		info->seqin_column = column;
+		info->seqin_page_addr = page_addr;
+		break;
+	case NAND_CMD_PAGEPROG:
+		info->use_ecc = (info->seqin_column >= mtd->writesize) ? 0 : 1;
+
+		if (prepare_read_prog_cmd(info, cmdset->program,
+				info->seqin_column, info->seqin_page_addr))
+			break;
+
+		pxa3xx_nand_do_cmd(info, NDSR_WRDREQ);
+		break;
+	case NAND_CMD_ERASE1:
+		if (prepare_erase_cmd(info, cmdset->erase, page_addr))
+			break;
+
+		pxa3xx_nand_do_cmd(info, NDSR_CS0_BBD | NDSR_CS0_CMDD);
+		break;
+	case NAND_CMD_ERASE2:
+		break;
+	case NAND_CMD_READID:
+	case NAND_CMD_STATUS:
+		info->use_dma = 0;	/* force PIO read */
+		info->buf_start = 0;
+		info->buf_count = (command == NAND_CMD_READID) ?
+				flash_info->read_id_bytes : 1;
+
+		if (prepare_other_cmd(info, (command == NAND_CMD_READID) ?
+				cmdset->read_id : cmdset->read_status))
+			break;
+
+		pxa3xx_nand_do_cmd(info, NDSR_RDDREQ);
+		break;
+	case NAND_CMD_RESET:
+		if (prepare_other_cmd(info, cmdset->reset))
+			break;
+
+		ret = pxa3xx_nand_do_cmd(info, NDSR_CS0_CMDD);
+		if (ret == 0) {
+			int timeout = 2;
+			uint32_t ndcr;
+
+			while (timeout--) {
+				if (nand_readl(info, NDSR) & NDSR_RDY)
+					break;
+				msleep(10);
+			}
+
+			ndcr = nand_readl(info, NDCR);
+			nand_writel(info, NDCR, ndcr & ~NDCR_ND_RUN);
+		}
+		break;
+	default:
+		printk(KERN_ERR "non-supported command.\n");
+		break;
+	}
+
+	if (info->retcode == ERR_DBERR) {
+		printk(KERN_ERR "double bit error @ page %08x\n", page_addr);
+		info->retcode = ERR_NONE;
+	}
+}
+
+static uint8_t pxa3xx_nand_read_byte(struct mtd_info *mtd)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	char retval = 0xFF;
+
+	if (info->buf_start < info->buf_count)
+		/* Has just send a new command? */
+		retval = info->data_buff[info->buf_start++];
+
+	return retval;
+}
+
+static u16 pxa3xx_nand_read_word(struct mtd_info *mtd)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	u16 retval = 0xFFFF;
+
+	if (!(info->buf_start & 0x01) && info->buf_start < info->buf_count) {
+		retval = *((u16 *)(info->data_buff+info->buf_start));
+		info->buf_start += 2;
+	}
+	return retval;
+}
+
+static void pxa3xx_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	int real_len = min_t(size_t, len, info->buf_count - info->buf_start);
+
+	memcpy(buf, info->data_buff + info->buf_start, real_len);
+	info->buf_start += real_len;
+}
+
+static void pxa3xx_nand_write_buf(struct mtd_info *mtd,
+		const uint8_t *buf, int len)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	int real_len = min_t(size_t, len, info->buf_count - info->buf_start);
+
+	memcpy(info->data_buff + info->buf_start, buf, real_len);
+	info->buf_start += real_len;
+}
+
+static int pxa3xx_nand_verify_buf(struct mtd_info *mtd,
+		const uint8_t *buf, int len)
+{
+	return 0;
+}
+
+static void pxa3xx_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+	return;
+}
+
+static int pxa3xx_nand_waitfunc(struct mtd_info *mtd, struct nand_chip *this)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+
+	/* pxa3xx_nand_send_command has waited for command complete */
+	if (this->state == FL_WRITING || this->state == FL_ERASING) {
+		if (info->retcode == ERR_NONE)
+			return 0;
+		else {
+			/*
+			 * any error make it return 0x01 which will tell
+			 * the caller the erase and write fail
+			 */
+			return 0x01;
+		}
+	}
+
+	return 0;
+}
+
+static void pxa3xx_nand_ecc_hwctl(struct mtd_info *mtd, int mode)
+{
+	return;
+}
+
+static int pxa3xx_nand_ecc_calculate(struct mtd_info *mtd,
+		const uint8_t *dat, uint8_t *ecc_code)
+{
+	return 0;
+}
+
+static int pxa3xx_nand_ecc_correct(struct mtd_info *mtd,
+		uint8_t *dat, uint8_t *read_ecc, uint8_t *calc_ecc)
+{
+	struct pxa3xx_nand_info *info = mtd->priv;
+	/*
+	 * Any error include ERR_SEND_CMD, ERR_DBERR, ERR_BUSERR, we
+	 * consider it as a ecc error which will tell the caller the
+	 * read fail We have distinguish all the errors, but the
+	 * nand_read_ecc only check this function return value
+	 */
+	if (info->retcode != ERR_NONE)
+		return -1;
+
+	return 0;
+}
+
+static int __readid(struct pxa3xx_nand_info *info, uint32_t *id)
+{
+	struct pxa3xx_nand_flash *f = info->flash_info;
+	struct pxa3xx_nand_cmdset *cmdset = f->cmdset;
+	uint32_t ndcr;
+	uint8_t  id_buff[8];
+
+	if (prepare_other_cmd(info, cmdset->read_id)) {
+		printk(KERN_ERR "failed to prepare command\n");
+		return -EINVAL;
+	}
+
+	/* Send command */
+	if (write_cmd(info))
+		goto fail_timeout;
+
+	/* Wait for CMDDM(command done successfully) */
+	if (wait_for_event(info, NDSR_RDDREQ))
+		goto fail_timeout;
+
+	__raw_readsl(info->mmio_base + NDDB, id_buff, 2);
+	*id = id_buff[0] | (id_buff[1] << 8);
+	return 0;
+
+fail_timeout:
+	ndcr = nand_readl(info, NDCR);
+	nand_writel(info, NDCR, ndcr & ~NDCR_ND_RUN);
+	udelay(10);
+	return -ETIMEDOUT;
+}
+
+static int pxa3xx_nand_config_flash(struct pxa3xx_nand_info *info,
+				    struct pxa3xx_nand_flash *f)
+{
+	struct platform_device *pdev = info->pdev;
+	struct pxa3xx_nand_platform_data *pdata = pdev->dev.platform_data;
+	uint32_t ndcr = 0x00000FFF; /* disable all interrupts */
+
+	if (f->page_size != 2048 && f->page_size != 512)
+		return -EINVAL;
+
+	if (f->flash_width != 16 && f->flash_width != 8)
+		return -EINVAL;
+
+	/* calculate flash information */
+	f->oob_size = (f->page_size == 2048) ? 64 : 16;
+	f->read_id_bytes = (f->page_size == 2048) ? 4 : 2;
+
+	/* calculate addressing information */
+	f->col_addr_cycles = (f->page_size == 2048) ? 2 : 1;
+
+	if (f->num_blocks * f->page_per_block > 65536)
+		f->row_addr_cycles = 3;
+	else
+		f->row_addr_cycles = 2;
+
+	ndcr |= (pdata->enable_arbiter) ? NDCR_ND_ARB_EN : 0;
+	ndcr |= (f->col_addr_cycles == 2) ? NDCR_RA_START : 0;
+	ndcr |= (f->page_per_block == 64) ? NDCR_PG_PER_BLK : 0;
+	ndcr |= (f->page_size == 2048) ? NDCR_PAGE_SZ : 0;
+	ndcr |= (f->flash_width == 16) ? NDCR_DWIDTH_M : 0;
+	ndcr |= (f->dfc_width == 16) ? NDCR_DWIDTH_C : 0;
+
+	ndcr |= NDCR_RD_ID_CNT(f->read_id_bytes);
+	ndcr |= NDCR_SPARE_EN; /* enable spare by default */
+
+	info->reg_ndcr = ndcr;
+
+	pxa3xx_nand_set_timing(info, f->timing);
+	info->flash_info = f;
+	return 0;
+}
+
+static int pxa3xx_nand_detect_flash(struct pxa3xx_nand_info *info)
+{
+	struct pxa3xx_nand_flash *f;
+	uint32_t id;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(builtin_flash_types); i++) {
+
+		f = builtin_flash_types[i];
+
+		if (pxa3xx_nand_config_flash(info, f))
+			continue;
+
+		if (__readid(info, &id))
+			continue;
+
+		if (id == f->chip_id)
+			return 0;
+	}
+
+	return -ENODEV;
+}
+
+/* the maximum possible buffer size for large page with OOB data
+ * is: 2048 + 64 = 2112 bytes, allocate a page here for both the
+ * data buffer and the DMA descriptor
+ */
+#define MAX_BUFF_SIZE	PAGE_SIZE
+
+static int pxa3xx_nand_init_buff(struct pxa3xx_nand_info *info)
+{
+	struct platform_device *pdev = info->pdev;
+	int data_desc_offset = MAX_BUFF_SIZE - sizeof(struct pxa_dma_desc);
+
+	if (use_dma == 0) {
+		info->data_buff = kmalloc(MAX_BUFF_SIZE, GFP_KERNEL);
+		if (info->data_buff == NULL)
+			return -ENOMEM;
+		return 0;
+	}
+
+	info->data_buff = dma_alloc_coherent(&pdev->dev, MAX_BUFF_SIZE,
+				&info->data_buff_phys, GFP_KERNEL);
+	if (info->data_buff == NULL) {
+		dev_err(&pdev->dev, "failed to allocate dma buffer\n");
+		return -ENOMEM;
+	}
+
+	info->data_buff_size = MAX_BUFF_SIZE;
+	info->data_desc = (void *)info->data_buff + data_desc_offset;
+	info->data_desc_addr = info->data_buff_phys + data_desc_offset;
+
+	info->data_dma_ch = pxa_request_dma("nand-data", DMA_PRIO_LOW,
+				pxa3xx_nand_data_dma_irq, info);
+	if (info->data_dma_ch < 0) {
+		dev_err(&pdev->dev, "failed to request data dma\n");
+		dma_free_coherent(&pdev->dev, info->data_buff_size,
+				info->data_buff, info->data_buff_phys);
+		return info->data_dma_ch;
+	}
+
+	return 0;
+}
+
+static struct nand_ecclayout hw_smallpage_ecclayout = {
+	.eccbytes = 6,
+	.eccpos = {8, 9, 10, 11, 12, 13 },
+	.oobfree = { {2, 6} }
+};
+
+static struct nand_ecclayout hw_largepage_ecclayout = {
+	.eccbytes = 24,
+	.eccpos = {
+		40, 41, 42, 43, 44, 45, 46, 47,
+		48, 49, 50, 51, 52, 53, 54, 55,
+		56, 57, 58, 59, 60, 61, 62, 63},
+	.oobfree = { {2, 38} }
+};
+
+static void pxa3xx_nand_init_mtd(struct mtd_info *mtd,
+				 struct pxa3xx_nand_info *info)
+{
+	struct pxa3xx_nand_flash *f = info->flash_info;
+	struct nand_chip *this = &info->nand_chip;
+
+	this->options = (f->flash_width == 16) ? NAND_BUSWIDTH_16: 0;
+
+	this->waitfunc		= pxa3xx_nand_waitfunc;
+	this->select_chip	= pxa3xx_nand_select_chip;
+	this->dev_ready		= pxa3xx_nand_dev_ready;
+	this->cmdfunc		= pxa3xx_nand_cmdfunc;
+	this->read_word		= pxa3xx_nand_read_word;
+	this->read_byte		= pxa3xx_nand_read_byte;
+	this->read_buf		= pxa3xx_nand_read_buf;
+	this->write_buf		= pxa3xx_nand_write_buf;
+	this->verify_buf	= pxa3xx_nand_verify_buf;
+
+	this->ecc.mode		= NAND_ECC_HW;
+	this->ecc.hwctl		= pxa3xx_nand_ecc_hwctl;
+	this->ecc.calculate	= pxa3xx_nand_ecc_calculate;
+	this->ecc.correct	= pxa3xx_nand_ecc_correct;
+	this->ecc.size		= f->page_size;
+
+	if (f->page_size == 2048)
+		this->ecc.layout = &hw_largepage_ecclayout;
+	else
+		this->ecc.layout = &hw_smallpage_ecclayout;
+
+	this->chip_delay= 25;
+}
+
+static int pxa3xx_nand_probe(struct platform_device *pdev)
+{
+	struct pxa3xx_nand_platform_data *pdata;
+	struct pxa3xx_nand_info *info;
+	struct nand_chip *this;
+	struct mtd_info *mtd;
+	struct resource *r;
+	int ret = 0, irq;
+
+	pdata = pdev->dev.platform_data;
+
+	if (pdata == NULL) {
+		dev_err(&pdev->dev, "no platform data defined\n");
+		return -ENODEV;
+	}
+
+	mtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct pxa3xx_nand_info),
+			GFP_KERNEL);
+	if (mtd == NULL) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+        }
+
+	info = (struct pxa3xx_nand_info *)(&mtd[1]);
+	info->pdev = pdev;
+
+	this = &info->nand_chip;
+	mtd->priv = info;
+
+	info->clk = clk_get(&pdev->dev, "NANDCLK");
+	if (IS_ERR(info->clk)) {
+		dev_err(&pdev->dev, "failed to get nand clock\n");
+		ret = PTR_ERR(info->clk);
+		goto fail_free_mtd;
+	}
+	clk_enable(info->clk);
+
+	r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (r == NULL) {
+		dev_err(&pdev->dev, "no resource defined for data DMA\n");
+		ret = -ENXIO;
+		goto fail_put_clk;
+	}
+	info->drcmr_dat = r->start;
+
+	r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
+	if (r == NULL) {
+		dev_err(&pdev->dev, "no resource defined for command DMA\n");
+		ret = -ENXIO;
+		goto fail_put_clk;
+	}
+	info->drcmr_cmd = r->start;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "no IRQ resource defined\n");
+		ret = -ENXIO;
+		goto fail_put_clk;
+	}
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (r == NULL) {
+		dev_err(&pdev->dev, "no IO memory resource defined\n");
+		ret = -ENODEV;
+		goto fail_put_clk;
+	}
+
+	r = request_mem_region(r->start, r->end - r->start + 1, pdev->name);
+	if (r == NULL) {
+		dev_err(&pdev->dev, "failed to request memory resource\n");
+		ret = -EBUSY;
+		goto fail_put_clk;
+	}
+
+	info->mmio_base = ioremap(r->start, r->end - r->start + 1);
+	if (info->mmio_base == NULL) {
+		dev_err(&pdev->dev, "ioremap() failed\n");
+		ret = -ENODEV;
+		goto fail_free_res;
+	}
+
+	ret = pxa3xx_nand_init_buff(info);
+	if (ret)
+		goto fail_free_io;
+
+	ret = request_irq(IRQ_NAND, pxa3xx_nand_irq, IRQF_DISABLED,
+				pdev->name, info);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to request IRQ\n");
+		goto fail_free_buf;
+	}
+
+	ret = pxa3xx_nand_detect_flash(info);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to detect flash\n");
+		ret = -ENODEV;
+		goto fail_free_irq;
+	}
+
+	pxa3xx_nand_init_mtd(mtd, info);
+
+	platform_set_drvdata(pdev, mtd);
+
+	if (nand_scan(mtd, 1)) {
+		dev_err(&pdev->dev, "failed to scan nand\n");
+		ret = -ENXIO;
+		goto fail_free_irq;
+	}
+
+	return add_mtd_partitions(mtd, pdata->parts, pdata->nr_parts);
+
+fail_free_irq:
+	free_irq(IRQ_NAND, info);
+fail_free_buf:
+	if (use_dma) {
+		pxa_free_dma(info->data_dma_ch);
+		dma_free_coherent(&pdev->dev, info->data_buff_size,
+			info->data_buff, info->data_buff_phys);
+	} else
+		kfree(info->data_buff);
+fail_free_io:
+	iounmap(info->mmio_base);
+fail_free_res:
+	release_mem_region(r->start, r->end - r->start + 1);
+fail_put_clk:
+	clk_disable(info->clk);
+	clk_put(info->clk);
+fail_free_mtd:
+	kfree(mtd);
+	return ret;
+}
+
+static int pxa3xx_nand_remove(struct platform_device *pdev)
+{
+	struct mtd_info *mtd = platform_get_drvdata(pdev);
+	struct pxa3xx_nand_info *info = mtd->priv;
+
+	platform_set_drvdata(pdev, NULL);
+
+	del_mtd_device(mtd);
+	del_mtd_partitions(mtd);
+	free_irq(IRQ_NAND, info);
+	if (use_dma) {
+		pxa_free_dma(info->data_dma_ch);
+		dma_free_writecombine(&pdev->dev, info->data_buff_size,
+				info->data_buff, info->data_buff_phys);
+	} else
+		kfree(info->data_buff);
+	kfree(mtd);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int pxa3xx_nand_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct mtd_info *mtd = (struct mtd_info *)platform_get_drvdata(pdev);
+	struct pxa3xx_nand_info *info = mtd->priv;
+
+	if (info->state != STATE_READY) {
+		dev_err(&pdev->dev, "driver busy, state = %d\n", info->state);
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static int pxa3xx_nand_resume(struct platform_device *pdev)
+{
+	struct mtd_info *mtd = (struct mtd_info *)platform_get_drvdata(pdev);
+	struct pxa3xx_nand_info *info = mtd->priv;
+
+	clk_enable(info->clk);
+
+	return pxa3xx_nand_config_flash(info);
+}
+#else
+#define pxa3xx_nand_suspend	NULL
+#define pxa3xx_nand_resume	NULL
+#endif
+
+static struct platform_driver pxa3xx_nand_driver = {
+	.driver = {
+		.name	= "pxa3xx-nand",
+	},
+	.probe		= pxa3xx_nand_probe,
+	.remove		= pxa3xx_nand_remove,
+	.suspend	= pxa3xx_nand_suspend,
+	.resume		= pxa3xx_nand_resume,
+};
+
+static int __init pxa3xx_nand_init(void)
+{
+	return platform_driver_register(&pxa3xx_nand_driver);
+}
+module_init(pxa3xx_nand_init);
+
+static void __exit pxa3xx_nand_exit(void)
+{
+	platform_driver_unregister(&pxa3xx_nand_driver);
+}
+module_exit(pxa3xx_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("PXA3xx NAND controller driver");