Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 2667 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
new file mode 100644
index 000000000..200d3ab34
--- /dev/null
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -0,0 +1,2667 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Freescale GPMI NAND Flash Driver
+ *
+ * Copyright (C) 2010-2015 Freescale Semiconductor, Inc.
+ * Copyright (C) 2008 Embedded Alley Solutions, Inc.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/sched/task_stack.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/dma/mxs-dma.h>
+#include "gpmi-nand.h"
+#include "gpmi-regs.h"
+#include "bch-regs.h"
+
+/* Resource names for the GPMI NAND driver. */
+#define GPMI_NAND_GPMI_REGS_ADDR_RES_NAME  "gpmi-nand"
+#define GPMI_NAND_BCH_REGS_ADDR_RES_NAME   "bch"
+#define GPMI_NAND_BCH_INTERRUPT_RES_NAME   "bch"
+
+/* Converts time to clock cycles */
+#define TO_CYCLES(duration, period) DIV_ROUND_UP_ULL(duration, period)
+
+#define MXS_SET_ADDR		0x4
+#define MXS_CLR_ADDR		0x8
+/*
+ * Clear the bit and poll it cleared.  This is usually called with
+ * a reset address and mask being either SFTRST(bit 31) or CLKGATE
+ * (bit 30).
+ */
+static int clear_poll_bit(void __iomem *addr, u32 mask)
+{
+	int timeout = 0x400;
+
+	/* clear the bit */
+	writel(mask, addr + MXS_CLR_ADDR);
+
+	/*
+	 * SFTRST needs 3 GPMI clocks to settle, the reference manual
+	 * recommends to wait 1us.
+	 */
+	udelay(1);
+
+	/* poll the bit becoming clear */
+	while ((readl(addr) & mask) && --timeout)
+		/* nothing */;
+
+	return !timeout;
+}
+
+#define MODULE_CLKGATE		(1 << 30)
+#define MODULE_SFTRST		(1 << 31)
+/*
+ * The current mxs_reset_block() will do two things:
+ *  [1] enable the module.
+ *  [2] reset the module.
+ *
+ * In most of the cases, it's ok.
+ * But in MX23, there is a hardware bug in the BCH block (see erratum #2847).
+ * If you try to soft reset the BCH block, it becomes unusable until
+ * the next hard reset. This case occurs in the NAND boot mode. When the board
+ * boots by NAND, the ROM of the chip will initialize the BCH blocks itself.
+ * So If the driver tries to reset the BCH again, the BCH will not work anymore.
+ * You will see a DMA timeout in this case. The bug has been fixed
+ * in the following chips, such as MX28.
+ *
+ * To avoid this bug, just add a new parameter `just_enable` for
+ * the mxs_reset_block(), and rewrite it here.
+ */
+static int gpmi_reset_block(void __iomem *reset_addr, bool just_enable)
+{
+	int ret;
+	int timeout = 0x400;
+
+	/* clear and poll SFTRST */
+	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
+	if (unlikely(ret))
+		goto error;
+
+	/* clear CLKGATE */
+	writel(MODULE_CLKGATE, reset_addr + MXS_CLR_ADDR);
+
+	if (!just_enable) {
+		/* set SFTRST to reset the block */
+		writel(MODULE_SFTRST, reset_addr + MXS_SET_ADDR);
+		udelay(1);
+
+		/* poll CLKGATE becoming set */
+		while ((!(readl(reset_addr) & MODULE_CLKGATE)) && --timeout)
+			/* nothing */;
+		if (unlikely(!timeout))
+			goto error;
+	}
+
+	/* clear and poll SFTRST */
+	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
+	if (unlikely(ret))
+		goto error;
+
+	/* clear and poll CLKGATE */
+	ret = clear_poll_bit(reset_addr, MODULE_CLKGATE);
+	if (unlikely(ret))
+		goto error;
+
+	return 0;
+
+error:
+	pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
+	return -ETIMEDOUT;
+}
+
+static int __gpmi_enable_clk(struct gpmi_nand_data *this, bool v)
+{
+	struct clk *clk;
+	int ret;
+	int i;
+
+	for (i = 0; i < GPMI_CLK_MAX; i++) {
+		clk = this->resources.clock[i];
+		if (!clk)
+			break;
+
+		if (v) {
+			ret = clk_prepare_enable(clk);
+			if (ret)
+				goto err_clk;
+		} else {
+			clk_disable_unprepare(clk);
+		}
+	}
+	return 0;
+
+err_clk:
+	for (; i > 0; i--)
+		clk_disable_unprepare(this->resources.clock[i - 1]);
+	return ret;
+}
+
+static int gpmi_init(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	int ret;
+
+	ret = pm_runtime_get_sync(this->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(this->dev);
+		return ret;
+	}
+
+	ret = gpmi_reset_block(r->gpmi_regs, false);
+	if (ret)
+		goto err_out;
+
+	/*
+	 * Reset BCH here, too. We got failures otherwise :(
+	 * See later BCH reset for explanation of MX23 and MX28 handling
+	 */
+	ret = gpmi_reset_block(r->bch_regs, GPMI_IS_MXS(this));
+	if (ret)
+		goto err_out;
+
+	/* Choose NAND mode. */
+	writel(BM_GPMI_CTRL1_GPMI_MODE, r->gpmi_regs + HW_GPMI_CTRL1_CLR);
+
+	/* Set the IRQ polarity. */
+	writel(BM_GPMI_CTRL1_ATA_IRQRDY_POLARITY,
+				r->gpmi_regs + HW_GPMI_CTRL1_SET);
+
+	/* Disable Write-Protection. */
+	writel(BM_GPMI_CTRL1_DEV_RESET, r->gpmi_regs + HW_GPMI_CTRL1_SET);
+
+	/* Select BCH ECC. */
+	writel(BM_GPMI_CTRL1_BCH_MODE, r->gpmi_regs + HW_GPMI_CTRL1_SET);
+
+	/*
+	 * Decouple the chip select from dma channel. We use dma0 for all
+	 * the chips.
+	 */
+	writel(BM_GPMI_CTRL1_DECOUPLE_CS, r->gpmi_regs + HW_GPMI_CTRL1_SET);
+
+err_out:
+	pm_runtime_mark_last_busy(this->dev);
+	pm_runtime_put_autosuspend(this->dev);
+	return ret;
+}
+
+/* This function is very useful. It is called only when the bug occur. */
+static void gpmi_dump_info(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	struct bch_geometry *geo = &this->bch_geometry;
+	u32 reg;
+	int i;
+
+	dev_err(this->dev, "Show GPMI registers :\n");
+	for (i = 0; i <= HW_GPMI_DEBUG / 0x10 + 1; i++) {
+		reg = readl(r->gpmi_regs + i * 0x10);
+		dev_err(this->dev, "offset 0x%.3x : 0x%.8x\n", i * 0x10, reg);
+	}
+
+	/* start to print out the BCH info */
+	dev_err(this->dev, "Show BCH registers :\n");
+	for (i = 0; i <= HW_BCH_VERSION / 0x10 + 1; i++) {
+		reg = readl(r->bch_regs + i * 0x10);
+		dev_err(this->dev, "offset 0x%.3x : 0x%.8x\n", i * 0x10, reg);
+	}
+	dev_err(this->dev, "BCH Geometry :\n"
+		"GF length              : %u\n"
+		"ECC Strength           : %u\n"
+		"Page Size in Bytes     : %u\n"
+		"Metadata Size in Bytes : %u\n"
+		"ECC Chunk Size in Bytes: %u\n"
+		"ECC Chunk Count        : %u\n"
+		"Payload Size in Bytes  : %u\n"
+		"Auxiliary Size in Bytes: %u\n"
+		"Auxiliary Status Offset: %u\n"
+		"Block Mark Byte Offset : %u\n"
+		"Block Mark Bit Offset  : %u\n",
+		geo->gf_len,
+		geo->ecc_strength,
+		geo->page_size,
+		geo->metadata_size,
+		geo->ecc_chunk_size,
+		geo->ecc_chunk_count,
+		geo->payload_size,
+		geo->auxiliary_size,
+		geo->auxiliary_status_offset,
+		geo->block_mark_byte_offset,
+		geo->block_mark_bit_offset);
+}
+
+static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+
+	/* Do the sanity check. */
+	if (GPMI_IS_MXS(this)) {
+		/* The mx23/mx28 only support the GF13. */
+		if (geo->gf_len == 14)
+			return false;
+	}
+	return geo->ecc_strength <= this->devdata->bch_max_ecc_strength;
+}
+
+/*
+ * If we can get the ECC information from the nand chip, we do not
+ * need to calculate them ourselves.
+ *
+ * We may have available oob space in this case.
+ */
+static int set_geometry_by_ecc_info(struct gpmi_nand_data *this,
+				    unsigned int ecc_strength,
+				    unsigned int ecc_step)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int block_mark_bit_offset;
+
+	switch (ecc_step) {
+	case SZ_512:
+		geo->gf_len = 13;
+		break;
+	case SZ_1K:
+		geo->gf_len = 14;
+		break;
+	default:
+		dev_err(this->dev,
+			"unsupported nand chip. ecc bits : %d, ecc size : %d\n",
+			nanddev_get_ecc_requirements(&chip->base)->strength,
+			nanddev_get_ecc_requirements(&chip->base)->step_size);
+		return -EINVAL;
+	}
+	geo->ecc_chunk_size = ecc_step;
+	geo->ecc_strength = round_up(ecc_strength, 2);
+	if (!gpmi_check_ecc(this))
+		return -EINVAL;
+
+	/* Keep the C >= O */
+	if (geo->ecc_chunk_size < mtd->oobsize) {
+		dev_err(this->dev,
+			"unsupported nand chip. ecc size: %d, oob size : %d\n",
+			ecc_step, mtd->oobsize);
+		return -EINVAL;
+	}
+
+	/* The default value, see comment in the legacy_set_geometry(). */
+	geo->metadata_size = 10;
+
+	geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
+
+	/*
+	 * Now, the NAND chip with 2K page(data chunk is 512byte) shows below:
+	 *
+	 *    |                          P                            |
+	 *    |<----------------------------------------------------->|
+	 *    |                                                       |
+	 *    |                                        (Block Mark)   |
+	 *    |                      P'                      |      | |     |
+	 *    |<-------------------------------------------->|  D   | |  O' |
+	 *    |                                              |<---->| |<--->|
+	 *    V                                              V      V V     V
+	 *    +---+----------+-+----------+-+----------+-+----------+-+-----+
+	 *    | M |   data   |E|   data   |E|   data   |E|   data   |E|     |
+	 *    +---+----------+-+----------+-+----------+-+----------+-+-----+
+	 *                                                   ^              ^
+	 *                                                   |      O       |
+	 *                                                   |<------------>|
+	 *                                                   |              |
+	 *
+	 *	P : the page size for BCH module.
+	 *	E : The ECC strength.
+	 *	G : the length of Galois Field.
+	 *	N : The chunk count of per page.
+	 *	M : the metasize of per page.
+	 *	C : the ecc chunk size, aka the "data" above.
+	 *	P': the nand chip's page size.
+	 *	O : the nand chip's oob size.
+	 *	O': the free oob.
+	 *
+	 *	The formula for P is :
+	 *
+	 *	            E * G * N
+	 *	       P = ------------ + P' + M
+	 *                      8
+	 *
+	 * The position of block mark moves forward in the ECC-based view
+	 * of page, and the delta is:
+	 *
+	 *                   E * G * (N - 1)
+	 *             D = (---------------- + M)
+	 *                          8
+	 *
+	 * Please see the comment in legacy_set_geometry().
+	 * With the condition C >= O , we still can get same result.
+	 * So the bit position of the physical block mark within the ECC-based
+	 * view of the page is :
+	 *             (P' - D) * 8
+	 */
+	geo->page_size = mtd->writesize + geo->metadata_size +
+		(geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
+
+	geo->payload_size = mtd->writesize;
+
+	geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4);
+	geo->auxiliary_size = ALIGN(geo->metadata_size, 4)
+				+ ALIGN(geo->ecc_chunk_count, 4);
+
+	if (!this->swap_block_mark)
+		return 0;
+
+	/* For bit swap. */
+	block_mark_bit_offset = mtd->writesize * 8 -
+		(geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
+				+ geo->metadata_size * 8);
+
+	geo->block_mark_byte_offset = block_mark_bit_offset / 8;
+	geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
+	return 0;
+}
+
+/*
+ *  Calculate the ECC strength by hand:
+ *	E : The ECC strength.
+ *	G : the length of Galois Field.
+ *	N : The chunk count of per page.
+ *	O : the oobsize of the NAND chip.
+ *	M : the metasize of per page.
+ *
+ *	The formula is :
+ *		E * G * N
+ *	      ------------ <= (O - M)
+ *                  8
+ *
+ *      So, we get E by:
+ *                    (O - M) * 8
+ *              E <= -------------
+ *                       G * N
+ */
+static inline int get_ecc_strength(struct gpmi_nand_data *this)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	struct mtd_info	*mtd = nand_to_mtd(&this->nand);
+	int ecc_strength;
+
+	ecc_strength = ((mtd->oobsize - geo->metadata_size) * 8)
+			/ (geo->gf_len * geo->ecc_chunk_count);
+
+	/* We need the minor even number. */
+	return round_down(ecc_strength, 2);
+}
+
+static int legacy_set_geometry(struct gpmi_nand_data *this)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	struct mtd_info *mtd = nand_to_mtd(&this->nand);
+	unsigned int metadata_size;
+	unsigned int status_size;
+	unsigned int block_mark_bit_offset;
+
+	/*
+	 * The size of the metadata can be changed, though we set it to 10
+	 * bytes now. But it can't be too large, because we have to save
+	 * enough space for BCH.
+	 */
+	geo->metadata_size = 10;
+
+	/* The default for the length of Galois Field. */
+	geo->gf_len = 13;
+
+	/* The default for chunk size. */
+	geo->ecc_chunk_size = 512;
+	while (geo->ecc_chunk_size < mtd->oobsize) {
+		geo->ecc_chunk_size *= 2; /* keep C >= O */
+		geo->gf_len = 14;
+	}
+
+	geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
+
+	/* We use the same ECC strength for all chunks. */
+	geo->ecc_strength = get_ecc_strength(this);
+	if (!gpmi_check_ecc(this)) {
+		dev_err(this->dev,
+			"ecc strength: %d cannot be supported by the controller (%d)\n"
+			"try to use minimum ecc strength that NAND chip required\n",
+			geo->ecc_strength,
+			this->devdata->bch_max_ecc_strength);
+		return -EINVAL;
+	}
+
+	geo->page_size = mtd->writesize + geo->metadata_size +
+		(geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
+	geo->payload_size = mtd->writesize;
+
+	/*
+	 * The auxiliary buffer contains the metadata and the ECC status. The
+	 * metadata is padded to the nearest 32-bit boundary. The ECC status
+	 * contains one byte for every ECC chunk, and is also padded to the
+	 * nearest 32-bit boundary.
+	 */
+	metadata_size = ALIGN(geo->metadata_size, 4);
+	status_size   = ALIGN(geo->ecc_chunk_count, 4);
+
+	geo->auxiliary_size = metadata_size + status_size;
+	geo->auxiliary_status_offset = metadata_size;
+
+	if (!this->swap_block_mark)
+		return 0;
+
+	/*
+	 * We need to compute the byte and bit offsets of
+	 * the physical block mark within the ECC-based view of the page.
+	 *
+	 * NAND chip with 2K page shows below:
+	 *                                             (Block Mark)
+	 *                                                   |      |
+	 *                                                   |  D   |
+	 *                                                   |<---->|
+	 *                                                   V      V
+	 *    +---+----------+-+----------+-+----------+-+----------+-+
+	 *    | M |   data   |E|   data   |E|   data   |E|   data   |E|
+	 *    +---+----------+-+----------+-+----------+-+----------+-+
+	 *
+	 * The position of block mark moves forward in the ECC-based view
+	 * of page, and the delta is:
+	 *
+	 *                   E * G * (N - 1)
+	 *             D = (---------------- + M)
+	 *                          8
+	 *
+	 * With the formula to compute the ECC strength, and the condition
+	 *       : C >= O         (C is the ecc chunk size)
+	 *
+	 * It's easy to deduce to the following result:
+	 *
+	 *         E * G       (O - M)      C - M         C - M
+	 *      ----------- <= ------- <=  --------  <  ---------
+	 *           8            N           N          (N - 1)
+	 *
+	 *  So, we get:
+	 *
+	 *                   E * G * (N - 1)
+	 *             D = (---------------- + M) < C
+	 *                          8
+	 *
+	 *  The above inequality means the position of block mark
+	 *  within the ECC-based view of the page is still in the data chunk,
+	 *  and it's NOT in the ECC bits of the chunk.
+	 *
+	 *  Use the following to compute the bit position of the
+	 *  physical block mark within the ECC-based view of the page:
+	 *          (page_size - D) * 8
+	 *
+	 *  --Huang Shijie
+	 */
+	block_mark_bit_offset = mtd->writesize * 8 -
+		(geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
+				+ geo->metadata_size * 8);
+
+	geo->block_mark_byte_offset = block_mark_bit_offset / 8;
+	geo->block_mark_bit_offset  = block_mark_bit_offset % 8;
+	return 0;
+}
+
+static int common_nfc_set_geometry(struct gpmi_nand_data *this)
+{
+	struct nand_chip *chip = &this->nand;
+	const struct nand_ecc_props *requirements =
+		nanddev_get_ecc_requirements(&chip->base);
+
+	if (chip->ecc.strength > 0 && chip->ecc.size > 0)
+		return set_geometry_by_ecc_info(this, chip->ecc.strength,
+						chip->ecc.size);
+
+	if ((of_property_read_bool(this->dev->of_node, "fsl,use-minimum-ecc"))
+				|| legacy_set_geometry(this)) {
+		if (!(requirements->strength > 0 && requirements->step_size > 0))
+			return -EINVAL;
+
+		return set_geometry_by_ecc_info(this,
+						requirements->strength,
+						requirements->step_size);
+	}
+
+	return 0;
+}
+
+/* Configures the geometry for BCH.  */
+static int bch_set_geometry(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	int ret;
+
+	ret = common_nfc_set_geometry(this);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_get_sync(this->dev);
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(this->dev);
+		return ret;
+	}
+
+	/*
+	* Due to erratum #2847 of the MX23, the BCH cannot be soft reset on this
+	* chip, otherwise it will lock up. So we skip resetting BCH on the MX23.
+	* and MX28.
+	*/
+	ret = gpmi_reset_block(r->bch_regs, GPMI_IS_MXS(this));
+	if (ret)
+		goto err_out;
+
+	/* Set *all* chip selects to use layout 0. */
+	writel(0, r->bch_regs + HW_BCH_LAYOUTSELECT);
+
+	ret = 0;
+err_out:
+	pm_runtime_mark_last_busy(this->dev);
+	pm_runtime_put_autosuspend(this->dev);
+
+	return ret;
+}
+
+/*
+ * <1> Firstly, we should know what's the GPMI-clock means.
+ *     The GPMI-clock is the internal clock in the gpmi nand controller.
+ *     If you set 100MHz to gpmi nand controller, the GPMI-clock's period
+ *     is 10ns. Mark the GPMI-clock's period as GPMI-clock-period.
+ *
+ * <2> Secondly, we should know what's the frequency on the nand chip pins.
+ *     The frequency on the nand chip pins is derived from the GPMI-clock.
+ *     We can get it from the following equation:
+ *
+ *         F = G / (DS + DH)
+ *
+ *         F  : the frequency on the nand chip pins.
+ *         G  : the GPMI clock, such as 100MHz.
+ *         DS : GPMI_HW_GPMI_TIMING0:DATA_SETUP
+ *         DH : GPMI_HW_GPMI_TIMING0:DATA_HOLD
+ *
+ * <3> Thirdly, when the frequency on the nand chip pins is above 33MHz,
+ *     the nand EDO(extended Data Out) timing could be applied.
+ *     The GPMI implements a feedback read strobe to sample the read data.
+ *     The feedback read strobe can be delayed to support the nand EDO timing
+ *     where the read strobe may deasserts before the read data is valid, and
+ *     read data is valid for some time after read strobe.
+ *
+ *     The following figure illustrates some aspects of a NAND Flash read:
+ *
+ *                   |<---tREA---->|
+ *                   |             |
+ *                   |         |   |
+ *                   |<--tRP-->|   |
+ *                   |         |   |
+ *                  __          ___|__________________________________
+ *     RDN            \________/   |
+ *                                 |
+ *                                 /---------\
+ *     Read Data    --------------<           >---------
+ *                                 \---------/
+ *                                |     |
+ *                                |<-D->|
+ *     FeedbackRDN  ________             ____________
+ *                          \___________/
+ *
+ *          D stands for delay, set in the HW_GPMI_CTRL1:RDN_DELAY.
+ *
+ *
+ * <4> Now, we begin to describe how to compute the right RDN_DELAY.
+ *
+ *  4.1) From the aspect of the nand chip pins:
+ *        Delay = (tREA + C - tRP)               {1}
+ *
+ *        tREA : the maximum read access time.
+ *        C    : a constant to adjust the delay. default is 4000ps.
+ *        tRP  : the read pulse width, which is exactly:
+ *                   tRP = (GPMI-clock-period) * DATA_SETUP
+ *
+ *  4.2) From the aspect of the GPMI nand controller:
+ *         Delay = RDN_DELAY * 0.125 * RP        {2}
+ *
+ *         RP   : the DLL reference period.
+ *            if (GPMI-clock-period > DLL_THRETHOLD)
+ *                   RP = GPMI-clock-period / 2;
+ *            else
+ *                   RP = GPMI-clock-period;
+ *
+ *            Set the HW_GPMI_CTRL1:HALF_PERIOD if GPMI-clock-period
+ *            is greater DLL_THRETHOLD. In other SOCs, the DLL_THRETHOLD
+ *            is 16000ps, but in mx6q, we use 12000ps.
+ *
+ *  4.3) since {1} equals {2}, we get:
+ *
+ *                     (tREA + 4000 - tRP) * 8
+ *         RDN_DELAY = -----------------------     {3}
+ *                           RP
+ */
+static void gpmi_nfc_compute_timings(struct gpmi_nand_data *this,
+				     const struct nand_sdr_timings *sdr)
+{
+	struct gpmi_nfc_hardware_timing *hw = &this->hw;
+	struct resources *r = &this->resources;
+	unsigned int dll_threshold_ps = this->devdata->max_chain_delay;
+	unsigned int period_ps, reference_period_ps;
+	unsigned int data_setup_cycles, data_hold_cycles, addr_setup_cycles;
+	unsigned int tRP_ps;
+	bool use_half_period;
+	int sample_delay_ps, sample_delay_factor;
+	unsigned int busy_timeout_cycles;
+	u8 wrn_dly_sel;
+	u64 busy_timeout_ps;
+
+	if (sdr->tRC_min >= 30000) {
+		/* ONFI non-EDO modes [0-3] */
+		hw->clk_rate = 22000000;
+		wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_4_TO_8NS;
+	} else if (sdr->tRC_min >= 25000) {
+		/* ONFI EDO mode 4 */
+		hw->clk_rate = 80000000;
+		wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY;
+	} else {
+		/* ONFI EDO mode 5 */
+		hw->clk_rate = 100000000;
+		wrn_dly_sel = BV_GPMI_CTRL1_WRN_DLY_SEL_NO_DELAY;
+	}
+
+	hw->clk_rate = clk_round_rate(r->clock[0], hw->clk_rate);
+
+	/* SDR core timings are given in picoseconds */
+	period_ps = div_u64((u64)NSEC_PER_SEC * 1000, hw->clk_rate);
+
+	addr_setup_cycles = TO_CYCLES(sdr->tALS_min, period_ps);
+	data_setup_cycles = TO_CYCLES(sdr->tDS_min, period_ps);
+	data_hold_cycles = TO_CYCLES(sdr->tDH_min, period_ps);
+	busy_timeout_ps = max(sdr->tBERS_max, sdr->tPROG_max);
+	busy_timeout_cycles = TO_CYCLES(busy_timeout_ps, period_ps);
+
+	hw->timing0 = BF_GPMI_TIMING0_ADDRESS_SETUP(addr_setup_cycles) |
+		      BF_GPMI_TIMING0_DATA_HOLD(data_hold_cycles) |
+		      BF_GPMI_TIMING0_DATA_SETUP(data_setup_cycles);
+	hw->timing1 = BF_GPMI_TIMING1_BUSY_TIMEOUT(busy_timeout_cycles * 4096);
+
+	/*
+	 * Derive NFC ideal delay from {3}:
+	 *
+	 *                     (tREA + 4000 - tRP) * 8
+	 *         RDN_DELAY = -----------------------
+	 *                                RP
+	 */
+	if (period_ps > dll_threshold_ps) {
+		use_half_period = true;
+		reference_period_ps = period_ps / 2;
+	} else {
+		use_half_period = false;
+		reference_period_ps = period_ps;
+	}
+
+	tRP_ps = data_setup_cycles * period_ps;
+	sample_delay_ps = (sdr->tREA_max + 4000 - tRP_ps) * 8;
+	if (sample_delay_ps > 0)
+		sample_delay_factor = sample_delay_ps / reference_period_ps;
+	else
+		sample_delay_factor = 0;
+
+	hw->ctrl1n = BF_GPMI_CTRL1_WRN_DLY_SEL(wrn_dly_sel);
+	if (sample_delay_factor)
+		hw->ctrl1n |= BF_GPMI_CTRL1_RDN_DELAY(sample_delay_factor) |
+			      BM_GPMI_CTRL1_DLL_ENABLE |
+			      (use_half_period ? BM_GPMI_CTRL1_HALF_PERIOD : 0);
+}
+
+static int gpmi_nfc_apply_timings(struct gpmi_nand_data *this)
+{
+	struct gpmi_nfc_hardware_timing *hw = &this->hw;
+	struct resources *r = &this->resources;
+	void __iomem *gpmi_regs = r->gpmi_regs;
+	unsigned int dll_wait_time_us;
+	int ret;
+
+	/* Clock dividers do NOT guarantee a clean clock signal on its output
+	 * during the change of the divide factor on i.MX6Q/UL/SX. On i.MX7/8,
+	 * all clock dividers provide these guarantee.
+	 */
+	if (GPMI_IS_MX6Q(this) || GPMI_IS_MX6SX(this))
+		clk_disable_unprepare(r->clock[0]);
+
+	ret = clk_set_rate(r->clock[0], hw->clk_rate);
+	if (ret) {
+		dev_err(this->dev, "cannot set clock rate to %lu Hz: %d\n", hw->clk_rate, ret);
+		return ret;
+	}
+
+	if (GPMI_IS_MX6Q(this) || GPMI_IS_MX6SX(this)) {
+		ret = clk_prepare_enable(r->clock[0]);
+		if (ret)
+			return ret;
+	}
+
+	writel(hw->timing0, gpmi_regs + HW_GPMI_TIMING0);
+	writel(hw->timing1, gpmi_regs + HW_GPMI_TIMING1);
+
+	/*
+	 * Clear several CTRL1 fields, DLL must be disabled when setting
+	 * RDN_DELAY or HALF_PERIOD.
+	 */
+	writel(BM_GPMI_CTRL1_CLEAR_MASK, gpmi_regs + HW_GPMI_CTRL1_CLR);
+	writel(hw->ctrl1n, gpmi_regs + HW_GPMI_CTRL1_SET);
+
+	/* Wait 64 clock cycles before using the GPMI after enabling the DLL */
+	dll_wait_time_us = USEC_PER_SEC / hw->clk_rate * 64;
+	if (!dll_wait_time_us)
+		dll_wait_time_us = 1;
+
+	/* Wait for the DLL to settle. */
+	udelay(dll_wait_time_us);
+
+	return 0;
+}
+
+static int gpmi_setup_interface(struct nand_chip *chip, int chipnr,
+				const struct nand_interface_config *conf)
+{
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	const struct nand_sdr_timings *sdr;
+
+	/* Retrieve required NAND timings */
+	sdr = nand_get_sdr_timings(conf);
+	if (IS_ERR(sdr))
+		return PTR_ERR(sdr);
+
+	/* Only MX6 GPMI controller can reach EDO timings */
+	if (sdr->tRC_min <= 25000 && !GPMI_IS_MX6(this))
+		return -ENOTSUPP;
+
+	/* Stop here if this call was just a check */
+	if (chipnr < 0)
+		return 0;
+
+	/* Do the actual derivation of the controller timings */
+	gpmi_nfc_compute_timings(this, sdr);
+
+	this->hw.must_apply_timings = true;
+
+	return 0;
+}
+
+/* Clears a BCH interrupt. */
+static void gpmi_clear_bch(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	writel(BM_BCH_CTRL_COMPLETE_IRQ, r->bch_regs + HW_BCH_CTRL_CLR);
+}
+
+static struct dma_chan *get_dma_chan(struct gpmi_nand_data *this)
+{
+	/* We use the DMA channel 0 to access all the nand chips. */
+	return this->dma_chans[0];
+}
+
+/* This will be called after the DMA operation is finished. */
+static void dma_irq_callback(void *param)
+{
+	struct gpmi_nand_data *this = param;
+	struct completion *dma_c = &this->dma_done;
+
+	complete(dma_c);
+}
+
+static irqreturn_t bch_irq(int irq, void *cookie)
+{
+	struct gpmi_nand_data *this = cookie;
+
+	gpmi_clear_bch(this);
+	complete(&this->bch_done);
+	return IRQ_HANDLED;
+}
+
+static int gpmi_raw_len_to_len(struct gpmi_nand_data *this, int raw_len)
+{
+	/*
+	 * raw_len is the length to read/write including bch data which
+	 * we are passed in exec_op. Calculate the data length from it.
+	 */
+	if (this->bch)
+		return ALIGN_DOWN(raw_len, this->bch_geometry.ecc_chunk_size);
+	else
+		return raw_len;
+}
+
+/* Can we use the upper's buffer directly for DMA? */
+static bool prepare_data_dma(struct gpmi_nand_data *this, const void *buf,
+			     int raw_len, struct scatterlist *sgl,
+			     enum dma_data_direction dr)
+{
+	int ret;
+	int len = gpmi_raw_len_to_len(this, raw_len);
+
+	/* first try to map the upper buffer directly */
+	if (virt_addr_valid(buf) && !object_is_on_stack(buf)) {
+		sg_init_one(sgl, buf, len);
+		ret = dma_map_sg(this->dev, sgl, 1, dr);
+		if (ret == 0)
+			goto map_fail;
+
+		return true;
+	}
+
+map_fail:
+	/* We have to use our own DMA buffer. */
+	sg_init_one(sgl, this->data_buffer_dma, len);
+
+	if (dr == DMA_TO_DEVICE && buf != this->data_buffer_dma)
+		memcpy(this->data_buffer_dma, buf, len);
+
+	dma_map_sg(this->dev, sgl, 1, dr);
+
+	return false;
+}
+
+/* add our owner bbt descriptor */
+static uint8_t scan_ff_pattern[] = { 0xff };
+static struct nand_bbt_descr gpmi_bbt_descr = {
+	.options	= 0,
+	.offs		= 0,
+	.len		= 1,
+	.pattern	= scan_ff_pattern
+};
+
+/*
+ * We may change the layout if we can get the ECC info from the datasheet,
+ * else we will use all the (page + OOB).
+ */
+static int gpmi_ooblayout_ecc(struct mtd_info *mtd, int section,
+			      struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *geo = &this->bch_geometry;
+
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = 0;
+	oobregion->length = geo->page_size - mtd->writesize;
+
+	return 0;
+}
+
+static int gpmi_ooblayout_free(struct mtd_info *mtd, int section,
+			       struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *geo = &this->bch_geometry;
+
+	if (section)
+		return -ERANGE;
+
+	/* The available oob size we have. */
+	if (geo->page_size < mtd->writesize + mtd->oobsize) {
+		oobregion->offset = geo->page_size - mtd->writesize;
+		oobregion->length = mtd->oobsize - oobregion->offset;
+	}
+
+	return 0;
+}
+
+static const char * const gpmi_clks_for_mx2x[] = {
+	"gpmi_io",
+};
+
+static const struct mtd_ooblayout_ops gpmi_ooblayout_ops = {
+	.ecc = gpmi_ooblayout_ecc,
+	.free = gpmi_ooblayout_free,
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx23 = {
+	.type = IS_MX23,
+	.bch_max_ecc_strength = 20,
+	.max_chain_delay = 16000,
+	.clks = gpmi_clks_for_mx2x,
+	.clks_count = ARRAY_SIZE(gpmi_clks_for_mx2x),
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx28 = {
+	.type = IS_MX28,
+	.bch_max_ecc_strength = 20,
+	.max_chain_delay = 16000,
+	.clks = gpmi_clks_for_mx2x,
+	.clks_count = ARRAY_SIZE(gpmi_clks_for_mx2x),
+};
+
+static const char * const gpmi_clks_for_mx6[] = {
+	"gpmi_io", "gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch",
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx6q = {
+	.type = IS_MX6Q,
+	.bch_max_ecc_strength = 40,
+	.max_chain_delay = 12000,
+	.clks = gpmi_clks_for_mx6,
+	.clks_count = ARRAY_SIZE(gpmi_clks_for_mx6),
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx6sx = {
+	.type = IS_MX6SX,
+	.bch_max_ecc_strength = 62,
+	.max_chain_delay = 12000,
+	.clks = gpmi_clks_for_mx6,
+	.clks_count = ARRAY_SIZE(gpmi_clks_for_mx6),
+};
+
+static const char * const gpmi_clks_for_mx7d[] = {
+	"gpmi_io", "gpmi_bch_apb",
+};
+
+static const struct gpmi_devdata gpmi_devdata_imx7d = {
+	.type = IS_MX7D,
+	.bch_max_ecc_strength = 62,
+	.max_chain_delay = 12000,
+	.clks = gpmi_clks_for_mx7d,
+	.clks_count = ARRAY_SIZE(gpmi_clks_for_mx7d),
+};
+
+static int acquire_register_block(struct gpmi_nand_data *this,
+				  const char *res_name)
+{
+	struct platform_device *pdev = this->pdev;
+	struct resources *res = &this->resources;
+	struct resource *r;
+	void __iomem *p;
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, res_name);
+	p = devm_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(p))
+		return PTR_ERR(p);
+
+	if (!strcmp(res_name, GPMI_NAND_GPMI_REGS_ADDR_RES_NAME))
+		res->gpmi_regs = p;
+	else if (!strcmp(res_name, GPMI_NAND_BCH_REGS_ADDR_RES_NAME))
+		res->bch_regs = p;
+	else
+		dev_err(this->dev, "unknown resource name : %s\n", res_name);
+
+	return 0;
+}
+
+static int acquire_bch_irq(struct gpmi_nand_data *this, irq_handler_t irq_h)
+{
+	struct platform_device *pdev = this->pdev;
+	const char *res_name = GPMI_NAND_BCH_INTERRUPT_RES_NAME;
+	struct resource *r;
+	int err;
+
+	r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, res_name);
+	if (!r) {
+		dev_err(this->dev, "Can't get resource for %s\n", res_name);
+		return -ENODEV;
+	}
+
+	err = devm_request_irq(this->dev, r->start, irq_h, 0, res_name, this);
+	if (err)
+		dev_err(this->dev, "error requesting BCH IRQ\n");
+
+	return err;
+}
+
+static void release_dma_channels(struct gpmi_nand_data *this)
+{
+	unsigned int i;
+	for (i = 0; i < DMA_CHANS; i++)
+		if (this->dma_chans[i]) {
+			dma_release_channel(this->dma_chans[i]);
+			this->dma_chans[i] = NULL;
+		}
+}
+
+static int acquire_dma_channels(struct gpmi_nand_data *this)
+{
+	struct platform_device *pdev = this->pdev;
+	struct dma_chan *dma_chan;
+	int ret = 0;
+
+	/* request dma channel */
+	dma_chan = dma_request_chan(&pdev->dev, "rx-tx");
+	if (IS_ERR(dma_chan)) {
+		ret = dev_err_probe(this->dev, PTR_ERR(dma_chan),
+				    "DMA channel request failed\n");
+		release_dma_channels(this);
+	} else {
+		this->dma_chans[0] = dma_chan;
+	}
+
+	return ret;
+}
+
+static int gpmi_get_clks(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	struct clk *clk;
+	int err, i;
+
+	for (i = 0; i < this->devdata->clks_count; i++) {
+		clk = devm_clk_get(this->dev, this->devdata->clks[i]);
+		if (IS_ERR(clk)) {
+			err = PTR_ERR(clk);
+			goto err_clock;
+		}
+
+		r->clock[i] = clk;
+	}
+
+	return 0;
+
+err_clock:
+	dev_dbg(this->dev, "failed in finding the clocks.\n");
+	return err;
+}
+
+static int acquire_resources(struct gpmi_nand_data *this)
+{
+	int ret;
+
+	ret = acquire_register_block(this, GPMI_NAND_GPMI_REGS_ADDR_RES_NAME);
+	if (ret)
+		goto exit_regs;
+
+	ret = acquire_register_block(this, GPMI_NAND_BCH_REGS_ADDR_RES_NAME);
+	if (ret)
+		goto exit_regs;
+
+	ret = acquire_bch_irq(this, bch_irq);
+	if (ret)
+		goto exit_regs;
+
+	ret = acquire_dma_channels(this);
+	if (ret)
+		goto exit_regs;
+
+	ret = gpmi_get_clks(this);
+	if (ret)
+		goto exit_clock;
+	return 0;
+
+exit_clock:
+	release_dma_channels(this);
+exit_regs:
+	return ret;
+}
+
+static void release_resources(struct gpmi_nand_data *this)
+{
+	release_dma_channels(this);
+}
+
+static void gpmi_free_dma_buffer(struct gpmi_nand_data *this)
+{
+	struct device *dev = this->dev;
+	struct bch_geometry *geo = &this->bch_geometry;
+
+	if (this->auxiliary_virt && virt_addr_valid(this->auxiliary_virt))
+		dma_free_coherent(dev, geo->auxiliary_size,
+					this->auxiliary_virt,
+					this->auxiliary_phys);
+	kfree(this->data_buffer_dma);
+	kfree(this->raw_buffer);
+
+	this->data_buffer_dma	= NULL;
+	this->raw_buffer	= NULL;
+}
+
+/* Allocate the DMA buffers */
+static int gpmi_alloc_dma_buffer(struct gpmi_nand_data *this)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	struct device *dev = this->dev;
+	struct mtd_info *mtd = nand_to_mtd(&this->nand);
+
+	/*
+	 * [2] Allocate a read/write data buffer.
+	 *     The gpmi_alloc_dma_buffer can be called twice.
+	 *     We allocate a PAGE_SIZE length buffer if gpmi_alloc_dma_buffer
+	 *     is called before the NAND identification; and we allocate a
+	 *     buffer of the real NAND page size when the gpmi_alloc_dma_buffer
+	 *     is called after.
+	 */
+	this->data_buffer_dma = kzalloc(mtd->writesize ?: PAGE_SIZE,
+					GFP_DMA | GFP_KERNEL);
+	if (this->data_buffer_dma == NULL)
+		goto error_alloc;
+
+	this->auxiliary_virt = dma_alloc_coherent(dev, geo->auxiliary_size,
+					&this->auxiliary_phys, GFP_DMA);
+	if (!this->auxiliary_virt)
+		goto error_alloc;
+
+	this->raw_buffer = kzalloc((mtd->writesize ?: PAGE_SIZE) + mtd->oobsize, GFP_KERNEL);
+	if (!this->raw_buffer)
+		goto error_alloc;
+
+	return 0;
+
+error_alloc:
+	gpmi_free_dma_buffer(this);
+	return -ENOMEM;
+}
+
+/*
+ * Handles block mark swapping.
+ * It can be called in swapping the block mark, or swapping it back,
+ * because the the operations are the same.
+ */
+static void block_mark_swapping(struct gpmi_nand_data *this,
+				void *payload, void *auxiliary)
+{
+	struct bch_geometry *nfc_geo = &this->bch_geometry;
+	unsigned char *p;
+	unsigned char *a;
+	unsigned int  bit;
+	unsigned char mask;
+	unsigned char from_data;
+	unsigned char from_oob;
+
+	if (!this->swap_block_mark)
+		return;
+
+	/*
+	 * If control arrives here, we're swapping. Make some convenience
+	 * variables.
+	 */
+	bit = nfc_geo->block_mark_bit_offset;
+	p   = payload + nfc_geo->block_mark_byte_offset;
+	a   = auxiliary;
+
+	/*
+	 * Get the byte from the data area that overlays the block mark. Since
+	 * the ECC engine applies its own view to the bits in the page, the
+	 * physical block mark won't (in general) appear on a byte boundary in
+	 * the data.
+	 */
+	from_data = (p[0] >> bit) | (p[1] << (8 - bit));
+
+	/* Get the byte from the OOB. */
+	from_oob = a[0];
+
+	/* Swap them. */
+	a[0] = from_data;
+
+	mask = (0x1 << bit) - 1;
+	p[0] = (p[0] & mask) | (from_oob << bit);
+
+	mask = ~0 << bit;
+	p[1] = (p[1] & mask) | (from_oob >> (8 - bit));
+}
+
+static int gpmi_count_bitflips(struct nand_chip *chip, void *buf, int first,
+			       int last, int meta)
+{
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *nfc_geo = &this->bch_geometry;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int i;
+	unsigned char *status;
+	unsigned int max_bitflips = 0;
+
+	/* Loop over status bytes, accumulating ECC status. */
+	status = this->auxiliary_virt + ALIGN(meta, 4);
+
+	for (i = first; i < last; i++, status++) {
+		if ((*status == STATUS_GOOD) || (*status == STATUS_ERASED))
+			continue;
+
+		if (*status == STATUS_UNCORRECTABLE) {
+			int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
+			u8 *eccbuf = this->raw_buffer;
+			int offset, bitoffset;
+			int eccbytes;
+			int flips;
+
+			/* Read ECC bytes into our internal raw_buffer */
+			offset = nfc_geo->metadata_size * 8;
+			offset += ((8 * nfc_geo->ecc_chunk_size) + eccbits) * (i + 1);
+			offset -= eccbits;
+			bitoffset = offset % 8;
+			eccbytes = DIV_ROUND_UP(offset + eccbits, 8);
+			offset /= 8;
+			eccbytes -= offset;
+			nand_change_read_column_op(chip, offset, eccbuf,
+						   eccbytes, false);
+
+			/*
+			 * ECC data are not byte aligned and we may have
+			 * in-band data in the first and last byte of
+			 * eccbuf. Set non-eccbits to one so that
+			 * nand_check_erased_ecc_chunk() does not count them
+			 * as bitflips.
+			 */
+			if (bitoffset)
+				eccbuf[0] |= GENMASK(bitoffset - 1, 0);
+
+			bitoffset = (bitoffset + eccbits) % 8;
+			if (bitoffset)
+				eccbuf[eccbytes - 1] |= GENMASK(7, bitoffset);
+
+			/*
+			 * The ECC hardware has an uncorrectable ECC status
+			 * code in case we have bitflips in an erased page. As
+			 * nothing was written into this subpage the ECC is
+			 * obviously wrong and we can not trust it. We assume
+			 * at this point that we are reading an erased page and
+			 * try to correct the bitflips in buffer up to
+			 * ecc_strength bitflips. If this is a page with random
+			 * data, we exceed this number of bitflips and have a
+			 * ECC failure. Otherwise we use the corrected buffer.
+			 */
+			if (i == 0) {
+				/* The first block includes metadata */
+				flips = nand_check_erased_ecc_chunk(
+						buf + i * nfc_geo->ecc_chunk_size,
+						nfc_geo->ecc_chunk_size,
+						eccbuf, eccbytes,
+						this->auxiliary_virt,
+						nfc_geo->metadata_size,
+						nfc_geo->ecc_strength);
+			} else {
+				flips = nand_check_erased_ecc_chunk(
+						buf + i * nfc_geo->ecc_chunk_size,
+						nfc_geo->ecc_chunk_size,
+						eccbuf, eccbytes,
+						NULL, 0,
+						nfc_geo->ecc_strength);
+			}
+
+			if (flips > 0) {
+				max_bitflips = max_t(unsigned int, max_bitflips,
+						     flips);
+				mtd->ecc_stats.corrected += flips;
+				continue;
+			}
+
+			mtd->ecc_stats.failed++;
+			continue;
+		}
+
+		mtd->ecc_stats.corrected += *status;
+		max_bitflips = max_t(unsigned int, max_bitflips, *status);
+	}
+
+	return max_bitflips;
+}
+
+static void gpmi_bch_layout_std(struct gpmi_nand_data *this)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	unsigned int ecc_strength = geo->ecc_strength >> 1;
+	unsigned int gf_len = geo->gf_len;
+	unsigned int block_size = geo->ecc_chunk_size;
+
+	this->bch_flashlayout0 =
+		BF_BCH_FLASH0LAYOUT0_NBLOCKS(geo->ecc_chunk_count - 1) |
+		BF_BCH_FLASH0LAYOUT0_META_SIZE(geo->metadata_size) |
+		BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) |
+		BF_BCH_FLASH0LAYOUT0_GF(gf_len, this) |
+		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(block_size, this);
+
+	this->bch_flashlayout1 =
+		BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(geo->page_size) |
+		BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) |
+		BF_BCH_FLASH0LAYOUT1_GF(gf_len, this) |
+		BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(block_size, this);
+}
+
+static int gpmi_ecc_read_page(struct nand_chip *chip, uint8_t *buf,
+			      int oob_required, int page)
+{
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct bch_geometry *geo = &this->bch_geometry;
+	unsigned int max_bitflips;
+	int ret;
+
+	gpmi_bch_layout_std(this);
+	this->bch = true;
+
+	ret = nand_read_page_op(chip, page, 0, buf, geo->page_size);
+	if (ret)
+		return ret;
+
+	max_bitflips = gpmi_count_bitflips(chip, buf, 0,
+					   geo->ecc_chunk_count,
+					   geo->auxiliary_status_offset);
+
+	/* handle the block mark swapping */
+	block_mark_swapping(this, buf, this->auxiliary_virt);
+
+	if (oob_required) {
+		/*
+		 * It's time to deliver the OOB bytes. See gpmi_ecc_read_oob()
+		 * for details about our policy for delivering the OOB.
+		 *
+		 * We fill the caller's buffer with set bits, and then copy the
+		 * block mark to th caller's buffer. Note that, if block mark
+		 * swapping was necessary, it has already been done, so we can
+		 * rely on the first byte of the auxiliary buffer to contain
+		 * the block mark.
+		 */
+		memset(chip->oob_poi, ~0, mtd->oobsize);
+		chip->oob_poi[0] = ((uint8_t *)this->auxiliary_virt)[0];
+	}
+
+	return max_bitflips;
+}
+
+/* Fake a virtual small page for the subpage read */
+static int gpmi_ecc_read_subpage(struct nand_chip *chip, uint32_t offs,
+				 uint32_t len, uint8_t *buf, int page)
+{
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *geo = &this->bch_geometry;
+	int size = chip->ecc.size; /* ECC chunk size */
+	int meta, n, page_size;
+	unsigned int max_bitflips;
+	unsigned int ecc_strength;
+	int first, last, marker_pos;
+	int ecc_parity_size;
+	int col = 0;
+	int ret;
+
+	/* The size of ECC parity */
+	ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
+
+	/* Align it with the chunk size */
+	first = offs / size;
+	last = (offs + len - 1) / size;
+
+	if (this->swap_block_mark) {
+		/*
+		 * Find the chunk which contains the Block Marker.
+		 * If this chunk is in the range of [first, last],
+		 * we have to read out the whole page.
+		 * Why? since we had swapped the data at the position of Block
+		 * Marker to the metadata which is bound with the chunk 0.
+		 */
+		marker_pos = geo->block_mark_byte_offset / size;
+		if (last >= marker_pos && first <= marker_pos) {
+			dev_dbg(this->dev,
+				"page:%d, first:%d, last:%d, marker at:%d\n",
+				page, first, last, marker_pos);
+			return gpmi_ecc_read_page(chip, buf, 0, page);
+		}
+	}
+
+	meta = geo->metadata_size;
+	if (first) {
+		col = meta + (size + ecc_parity_size) * first;
+		meta = 0;
+		buf = buf + first * size;
+	}
+
+	ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
+
+	n = last - first + 1;
+	page_size = meta + (size + ecc_parity_size) * n;
+	ecc_strength = geo->ecc_strength >> 1;
+
+	this->bch_flashlayout0 = BF_BCH_FLASH0LAYOUT0_NBLOCKS(n - 1) |
+		BF_BCH_FLASH0LAYOUT0_META_SIZE(meta) |
+		BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) |
+		BF_BCH_FLASH0LAYOUT0_GF(geo->gf_len, this) |
+		BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(geo->ecc_chunk_size, this);
+
+	this->bch_flashlayout1 = BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size) |
+		BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) |
+		BF_BCH_FLASH0LAYOUT1_GF(geo->gf_len, this) |
+		BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(geo->ecc_chunk_size, this);
+
+	this->bch = true;
+
+	ret = nand_read_page_op(chip, page, col, buf, page_size);
+	if (ret)
+		return ret;
+
+	dev_dbg(this->dev, "page:%d(%d:%d)%d, chunk:(%d:%d), BCH PG size:%d\n",
+		page, offs, len, col, first, n, page_size);
+
+	max_bitflips = gpmi_count_bitflips(chip, buf, first, last, meta);
+
+	return max_bitflips;
+}
+
+static int gpmi_ecc_write_page(struct nand_chip *chip, const uint8_t *buf,
+			       int oob_required, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *nfc_geo = &this->bch_geometry;
+	int ret;
+
+	dev_dbg(this->dev, "ecc write page.\n");
+
+	gpmi_bch_layout_std(this);
+	this->bch = true;
+
+	memcpy(this->auxiliary_virt, chip->oob_poi, nfc_geo->auxiliary_size);
+
+	if (this->swap_block_mark) {
+		/*
+		 * When doing bad block marker swapping we must always copy the
+		 * input buffer as we can't modify the const buffer.
+		 */
+		memcpy(this->data_buffer_dma, buf, mtd->writesize);
+		buf = this->data_buffer_dma;
+		block_mark_swapping(this, this->data_buffer_dma,
+				    this->auxiliary_virt);
+	}
+
+	ret = nand_prog_page_op(chip, page, 0, buf, nfc_geo->page_size);
+
+	return ret;
+}
+
+/*
+ * There are several places in this driver where we have to handle the OOB and
+ * block marks. This is the function where things are the most complicated, so
+ * this is where we try to explain it all. All the other places refer back to
+ * here.
+ *
+ * These are the rules, in order of decreasing importance:
+ *
+ * 1) Nothing the caller does can be allowed to imperil the block mark.
+ *
+ * 2) In read operations, the first byte of the OOB we return must reflect the
+ *    true state of the block mark, no matter where that block mark appears in
+ *    the physical page.
+ *
+ * 3) ECC-based read operations return an OOB full of set bits (since we never
+ *    allow ECC-based writes to the OOB, it doesn't matter what ECC-based reads
+ *    return).
+ *
+ * 4) "Raw" read operations return a direct view of the physical bytes in the
+ *    page, using the conventional definition of which bytes are data and which
+ *    are OOB. This gives the caller a way to see the actual, physical bytes
+ *    in the page, without the distortions applied by our ECC engine.
+ *
+ *
+ * What we do for this specific read operation depends on two questions:
+ *
+ * 1) Are we doing a "raw" read, or an ECC-based read?
+ *
+ * 2) Are we using block mark swapping or transcription?
+ *
+ * There are four cases, illustrated by the following Karnaugh map:
+ *
+ *                    |           Raw           |         ECC-based       |
+ *       -------------+-------------------------+-------------------------+
+ *                    | Read the conventional   |                         |
+ *                    | OOB at the end of the   |                         |
+ *       Swapping     | page and return it. It  |                         |
+ *                    | contains exactly what   |                         |
+ *                    | we want.                | Read the block mark and |
+ *       -------------+-------------------------+ return it in a buffer   |
+ *                    | Read the conventional   | full of set bits.       |
+ *                    | OOB at the end of the   |                         |
+ *                    | page and also the block |                         |
+ *       Transcribing | mark in the metadata.   |                         |
+ *                    | Copy the block mark     |                         |
+ *                    | into the first byte of  |                         |
+ *                    | the OOB.                |                         |
+ *       -------------+-------------------------+-------------------------+
+ *
+ * Note that we break rule #4 in the Transcribing/Raw case because we're not
+ * giving an accurate view of the actual, physical bytes in the page (we're
+ * overwriting the block mark). That's OK because it's more important to follow
+ * rule #2.
+ *
+ * It turns out that knowing whether we want an "ECC-based" or "raw" read is not
+ * easy. When reading a page, for example, the NAND Flash MTD code calls our
+ * ecc.read_page or ecc.read_page_raw function. Thus, the fact that MTD wants an
+ * ECC-based or raw view of the page is implicit in which function it calls
+ * (there is a similar pair of ECC-based/raw functions for writing).
+ */
+static int gpmi_ecc_read_oob(struct nand_chip *chip, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	int ret;
+
+	/* clear the OOB buffer */
+	memset(chip->oob_poi, ~0, mtd->oobsize);
+
+	/* Read out the conventional OOB. */
+	ret = nand_read_page_op(chip, page, mtd->writesize, chip->oob_poi,
+				mtd->oobsize);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now, we want to make sure the block mark is correct. In the
+	 * non-transcribing case (!GPMI_IS_MX23()), we already have it.
+	 * Otherwise, we need to explicitly read it.
+	 */
+	if (GPMI_IS_MX23(this)) {
+		/* Read the block mark into the first byte of the OOB buffer. */
+		ret = nand_read_page_op(chip, page, 0, chip->oob_poi, 1);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int gpmi_ecc_write_oob(struct nand_chip *chip, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct mtd_oob_region of = { };
+
+	/* Do we have available oob area? */
+	mtd_ooblayout_free(mtd, 0, &of);
+	if (!of.length)
+		return -EPERM;
+
+	if (!nand_is_slc(chip))
+		return -EPERM;
+
+	return nand_prog_page_op(chip, page, mtd->writesize + of.offset,
+				 chip->oob_poi + of.offset, of.length);
+}
+
+/*
+ * This function reads a NAND page without involving the ECC engine (no HW
+ * ECC correction).
+ * The tricky part in the GPMI/BCH controller is that it stores ECC bits
+ * inline (interleaved with payload DATA), and do not align data chunk on
+ * byte boundaries.
+ * We thus need to take care moving the payload data and ECC bits stored in the
+ * page into the provided buffers, which is why we're using nand_extract_bits().
+ *
+ * See set_geometry_by_ecc_info inline comments to have a full description
+ * of the layout used by the GPMI controller.
+ */
+static int gpmi_ecc_read_page_raw(struct nand_chip *chip, uint8_t *buf,
+				  int oob_required, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *nfc_geo = &this->bch_geometry;
+	int eccsize = nfc_geo->ecc_chunk_size;
+	int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
+	u8 *tmp_buf = this->raw_buffer;
+	size_t src_bit_off;
+	size_t oob_bit_off;
+	size_t oob_byte_off;
+	uint8_t *oob = chip->oob_poi;
+	int step;
+	int ret;
+
+	ret = nand_read_page_op(chip, page, 0, tmp_buf,
+				mtd->writesize + mtd->oobsize);
+	if (ret)
+		return ret;
+
+	/*
+	 * If required, swap the bad block marker and the data stored in the
+	 * metadata section, so that we don't wrongly consider a block as bad.
+	 *
+	 * See the layout description for a detailed explanation on why this
+	 * is needed.
+	 */
+	if (this->swap_block_mark)
+		swap(tmp_buf[0], tmp_buf[mtd->writesize]);
+
+	/*
+	 * Copy the metadata section into the oob buffer (this section is
+	 * guaranteed to be aligned on a byte boundary).
+	 */
+	if (oob_required)
+		memcpy(oob, tmp_buf, nfc_geo->metadata_size);
+
+	oob_bit_off = nfc_geo->metadata_size * 8;
+	src_bit_off = oob_bit_off;
+
+	/* Extract interleaved payload data and ECC bits */
+	for (step = 0; step < nfc_geo->ecc_chunk_count; step++) {
+		if (buf)
+			nand_extract_bits(buf, step * eccsize * 8, tmp_buf,
+					  src_bit_off, eccsize * 8);
+		src_bit_off += eccsize * 8;
+
+		/* Align last ECC block to align a byte boundary */
+		if (step == nfc_geo->ecc_chunk_count - 1 &&
+		    (oob_bit_off + eccbits) % 8)
+			eccbits += 8 - ((oob_bit_off + eccbits) % 8);
+
+		if (oob_required)
+			nand_extract_bits(oob, oob_bit_off, tmp_buf,
+					  src_bit_off, eccbits);
+
+		src_bit_off += eccbits;
+		oob_bit_off += eccbits;
+	}
+
+	if (oob_required) {
+		oob_byte_off = oob_bit_off / 8;
+
+		if (oob_byte_off < mtd->oobsize)
+			memcpy(oob + oob_byte_off,
+			       tmp_buf + mtd->writesize + oob_byte_off,
+			       mtd->oobsize - oob_byte_off);
+	}
+
+	return 0;
+}
+
+/*
+ * This function writes a NAND page without involving the ECC engine (no HW
+ * ECC generation).
+ * The tricky part in the GPMI/BCH controller is that it stores ECC bits
+ * inline (interleaved with payload DATA), and do not align data chunk on
+ * byte boundaries.
+ * We thus need to take care moving the OOB area at the right place in the
+ * final page, which is why we're using nand_extract_bits().
+ *
+ * See set_geometry_by_ecc_info inline comments to have a full description
+ * of the layout used by the GPMI controller.
+ */
+static int gpmi_ecc_write_page_raw(struct nand_chip *chip, const uint8_t *buf,
+				   int oob_required, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct bch_geometry *nfc_geo = &this->bch_geometry;
+	int eccsize = nfc_geo->ecc_chunk_size;
+	int eccbits = nfc_geo->ecc_strength * nfc_geo->gf_len;
+	u8 *tmp_buf = this->raw_buffer;
+	uint8_t *oob = chip->oob_poi;
+	size_t dst_bit_off;
+	size_t oob_bit_off;
+	size_t oob_byte_off;
+	int step;
+
+	/*
+	 * Initialize all bits to 1 in case we don't have a buffer for the
+	 * payload or oob data in order to leave unspecified bits of data
+	 * to their initial state.
+	 */
+	if (!buf || !oob_required)
+		memset(tmp_buf, 0xff, mtd->writesize + mtd->oobsize);
+
+	/*
+	 * First copy the metadata section (stored in oob buffer) at the
+	 * beginning of the page, as imposed by the GPMI layout.
+	 */
+	memcpy(tmp_buf, oob, nfc_geo->metadata_size);
+	oob_bit_off = nfc_geo->metadata_size * 8;
+	dst_bit_off = oob_bit_off;
+
+	/* Interleave payload data and ECC bits */
+	for (step = 0; step < nfc_geo->ecc_chunk_count; step++) {
+		if (buf)
+			nand_extract_bits(tmp_buf, dst_bit_off, buf,
+					  step * eccsize * 8, eccsize * 8);
+		dst_bit_off += eccsize * 8;
+
+		/* Align last ECC block to align a byte boundary */
+		if (step == nfc_geo->ecc_chunk_count - 1 &&
+		    (oob_bit_off + eccbits) % 8)
+			eccbits += 8 - ((oob_bit_off + eccbits) % 8);
+
+		if (oob_required)
+			nand_extract_bits(tmp_buf, dst_bit_off, oob,
+					  oob_bit_off, eccbits);
+
+		dst_bit_off += eccbits;
+		oob_bit_off += eccbits;
+	}
+
+	oob_byte_off = oob_bit_off / 8;
+
+	if (oob_required && oob_byte_off < mtd->oobsize)
+		memcpy(tmp_buf + mtd->writesize + oob_byte_off,
+		       oob + oob_byte_off, mtd->oobsize - oob_byte_off);
+
+	/*
+	 * If required, swap the bad block marker and the first byte of the
+	 * metadata section, so that we don't modify the bad block marker.
+	 *
+	 * See the layout description for a detailed explanation on why this
+	 * is needed.
+	 */
+	if (this->swap_block_mark)
+		swap(tmp_buf[0], tmp_buf[mtd->writesize]);
+
+	return nand_prog_page_op(chip, page, 0, tmp_buf,
+				 mtd->writesize + mtd->oobsize);
+}
+
+static int gpmi_ecc_read_oob_raw(struct nand_chip *chip, int page)
+{
+	return gpmi_ecc_read_page_raw(chip, NULL, 1, page);
+}
+
+static int gpmi_ecc_write_oob_raw(struct nand_chip *chip, int page)
+{
+	return gpmi_ecc_write_page_raw(chip, NULL, 1, page);
+}
+
+static int gpmi_block_markbad(struct nand_chip *chip, loff_t ofs)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	int ret = 0;
+	uint8_t *block_mark;
+	int column, page, chipnr;
+
+	chipnr = (int)(ofs >> chip->chip_shift);
+	nand_select_target(chip, chipnr);
+
+	column = !GPMI_IS_MX23(this) ? mtd->writesize : 0;
+
+	/* Write the block mark. */
+	block_mark = this->data_buffer_dma;
+	block_mark[0] = 0; /* bad block marker */
+
+	/* Shift to get page */
+	page = (int)(ofs >> chip->page_shift);
+
+	ret = nand_prog_page_op(chip, page, column, block_mark, 1);
+
+	nand_deselect_target(chip);
+
+	return ret;
+}
+
+static int nand_boot_set_geometry(struct gpmi_nand_data *this)
+{
+	struct boot_rom_geometry *geometry = &this->rom_geometry;
+
+	/*
+	 * Set the boot block stride size.
+	 *
+	 * In principle, we should be reading this from the OTP bits, since
+	 * that's where the ROM is going to get it. In fact, we don't have any
+	 * way to read the OTP bits, so we go with the default and hope for the
+	 * best.
+	 */
+	geometry->stride_size_in_pages = 64;
+
+	/*
+	 * Set the search area stride exponent.
+	 *
+	 * In principle, we should be reading this from the OTP bits, since
+	 * that's where the ROM is going to get it. In fact, we don't have any
+	 * way to read the OTP bits, so we go with the default and hope for the
+	 * best.
+	 */
+	geometry->search_area_stride_exponent = 2;
+	return 0;
+}
+
+static const char  *fingerprint = "STMP";
+static int mx23_check_transcription_stamp(struct gpmi_nand_data *this)
+{
+	struct boot_rom_geometry *rom_geo = &this->rom_geometry;
+	struct device *dev = this->dev;
+	struct nand_chip *chip = &this->nand;
+	unsigned int search_area_size_in_strides;
+	unsigned int stride;
+	unsigned int page;
+	u8 *buffer = nand_get_data_buf(chip);
+	int found_an_ncb_fingerprint = false;
+	int ret;
+
+	/* Compute the number of strides in a search area. */
+	search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
+
+	nand_select_target(chip, 0);
+
+	/*
+	 * Loop through the first search area, looking for the NCB fingerprint.
+	 */
+	dev_dbg(dev, "Scanning for an NCB fingerprint...\n");
+
+	for (stride = 0; stride < search_area_size_in_strides; stride++) {
+		/* Compute the page addresses. */
+		page = stride * rom_geo->stride_size_in_pages;
+
+		dev_dbg(dev, "Looking for a fingerprint in page 0x%x\n", page);
+
+		/*
+		 * Read the NCB fingerprint. The fingerprint is four bytes long
+		 * and starts in the 12th byte of the page.
+		 */
+		ret = nand_read_page_op(chip, page, 12, buffer,
+					strlen(fingerprint));
+		if (ret)
+			continue;
+
+		/* Look for the fingerprint. */
+		if (!memcmp(buffer, fingerprint, strlen(fingerprint))) {
+			found_an_ncb_fingerprint = true;
+			break;
+		}
+
+	}
+
+	nand_deselect_target(chip);
+
+	if (found_an_ncb_fingerprint)
+		dev_dbg(dev, "\tFound a fingerprint\n");
+	else
+		dev_dbg(dev, "\tNo fingerprint found\n");
+	return found_an_ncb_fingerprint;
+}
+
+/* Writes a transcription stamp. */
+static int mx23_write_transcription_stamp(struct gpmi_nand_data *this)
+{
+	struct device *dev = this->dev;
+	struct boot_rom_geometry *rom_geo = &this->rom_geometry;
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int block_size_in_pages;
+	unsigned int search_area_size_in_strides;
+	unsigned int search_area_size_in_pages;
+	unsigned int search_area_size_in_blocks;
+	unsigned int block;
+	unsigned int stride;
+	unsigned int page;
+	u8 *buffer = nand_get_data_buf(chip);
+	int status;
+
+	/* Compute the search area geometry. */
+	block_size_in_pages = mtd->erasesize / mtd->writesize;
+	search_area_size_in_strides = 1 << rom_geo->search_area_stride_exponent;
+	search_area_size_in_pages = search_area_size_in_strides *
+					rom_geo->stride_size_in_pages;
+	search_area_size_in_blocks =
+		  (search_area_size_in_pages + (block_size_in_pages - 1)) /
+				    block_size_in_pages;
+
+	dev_dbg(dev, "Search Area Geometry :\n");
+	dev_dbg(dev, "\tin Blocks : %u\n", search_area_size_in_blocks);
+	dev_dbg(dev, "\tin Strides: %u\n", search_area_size_in_strides);
+	dev_dbg(dev, "\tin Pages  : %u\n", search_area_size_in_pages);
+
+	nand_select_target(chip, 0);
+
+	/* Loop over blocks in the first search area, erasing them. */
+	dev_dbg(dev, "Erasing the search area...\n");
+
+	for (block = 0; block < search_area_size_in_blocks; block++) {
+		/* Erase this block. */
+		dev_dbg(dev, "\tErasing block 0x%x\n", block);
+		status = nand_erase_op(chip, block);
+		if (status)
+			dev_err(dev, "[%s] Erase failed.\n", __func__);
+	}
+
+	/* Write the NCB fingerprint into the page buffer. */
+	memset(buffer, ~0, mtd->writesize);
+	memcpy(buffer + 12, fingerprint, strlen(fingerprint));
+
+	/* Loop through the first search area, writing NCB fingerprints. */
+	dev_dbg(dev, "Writing NCB fingerprints...\n");
+	for (stride = 0; stride < search_area_size_in_strides; stride++) {
+		/* Compute the page addresses. */
+		page = stride * rom_geo->stride_size_in_pages;
+
+		/* Write the first page of the current stride. */
+		dev_dbg(dev, "Writing an NCB fingerprint in page 0x%x\n", page);
+
+		status = chip->ecc.write_page_raw(chip, buffer, 0, page);
+		if (status)
+			dev_err(dev, "[%s] Write failed.\n", __func__);
+	}
+
+	nand_deselect_target(chip);
+
+	return 0;
+}
+
+static int mx23_boot_init(struct gpmi_nand_data  *this)
+{
+	struct device *dev = this->dev;
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int block_count;
+	unsigned int block;
+	int     chipnr;
+	int     page;
+	loff_t  byte;
+	uint8_t block_mark;
+	int     ret = 0;
+
+	/*
+	 * If control arrives here, we can't use block mark swapping, which
+	 * means we're forced to use transcription. First, scan for the
+	 * transcription stamp. If we find it, then we don't have to do
+	 * anything -- the block marks are already transcribed.
+	 */
+	if (mx23_check_transcription_stamp(this))
+		return 0;
+
+	/*
+	 * If control arrives here, we couldn't find a transcription stamp, so
+	 * so we presume the block marks are in the conventional location.
+	 */
+	dev_dbg(dev, "Transcribing bad block marks...\n");
+
+	/* Compute the number of blocks in the entire medium. */
+	block_count = nanddev_eraseblocks_per_target(&chip->base);
+
+	/*
+	 * Loop over all the blocks in the medium, transcribing block marks as
+	 * we go.
+	 */
+	for (block = 0; block < block_count; block++) {
+		/*
+		 * Compute the chip, page and byte addresses for this block's
+		 * conventional mark.
+		 */
+		chipnr = block >> (chip->chip_shift - chip->phys_erase_shift);
+		page = block << (chip->phys_erase_shift - chip->page_shift);
+		byte = block <<  chip->phys_erase_shift;
+
+		/* Send the command to read the conventional block mark. */
+		nand_select_target(chip, chipnr);
+		ret = nand_read_page_op(chip, page, mtd->writesize, &block_mark,
+					1);
+		nand_deselect_target(chip);
+
+		if (ret)
+			continue;
+
+		/*
+		 * Check if the block is marked bad. If so, we need to mark it
+		 * again, but this time the result will be a mark in the
+		 * location where we transcribe block marks.
+		 */
+		if (block_mark != 0xff) {
+			dev_dbg(dev, "Transcribing mark in block %u\n", block);
+			ret = chip->legacy.block_markbad(chip, byte);
+			if (ret)
+				dev_err(dev,
+					"Failed to mark block bad with ret %d\n",
+					ret);
+		}
+	}
+
+	/* Write the stamp that indicates we've transcribed the block marks. */
+	mx23_write_transcription_stamp(this);
+	return 0;
+}
+
+static int nand_boot_init(struct gpmi_nand_data  *this)
+{
+	nand_boot_set_geometry(this);
+
+	/* This is ROM arch-specific initilization before the BBT scanning. */
+	if (GPMI_IS_MX23(this))
+		return mx23_boot_init(this);
+	return 0;
+}
+
+static int gpmi_set_geometry(struct gpmi_nand_data *this)
+{
+	int ret;
+
+	/* Free the temporary DMA memory for reading ID. */
+	gpmi_free_dma_buffer(this);
+
+	/* Set up the NFC geometry which is used by BCH. */
+	ret = bch_set_geometry(this);
+	if (ret) {
+		dev_err(this->dev, "Error setting BCH geometry : %d\n", ret);
+		return ret;
+	}
+
+	/* Alloc the new DMA buffers according to the pagesize and oobsize */
+	return gpmi_alloc_dma_buffer(this);
+}
+
+static int gpmi_init_last(struct gpmi_nand_data *this)
+{
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	struct bch_geometry *bch_geo = &this->bch_geometry;
+	int ret;
+
+	/* Set up the medium geometry */
+	ret = gpmi_set_geometry(this);
+	if (ret)
+		return ret;
+
+	/* Init the nand_ecc_ctrl{} */
+	ecc->read_page	= gpmi_ecc_read_page;
+	ecc->write_page	= gpmi_ecc_write_page;
+	ecc->read_oob	= gpmi_ecc_read_oob;
+	ecc->write_oob	= gpmi_ecc_write_oob;
+	ecc->read_page_raw = gpmi_ecc_read_page_raw;
+	ecc->write_page_raw = gpmi_ecc_write_page_raw;
+	ecc->read_oob_raw = gpmi_ecc_read_oob_raw;
+	ecc->write_oob_raw = gpmi_ecc_write_oob_raw;
+	ecc->engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
+	ecc->size	= bch_geo->ecc_chunk_size;
+	ecc->strength	= bch_geo->ecc_strength;
+	mtd_set_ooblayout(mtd, &gpmi_ooblayout_ops);
+
+	/*
+	 * We only enable the subpage read when:
+	 *  (1) the chip is imx6, and
+	 *  (2) the size of the ECC parity is byte aligned.
+	 */
+	if (GPMI_IS_MX6(this) &&
+		((bch_geo->gf_len * bch_geo->ecc_strength) % 8) == 0) {
+		ecc->read_subpage = gpmi_ecc_read_subpage;
+		chip->options |= NAND_SUBPAGE_READ;
+	}
+
+	return 0;
+}
+
+static int gpmi_nand_attach_chip(struct nand_chip *chip)
+{
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	int ret;
+
+	if (chip->bbt_options & NAND_BBT_USE_FLASH) {
+		chip->bbt_options |= NAND_BBT_NO_OOB;
+
+		if (of_property_read_bool(this->dev->of_node,
+					  "fsl,no-blockmark-swap"))
+			this->swap_block_mark = false;
+	}
+	dev_dbg(this->dev, "Blockmark swapping %sabled\n",
+		this->swap_block_mark ? "en" : "dis");
+
+	ret = gpmi_init_last(this);
+	if (ret)
+		return ret;
+
+	chip->options |= NAND_SKIP_BBTSCAN;
+
+	return 0;
+}
+
+static struct gpmi_transfer *get_next_transfer(struct gpmi_nand_data *this)
+{
+	struct gpmi_transfer *transfer = &this->transfers[this->ntransfers];
+
+	this->ntransfers++;
+
+	if (this->ntransfers == GPMI_MAX_TRANSFERS)
+		return NULL;
+
+	return transfer;
+}
+
+static struct dma_async_tx_descriptor *gpmi_chain_command(
+	struct gpmi_nand_data *this, u8 cmd, const u8 *addr, int naddr)
+{
+	struct dma_chan *channel = get_dma_chan(this);
+	struct dma_async_tx_descriptor *desc;
+	struct gpmi_transfer *transfer;
+	int chip = this->nand.cur_cs;
+	u32 pio[3];
+
+	/* [1] send out the PIO words */
+	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__WRITE)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(chip, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_CLE)
+		| BM_GPMI_CTRL0_ADDRESS_INCREMENT
+		| BF_GPMI_CTRL0_XFER_COUNT(naddr + 1);
+	pio[1] = 0;
+	pio[2] = 0;
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, 0);
+	if (!desc)
+		return NULL;
+
+	transfer = get_next_transfer(this);
+	if (!transfer)
+		return NULL;
+
+	transfer->cmdbuf[0] = cmd;
+	if (naddr)
+		memcpy(&transfer->cmdbuf[1], addr, naddr);
+
+	sg_init_one(&transfer->sgl, transfer->cmdbuf, naddr + 1);
+	dma_map_sg(this->dev, &transfer->sgl, 1, DMA_TO_DEVICE);
+
+	transfer->direction = DMA_TO_DEVICE;
+
+	desc = dmaengine_prep_slave_sg(channel, &transfer->sgl, 1, DMA_MEM_TO_DEV,
+				       MXS_DMA_CTRL_WAIT4END);
+	return desc;
+}
+
+static struct dma_async_tx_descriptor *gpmi_chain_wait_ready(
+	struct gpmi_nand_data *this)
+{
+	struct dma_chan *channel = get_dma_chan(this);
+	u32 pio[2];
+
+	pio[0] =  BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(this->nand.cur_cs, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_DATA)
+		| BF_GPMI_CTRL0_XFER_COUNT(0);
+	pio[1] = 0;
+
+	return mxs_dmaengine_prep_pio(channel, pio, 2, DMA_TRANS_NONE,
+				MXS_DMA_CTRL_WAIT4END | MXS_DMA_CTRL_WAIT4RDY);
+}
+
+static struct dma_async_tx_descriptor *gpmi_chain_data_read(
+	struct gpmi_nand_data *this, void *buf, int raw_len, bool *direct)
+{
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *channel = get_dma_chan(this);
+	struct gpmi_transfer *transfer;
+	u32 pio[6] = {};
+
+	transfer = get_next_transfer(this);
+	if (!transfer)
+		return NULL;
+
+	transfer->direction = DMA_FROM_DEVICE;
+
+	*direct = prepare_data_dma(this, buf, raw_len, &transfer->sgl,
+				   DMA_FROM_DEVICE);
+
+	pio[0] =  BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__READ)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(this->nand.cur_cs, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_DATA)
+		| BF_GPMI_CTRL0_XFER_COUNT(raw_len);
+
+	if (this->bch) {
+		pio[2] =  BM_GPMI_ECCCTRL_ENABLE_ECC
+			| BF_GPMI_ECCCTRL_ECC_CMD(BV_GPMI_ECCCTRL_ECC_CMD__BCH_DECODE)
+			| BF_GPMI_ECCCTRL_BUFFER_MASK(BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE
+				| BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY);
+		pio[3] = raw_len;
+		pio[4] = transfer->sgl.dma_address;
+		pio[5] = this->auxiliary_phys;
+	}
+
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, 0);
+	if (!desc)
+		return NULL;
+
+	if (!this->bch)
+		desc = dmaengine_prep_slave_sg(channel, &transfer->sgl, 1,
+					     DMA_DEV_TO_MEM,
+					     MXS_DMA_CTRL_WAIT4END);
+
+	return desc;
+}
+
+static struct dma_async_tx_descriptor *gpmi_chain_data_write(
+	struct gpmi_nand_data *this, const void *buf, int raw_len)
+{
+	struct dma_chan *channel = get_dma_chan(this);
+	struct dma_async_tx_descriptor *desc;
+	struct gpmi_transfer *transfer;
+	u32 pio[6] = {};
+
+	transfer = get_next_transfer(this);
+	if (!transfer)
+		return NULL;
+
+	transfer->direction = DMA_TO_DEVICE;
+
+	prepare_data_dma(this, buf, raw_len, &transfer->sgl, DMA_TO_DEVICE);
+
+	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__WRITE)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(this->nand.cur_cs, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_DATA)
+		| BF_GPMI_CTRL0_XFER_COUNT(raw_len);
+
+	if (this->bch) {
+		pio[2] = BM_GPMI_ECCCTRL_ENABLE_ECC
+			| BF_GPMI_ECCCTRL_ECC_CMD(BV_GPMI_ECCCTRL_ECC_CMD__BCH_ENCODE)
+			| BF_GPMI_ECCCTRL_BUFFER_MASK(BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE |
+					BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY);
+		pio[3] = raw_len;
+		pio[4] = transfer->sgl.dma_address;
+		pio[5] = this->auxiliary_phys;
+	}
+
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE,
+				      (this->bch ? MXS_DMA_CTRL_WAIT4END : 0));
+	if (!desc)
+		return NULL;
+
+	if (!this->bch)
+		desc = dmaengine_prep_slave_sg(channel, &transfer->sgl, 1,
+					       DMA_MEM_TO_DEV,
+					       MXS_DMA_CTRL_WAIT4END);
+
+	return desc;
+}
+
+static int gpmi_nfc_exec_op(struct nand_chip *chip,
+			     const struct nand_operation *op,
+			     bool check_only)
+{
+	const struct nand_op_instr *instr;
+	struct gpmi_nand_data *this = nand_get_controller_data(chip);
+	struct dma_async_tx_descriptor *desc = NULL;
+	int i, ret, buf_len = 0, nbufs = 0;
+	u8 cmd = 0;
+	void *buf_read = NULL;
+	const void *buf_write = NULL;
+	bool direct = false;
+	struct completion *dma_completion, *bch_completion;
+	unsigned long to;
+
+	if (check_only)
+		return 0;
+
+	this->ntransfers = 0;
+	for (i = 0; i < GPMI_MAX_TRANSFERS; i++)
+		this->transfers[i].direction = DMA_NONE;
+
+	ret = pm_runtime_get_sync(this->dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(this->dev);
+		return ret;
+	}
+
+	/*
+	 * This driver currently supports only one NAND chip. Plus, dies share
+	 * the same configuration. So once timings have been applied on the
+	 * controller side, they will not change anymore. When the time will
+	 * come, the check on must_apply_timings will have to be dropped.
+	 */
+	if (this->hw.must_apply_timings) {
+		this->hw.must_apply_timings = false;
+		ret = gpmi_nfc_apply_timings(this);
+		if (ret)
+			goto out_pm;
+	}
+
+	dev_dbg(this->dev, "%s: %d instructions\n", __func__, op->ninstrs);
+
+	for (i = 0; i < op->ninstrs; i++) {
+		instr = &op->instrs[i];
+
+		nand_op_trace("  ", instr);
+
+		switch (instr->type) {
+		case NAND_OP_WAITRDY_INSTR:
+			desc = gpmi_chain_wait_ready(this);
+			break;
+		case NAND_OP_CMD_INSTR:
+			cmd = instr->ctx.cmd.opcode;
+
+			/*
+			 * When this command has an address cycle chain it
+			 * together with the address cycle
+			 */
+			if (i + 1 != op->ninstrs &&
+			    op->instrs[i + 1].type == NAND_OP_ADDR_INSTR)
+				continue;
+
+			desc = gpmi_chain_command(this, cmd, NULL, 0);
+
+			break;
+		case NAND_OP_ADDR_INSTR:
+			desc = gpmi_chain_command(this, cmd, instr->ctx.addr.addrs,
+						  instr->ctx.addr.naddrs);
+			break;
+		case NAND_OP_DATA_OUT_INSTR:
+			buf_write = instr->ctx.data.buf.out;
+			buf_len = instr->ctx.data.len;
+			nbufs++;
+
+			desc = gpmi_chain_data_write(this, buf_write, buf_len);
+
+			break;
+		case NAND_OP_DATA_IN_INSTR:
+			if (!instr->ctx.data.len)
+				break;
+			buf_read = instr->ctx.data.buf.in;
+			buf_len = instr->ctx.data.len;
+			nbufs++;
+
+			desc = gpmi_chain_data_read(this, buf_read, buf_len,
+						   &direct);
+			break;
+		}
+
+		if (!desc) {
+			ret = -ENXIO;
+			goto unmap;
+		}
+	}
+
+	dev_dbg(this->dev, "%s setup done\n", __func__);
+
+	if (nbufs > 1) {
+		dev_err(this->dev, "Multiple data instructions not supported\n");
+		ret = -EINVAL;
+		goto unmap;
+	}
+
+	if (this->bch) {
+		writel(this->bch_flashlayout0,
+		       this->resources.bch_regs + HW_BCH_FLASH0LAYOUT0);
+		writel(this->bch_flashlayout1,
+		       this->resources.bch_regs + HW_BCH_FLASH0LAYOUT1);
+	}
+
+	desc->callback = dma_irq_callback;
+	desc->callback_param = this;
+	dma_completion = &this->dma_done;
+	bch_completion = NULL;
+
+	init_completion(dma_completion);
+
+	if (this->bch && buf_read) {
+		writel(BM_BCH_CTRL_COMPLETE_IRQ_EN,
+		       this->resources.bch_regs + HW_BCH_CTRL_SET);
+		bch_completion = &this->bch_done;
+		init_completion(bch_completion);
+	}
+
+	dmaengine_submit(desc);
+	dma_async_issue_pending(get_dma_chan(this));
+
+	to = wait_for_completion_timeout(dma_completion, msecs_to_jiffies(1000));
+	if (!to) {
+		dev_err(this->dev, "DMA timeout, last DMA\n");
+		gpmi_dump_info(this);
+		ret = -ETIMEDOUT;
+		goto unmap;
+	}
+
+	if (this->bch && buf_read) {
+		to = wait_for_completion_timeout(bch_completion, msecs_to_jiffies(1000));
+		if (!to) {
+			dev_err(this->dev, "BCH timeout, last DMA\n");
+			gpmi_dump_info(this);
+			ret = -ETIMEDOUT;
+			goto unmap;
+		}
+	}
+
+	writel(BM_BCH_CTRL_COMPLETE_IRQ_EN,
+	       this->resources.bch_regs + HW_BCH_CTRL_CLR);
+	gpmi_clear_bch(this);
+
+	ret = 0;
+
+unmap:
+	for (i = 0; i < this->ntransfers; i++) {
+		struct gpmi_transfer *transfer = &this->transfers[i];
+
+		if (transfer->direction != DMA_NONE)
+			dma_unmap_sg(this->dev, &transfer->sgl, 1,
+				     transfer->direction);
+	}
+
+	if (!ret && buf_read && !direct)
+		memcpy(buf_read, this->data_buffer_dma,
+		       gpmi_raw_len_to_len(this, buf_len));
+
+	this->bch = false;
+
+out_pm:
+	pm_runtime_mark_last_busy(this->dev);
+	pm_runtime_put_autosuspend(this->dev);
+
+	return ret;
+}
+
+static const struct nand_controller_ops gpmi_nand_controller_ops = {
+	.attach_chip = gpmi_nand_attach_chip,
+	.setup_interface = gpmi_setup_interface,
+	.exec_op = gpmi_nfc_exec_op,
+};
+
+static int gpmi_nand_init(struct gpmi_nand_data *this)
+{
+	struct nand_chip *chip = &this->nand;
+	struct mtd_info  *mtd = nand_to_mtd(chip);
+	int ret;
+
+	/* init the MTD data structures */
+	mtd->name		= "gpmi-nand";
+	mtd->dev.parent		= this->dev;
+
+	/* init the nand_chip{}, we don't support a 16-bit NAND Flash bus. */
+	nand_set_controller_data(chip, this);
+	nand_set_flash_node(chip, this->pdev->dev.of_node);
+	chip->legacy.block_markbad = gpmi_block_markbad;
+	chip->badblock_pattern	= &gpmi_bbt_descr;
+	chip->options		|= NAND_NO_SUBPAGE_WRITE;
+
+	/* Set up swap_block_mark, must be set before the gpmi_set_geometry() */
+	this->swap_block_mark = !GPMI_IS_MX23(this);
+
+	/*
+	 * Allocate a temporary DMA buffer for reading ID in the
+	 * nand_scan_ident().
+	 */
+	this->bch_geometry.payload_size = 1024;
+	this->bch_geometry.auxiliary_size = 128;
+	ret = gpmi_alloc_dma_buffer(this);
+	if (ret)
+		return ret;
+
+	nand_controller_init(&this->base);
+	this->base.ops = &gpmi_nand_controller_ops;
+	chip->controller = &this->base;
+
+	ret = nand_scan(chip, GPMI_IS_MX6(this) ? 2 : 1);
+	if (ret)
+		goto err_out;
+
+	ret = nand_boot_init(this);
+	if (ret)
+		goto err_nand_cleanup;
+	ret = nand_create_bbt(chip);
+	if (ret)
+		goto err_nand_cleanup;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret)
+		goto err_nand_cleanup;
+	return 0;
+
+err_nand_cleanup:
+	nand_cleanup(chip);
+err_out:
+	gpmi_free_dma_buffer(this);
+	return ret;
+}
+
+static const struct of_device_id gpmi_nand_id_table[] = {
+	{
+		.compatible = "fsl,imx23-gpmi-nand",
+		.data = &gpmi_devdata_imx23,
+	}, {
+		.compatible = "fsl,imx28-gpmi-nand",
+		.data = &gpmi_devdata_imx28,
+	}, {
+		.compatible = "fsl,imx6q-gpmi-nand",
+		.data = &gpmi_devdata_imx6q,
+	}, {
+		.compatible = "fsl,imx6sx-gpmi-nand",
+		.data = &gpmi_devdata_imx6sx,
+	}, {
+		.compatible = "fsl,imx7d-gpmi-nand",
+		.data = &gpmi_devdata_imx7d,
+	}, {}
+};
+MODULE_DEVICE_TABLE(of, gpmi_nand_id_table);
+
+static int gpmi_nand_probe(struct platform_device *pdev)
+{
+	struct gpmi_nand_data *this;
+	const struct of_device_id *of_id;
+	int ret;
+
+	this = devm_kzalloc(&pdev->dev, sizeof(*this), GFP_KERNEL);
+	if (!this)
+		return -ENOMEM;
+
+	of_id = of_match_device(gpmi_nand_id_table, &pdev->dev);
+	if (of_id) {
+		this->devdata = of_id->data;
+	} else {
+		dev_err(&pdev->dev, "Failed to find the right device id.\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, this);
+	this->pdev  = pdev;
+	this->dev   = &pdev->dev;
+
+	ret = acquire_resources(this);
+	if (ret)
+		goto exit_acquire_resources;
+
+	ret = __gpmi_enable_clk(this, true);
+	if (ret)
+		goto exit_acquire_resources;
+
+	pm_runtime_set_autosuspend_delay(&pdev->dev, 500);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	ret = gpmi_init(this);
+	if (ret)
+		goto exit_nfc_init;
+
+	ret = gpmi_nand_init(this);
+	if (ret)
+		goto exit_nfc_init;
+
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_put_autosuspend(&pdev->dev);
+
+	dev_info(this->dev, "driver registered.\n");
+
+	return 0;
+
+exit_nfc_init:
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	release_resources(this);
+exit_acquire_resources:
+
+	return ret;
+}
+
+static int gpmi_nand_remove(struct platform_device *pdev)
+{
+	struct gpmi_nand_data *this = platform_get_drvdata(pdev);
+	struct nand_chip *chip = &this->nand;
+	int ret;
+
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	ret = mtd_device_unregister(nand_to_mtd(chip));
+	WARN_ON(ret);
+	nand_cleanup(chip);
+	gpmi_free_dma_buffer(this);
+	release_resources(this);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int gpmi_pm_suspend(struct device *dev)
+{
+	struct gpmi_nand_data *this = dev_get_drvdata(dev);
+
+	release_dma_channels(this);
+	return 0;
+}
+
+static int gpmi_pm_resume(struct device *dev)
+{
+	struct gpmi_nand_data *this = dev_get_drvdata(dev);
+	int ret;
+
+	ret = acquire_dma_channels(this);
+	if (ret < 0)
+		return ret;
+
+	/* re-init the GPMI registers */
+	ret = gpmi_init(this);
+	if (ret) {
+		dev_err(this->dev, "Error setting GPMI : %d\n", ret);
+		return ret;
+	}
+
+	/* Set flag to get timing setup restored for next exec_op */
+	if (this->hw.clk_rate)
+		this->hw.must_apply_timings = true;
+
+	/* re-init the BCH registers */
+	ret = bch_set_geometry(this);
+	if (ret) {
+		dev_err(this->dev, "Error setting BCH : %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static int __maybe_unused gpmi_runtime_suspend(struct device *dev)
+{
+	struct gpmi_nand_data *this = dev_get_drvdata(dev);
+
+	return __gpmi_enable_clk(this, false);
+}
+
+static int __maybe_unused gpmi_runtime_resume(struct device *dev)
+{
+	struct gpmi_nand_data *this = dev_get_drvdata(dev);
+
+	return __gpmi_enable_clk(this, true);
+}
+
+static const struct dev_pm_ops gpmi_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(gpmi_pm_suspend, gpmi_pm_resume)
+	SET_RUNTIME_PM_OPS(gpmi_runtime_suspend, gpmi_runtime_resume, NULL)
+};
+
+static struct platform_driver gpmi_nand_driver = {
+	.driver = {
+		.name = "gpmi-nand",
+		.pm = &gpmi_pm_ops,
+		.of_match_table = gpmi_nand_id_table,
+	},
+	.probe   = gpmi_nand_probe,
+	.remove  = gpmi_nand_remove,
+};
+module_platform_driver(gpmi_nand_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("i.MX GPMI NAND Flash Controller Driver");
+MODULE_LICENSE("GPL");