Merge tag 'mtd/for-4.17' of git://git.infradead.org/linux-mtd

Pull MTD updates from Boris Brezillon:
 "MTD Core:
   - Remove support for asynchronous erase (not implemented by any of
     the existing drivers anyway)
   - Remove Cyrille from the list of SPI NOR and MTD maintainers
   - Fix kernel doc headers
   - Allow users to define the partitions parsers they want to test
     through a DT property (compatible of the partitions subnode)
   - Remove the bfin-async-flash driver (the only architecture using it
     has been removed)
   - Fix pagetest test
   - Add extra checks in mtd_erase()
   - Simplify the MTD partition creation logic and get rid of
     mtd_add_device_partitions()

  MTD Drivers:
   - Add endianness information to the physmap DT binding
   - Add Eon EN29LV400A IDs to JEDEC probe logic
   - Use %*ph where appropriate

  SPI NOR Drivers:
   - Make fsl-quaspi assign different names to MTD devices connected to
     the same QSPI controller
   - Remove an unneeded driver.bus assigned in the fsl-qspi driver

  NAND Core:
   - Prepare arrival of the SPI NAND subsystem by implementing a generic
     (interface-agnostic) layer to ease manipulation of NAND devices
   - Move onenand code base to the drivers/mtd/nand/ dir
   - Rework timing mode selection
   - Provide a generic way for NAND chip drivers to flag a specific
     GET/SET FEATURE operation as supported/unsupported
   - Stop embedding ONFI/JEDEC param page in nand_chip

  NAND Drivers:
   - Rework/cleanup of the mxc driver
   - Various cleanups in the vf610 driver
   - Migrate the fsmc and vf610 to ->exec_op()
   - Get rid of the pxa driver (replaced by marvell_nand)
   - Support ->setup_data_interface() in the GPMI driver
   - Fix probe error path in several drivers
   - Remove support for unused hw_syndrome mode in sunxi_nand
   - Various minor improvements"

* tag 'mtd/for-4.17' of git://git.infradead.org/linux-mtd: (89 commits)
  dt-bindings: fsl-quadspi: Add the example of two SPI NOR
  mtd: fsl-quadspi: Distinguish the mtd device names
  mtd: nand: Fix some function description mismatches in core.c
  mtd: fsl-quadspi: Remove unneeded driver.bus assignment
  mtd: rawnand: marvell: Rename ->ecc_clk into ->core_clk
  mtd: rawnand: s3c2410: enhance the probe function error path
  mtd: rawnand: tango: fix probe function error path
  mtd: rawnand: sh_flctl: fix the probe function error path
  mtd: rawnand: omap2: fix the probe function error path
  mtd: rawnand: mxc: fix probe function error path
  mtd: rawnand: denali: fix probe function error path
  mtd: rawnand: davinci: fix probe function error path
  mtd: rawnand: cafe: fix probe function error path
  mtd: rawnand: brcmnand: fix probe function error path
  mtd: rawnand: sunxi: Stop supporting ECC_HW_SYNDROME mode
  mtd: rawnand: marvell: Fix clock resource by adding a register clock
  mtd: ftl: Use DIV_ROUND_UP()
  mtd: Fix some function description mismatches in mtdcore.c
  mtd: physmap_of: update struct map_info's swap as per map requirement
  dt-bindings: mtd-physmap: Add endianness supports
  ...

1 files changed, 6693 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
new file mode 100644
index 000000000000..72f3a89da513
--- /dev/null
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -0,0 +1,6693 @@
+/*
+ *  Overview:
+ *   This is the generic MTD driver for NAND flash devices. It should be
+ *   capable of working with almost all NAND chips currently available.
+ *
+ *	Additional technical information is available on
+ *	http://www.linux-mtd.infradead.org/doc/nand.html
+ *
+ *  Copyright (C) 2000 Steven J. Hill (sjhill@realitydiluted.com)
+ *		  2002-2006 Thomas Gleixner (tglx@linutronix.de)
+ *
+ *  Credits:
+ *	David Woodhouse for adding multichip support
+ *
+ *	Aleph One Ltd. and Toby Churchill Ltd. for supporting the
+ *	rework for 2K page size chips
+ *
+ *  TODO:
+ *	Enable cached programming for 2k page size chips
+ *	Check, if mtd->ecctype should be set to MTD_ECC_HW
+ *	if we have HW ECC support.
+ *	BBT table is not serialized, has to be fixed
+ *
+ * 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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/nmi.h>
+#include <linux/types.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/nand_bch.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+
+static int nand_get_device(struct mtd_info *mtd, int new_state);
+
+static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
+			     struct mtd_oob_ops *ops);
+
+/* Define default oob placement schemes for large and small page devices */
+static int nand_ooblayout_ecc_sp(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (section > 1)
+		return -ERANGE;
+
+	if (!section) {
+		oobregion->offset = 0;
+		if (mtd->oobsize == 16)
+			oobregion->length = 4;
+		else
+			oobregion->length = 3;
+	} else {
+		if (mtd->oobsize == 8)
+			return -ERANGE;
+
+		oobregion->offset = 6;
+		oobregion->length = ecc->total - 4;
+	}
+
+	return 0;
+}
+
+static int nand_ooblayout_free_sp(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oobregion)
+{
+	if (section > 1)
+		return -ERANGE;
+
+	if (mtd->oobsize == 16) {
+		if (section)
+			return -ERANGE;
+
+		oobregion->length = 8;
+		oobregion->offset = 8;
+	} else {
+		oobregion->length = 2;
+		if (!section)
+			oobregion->offset = 3;
+		else
+			oobregion->offset = 6;
+	}
+
+	return 0;
+}
+
+const struct mtd_ooblayout_ops nand_ooblayout_sp_ops = {
+	.ecc = nand_ooblayout_ecc_sp,
+	.free = nand_ooblayout_free_sp,
+};
+EXPORT_SYMBOL_GPL(nand_ooblayout_sp_ops);
+
+static int nand_ooblayout_ecc_lp(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (section || !ecc->total)
+		return -ERANGE;
+
+	oobregion->length = ecc->total;
+	oobregion->offset = mtd->oobsize - oobregion->length;
+
+	return 0;
+}
+
+static int nand_ooblayout_free_lp(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (section)
+		return -ERANGE;
+
+	oobregion->length = mtd->oobsize - ecc->total - 2;
+	oobregion->offset = 2;
+
+	return 0;
+}
+
+const struct mtd_ooblayout_ops nand_ooblayout_lp_ops = {
+	.ecc = nand_ooblayout_ecc_lp,
+	.free = nand_ooblayout_free_lp,
+};
+EXPORT_SYMBOL_GPL(nand_ooblayout_lp_ops);
+
+/*
+ * Support the old "large page" layout used for 1-bit Hamming ECC where ECC
+ * are placed at a fixed offset.
+ */
+static int nand_ooblayout_ecc_lp_hamming(struct mtd_info *mtd, int section,
+					 struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (section)
+		return -ERANGE;
+
+	switch (mtd->oobsize) {
+	case 64:
+		oobregion->offset = 40;
+		break;
+	case 128:
+		oobregion->offset = 80;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	oobregion->length = ecc->total;
+	if (oobregion->offset + oobregion->length > mtd->oobsize)
+		return -ERANGE;
+
+	return 0;
+}
+
+static int nand_ooblayout_free_lp_hamming(struct mtd_info *mtd, int section,
+					  struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int ecc_offset = 0;
+
+	if (section < 0 || section > 1)
+		return -ERANGE;
+
+	switch (mtd->oobsize) {
+	case 64:
+		ecc_offset = 40;
+		break;
+	case 128:
+		ecc_offset = 80;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (section == 0) {
+		oobregion->offset = 2;
+		oobregion->length = ecc_offset - 2;
+	} else {
+		oobregion->offset = ecc_offset + ecc->total;
+		oobregion->length = mtd->oobsize - oobregion->offset;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops nand_ooblayout_lp_hamming_ops = {
+	.ecc = nand_ooblayout_ecc_lp_hamming,
+	.free = nand_ooblayout_free_lp_hamming,
+};
+
+static int check_offs_len(struct mtd_info *mtd,
+					loff_t ofs, uint64_t len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret = 0;
+
+	/* Start address must align on block boundary */
+	if (ofs & ((1ULL << chip->phys_erase_shift) - 1)) {
+		pr_debug("%s: unaligned address\n", __func__);
+		ret = -EINVAL;
+	}
+
+	/* Length must align on block boundary */
+	if (len & ((1ULL << chip->phys_erase_shift) - 1)) {
+		pr_debug("%s: length not block aligned\n", __func__);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/**
+ * nand_release_device - [GENERIC] release chip
+ * @mtd: MTD device structure
+ *
+ * Release chip lock and wake up anyone waiting on the device.
+ */
+static void nand_release_device(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	/* Release the controller and the chip */
+	spin_lock(&chip->controller->lock);
+	chip->controller->active = NULL;
+	chip->state = FL_READY;
+	wake_up(&chip->controller->wq);
+	spin_unlock(&chip->controller->lock);
+}
+
+/**
+ * nand_read_byte - [DEFAULT] read one byte from the chip
+ * @mtd: MTD device structure
+ *
+ * Default read function for 8bit buswidth
+ */
+static uint8_t nand_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	return readb(chip->IO_ADDR_R);
+}
+
+/**
+ * nand_read_byte16 - [DEFAULT] read one byte endianness aware from the chip
+ * @mtd: MTD device structure
+ *
+ * Default read function for 16bit buswidth with endianness conversion.
+ *
+ */
+static uint8_t nand_read_byte16(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	return (uint8_t) cpu_to_le16(readw(chip->IO_ADDR_R));
+}
+
+/**
+ * nand_read_word - [DEFAULT] read one word from the chip
+ * @mtd: MTD device structure
+ *
+ * Default read function for 16bit buswidth without endianness conversion.
+ */
+static u16 nand_read_word(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	return readw(chip->IO_ADDR_R);
+}
+
+/**
+ * nand_select_chip - [DEFAULT] control CE line
+ * @mtd: MTD device structure
+ * @chipnr: chipnumber to select, -1 for deselect
+ *
+ * Default select function for 1 chip devices.
+ */
+static void nand_select_chip(struct mtd_info *mtd, int chipnr)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	switch (chipnr) {
+	case -1:
+		chip->cmd_ctrl(mtd, NAND_CMD_NONE, 0 | NAND_CTRL_CHANGE);
+		break;
+	case 0:
+		break;
+
+	default:
+		BUG();
+	}
+}
+
+/**
+ * nand_write_byte - [DEFAULT] write single byte to chip
+ * @mtd: MTD device structure
+ * @byte: value to write
+ *
+ * Default function to write a byte to I/O[7:0]
+ */
+static void nand_write_byte(struct mtd_info *mtd, uint8_t byte)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	chip->write_buf(mtd, &byte, 1);
+}
+
+/**
+ * nand_write_byte16 - [DEFAULT] write single byte to a chip with width 16
+ * @mtd: MTD device structure
+ * @byte: value to write
+ *
+ * Default function to write a byte to I/O[7:0] on a 16-bit wide chip.
+ */
+static void nand_write_byte16(struct mtd_info *mtd, uint8_t byte)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	uint16_t word = byte;
+
+	/*
+	 * It's not entirely clear what should happen to I/O[15:8] when writing
+	 * a byte. The ONFi spec (Revision 3.1; 2012-09-19, Section 2.16) reads:
+	 *
+	 *    When the host supports a 16-bit bus width, only data is
+	 *    transferred at the 16-bit width. All address and command line
+	 *    transfers shall use only the lower 8-bits of the data bus. During
+	 *    command transfers, the host may place any value on the upper
+	 *    8-bits of the data bus. During address transfers, the host shall
+	 *    set the upper 8-bits of the data bus to 00h.
+	 *
+	 * One user of the write_byte callback is nand_set_features. The
+	 * four parameters are specified to be written to I/O[7:0], but this is
+	 * neither an address nor a command transfer. Let's assume a 0 on the
+	 * upper I/O lines is OK.
+	 */
+	chip->write_buf(mtd, (uint8_t *)&word, 2);
+}
+
+/**
+ * nand_write_buf - [DEFAULT] write buffer to chip
+ * @mtd: MTD device structure
+ * @buf: data buffer
+ * @len: number of bytes to write
+ *
+ * Default write function for 8bit buswidth.
+ */
+static void nand_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	iowrite8_rep(chip->IO_ADDR_W, buf, len);
+}
+
+/**
+ * nand_read_buf - [DEFAULT] read chip data into buffer
+ * @mtd: MTD device structure
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ *
+ * Default read function for 8bit buswidth.
+ */
+static void nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	ioread8_rep(chip->IO_ADDR_R, buf, len);
+}
+
+/**
+ * nand_write_buf16 - [DEFAULT] write buffer to chip
+ * @mtd: MTD device structure
+ * @buf: data buffer
+ * @len: number of bytes to write
+ *
+ * Default write function for 16bit buswidth.
+ */
+static void nand_write_buf16(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	u16 *p = (u16 *) buf;
+
+	iowrite16_rep(chip->IO_ADDR_W, p, len >> 1);
+}
+
+/**
+ * nand_read_buf16 - [DEFAULT] read chip data into buffer
+ * @mtd: MTD device structure
+ * @buf: buffer to store date
+ * @len: number of bytes to read
+ *
+ * Default read function for 16bit buswidth.
+ */
+static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	u16 *p = (u16 *) buf;
+
+	ioread16_rep(chip->IO_ADDR_R, p, len >> 1);
+}
+
+/**
+ * nand_block_bad - [DEFAULT] Read bad block marker from the chip
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ *
+ * Check, if the block is bad.
+ */
+static int nand_block_bad(struct mtd_info *mtd, loff_t ofs)
+{
+	int page, page_end, res;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	u8 bad;
+
+	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
+		ofs += mtd->erasesize - mtd->writesize;
+
+	page = (int)(ofs >> chip->page_shift) & chip->pagemask;
+	page_end = page + (chip->bbt_options & NAND_BBT_SCAN2NDPAGE ? 2 : 1);
+
+	for (; page < page_end; page++) {
+		res = chip->ecc.read_oob(mtd, chip, page);
+		if (res)
+			return res;
+
+		bad = chip->oob_poi[chip->badblockpos];
+
+		if (likely(chip->badblockbits == 8))
+			res = bad != 0xFF;
+		else
+			res = hweight8(bad) < chip->badblockbits;
+		if (res)
+			return res;
+	}
+
+	return 0;
+}
+
+/**
+ * nand_default_block_markbad - [DEFAULT] mark a block bad via bad block marker
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ *
+ * This is the default implementation, which can be overridden by a hardware
+ * specific driver. It provides the details for writing a bad block marker to a
+ * block.
+ */
+static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtd_oob_ops ops;
+	uint8_t buf[2] = { 0, 0 };
+	int ret = 0, res, i = 0;
+
+	memset(&ops, 0, sizeof(ops));
+	ops.oobbuf = buf;
+	ops.ooboffs = chip->badblockpos;
+	if (chip->options & NAND_BUSWIDTH_16) {
+		ops.ooboffs &= ~0x01;
+		ops.len = ops.ooblen = 2;
+	} else {
+		ops.len = ops.ooblen = 1;
+	}
+	ops.mode = MTD_OPS_PLACE_OOB;
+
+	/* Write to first/last page(s) if necessary */
+	if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
+		ofs += mtd->erasesize - mtd->writesize;
+	do {
+		res = nand_do_write_oob(mtd, ofs, &ops);
+		if (!ret)
+			ret = res;
+
+		i++;
+		ofs += mtd->writesize;
+	} while ((chip->bbt_options & NAND_BBT_SCAN2NDPAGE) && i < 2);
+
+	return ret;
+}
+
+/**
+ * nand_block_markbad_lowlevel - mark a block bad
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ *
+ * This function performs the generic NAND bad block marking steps (i.e., bad
+ * block table(s) and/or marker(s)). We only allow the hardware driver to
+ * specify how to write bad block markers to OOB (chip->block_markbad).
+ *
+ * We try operations in the following order:
+ *
+ *  (1) erase the affected block, to allow OOB marker to be written cleanly
+ *  (2) write bad block marker to OOB area of affected block (unless flag
+ *      NAND_BBT_NO_OOB_BBM is present)
+ *  (3) update the BBT
+ *
+ * Note that we retain the first error encountered in (2) or (3), finish the
+ * procedures, and dump the error in the end.
+*/
+static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int res, ret = 0;
+
+	if (!(chip->bbt_options & NAND_BBT_NO_OOB_BBM)) {
+		struct erase_info einfo;
+
+		/* Attempt erase before marking OOB */
+		memset(&einfo, 0, sizeof(einfo));
+		einfo.addr = ofs;
+		einfo.len = 1ULL << chip->phys_erase_shift;
+		nand_erase_nand(mtd, &einfo, 0);
+
+		/* Write bad block marker to OOB */
+		nand_get_device(mtd, FL_WRITING);
+		ret = chip->block_markbad(mtd, ofs);
+		nand_release_device(mtd);
+	}
+
+	/* Mark block bad in BBT */
+	if (chip->bbt) {
+		res = nand_markbad_bbt(mtd, ofs);
+		if (!ret)
+			ret = res;
+	}
+
+	if (!ret)
+		mtd->ecc_stats.badblocks++;
+
+	return ret;
+}
+
+/**
+ * nand_check_wp - [GENERIC] check if the chip is write protected
+ * @mtd: MTD device structure
+ *
+ * Check, if the device is write protected. The function expects, that the
+ * device is already selected.
+ */
+static int nand_check_wp(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	u8 status;
+	int ret;
+
+	/* Broken xD cards report WP despite being writable */
+	if (chip->options & NAND_BROKEN_XD)
+		return 0;
+
+	/* Check the WP bit */
+	ret = nand_status_op(chip, &status);
+	if (ret)
+		return ret;
+
+	return status & NAND_STATUS_WP ? 0 : 1;
+}
+
+/**
+ * nand_block_isreserved - [GENERIC] Check if a block is marked reserved.
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ *
+ * Check if the block is marked as reserved.
+ */
+static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (!chip->bbt)
+		return 0;
+	/* Return info from the table */
+	return nand_isreserved_bbt(mtd, ofs);
+}
+
+/**
+ * nand_block_checkbad - [GENERIC] Check if a block is marked bad
+ * @mtd: MTD device structure
+ * @ofs: offset from device start
+ * @allowbbt: 1, if its allowed to access the bbt area
+ *
+ * Check, if the block is bad. Either by reading the bad block table or
+ * calling of the scan function.
+ */
+static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int allowbbt)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (!chip->bbt)
+		return chip->block_bad(mtd, ofs);
+
+	/* Return info from the table */
+	return nand_isbad_bbt(mtd, ofs, allowbbt);
+}
+
+/**
+ * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
+ * @mtd: MTD device structure
+ * @timeo: Timeout
+ *
+ * Helper function for nand_wait_ready used when needing to wait in interrupt
+ * context.
+ */
+static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int i;
+
+	/* Wait for the device to get ready */
+	for (i = 0; i < timeo; i++) {
+		if (chip->dev_ready(mtd))
+			break;
+		touch_softlockup_watchdog();
+		mdelay(1);
+	}
+}
+
+/**
+ * nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
+ * @mtd: MTD device structure
+ *
+ * Wait for the ready pin after a command, and warn if a timeout occurs.
+ */
+void nand_wait_ready(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	unsigned long timeo = 400;
+
+	if (in_interrupt() || oops_in_progress)
+		return panic_nand_wait_ready(mtd, timeo);
+
+	/* Wait until command is processed or timeout occurs */
+	timeo = jiffies + msecs_to_jiffies(timeo);
+	do {
+		if (chip->dev_ready(mtd))
+			return;
+		cond_resched();
+	} while (time_before(jiffies, timeo));
+
+	if (!chip->dev_ready(mtd))
+		pr_warn_ratelimited("timeout while waiting for chip to become ready\n");
+}
+EXPORT_SYMBOL_GPL(nand_wait_ready);
+
+/**
+ * nand_wait_status_ready - [GENERIC] Wait for the ready status after commands.
+ * @mtd: MTD device structure
+ * @timeo: Timeout in ms
+ *
+ * Wait for status ready (i.e. command done) or timeout.
+ */
+static void nand_wait_status_ready(struct mtd_info *mtd, unsigned long timeo)
+{
+	register struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret;
+
+	timeo = jiffies + msecs_to_jiffies(timeo);
+	do {
+		u8 status;
+
+		ret = nand_read_data_op(chip, &status, sizeof(status), true);
+		if (ret)
+			return;
+
+		if (status & NAND_STATUS_READY)
+			break;
+		touch_softlockup_watchdog();
+	} while (time_before(jiffies, timeo));
+};
+
+/**
+ * nand_soft_waitrdy - Poll STATUS reg until RDY bit is set to 1
+ * @chip: NAND chip structure
+ * @timeout_ms: Timeout in ms
+ *
+ * Poll the STATUS register using ->exec_op() until the RDY bit becomes 1.
+ * If that does not happen whitin the specified timeout, -ETIMEDOUT is
+ * returned.
+ *
+ * This helper is intended to be used when the controller does not have access
+ * to the NAND R/B pin.
+ *
+ * Be aware that calling this helper from an ->exec_op() implementation means
+ * ->exec_op() must be re-entrant.
+ *
+ * Return 0 if the NAND chip is ready, a negative error otherwise.
+ */
+int nand_soft_waitrdy(struct nand_chip *chip, unsigned long timeout_ms)
+{
+	u8 status = 0;
+	int ret;
+
+	if (!chip->exec_op)
+		return -ENOTSUPP;
+
+	ret = nand_status_op(chip, NULL);
+	if (ret)
+		return ret;
+
+	timeout_ms = jiffies + msecs_to_jiffies(timeout_ms);
+	do {
+		ret = nand_read_data_op(chip, &status, sizeof(status), true);
+		if (ret)
+			break;
+
+		if (status & NAND_STATUS_READY)
+			break;
+
+		/*
+		 * Typical lowest execution time for a tR on most NANDs is 10us,
+		 * use this as polling delay before doing something smarter (ie.
+		 * deriving a delay from the timeout value, timeout_ms/ratio).
+		 */
+		udelay(10);
+	} while	(time_before(jiffies, timeout_ms));
+
+	/*
+	 * We have to exit READ_STATUS mode in order to read real data on the
+	 * bus in case the WAITRDY instruction is preceding a DATA_IN
+	 * instruction.
+	 */
+	nand_exit_status_op(chip);
+
+	if (ret)
+		return ret;
+
+	return status & NAND_STATUS_READY ? 0 : -ETIMEDOUT;
+};
+EXPORT_SYMBOL_GPL(nand_soft_waitrdy);
+
+/**
+ * nand_command - [DEFAULT] Send command to NAND device
+ * @mtd: MTD device structure
+ * @command: the command to be sent
+ * @column: the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device. This function is used for small page devices
+ * (512 Bytes per page).
+ */
+static void nand_command(struct mtd_info *mtd, unsigned int command,
+			 int column, int page_addr)
+{
+	register struct nand_chip *chip = mtd_to_nand(mtd);
+	int ctrl = NAND_CTRL_CLE | NAND_CTRL_CHANGE;
+
+	/* Write out the command to the device */
+	if (command == NAND_CMD_SEQIN) {
+		int readcmd;
+
+		if (column >= mtd->writesize) {
+			/* OOB area */
+			column -= mtd->writesize;
+			readcmd = NAND_CMD_READOOB;
+		} else if (column < 256) {
+			/* First 256 bytes --> READ0 */
+			readcmd = NAND_CMD_READ0;
+		} else {
+			column -= 256;
+			readcmd = NAND_CMD_READ1;
+		}
+		chip->cmd_ctrl(mtd, readcmd, ctrl);
+		ctrl &= ~NAND_CTRL_CHANGE;
+	}
+	if (command != NAND_CMD_NONE)
+		chip->cmd_ctrl(mtd, command, ctrl);
+
+	/* Address cycle, when necessary */
+	ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE;
+	/* Serially input address */
+	if (column != -1) {
+		/* Adjust columns for 16 bit buswidth */
+		if (chip->options & NAND_BUSWIDTH_16 &&
+				!nand_opcode_8bits(command))
+			column >>= 1;
+		chip->cmd_ctrl(mtd, column, ctrl);
+		ctrl &= ~NAND_CTRL_CHANGE;
+	}
+	if (page_addr != -1) {
+		chip->cmd_ctrl(mtd, page_addr, ctrl);
+		ctrl &= ~NAND_CTRL_CHANGE;
+		chip->cmd_ctrl(mtd, page_addr >> 8, ctrl);
+		if (chip->options & NAND_ROW_ADDR_3)
+			chip->cmd_ctrl(mtd, page_addr >> 16, ctrl);
+	}
+	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
+
+	/*
+	 * Program and erase have their own busy handlers status and sequential
+	 * in needs no delay
+	 */
+	switch (command) {
+
+	case NAND_CMD_NONE:
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_STATUS:
+	case NAND_CMD_READID:
+	case NAND_CMD_SET_FEATURES:
+		return;
+
+	case NAND_CMD_RESET:
+		if (chip->dev_ready)
+			break;
+		udelay(chip->chip_delay);
+		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
+			       NAND_CTRL_CLE | NAND_CTRL_CHANGE);
+		chip->cmd_ctrl(mtd,
+			       NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
+		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
+		nand_wait_status_ready(mtd, 250);
+		return;
+
+		/* This applies to read commands */
+	case NAND_CMD_READ0:
+		/*
+		 * READ0 is sometimes used to exit GET STATUS mode. When this
+		 * is the case no address cycles are requested, and we can use
+		 * this information to detect that we should not wait for the
+		 * device to be ready.
+		 */
+		if (column == -1 && page_addr == -1)
+			return;
+
+	default:
+		/*
+		 * If we don't have access to the busy pin, we apply the given
+		 * command delay
+		 */
+		if (!chip->dev_ready) {
+			udelay(chip->chip_delay);
+			return;
+		}
+	}
+	/*
+	 * Apply this short delay always to ensure that we do wait tWB in
+	 * any case on any machine.
+	 */
+	ndelay(100);
+
+	nand_wait_ready(mtd);
+}
+
+static void nand_ccs_delay(struct nand_chip *chip)
+{
+	/*
+	 * The controller already takes care of waiting for tCCS when the RNDIN
+	 * or RNDOUT command is sent, return directly.
+	 */
+	if (!(chip->options & NAND_WAIT_TCCS))
+		return;
+
+	/*
+	 * Wait tCCS_min if it is correctly defined, otherwise wait 500ns
+	 * (which should be safe for all NANDs).
+	 */
+	if (chip->setup_data_interface)
+		ndelay(chip->data_interface.timings.sdr.tCCS_min / 1000);
+	else
+		ndelay(500);
+}
+
+/**
+ * nand_command_lp - [DEFAULT] Send command to NAND large page device
+ * @mtd: MTD device structure
+ * @command: the command to be sent
+ * @column: the column address for this command, -1 if none
+ * @page_addr: the page address for this command, -1 if none
+ *
+ * Send command to NAND device. This is the version for the new large page
+ * devices. We don't have the separate regions as we have in the small page
+ * devices. We must emulate NAND_CMD_READOOB to keep the code compatible.
+ */
+static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
+			    int column, int page_addr)
+{
+	register struct nand_chip *chip = mtd_to_nand(mtd);
+
+	/* Emulate NAND_CMD_READOOB */
+	if (command == NAND_CMD_READOOB) {
+		column += mtd->writesize;
+		command = NAND_CMD_READ0;
+	}
+
+	/* Command latch cycle */
+	if (command != NAND_CMD_NONE)
+		chip->cmd_ctrl(mtd, command,
+			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+
+	if (column != -1 || page_addr != -1) {
+		int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE;
+
+		/* Serially input address */
+		if (column != -1) {
+			/* Adjust columns for 16 bit buswidth */
+			if (chip->options & NAND_BUSWIDTH_16 &&
+					!nand_opcode_8bits(command))
+				column >>= 1;
+			chip->cmd_ctrl(mtd, column, ctrl);
+			ctrl &= ~NAND_CTRL_CHANGE;
+
+			/* Only output a single addr cycle for 8bits opcodes. */
+			if (!nand_opcode_8bits(command))
+				chip->cmd_ctrl(mtd, column >> 8, ctrl);
+		}
+		if (page_addr != -1) {
+			chip->cmd_ctrl(mtd, page_addr, ctrl);
+			chip->cmd_ctrl(mtd, page_addr >> 8,
+				       NAND_NCE | NAND_ALE);
+			if (chip->options & NAND_ROW_ADDR_3)
+				chip->cmd_ctrl(mtd, page_addr >> 16,
+					       NAND_NCE | NAND_ALE);
+		}
+	}
+	chip->cmd_ctrl(mtd, NAND_CMD_NONE, NAND_NCE | NAND_CTRL_CHANGE);
+
+	/*
+	 * Program and erase have their own busy handlers status, sequential
+	 * in and status need no delay.
+	 */
+	switch (command) {
+
+	case NAND_CMD_NONE:
+	case NAND_CMD_CACHEDPROG:
+	case NAND_CMD_PAGEPROG:
+	case NAND_CMD_ERASE1:
+	case NAND_CMD_ERASE2:
+	case NAND_CMD_SEQIN:
+	case NAND_CMD_STATUS:
+	case NAND_CMD_READID:
+	case NAND_CMD_SET_FEATURES:
+		return;
+
+	case NAND_CMD_RNDIN:
+		nand_ccs_delay(chip);
+		return;
+
+	case NAND_CMD_RESET:
+		if (chip->dev_ready)
+			break;
+		udelay(chip->chip_delay);
+		chip->cmd_ctrl(mtd, NAND_CMD_STATUS,
+			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
+			       NAND_NCE | NAND_CTRL_CHANGE);
+		/* EZ-NAND can take upto 250ms as per ONFi v4.0 */
+		nand_wait_status_ready(mtd, 250);
+		return;
+
+	case NAND_CMD_RNDOUT:
+		/* No ready / busy check necessary */
+		chip->cmd_ctrl(mtd, NAND_CMD_RNDOUTSTART,
+			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
+			       NAND_NCE | NAND_CTRL_CHANGE);
+
+		nand_ccs_delay(chip);
+		return;
+
+	case NAND_CMD_READ0:
+		/*
+		 * READ0 is sometimes used to exit GET STATUS mode. When this
+		 * is the case no address cycles are requested, and we can use
+		 * this information to detect that READSTART should not be
+		 * issued.
+		 */
+		if (column == -1 && page_addr == -1)
+			return;
+
+		chip->cmd_ctrl(mtd, NAND_CMD_READSTART,
+			       NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE);
+		chip->cmd_ctrl(mtd, NAND_CMD_NONE,
+			       NAND_NCE | NAND_CTRL_CHANGE);
+
+		/* This applies to read commands */
+	default:
+		/*
+		 * If we don't have access to the busy pin, we apply the given
+		 * command delay.
+		 */
+		if (!chip->dev_ready) {
+			udelay(chip->chip_delay);
+			return;
+		}
+	}
+
+	/*
+	 * Apply this short delay always to ensure that we do wait tWB in
+	 * any case on any machine.
+	 */
+	ndelay(100);
+
+	nand_wait_ready(mtd);
+}
+
+/**
+ * panic_nand_get_device - [GENERIC] Get chip for selected access
+ * @chip: the nand chip descriptor
+ * @mtd: MTD device structure
+ * @new_state: the state which is requested
+ *
+ * Used when in panic, no locks are taken.
+ */
+static void panic_nand_get_device(struct nand_chip *chip,
+		      struct mtd_info *mtd, int new_state)
+{
+	/* Hardware controller shared among independent devices */
+	chip->controller->active = chip;
+	chip->state = new_state;
+}
+
+/**
+ * nand_get_device - [GENERIC] Get chip for selected access
+ * @mtd: MTD device structure
+ * @new_state: the state which is requested
+ *
+ * Get the device and lock it for exclusive access
+ */
+static int
+nand_get_device(struct mtd_info *mtd, int new_state)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	spinlock_t *lock = &chip->controller->lock;
+	wait_queue_head_t *wq = &chip->controller->wq;
+	DECLARE_WAITQUEUE(wait, current);
+retry:
+	spin_lock(lock);
+
+	/* Hardware controller shared among independent devices */
+	if (!chip->controller->active)
+		chip->controller->active = chip;
+
+	if (chip->controller->active == chip && chip->state == FL_READY) {
+		chip->state = new_state;
+		spin_unlock(lock);
+		return 0;
+	}
+	if (new_state == FL_PM_SUSPENDED) {
+		if (chip->controller->active->state == FL_PM_SUSPENDED) {
+			chip->state = FL_PM_SUSPENDED;
+			spin_unlock(lock);
+			return 0;
+		}
+	}
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	add_wait_queue(wq, &wait);
+	spin_unlock(lock);
+	schedule();
+	remove_wait_queue(wq, &wait);
+	goto retry;
+}
+
+/**
+ * panic_nand_wait - [GENERIC] wait until the command is done
+ * @mtd: MTD device structure
+ * @chip: NAND chip structure
+ * @timeo: timeout
+ *
+ * Wait for command done. This is a helper function for nand_wait used when
+ * we are in interrupt context. May happen when in panic and trying to write
+ * an oops through mtdoops.
+ */
+static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
+			    unsigned long timeo)
+{
+	int i;
+	for (i = 0; i < timeo; i++) {
+		if (chip->dev_ready) {
+			if (chip->dev_ready(mtd))
+				break;
+		} else {
+			int ret;
+			u8 status;
+
+			ret = nand_read_data_op(chip, &status, sizeof(status),
+						true);
+			if (ret)
+				return;
+
+			if (status & NAND_STATUS_READY)
+				break;
+		}
+		mdelay(1);
+	}
+}
+
+/**
+ * nand_wait - [DEFAULT] wait until the command is done
+ * @mtd: MTD device structure
+ * @chip: NAND chip structure
+ *
+ * Wait for command done. This applies to erase and program only.
+ */
+static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
+{
+
+	unsigned long timeo = 400;
+	u8 status;
+	int ret;
+
+	/*
+	 * Apply this short delay always to ensure that we do wait tWB in any
+	 * case on any machine.
+	 */
+	ndelay(100);
+
+	ret = nand_status_op(chip, NULL);
+	if (ret)
+		return ret;
+
+	if (in_interrupt() || oops_in_progress)
+		panic_nand_wait(mtd, chip, timeo);
+	else {
+		timeo = jiffies + msecs_to_jiffies(timeo);
+		do {
+			if (chip->dev_ready) {
+				if (chip->dev_ready(mtd))
+					break;
+			} else {
+				ret = nand_read_data_op(chip, &status,
+							sizeof(status), true);
+				if (ret)
+					return ret;
+
+				if (status & NAND_STATUS_READY)
+					break;
+			}
+			cond_resched();
+		} while (time_before(jiffies, timeo));
+	}
+
+	ret = nand_read_data_op(chip, &status, sizeof(status), true);
+	if (ret)
+		return ret;
+
+	/* This can happen if in case of timeout or buggy dev_ready */
+	WARN_ON(!(status & NAND_STATUS_READY));
+	return status;
+}
+
+static bool nand_supports_get_features(struct nand_chip *chip, int addr)
+{
+	return (chip->parameters.supports_set_get_features &&
+		test_bit(addr, chip->parameters.get_feature_list));
+}
+
+static bool nand_supports_set_features(struct nand_chip *chip, int addr)
+{
+	return (chip->parameters.supports_set_get_features &&
+		test_bit(addr, chip->parameters.set_feature_list));
+}
+
+/**
+ * nand_get_features - wrapper to perform a GET_FEATURE
+ * @chip: NAND chip info structure
+ * @addr: feature address
+ * @subfeature_param: the subfeature parameters, a four bytes array
+ *
+ * Returns 0 for success, a negative error otherwise. Returns -ENOTSUPP if the
+ * operation cannot be handled.
+ */
+int nand_get_features(struct nand_chip *chip, int addr,
+		      u8 *subfeature_param)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (!nand_supports_get_features(chip, addr))
+		return -ENOTSUPP;
+
+	return chip->get_features(mtd, chip, addr, subfeature_param);
+}
+EXPORT_SYMBOL_GPL(nand_get_features);
+
+/**
+ * nand_set_features - wrapper to perform a SET_FEATURE
+ * @chip: NAND chip info structure
+ * @addr: feature address
+ * @subfeature_param: the subfeature parameters, a four bytes array
+ *
+ * Returns 0 for success, a negative error otherwise. Returns -ENOTSUPP if the
+ * operation cannot be handled.
+ */
+int nand_set_features(struct nand_chip *chip, int addr,
+		      u8 *subfeature_param)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (!nand_supports_set_features(chip, addr))
+		return -ENOTSUPP;
+
+	return chip->set_features(mtd, chip, addr, subfeature_param);
+}
+EXPORT_SYMBOL_GPL(nand_set_features);
+
+/**
+ * nand_reset_data_interface - Reset data interface and timings
+ * @chip: The NAND chip
+ * @chipnr: Internal die id
+ *
+ * Reset the Data interface and timings to ONFI mode 0.
+ *
+ * Returns 0 for success or negative error code otherwise.
+ */
+static int nand_reset_data_interface(struct nand_chip *chip, int chipnr)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int ret;
+
+	if (!chip->setup_data_interface)
+		return 0;
+
+	/*
+	 * The ONFI specification says:
+	 * "
+	 * To transition from NV-DDR or NV-DDR2 to the SDR data
+	 * interface, the host shall use the Reset (FFh) command
+	 * using SDR timing mode 0. A device in any timing mode is
+	 * required to recognize Reset (FFh) command issued in SDR
+	 * timing mode 0.
+	 * "
+	 *
+	 * Configure the data interface in SDR mode and set the
+	 * timings to timing mode 0.
+	 */
+
+	onfi_fill_data_interface(chip, NAND_SDR_IFACE, 0);
+	ret = chip->setup_data_interface(mtd, chipnr, &chip->data_interface);
+	if (ret)
+		pr_err("Failed to configure data interface to SDR timing mode 0\n");
+
+	return ret;
+}
+
+/**
+ * nand_setup_data_interface - Setup the best data interface and timings
+ * @chip: The NAND chip
+ * @chipnr: Internal die id
+ *
+ * Find and configure the best data interface and NAND timings supported by
+ * the chip and the driver.
+ * First tries to retrieve supported timing modes from ONFI information,
+ * and if the NAND chip does not support ONFI, relies on the
+ * ->onfi_timing_mode_default specified in the nand_ids table.
+ *
+ * Returns 0 for success or negative error code otherwise.
+ */
+static int nand_setup_data_interface(struct nand_chip *chip, int chipnr)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u8 tmode_param[ONFI_SUBFEATURE_PARAM_LEN] = {
+		chip->onfi_timing_mode_default,
+	};
+	int ret;
+
+	if (!chip->setup_data_interface)
+		return 0;
+
+	/* Change the mode on the chip side (if supported by the NAND chip) */
+	if (nand_supports_set_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE)) {
+		chip->select_chip(mtd, chipnr);
+		ret = nand_set_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE,
+					tmode_param);
+		chip->select_chip(mtd, -1);
+		if (ret)
+			return ret;
+	}
+
+	/* Change the mode on the controller side */
+	ret = chip->setup_data_interface(mtd, chipnr, &chip->data_interface);
+	if (ret)
+		return ret;
+
+	/* Check the mode has been accepted by the chip, if supported */
+	if (!nand_supports_get_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE))
+		return 0;
+
+	memset(tmode_param, 0, ONFI_SUBFEATURE_PARAM_LEN);
+	chip->select_chip(mtd, chipnr);
+	ret = nand_get_features(chip, ONFI_FEATURE_ADDR_TIMING_MODE,
+				tmode_param);
+	chip->select_chip(mtd, -1);
+	if (ret)
+		goto err_reset_chip;
+
+	if (tmode_param[0] != chip->onfi_timing_mode_default) {
+		pr_warn("timing mode %d not acknowledged by the NAND chip\n",
+			chip->onfi_timing_mode_default);
+		goto err_reset_chip;
+	}
+
+	return 0;
+
+err_reset_chip:
+	/*
+	 * Fallback to mode 0 if the chip explicitly did not ack the chosen
+	 * timing mode.
+	 */
+	nand_reset_data_interface(chip, chipnr);
+	chip->select_chip(mtd, chipnr);
+	nand_reset_op(chip);
+	chip->select_chip(mtd, -1);
+
+	return ret;
+}
+
+/**
+ * nand_init_data_interface - find the best data interface and timings
+ * @chip: The NAND chip
+ *
+ * Find the best data interface and NAND timings supported by the chip
+ * and the driver.
+ * First tries to retrieve supported timing modes from ONFI information,
+ * and if the NAND chip does not support ONFI, relies on the
+ * ->onfi_timing_mode_default specified in the nand_ids table. After this
+ * function nand_chip->data_interface is initialized with the best timing mode
+ * available.
+ *
+ * Returns 0 for success or negative error code otherwise.
+ */
+static int nand_init_data_interface(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int modes, mode, ret;
+
+	if (!chip->setup_data_interface)
+		return 0;
+
+	/*
+	 * First try to identify the best timings from ONFI parameters and
+	 * if the NAND does not support ONFI, fallback to the default ONFI
+	 * timing mode.
+	 */
+	modes = onfi_get_async_timing_mode(chip);
+	if (modes == ONFI_TIMING_MODE_UNKNOWN) {
+		if (!chip->onfi_timing_mode_default)
+			return 0;
+
+		modes = GENMASK(chip->onfi_timing_mode_default, 0);
+	}
+
+
+	for (mode = fls(modes) - 1; mode >= 0; mode--) {
+		ret = onfi_fill_data_interface(chip, NAND_SDR_IFACE, mode);
+		if (ret)
+			continue;
+
+		/*
+		 * Pass NAND_DATA_IFACE_CHECK_ONLY to only check if the
+		 * controller supports the requested timings.
+		 */
+		ret = chip->setup_data_interface(mtd,
+						 NAND_DATA_IFACE_CHECK_ONLY,
+						 &chip->data_interface);
+		if (!ret) {
+			chip->onfi_timing_mode_default = mode;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * nand_fill_column_cycles - fill the column cycles of an address
+ * @chip: The NAND chip
+ * @addrs: Array of address cycles to fill
+ * @offset_in_page: The offset in the page
+ *
+ * Fills the first or the first two bytes of the @addrs field depending
+ * on the NAND bus width and the page size.
+ *
+ * Returns the number of cycles needed to encode the column, or a negative
+ * error code in case one of the arguments is invalid.
+ */
+static int nand_fill_column_cycles(struct nand_chip *chip, u8 *addrs,
+				   unsigned int offset_in_page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	/* Make sure the offset is less than the actual page size. */
+	if (offset_in_page > mtd->writesize + mtd->oobsize)
+		return -EINVAL;
+
+	/*
+	 * On small page NANDs, there's a dedicated command to access the OOB
+	 * area, and the column address is relative to the start of the OOB
+	 * area, not the start of the page. Asjust the address accordingly.
+	 */
+	if (mtd->writesize <= 512 && offset_in_page >= mtd->writesize)
+		offset_in_page -= mtd->writesize;
+
+	/*
+	 * The offset in page is expressed in bytes, if the NAND bus is 16-bit
+	 * wide, then it must be divided by 2.
+	 */
+	if (chip->options & NAND_BUSWIDTH_16) {
+		if (WARN_ON(offset_in_page % 2))
+			return -EINVAL;
+
+		offset_in_page /= 2;
+	}
+
+	addrs[0] = offset_in_page;
+
+	/*
+	 * Small page NANDs use 1 cycle for the columns, while large page NANDs
+	 * need 2
+	 */
+	if (mtd->writesize <= 512)
+		return 1;
+
+	addrs[1] = offset_in_page >> 8;
+
+	return 2;
+}
+
+static int nand_sp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
+				     unsigned int offset_in_page, void *buf,
+				     unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_sdr_timings *sdr =
+		nand_get_sdr_timings(&chip->data_interface);
+	u8 addrs[4];
+	struct nand_op_instr instrs[] = {
+		NAND_OP_CMD(NAND_CMD_READ0, 0),
+		NAND_OP_ADDR(3, addrs, PSEC_TO_NSEC(sdr->tWB_max)),
+		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tR_max),
+				 PSEC_TO_NSEC(sdr->tRR_min)),
+		NAND_OP_DATA_IN(len, buf, 0),
+	};
+	struct nand_operation op = NAND_OPERATION(instrs);
+	int ret;
+
+	/* Drop the DATA_IN instruction if len is set to 0. */
+	if (!len)
+		op.ninstrs--;
+
+	if (offset_in_page >= mtd->writesize)
+		instrs[0].ctx.cmd.opcode = NAND_CMD_READOOB;
+	else if (offset_in_page >= 256 &&
+		 !(chip->options & NAND_BUSWIDTH_16))
+		instrs[0].ctx.cmd.opcode = NAND_CMD_READ1;
+
+	ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
+	if (ret < 0)
+		return ret;
+
+	addrs[1] = page;
+	addrs[2] = page >> 8;
+
+	if (chip->options & NAND_ROW_ADDR_3) {
+		addrs[3] = page >> 16;
+		instrs[1].ctx.addr.naddrs++;
+	}
+
+	return nand_exec_op(chip, &op);
+}
+
+static int nand_lp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
+				     unsigned int offset_in_page, void *buf,
+				     unsigned int len)
+{
+	const struct nand_sdr_timings *sdr =
+		nand_get_sdr_timings(&chip->data_interface);
+	u8 addrs[5];
+	struct nand_op_instr instrs[] = {
+		NAND_OP_CMD(NAND_CMD_READ0, 0),
+		NAND_OP_ADDR(4, addrs, 0),
+		NAND_OP_CMD(NAND_CMD_READSTART, PSEC_TO_NSEC(sdr->tWB_max)),
+		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tR_max),
+				 PSEC_TO_NSEC(sdr->tRR_min)),
+		NAND_OP_DATA_IN(len, buf, 0),
+	};
+	struct nand_operation op = NAND_OPERATION(instrs);
+	int ret;
+
+	/* Drop the DATA_IN instruction if len is set to 0. */
+	if (!len)
+		op.ninstrs--;
+
+	ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
+	if (ret < 0)
+		return ret;
+
+	addrs[2] = page;
+	addrs[3] = page >> 8;
+
+	if (chip->options & NAND_ROW_ADDR_3) {
+		addrs[4] = page >> 16;
+		instrs[1].ctx.addr.naddrs++;
+	}
+
+	return nand_exec_op(chip, &op);
+}
+
+/**
+ * nand_read_page_op - Do a READ PAGE operation
+ * @chip: The NAND chip
+ * @page: page to read
+ * @offset_in_page: offset within the page
+ * @buf: buffer used to store the data
+ * @len: length of the buffer
+ *
+ * This function issues a READ PAGE operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_read_page_op(struct nand_chip *chip, unsigned int page,
+		      unsigned int offset_in_page, void *buf, unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
+		return -EINVAL;
+
+	if (chip->exec_op) {
+		if (mtd->writesize > 512)
+			return nand_lp_exec_read_page_op(chip, page,
+							 offset_in_page, buf,
+							 len);
+
+		return nand_sp_exec_read_page_op(chip, page, offset_in_page,
+						 buf, len);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_READ0, offset_in_page, page);
+	if (len)
+		chip->read_buf(mtd, buf, len);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_read_page_op);
+
+/**
+ * nand_read_param_page_op - Do a READ PARAMETER PAGE operation
+ * @chip: The NAND chip
+ * @page: parameter page to read
+ * @buf: buffer used to store the data
+ * @len: length of the buffer
+ *
+ * This function issues a READ PARAMETER PAGE operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static int nand_read_param_page_op(struct nand_chip *chip, u8 page, void *buf,
+				   unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int i;
+	u8 *p = buf;
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_PARAM, 0),
+			NAND_OP_ADDR(1, &page, PSEC_TO_NSEC(sdr->tWB_max)),
+			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tR_max),
+					 PSEC_TO_NSEC(sdr->tRR_min)),
+			NAND_OP_8BIT_DATA_IN(len, buf, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		/* Drop the DATA_IN instruction if len is set to 0. */
+		if (!len)
+			op.ninstrs--;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_PARAM, page, -1);
+	for (i = 0; i < len; i++)
+		p[i] = chip->read_byte(mtd);
+
+	return 0;
+}
+
+/**
+ * nand_change_read_column_op - Do a CHANGE READ COLUMN operation
+ * @chip: The NAND chip
+ * @offset_in_page: offset within the page
+ * @buf: buffer used to store the data
+ * @len: length of the buffer
+ * @force_8bit: force 8-bit bus access
+ *
+ * This function issues a CHANGE READ COLUMN operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_change_read_column_op(struct nand_chip *chip,
+			       unsigned int offset_in_page, void *buf,
+			       unsigned int len, bool force_8bit)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
+		return -EINVAL;
+
+	/* Small page NANDs do not support column change. */
+	if (mtd->writesize <= 512)
+		return -ENOTSUPP;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		u8 addrs[2] = {};
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_RNDOUT, 0),
+			NAND_OP_ADDR(2, addrs, 0),
+			NAND_OP_CMD(NAND_CMD_RNDOUTSTART,
+				    PSEC_TO_NSEC(sdr->tCCS_min)),
+			NAND_OP_DATA_IN(len, buf, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+		int ret;
+
+		ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
+		if (ret < 0)
+			return ret;
+
+		/* Drop the DATA_IN instruction if len is set to 0. */
+		if (!len)
+			op.ninstrs--;
+
+		instrs[3].ctx.data.force_8bit = force_8bit;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_RNDOUT, offset_in_page, -1);
+	if (len)
+		chip->read_buf(mtd, buf, len);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_change_read_column_op);
+
+/**
+ * nand_read_oob_op - Do a READ OOB operation
+ * @chip: The NAND chip
+ * @page: page to read
+ * @offset_in_oob: offset within the OOB area
+ * @buf: buffer used to store the data
+ * @len: length of the buffer
+ *
+ * This function issues a READ OOB operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_read_oob_op(struct nand_chip *chip, unsigned int page,
+		     unsigned int offset_in_oob, void *buf, unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (offset_in_oob + len > mtd->oobsize)
+		return -EINVAL;
+
+	if (chip->exec_op)
+		return nand_read_page_op(chip, page,
+					 mtd->writesize + offset_in_oob,
+					 buf, len);
+
+	chip->cmdfunc(mtd, NAND_CMD_READOOB, offset_in_oob, page);
+	if (len)
+		chip->read_buf(mtd, buf, len);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_read_oob_op);
+
+static int nand_exec_prog_page_op(struct nand_chip *chip, unsigned int page,
+				  unsigned int offset_in_page, const void *buf,
+				  unsigned int len, bool prog)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_sdr_timings *sdr =
+		nand_get_sdr_timings(&chip->data_interface);
+	u8 addrs[5] = {};
+	struct nand_op_instr instrs[] = {
+		/*
+		 * The first instruction will be dropped if we're dealing
+		 * with a large page NAND and adjusted if we're dealing
+		 * with a small page NAND and the page offset is > 255.
+		 */
+		NAND_OP_CMD(NAND_CMD_READ0, 0),
+		NAND_OP_CMD(NAND_CMD_SEQIN, 0),
+		NAND_OP_ADDR(0, addrs, PSEC_TO_NSEC(sdr->tADL_min)),
+		NAND_OP_DATA_OUT(len, buf, 0),
+		NAND_OP_CMD(NAND_CMD_PAGEPROG, PSEC_TO_NSEC(sdr->tWB_max)),
+		NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tPROG_max), 0),
+	};
+	struct nand_operation op = NAND_OPERATION(instrs);
+	int naddrs = nand_fill_column_cycles(chip, addrs, offset_in_page);
+	int ret;
+	u8 status;
+
+	if (naddrs < 0)
+		return naddrs;
+
+	addrs[naddrs++] = page;
+	addrs[naddrs++] = page >> 8;
+	if (chip->options & NAND_ROW_ADDR_3)
+		addrs[naddrs++] = page >> 16;
+
+	instrs[2].ctx.addr.naddrs = naddrs;
+
+	/* Drop the last two instructions if we're not programming the page. */
+	if (!prog) {
+		op.ninstrs -= 2;
+		/* Also drop the DATA_OUT instruction if empty. */
+		if (!len)
+			op.ninstrs--;
+	}
+
+	if (mtd->writesize <= 512) {
+		/*
+		 * Small pages need some more tweaking: we have to adjust the
+		 * first instruction depending on the page offset we're trying
+		 * to access.
+		 */
+		if (offset_in_page >= mtd->writesize)
+			instrs[0].ctx.cmd.opcode = NAND_CMD_READOOB;
+		else if (offset_in_page >= 256 &&
+			 !(chip->options & NAND_BUSWIDTH_16))
+			instrs[0].ctx.cmd.opcode = NAND_CMD_READ1;
+	} else {
+		/*
+		 * Drop the first command if we're dealing with a large page
+		 * NAND.
+		 */
+		op.instrs++;
+		op.ninstrs--;
+	}
+
+	ret = nand_exec_op(chip, &op);
+	if (!prog || ret)
+		return ret;
+
+	ret = nand_status_op(chip, &status);
+	if (ret)
+		return ret;
+
+	return status;
+}
+
+/**
+ * nand_prog_page_begin_op - starts a PROG PAGE operation
+ * @chip: The NAND chip
+ * @page: page to write
+ * @offset_in_page: offset within the page
+ * @buf: buffer containing the data to write to the page
+ * @len: length of the buffer
+ *
+ * This function issues the first half of a PROG PAGE operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_prog_page_begin_op(struct nand_chip *chip, unsigned int page,
+			    unsigned int offset_in_page, const void *buf,
+			    unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
+		return -EINVAL;
+
+	if (chip->exec_op)
+		return nand_exec_prog_page_op(chip, page, offset_in_page, buf,
+					      len, false);
+
+	chip->cmdfunc(mtd, NAND_CMD_SEQIN, offset_in_page, page);
+
+	if (buf)
+		chip->write_buf(mtd, buf, len);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_prog_page_begin_op);
+
+/**
+ * nand_prog_page_end_op - ends a PROG PAGE operation
+ * @chip: The NAND chip
+ *
+ * This function issues the second half of a PROG PAGE operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_prog_page_end_op(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int ret;
+	u8 status;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_PAGEPROG,
+				    PSEC_TO_NSEC(sdr->tWB_max)),
+			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tPROG_max), 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		ret = nand_exec_op(chip, &op);
+		if (ret)
+			return ret;
+
+		ret = nand_status_op(chip, &status);
+		if (ret)
+			return ret;
+	} else {
+		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+		ret = chip->waitfunc(mtd, chip);
+		if (ret < 0)
+			return ret;
+
+		status = ret;
+	}
+
+	if (status & NAND_STATUS_FAIL)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_prog_page_end_op);
+
+/**
+ * nand_prog_page_op - Do a full PROG PAGE operation
+ * @chip: The NAND chip
+ * @page: page to write
+ * @offset_in_page: offset within the page
+ * @buf: buffer containing the data to write to the page
+ * @len: length of the buffer
+ *
+ * This function issues a full PROG PAGE operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_prog_page_op(struct nand_chip *chip, unsigned int page,
+		      unsigned int offset_in_page, const void *buf,
+		      unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int status;
+
+	if (!len || !buf)
+		return -EINVAL;
+
+	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
+		return -EINVAL;
+
+	if (chip->exec_op) {
+		status = nand_exec_prog_page_op(chip, page, offset_in_page, buf,
+						len, true);
+	} else {
+		chip->cmdfunc(mtd, NAND_CMD_SEQIN, offset_in_page, page);
+		chip->write_buf(mtd, buf, len);
+		chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
+		status = chip->waitfunc(mtd, chip);
+	}
+
+	if (status & NAND_STATUS_FAIL)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_prog_page_op);
+
+/**
+ * nand_change_write_column_op - Do a CHANGE WRITE COLUMN operation
+ * @chip: The NAND chip
+ * @offset_in_page: offset within the page
+ * @buf: buffer containing the data to send to the NAND
+ * @len: length of the buffer
+ * @force_8bit: force 8-bit bus access
+ *
+ * This function issues a CHANGE WRITE COLUMN operation.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_change_write_column_op(struct nand_chip *chip,
+				unsigned int offset_in_page,
+				const void *buf, unsigned int len,
+				bool force_8bit)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
+		return -EINVAL;
+
+	/* Small page NANDs do not support column change. */
+	if (mtd->writesize <= 512)
+		return -ENOTSUPP;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		u8 addrs[2];
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_RNDIN, 0),
+			NAND_OP_ADDR(2, addrs, PSEC_TO_NSEC(sdr->tCCS_min)),
+			NAND_OP_DATA_OUT(len, buf, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+		int ret;
+
+		ret = nand_fill_column_cycles(chip, addrs, offset_in_page);
+		if (ret < 0)
+			return ret;
+
+		instrs[2].ctx.data.force_8bit = force_8bit;
+
+		/* Drop the DATA_OUT instruction if len is set to 0. */
+		if (!len)
+			op.ninstrs--;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset_in_page, -1);
+	if (len)
+		chip->write_buf(mtd, buf, len);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_change_write_column_op);
+
+/**
+ * nand_readid_op - Do a READID operation
+ * @chip: The NAND chip
+ * @addr: address cycle to pass after the READID command
+ * @buf: buffer used to store the ID
+ * @len: length of the buffer
+ *
+ * This function sends a READID command and reads back the ID returned by the
+ * NAND.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_readid_op(struct nand_chip *chip, u8 addr, void *buf,
+		   unsigned int len)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int i;
+	u8 *id = buf;
+
+	if (len && !buf)
+		return -EINVAL;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_READID, 0),
+			NAND_OP_ADDR(1, &addr, PSEC_TO_NSEC(sdr->tADL_min)),
+			NAND_OP_8BIT_DATA_IN(len, buf, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		/* Drop the DATA_IN instruction if len is set to 0. */
+		if (!len)
+			op.ninstrs--;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_READID, addr, -1);
+
+	for (i = 0; i < len; i++)
+		id[i] = chip->read_byte(mtd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_readid_op);
+
+/**
+ * nand_status_op - Do a STATUS operation
+ * @chip: The NAND chip
+ * @status: out variable to store the NAND status
+ *
+ * This function sends a STATUS command and reads back the status returned by
+ * the NAND.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_status_op(struct nand_chip *chip, u8 *status)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_STATUS,
+				    PSEC_TO_NSEC(sdr->tADL_min)),
+			NAND_OP_8BIT_DATA_IN(1, status, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		if (!status)
+			op.ninstrs--;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
+	if (status)
+		*status = chip->read_byte(mtd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_status_op);
+
+/**
+ * nand_exit_status_op - Exit a STATUS operation
+ * @chip: The NAND chip
+ *
+ * This function sends a READ0 command to cancel the effect of the STATUS
+ * command to avoid reading only the status until a new read command is sent.
+ *
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_exit_status_op(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (chip->exec_op) {
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_READ0, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_READ0, -1, -1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_exit_status_op);
+
+/**
+ * nand_erase_op - Do an erase operation
+ * @chip: The NAND chip
+ * @eraseblock: block to erase
+ *
+ * This function sends an ERASE command and waits for the NAND to be ready
+ * before returning.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_erase_op(struct nand_chip *chip, unsigned int eraseblock)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int page = eraseblock <<
+			    (chip->phys_erase_shift - chip->page_shift);
+	int ret;
+	u8 status;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		u8 addrs[3] = {	page, page >> 8, page >> 16 };
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_ERASE1, 0),
+			NAND_OP_ADDR(2, addrs, 0),
+			NAND_OP_CMD(NAND_CMD_ERASE2,
+				    PSEC_TO_MSEC(sdr->tWB_max)),
+			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tBERS_max), 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		if (chip->options & NAND_ROW_ADDR_3)
+			instrs[1].ctx.addr.naddrs++;
+
+		ret = nand_exec_op(chip, &op);
+		if (ret)
+			return ret;
+
+		ret = nand_status_op(chip, &status);
+		if (ret)
+			return ret;
+	} else {
+		chip->cmdfunc(mtd, NAND_CMD_ERASE1, -1, page);
+		chip->cmdfunc(mtd, NAND_CMD_ERASE2, -1, -1);
+
+		ret = chip->waitfunc(mtd, chip);
+		if (ret < 0)
+			return ret;
+
+		status = ret;
+	}
+
+	if (status & NAND_STATUS_FAIL)
+		return -EIO;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_erase_op);
+
+/**
+ * nand_set_features_op - Do a SET FEATURES operation
+ * @chip: The NAND chip
+ * @feature: feature id
+ * @data: 4 bytes of data
+ *
+ * This function sends a SET FEATURES command and waits for the NAND to be
+ * ready before returning.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static int nand_set_features_op(struct nand_chip *chip, u8 feature,
+				const void *data)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const u8 *params = data;
+	int i, ret;
+	u8 status;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_SET_FEATURES, 0),
+			NAND_OP_ADDR(1, &feature, PSEC_TO_NSEC(sdr->tADL_min)),
+			NAND_OP_8BIT_DATA_OUT(ONFI_SUBFEATURE_PARAM_LEN, data,
+					      PSEC_TO_NSEC(sdr->tWB_max)),
+			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tFEAT_max), 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		ret = nand_exec_op(chip, &op);
+		if (ret)
+			return ret;
+
+		ret = nand_status_op(chip, &status);
+		if (ret)
+			return ret;
+	} else {
+		chip->cmdfunc(mtd, NAND_CMD_SET_FEATURES, feature, -1);
+		for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
+			chip->write_byte(mtd, params[i]);
+
+		ret = chip->waitfunc(mtd, chip);
+		if (ret < 0)
+			return ret;
+
+		status = ret;
+	}
+
+	if (status & NAND_STATUS_FAIL)
+		return -EIO;
+
+	return 0;
+}
+
+/**
+ * nand_get_features_op - Do a GET FEATURES operation
+ * @chip: The NAND chip
+ * @feature: feature id
+ * @data: 4 bytes of data
+ *
+ * This function sends a GET FEATURES command and waits for the NAND to be
+ * ready before returning.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static int nand_get_features_op(struct nand_chip *chip, u8 feature,
+				void *data)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u8 *params = data;
+	int i;
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_GET_FEATURES, 0),
+			NAND_OP_ADDR(1, &feature, PSEC_TO_NSEC(sdr->tWB_max)),
+			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tFEAT_max),
+					 PSEC_TO_NSEC(sdr->tRR_min)),
+			NAND_OP_8BIT_DATA_IN(ONFI_SUBFEATURE_PARAM_LEN,
+					     data, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_GET_FEATURES, feature, -1);
+	for (i = 0; i < ONFI_SUBFEATURE_PARAM_LEN; ++i)
+		params[i] = chip->read_byte(mtd);
+
+	return 0;
+}
+
+/**
+ * nand_reset_op - Do a reset operation
+ * @chip: The NAND chip
+ *
+ * This function sends a RESET command and waits for the NAND to be ready
+ * before returning.
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_reset_op(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (chip->exec_op) {
+		const struct nand_sdr_timings *sdr =
+			nand_get_sdr_timings(&chip->data_interface);
+		struct nand_op_instr instrs[] = {
+			NAND_OP_CMD(NAND_CMD_RESET, PSEC_TO_NSEC(sdr->tWB_max)),
+			NAND_OP_WAIT_RDY(PSEC_TO_MSEC(sdr->tRST_max), 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		return nand_exec_op(chip, &op);
+	}
+
+	chip->cmdfunc(mtd, NAND_CMD_RESET, -1, -1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_reset_op);
+
+/**
+ * nand_read_data_op - Read data from the NAND
+ * @chip: The NAND chip
+ * @buf: buffer used to store the data
+ * @len: length of the buffer
+ * @force_8bit: force 8-bit bus access
+ *
+ * This function does a raw data read on the bus. Usually used after launching
+ * another NAND operation like nand_read_page_op().
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_read_data_op(struct nand_chip *chip, void *buf, unsigned int len,
+		      bool force_8bit)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (!len || !buf)
+		return -EINVAL;
+
+	if (chip->exec_op) {
+		struct nand_op_instr instrs[] = {
+			NAND_OP_DATA_IN(len, buf, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		instrs[0].ctx.data.force_8bit = force_8bit;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	if (force_8bit) {
+		u8 *p = buf;
+		unsigned int i;
+
+		for (i = 0; i < len; i++)
+			p[i] = chip->read_byte(mtd);
+	} else {
+		chip->read_buf(mtd, buf, len);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_read_data_op);
+
+/**
+ * nand_write_data_op - Write data from the NAND
+ * @chip: The NAND chip
+ * @buf: buffer containing the data to send on the bus
+ * @len: length of the buffer
+ * @force_8bit: force 8-bit bus access
+ *
+ * This function does a raw data write on the bus. Usually used after launching
+ * another NAND operation like nand_write_page_begin_op().
+ * This function does not select/unselect the CS line.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_write_data_op(struct nand_chip *chip, const void *buf,
+		       unsigned int len, bool force_8bit)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	if (!len || !buf)
+		return -EINVAL;
+
+	if (chip->exec_op) {
+		struct nand_op_instr instrs[] = {
+			NAND_OP_DATA_OUT(len, buf, 0),
+		};
+		struct nand_operation op = NAND_OPERATION(instrs);
+
+		instrs[0].ctx.data.force_8bit = force_8bit;
+
+		return nand_exec_op(chip, &op);
+	}
+
+	if (force_8bit) {
+		const u8 *p = buf;
+		unsigned int i;
+
+		for (i = 0; i < len; i++)
+			chip->write_byte(mtd, p[i]);
+	} else {
+		chip->write_buf(mtd, buf, len);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_write_data_op);
+
+/**
+ * struct nand_op_parser_ctx - Context used by the parser
+ * @instrs: array of all the instructions that must be addressed
+ * @ninstrs: length of the @instrs array
+ * @subop: Sub-operation to be passed to the NAND controller
+ *
+ * This structure is used by the core to split NAND operations into
+ * sub-operations that can be handled by the NAND controller.
+ */
+struct nand_op_parser_ctx {
+	const struct nand_op_instr *instrs;
+	unsigned int ninstrs;
+	struct nand_subop subop;
+};
+
+/**
+ * nand_op_parser_must_split_instr - Checks if an instruction must be split
+ * @pat: the parser pattern element that matches @instr
+ * @instr: pointer to the instruction to check
+ * @start_offset: this is an in/out parameter. If @instr has already been
+ *		  split, then @start_offset is the offset from which to start
+ *		  (either an address cycle or an offset in the data buffer).
+ *		  Conversely, if the function returns true (ie. instr must be
+ *		  split), this parameter is updated to point to the first
+ *		  data/address cycle that has not been taken care of.
+ *
+ * Some NAND controllers are limited and cannot send X address cycles with a
+ * unique operation, or cannot read/write more than Y bytes at the same time.
+ * In this case, split the instruction that does not fit in a single
+ * controller-operation into two or more chunks.
+ *
+ * Returns true if the instruction must be split, false otherwise.
+ * The @start_offset parameter is also updated to the offset at which the next
+ * bundle of instruction must start (if an address or a data instruction).
+ */
+static bool
+nand_op_parser_must_split_instr(const struct nand_op_parser_pattern_elem *pat,
+				const struct nand_op_instr *instr,
+				unsigned int *start_offset)
+{
+	switch (pat->type) {
+	case NAND_OP_ADDR_INSTR:
+		if (!pat->ctx.addr.maxcycles)
+			break;
+
+		if (instr->ctx.addr.naddrs - *start_offset >
+		    pat->ctx.addr.maxcycles) {
+			*start_offset += pat->ctx.addr.maxcycles;
+			return true;
+		}
+		break;
+
+	case NAND_OP_DATA_IN_INSTR:
+	case NAND_OP_DATA_OUT_INSTR:
+		if (!pat->ctx.data.maxlen)
+			break;
+
+		if (instr->ctx.data.len - *start_offset >
+		    pat->ctx.data.maxlen) {
+			*start_offset += pat->ctx.data.maxlen;
+			return true;
+		}
+		break;
+
+	default:
+		break;
+	}
+
+	return false;
+}
+
+/**
+ * nand_op_parser_match_pat - Checks if a pattern matches the instructions
+ *			      remaining in the parser context
+ * @pat: the pattern to test
+ * @ctx: the parser context structure to match with the pattern @pat
+ *
+ * Check if @pat matches the set or a sub-set of instructions remaining in @ctx.
+ * Returns true if this is the case, false ortherwise. When true is returned,
+ * @ctx->subop is updated with the set of instructions to be passed to the
+ * controller driver.
+ */
+static bool
+nand_op_parser_match_pat(const struct nand_op_parser_pattern *pat,
+			 struct nand_op_parser_ctx *ctx)
+{
+	unsigned int instr_offset = ctx->subop.first_instr_start_off;
+	const struct nand_op_instr *end = ctx->instrs + ctx->ninstrs;
+	const struct nand_op_instr *instr = ctx->subop.instrs;
+	unsigned int i, ninstrs;
+
+	for (i = 0, ninstrs = 0; i < pat->nelems && instr < end; i++) {
+		/*
+		 * The pattern instruction does not match the operation
+		 * instruction. If the instruction is marked optional in the
+		 * pattern definition, we skip the pattern element and continue
+		 * to the next one. If the element is mandatory, there's no
+		 * match and we can return false directly.
+		 */
+		if (instr->type != pat->elems[i].type) {
+			if (!pat->elems[i].optional)
+				return false;
+
+			continue;
+		}
+
+		/*
+		 * Now check the pattern element constraints. If the pattern is
+		 * not able to handle the whole instruction in a single step,
+		 * we have to split it.
+		 * The last_instr_end_off value comes back updated to point to
+		 * the position where we have to split the instruction (the
+		 * start of the next subop chunk).
+		 */
+		if (nand_op_parser_must_split_instr(&pat->elems[i], instr,
+						    &instr_offset)) {
+			ninstrs++;
+			i++;
+			break;
+		}
+
+		instr++;
+		ninstrs++;
+		instr_offset = 0;
+	}
+
+	/*
+	 * This can happen if all instructions of a pattern are optional.
+	 * Still, if there's not at least one instruction handled by this
+	 * pattern, this is not a match, and we should try the next one (if
+	 * any).
+	 */
+	if (!ninstrs)
+		return false;
+
+	/*
+	 * We had a match on the pattern head, but the pattern may be longer
+	 * than the instructions we're asked to execute. We need to make sure
+	 * there's no mandatory elements in the pattern tail.
+	 */
+	for (; i < pat->nelems; i++) {
+		if (!pat->elems[i].optional)
+			return false;
+	}
+
+	/*
+	 * We have a match: update the subop structure accordingly and return
+	 * true.
+	 */
+	ctx->subop.ninstrs = ninstrs;
+	ctx->subop.last_instr_end_off = instr_offset;
+
+	return true;
+}
+
+#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) || defined(DEBUG)
+static void nand_op_parser_trace(const struct nand_op_parser_ctx *ctx)
+{
+	const struct nand_op_instr *instr;
+	char *prefix = "      ";
+	unsigned int i;
+
+	pr_debug("executing subop:\n");
+
+	for (i = 0; i < ctx->ninstrs; i++) {
+		instr = &ctx->instrs[i];
+
+		if (instr == &ctx->subop.instrs[0])
+			prefix = "    ->";
+
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			pr_debug("%sCMD      [0x%02x]\n", prefix,
+				 instr->ctx.cmd.opcode);
+			break;
+		case NAND_OP_ADDR_INSTR:
+			pr_debug("%sADDR     [%d cyc: %*ph]\n", prefix,
+				 instr->ctx.addr.naddrs,
+				 instr->ctx.addr.naddrs < 64 ?
+				 instr->ctx.addr.naddrs : 64,
+				 instr->ctx.addr.addrs);
+			break;
+		case NAND_OP_DATA_IN_INSTR:
+			pr_debug("%sDATA_IN  [%d B%s]\n", prefix,
+				 instr->ctx.data.len,
+				 instr->ctx.data.force_8bit ?
+				 ", force 8-bit" : "");
+			break;
+		case NAND_OP_DATA_OUT_INSTR:
+			pr_debug("%sDATA_OUT [%d B%s]\n", prefix,
+				 instr->ctx.data.len,
+				 instr->ctx.data.force_8bit ?
+				 ", force 8-bit" : "");
+			break;
+		case NAND_OP_WAITRDY_INSTR:
+			pr_debug("%sWAITRDY  [max %d ms]\n", prefix,
+				 instr->ctx.waitrdy.timeout_ms);
+			break;
+		}
+
+		if (instr == &ctx->subop.instrs[ctx->subop.ninstrs - 1])
+			prefix = "      ";
+	}
+}
+#else
+static void nand_op_parser_trace(const struct nand_op_parser_ctx *ctx)
+{
+	/* NOP */
+}
+#endif
+
+/**
+ * nand_op_parser_exec_op - exec_op parser
+ * @chip: the NAND chip
+ * @parser: patterns description provided by the controller driver
+ * @op: the NAND operation to address
+ * @check_only: when true, the function only checks if @op can be handled but
+ *		does not execute the operation
+ *
+ * Helper function designed to ease integration of NAND controller drivers that
+ * only support a limited set of instruction sequences. The supported sequences
+ * are described in @parser, and the framework takes care of splitting @op into
+ * multiple sub-operations (if required) and pass them back to the ->exec()
+ * callback of the matching pattern if @check_only is set to false.
+ *
+ * NAND controller drivers should call this function from their own ->exec_op()
+ * implementation.
+ *
+ * Returns 0 on success, a negative error code otherwise. A failure can be
+ * caused by an unsupported operation (none of the supported patterns is able
+ * to handle the requested operation), or an error returned by one of the
+ * matching pattern->exec() hook.
+ */
+int nand_op_parser_exec_op(struct nand_chip *chip,
+			   const struct nand_op_parser *parser,
+			   const struct nand_operation *op, bool check_only)
+{
+	struct nand_op_parser_ctx ctx = {
+		.subop.instrs = op->instrs,
+		.instrs = op->instrs,
+		.ninstrs = op->ninstrs,
+	};
+	unsigned int i;
+
+	while (ctx.subop.instrs < op->instrs + op->ninstrs) {
+		int ret;
+
+		for (i = 0; i < parser->npatterns; i++) {
+			const struct nand_op_parser_pattern *pattern;
+
+			pattern = &parser->patterns[i];
+			if (!nand_op_parser_match_pat(pattern, &ctx))
+				continue;
+
+			nand_op_parser_trace(&ctx);
+
+			if (check_only)
+				break;
+
+			ret = pattern->exec(chip, &ctx.subop);
+			if (ret)
+				return ret;
+
+			break;
+		}
+
+		if (i == parser->npatterns) {
+			pr_debug("->exec_op() parser: pattern not found!\n");
+			return -ENOTSUPP;
+		}
+
+		/*
+		 * Update the context structure by pointing to the start of the
+		 * next subop.
+		 */
+		ctx.subop.instrs = ctx.subop.instrs + ctx.subop.ninstrs;
+		if (ctx.subop.last_instr_end_off)
+			ctx.subop.instrs -= 1;
+
+		ctx.subop.first_instr_start_off = ctx.subop.last_instr_end_off;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_op_parser_exec_op);
+
+static bool nand_instr_is_data(const struct nand_op_instr *instr)
+{
+	return instr && (instr->type == NAND_OP_DATA_IN_INSTR ||
+			 instr->type == NAND_OP_DATA_OUT_INSTR);
+}
+
+static bool nand_subop_instr_is_valid(const struct nand_subop *subop,
+				      unsigned int instr_idx)
+{
+	return subop && instr_idx < subop->ninstrs;
+}
+
+static int nand_subop_get_start_off(const struct nand_subop *subop,
+				    unsigned int instr_idx)
+{
+	if (instr_idx)
+		return 0;
+
+	return subop->first_instr_start_off;
+}
+
+/**
+ * nand_subop_get_addr_start_off - Get the start offset in an address array
+ * @subop: The entire sub-operation
+ * @instr_idx: Index of the instruction inside the sub-operation
+ *
+ * During driver development, one could be tempted to directly use the
+ * ->addr.addrs field of address instructions. This is wrong as address
+ * instructions might be split.
+ *
+ * Given an address instruction, returns the offset of the first cycle to issue.
+ */
+int nand_subop_get_addr_start_off(const struct nand_subop *subop,
+				  unsigned int instr_idx)
+{
+	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
+	    subop->instrs[instr_idx].type != NAND_OP_ADDR_INSTR)
+		return -EINVAL;
+
+	return nand_subop_get_start_off(subop, instr_idx);
+}
+EXPORT_SYMBOL_GPL(nand_subop_get_addr_start_off);
+
+/**
+ * nand_subop_get_num_addr_cyc - Get the remaining address cycles to assert
+ * @subop: The entire sub-operation
+ * @instr_idx: Index of the instruction inside the sub-operation
+ *
+ * During driver development, one could be tempted to directly use the
+ * ->addr->naddrs field of a data instruction. This is wrong as instructions
+ * might be split.
+ *
+ * Given an address instruction, returns the number of address cycle to issue.
+ */
+int nand_subop_get_num_addr_cyc(const struct nand_subop *subop,
+				unsigned int instr_idx)
+{
+	int start_off, end_off;
+
+	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
+	    subop->instrs[instr_idx].type != NAND_OP_ADDR_INSTR)
+		return -EINVAL;
+
+	start_off = nand_subop_get_addr_start_off(subop, instr_idx);
+
+	if (instr_idx == subop->ninstrs - 1 &&
+	    subop->last_instr_end_off)
+		end_off = subop->last_instr_end_off;
+	else
+		end_off = subop->instrs[instr_idx].ctx.addr.naddrs;
+
+	return end_off - start_off;
+}
+EXPORT_SYMBOL_GPL(nand_subop_get_num_addr_cyc);
+
+/**
+ * nand_subop_get_data_start_off - Get the start offset in a data array
+ * @subop: The entire sub-operation
+ * @instr_idx: Index of the instruction inside the sub-operation
+ *
+ * During driver development, one could be tempted to directly use the
+ * ->data->buf.{in,out} field of data instructions. This is wrong as data
+ * instructions might be split.
+ *
+ * Given a data instruction, returns the offset to start from.
+ */
+int nand_subop_get_data_start_off(const struct nand_subop *subop,
+				  unsigned int instr_idx)
+{
+	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
+	    !nand_instr_is_data(&subop->instrs[instr_idx]))
+		return -EINVAL;
+
+	return nand_subop_get_start_off(subop, instr_idx);
+}
+EXPORT_SYMBOL_GPL(nand_subop_get_data_start_off);
+
+/**
+ * nand_subop_get_data_len - Get the number of bytes to retrieve
+ * @subop: The entire sub-operation
+ * @instr_idx: Index of the instruction inside the sub-operation
+ *
+ * During driver development, one could be tempted to directly use the
+ * ->data->len field of a data instruction. This is wrong as data instructions
+ * might be split.
+ *
+ * Returns the length of the chunk of data to send/receive.
+ */
+int nand_subop_get_data_len(const struct nand_subop *subop,
+			    unsigned int instr_idx)
+{
+	int start_off = 0, end_off;
+
+	if (!nand_subop_instr_is_valid(subop, instr_idx) ||
+	    !nand_instr_is_data(&subop->instrs[instr_idx]))
+		return -EINVAL;
+
+	start_off = nand_subop_get_data_start_off(subop, instr_idx);
+
+	if (instr_idx == subop->ninstrs - 1 &&
+	    subop->last_instr_end_off)
+		end_off = subop->last_instr_end_off;
+	else
+		end_off = subop->instrs[instr_idx].ctx.data.len;
+
+	return end_off - start_off;
+}
+EXPORT_SYMBOL_GPL(nand_subop_get_data_len);
+
+/**
+ * nand_reset - Reset and initialize a NAND device
+ * @chip: The NAND chip
+ * @chipnr: Internal die id
+ *
+ * Save the timings data structure, then apply SDR timings mode 0 (see
+ * nand_reset_data_interface for details), do the reset operation, and
+ * apply back the previous timings.
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+int nand_reset(struct nand_chip *chip, int chipnr)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct nand_data_interface saved_data_intf = chip->data_interface;
+	int ret;
+
+	ret = nand_reset_data_interface(chip, chipnr);
+	if (ret)
+		return ret;
+
+	/*
+	 * The CS line has to be released before we can apply the new NAND
+	 * interface settings, hence this weird ->select_chip() dance.
+	 */
+	chip->select_chip(mtd, chipnr);
+	ret = nand_reset_op(chip);
+	chip->select_chip(mtd, -1);
+	if (ret)
+		return ret;
+
+	/*
+	 * A nand_reset_data_interface() put both the NAND chip and the NAND
+	 * controller in timings mode 0. If the default mode for this chip is
+	 * also 0, no need to proceed to the change again. Plus, at probe time,
+	 * nand_setup_data_interface() uses ->set/get_features() which would
+	 * fail anyway as the parameter page is not available yet.
+	 */
+	if (!chip->onfi_timing_mode_default)
+		return 0;
+
+	chip->data_interface = saved_data_intf;
+	ret = nand_setup_data_interface(chip, chipnr);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_reset);
+
+/**
+ * nand_check_erased_buf - check if a buffer contains (almost) only 0xff data
+ * @buf: buffer to test
+ * @len: buffer length
+ * @bitflips_threshold: maximum number of bitflips
+ *
+ * Check if a buffer contains only 0xff, which means the underlying region
+ * has been erased and is ready to be programmed.
+ * The bitflips_threshold specify the maximum number of bitflips before
+ * considering the region is not erased.
+ * Note: The logic of this function has been extracted from the memweight
+ * implementation, except that nand_check_erased_buf function exit before
+ * testing the whole buffer if the number of bitflips exceed the
+ * bitflips_threshold value.
+ *
+ * Returns a positive number of bitflips less than or equal to
+ * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
+ * threshold.
+ */
+static int nand_check_erased_buf(void *buf, int len, int bitflips_threshold)
+{
+	const unsigned char *bitmap = buf;
+	int bitflips = 0;
+	int weight;
+
+	for (; len && ((uintptr_t)bitmap) % sizeof(long);
+	     len--, bitmap++) {
+		weight = hweight8(*bitmap);
+		bitflips += BITS_PER_BYTE - weight;
+		if (unlikely(bitflips > bitflips_threshold))
+			return -EBADMSG;
+	}
+
+	for (; len >= sizeof(long);
+	     len -= sizeof(long), bitmap += sizeof(long)) {
+		unsigned long d = *((unsigned long *)bitmap);
+		if (d == ~0UL)
+			continue;
+		weight = hweight_long(d);
+		bitflips += BITS_PER_LONG - weight;
+		if (unlikely(bitflips > bitflips_threshold))
+			return -EBADMSG;
+	}
+
+	for (; len > 0; len--, bitmap++) {
+		weight = hweight8(*bitmap);
+		bitflips += BITS_PER_BYTE - weight;
+		if (unlikely(bitflips > bitflips_threshold))
+			return -EBADMSG;
+	}
+
+	return bitflips;
+}
+
+/**
+ * nand_check_erased_ecc_chunk - check if an ECC chunk contains (almost) only
+ *				 0xff data
+ * @data: data buffer to test
+ * @datalen: data length
+ * @ecc: ECC buffer
+ * @ecclen: ECC length
+ * @extraoob: extra OOB buffer
+ * @extraooblen: extra OOB length
+ * @bitflips_threshold: maximum number of bitflips
+ *
+ * Check if a data buffer and its associated ECC and OOB data contains only
+ * 0xff pattern, which means the underlying region has been erased and is
+ * ready to be programmed.
+ * The bitflips_threshold specify the maximum number of bitflips before
+ * considering the region as not erased.
+ *
+ * Note:
+ * 1/ ECC algorithms are working on pre-defined block sizes which are usually
+ *    different from the NAND page size. When fixing bitflips, ECC engines will
+ *    report the number of errors per chunk, and the NAND core infrastructure
+ *    expect you to return the maximum number of bitflips for the whole page.
+ *    This is why you should always use this function on a single chunk and
+ *    not on the whole page. After checking each chunk you should update your
+ *    max_bitflips value accordingly.
+ * 2/ When checking for bitflips in erased pages you should not only check
+ *    the payload data but also their associated ECC data, because a user might
+ *    have programmed almost all bits to 1 but a few. In this case, we
+ *    shouldn't consider the chunk as erased, and checking ECC bytes prevent
+ *    this case.
+ * 3/ The extraoob argument is optional, and should be used if some of your OOB
+ *    data are protected by the ECC engine.
+ *    It could also be used if you support subpages and want to attach some
+ *    extra OOB data to an ECC chunk.
+ *
+ * Returns a positive number of bitflips less than or equal to
+ * bitflips_threshold, or -ERROR_CODE for bitflips in excess of the
+ * threshold. In case of success, the passed buffers are filled with 0xff.
+ */
+int nand_check_erased_ecc_chunk(void *data, int datalen,
+				void *ecc, int ecclen,
+				void *extraoob, int extraooblen,
+				int bitflips_threshold)
+{
+	int data_bitflips = 0, ecc_bitflips = 0, extraoob_bitflips = 0;
+
+	data_bitflips = nand_check_erased_buf(data, datalen,
+					      bitflips_threshold);
+	if (data_bitflips < 0)
+		return data_bitflips;
+
+	bitflips_threshold -= data_bitflips;
+
+	ecc_bitflips = nand_check_erased_buf(ecc, ecclen, bitflips_threshold);
+	if (ecc_bitflips < 0)
+		return ecc_bitflips;
+
+	bitflips_threshold -= ecc_bitflips;
+
+	extraoob_bitflips = nand_check_erased_buf(extraoob, extraooblen,
+						  bitflips_threshold);
+	if (extraoob_bitflips < 0)
+		return extraoob_bitflips;
+
+	if (data_bitflips)
+		memset(data, 0xff, datalen);
+
+	if (ecc_bitflips)
+		memset(ecc, 0xff, ecclen);
+
+	if (extraoob_bitflips)
+		memset(extraoob, 0xff, extraooblen);
+
+	return data_bitflips + ecc_bitflips + extraoob_bitflips;
+}
+EXPORT_SYMBOL(nand_check_erased_ecc_chunk);
+
+/**
+ * nand_read_page_raw - [INTERN] read raw page data without ecc
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Not for syndrome calculating ECC controllers, which use a special oob layout.
+ */
+int nand_read_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+		       uint8_t *buf, int oob_required, int page)
+{
+	int ret;
+
+	ret = nand_read_page_op(chip, page, 0, buf, mtd->writesize);
+	if (ret)
+		return ret;
+
+	if (oob_required) {
+		ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize,
+					false);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(nand_read_page_raw);
+
+/**
+ * nand_read_page_raw_syndrome - [INTERN] read raw page data without ecc
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * We need a special oob layout and handling even when OOB isn't used.
+ */
+static int nand_read_page_raw_syndrome(struct mtd_info *mtd,
+				       struct nand_chip *chip, uint8_t *buf,
+				       int oob_required, int page)
+{
+	int eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	uint8_t *oob = chip->oob_poi;
+	int steps, size, ret;
+
+	ret = nand_read_page_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (steps = chip->ecc.steps; steps > 0; steps--) {
+		ret = nand_read_data_op(chip, buf, eccsize, false);
+		if (ret)
+			return ret;
+
+		buf += eccsize;
+
+		if (chip->ecc.prepad) {
+			ret = nand_read_data_op(chip, oob, chip->ecc.prepad,
+						false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.prepad;
+		}
+
+		ret = nand_read_data_op(chip, oob, eccbytes, false);
+		if (ret)
+			return ret;
+
+		oob += eccbytes;
+
+		if (chip->ecc.postpad) {
+			ret = nand_read_data_op(chip, oob, chip->ecc.postpad,
+						false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.postpad;
+		}
+	}
+
+	size = mtd->oobsize - (oob - chip->oob_poi);
+	if (size) {
+		ret = nand_read_data_op(chip, oob, size, false);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * nand_read_page_swecc - [REPLACEABLE] software ECC based page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ */
+static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
+				uint8_t *buf, int oob_required, int page)
+{
+	int i, eccsize = chip->ecc.size, ret;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *p = buf;
+	uint8_t *ecc_calc = chip->ecc.calc_buf;
+	uint8_t *ecc_code = chip->ecc.code_buf;
+	unsigned int max_bitflips = 0;
+
+	chip->ecc.read_page_raw(mtd, chip, buf, 1, page);
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	eccsteps = chip->ecc.steps;
+	p = buf;
+
+	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+	return max_bitflips;
+}
+
+/**
+ * nand_read_subpage - [REPLACEABLE] ECC based sub-page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @data_offs: offset of requested data within the page
+ * @readlen: data length
+ * @bufpoi: buffer to store read data
+ * @page: page number to read
+ */
+static int nand_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
+			uint32_t data_offs, uint32_t readlen, uint8_t *bufpoi,
+			int page)
+{
+	int start_step, end_step, num_steps, ret;
+	uint8_t *p;
+	int data_col_addr, i, gaps = 0;
+	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
+	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
+	int index, section = 0;
+	unsigned int max_bitflips = 0;
+	struct mtd_oob_region oobregion = { };
+
+	/* Column address within the page aligned to ECC size (256bytes) */
+	start_step = data_offs / chip->ecc.size;
+	end_step = (data_offs + readlen - 1) / chip->ecc.size;
+	num_steps = end_step - start_step + 1;
+	index = start_step * chip->ecc.bytes;
+
+	/* Data size aligned to ECC ecc.size */
+	datafrag_len = num_steps * chip->ecc.size;
+	eccfrag_len = num_steps * chip->ecc.bytes;
+
+	data_col_addr = start_step * chip->ecc.size;
+	/* If we read not a page aligned data */
+	p = bufpoi + data_col_addr;
+	ret = nand_read_page_op(chip, page, data_col_addr, p, datafrag_len);
+	if (ret)
+		return ret;
+
+	/* Calculate ECC */
+	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size)
+		chip->ecc.calculate(mtd, p, &chip->ecc.calc_buf[i]);
+
+	/*
+	 * The performance is faster if we position offsets according to
+	 * ecc.pos. Let's make sure that there are no gaps in ECC positions.
+	 */
+	ret = mtd_ooblayout_find_eccregion(mtd, index, &section, &oobregion);
+	if (ret)
+		return ret;
+
+	if (oobregion.length < eccfrag_len)
+		gaps = 1;
+
+	if (gaps) {
+		ret = nand_change_read_column_op(chip, mtd->writesize,
+						 chip->oob_poi, mtd->oobsize,
+						 false);
+		if (ret)
+			return ret;
+	} else {
+		/*
+		 * Send the command to read the particular ECC bytes take care
+		 * about buswidth alignment in read_buf.
+		 */
+		aligned_pos = oobregion.offset & ~(busw - 1);
+		aligned_len = eccfrag_len;
+		if (oobregion.offset & (busw - 1))
+			aligned_len++;
+		if ((oobregion.offset + (num_steps * chip->ecc.bytes)) &
+		    (busw - 1))
+			aligned_len++;
+
+		ret = nand_change_read_column_op(chip,
+						 mtd->writesize + aligned_pos,
+						 &chip->oob_poi[aligned_pos],
+						 aligned_len, false);
+		if (ret)
+			return ret;
+	}
+
+	ret = mtd_ooblayout_get_eccbytes(mtd, chip->ecc.code_buf,
+					 chip->oob_poi, index, eccfrag_len);
+	if (ret)
+		return ret;
+
+	p = bufpoi + data_col_addr;
+	for (i = 0; i < eccfrag_len ; i += chip->ecc.bytes, p += chip->ecc.size) {
+		int stat;
+
+		stat = chip->ecc.correct(mtd, p, &chip->ecc.code_buf[i],
+					 &chip->ecc.calc_buf[i]);
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+						&chip->ecc.code_buf[i],
+						chip->ecc.bytes,
+						NULL, 0,
+						chip->ecc.strength);
+		}
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+	return max_bitflips;
+}
+
+/**
+ * nand_read_page_hwecc - [REPLACEABLE] hardware ECC based page read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Not for syndrome calculating ECC controllers which need a special oob layout.
+ */
+static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+				uint8_t *buf, int oob_required, int page)
+{
+	int i, eccsize = chip->ecc.size, ret;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *p = buf;
+	uint8_t *ecc_calc = chip->ecc.calc_buf;
+	uint8_t *ecc_code = chip->ecc.code_buf;
+	unsigned int max_bitflips = 0;
+
+	ret = nand_read_page_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+
+		ret = nand_read_data_op(chip, p, eccsize, false);
+		if (ret)
+			return ret;
+
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+	}
+
+	ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize, false);
+	if (ret)
+		return ret;
+
+	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	eccsteps = chip->ecc.steps;
+	p = buf;
+
+	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		stat = chip->ecc.correct(mtd, p, &ecc_code[i], &ecc_calc[i]);
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, eccsize,
+						&ecc_code[i], eccbytes,
+						NULL, 0,
+						chip->ecc.strength);
+		}
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+	return max_bitflips;
+}
+
+/**
+ * nand_read_page_hwecc_oob_first - [REPLACEABLE] hw ecc, read oob first
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * Hardware ECC for large page chips, require OOB to be read first. For this
+ * ECC mode, the write_page method is re-used from ECC_HW. These methods
+ * read/write ECC from the OOB area, unlike the ECC_HW_SYNDROME support with
+ * multiple ECC steps, follows the "infix ECC" scheme and reads/writes ECC from
+ * the data area, by overwriting the NAND manufacturer bad block markings.
+ */
+static int nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
+	struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
+{
+	int i, eccsize = chip->ecc.size, ret;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *p = buf;
+	uint8_t *ecc_code = chip->ecc.code_buf;
+	uint8_t *ecc_calc = chip->ecc.calc_buf;
+	unsigned int max_bitflips = 0;
+
+	/* Read the OOB area first */
+	ret = nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
+	if (ret)
+		return ret;
+
+	ret = nand_read_page_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	ret = mtd_ooblayout_get_eccbytes(mtd, ecc_code, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+
+		ret = nand_read_data_op(chip, p, eccsize, false);
+		if (ret)
+			return ret;
+
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+		stat = chip->ecc.correct(mtd, p, &ecc_code[i], NULL);
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, eccsize,
+						&ecc_code[i], eccbytes,
+						NULL, 0,
+						chip->ecc.strength);
+		}
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+	return max_bitflips;
+}
+
+/**
+ * nand_read_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page read
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: buffer to store read data
+ * @oob_required: caller requires OOB data read to chip->oob_poi
+ * @page: page number to read
+ *
+ * The hw generator calculates the error syndrome automatically. Therefore we
+ * need a special oob layout and handling.
+ */
+static int nand_read_page_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+				   uint8_t *buf, int oob_required, int page)
+{
+	int ret, i, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	int eccpadbytes = eccbytes + chip->ecc.prepad + chip->ecc.postpad;
+	uint8_t *p = buf;
+	uint8_t *oob = chip->oob_poi;
+	unsigned int max_bitflips = 0;
+
+	ret = nand_read_page_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		int stat;
+
+		chip->ecc.hwctl(mtd, NAND_ECC_READ);
+
+		ret = nand_read_data_op(chip, p, eccsize, false);
+		if (ret)
+			return ret;
+
+		if (chip->ecc.prepad) {
+			ret = nand_read_data_op(chip, oob, chip->ecc.prepad,
+						false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.prepad;
+		}
+
+		chip->ecc.hwctl(mtd, NAND_ECC_READSYN);
+
+		ret = nand_read_data_op(chip, oob, eccbytes, false);
+		if (ret)
+			return ret;
+
+		stat = chip->ecc.correct(mtd, p, oob, NULL);
+
+		oob += eccbytes;
+
+		if (chip->ecc.postpad) {
+			ret = nand_read_data_op(chip, oob, chip->ecc.postpad,
+						false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.postpad;
+		}
+
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+							   oob - eccpadbytes,
+							   eccpadbytes,
+							   NULL, 0,
+							   chip->ecc.strength);
+		}
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+
+	/* Calculate remaining oob bytes */
+	i = mtd->oobsize - (oob - chip->oob_poi);
+	if (i) {
+		ret = nand_read_data_op(chip, oob, i, false);
+		if (ret)
+			return ret;
+	}
+
+	return max_bitflips;
+}
+
+/**
+ * nand_transfer_oob - [INTERN] Transfer oob to client buffer
+ * @mtd: mtd info structure
+ * @oob: oob destination address
+ * @ops: oob ops structure
+ * @len: size of oob to transfer
+ */
+static uint8_t *nand_transfer_oob(struct mtd_info *mtd, uint8_t *oob,
+				  struct mtd_oob_ops *ops, size_t len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret;
+
+	switch (ops->mode) {
+
+	case MTD_OPS_PLACE_OOB:
+	case MTD_OPS_RAW:
+		memcpy(oob, chip->oob_poi + ops->ooboffs, len);
+		return oob + len;
+
+	case MTD_OPS_AUTO_OOB:
+		ret = mtd_ooblayout_get_databytes(mtd, oob, chip->oob_poi,
+						  ops->ooboffs, len);
+		BUG_ON(ret);
+		return oob + len;
+
+	default:
+		BUG();
+	}
+	return NULL;
+}
+
+/**
+ * nand_setup_read_retry - [INTERN] Set the READ RETRY mode
+ * @mtd: MTD device structure
+ * @retry_mode: the retry mode to use
+ *
+ * Some vendors supply a special command to shift the Vt threshold, to be used
+ * when there are too many bitflips in a page (i.e., ECC error). After setting
+ * a new threshold, the host should retry reading the page.
+ */
+static int nand_setup_read_retry(struct mtd_info *mtd, int retry_mode)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	pr_debug("setting READ RETRY mode %d\n", retry_mode);
+
+	if (retry_mode >= chip->read_retries)
+		return -EINVAL;
+
+	if (!chip->setup_read_retry)
+		return -EOPNOTSUPP;
+
+	return chip->setup_read_retry(mtd, retry_mode);
+}
+
+/**
+ * nand_do_read_ops - [INTERN] Read data with ECC
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @ops: oob ops structure
+ *
+ * Internal function. Called with chip held.
+ */
+static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
+			    struct mtd_oob_ops *ops)
+{
+	int chipnr, page, realpage, col, bytes, aligned, oob_required;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret = 0;
+	uint32_t readlen = ops->len;
+	uint32_t oobreadlen = ops->ooblen;
+	uint32_t max_oobsize = mtd_oobavail(mtd, ops);
+
+	uint8_t *bufpoi, *oob, *buf;
+	int use_bufpoi;
+	unsigned int max_bitflips = 0;
+	int retry_mode = 0;
+	bool ecc_fail = false;
+
+	chipnr = (int)(from >> chip->chip_shift);
+	chip->select_chip(mtd, chipnr);
+
+	realpage = (int)(from >> chip->page_shift);
+	page = realpage & chip->pagemask;
+
+	col = (int)(from & (mtd->writesize - 1));
+
+	buf = ops->datbuf;
+	oob = ops->oobbuf;
+	oob_required = oob ? 1 : 0;
+
+	while (1) {
+		unsigned int ecc_failures = mtd->ecc_stats.failed;
+
+		bytes = min(mtd->writesize - col, readlen);
+		aligned = (bytes == mtd->writesize);
+
+		if (!aligned)
+			use_bufpoi = 1;
+		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
+			use_bufpoi = !virt_addr_valid(buf) ||
+				     !IS_ALIGNED((unsigned long)buf,
+						 chip->buf_align);
+		else
+			use_bufpoi = 0;
+
+		/* Is the current page in the buffer? */
+		if (realpage != chip->pagebuf || oob) {
+			bufpoi = use_bufpoi ? chip->data_buf : buf;
+
+			if (use_bufpoi && aligned)
+				pr_debug("%s: using read bounce buffer for buf@%p\n",
+						 __func__, buf);
+
+read_retry:
+			/*
+			 * Now read the page into the buffer.  Absent an error,
+			 * the read methods return max bitflips per ecc step.
+			 */
+			if (unlikely(ops->mode == MTD_OPS_RAW))
+				ret = chip->ecc.read_page_raw(mtd, chip, bufpoi,
+							      oob_required,
+							      page);
+			else if (!aligned && NAND_HAS_SUBPAGE_READ(chip) &&
+				 !oob)
+				ret = chip->ecc.read_subpage(mtd, chip,
+							col, bytes, bufpoi,
+							page);
+			else
+				ret = chip->ecc.read_page(mtd, chip, bufpoi,
+							  oob_required, page);
+			if (ret < 0) {
+				if (use_bufpoi)
+					/* Invalidate page cache */
+					chip->pagebuf = -1;
+				break;
+			}
+
+			/* Transfer not aligned data */
+			if (use_bufpoi) {
+				if (!NAND_HAS_SUBPAGE_READ(chip) && !oob &&
+				    !(mtd->ecc_stats.failed - ecc_failures) &&
+				    (ops->mode != MTD_OPS_RAW)) {
+					chip->pagebuf = realpage;
+					chip->pagebuf_bitflips = ret;
+				} else {
+					/* Invalidate page cache */
+					chip->pagebuf = -1;
+				}
+				memcpy(buf, chip->data_buf + col, bytes);
+			}
+
+			if (unlikely(oob)) {
+				int toread = min(oobreadlen, max_oobsize);
+
+				if (toread) {
+					oob = nand_transfer_oob(mtd,
+						oob, ops, toread);
+					oobreadlen -= toread;
+				}
+			}
+
+			if (chip->options & NAND_NEED_READRDY) {
+				/* Apply delay or wait for ready/busy pin */
+				if (!chip->dev_ready)
+					udelay(chip->chip_delay);
+				else
+					nand_wait_ready(mtd);
+			}
+
+			if (mtd->ecc_stats.failed - ecc_failures) {
+				if (retry_mode + 1 < chip->read_retries) {
+					retry_mode++;
+					ret = nand_setup_read_retry(mtd,
+							retry_mode);
+					if (ret < 0)
+						break;
+
+					/* Reset failures; retry */
+					mtd->ecc_stats.failed = ecc_failures;
+					goto read_retry;
+				} else {
+					/* No more retry modes; real failure */
+					ecc_fail = true;
+				}
+			}
+
+			buf += bytes;
+			max_bitflips = max_t(unsigned int, max_bitflips, ret);
+		} else {
+			memcpy(buf, chip->data_buf + col, bytes);
+			buf += bytes;
+			max_bitflips = max_t(unsigned int, max_bitflips,
+					     chip->pagebuf_bitflips);
+		}
+
+		readlen -= bytes;
+
+		/* Reset to retry mode 0 */
+		if (retry_mode) {
+			ret = nand_setup_read_retry(mtd, 0);
+			if (ret < 0)
+				break;
+			retry_mode = 0;
+		}
+
+		if (!readlen)
+			break;
+
+		/* For subsequent reads align to page boundary */
+		col = 0;
+		/* Increment page address */
+		realpage++;
+
+		page = realpage & chip->pagemask;
+		/* Check, if we cross a chip boundary */
+		if (!page) {
+			chipnr++;
+			chip->select_chip(mtd, -1);
+			chip->select_chip(mtd, chipnr);
+		}
+	}
+	chip->select_chip(mtd, -1);
+
+	ops->retlen = ops->len - (size_t) readlen;
+	if (oob)
+		ops->oobretlen = ops->ooblen - oobreadlen;
+
+	if (ret < 0)
+		return ret;
+
+	if (ecc_fail)
+		return -EBADMSG;
+
+	return max_bitflips;
+}
+
+/**
+ * nand_read_oob_std - [REPLACEABLE] the most common OOB data read function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to read
+ */
+int nand_read_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page)
+{
+	return nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
+}
+EXPORT_SYMBOL(nand_read_oob_std);
+
+/**
+ * nand_read_oob_syndrome - [REPLACEABLE] OOB data read function for HW ECC
+ *			    with syndromes
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to read
+ */
+int nand_read_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+			   int page)
+{
+	int length = mtd->oobsize;
+	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
+	int eccsize = chip->ecc.size;
+	uint8_t *bufpoi = chip->oob_poi;
+	int i, toread, sndrnd = 0, pos, ret;
+
+	ret = nand_read_page_op(chip, page, chip->ecc.size, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < chip->ecc.steps; i++) {
+		if (sndrnd) {
+			int ret;
+
+			pos = eccsize + i * (eccsize + chunk);
+			if (mtd->writesize > 512)
+				ret = nand_change_read_column_op(chip, pos,
+								 NULL, 0,
+								 false);
+			else
+				ret = nand_read_page_op(chip, page, pos, NULL,
+							0);
+
+			if (ret)
+				return ret;
+		} else
+			sndrnd = 1;
+		toread = min_t(int, length, chunk);
+
+		ret = nand_read_data_op(chip, bufpoi, toread, false);
+		if (ret)
+			return ret;
+
+		bufpoi += toread;
+		length -= toread;
+	}
+	if (length > 0) {
+		ret = nand_read_data_op(chip, bufpoi, length, false);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(nand_read_oob_syndrome);
+
+/**
+ * nand_write_oob_std - [REPLACEABLE] the most common OOB data write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to write
+ */
+int nand_write_oob_std(struct mtd_info *mtd, struct nand_chip *chip, int page)
+{
+	return nand_prog_page_op(chip, page, mtd->writesize, chip->oob_poi,
+				 mtd->oobsize);
+}
+EXPORT_SYMBOL(nand_write_oob_std);
+
+/**
+ * nand_write_oob_syndrome - [REPLACEABLE] OOB data write function for HW ECC
+ *			     with syndrome - only for large page flash
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @page: page number to write
+ */
+int nand_write_oob_syndrome(struct mtd_info *mtd, struct nand_chip *chip,
+			    int page)
+{
+	int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
+	int eccsize = chip->ecc.size, length = mtd->oobsize;
+	int ret, i, len, pos, sndcmd = 0, steps = chip->ecc.steps;
+	const uint8_t *bufpoi = chip->oob_poi;
+
+	/*
+	 * data-ecc-data-ecc ... ecc-oob
+	 * or
+	 * data-pad-ecc-pad-data-pad .... ecc-pad-oob
+	 */
+	if (!chip->ecc.prepad && !chip->ecc.postpad) {
+		pos = steps * (eccsize + chunk);
+		steps = 0;
+	} else
+		pos = eccsize;
+
+	ret = nand_prog_page_begin_op(chip, page, pos, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < steps; i++) {
+		if (sndcmd) {
+			if (mtd->writesize <= 512) {
+				uint32_t fill = 0xFFFFFFFF;
+
+				len = eccsize;
+				while (len > 0) {
+					int num = min_t(int, len, 4);
+
+					ret = nand_write_data_op(chip, &fill,
+								 num, false);
+					if (ret)
+						return ret;
+
+					len -= num;
+				}
+			} else {
+				pos = eccsize + i * (eccsize + chunk);
+				ret = nand_change_write_column_op(chip, pos,
+								  NULL, 0,
+								  false);
+				if (ret)
+					return ret;
+			}
+		} else
+			sndcmd = 1;
+		len = min_t(int, length, chunk);
+
+		ret = nand_write_data_op(chip, bufpoi, len, false);
+		if (ret)
+			return ret;
+
+		bufpoi += len;
+		length -= len;
+	}
+	if (length > 0) {
+		ret = nand_write_data_op(chip, bufpoi, length, false);
+		if (ret)
+			return ret;
+	}
+
+	return nand_prog_page_end_op(chip);
+}
+EXPORT_SYMBOL(nand_write_oob_syndrome);
+
+/**
+ * nand_do_read_oob - [INTERN] NAND read out-of-band
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @ops: oob operations description structure
+ *
+ * NAND read out-of-band data from the spare area.
+ */
+static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
+			    struct mtd_oob_ops *ops)
+{
+	unsigned int max_bitflips = 0;
+	int page, realpage, chipnr;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtd_ecc_stats stats;
+	int readlen = ops->ooblen;
+	int len;
+	uint8_t *buf = ops->oobbuf;
+	int ret = 0;
+
+	pr_debug("%s: from = 0x%08Lx, len = %i\n",
+			__func__, (unsigned long long)from, readlen);
+
+	stats = mtd->ecc_stats;
+
+	len = mtd_oobavail(mtd, ops);
+
+	chipnr = (int)(from >> chip->chip_shift);
+	chip->select_chip(mtd, chipnr);
+
+	/* Shift to get page */
+	realpage = (int)(from >> chip->page_shift);
+	page = realpage & chip->pagemask;
+
+	while (1) {
+		if (ops->mode == MTD_OPS_RAW)
+			ret = chip->ecc.read_oob_raw(mtd, chip, page);
+		else
+			ret = chip->ecc.read_oob(mtd, chip, page);
+
+		if (ret < 0)
+			break;
+
+		len = min(len, readlen);
+		buf = nand_transfer_oob(mtd, buf, ops, len);
+
+		if (chip->options & NAND_NEED_READRDY) {
+			/* Apply delay or wait for ready/busy pin */
+			if (!chip->dev_ready)
+				udelay(chip->chip_delay);
+			else
+				nand_wait_ready(mtd);
+		}
+
+		max_bitflips = max_t(unsigned int, max_bitflips, ret);
+
+		readlen -= len;
+		if (!readlen)
+			break;
+
+		/* Increment page address */
+		realpage++;
+
+		page = realpage & chip->pagemask;
+		/* Check, if we cross a chip boundary */
+		if (!page) {
+			chipnr++;
+			chip->select_chip(mtd, -1);
+			chip->select_chip(mtd, chipnr);
+		}
+	}
+	chip->select_chip(mtd, -1);
+
+	ops->oobretlen = ops->ooblen - readlen;
+
+	if (ret < 0)
+		return ret;
+
+	if (mtd->ecc_stats.failed - stats.failed)
+		return -EBADMSG;
+
+	return max_bitflips;
+}
+
+/**
+ * nand_read_oob - [MTD Interface] NAND read data and/or out-of-band
+ * @mtd: MTD device structure
+ * @from: offset to read from
+ * @ops: oob operation description structure
+ *
+ * NAND read data and/or out-of-band data.
+ */
+static int nand_read_oob(struct mtd_info *mtd, loff_t from,
+			 struct mtd_oob_ops *ops)
+{
+	int ret;
+
+	ops->retlen = 0;
+
+	if (ops->mode != MTD_OPS_PLACE_OOB &&
+	    ops->mode != MTD_OPS_AUTO_OOB &&
+	    ops->mode != MTD_OPS_RAW)
+		return -ENOTSUPP;
+
+	nand_get_device(mtd, FL_READING);
+
+	if (!ops->datbuf)
+		ret = nand_do_read_oob(mtd, from, ops);
+	else
+		ret = nand_do_read_ops(mtd, from, ops);
+
+	nand_release_device(mtd);
+	return ret;
+}
+
+
+/**
+ * nand_write_page_raw - [INTERN] raw page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ *
+ * Not for syndrome calculating ECC controllers, which use a special oob layout.
+ */
+int nand_write_page_raw(struct mtd_info *mtd, struct nand_chip *chip,
+			const uint8_t *buf, int oob_required, int page)
+{
+	int ret;
+
+	ret = nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
+	if (ret)
+		return ret;
+
+	if (oob_required) {
+		ret = nand_write_data_op(chip, chip->oob_poi, mtd->oobsize,
+					 false);
+		if (ret)
+			return ret;
+	}
+
+	return nand_prog_page_end_op(chip);
+}
+EXPORT_SYMBOL(nand_write_page_raw);
+
+/**
+ * nand_write_page_raw_syndrome - [INTERN] raw page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ *
+ * We need a special oob layout and handling even when ECC isn't checked.
+ */
+static int nand_write_page_raw_syndrome(struct mtd_info *mtd,
+					struct nand_chip *chip,
+					const uint8_t *buf, int oob_required,
+					int page)
+{
+	int eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	uint8_t *oob = chip->oob_poi;
+	int steps, size, ret;
+
+	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (steps = chip->ecc.steps; steps > 0; steps--) {
+		ret = nand_write_data_op(chip, buf, eccsize, false);
+		if (ret)
+			return ret;
+
+		buf += eccsize;
+
+		if (chip->ecc.prepad) {
+			ret = nand_write_data_op(chip, oob, chip->ecc.prepad,
+						 false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.prepad;
+		}
+
+		ret = nand_write_data_op(chip, oob, eccbytes, false);
+		if (ret)
+			return ret;
+
+		oob += eccbytes;
+
+		if (chip->ecc.postpad) {
+			ret = nand_write_data_op(chip, oob, chip->ecc.postpad,
+						 false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.postpad;
+		}
+	}
+
+	size = mtd->oobsize - (oob - chip->oob_poi);
+	if (size) {
+		ret = nand_write_data_op(chip, oob, size, false);
+		if (ret)
+			return ret;
+	}
+
+	return nand_prog_page_end_op(chip);
+}
+/**
+ * nand_write_page_swecc - [REPLACEABLE] software ECC based page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ */
+static int nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
+				 const uint8_t *buf, int oob_required,
+				 int page)
+{
+	int i, eccsize = chip->ecc.size, ret;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *ecc_calc = chip->ecc.calc_buf;
+	const uint8_t *p = buf;
+
+	/* Software ECC calculation */
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize)
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+
+	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	return chip->ecc.write_page_raw(mtd, chip, buf, 1, page);
+}
+
+/**
+ * nand_write_page_hwecc - [REPLACEABLE] hardware ECC based page write function
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ */
+static int nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
+				  const uint8_t *buf, int oob_required,
+				  int page)
+{
+	int i, eccsize = chip->ecc.size, ret;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	uint8_t *ecc_calc = chip->ecc.calc_buf;
+	const uint8_t *p = buf;
+
+	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+
+		ret = nand_write_data_op(chip, p, eccsize, false);
+		if (ret)
+			return ret;
+
+		chip->ecc.calculate(mtd, p, &ecc_calc[i]);
+	}
+
+	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	ret = nand_write_data_op(chip, chip->oob_poi, mtd->oobsize, false);
+	if (ret)
+		return ret;
+
+	return nand_prog_page_end_op(chip);
+}
+
+
+/**
+ * nand_write_subpage_hwecc - [REPLACEABLE] hardware ECC based subpage write
+ * @mtd:	mtd info structure
+ * @chip:	nand chip info structure
+ * @offset:	column address of subpage within the page
+ * @data_len:	data length
+ * @buf:	data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ */
+static int nand_write_subpage_hwecc(struct mtd_info *mtd,
+				struct nand_chip *chip, uint32_t offset,
+				uint32_t data_len, const uint8_t *buf,
+				int oob_required, int page)
+{
+	uint8_t *oob_buf  = chip->oob_poi;
+	uint8_t *ecc_calc = chip->ecc.calc_buf;
+	int ecc_size      = chip->ecc.size;
+	int ecc_bytes     = chip->ecc.bytes;
+	int ecc_steps     = chip->ecc.steps;
+	uint32_t start_step = offset / ecc_size;
+	uint32_t end_step   = (offset + data_len - 1) / ecc_size;
+	int oob_bytes       = mtd->oobsize / ecc_steps;
+	int step, ret;
+
+	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (step = 0; step < ecc_steps; step++) {
+		/* configure controller for WRITE access */
+		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+
+		/* write data (untouched subpages already masked by 0xFF) */
+		ret = nand_write_data_op(chip, buf, ecc_size, false);
+		if (ret)
+			return ret;
+
+		/* mask ECC of un-touched subpages by padding 0xFF */
+		if ((step < start_step) || (step > end_step))
+			memset(ecc_calc, 0xff, ecc_bytes);
+		else
+			chip->ecc.calculate(mtd, buf, ecc_calc);
+
+		/* mask OOB of un-touched subpages by padding 0xFF */
+		/* if oob_required, preserve OOB metadata of written subpage */
+		if (!oob_required || (step < start_step) || (step > end_step))
+			memset(oob_buf, 0xff, oob_bytes);
+
+		buf += ecc_size;
+		ecc_calc += ecc_bytes;
+		oob_buf  += oob_bytes;
+	}
+
+	/* copy calculated ECC for whole page to chip->buffer->oob */
+	/* this include masked-value(0xFF) for unwritten subpages */
+	ecc_calc = chip->ecc.calc_buf;
+	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	/* write OOB buffer to NAND device */
+	ret = nand_write_data_op(chip, chip->oob_poi, mtd->oobsize, false);
+	if (ret)
+		return ret;
+
+	return nand_prog_page_end_op(chip);
+}
+
+
+/**
+ * nand_write_page_syndrome - [REPLACEABLE] hardware ECC syndrome based page write
+ * @mtd: mtd info structure
+ * @chip: nand chip info structure
+ * @buf: data buffer
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ *
+ * The hw generator calculates the error syndrome automatically. Therefore we
+ * need a special oob layout and handling.
+ */
+static int nand_write_page_syndrome(struct mtd_info *mtd,
+				    struct nand_chip *chip,
+				    const uint8_t *buf, int oob_required,
+				    int page)
+{
+	int i, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	const uint8_t *p = buf;
+	uint8_t *oob = chip->oob_poi;
+	int ret;
+
+	ret = nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+	if (ret)
+		return ret;
+
+	for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+
+		ret = nand_write_data_op(chip, p, eccsize, false);
+		if (ret)
+			return ret;
+
+		if (chip->ecc.prepad) {
+			ret = nand_write_data_op(chip, oob, chip->ecc.prepad,
+						 false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.prepad;
+		}
+
+		chip->ecc.calculate(mtd, p, oob);
+
+		ret = nand_write_data_op(chip, oob, eccbytes, false);
+		if (ret)
+			return ret;
+
+		oob += eccbytes;
+
+		if (chip->ecc.postpad) {
+			ret = nand_write_data_op(chip, oob, chip->ecc.postpad,
+						 false);
+			if (ret)
+				return ret;
+
+			oob += chip->ecc.postpad;
+		}
+	}
+
+	/* Calculate remaining oob bytes */
+	i = mtd->oobsize - (oob - chip->oob_poi);
+	if (i) {
+		ret = nand_write_data_op(chip, oob, i, false);
+		if (ret)
+			return ret;
+	}
+
+	return nand_prog_page_end_op(chip);
+}
+
+/**
+ * nand_write_page - write one page
+ * @mtd: MTD device structure
+ * @chip: NAND chip descriptor
+ * @offset: address offset within the page
+ * @data_len: length of actual data to be written
+ * @buf: the data to write
+ * @oob_required: must write chip->oob_poi to OOB
+ * @page: page number to write
+ * @raw: use _raw version of write_page
+ */
+static int nand_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+		uint32_t offset, int data_len, const uint8_t *buf,
+		int oob_required, int page, int raw)
+{
+	int status, subpage;
+
+	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&
+		chip->ecc.write_subpage)
+		subpage = offset || (data_len < mtd->writesize);
+	else
+		subpage = 0;
+
+	if (unlikely(raw))
+		status = chip->ecc.write_page_raw(mtd, chip, buf,
+						  oob_required, page);
+	else if (subpage)
+		status = chip->ecc.write_subpage(mtd, chip, offset, data_len,
+						 buf, oob_required, page);
+	else
+		status = chip->ecc.write_page(mtd, chip, buf, oob_required,
+					      page);
+
+	if (status < 0)
+		return status;
+
+	return 0;
+}
+
+/**
+ * nand_fill_oob - [INTERN] Transfer client buffer to oob
+ * @mtd: MTD device structure
+ * @oob: oob data buffer
+ * @len: oob data write length
+ * @ops: oob ops structure
+ */
+static uint8_t *nand_fill_oob(struct mtd_info *mtd, uint8_t *oob, size_t len,
+			      struct mtd_oob_ops *ops)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret;
+
+	/*
+	 * Initialise to all 0xFF, to avoid the possibility of left over OOB
+	 * data from a previous OOB read.
+	 */
+	memset(chip->oob_poi, 0xff, mtd->oobsize);
+
+	switch (ops->mode) {
+
+	case MTD_OPS_PLACE_OOB:
+	case MTD_OPS_RAW:
+		memcpy(chip->oob_poi + ops->ooboffs, oob, len);
+		return oob + len;
+
+	case MTD_OPS_AUTO_OOB:
+		ret = mtd_ooblayout_set_databytes(mtd, oob, chip->oob_poi,
+						  ops->ooboffs, len);
+		BUG_ON(ret);
+		return oob + len;
+
+	default:
+		BUG();
+	}
+	return NULL;
+}
+
+#define NOTALIGNED(x)	((x & (chip->subpagesize - 1)) != 0)
+
+/**
+ * nand_do_write_ops - [INTERN] NAND write with ECC
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @ops: oob operations description structure
+ *
+ * NAND write with ECC.
+ */
+static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
+			     struct mtd_oob_ops *ops)
+{
+	int chipnr, realpage, page, column;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	uint32_t writelen = ops->len;
+
+	uint32_t oobwritelen = ops->ooblen;
+	uint32_t oobmaxlen = mtd_oobavail(mtd, ops);
+
+	uint8_t *oob = ops->oobbuf;
+	uint8_t *buf = ops->datbuf;
+	int ret;
+	int oob_required = oob ? 1 : 0;
+
+	ops->retlen = 0;
+	if (!writelen)
+		return 0;
+
+	/* Reject writes, which are not page aligned */
+	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
+		pr_notice("%s: attempt to write non page aligned data\n",
+			   __func__);
+		return -EINVAL;
+	}
+
+	column = to & (mtd->writesize - 1);
+
+	chipnr = (int)(to >> chip->chip_shift);
+	chip->select_chip(mtd, chipnr);
+
+	/* Check, if it is write protected */
+	if (nand_check_wp(mtd)) {
+		ret = -EIO;
+		goto err_out;
+	}
+
+	realpage = (int)(to >> chip->page_shift);
+	page = realpage & chip->pagemask;
+
+	/* Invalidate the page cache, when we write to the cached page */
+	if (to <= ((loff_t)chip->pagebuf << chip->page_shift) &&
+	    ((loff_t)chip->pagebuf << chip->page_shift) < (to + ops->len))
+		chip->pagebuf = -1;
+
+	/* Don't allow multipage oob writes with offset */
+	if (oob && ops->ooboffs && (ops->ooboffs + ops->ooblen > oobmaxlen)) {
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	while (1) {
+		int bytes = mtd->writesize;
+		uint8_t *wbuf = buf;
+		int use_bufpoi;
+		int part_pagewr = (column || writelen < mtd->writesize);
+
+		if (part_pagewr)
+			use_bufpoi = 1;
+		else if (chip->options & NAND_USE_BOUNCE_BUFFER)
+			use_bufpoi = !virt_addr_valid(buf) ||
+				     !IS_ALIGNED((unsigned long)buf,
+						 chip->buf_align);
+		else
+			use_bufpoi = 0;
+
+		/* Partial page write?, or need to use bounce buffer */
+		if (use_bufpoi) {
+			pr_debug("%s: using write bounce buffer for buf@%p\n",
+					 __func__, buf);
+			if (part_pagewr)
+				bytes = min_t(int, bytes - column, writelen);
+			chip->pagebuf = -1;
+			memset(chip->data_buf, 0xff, mtd->writesize);
+			memcpy(&chip->data_buf[column], buf, bytes);
+			wbuf = chip->data_buf;
+		}
+
+		if (unlikely(oob)) {
+			size_t len = min(oobwritelen, oobmaxlen);
+			oob = nand_fill_oob(mtd, oob, len, ops);
+			oobwritelen -= len;
+		} else {
+			/* We still need to erase leftover OOB data */
+			memset(chip->oob_poi, 0xff, mtd->oobsize);
+		}
+
+		ret = nand_write_page(mtd, chip, column, bytes, wbuf,
+				      oob_required, page,
+				      (ops->mode == MTD_OPS_RAW));
+		if (ret)
+			break;
+
+		writelen -= bytes;
+		if (!writelen)
+			break;
+
+		column = 0;
+		buf += bytes;
+		realpage++;
+
+		page = realpage & chip->pagemask;
+		/* Check, if we cross a chip boundary */
+		if (!page) {
+			chipnr++;
+			chip->select_chip(mtd, -1);
+			chip->select_chip(mtd, chipnr);
+		}
+	}
+
+	ops->retlen = ops->len - writelen;
+	if (unlikely(oob))
+		ops->oobretlen = ops->ooblen;
+
+err_out:
+	chip->select_chip(mtd, -1);
+	return ret;
+}
+
+/**
+ * panic_nand_write - [MTD Interface] NAND write with ECC
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @len: number of bytes to write
+ * @retlen: pointer to variable to store the number of written bytes
+ * @buf: the data to write
+ *
+ * NAND write with ECC. Used when performing writes in interrupt context, this
+ * may for example be called by mtdoops when writing an oops while in panic.
+ */
+static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
+			    size_t *retlen, const uint8_t *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int chipnr = (int)(to >> chip->chip_shift);
+	struct mtd_oob_ops ops;
+	int ret;
+
+	/* Grab the device */
+	panic_nand_get_device(chip, mtd, FL_WRITING);
+
+	chip->select_chip(mtd, chipnr);
+
+	/* Wait for the device to get ready */
+	panic_nand_wait(mtd, chip, 400);
+
+	memset(&ops, 0, sizeof(ops));
+	ops.len = len;
+	ops.datbuf = (uint8_t *)buf;
+	ops.mode = MTD_OPS_PLACE_OOB;
+
+	ret = nand_do_write_ops(mtd, to, &ops);
+
+	*retlen = ops.retlen;
+	return ret;
+}
+
+/**
+ * nand_do_write_oob - [MTD Interface] NAND write out-of-band
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @ops: oob operation description structure
+ *
+ * NAND write out-of-band.
+ */
+static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
+			     struct mtd_oob_ops *ops)
+{
+	int chipnr, page, status, len;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	pr_debug("%s: to = 0x%08x, len = %i\n",
+			 __func__, (unsigned int)to, (int)ops->ooblen);
+
+	len = mtd_oobavail(mtd, ops);
+
+	/* Do not allow write past end of page */
+	if ((ops->ooboffs + ops->ooblen) > len) {
+		pr_debug("%s: attempt to write past end of page\n",
+				__func__);
+		return -EINVAL;
+	}
+
+	chipnr = (int)(to >> chip->chip_shift);
+
+	/*
+	 * Reset the chip. Some chips (like the Toshiba TC5832DC found in one
+	 * of my DiskOnChip 2000 test units) will clear the whole data page too
+	 * if we don't do this. I have no clue why, but I seem to have 'fixed'
+	 * it in the doc2000 driver in August 1999.  dwmw2.
+	 */
+	nand_reset(chip, chipnr);
+
+	chip->select_chip(mtd, chipnr);
+
+	/* Shift to get page */
+	page = (int)(to >> chip->page_shift);
+
+	/* Check, if it is write protected */
+	if (nand_check_wp(mtd)) {
+		chip->select_chip(mtd, -1);
+		return -EROFS;
+	}
+
+	/* Invalidate the page cache, if we write to the cached page */
+	if (page == chip->pagebuf)
+		chip->pagebuf = -1;
+
+	nand_fill_oob(mtd, ops->oobbuf, ops->ooblen, ops);
+
+	if (ops->mode == MTD_OPS_RAW)
+		status = chip->ecc.write_oob_raw(mtd, chip, page & chip->pagemask);
+	else
+		status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
+
+	chip->select_chip(mtd, -1);
+
+	if (status)
+		return status;
+
+	ops->oobretlen = ops->ooblen;
+
+	return 0;
+}
+
+/**
+ * nand_write_oob - [MTD Interface] NAND write data and/or out-of-band
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @ops: oob operation description structure
+ */
+static int nand_write_oob(struct mtd_info *mtd, loff_t to,
+			  struct mtd_oob_ops *ops)
+{
+	int ret = -ENOTSUPP;
+
+	ops->retlen = 0;
+
+	nand_get_device(mtd, FL_WRITING);
+
+	switch (ops->mode) {
+	case MTD_OPS_PLACE_OOB:
+	case MTD_OPS_AUTO_OOB:
+	case MTD_OPS_RAW:
+		break;
+
+	default:
+		goto out;
+	}
+
+	if (!ops->datbuf)
+		ret = nand_do_write_oob(mtd, to, ops);
+	else
+		ret = nand_do_write_ops(mtd, to, ops);
+
+out:
+	nand_release_device(mtd);
+	return ret;
+}
+
+/**
+ * single_erase - [GENERIC] NAND standard block erase command function
+ * @mtd: MTD device structure
+ * @page: the page address of the block which will be erased
+ *
+ * Standard erase command for NAND chips. Returns NAND status.
+ */
+static int single_erase(struct mtd_info *mtd, int page)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	unsigned int eraseblock;
+
+	/* Send commands to erase a block */
+	eraseblock = page >> (chip->phys_erase_shift - chip->page_shift);
+
+	return nand_erase_op(chip, eraseblock);
+}
+
+/**
+ * nand_erase - [MTD Interface] erase block(s)
+ * @mtd: MTD device structure
+ * @instr: erase instruction
+ *
+ * Erase one ore more blocks.
+ */
+static int nand_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	return nand_erase_nand(mtd, instr, 0);
+}
+
+/**
+ * nand_erase_nand - [INTERN] erase block(s)
+ * @mtd: MTD device structure
+ * @instr: erase instruction
+ * @allowbbt: allow erasing the bbt area
+ *
+ * Erase one ore more blocks.
+ */
+int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
+		    int allowbbt)
+{
+	int page, status, pages_per_block, ret, chipnr;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	loff_t len;
+
+	pr_debug("%s: start = 0x%012llx, len = %llu\n",
+			__func__, (unsigned long long)instr->addr,
+			(unsigned long long)instr->len);
+
+	if (check_offs_len(mtd, instr->addr, instr->len))
+		return -EINVAL;
+
+	/* Grab the lock and see if the device is available */
+	nand_get_device(mtd, FL_ERASING);
+
+	/* Shift to get first page */
+	page = (int)(instr->addr >> chip->page_shift);
+	chipnr = (int)(instr->addr >> chip->chip_shift);
+
+	/* Calculate pages in each block */
+	pages_per_block = 1 << (chip->phys_erase_shift - chip->page_shift);
+
+	/* Select the NAND device */
+	chip->select_chip(mtd, chipnr);
+
+	/* Check, if it is write protected */
+	if (nand_check_wp(mtd)) {
+		pr_debug("%s: device is write protected!\n",
+				__func__);
+		ret = -EIO;
+		goto erase_exit;
+	}
+
+	/* Loop through the pages */
+	len = instr->len;
+
+	while (len) {
+		/* Check if we have a bad block, we do not erase bad blocks! */
+		if (nand_block_checkbad(mtd, ((loff_t) page) <<
+					chip->page_shift, allowbbt)) {
+			pr_warn("%s: attempt to erase a bad block at page 0x%08x\n",
+				    __func__, page);
+			ret = -EIO;
+			goto erase_exit;
+		}
+
+		/*
+		 * Invalidate the page cache, if we erase the block which
+		 * contains the current cached page.
+		 */
+		if (page <= chip->pagebuf && chip->pagebuf <
+		    (page + pages_per_block))
+			chip->pagebuf = -1;
+
+		status = chip->erase(mtd, page & chip->pagemask);
+
+		/* See if block erase succeeded */
+		if (status) {
+			pr_debug("%s: failed erase, page 0x%08x\n",
+					__func__, page);
+			ret = -EIO;
+			instr->fail_addr =
+				((loff_t)page << chip->page_shift);
+			goto erase_exit;
+		}
+
+		/* Increment page address and decrement length */
+		len -= (1ULL << chip->phys_erase_shift);
+		page += pages_per_block;
+
+		/* Check, if we cross a chip boundary */
+		if (len && !(page & chip->pagemask)) {
+			chipnr++;
+			chip->select_chip(mtd, -1);
+			chip->select_chip(mtd, chipnr);
+		}
+	}
+
+	ret = 0;
+erase_exit:
+
+	/* Deselect and wake up anyone waiting on the device */
+	chip->select_chip(mtd, -1);
+	nand_release_device(mtd);
+
+	/* Return more or less happy */
+	return ret;
+}
+
+/**
+ * nand_sync - [MTD Interface] sync
+ * @mtd: MTD device structure
+ *
+ * Sync is actually a wait for chip ready function.
+ */
+static void nand_sync(struct mtd_info *mtd)
+{
+	pr_debug("%s: called\n", __func__);
+
+	/* Grab the lock and see if the device is available */
+	nand_get_device(mtd, FL_SYNCING);
+	/* Release it and go back */
+	nand_release_device(mtd);
+}
+
+/**
+ * nand_block_isbad - [MTD Interface] Check if block at offset is bad
+ * @mtd: MTD device structure
+ * @offs: offset relative to mtd start
+ */
+static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int chipnr = (int)(offs >> chip->chip_shift);
+	int ret;
+
+	/* Select the NAND device */
+	nand_get_device(mtd, FL_READING);
+	chip->select_chip(mtd, chipnr);
+
+	ret = nand_block_checkbad(mtd, offs, 0);
+
+	chip->select_chip(mtd, -1);
+	nand_release_device(mtd);
+
+	return ret;
+}
+
+/**
+ * nand_block_markbad - [MTD Interface] Mark block at the given offset as bad
+ * @mtd: MTD device structure
+ * @ofs: offset relative to mtd start
+ */
+static int nand_block_markbad(struct mtd_info *mtd, loff_t ofs)
+{
+	int ret;
+
+	ret = nand_block_isbad(mtd, ofs);
+	if (ret) {
+		/* If it was bad already, return success and do nothing */
+		if (ret > 0)
+			return 0;
+		return ret;
+	}
+
+	return nand_block_markbad_lowlevel(mtd, ofs);
+}
+
+/**
+ * nand_max_bad_blocks - [MTD Interface] Max number of bad blocks for an mtd
+ * @mtd: MTD device structure
+ * @ofs: offset relative to mtd start
+ * @len: length of mtd
+ */
+static int nand_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	u32 part_start_block;
+	u32 part_end_block;
+	u32 part_start_die;
+	u32 part_end_die;
+
+	/*
+	 * max_bb_per_die and blocks_per_die used to determine
+	 * the maximum bad block count.
+	 */
+	if (!chip->max_bb_per_die || !chip->blocks_per_die)
+		return -ENOTSUPP;
+
+	/* Get the start and end of the partition in erase blocks. */
+	part_start_block = mtd_div_by_eb(ofs, mtd);
+	part_end_block = mtd_div_by_eb(len, mtd) + part_start_block - 1;
+
+	/* Get the start and end LUNs of the partition. */
+	part_start_die = part_start_block / chip->blocks_per_die;
+	part_end_die = part_end_block / chip->blocks_per_die;
+
+	/*
+	 * Look up the bad blocks per unit and multiply by the number of units
+	 * that the partition spans.
+	 */
+	return chip->max_bb_per_die * (part_end_die - part_start_die + 1);
+}
+
+/**
+ * nand_default_set_features- [REPLACEABLE] set NAND chip features
+ * @mtd: MTD device structure
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ */
+static int nand_default_set_features(struct mtd_info *mtd,
+				     struct nand_chip *chip, int addr,
+				     uint8_t *subfeature_param)
+{
+	return nand_set_features_op(chip, addr, subfeature_param);
+}
+
+/**
+ * nand_default_get_features- [REPLACEABLE] get NAND chip features
+ * @mtd: MTD device structure
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ */
+static int nand_default_get_features(struct mtd_info *mtd,
+				     struct nand_chip *chip, int addr,
+				     uint8_t *subfeature_param)
+{
+	return nand_get_features_op(chip, addr, subfeature_param);
+}
+
+/**
+ * nand_get_set_features_notsupp - set/get features stub returning -ENOTSUPP
+ * @mtd: MTD device structure
+ * @chip: nand chip info structure
+ * @addr: feature address.
+ * @subfeature_param: the subfeature parameters, a four bytes array.
+ *
+ * Should be used by NAND controller drivers that do not support the SET/GET
+ * FEATURES operations.
+ */
+int nand_get_set_features_notsupp(struct mtd_info *mtd, struct nand_chip *chip,
+				  int addr, u8 *subfeature_param)
+{
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL(nand_get_set_features_notsupp);
+
+/**
+ * nand_suspend - [MTD Interface] Suspend the NAND flash
+ * @mtd: MTD device structure
+ */
+static int nand_suspend(struct mtd_info *mtd)
+{
+	return nand_get_device(mtd, FL_PM_SUSPENDED);
+}
+
+/**
+ * nand_resume - [MTD Interface] Resume the NAND flash
+ * @mtd: MTD device structure
+ */
+static void nand_resume(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (chip->state == FL_PM_SUSPENDED)
+		nand_release_device(mtd);
+	else
+		pr_err("%s called for a chip which is not in suspended state\n",
+			__func__);
+}
+
+/**
+ * nand_shutdown - [MTD Interface] Finish the current NAND operation and
+ *                 prevent further operations
+ * @mtd: MTD device structure
+ */
+static void nand_shutdown(struct mtd_info *mtd)
+{
+	nand_get_device(mtd, FL_PM_SUSPENDED);
+}
+
+/* Set default functions */
+static void nand_set_defaults(struct nand_chip *chip)
+{
+	unsigned int busw = chip->options & NAND_BUSWIDTH_16;
+
+	/* check for proper chip_delay setup, set 20us if not */
+	if (!chip->chip_delay)
+		chip->chip_delay = 20;
+
+	/* check, if a user supplied command function given */
+	if (!chip->cmdfunc && !chip->exec_op)
+		chip->cmdfunc = nand_command;
+
+	/* check, if a user supplied wait function given */
+	if (chip->waitfunc == NULL)
+		chip->waitfunc = nand_wait;
+
+	if (!chip->select_chip)
+		chip->select_chip = nand_select_chip;
+
+	/* set for ONFI nand */
+	if (!chip->set_features)
+		chip->set_features = nand_default_set_features;
+	if (!chip->get_features)
+		chip->get_features = nand_default_get_features;
+
+	/* If called twice, pointers that depend on busw may need to be reset */
+	if (!chip->read_byte || chip->read_byte == nand_read_byte)
+		chip->read_byte = busw ? nand_read_byte16 : nand_read_byte;
+	if (!chip->read_word)
+		chip->read_word = nand_read_word;
+	if (!chip->block_bad)
+		chip->block_bad = nand_block_bad;
+	if (!chip->block_markbad)
+		chip->block_markbad = nand_default_block_markbad;
+	if (!chip->write_buf || chip->write_buf == nand_write_buf)
+		chip->write_buf = busw ? nand_write_buf16 : nand_write_buf;
+	if (!chip->write_byte || chip->write_byte == nand_write_byte)
+		chip->write_byte = busw ? nand_write_byte16 : nand_write_byte;
+	if (!chip->read_buf || chip->read_buf == nand_read_buf)
+		chip->read_buf = busw ? nand_read_buf16 : nand_read_buf;
+	if (!chip->scan_bbt)
+		chip->scan_bbt = nand_default_bbt;
+
+	if (!chip->controller) {
+		chip->controller = &chip->hwcontrol;
+		nand_hw_control_init(chip->controller);
+	}
+
+	if (!chip->buf_align)
+		chip->buf_align = 1;
+}
+
+/* Sanitize ONFI strings so we can safely print them */
+static void sanitize_string(uint8_t *s, size_t len)
+{
+	ssize_t i;
+
+	/* Null terminate */
+	s[len - 1] = 0;
+
+	/* Remove non printable chars */
+	for (i = 0; i < len - 1; i++) {
+		if (s[i] < ' ' || s[i] > 127)
+			s[i] = '?';
+	}
+
+	/* Remove trailing spaces */
+	strim(s);
+}
+
+static u16 onfi_crc16(u16 crc, u8 const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++ << 8;
+		for (i = 0; i < 8; i++)
+			crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
+	}
+
+	return crc;
+}
+
+/* Parse the Extended Parameter Page. */
+static int nand_flash_detect_ext_param_page(struct nand_chip *chip,
+					    struct nand_onfi_params *p)
+{
+	struct onfi_ext_param_page *ep;
+	struct onfi_ext_section *s;
+	struct onfi_ext_ecc_info *ecc;
+	uint8_t *cursor;
+	int ret;
+	int len;
+	int i;
+
+	len = le16_to_cpu(p->ext_param_page_length) * 16;
+	ep = kmalloc(len, GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+
+	/* Send our own NAND_CMD_PARAM. */
+	ret = nand_read_param_page_op(chip, 0, NULL, 0);
+	if (ret)
+		goto ext_out;
+
+	/* Use the Change Read Column command to skip the ONFI param pages. */
+	ret = nand_change_read_column_op(chip,
+					 sizeof(*p) * p->num_of_param_pages,
+					 ep, len, true);
+	if (ret)
+		goto ext_out;
+
+	ret = -EINVAL;
+	if ((onfi_crc16(ONFI_CRC_BASE, ((uint8_t *)ep) + 2, len - 2)
+		!= le16_to_cpu(ep->crc))) {
+		pr_debug("fail in the CRC.\n");
+		goto ext_out;
+	}
+
+	/*
+	 * Check the signature.
+	 * Do not strictly follow the ONFI spec, maybe changed in future.
+	 */
+	if (strncmp(ep->sig, "EPPS", 4)) {
+		pr_debug("The signature is invalid.\n");
+		goto ext_out;
+	}
+
+	/* find the ECC section. */
+	cursor = (uint8_t *)(ep + 1);
+	for (i = 0; i < ONFI_EXT_SECTION_MAX; i++) {
+		s = ep->sections + i;
+		if (s->type == ONFI_SECTION_TYPE_2)
+			break;
+		cursor += s->length * 16;
+	}
+	if (i == ONFI_EXT_SECTION_MAX) {
+		pr_debug("We can not find the ECC section.\n");
+		goto ext_out;
+	}
+
+	/* get the info we want. */
+	ecc = (struct onfi_ext_ecc_info *)cursor;
+
+	if (!ecc->codeword_size) {
+		pr_debug("Invalid codeword size\n");
+		goto ext_out;
+	}
+
+	chip->ecc_strength_ds = ecc->ecc_bits;
+	chip->ecc_step_ds = 1 << ecc->codeword_size;
+	ret = 0;
+
+ext_out:
+	kfree(ep);
+	return ret;
+}
+
+/*
+ * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
+ */
+static int nand_flash_detect_onfi(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct nand_onfi_params *p;
+	char id[4];
+	int i, ret, val;
+
+	/* Try ONFI for unknown chip or LP */
+	ret = nand_readid_op(chip, 0x20, id, sizeof(id));
+	if (ret || strncmp(id, "ONFI", 4))
+		return 0;
+
+	/* ONFI chip: allocate a buffer to hold its parameter page */
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	ret = nand_read_param_page_op(chip, 0, NULL, 0);
+	if (ret) {
+		ret = 0;
+		goto free_onfi_param_page;
+	}
+
+	for (i = 0; i < 3; i++) {
+		ret = nand_read_data_op(chip, p, sizeof(*p), true);
+		if (ret) {
+			ret = 0;
+			goto free_onfi_param_page;
+		}
+
+		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
+				le16_to_cpu(p->crc)) {
+			break;
+		}
+	}
+
+	if (i == 3) {
+		pr_err("Could not find valid ONFI parameter page; aborting\n");
+		goto free_onfi_param_page;
+	}
+
+	/* Check version */
+	val = le16_to_cpu(p->revision);
+	if (val & (1 << 5))
+		chip->parameters.onfi.version = 23;
+	else if (val & (1 << 4))
+		chip->parameters.onfi.version = 22;
+	else if (val & (1 << 3))
+		chip->parameters.onfi.version = 21;
+	else if (val & (1 << 2))
+		chip->parameters.onfi.version = 20;
+	else if (val & (1 << 1))
+		chip->parameters.onfi.version = 10;
+
+	if (!chip->parameters.onfi.version) {
+		pr_info("unsupported ONFI version: %d\n", val);
+		goto free_onfi_param_page;
+	} else {
+		ret = 1;
+	}
+
+	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
+	sanitize_string(p->model, sizeof(p->model));
+	strncpy(chip->parameters.model, p->model,
+		sizeof(chip->parameters.model) - 1);
+
+	mtd->writesize = le32_to_cpu(p->byte_per_page);
+
+	/*
+	 * pages_per_block and blocks_per_lun may not be a power-of-2 size
+	 * (don't ask me who thought of this...). MTD assumes that these
+	 * dimensions will be power-of-2, so just truncate the remaining area.
+	 */
+	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
+	mtd->erasesize *= mtd->writesize;
+
+	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+
+	/* See erasesize comment */
+	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
+	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
+	chip->bits_per_cell = p->bits_per_cell;
+
+	chip->max_bb_per_die = le16_to_cpu(p->bb_per_lun);
+	chip->blocks_per_die = le32_to_cpu(p->blocks_per_lun);
+
+	if (le16_to_cpu(p->features) & ONFI_FEATURE_16_BIT_BUS)
+		chip->options |= NAND_BUSWIDTH_16;
+
+	if (p->ecc_bits != 0xff) {
+		chip->ecc_strength_ds = p->ecc_bits;
+		chip->ecc_step_ds = 512;
+	} else if (chip->parameters.onfi.version >= 21 &&
+		(le16_to_cpu(p->features) & ONFI_FEATURE_EXT_PARAM_PAGE)) {
+
+		/*
+		 * The nand_flash_detect_ext_param_page() uses the
+		 * Change Read Column command which maybe not supported
+		 * by the chip->cmdfunc. So try to update the chip->cmdfunc
+		 * now. We do not replace user supplied command function.
+		 */
+		if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
+			chip->cmdfunc = nand_command_lp;
+
+		/* The Extended Parameter Page is supported since ONFI 2.1. */
+		if (nand_flash_detect_ext_param_page(chip, p))
+			pr_warn("Failed to detect ONFI extended param page\n");
+	} else {
+		pr_warn("Could not retrieve ONFI ECC requirements\n");
+	}
+
+	/* Save some parameters from the parameter page for future use */
+	if (le16_to_cpu(p->opt_cmd) & ONFI_OPT_CMD_SET_GET_FEATURES) {
+		chip->parameters.supports_set_get_features = true;
+		bitmap_set(chip->parameters.get_feature_list,
+			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
+		bitmap_set(chip->parameters.set_feature_list,
+			   ONFI_FEATURE_ADDR_TIMING_MODE, 1);
+	}
+	chip->parameters.onfi.tPROG = le16_to_cpu(p->t_prog);
+	chip->parameters.onfi.tBERS = le16_to_cpu(p->t_bers);
+	chip->parameters.onfi.tR = le16_to_cpu(p->t_r);
+	chip->parameters.onfi.tCCS = le16_to_cpu(p->t_ccs);
+	chip->parameters.onfi.async_timing_mode =
+		le16_to_cpu(p->async_timing_mode);
+	chip->parameters.onfi.vendor_revision =
+		le16_to_cpu(p->vendor_revision);
+	memcpy(chip->parameters.onfi.vendor, p->vendor,
+	       sizeof(p->vendor));
+
+free_onfi_param_page:
+	kfree(p);
+	return ret;
+}
+
+/*
+ * Check if the NAND chip is JEDEC compliant, returns 1 if it is, 0 otherwise.
+ */
+static int nand_flash_detect_jedec(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct nand_jedec_params *p;
+	struct jedec_ecc_info *ecc;
+	int jedec_version = 0;
+	char id[5];
+	int i, val, ret;
+
+	/* Try JEDEC for unknown chip or LP */
+	ret = nand_readid_op(chip, 0x40, id, sizeof(id));
+	if (ret || strncmp(id, "JEDEC", sizeof(id)))
+		return 0;
+
+	/* JEDEC chip: allocate a buffer to hold its parameter page */
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	ret = nand_read_param_page_op(chip, 0x40, NULL, 0);
+	if (ret) {
+		ret = 0;
+		goto free_jedec_param_page;
+	}
+
+	for (i = 0; i < 3; i++) {
+		ret = nand_read_data_op(chip, p, sizeof(*p), true);
+		if (ret) {
+			ret = 0;
+			goto free_jedec_param_page;
+		}
+
+		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 510) ==
+				le16_to_cpu(p->crc))
+			break;
+	}
+
+	if (i == 3) {
+		pr_err("Could not find valid JEDEC parameter page; aborting\n");
+		goto free_jedec_param_page;
+	}
+
+	/* Check version */
+	val = le16_to_cpu(p->revision);
+	if (val & (1 << 2))
+		jedec_version = 10;
+	else if (val & (1 << 1))
+		jedec_version = 1; /* vendor specific version */
+
+	if (!jedec_version) {
+		pr_info("unsupported JEDEC version: %d\n", val);
+		goto free_jedec_param_page;
+	}
+
+	sanitize_string(p->manufacturer, sizeof(p->manufacturer));
+	sanitize_string(p->model, sizeof(p->model));
+	strncpy(chip->parameters.model, p->model,
+		sizeof(chip->parameters.model) - 1);
+
+	mtd->writesize = le32_to_cpu(p->byte_per_page);
+
+	/* Please reference to the comment for nand_flash_detect_onfi. */
+	mtd->erasesize = 1 << (fls(le32_to_cpu(p->pages_per_block)) - 1);
+	mtd->erasesize *= mtd->writesize;
+
+	mtd->oobsize = le16_to_cpu(p->spare_bytes_per_page);
+
+	/* Please reference to the comment for nand_flash_detect_onfi. */
+	chip->chipsize = 1 << (fls(le32_to_cpu(p->blocks_per_lun)) - 1);
+	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
+	chip->bits_per_cell = p->bits_per_cell;
+
+	if (le16_to_cpu(p->features) & JEDEC_FEATURE_16_BIT_BUS)
+		chip->options |= NAND_BUSWIDTH_16;
+
+	/* ECC info */
+	ecc = &p->ecc_info[0];
+
+	if (ecc->codeword_size >= 9) {
+		chip->ecc_strength_ds = ecc->ecc_bits;
+		chip->ecc_step_ds = 1 << ecc->codeword_size;
+	} else {
+		pr_warn("Invalid codeword size\n");
+	}
+
+free_jedec_param_page:
+	kfree(p);
+	return ret;
+}
+
+/*
+ * nand_id_has_period - Check if an ID string has a given wraparound period
+ * @id_data: the ID string
+ * @arrlen: the length of the @id_data array
+ * @period: the period of repitition
+ *
+ * Check if an ID string is repeated within a given sequence of bytes at
+ * specific repetition interval period (e.g., {0x20,0x01,0x7F,0x20} has a
+ * period of 3). This is a helper function for nand_id_len(). Returns non-zero
+ * if the repetition has a period of @period; otherwise, returns zero.
+ */
+static int nand_id_has_period(u8 *id_data, int arrlen, int period)
+{
+	int i, j;
+	for (i = 0; i < period; i++)
+		for (j = i + period; j < arrlen; j += period)
+			if (id_data[i] != id_data[j])
+				return 0;
+	return 1;
+}
+
+/*
+ * nand_id_len - Get the length of an ID string returned by CMD_READID
+ * @id_data: the ID string
+ * @arrlen: the length of the @id_data array
+
+ * Returns the length of the ID string, according to known wraparound/trailing
+ * zero patterns. If no pattern exists, returns the length of the array.
+ */
+static int nand_id_len(u8 *id_data, int arrlen)
+{
+	int last_nonzero, period;
+
+	/* Find last non-zero byte */
+	for (last_nonzero = arrlen - 1; last_nonzero >= 0; last_nonzero--)
+		if (id_data[last_nonzero])
+			break;
+
+	/* All zeros */
+	if (last_nonzero < 0)
+		return 0;
+
+	/* Calculate wraparound period */
+	for (period = 1; period < arrlen; period++)
+		if (nand_id_has_period(id_data, arrlen, period))
+			break;
+
+	/* There's a repeated pattern */
+	if (period < arrlen)
+		return period;
+
+	/* There are trailing zeros */
+	if (last_nonzero < arrlen - 1)
+		return last_nonzero + 1;
+
+	/* No pattern detected */
+	return arrlen;
+}
+
+/* Extract the bits of per cell from the 3rd byte of the extended ID */
+static int nand_get_bits_per_cell(u8 cellinfo)
+{
+	int bits;
+
+	bits = cellinfo & NAND_CI_CELLTYPE_MSK;
+	bits >>= NAND_CI_CELLTYPE_SHIFT;
+	return bits + 1;
+}
+
+/*
+ * Many new NAND share similar device ID codes, which represent the size of the
+ * chip. The rest of the parameters must be decoded according to generic or
+ * manufacturer-specific "extended ID" decoding patterns.
+ */
+void nand_decode_ext_id(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int extid;
+	u8 *id_data = chip->id.data;
+	/* The 3rd id byte holds MLC / multichip data */
+	chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
+	/* The 4th id byte is the important one */
+	extid = id_data[3];
+
+	/* Calc pagesize */
+	mtd->writesize = 1024 << (extid & 0x03);
+	extid >>= 2;
+	/* Calc oobsize */
+	mtd->oobsize = (8 << (extid & 0x01)) * (mtd->writesize >> 9);
+	extid >>= 2;
+	/* Calc blocksize. Blocksize is multiples of 64KiB */
+	mtd->erasesize = (64 * 1024) << (extid & 0x03);
+	extid >>= 2;
+	/* Get buswidth information */
+	if (extid & 0x1)
+		chip->options |= NAND_BUSWIDTH_16;
+}
+EXPORT_SYMBOL_GPL(nand_decode_ext_id);
+
+/*
+ * Old devices have chip data hardcoded in the device ID table. nand_decode_id
+ * decodes a matching ID table entry and assigns the MTD size parameters for
+ * the chip.
+ */
+static void nand_decode_id(struct nand_chip *chip, struct nand_flash_dev *type)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	mtd->erasesize = type->erasesize;
+	mtd->writesize = type->pagesize;
+	mtd->oobsize = mtd->writesize / 32;
+
+	/* All legacy ID NAND are small-page, SLC */
+	chip->bits_per_cell = 1;
+}
+
+/*
+ * Set the bad block marker/indicator (BBM/BBI) patterns according to some
+ * heuristic patterns using various detected parameters (e.g., manufacturer,
+ * page size, cell-type information).
+ */
+static void nand_decode_bbm_options(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	/* Set the bad block position */
+	if (mtd->writesize > 512 || (chip->options & NAND_BUSWIDTH_16))
+		chip->badblockpos = NAND_LARGE_BADBLOCK_POS;
+	else
+		chip->badblockpos = NAND_SMALL_BADBLOCK_POS;
+}
+
+static inline bool is_full_id_nand(struct nand_flash_dev *type)
+{
+	return type->id_len;
+}
+
+static bool find_full_id_nand(struct nand_chip *chip,
+			      struct nand_flash_dev *type)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u8 *id_data = chip->id.data;
+
+	if (!strncmp(type->id, id_data, type->id_len)) {
+		mtd->writesize = type->pagesize;
+		mtd->erasesize = type->erasesize;
+		mtd->oobsize = type->oobsize;
+
+		chip->bits_per_cell = nand_get_bits_per_cell(id_data[2]);
+		chip->chipsize = (uint64_t)type->chipsize << 20;
+		chip->options |= type->options;
+		chip->ecc_strength_ds = NAND_ECC_STRENGTH(type);
+		chip->ecc_step_ds = NAND_ECC_STEP(type);
+		chip->onfi_timing_mode_default =
+					type->onfi_timing_mode_default;
+
+		strncpy(chip->parameters.model, type->name,
+			sizeof(chip->parameters.model) - 1);
+
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Manufacturer detection. Only used when the NAND is not ONFI or JEDEC
+ * compliant and does not have a full-id or legacy-id entry in the nand_ids
+ * table.
+ */
+static void nand_manufacturer_detect(struct nand_chip *chip)
+{
+	/*
+	 * Try manufacturer detection if available and use
+	 * nand_decode_ext_id() otherwise.
+	 */
+	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
+	    chip->manufacturer.desc->ops->detect) {
+		/* The 3rd id byte holds MLC / multichip data */
+		chip->bits_per_cell = nand_get_bits_per_cell(chip->id.data[2]);
+		chip->manufacturer.desc->ops->detect(chip);
+	} else {
+		nand_decode_ext_id(chip);
+	}
+}
+
+/*
+ * Manufacturer initialization. This function is called for all NANDs including
+ * ONFI and JEDEC compliant ones.
+ * Manufacturer drivers should put all their specific initialization code in
+ * their ->init() hook.
+ */
+static int nand_manufacturer_init(struct nand_chip *chip)
+{
+	if (!chip->manufacturer.desc || !chip->manufacturer.desc->ops ||
+	    !chip->manufacturer.desc->ops->init)
+		return 0;
+
+	return chip->manufacturer.desc->ops->init(chip);
+}
+
+/*
+ * Manufacturer cleanup. This function is called for all NANDs including
+ * ONFI and JEDEC compliant ones.
+ * Manufacturer drivers should put all their specific cleanup code in their
+ * ->cleanup() hook.
+ */
+static void nand_manufacturer_cleanup(struct nand_chip *chip)
+{
+	/* Release manufacturer private data */
+	if (chip->manufacturer.desc && chip->manufacturer.desc->ops &&
+	    chip->manufacturer.desc->ops->cleanup)
+		chip->manufacturer.desc->ops->cleanup(chip);
+}
+
+/*
+ * Get the flash and manufacturer id and lookup if the type is supported.
+ */
+static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
+{
+	const struct nand_manufacturer *manufacturer;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int busw, ret;
+	u8 *id_data = chip->id.data;
+	u8 maf_id, dev_id;
+
+	/*
+	 * Reset the chip, required by some chips (e.g. Micron MT29FxGxxxxx)
+	 * after power-up.
+	 */
+	ret = nand_reset(chip, 0);
+	if (ret)
+		return ret;
+
+	/* Select the device */
+	chip->select_chip(mtd, 0);
+
+	/* Send the command for reading device ID */
+	ret = nand_readid_op(chip, 0, id_data, 2);
+	if (ret)
+		return ret;
+
+	/* Read manufacturer and device IDs */
+	maf_id = id_data[0];
+	dev_id = id_data[1];
+
+	/*
+	 * Try again to make sure, as some systems the bus-hold or other
+	 * interface concerns can cause random data which looks like a
+	 * possibly credible NAND flash to appear. If the two results do
+	 * not match, ignore the device completely.
+	 */
+
+	/* Read entire ID string */
+	ret = nand_readid_op(chip, 0, id_data, sizeof(chip->id.data));
+	if (ret)
+		return ret;
+
+	if (id_data[0] != maf_id || id_data[1] != dev_id) {
+		pr_info("second ID read did not match %02x,%02x against %02x,%02x\n",
+			maf_id, dev_id, id_data[0], id_data[1]);
+		return -ENODEV;
+	}
+
+	chip->id.len = nand_id_len(id_data, ARRAY_SIZE(chip->id.data));
+
+	/* Try to identify manufacturer */
+	manufacturer = nand_get_manufacturer(maf_id);
+	chip->manufacturer.desc = manufacturer;
+
+	if (!type)
+		type = nand_flash_ids;
+
+	/*
+	 * Save the NAND_BUSWIDTH_16 flag before letting auto-detection logic
+	 * override it.
+	 * This is required to make sure initial NAND bus width set by the
+	 * NAND controller driver is coherent with the real NAND bus width
+	 * (extracted by auto-detection code).
+	 */
+	busw = chip->options & NAND_BUSWIDTH_16;
+
+	/*
+	 * The flag is only set (never cleared), reset it to its default value
+	 * before starting auto-detection.
+	 */
+	chip->options &= ~NAND_BUSWIDTH_16;
+
+	for (; type->name != NULL; type++) {
+		if (is_full_id_nand(type)) {
+			if (find_full_id_nand(chip, type))
+				goto ident_done;
+		} else if (dev_id == type->dev_id) {
+			break;
+		}
+	}
+
+	chip->parameters.onfi.version = 0;
+	if (!type->name || !type->pagesize) {
+		/* Check if the chip is ONFI compliant */
+		ret = nand_flash_detect_onfi(chip);
+		if (ret < 0)
+			return ret;
+		else if (ret)
+			goto ident_done;
+
+		/* Check if the chip is JEDEC compliant */
+		ret = nand_flash_detect_jedec(chip);
+		if (ret < 0)
+			return ret;
+		else if (ret)
+			goto ident_done;
+	}
+
+	if (!type->name)
+		return -ENODEV;
+
+	strncpy(chip->parameters.model, type->name,
+		sizeof(chip->parameters.model) - 1);
+
+	chip->chipsize = (uint64_t)type->chipsize << 20;
+
+	if (!type->pagesize)
+		nand_manufacturer_detect(chip);
+	else
+		nand_decode_id(chip, type);
+
+	/* Get chip options */
+	chip->options |= type->options;
+
+ident_done:
+	if (!mtd->name)
+		mtd->name = chip->parameters.model;
+
+	if (chip->options & NAND_BUSWIDTH_AUTO) {
+		WARN_ON(busw & NAND_BUSWIDTH_16);
+		nand_set_defaults(chip);
+	} else if (busw != (chip->options & NAND_BUSWIDTH_16)) {
+		/*
+		 * Check, if buswidth is correct. Hardware drivers should set
+		 * chip correct!
+		 */
+		pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
+			maf_id, dev_id);
+		pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
+			mtd->name);
+		pr_warn("bus width %d instead of %d bits\n", busw ? 16 : 8,
+			(chip->options & NAND_BUSWIDTH_16) ? 16 : 8);
+		return -EINVAL;
+	}
+
+	nand_decode_bbm_options(chip);
+
+	/* Calculate the address shift from the page size */
+	chip->page_shift = ffs(mtd->writesize) - 1;
+	/* Convert chipsize to number of pages per chip -1 */
+	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
+
+	chip->bbt_erase_shift = chip->phys_erase_shift =
+		ffs(mtd->erasesize) - 1;
+	if (chip->chipsize & 0xffffffff)
+		chip->chip_shift = ffs((unsigned)chip->chipsize) - 1;
+	else {
+		chip->chip_shift = ffs((unsigned)(chip->chipsize >> 32));
+		chip->chip_shift += 32 - 1;
+	}
+
+	if (chip->chip_shift - chip->page_shift > 16)
+		chip->options |= NAND_ROW_ADDR_3;
+
+	chip->badblockbits = 8;
+	chip->erase = single_erase;
+
+	/* Do not replace user supplied command function! */
+	if (mtd->writesize > 512 && chip->cmdfunc == nand_command)
+		chip->cmdfunc = nand_command_lp;
+
+	pr_info("device found, Manufacturer ID: 0x%02x, Chip ID: 0x%02x\n",
+		maf_id, dev_id);
+	pr_info("%s %s\n", nand_manufacturer_name(manufacturer),
+		chip->parameters.model);
+	pr_info("%d MiB, %s, erase size: %d KiB, page size: %d, OOB size: %d\n",
+		(int)(chip->chipsize >> 20), nand_is_slc(chip) ? "SLC" : "MLC",
+		mtd->erasesize >> 10, mtd->writesize, mtd->oobsize);
+	return 0;
+}
+
+static const char * const nand_ecc_modes[] = {
+	[NAND_ECC_NONE]		= "none",
+	[NAND_ECC_SOFT]		= "soft",
+	[NAND_ECC_HW]		= "hw",
+	[NAND_ECC_HW_SYNDROME]	= "hw_syndrome",
+	[NAND_ECC_HW_OOB_FIRST]	= "hw_oob_first",
+	[NAND_ECC_ON_DIE]	= "on-die",
+};
+
+static int of_get_nand_ecc_mode(struct device_node *np)
+{
+	const char *pm;
+	int err, i;
+
+	err = of_property_read_string(np, "nand-ecc-mode", &pm);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
+		if (!strcasecmp(pm, nand_ecc_modes[i]))
+			return i;
+
+	/*
+	 * For backward compatibility we support few obsoleted values that don't
+	 * have their mappings into nand_ecc_modes_t anymore (they were merged
+	 * with other enums).
+	 */
+	if (!strcasecmp(pm, "soft_bch"))
+		return NAND_ECC_SOFT;
+
+	return -ENODEV;
+}
+
+static const char * const nand_ecc_algos[] = {
+	[NAND_ECC_HAMMING]	= "hamming",
+	[NAND_ECC_BCH]		= "bch",
+};
+
+static int of_get_nand_ecc_algo(struct device_node *np)
+{
+	const char *pm;
+	int err, i;
+
+	err = of_property_read_string(np, "nand-ecc-algo", &pm);
+	if (!err) {
+		for (i = NAND_ECC_HAMMING; i < ARRAY_SIZE(nand_ecc_algos); i++)
+			if (!strcasecmp(pm, nand_ecc_algos[i]))
+				return i;
+		return -ENODEV;
+	}
+
+	/*
+	 * For backward compatibility we also read "nand-ecc-mode" checking
+	 * for some obsoleted values that were specifying ECC algorithm.
+	 */
+	err = of_property_read_string(np, "nand-ecc-mode", &pm);
+	if (err < 0)
+		return err;
+
+	if (!strcasecmp(pm, "soft"))
+		return NAND_ECC_HAMMING;
+	else if (!strcasecmp(pm, "soft_bch"))
+		return NAND_ECC_BCH;
+
+	return -ENODEV;
+}
+
+static int of_get_nand_ecc_step_size(struct device_node *np)
+{
+	int ret;
+	u32 val;
+
+	ret = of_property_read_u32(np, "nand-ecc-step-size", &val);
+	return ret ? ret : val;
+}
+
+static int of_get_nand_ecc_strength(struct device_node *np)
+{
+	int ret;
+	u32 val;
+
+	ret = of_property_read_u32(np, "nand-ecc-strength", &val);
+	return ret ? ret : val;
+}
+
+static int of_get_nand_bus_width(struct device_node *np)
+{
+	u32 val;
+
+	if (of_property_read_u32(np, "nand-bus-width", &val))
+		return 8;
+
+	switch (val) {
+	case 8:
+	case 16:
+		return val;
+	default:
+		return -EIO;
+	}
+}
+
+static bool of_get_nand_on_flash_bbt(struct device_node *np)
+{
+	return of_property_read_bool(np, "nand-on-flash-bbt");
+}
+
+static int nand_dt_init(struct nand_chip *chip)
+{
+	struct device_node *dn = nand_get_flash_node(chip);
+	int ecc_mode, ecc_algo, ecc_strength, ecc_step;
+
+	if (!dn)
+		return 0;
+
+	if (of_get_nand_bus_width(dn) == 16)
+		chip->options |= NAND_BUSWIDTH_16;
+
+	if (of_get_nand_on_flash_bbt(dn))
+		chip->bbt_options |= NAND_BBT_USE_FLASH;
+
+	ecc_mode = of_get_nand_ecc_mode(dn);
+	ecc_algo = of_get_nand_ecc_algo(dn);
+	ecc_strength = of_get_nand_ecc_strength(dn);
+	ecc_step = of_get_nand_ecc_step_size(dn);
+
+	if (ecc_mode >= 0)
+		chip->ecc.mode = ecc_mode;
+
+	if (ecc_algo >= 0)
+		chip->ecc.algo = ecc_algo;
+
+	if (ecc_strength >= 0)
+		chip->ecc.strength = ecc_strength;
+
+	if (ecc_step > 0)
+		chip->ecc.size = ecc_step;
+
+	if (of_property_read_bool(dn, "nand-ecc-maximize"))
+		chip->ecc.options |= NAND_ECC_MAXIMIZE;
+
+	return 0;
+}
+
+/**
+ * nand_scan_ident - [NAND Interface] Scan for the NAND device
+ * @mtd: MTD device structure
+ * @maxchips: number of chips to scan for
+ * @table: alternative NAND ID table
+ *
+ * This is the first phase of the normal nand_scan() function. It reads the
+ * flash ID and sets up MTD fields accordingly.
+ *
+ */
+int nand_scan_ident(struct mtd_info *mtd, int maxchips,
+		    struct nand_flash_dev *table)
+{
+	int i, nand_maf_id, nand_dev_id;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	int ret;
+
+	/* Enforce the right timings for reset/detection */
+	onfi_fill_data_interface(chip, NAND_SDR_IFACE, 0);
+
+	ret = nand_dt_init(chip);
+	if (ret)
+		return ret;
+
+	if (!mtd->name && mtd->dev.parent)
+		mtd->name = dev_name(mtd->dev.parent);
+
+	/*
+	 * ->cmdfunc() is legacy and will only be used if ->exec_op() is not
+	 * populated.
+	 */
+	if (!chip->exec_op) {
+		/*
+		 * Default functions assigned for ->cmdfunc() and
+		 * ->select_chip() both expect ->cmd_ctrl() to be populated.
+		 */
+		if ((!chip->cmdfunc || !chip->select_chip) && !chip->cmd_ctrl) {
+			pr_err("->cmd_ctrl() should be provided\n");
+			return -EINVAL;
+		}
+	}
+
+	/* Set the default functions */
+	nand_set_defaults(chip);
+
+	/* Read the flash type */
+	ret = nand_detect(chip, table);
+	if (ret) {
+		if (!(chip->options & NAND_SCAN_SILENT_NODEV))
+			pr_warn("No NAND device found\n");
+		chip->select_chip(mtd, -1);
+		return ret;
+	}
+
+	nand_maf_id = chip->id.data[0];
+	nand_dev_id = chip->id.data[1];
+
+	chip->select_chip(mtd, -1);
+
+	/* Check for a chip array */
+	for (i = 1; i < maxchips; i++) {
+		u8 id[2];
+
+		/* See comment in nand_get_flash_type for reset */
+		nand_reset(chip, i);
+
+		chip->select_chip(mtd, i);
+		/* Send the command for reading device ID */
+		nand_readid_op(chip, 0, id, sizeof(id));
+		/* Read manufacturer and device IDs */
+		if (nand_maf_id != id[0] || nand_dev_id != id[1]) {
+			chip->select_chip(mtd, -1);
+			break;
+		}
+		chip->select_chip(mtd, -1);
+	}
+	if (i > 1)
+		pr_info("%d chips detected\n", i);
+
+	/* Store the number of chips and calc total size for mtd */
+	chip->numchips = i;
+	mtd->size = i * chip->chipsize;
+
+	return 0;
+}
+EXPORT_SYMBOL(nand_scan_ident);
+
+static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+
+	if (WARN_ON(ecc->mode != NAND_ECC_SOFT))
+		return -EINVAL;
+
+	switch (ecc->algo) {
+	case NAND_ECC_HAMMING:
+		ecc->calculate = nand_calculate_ecc;
+		ecc->correct = nand_correct_data;
+		ecc->read_page = nand_read_page_swecc;
+		ecc->read_subpage = nand_read_subpage;
+		ecc->write_page = nand_write_page_swecc;
+		ecc->read_page_raw = nand_read_page_raw;
+		ecc->write_page_raw = nand_write_page_raw;
+		ecc->read_oob = nand_read_oob_std;
+		ecc->write_oob = nand_write_oob_std;
+		if (!ecc->size)
+			ecc->size = 256;
+		ecc->bytes = 3;
+		ecc->strength = 1;
+		return 0;
+	case NAND_ECC_BCH:
+		if (!mtd_nand_has_bch()) {
+			WARN(1, "CONFIG_MTD_NAND_ECC_BCH not enabled\n");
+			return -EINVAL;
+		}
+		ecc->calculate = nand_bch_calculate_ecc;
+		ecc->correct = nand_bch_correct_data;
+		ecc->read_page = nand_read_page_swecc;
+		ecc->read_subpage = nand_read_subpage;
+		ecc->write_page = nand_write_page_swecc;
+		ecc->read_page_raw = nand_read_page_raw;
+		ecc->write_page_raw = nand_write_page_raw;
+		ecc->read_oob = nand_read_oob_std;
+		ecc->write_oob = nand_write_oob_std;
+
+		/*
+		* Board driver should supply ecc.size and ecc.strength
+		* values to select how many bits are correctable.
+		* Otherwise, default to 4 bits for large page devices.
+		*/
+		if (!ecc->size && (mtd->oobsize >= 64)) {
+			ecc->size = 512;
+			ecc->strength = 4;
+		}
+
+		/*
+		 * if no ecc placement scheme was provided pickup the default
+		 * large page one.
+		 */
+		if (!mtd->ooblayout) {
+			/* handle large page devices only */
+			if (mtd->oobsize < 64) {
+				WARN(1, "OOB layout is required when using software BCH on small pages\n");
+				return -EINVAL;
+			}
+
+			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_ops);
+
+		}
+
+		/*
+		 * We can only maximize ECC config when the default layout is
+		 * used, otherwise we don't know how many bytes can really be
+		 * used.
+		 */
+		if (mtd->ooblayout == &nand_ooblayout_lp_ops &&
+		    ecc->options & NAND_ECC_MAXIMIZE) {
+			int steps, bytes;
+
+			/* Always prefer 1k blocks over 512bytes ones */
+			ecc->size = 1024;
+			steps = mtd->writesize / ecc->size;
+
+			/* Reserve 2 bytes for the BBM */
+			bytes = (mtd->oobsize - 2) / steps;
+			ecc->strength = bytes * 8 / fls(8 * ecc->size);
+		}
+
+		/* See nand_bch_init() for details. */
+		ecc->bytes = 0;
+		ecc->priv = nand_bch_init(mtd);
+		if (!ecc->priv) {
+			WARN(1, "BCH ECC initialization failed!\n");
+			return -EINVAL;
+		}
+		return 0;
+	default:
+		WARN(1, "Unsupported ECC algorithm!\n");
+		return -EINVAL;
+	}
+}
+
+/**
+ * nand_check_ecc_caps - check the sanity of preset ECC settings
+ * @chip: nand chip info structure
+ * @caps: ECC caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * When ECC step size and strength are already set, check if they are supported
+ * by the controller and the calculated ECC bytes fit within the chip's OOB.
+ * On success, the calculated ECC bytes is set.
+ */
+int nand_check_ecc_caps(struct nand_chip *chip,
+			const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int preset_step = chip->ecc.size;
+	int preset_strength = chip->ecc.strength;
+	int nsteps, ecc_bytes;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	if (!preset_step || !preset_strength)
+		return -ENODATA;
+
+	nsteps = mtd->writesize / preset_step;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+
+		if (stepinfo->stepsize != preset_step)
+			continue;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			if (stepinfo->strengths[j] != preset_strength)
+				continue;
+
+			ecc_bytes = caps->calc_ecc_bytes(preset_step,
+							 preset_strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				return ecc_bytes;
+
+			if (ecc_bytes * nsteps > oobavail) {
+				pr_err("ECC (step, strength) = (%d, %d) does not fit in OOB",
+				       preset_step, preset_strength);
+				return -ENOSPC;
+			}
+
+			chip->ecc.bytes = ecc_bytes;
+
+			return 0;
+		}
+	}
+
+	pr_err("ECC (step, strength) = (%d, %d) not supported on this controller",
+	       preset_step, preset_strength);
+
+	return -ENOTSUPP;
+}
+EXPORT_SYMBOL_GPL(nand_check_ecc_caps);
+
+/**
+ * nand_match_ecc_req - meet the chip's requirement with least ECC bytes
+ * @chip: nand chip info structure
+ * @caps: ECC engine caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * If a chip's ECC requirement is provided, try to meet it with the least
+ * number of ECC bytes (i.e. with the largest number of OOB-free bytes).
+ * On success, the chosen ECC settings are set.
+ */
+int nand_match_ecc_req(struct nand_chip *chip,
+		       const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int req_step = chip->ecc_step_ds;
+	int req_strength = chip->ecc_strength_ds;
+	int req_corr, step_size, strength, nsteps, ecc_bytes, ecc_bytes_total;
+	int best_step, best_strength, best_ecc_bytes;
+	int best_ecc_bytes_total = INT_MAX;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	/* No information provided by the NAND chip */
+	if (!req_step || !req_strength)
+		return -ENOTSUPP;
+
+	/* number of correctable bits the chip requires in a page */
+	req_corr = mtd->writesize / req_step * req_strength;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+		step_size = stepinfo->stepsize;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			strength = stepinfo->strengths[j];
+
+			/*
+			 * If both step size and strength are smaller than the
+			 * chip's requirement, it is not easy to compare the
+			 * resulted reliability.
+			 */
+			if (step_size < req_step && strength < req_strength)
+				continue;
+
+			if (mtd->writesize % step_size)
+				continue;
+
+			nsteps = mtd->writesize / step_size;
+
+			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				continue;
+			ecc_bytes_total = ecc_bytes * nsteps;
+
+			if (ecc_bytes_total > oobavail ||
+			    strength * nsteps < req_corr)
+				continue;
+
+			/*
+			 * We assume the best is to meet the chip's requrement
+			 * with the least number of ECC bytes.
+			 */
+			if (ecc_bytes_total < best_ecc_bytes_total) {
+				best_ecc_bytes_total = ecc_bytes_total;
+				best_step = step_size;
+				best_strength = strength;
+				best_ecc_bytes = ecc_bytes;
+			}
+		}
+	}
+
+	if (best_ecc_bytes_total == INT_MAX)
+		return -ENOTSUPP;
+
+	chip->ecc.size = best_step;
+	chip->ecc.strength = best_strength;
+	chip->ecc.bytes = best_ecc_bytes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_match_ecc_req);
+
+/**
+ * nand_maximize_ecc - choose the max ECC strength available
+ * @chip: nand chip info structure
+ * @caps: ECC engine caps info structure
+ * @oobavail: OOB size that the ECC engine can use
+ *
+ * Choose the max ECC strength that is supported on the controller, and can fit
+ * within the chip's OOB.  On success, the chosen ECC settings are set.
+ */
+int nand_maximize_ecc(struct nand_chip *chip,
+		      const struct nand_ecc_caps *caps, int oobavail)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_ecc_step_info *stepinfo;
+	int step_size, strength, nsteps, ecc_bytes, corr;
+	int best_corr = 0;
+	int best_step = 0;
+	int best_strength, best_ecc_bytes;
+	int i, j;
+
+	if (WARN_ON(oobavail < 0))
+		return -EINVAL;
+
+	for (i = 0; i < caps->nstepinfos; i++) {
+		stepinfo = &caps->stepinfos[i];
+		step_size = stepinfo->stepsize;
+
+		/* If chip->ecc.size is already set, respect it */
+		if (chip->ecc.size && step_size != chip->ecc.size)
+			continue;
+
+		for (j = 0; j < stepinfo->nstrengths; j++) {
+			strength = stepinfo->strengths[j];
+
+			if (mtd->writesize % step_size)
+				continue;
+
+			nsteps = mtd->writesize / step_size;
+
+			ecc_bytes = caps->calc_ecc_bytes(step_size, strength);
+			if (WARN_ON_ONCE(ecc_bytes < 0))
+				continue;
+
+			if (ecc_bytes * nsteps > oobavail)
+				continue;
+
+			corr = strength * nsteps;
+
+			/*
+			 * If the number of correctable bits is the same,
+			 * bigger step_size has more reliability.
+			 */
+			if (corr > best_corr ||
+			    (corr == best_corr && step_size > best_step)) {
+				best_corr = corr;
+				best_step = step_size;
+				best_strength = strength;
+				best_ecc_bytes = ecc_bytes;
+			}
+		}
+	}
+
+	if (!best_corr)
+		return -ENOTSUPP;
+
+	chip->ecc.size = best_step;
+	chip->ecc.strength = best_strength;
+	chip->ecc.bytes = best_ecc_bytes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nand_maximize_ecc);
+
+/*
+ * Check if the chip configuration meet the datasheet requirements.
+
+ * If our configuration corrects A bits per B bytes and the minimum
+ * required correction level is X bits per Y bytes, then we must ensure
+ * both of the following are true:
+ *
+ * (1) A / B >= X / Y
+ * (2) A >= X
+ *
+ * Requirement (1) ensures we can correct for the required bitflip density.
+ * Requirement (2) ensures we can correct even when all bitflips are clumped
+ * in the same sector.
+ */
+static bool nand_ecc_strength_good(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int corr, ds_corr;
+
+	if (ecc->size == 0 || chip->ecc_step_ds == 0)
+		/* Not enough information */
+		return true;
+
+	/*
+	 * We get the number of corrected bits per page to compare
+	 * the correction density.
+	 */
+	corr = (mtd->writesize * ecc->strength) / ecc->size;
+	ds_corr = (mtd->writesize * chip->ecc_strength_ds) / chip->ecc_step_ds;
+
+	return corr >= ds_corr && ecc->strength >= chip->ecc_strength_ds;
+}
+
+/**
+ * nand_scan_tail - [NAND Interface] Scan for the NAND device
+ * @mtd: MTD device structure
+ *
+ * This is the second phase of the normal nand_scan() function. It fills out
+ * all the uninitialized function pointers with the defaults and scans for a
+ * bad block table if appropriate.
+ */
+int nand_scan_tail(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int ret, i;
+
+	/* New bad blocks should be marked in OOB, flash-based BBT, or both */
+	if (WARN_ON((chip->bbt_options & NAND_BBT_NO_OOB_BBM) &&
+		   !(chip->bbt_options & NAND_BBT_USE_FLASH))) {
+		return -EINVAL;
+	}
+
+	chip->data_buf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
+	if (!chip->data_buf)
+		return -ENOMEM;
+
+	/*
+	 * FIXME: some NAND manufacturer drivers expect the first die to be
+	 * selected when manufacturer->init() is called. They should be fixed
+	 * to explictly select the relevant die when interacting with the NAND
+	 * chip.
+	 */
+	chip->select_chip(mtd, 0);
+	ret = nand_manufacturer_init(chip);
+	chip->select_chip(mtd, -1);
+	if (ret)
+		goto err_free_buf;
+
+	/* Set the internal oob buffer location, just after the page data */
+	chip->oob_poi = chip->data_buf + mtd->writesize;
+
+	/*
+	 * If no default placement scheme is given, select an appropriate one.
+	 */
+	if (!mtd->ooblayout &&
+	    !(ecc->mode == NAND_ECC_SOFT && ecc->algo == NAND_ECC_BCH)) {
+		switch (mtd->oobsize) {
+		case 8:
+		case 16:
+			mtd_set_ooblayout(mtd, &nand_ooblayout_sp_ops);
+			break;
+		case 64:
+		case 128:
+			mtd_set_ooblayout(mtd, &nand_ooblayout_lp_hamming_ops);
+			break;
+		default:
+			/*
+			 * Expose the whole OOB area to users if ECC_NONE
+			 * is passed. We could do that for all kind of
+			 * ->oobsize, but we must keep the old large/small
+			 * page with ECC layout when ->oobsize <= 128 for
+			 * compatibility reasons.
+			 */
+			if (ecc->mode == NAND_ECC_NONE) {
+				mtd_set_ooblayout(mtd,
+						&nand_ooblayout_lp_ops);
+				break;
+			}
+
+			WARN(1, "No oob scheme defined for oobsize %d\n",
+				mtd->oobsize);
+			ret = -EINVAL;
+			goto err_nand_manuf_cleanup;
+		}
+	}
+
+	/*
+	 * Check ECC mode, default to software if 3byte/512byte hardware ECC is
+	 * selected and we have 256 byte pagesize fallback to software ECC
+	 */
+
+	switch (ecc->mode) {
+	case NAND_ECC_HW_OOB_FIRST:
+		/* Similar to NAND_ECC_HW, but a separate read_page handle */
+		if (!ecc->calculate || !ecc->correct || !ecc->hwctl) {
+			WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
+			ret = -EINVAL;
+			goto err_nand_manuf_cleanup;
+		}
+		if (!ecc->read_page)
+			ecc->read_page = nand_read_page_hwecc_oob_first;
+
+	case NAND_ECC_HW:
+		/* Use standard hwecc read page function? */
+		if (!ecc->read_page)
+			ecc->read_page = nand_read_page_hwecc;
+		if (!ecc->write_page)
+			ecc->write_page = nand_write_page_hwecc;
+		if (!ecc->read_page_raw)
+			ecc->read_page_raw = nand_read_page_raw;
+		if (!ecc->write_page_raw)
+			ecc->write_page_raw = nand_write_page_raw;
+		if (!ecc->read_oob)
+			ecc->read_oob = nand_read_oob_std;
+		if (!ecc->write_oob)
+			ecc->write_oob = nand_write_oob_std;
+		if (!ecc->read_subpage)
+			ecc->read_subpage = nand_read_subpage;
+		if (!ecc->write_subpage && ecc->hwctl && ecc->calculate)
+			ecc->write_subpage = nand_write_subpage_hwecc;
+
+	case NAND_ECC_HW_SYNDROME:
+		if ((!ecc->calculate || !ecc->correct || !ecc->hwctl) &&
+		    (!ecc->read_page ||
+		     ecc->read_page == nand_read_page_hwecc ||
+		     !ecc->write_page ||
+		     ecc->write_page == nand_write_page_hwecc)) {
+			WARN(1, "No ECC functions supplied; hardware ECC not possible\n");
+			ret = -EINVAL;
+			goto err_nand_manuf_cleanup;
+		}
+		/* Use standard syndrome read/write page function? */
+		if (!ecc->read_page)
+			ecc->read_page = nand_read_page_syndrome;
+		if (!ecc->write_page)
+			ecc->write_page = nand_write_page_syndrome;
+		if (!ecc->read_page_raw)
+			ecc->read_page_raw = nand_read_page_raw_syndrome;
+		if (!ecc->write_page_raw)
+			ecc->write_page_raw = nand_write_page_raw_syndrome;
+		if (!ecc->read_oob)
+			ecc->read_oob = nand_read_oob_syndrome;
+		if (!ecc->write_oob)
+			ecc->write_oob = nand_write_oob_syndrome;
+
+		if (mtd->writesize >= ecc->size) {
+			if (!ecc->strength) {
+				WARN(1, "Driver must set ecc.strength when using hardware ECC\n");
+				ret = -EINVAL;
+				goto err_nand_manuf_cleanup;
+			}
+			break;
+		}
+		pr_warn("%d byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
+			ecc->size, mtd->writesize);
+		ecc->mode = NAND_ECC_SOFT;
+		ecc->algo = NAND_ECC_HAMMING;
+
+	case NAND_ECC_SOFT:
+		ret = nand_set_ecc_soft_ops(mtd);
+		if (ret) {
+			ret = -EINVAL;
+			goto err_nand_manuf_cleanup;
+		}
+		break;
+
+	case NAND_ECC_ON_DIE:
+		if (!ecc->read_page || !ecc->write_page) {
+			WARN(1, "No ECC functions supplied; on-die ECC not possible\n");
+			ret = -EINVAL;
+			goto err_nand_manuf_cleanup;
+		}
+		if (!ecc->read_oob)
+			ecc->read_oob = nand_read_oob_std;
+		if (!ecc->write_oob)
+			ecc->write_oob = nand_write_oob_std;
+		break;
+
+	case NAND_ECC_NONE:
+		pr_warn("NAND_ECC_NONE selected by board driver. This is not recommended!\n");
+		ecc->read_page = nand_read_page_raw;
+		ecc->write_page = nand_write_page_raw;
+		ecc->read_oob = nand_read_oob_std;
+		ecc->read_page_raw = nand_read_page_raw;
+		ecc->write_page_raw = nand_write_page_raw;
+		ecc->write_oob = nand_write_oob_std;
+		ecc->size = mtd->writesize;
+		ecc->bytes = 0;
+		ecc->strength = 0;
+		break;
+
+	default:
+		WARN(1, "Invalid NAND_ECC_MODE %d\n", ecc->mode);
+		ret = -EINVAL;
+		goto err_nand_manuf_cleanup;
+	}
+
+	if (ecc->correct || ecc->calculate) {
+		ecc->calc_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
+		ecc->code_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
+		if (!ecc->calc_buf || !ecc->code_buf) {
+			ret = -ENOMEM;
+			goto err_nand_manuf_cleanup;
+		}
+	}
+
+	/* For many systems, the standard OOB write also works for raw */
+	if (!ecc->read_oob_raw)
+		ecc->read_oob_raw = ecc->read_oob;
+	if (!ecc->write_oob_raw)
+		ecc->write_oob_raw = ecc->write_oob;
+
+	/* propagate ecc info to mtd_info */
+	mtd->ecc_strength = ecc->strength;
+	mtd->ecc_step_size = ecc->size;
+
+	/*
+	 * Set the number of read / write steps for one page depending on ECC
+	 * mode.
+	 */
+	ecc->steps = mtd->writesize / ecc->size;
+	if (ecc->steps * ecc->size != mtd->writesize) {
+		WARN(1, "Invalid ECC parameters\n");
+		ret = -EINVAL;
+		goto err_nand_manuf_cleanup;
+	}
+	ecc->total = ecc->steps * ecc->bytes;
+	if (ecc->total > mtd->oobsize) {
+		WARN(1, "Total number of ECC bytes exceeded oobsize\n");
+		ret = -EINVAL;
+		goto err_nand_manuf_cleanup;
+	}
+
+	/*
+	 * The number of bytes available for a client to place data into
+	 * the out of band area.
+	 */
+	ret = mtd_ooblayout_count_freebytes(mtd);
+	if (ret < 0)
+		ret = 0;
+
+	mtd->oobavail = ret;
+
+	/* ECC sanity check: warn if it's too weak */
+	if (!nand_ecc_strength_good(mtd))
+		pr_warn("WARNING: %s: the ECC used on your system is too weak compared to the one required by the NAND chip\n",
+			mtd->name);
+
+	/* Allow subpage writes up to ecc.steps. Not possible for MLC flash */
+	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) && nand_is_slc(chip)) {
+		switch (ecc->steps) {
+		case 2:
+			mtd->subpage_sft = 1;
+			break;
+		case 4:
+		case 8:
+		case 16:
+			mtd->subpage_sft = 2;
+			break;
+		}
+	}
+	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;
+
+	/* Initialize state */
+	chip->state = FL_READY;
+
+	/* Invalidate the pagebuffer reference */
+	chip->pagebuf = -1;
+
+	/* Large page NAND with SOFT_ECC should support subpage reads */
+	switch (ecc->mode) {
+	case NAND_ECC_SOFT:
+		if (chip->page_shift > 9)
+			chip->options |= NAND_SUBPAGE_READ;
+		break;
+
+	default:
+		break;
+	}
+
+	/* Fill in remaining MTD driver data */
+	mtd->type = nand_is_slc(chip) ? MTD_NANDFLASH : MTD_MLCNANDFLASH;
+	mtd->flags = (chip->options & NAND_ROM) ? MTD_CAP_ROM :
+						MTD_CAP_NANDFLASH;
+	mtd->_erase = nand_erase;
+	mtd->_point = NULL;
+	mtd->_unpoint = NULL;
+	mtd->_panic_write = panic_nand_write;
+	mtd->_read_oob = nand_read_oob;
+	mtd->_write_oob = nand_write_oob;
+	mtd->_sync = nand_sync;
+	mtd->_lock = NULL;
+	mtd->_unlock = NULL;
+	mtd->_suspend = nand_suspend;
+	mtd->_resume = nand_resume;
+	mtd->_reboot = nand_shutdown;
+	mtd->_block_isreserved = nand_block_isreserved;
+	mtd->_block_isbad = nand_block_isbad;
+	mtd->_block_markbad = nand_block_markbad;
+	mtd->_max_bad_blocks = nand_max_bad_blocks;
+	mtd->writebufsize = mtd->writesize;
+
+	/*
+	 * Initialize bitflip_threshold to its default prior scan_bbt() call.
+	 * scan_bbt() might invoke mtd_read(), thus bitflip_threshold must be
+	 * properly set.
+	 */
+	if (!mtd->bitflip_threshold)
+		mtd->bitflip_threshold = DIV_ROUND_UP(mtd->ecc_strength * 3, 4);
+
+	/* Initialize the ->data_interface field. */
+	ret = nand_init_data_interface(chip);
+	if (ret)
+		goto err_nand_manuf_cleanup;
+
+	/* Enter fastest possible mode on all dies. */
+	for (i = 0; i < chip->numchips; i++) {
+		ret = nand_setup_data_interface(chip, i);
+		if (ret)
+			goto err_nand_manuf_cleanup;
+	}
+
+	/* Check, if we should skip the bad block table scan */
+	if (chip->options & NAND_SKIP_BBTSCAN)
+		return 0;
+
+	/* Build bad block table */
+	ret = chip->scan_bbt(mtd);
+	if (ret)
+		goto err_nand_manuf_cleanup;
+
+	return 0;
+
+
+err_nand_manuf_cleanup:
+	nand_manufacturer_cleanup(chip);
+
+err_free_buf:
+	kfree(chip->data_buf);
+	kfree(ecc->code_buf);
+	kfree(ecc->calc_buf);
+
+	return ret;
+}
+EXPORT_SYMBOL(nand_scan_tail);
+
+/*
+ * is_module_text_address() isn't exported, and it's mostly a pointless
+ * test if this is a module _anyway_ -- they'd have to try _really_ hard
+ * to call us from in-kernel code if the core NAND support is modular.
+ */
+#ifdef MODULE
+#define caller_is_module() (1)
+#else
+#define caller_is_module() \
+	is_module_text_address((unsigned long)__builtin_return_address(0))
+#endif
+
+/**
+ * nand_scan - [NAND Interface] Scan for the NAND device
+ * @mtd: MTD device structure
+ * @maxchips: number of chips to scan for
+ *
+ * This fills out all the uninitialized function pointers with the defaults.
+ * The flash ID is read and the mtd/chip structures are filled with the
+ * appropriate values.
+ */
+int nand_scan(struct mtd_info *mtd, int maxchips)
+{
+	int ret;
+
+	ret = nand_scan_ident(mtd, maxchips, NULL);
+	if (!ret)
+		ret = nand_scan_tail(mtd);
+	return ret;
+}
+EXPORT_SYMBOL(nand_scan);
+
+/**
+ * nand_cleanup - [NAND Interface] Free resources held by the NAND device
+ * @chip: NAND chip object
+ */
+void nand_cleanup(struct nand_chip *chip)
+{
+	if (chip->ecc.mode == NAND_ECC_SOFT &&
+	    chip->ecc.algo == NAND_ECC_BCH)
+		nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
+
+	/* Free bad block table memory */
+	kfree(chip->bbt);
+	kfree(chip->data_buf);
+	kfree(chip->ecc.code_buf);
+	kfree(chip->ecc.calc_buf);
+
+	/* Free bad block descriptor memory */
+	if (chip->badblock_pattern && chip->badblock_pattern->options
+			& NAND_BBT_DYNAMICSTRUCT)
+		kfree(chip->badblock_pattern);
+
+	/* Free manufacturer priv data. */
+	nand_manufacturer_cleanup(chip);
+}
+EXPORT_SYMBOL_GPL(nand_cleanup);
+
+/**
+ * nand_release - [NAND Interface] Unregister the MTD device and free resources
+ *		  held by the NAND device
+ * @mtd: MTD device structure
+ */
+void nand_release(struct mtd_info *mtd)
+{
+	mtd_device_unregister(mtd);
+	nand_cleanup(mtd_to_nand(mtd));
+}
+EXPORT_SYMBOL_GPL(nand_release);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Steven J. Hill <sjhill@realitydiluted.com>");
+MODULE_AUTHOR("Thomas Gleixner <tglx@linutronix.de>");
+MODULE_DESCRIPTION("Generic NAND flash driver code");