mtd: nand: add OMAP2/OMAP3 NAND driver

This driver is present in the OMAP tree, now pushing it to MTD.

Original author(s):
       Jian Zhang <jzhang@ti.com>

Signed-off-by: Vimal Singh <vimalsingh@ti.com>
Cc: Jian Zhang <jzhang@ti.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 776 insertions, 0 deletions

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
new file mode 100644
index 00000000000..0cd76f89f4b
--- /dev/null
+++ b/drivers/mtd/nand/omap2.c
@@ -0,0 +1,776 @@
+/*
+ * Copyright © 2004 Texas Instruments, Jian Zhang <jzhang@ti.com>
+ * Copyright © 2004 Micron Technology Inc.
+ * Copyright © 2004 David Brownell
+ *
+ * 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/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/io.h>
+
+#include <asm/dma.h>
+
+#include <mach/gpmc.h>
+#include <mach/nand.h>
+
+#define GPMC_IRQ_STATUS		0x18
+#define GPMC_ECC_CONFIG		0x1F4
+#define GPMC_ECC_CONTROL	0x1F8
+#define GPMC_ECC_SIZE_CONFIG	0x1FC
+#define GPMC_ECC1_RESULT	0x200
+
+#define	DRIVER_NAME	"omap2-nand"
+
+/* size (4 KiB) for IO mapping */
+#define	NAND_IO_SIZE	SZ_4K
+
+#define	NAND_WP_OFF	0
+#define NAND_WP_BIT	0x00000010
+#define WR_RD_PIN_MONITORING	0x00600000
+
+#define	GPMC_BUF_FULL	0x00000001
+#define	GPMC_BUF_EMPTY	0x00000000
+
+#define NAND_Ecc_P1e		(1 << 0)
+#define NAND_Ecc_P2e		(1 << 1)
+#define NAND_Ecc_P4e		(1 << 2)
+#define NAND_Ecc_P8e		(1 << 3)
+#define NAND_Ecc_P16e		(1 << 4)
+#define NAND_Ecc_P32e		(1 << 5)
+#define NAND_Ecc_P64e		(1 << 6)
+#define NAND_Ecc_P128e		(1 << 7)
+#define NAND_Ecc_P256e		(1 << 8)
+#define NAND_Ecc_P512e		(1 << 9)
+#define NAND_Ecc_P1024e		(1 << 10)
+#define NAND_Ecc_P2048e		(1 << 11)
+
+#define NAND_Ecc_P1o		(1 << 16)
+#define NAND_Ecc_P2o		(1 << 17)
+#define NAND_Ecc_P4o		(1 << 18)
+#define NAND_Ecc_P8o		(1 << 19)
+#define NAND_Ecc_P16o		(1 << 20)
+#define NAND_Ecc_P32o		(1 << 21)
+#define NAND_Ecc_P64o		(1 << 22)
+#define NAND_Ecc_P128o		(1 << 23)
+#define NAND_Ecc_P256o		(1 << 24)
+#define NAND_Ecc_P512o		(1 << 25)
+#define NAND_Ecc_P1024o		(1 << 26)
+#define NAND_Ecc_P2048o		(1 << 27)
+
+#define TF(value)	(value ? 1 : 0)
+
+#define P2048e(a)	(TF(a & NAND_Ecc_P2048e)	<< 0)
+#define P2048o(a)	(TF(a & NAND_Ecc_P2048o)	<< 1)
+#define P1e(a)		(TF(a & NAND_Ecc_P1e)		<< 2)
+#define P1o(a)		(TF(a & NAND_Ecc_P1o)		<< 3)
+#define P2e(a)		(TF(a & NAND_Ecc_P2e)		<< 4)
+#define P2o(a)		(TF(a & NAND_Ecc_P2o)		<< 5)
+#define P4e(a)		(TF(a & NAND_Ecc_P4e)		<< 6)
+#define P4o(a)		(TF(a & NAND_Ecc_P4o)		<< 7)
+
+#define P8e(a)		(TF(a & NAND_Ecc_P8e)		<< 0)
+#define P8o(a)		(TF(a & NAND_Ecc_P8o)		<< 1)
+#define P16e(a)		(TF(a & NAND_Ecc_P16e)		<< 2)
+#define P16o(a)		(TF(a & NAND_Ecc_P16o)		<< 3)
+#define P32e(a)		(TF(a & NAND_Ecc_P32e)		<< 4)
+#define P32o(a)		(TF(a & NAND_Ecc_P32o)		<< 5)
+#define P64e(a)		(TF(a & NAND_Ecc_P64e)		<< 6)
+#define P64o(a)		(TF(a & NAND_Ecc_P64o)		<< 7)
+
+#define P128e(a)	(TF(a & NAND_Ecc_P128e)		<< 0)
+#define P128o(a)	(TF(a & NAND_Ecc_P128o)		<< 1)
+#define P256e(a)	(TF(a & NAND_Ecc_P256e)		<< 2)
+#define P256o(a)	(TF(a & NAND_Ecc_P256o)		<< 3)
+#define P512e(a)	(TF(a & NAND_Ecc_P512e)		<< 4)
+#define P512o(a)	(TF(a & NAND_Ecc_P512o)		<< 5)
+#define P1024e(a)	(TF(a & NAND_Ecc_P1024e)	<< 6)
+#define P1024o(a)	(TF(a & NAND_Ecc_P1024o)	<< 7)
+
+#define P8e_s(a)	(TF(a & NAND_Ecc_P8e)		<< 0)
+#define P8o_s(a)	(TF(a & NAND_Ecc_P8o)		<< 1)
+#define P16e_s(a)	(TF(a & NAND_Ecc_P16e)		<< 2)
+#define P16o_s(a)	(TF(a & NAND_Ecc_P16o)		<< 3)
+#define P1e_s(a)	(TF(a & NAND_Ecc_P1e)		<< 4)
+#define P1o_s(a)	(TF(a & NAND_Ecc_P1o)		<< 5)
+#define P2e_s(a)	(TF(a & NAND_Ecc_P2e)		<< 6)
+#define P2o_s(a)	(TF(a & NAND_Ecc_P2o)		<< 7)
+
+#define P4e_s(a)	(TF(a & NAND_Ecc_P4e)		<< 0)
+#define P4o_s(a)	(TF(a & NAND_Ecc_P4o)		<< 1)
+
+#ifdef CONFIG_MTD_PARTITIONS
+static const char *part_probes[] = { "cmdlinepart", NULL };
+#endif
+
+struct omap_nand_info {
+	struct nand_hw_control		controller;
+	struct omap_nand_platform_data	*pdata;
+	struct mtd_info			mtd;
+	struct mtd_partition		*parts;
+	struct nand_chip		nand;
+	struct platform_device		*pdev;
+
+	int				gpmc_cs;
+	unsigned long			phys_base;
+	void __iomem			*gpmc_cs_baseaddr;
+	void __iomem			*gpmc_baseaddr;
+};
+
+/**
+ * omap_nand_wp - This function enable or disable the Write Protect feature
+ * @mtd: MTD device structure
+ * @mode: WP ON/OFF
+ */
+static void omap_nand_wp(struct mtd_info *mtd, int mode)
+{
+	struct omap_nand_info *info = container_of(mtd,
+						struct omap_nand_info, mtd);
+
+	unsigned long config = __raw_readl(info->gpmc_baseaddr + GPMC_CONFIG);
+
+	if (mode)
+		config &= ~(NAND_WP_BIT);	/* WP is ON */
+	else
+		config |= (NAND_WP_BIT);	/* WP is OFF */
+
+	__raw_writel(config, (info->gpmc_baseaddr + GPMC_CONFIG));
+}
+
+/**
+ * omap_hwcontrol - hardware specific access to control-lines
+ * @mtd: MTD device structure
+ * @cmd: command to device
+ * @ctrl:
+ * NAND_NCE: bit 0 -> don't care
+ * NAND_CLE: bit 1 -> Command Latch
+ * NAND_ALE: bit 2 -> Address Latch
+ *
+ * NOTE: boards may use different bits for these!!
+ */
+static void omap_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+	struct omap_nand_info *info = container_of(mtd,
+					struct omap_nand_info, mtd);
+	switch (ctrl) {
+	case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
+		info->nand.IO_ADDR_W = info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_COMMAND;
+		info->nand.IO_ADDR_R = info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_DATA;
+		break;
+
+	case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
+		info->nand.IO_ADDR_W = info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_ADDRESS;
+		info->nand.IO_ADDR_R = info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_DATA;
+		break;
+
+	case NAND_CTRL_CHANGE | NAND_NCE:
+		info->nand.IO_ADDR_W = info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_DATA;
+		info->nand.IO_ADDR_R = info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_DATA;
+		break;
+	}
+
+	if (cmd != NAND_CMD_NONE)
+		__raw_writeb(cmd, info->nand.IO_ADDR_W);
+}
+
+/**
+ * omap_read_buf16 - read data from NAND controller into buffer
+ * @mtd: MTD device structure
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ */
+static void omap_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
+{
+	struct nand_chip *nand = mtd->priv;
+
+	__raw_readsw(nand->IO_ADDR_R, buf, len / 2);
+}
+
+/**
+ * omap_write_buf16 - write buffer to NAND controller
+ * @mtd: MTD device structure
+ * @buf: data buffer
+ * @len: number of bytes to write
+ */
+static void omap_write_buf16(struct mtd_info *mtd, const u_char * buf, int len)
+{
+	struct omap_nand_info *info = container_of(mtd,
+						struct omap_nand_info, mtd);
+	u16 *p = (u16 *) buf;
+
+	/* FIXME try bursts of writesw() or DMA ... */
+	len >>= 1;
+
+	while (len--) {
+		writew(*p++, info->nand.IO_ADDR_W);
+
+		while (GPMC_BUF_EMPTY == (readl(info->gpmc_baseaddr +
+						GPMC_STATUS) & GPMC_BUF_FULL))
+			;
+	}
+}
+/**
+ * omap_verify_buf - Verify chip data against buffer
+ * @mtd: MTD device structure
+ * @buf: buffer containing the data to compare
+ * @len: number of bytes to compare
+ */
+static int omap_verify_buf(struct mtd_info *mtd, const u_char * buf, int len)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	u16 *p = (u16 *) buf;
+
+	len >>= 1;
+	while (len--) {
+		if (*p++ != cpu_to_le16(readw(info->nand.IO_ADDR_R)))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_MTD_NAND_OMAP_HWECC
+/**
+ * omap_hwecc_init - Initialize the HW ECC for NAND flash in GPMC controller
+ * @mtd: MTD device structure
+ */
+static void omap_hwecc_init(struct mtd_info *mtd)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	struct nand_chip *chip = mtd->priv;
+	unsigned long val = 0x0;
+
+	/* Read from ECC Control Register */
+	val = __raw_readl(info->gpmc_baseaddr + GPMC_ECC_CONTROL);
+	/* Clear all ECC | Enable Reg1 */
+	val = ((0x00000001<<8) | 0x00000001);
+	__raw_writel(val, info->gpmc_baseaddr + GPMC_ECC_CONTROL);
+
+	/* Read from ECC Size Config Register */
+	val = __raw_readl(info->gpmc_baseaddr + GPMC_ECC_SIZE_CONFIG);
+	/* ECCSIZE1=512 | Select eccResultsize[0-3] */
+	val = ((((chip->ecc.size >> 1) - 1) << 22) | (0x0000000F));
+	__raw_writel(val, info->gpmc_baseaddr + GPMC_ECC_SIZE_CONFIG);
+}
+
+/**
+ * gen_true_ecc - This function will generate true ECC value
+ * @ecc_buf: buffer to store ecc code
+ *
+ * This generated true ECC value can be used when correcting
+ * data read from NAND flash memory core
+ */
+static void gen_true_ecc(u8 *ecc_buf)
+{
+	u32 tmp = ecc_buf[0] | (ecc_buf[1] << 16) |
+		((ecc_buf[2] & 0xF0) << 20) | ((ecc_buf[2] & 0x0F) << 8);
+
+	ecc_buf[0] = ~(P64o(tmp) | P64e(tmp) | P32o(tmp) | P32e(tmp) |
+			P16o(tmp) | P16e(tmp) | P8o(tmp) | P8e(tmp));
+	ecc_buf[1] = ~(P1024o(tmp) | P1024e(tmp) | P512o(tmp) | P512e(tmp) |
+			P256o(tmp) | P256e(tmp) | P128o(tmp) | P128e(tmp));
+	ecc_buf[2] = ~(P4o(tmp) | P4e(tmp) | P2o(tmp) | P2e(tmp) | P1o(tmp) |
+			P1e(tmp) | P2048o(tmp) | P2048e(tmp));
+}
+
+/**
+ * omap_compare_ecc - Detect (2 bits) and correct (1 bit) error in data
+ * @ecc_data1:  ecc code from nand spare area
+ * @ecc_data2:  ecc code from hardware register obtained from hardware ecc
+ * @page_data:  page data
+ *
+ * This function compares two ECC's and indicates if there is an error.
+ * If the error can be corrected it will be corrected to the buffer.
+ */
+static int omap_compare_ecc(u8 *ecc_data1,	/* read from NAND memory */
+			    u8 *ecc_data2,	/* read from register */
+			    u8 *page_data)
+{
+	uint	i;
+	u8	tmp0_bit[8], tmp1_bit[8], tmp2_bit[8];
+	u8	comp0_bit[8], comp1_bit[8], comp2_bit[8];
+	u8	ecc_bit[24];
+	u8	ecc_sum = 0;
+	u8	find_bit = 0;
+	uint	find_byte = 0;
+	int	isEccFF;
+
+	isEccFF = ((*(u32 *)ecc_data1 & 0xFFFFFF) == 0xFFFFFF);
+
+	gen_true_ecc(ecc_data1);
+	gen_true_ecc(ecc_data2);
+
+	for (i = 0; i <= 2; i++) {
+		*(ecc_data1 + i) = ~(*(ecc_data1 + i));
+		*(ecc_data2 + i) = ~(*(ecc_data2 + i));
+	}
+
+	for (i = 0; i < 8; i++) {
+		tmp0_bit[i]     = *ecc_data1 % 2;
+		*ecc_data1	= *ecc_data1 / 2;
+	}
+
+	for (i = 0; i < 8; i++) {
+		tmp1_bit[i]	 = *(ecc_data1 + 1) % 2;
+		*(ecc_data1 + 1) = *(ecc_data1 + 1) / 2;
+	}
+
+	for (i = 0; i < 8; i++) {
+		tmp2_bit[i]	 = *(ecc_data1 + 2) % 2;
+		*(ecc_data1 + 2) = *(ecc_data1 + 2) / 2;
+	}
+
+	for (i = 0; i < 8; i++) {
+		comp0_bit[i]     = *ecc_data2 % 2;
+		*ecc_data2       = *ecc_data2 / 2;
+	}
+
+	for (i = 0; i < 8; i++) {
+		comp1_bit[i]     = *(ecc_data2 + 1) % 2;
+		*(ecc_data2 + 1) = *(ecc_data2 + 1) / 2;
+	}
+
+	for (i = 0; i < 8; i++) {
+		comp2_bit[i]     = *(ecc_data2 + 2) % 2;
+		*(ecc_data2 + 2) = *(ecc_data2 + 2) / 2;
+	}
+
+	for (i = 0; i < 6; i++)
+		ecc_bit[i] = tmp2_bit[i + 2] ^ comp2_bit[i + 2];
+
+	for (i = 0; i < 8; i++)
+		ecc_bit[i + 6] = tmp0_bit[i] ^ comp0_bit[i];
+
+	for (i = 0; i < 8; i++)
+		ecc_bit[i + 14] = tmp1_bit[i] ^ comp1_bit[i];
+
+	ecc_bit[22] = tmp2_bit[0] ^ comp2_bit[0];
+	ecc_bit[23] = tmp2_bit[1] ^ comp2_bit[1];
+
+	for (i = 0; i < 24; i++)
+		ecc_sum += ecc_bit[i];
+
+	switch (ecc_sum) {
+	case 0:
+		/* Not reached because this function is not called if
+		 *  ECC values are equal
+		 */
+		return 0;
+
+	case 1:
+		/* Uncorrectable error */
+		DEBUG(MTD_DEBUG_LEVEL0, "ECC UNCORRECTED_ERROR 1\n");
+		return -1;
+
+	case 11:
+		/* UN-Correctable error */
+		DEBUG(MTD_DEBUG_LEVEL0, "ECC UNCORRECTED_ERROR B\n");
+		return -1;
+
+	case 12:
+		/* Correctable error */
+		find_byte = (ecc_bit[23] << 8) +
+			    (ecc_bit[21] << 7) +
+			    (ecc_bit[19] << 6) +
+			    (ecc_bit[17] << 5) +
+			    (ecc_bit[15] << 4) +
+			    (ecc_bit[13] << 3) +
+			    (ecc_bit[11] << 2) +
+			    (ecc_bit[9]  << 1) +
+			    ecc_bit[7];
+
+		find_bit = (ecc_bit[5] << 2) + (ecc_bit[3] << 1) + ecc_bit[1];
+
+		DEBUG(MTD_DEBUG_LEVEL0, "Correcting single bit ECC error at "
+				"offset: %d, bit: %d\n", find_byte, find_bit);
+
+		page_data[find_byte] ^= (1 << find_bit);
+
+		return 0;
+	default:
+		if (isEccFF) {
+			if (ecc_data2[0] == 0 &&
+			    ecc_data2[1] == 0 &&
+			    ecc_data2[2] == 0)
+				return 0;
+		}
+		DEBUG(MTD_DEBUG_LEVEL0, "UNCORRECTED_ERROR default\n");
+		return -1;
+	}
+}
+
+/**
+ * omap_correct_data - Compares the ECC read with HW generated ECC
+ * @mtd: MTD device structure
+ * @dat: page data
+ * @read_ecc: ecc read from nand flash
+ * @calc_ecc: ecc read from HW ECC registers
+ *
+ * Compares the ecc read from nand spare area with ECC registers values
+ * and if ECC's mismached, it will call 'omap_compare_ecc' for error detection
+ * and correction.
+ */
+static int omap_correct_data(struct mtd_info *mtd, u_char *dat,
+				u_char *read_ecc, u_char *calc_ecc)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	int blockCnt = 0, i = 0, ret = 0;
+
+	/* Ex NAND_ECC_HW12_2048 */
+	if ((info->nand.ecc.mode == NAND_ECC_HW) &&
+			(info->nand.ecc.size  == 2048))
+		blockCnt = 4;
+	else
+		blockCnt = 1;
+
+	for (i = 0; i < blockCnt; i++) {
+		if (memcmp(read_ecc, calc_ecc, 3) != 0) {
+			ret = omap_compare_ecc(read_ecc, calc_ecc, dat);
+			if (ret < 0)
+				return ret;
+		}
+		read_ecc += 3;
+		calc_ecc += 3;
+		dat      += 512;
+	}
+	return 0;
+}
+
+/**
+ * omap_calcuate_ecc - Generate non-inverted ECC bytes.
+ * @mtd: MTD device structure
+ * @dat: The pointer to data on which ecc is computed
+ * @ecc_code: The ecc_code buffer
+ *
+ * Using noninverted ECC can be considered ugly since writing a blank
+ * page ie. padding will clear the ECC bytes. This is no problem as long
+ * nobody is trying to write data on the seemingly unused page. Reading
+ * an erased page will produce an ECC mismatch between generated and read
+ * ECC bytes that has to be dealt with separately.
+ */
+static int omap_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
+				u_char *ecc_code)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	unsigned long val = 0x0;
+	unsigned long reg;
+
+	/* Start Reading from HW ECC1_Result = 0x200 */
+	reg = (unsigned long)(info->gpmc_baseaddr + GPMC_ECC1_RESULT);
+	val = __raw_readl(reg);
+	*ecc_code++ = val;          /* P128e, ..., P1e */
+	*ecc_code++ = val >> 16;    /* P128o, ..., P1o */
+	/* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
+	*ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);
+	reg += 4;
+
+	return 0;
+}
+
+/**
+ * omap_enable_hwecc - This function enables the hardware ecc functionality
+ * @mtd: MTD device structure
+ * @mode: Read/Write mode
+ */
+static void omap_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	struct nand_chip *chip = mtd->priv;
+	unsigned int dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
+	unsigned long val = __raw_readl(info->gpmc_baseaddr + GPMC_ECC_CONFIG);
+
+	switch (mode) {
+	case NAND_ECC_READ:
+		__raw_writel(0x101, info->gpmc_baseaddr + GPMC_ECC_CONTROL);
+		/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
+		val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
+		break;
+	case NAND_ECC_READSYN:
+		 __raw_writel(0x100, info->gpmc_baseaddr + GPMC_ECC_CONTROL);
+		/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
+		val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
+		break;
+	case NAND_ECC_WRITE:
+		__raw_writel(0x101, info->gpmc_baseaddr + GPMC_ECC_CONTROL);
+		/* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
+		val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
+		break;
+	default:
+		DEBUG(MTD_DEBUG_LEVEL0, "Error: Unrecognized Mode[%d]!\n",
+					mode);
+		break;
+	}
+
+	__raw_writel(val, info->gpmc_baseaddr + GPMC_ECC_CONFIG);
+}
+#endif
+
+/**
+ * omap_wait - wait until the command is done
+ * @mtd: MTD device structure
+ * @chip: NAND Chip structure
+ *
+ * Wait function is called during Program and erase operations and
+ * the way it is called from MTD layer, we should wait till the NAND
+ * chip is ready after the programming/erase operation has completed.
+ *
+ * Erase can take up to 400ms and program up to 20ms according to
+ * general NAND and SmartMedia specs
+ */
+static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
+{
+	struct nand_chip *this = mtd->priv;
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	unsigned long timeo = jiffies;
+	int status, state = this->state;
+
+	if (state == FL_ERASING)
+		timeo += (HZ * 400) / 1000;
+	else
+		timeo += (HZ * 20) / 1000;
+
+	this->IO_ADDR_W = (void *) info->gpmc_cs_baseaddr +
+						GPMC_CS_NAND_COMMAND;
+	this->IO_ADDR_R = (void *) info->gpmc_cs_baseaddr + GPMC_CS_NAND_DATA;
+
+	__raw_writeb(NAND_CMD_STATUS & 0xFF, this->IO_ADDR_W);
+
+	while (time_before(jiffies, timeo)) {
+		status = __raw_readb(this->IO_ADDR_R);
+		if (!(status & 0x40))
+			break;
+	}
+	return status;
+}
+
+/**
+ * omap_dev_ready - calls the platform specific dev_ready function
+ * @mtd: MTD device structure
+ */
+static int omap_dev_ready(struct mtd_info *mtd)
+{
+	struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+							mtd);
+	unsigned int val = __raw_readl(info->gpmc_baseaddr + GPMC_IRQ_STATUS);
+
+	if ((val & 0x100) == 0x100) {
+		/* Clear IRQ Interrupt */
+		val |= 0x100;
+		val &= ~(0x0);
+		__raw_writel(val, info->gpmc_baseaddr + GPMC_IRQ_STATUS);
+	} else {
+		unsigned int cnt = 0;
+		while (cnt++ < 0x1FF) {
+			if  ((val & 0x100) == 0x100)
+				return 0;
+			val = __raw_readl(info->gpmc_baseaddr +
+							GPMC_IRQ_STATUS);
+		}
+	}
+
+	return 1;
+}
+
+static int __devinit omap_nand_probe(struct platform_device *pdev)
+{
+	struct omap_nand_info		*info;
+	struct omap_nand_platform_data	*pdata;
+	int				err;
+	unsigned long 			val;
+
+
+	pdata = pdev->dev.platform_data;
+	if (pdata == NULL) {
+		dev_err(&pdev->dev, "platform data missing\n");
+		return -ENODEV;
+	}
+
+	info = kzalloc(sizeof(struct omap_nand_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, info);
+
+	spin_lock_init(&info->controller.lock);
+	init_waitqueue_head(&info->controller.wq);
+
+	info->pdev = pdev;
+
+	info->gpmc_cs		= pdata->cs;
+	info->gpmc_baseaddr	= pdata->gpmc_baseaddr;
+	info->gpmc_cs_baseaddr	= pdata->gpmc_cs_baseaddr;
+
+	info->mtd.priv		= &info->nand;
+	info->mtd.name		= dev_name(&pdev->dev);
+	info->mtd.owner		= THIS_MODULE;
+
+	err = gpmc_cs_request(info->gpmc_cs, NAND_IO_SIZE, &info->phys_base);
+	if (err < 0) {
+		dev_err(&pdev->dev, "Cannot request GPMC CS\n");
+		goto out_free_info;
+	}
+
+	/* Enable RD PIN Monitoring Reg */
+	if (pdata->dev_ready) {
+		val  = gpmc_cs_read_reg(info->gpmc_cs, GPMC_CS_CONFIG1);
+		val |= WR_RD_PIN_MONITORING;
+		gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG1, val);
+	}
+
+	val  = gpmc_cs_read_reg(info->gpmc_cs, GPMC_CS_CONFIG7);
+	val &= ~(0xf << 8);
+	val |=  (0xc & 0xf) << 8;
+	gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG7, val);
+
+	/* NAND write protect off */
+	omap_nand_wp(&info->mtd, NAND_WP_OFF);
+
+	if (!request_mem_region(info->phys_base, NAND_IO_SIZE,
+				pdev->dev.driver->name)) {
+		err = -EBUSY;
+		goto out_free_cs;
+	}
+
+	info->nand.IO_ADDR_R = ioremap(info->phys_base, NAND_IO_SIZE);
+	if (!info->nand.IO_ADDR_R) {
+		err = -ENOMEM;
+		goto out_release_mem_region;
+	}
+	info->nand.controller = &info->controller;
+
+	info->nand.IO_ADDR_W = info->nand.IO_ADDR_R;
+	info->nand.cmd_ctrl  = omap_hwcontrol;
+
+	/* REVISIT:  only supports 16-bit NAND flash */
+
+	info->nand.read_buf   = omap_read_buf16;
+	info->nand.write_buf  = omap_write_buf16;
+	info->nand.verify_buf = omap_verify_buf;
+
+	/*
+	 * If RDY/BSY line is connected to OMAP then use the omap ready
+	 * funcrtion and the generic nand_wait function which reads the status
+	 * register after monitoring the RDY/BSY line.Otherwise use a standard
+	 * chip delay which is slightly more than tR (AC Timing) of the NAND
+	 * device and read status register until you get a failure or success
+	 */
+	if (pdata->dev_ready) {
+		info->nand.dev_ready = omap_dev_ready;
+		info->nand.chip_delay = 0;
+	} else {
+		info->nand.waitfunc = omap_wait;
+		info->nand.chip_delay = 50;
+	}
+
+	info->nand.options  |= NAND_SKIP_BBTSCAN;
+	if ((gpmc_cs_read_reg(info->gpmc_cs, GPMC_CS_CONFIG1) & 0x3000)
+								== 0x1000)
+		info->nand.options  |= NAND_BUSWIDTH_16;
+
+#ifdef CONFIG_MTD_NAND_OMAP_HWECC
+	info->nand.ecc.bytes		= 3;
+	info->nand.ecc.size		= 512;
+	info->nand.ecc.calculate	= omap_calculate_ecc;
+	info->nand.ecc.hwctl		= omap_enable_hwecc;
+	info->nand.ecc.correct		= omap_correct_data;
+	info->nand.ecc.mode		= NAND_ECC_HW;
+
+	/* init HW ECC */
+	omap_hwecc_init(&info->mtd);
+#else
+	info->nand.ecc.mode = NAND_ECC_SOFT;
+#endif
+
+	/* DIP switches on some boards change between 8 and 16 bit
+	 * bus widths for flash.  Try the other width if the first try fails.
+	 */
+	if (nand_scan(&info->mtd, 1)) {
+		info->nand.options ^= NAND_BUSWIDTH_16;
+		if (nand_scan(&info->mtd, 1)) {
+			err = -ENXIO;
+			goto out_release_mem_region;
+		}
+	}
+
+#ifdef CONFIG_MTD_PARTITIONS
+	err = parse_mtd_partitions(&info->mtd, part_probes, &info->parts, 0);
+	if (err > 0)
+		add_mtd_partitions(&info->mtd, info->parts, err);
+	else if (pdata->parts)
+		add_mtd_partitions(&info->mtd, pdata->parts, pdata->nr_parts);
+	else
+#endif
+		add_mtd_device(&info->mtd);
+
+	platform_set_drvdata(pdev, &info->mtd);
+
+	return 0;
+
+out_release_mem_region:
+	release_mem_region(info->phys_base, NAND_IO_SIZE);
+out_free_cs:
+	gpmc_cs_free(info->gpmc_cs);
+out_free_info:
+	kfree(info);
+
+	return err;
+}
+
+static int omap_nand_remove(struct platform_device *pdev)
+{
+	struct mtd_info *mtd = platform_get_drvdata(pdev);
+	struct omap_nand_info *info = mtd->priv;
+
+	platform_set_drvdata(pdev, NULL);
+	/* Release NAND device, its internal structures and partitions */
+	nand_release(&info->mtd);
+	iounmap(info->nand.IO_ADDR_R);
+	kfree(&info->mtd);
+	return 0;
+}
+
+static struct platform_driver omap_nand_driver = {
+	.probe		= omap_nand_probe,
+	.remove		= omap_nand_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init omap_nand_init(void)
+{
+	printk(KERN_INFO "%s driver initializing\n", DRIVER_NAME);
+	return platform_driver_register(&omap_nand_driver);
+}
+
+static void __exit omap_nand_exit(void)
+{
+	platform_driver_unregister(&omap_nand_driver);
+}
+
+module_init(omap_nand_init);
+module_exit(omap_nand_exit);
+
+MODULE_ALIAS(DRIVER_NAME);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Glue layer for NAND flash on TI OMAP boards");