Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 864 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/davinci_nand.c b/drivers/mtd/nand/raw/davinci_nand.c
new file mode 100644
index 000000000..66d3d5966
--- /dev/null
+++ b/drivers/mtd/nand/raw/davinci_nand.c
@@ -0,0 +1,864 @@
+/*
+ * davinci_nand.c - NAND Flash Driver for DaVinci family chips
+ *
+ * Copyright © 2006 Texas Instruments.
+ *
+ * Port to 2.6.23 Copyright © 2008 by:
+ *   Sander Huijsen <Shuijsen@optelecom-nkf.com>
+ *   Troy Kisky <troy.kisky@boundarydevices.com>
+ *   Dirk Behme <Dirk.Behme@gmail.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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+
+#include <linux/platform_data/mtd-davinci.h>
+#include <linux/platform_data/mtd-davinci-aemif.h>
+
+/*
+ * This is a device driver for the NAND flash controller found on the
+ * various DaVinci family chips.  It handles up to four SoC chipselects,
+ * and some flavors of secondary chipselect (e.g. based on A12) as used
+ * with multichip packages.
+ *
+ * The 1-bit ECC hardware is supported, as well as the newer 4-bit ECC
+ * available on chips like the DM355 and OMAP-L137 and needed with the
+ * more error-prone MLC NAND chips.
+ *
+ * This driver assumes EM_WAIT connects all the NAND devices' RDY/nBUSY
+ * outputs in a "wire-AND" configuration, with no per-chip signals.
+ */
+struct davinci_nand_info {
+	struct nand_chip	chip;
+
+	struct platform_device	*pdev;
+
+	bool			is_readmode;
+
+	void __iomem		*base;
+	void __iomem		*vaddr;
+
+	void __iomem		*current_cs;
+
+	uint32_t		mask_chipsel;
+	uint32_t		mask_ale;
+	uint32_t		mask_cle;
+
+	uint32_t		core_chipsel;
+
+	struct davinci_aemif_timing	*timing;
+};
+
+static DEFINE_SPINLOCK(davinci_nand_lock);
+static bool ecc4_busy;
+
+static inline struct davinci_nand_info *to_davinci_nand(struct mtd_info *mtd)
+{
+	return container_of(mtd_to_nand(mtd), struct davinci_nand_info, chip);
+}
+
+static inline unsigned int davinci_nand_readl(struct davinci_nand_info *info,
+		int offset)
+{
+	return __raw_readl(info->base + offset);
+}
+
+static inline void davinci_nand_writel(struct davinci_nand_info *info,
+		int offset, unsigned long value)
+{
+	__raw_writel(value, info->base + offset);
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Access to hardware control lines:  ALE, CLE, secondary chipselect.
+ */
+
+static void nand_davinci_hwcontrol(struct mtd_info *mtd, int cmd,
+				   unsigned int ctrl)
+{
+	struct davinci_nand_info	*info = to_davinci_nand(mtd);
+	void __iomem			*addr = info->current_cs;
+	struct nand_chip		*nand = mtd_to_nand(mtd);
+
+	/* Did the control lines change? */
+	if (ctrl & NAND_CTRL_CHANGE) {
+		if ((ctrl & NAND_CTRL_CLE) == NAND_CTRL_CLE)
+			addr += info->mask_cle;
+		else if ((ctrl & NAND_CTRL_ALE) == NAND_CTRL_ALE)
+			addr += info->mask_ale;
+
+		nand->IO_ADDR_W = addr;
+	}
+
+	if (cmd != NAND_CMD_NONE)
+		iowrite8(cmd, nand->IO_ADDR_W);
+}
+
+static void nand_davinci_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct davinci_nand_info	*info = to_davinci_nand(mtd);
+
+	info->current_cs = info->vaddr;
+
+	/* maybe kick in a second chipselect */
+	if (chip > 0)
+		info->current_cs += info->mask_chipsel;
+
+	info->chip.IO_ADDR_W = info->current_cs;
+	info->chip.IO_ADDR_R = info->chip.IO_ADDR_W;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * 1-bit hardware ECC ... context maintained for each core chipselect
+ */
+
+static inline uint32_t nand_davinci_readecc_1bit(struct mtd_info *mtd)
+{
+	struct davinci_nand_info *info = to_davinci_nand(mtd);
+
+	return davinci_nand_readl(info, NANDF1ECC_OFFSET
+			+ 4 * info->core_chipsel);
+}
+
+static void nand_davinci_hwctl_1bit(struct mtd_info *mtd, int mode)
+{
+	struct davinci_nand_info *info;
+	uint32_t nandcfr;
+	unsigned long flags;
+
+	info = to_davinci_nand(mtd);
+
+	/* Reset ECC hardware */
+	nand_davinci_readecc_1bit(mtd);
+
+	spin_lock_irqsave(&davinci_nand_lock, flags);
+
+	/* Restart ECC hardware */
+	nandcfr = davinci_nand_readl(info, NANDFCR_OFFSET);
+	nandcfr |= BIT(8 + info->core_chipsel);
+	davinci_nand_writel(info, NANDFCR_OFFSET, nandcfr);
+
+	spin_unlock_irqrestore(&davinci_nand_lock, flags);
+}
+
+/*
+ * Read hardware ECC value and pack into three bytes
+ */
+static int nand_davinci_calculate_1bit(struct mtd_info *mtd,
+				      const u_char *dat, u_char *ecc_code)
+{
+	unsigned int ecc_val = nand_davinci_readecc_1bit(mtd);
+	unsigned int ecc24 = (ecc_val & 0x0fff) | ((ecc_val & 0x0fff0000) >> 4);
+
+	/* invert so that erased block ecc is correct */
+	ecc24 = ~ecc24;
+	ecc_code[0] = (u_char)(ecc24);
+	ecc_code[1] = (u_char)(ecc24 >> 8);
+	ecc_code[2] = (u_char)(ecc24 >> 16);
+
+	return 0;
+}
+
+static int nand_davinci_correct_1bit(struct mtd_info *mtd, u_char *dat,
+				     u_char *read_ecc, u_char *calc_ecc)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	uint32_t eccNand = read_ecc[0] | (read_ecc[1] << 8) |
+					  (read_ecc[2] << 16);
+	uint32_t eccCalc = calc_ecc[0] | (calc_ecc[1] << 8) |
+					  (calc_ecc[2] << 16);
+	uint32_t diff = eccCalc ^ eccNand;
+
+	if (diff) {
+		if ((((diff >> 12) ^ diff) & 0xfff) == 0xfff) {
+			/* Correctable error */
+			if ((diff >> (12 + 3)) < chip->ecc.size) {
+				dat[diff >> (12 + 3)] ^= BIT((diff >> 12) & 7);
+				return 1;
+			} else {
+				return -EBADMSG;
+			}
+		} else if (!(diff & (diff - 1))) {
+			/* Single bit ECC error in the ECC itself,
+			 * nothing to fix */
+			return 1;
+		} else {
+			/* Uncorrectable error */
+			return -EBADMSG;
+		}
+
+	}
+	return 0;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * 4-bit hardware ECC ... context maintained over entire AEMIF
+ *
+ * This is a syndrome engine, but we avoid NAND_ECC_HW_SYNDROME
+ * since that forces use of a problematic "infix OOB" layout.
+ * Among other things, it trashes manufacturer bad block markers.
+ * Also, and specific to this hardware, it ECC-protects the "prepad"
+ * in the OOB ... while having ECC protection for parts of OOB would
+ * seem useful, the current MTD stack sometimes wants to update the
+ * OOB without recomputing ECC.
+ */
+
+static void nand_davinci_hwctl_4bit(struct mtd_info *mtd, int mode)
+{
+	struct davinci_nand_info *info = to_davinci_nand(mtd);
+	unsigned long flags;
+	u32 val;
+
+	/* Reset ECC hardware */
+	davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET);
+
+	spin_lock_irqsave(&davinci_nand_lock, flags);
+
+	/* Start 4-bit ECC calculation for read/write */
+	val = davinci_nand_readl(info, NANDFCR_OFFSET);
+	val &= ~(0x03 << 4);
+	val |= (info->core_chipsel << 4) | BIT(12);
+	davinci_nand_writel(info, NANDFCR_OFFSET, val);
+
+	info->is_readmode = (mode == NAND_ECC_READ);
+
+	spin_unlock_irqrestore(&davinci_nand_lock, flags);
+}
+
+/* Read raw ECC code after writing to NAND. */
+static void
+nand_davinci_readecc_4bit(struct davinci_nand_info *info, u32 code[4])
+{
+	const u32 mask = 0x03ff03ff;
+
+	code[0] = davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET) & mask;
+	code[1] = davinci_nand_readl(info, NAND_4BIT_ECC2_OFFSET) & mask;
+	code[2] = davinci_nand_readl(info, NAND_4BIT_ECC3_OFFSET) & mask;
+	code[3] = davinci_nand_readl(info, NAND_4BIT_ECC4_OFFSET) & mask;
+}
+
+/* Terminate read ECC; or return ECC (as bytes) of data written to NAND. */
+static int nand_davinci_calculate_4bit(struct mtd_info *mtd,
+		const u_char *dat, u_char *ecc_code)
+{
+	struct davinci_nand_info *info = to_davinci_nand(mtd);
+	u32 raw_ecc[4], *p;
+	unsigned i;
+
+	/* After a read, terminate ECC calculation by a dummy read
+	 * of some 4-bit ECC register.  ECC covers everything that
+	 * was read; correct() just uses the hardware state, so
+	 * ecc_code is not needed.
+	 */
+	if (info->is_readmode) {
+		davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET);
+		return 0;
+	}
+
+	/* Pack eight raw 10-bit ecc values into ten bytes, making
+	 * two passes which each convert four values (in upper and
+	 * lower halves of two 32-bit words) into five bytes.  The
+	 * ROM boot loader uses this same packing scheme.
+	 */
+	nand_davinci_readecc_4bit(info, raw_ecc);
+	for (i = 0, p = raw_ecc; i < 2; i++, p += 2) {
+		*ecc_code++ =   p[0]        & 0xff;
+		*ecc_code++ = ((p[0] >>  8) & 0x03) | ((p[0] >> 14) & 0xfc);
+		*ecc_code++ = ((p[0] >> 22) & 0x0f) | ((p[1] <<  4) & 0xf0);
+		*ecc_code++ = ((p[1] >>  4) & 0x3f) | ((p[1] >> 10) & 0xc0);
+		*ecc_code++ =  (p[1] >> 18) & 0xff;
+	}
+
+	return 0;
+}
+
+/* Correct up to 4 bits in data we just read, using state left in the
+ * hardware plus the ecc_code computed when it was first written.
+ */
+static int nand_davinci_correct_4bit(struct mtd_info *mtd,
+		u_char *data, u_char *ecc_code, u_char *null)
+{
+	int i;
+	struct davinci_nand_info *info = to_davinci_nand(mtd);
+	unsigned short ecc10[8];
+	unsigned short *ecc16;
+	u32 syndrome[4];
+	u32 ecc_state;
+	unsigned num_errors, corrected;
+	unsigned long timeo;
+
+	/* Unpack ten bytes into eight 10 bit values.  We know we're
+	 * little-endian, and use type punning for less shifting/masking.
+	 */
+	if (WARN_ON(0x01 & (uintptr_t)ecc_code))
+		return -EINVAL;
+	ecc16 = (unsigned short *)ecc_code;
+
+	ecc10[0] =  (ecc16[0] >>  0) & 0x3ff;
+	ecc10[1] = ((ecc16[0] >> 10) & 0x3f) | ((ecc16[1] << 6) & 0x3c0);
+	ecc10[2] =  (ecc16[1] >>  4) & 0x3ff;
+	ecc10[3] = ((ecc16[1] >> 14) & 0x3)  | ((ecc16[2] << 2) & 0x3fc);
+	ecc10[4] =  (ecc16[2] >>  8)         | ((ecc16[3] << 8) & 0x300);
+	ecc10[5] =  (ecc16[3] >>  2) & 0x3ff;
+	ecc10[6] = ((ecc16[3] >> 12) & 0xf)  | ((ecc16[4] << 4) & 0x3f0);
+	ecc10[7] =  (ecc16[4] >>  6) & 0x3ff;
+
+	/* Tell ECC controller about the expected ECC codes. */
+	for (i = 7; i >= 0; i--)
+		davinci_nand_writel(info, NAND_4BIT_ECC_LOAD_OFFSET, ecc10[i]);
+
+	/* Allow time for syndrome calculation ... then read it.
+	 * A syndrome of all zeroes 0 means no detected errors.
+	 */
+	davinci_nand_readl(info, NANDFSR_OFFSET);
+	nand_davinci_readecc_4bit(info, syndrome);
+	if (!(syndrome[0] | syndrome[1] | syndrome[2] | syndrome[3]))
+		return 0;
+
+	/*
+	 * Clear any previous address calculation by doing a dummy read of an
+	 * error address register.
+	 */
+	davinci_nand_readl(info, NAND_ERR_ADD1_OFFSET);
+
+	/* Start address calculation, and wait for it to complete.
+	 * We _could_ start reading more data while this is working,
+	 * to speed up the overall page read.
+	 */
+	davinci_nand_writel(info, NANDFCR_OFFSET,
+			davinci_nand_readl(info, NANDFCR_OFFSET) | BIT(13));
+
+	/*
+	 * ECC_STATE field reads 0x3 (Error correction complete) immediately
+	 * after setting the 4BITECC_ADD_CALC_START bit. So if you immediately
+	 * begin trying to poll for the state, you may fall right out of your
+	 * loop without any of the correction calculations having taken place.
+	 * The recommendation from the hardware team is to initially delay as
+	 * long as ECC_STATE reads less than 4. After that, ECC HW has entered
+	 * correction state.
+	 */
+	timeo = jiffies + usecs_to_jiffies(100);
+	do {
+		ecc_state = (davinci_nand_readl(info,
+				NANDFSR_OFFSET) >> 8) & 0x0f;
+		cpu_relax();
+	} while ((ecc_state < 4) && time_before(jiffies, timeo));
+
+	for (;;) {
+		u32	fsr = davinci_nand_readl(info, NANDFSR_OFFSET);
+
+		switch ((fsr >> 8) & 0x0f) {
+		case 0:		/* no error, should not happen */
+			davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
+			return 0;
+		case 1:		/* five or more errors detected */
+			davinci_nand_readl(info, NAND_ERR_ERRVAL1_OFFSET);
+			return -EBADMSG;
+		case 2:		/* error addresses computed */
+		case 3:
+			num_errors = 1 + ((fsr >> 16) & 0x03);
+			goto correct;
+		default:	/* still working on it */
+			cpu_relax();
+			continue;
+		}
+	}
+
+correct:
+	/* correct each error */
+	for (i = 0, corrected = 0; i < num_errors; i++) {
+		int error_address, error_value;
+
+		if (i > 1) {
+			error_address = davinci_nand_readl(info,
+						NAND_ERR_ADD2_OFFSET);
+			error_value = davinci_nand_readl(info,
+						NAND_ERR_ERRVAL2_OFFSET);
+		} else {
+			error_address = davinci_nand_readl(info,
+						NAND_ERR_ADD1_OFFSET);
+			error_value = davinci_nand_readl(info,
+						NAND_ERR_ERRVAL1_OFFSET);
+		}
+
+		if (i & 1) {
+			error_address >>= 16;
+			error_value >>= 16;
+		}
+		error_address &= 0x3ff;
+		error_address = (512 + 7) - error_address;
+
+		if (error_address < 512) {
+			data[error_address] ^= error_value;
+			corrected++;
+		}
+	}
+
+	return corrected;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * NOTE:  NAND boot requires ALE == EM_A[1], CLE == EM_A[2], so that's
+ * how these chips are normally wired.  This translates to both 8 and 16
+ * bit busses using ALE == BIT(3) in byte addresses, and CLE == BIT(4).
+ *
+ * For now we assume that configuration, or any other one which ignores
+ * the two LSBs for NAND access ... so we can issue 32-bit reads/writes
+ * and have that transparently morphed into multiple NAND operations.
+ */
+static void nand_davinci_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if ((0x03 & ((uintptr_t)buf)) == 0 && (0x03 & len) == 0)
+		ioread32_rep(chip->IO_ADDR_R, buf, len >> 2);
+	else if ((0x01 & ((uintptr_t)buf)) == 0 && (0x01 & len) == 0)
+		ioread16_rep(chip->IO_ADDR_R, buf, len >> 1);
+	else
+		ioread8_rep(chip->IO_ADDR_R, buf, len);
+}
+
+static void nand_davinci_write_buf(struct mtd_info *mtd,
+		const uint8_t *buf, int len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if ((0x03 & ((uintptr_t)buf)) == 0 && (0x03 & len) == 0)
+		iowrite32_rep(chip->IO_ADDR_R, buf, len >> 2);
+	else if ((0x01 & ((uintptr_t)buf)) == 0 && (0x01 & len) == 0)
+		iowrite16_rep(chip->IO_ADDR_R, buf, len >> 1);
+	else
+		iowrite8_rep(chip->IO_ADDR_R, buf, len);
+}
+
+/*
+ * Check hardware register for wait status. Returns 1 if device is ready,
+ * 0 if it is still busy.
+ */
+static int nand_davinci_dev_ready(struct mtd_info *mtd)
+{
+	struct davinci_nand_info *info = to_davinci_nand(mtd);
+
+	return davinci_nand_readl(info, NANDFSR_OFFSET) & BIT(0);
+}
+
+/*----------------------------------------------------------------------*/
+
+/* An ECC layout for using 4-bit ECC with small-page flash, storing
+ * ten ECC bytes plus the manufacturer's bad block marker byte, and
+ * and not overlapping the default BBT markers.
+ */
+static int hwecc4_ooblayout_small_ecc(struct mtd_info *mtd, int section,
+				      struct mtd_oob_region *oobregion)
+{
+	if (section > 2)
+		return -ERANGE;
+
+	if (!section) {
+		oobregion->offset = 0;
+		oobregion->length = 5;
+	} else if (section == 1) {
+		oobregion->offset = 6;
+		oobregion->length = 2;
+	} else {
+		oobregion->offset = 13;
+		oobregion->length = 3;
+	}
+
+	return 0;
+}
+
+static int hwecc4_ooblayout_small_free(struct mtd_info *mtd, int section,
+				       struct mtd_oob_region *oobregion)
+{
+	if (section > 1)
+		return -ERANGE;
+
+	if (!section) {
+		oobregion->offset = 8;
+		oobregion->length = 5;
+	} else {
+		oobregion->offset = 16;
+		oobregion->length = mtd->oobsize - 16;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops hwecc4_small_ooblayout_ops = {
+	.ecc = hwecc4_ooblayout_small_ecc,
+	.free = hwecc4_ooblayout_small_free,
+};
+
+#if defined(CONFIG_OF)
+static const struct of_device_id davinci_nand_of_match[] = {
+	{.compatible = "ti,davinci-nand", },
+	{.compatible = "ti,keystone-nand", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, davinci_nand_of_match);
+
+static struct davinci_nand_pdata
+	*nand_davinci_get_pdata(struct platform_device *pdev)
+{
+	if (!dev_get_platdata(&pdev->dev) && pdev->dev.of_node) {
+		struct davinci_nand_pdata *pdata;
+		const char *mode;
+		u32 prop;
+
+		pdata =  devm_kzalloc(&pdev->dev,
+				sizeof(struct davinci_nand_pdata),
+				GFP_KERNEL);
+		pdev->dev.platform_data = pdata;
+		if (!pdata)
+			return ERR_PTR(-ENOMEM);
+		if (!of_property_read_u32(pdev->dev.of_node,
+			"ti,davinci-chipselect", &prop))
+			pdata->core_chipsel = prop;
+		else
+			return ERR_PTR(-EINVAL);
+
+		if (!of_property_read_u32(pdev->dev.of_node,
+			"ti,davinci-mask-ale", &prop))
+			pdata->mask_ale = prop;
+		if (!of_property_read_u32(pdev->dev.of_node,
+			"ti,davinci-mask-cle", &prop))
+			pdata->mask_cle = prop;
+		if (!of_property_read_u32(pdev->dev.of_node,
+			"ti,davinci-mask-chipsel", &prop))
+			pdata->mask_chipsel = prop;
+		if (!of_property_read_string(pdev->dev.of_node,
+			"ti,davinci-ecc-mode", &mode)) {
+			if (!strncmp("none", mode, 4))
+				pdata->ecc_mode = NAND_ECC_NONE;
+			if (!strncmp("soft", mode, 4))
+				pdata->ecc_mode = NAND_ECC_SOFT;
+			if (!strncmp("hw", mode, 2))
+				pdata->ecc_mode = NAND_ECC_HW;
+		}
+		if (!of_property_read_u32(pdev->dev.of_node,
+			"ti,davinci-ecc-bits", &prop))
+			pdata->ecc_bits = prop;
+
+		if (!of_property_read_u32(pdev->dev.of_node,
+			"ti,davinci-nand-buswidth", &prop) && prop == 16)
+			pdata->options |= NAND_BUSWIDTH_16;
+
+		if (of_property_read_bool(pdev->dev.of_node,
+			"ti,davinci-nand-use-bbt"))
+			pdata->bbt_options = NAND_BBT_USE_FLASH;
+
+		/*
+		 * Since kernel v4.8, this driver has been fixed to enable
+		 * use of 4-bit hardware ECC with subpages and verified on
+		 * TI's keystone EVMs (K2L, K2HK and K2E).
+		 * However, in the interest of not breaking systems using
+		 * existing UBI partitions, sub-page writes are not being
+		 * (re)enabled. If you want to use subpage writes on Keystone
+		 * platforms (i.e. do not have any existing UBI partitions),
+		 * then use "ti,davinci-nand" as the compatible in your
+		 * device-tree file.
+		 */
+		if (of_device_is_compatible(pdev->dev.of_node,
+					    "ti,keystone-nand")) {
+			pdata->options |= NAND_NO_SUBPAGE_WRITE;
+		}
+	}
+
+	return dev_get_platdata(&pdev->dev);
+}
+#else
+static struct davinci_nand_pdata
+	*nand_davinci_get_pdata(struct platform_device *pdev)
+{
+	return dev_get_platdata(&pdev->dev);
+}
+#endif
+
+static int davinci_nand_attach_chip(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct davinci_nand_info *info = to_davinci_nand(mtd);
+	struct davinci_nand_pdata *pdata = nand_davinci_get_pdata(info->pdev);
+	int ret = 0;
+
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+
+	switch (info->chip.ecc.mode) {
+	case NAND_ECC_NONE:
+		pdata->ecc_bits = 0;
+		break;
+	case NAND_ECC_SOFT:
+		pdata->ecc_bits = 0;
+		/*
+		 * This driver expects Hamming based ECC when ecc_mode is set
+		 * to NAND_ECC_SOFT. Force ecc.algo to NAND_ECC_HAMMING to
+		 * avoid adding an extra ->ecc_algo field to
+		 * davinci_nand_pdata.
+		 */
+		info->chip.ecc.algo = NAND_ECC_HAMMING;
+		break;
+	case NAND_ECC_HW:
+		if (pdata->ecc_bits == 4) {
+			/*
+			 * No sanity checks:  CPUs must support this,
+			 * and the chips may not use NAND_BUSWIDTH_16.
+			 */
+
+			/* No sharing 4-bit hardware between chipselects yet */
+			spin_lock_irq(&davinci_nand_lock);
+			if (ecc4_busy)
+				ret = -EBUSY;
+			else
+				ecc4_busy = true;
+			spin_unlock_irq(&davinci_nand_lock);
+
+			if (ret == -EBUSY)
+				return ret;
+
+			info->chip.ecc.calculate = nand_davinci_calculate_4bit;
+			info->chip.ecc.correct = nand_davinci_correct_4bit;
+			info->chip.ecc.hwctl = nand_davinci_hwctl_4bit;
+			info->chip.ecc.bytes = 10;
+			info->chip.ecc.options = NAND_ECC_GENERIC_ERASED_CHECK;
+			info->chip.ecc.algo = NAND_ECC_BCH;
+		} else {
+			/* 1bit ecc hamming */
+			info->chip.ecc.calculate = nand_davinci_calculate_1bit;
+			info->chip.ecc.correct = nand_davinci_correct_1bit;
+			info->chip.ecc.hwctl = nand_davinci_hwctl_1bit;
+			info->chip.ecc.bytes = 3;
+			info->chip.ecc.algo = NAND_ECC_HAMMING;
+		}
+		info->chip.ecc.size = 512;
+		info->chip.ecc.strength = pdata->ecc_bits;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/*
+	 * Update ECC layout if needed ... for 1-bit HW ECC, the default
+	 * is OK, but it allocates 6 bytes when only 3 are needed (for
+	 * each 512 bytes).  For the 4-bit HW ECC, that default is not
+	 * usable:  10 bytes are needed, not 6.
+	 */
+	if (pdata->ecc_bits == 4) {
+		int chunks = mtd->writesize / 512;
+
+		if (!chunks || mtd->oobsize < 16) {
+			dev_dbg(&info->pdev->dev, "too small\n");
+			return -EINVAL;
+		}
+
+		/* For small page chips, preserve the manufacturer's
+		 * badblock marking data ... and make sure a flash BBT
+		 * table marker fits in the free bytes.
+		 */
+		if (chunks == 1) {
+			mtd_set_ooblayout(mtd, &hwecc4_small_ooblayout_ops);
+		} else if (chunks == 4 || chunks == 8) {
+			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
+			info->chip.ecc.mode = NAND_ECC_HW_OOB_FIRST;
+		} else {
+			return -EIO;
+		}
+	}
+
+	return ret;
+}
+
+static const struct nand_controller_ops davinci_nand_controller_ops = {
+	.attach_chip = davinci_nand_attach_chip,
+};
+
+static int nand_davinci_probe(struct platform_device *pdev)
+{
+	struct davinci_nand_pdata	*pdata;
+	struct davinci_nand_info	*info;
+	struct resource			*res1;
+	struct resource			*res2;
+	void __iomem			*vaddr;
+	void __iomem			*base;
+	int				ret;
+	uint32_t			val;
+	struct mtd_info			*mtd;
+
+	pdata = nand_davinci_get_pdata(pdev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+
+	/* insist on board-specific configuration */
+	if (!pdata)
+		return -ENODEV;
+
+	/* which external chipselect will we be managing? */
+	if (pdata->core_chipsel < 0 || pdata->core_chipsel > 3)
+		return -ENODEV;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, info);
+
+	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	res2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res1 || !res2) {
+		dev_err(&pdev->dev, "resource missing\n");
+		return -EINVAL;
+	}
+
+	vaddr = devm_ioremap_resource(&pdev->dev, res1);
+	if (IS_ERR(vaddr))
+		return PTR_ERR(vaddr);
+
+	/*
+	 * This registers range is used to setup NAND settings. In case with
+	 * TI AEMIF driver, the same memory address range is requested already
+	 * by AEMIF, so we cannot request it twice, just ioremap.
+	 * The AEMIF and NAND drivers not use the same registers in this range.
+	 */
+	base = devm_ioremap(&pdev->dev, res2->start, resource_size(res2));
+	if (!base) {
+		dev_err(&pdev->dev, "ioremap failed for resource %pR\n", res2);
+		return -EADDRNOTAVAIL;
+	}
+
+	info->pdev		= pdev;
+	info->base		= base;
+	info->vaddr		= vaddr;
+
+	mtd			= nand_to_mtd(&info->chip);
+	mtd->dev.parent		= &pdev->dev;
+	nand_set_flash_node(&info->chip, pdev->dev.of_node);
+
+	info->chip.IO_ADDR_R	= vaddr;
+	info->chip.IO_ADDR_W	= vaddr;
+	info->chip.chip_delay	= 0;
+	info->chip.select_chip	= nand_davinci_select_chip;
+
+	/* options such as NAND_BBT_USE_FLASH */
+	info->chip.bbt_options	= pdata->bbt_options;
+	/* options such as 16-bit widths */
+	info->chip.options	= pdata->options;
+	info->chip.bbt_td	= pdata->bbt_td;
+	info->chip.bbt_md	= pdata->bbt_md;
+	info->timing		= pdata->timing;
+
+	info->current_cs	= info->vaddr;
+	info->core_chipsel	= pdata->core_chipsel;
+	info->mask_chipsel	= pdata->mask_chipsel;
+
+	/* use nandboot-capable ALE/CLE masks by default */
+	info->mask_ale		= pdata->mask_ale ? : MASK_ALE;
+	info->mask_cle		= pdata->mask_cle ? : MASK_CLE;
+
+	/* Set address of hardware control function */
+	info->chip.cmd_ctrl	= nand_davinci_hwcontrol;
+	info->chip.dev_ready	= nand_davinci_dev_ready;
+
+	/* Speed up buffer I/O */
+	info->chip.read_buf     = nand_davinci_read_buf;
+	info->chip.write_buf    = nand_davinci_write_buf;
+
+	/* Use board-specific ECC config */
+	info->chip.ecc.mode	= pdata->ecc_mode;
+
+	spin_lock_irq(&davinci_nand_lock);
+
+	/* put CSxNAND into NAND mode */
+	val = davinci_nand_readl(info, NANDFCR_OFFSET);
+	val |= BIT(info->core_chipsel);
+	davinci_nand_writel(info, NANDFCR_OFFSET, val);
+
+	spin_unlock_irq(&davinci_nand_lock);
+
+	/* Scan to find existence of the device(s) */
+	info->chip.dummy_controller.ops = &davinci_nand_controller_ops;
+	ret = nand_scan(&info->chip, pdata->mask_chipsel ? 2 : 1);
+	if (ret < 0) {
+		dev_dbg(&pdev->dev, "no NAND chip(s) found\n");
+		return ret;
+	}
+
+	if (pdata->parts)
+		ret = mtd_device_register(mtd, pdata->parts, pdata->nr_parts);
+	else
+		ret = mtd_device_register(mtd, NULL, 0);
+	if (ret < 0)
+		goto err_cleanup_nand;
+
+	val = davinci_nand_readl(info, NRCSR_OFFSET);
+	dev_info(&pdev->dev, "controller rev. %d.%d\n",
+	       (val >> 8) & 0xff, val & 0xff);
+
+	return 0;
+
+err_cleanup_nand:
+	nand_cleanup(&info->chip);
+
+	return ret;
+}
+
+static int nand_davinci_remove(struct platform_device *pdev)
+{
+	struct davinci_nand_info *info = platform_get_drvdata(pdev);
+
+	spin_lock_irq(&davinci_nand_lock);
+	if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME)
+		ecc4_busy = false;
+	spin_unlock_irq(&davinci_nand_lock);
+
+	nand_release(&info->chip);
+
+	return 0;
+}
+
+static struct platform_driver nand_davinci_driver = {
+	.probe		= nand_davinci_probe,
+	.remove		= nand_davinci_remove,
+	.driver		= {
+		.name	= "davinci_nand",
+		.of_match_table = of_match_ptr(davinci_nand_of_match),
+	},
+};
+MODULE_ALIAS("platform:davinci_nand");
+
+module_platform_driver(nand_davinci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("Davinci NAND flash driver");
+