[PATCH 03/14] mtd: rawnand: gpmi: move all driver code into single file

Sascha Hauer s.hauer at pengutronix.de
Tue Apr 9 04:34:10 PDT 2019


This moves the whole driver into a single C file. The filename gpmi-lib
implies that it implements library functions, but in fact there are
several cases where functions in gpmi-lib.c call back into functions in
gpmi-nand.c. With this one has to constantly jump between those two
files, so moving it into a single file improves readability, even when
the file gets quite large.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/mtd/nand/raw/gpmi-nand/Makefile    |    1 -
 drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c  |  936 --------------
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 1272 +++++++++++++++++---
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h |   34 -
 4 files changed, 1098 insertions(+), 1145 deletions(-)
 delete mode 100644 drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c

diff --git a/drivers/mtd/nand/raw/gpmi-nand/Makefile b/drivers/mtd/nand/raw/gpmi-nand/Makefile
index 3a462487c35e..60c7b6f87c53 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/Makefile
+++ b/drivers/mtd/nand/raw/gpmi-nand/Makefile
@@ -1,3 +1,2 @@
 obj-$(CONFIG_MTD_NAND_GPMI_NAND) += gpmi_nand.o
 gpmi_nand-objs += gpmi-nand.o
-gpmi_nand-objs += gpmi-lib.o
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c
deleted file mode 100644
index a4768df5083f..000000000000
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-lib.c
+++ /dev/null
@@ -1,936 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Freescale GPMI NAND Flash Driver
- *
- * Copyright (C) 2008-2011 Freescale Semiconductor, Inc.
- * Copyright (C) 2008 Embedded Alley Solutions, Inc.
- */
-#include <linux/delay.h>
-#include <linux/clk.h>
-#include <linux/slab.h>
-
-#include "gpmi-nand.h"
-#include "gpmi-regs.h"
-#include "bch-regs.h"
-
-/* 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;
-}
-
-int gpmi_enable_clk(struct gpmi_nand_data *this)
-{
-	return __gpmi_enable_clk(this, true);
-}
-
-int gpmi_disable_clk(struct gpmi_nand_data *this)
-{
-	return __gpmi_enable_clk(this, false);
-}
-
-int gpmi_init(struct gpmi_nand_data *this)
-{
-	struct resources *r = &this->resources;
-	int ret;
-
-	ret = gpmi_enable_clk(this);
-	if (ret)
-		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_MX23(this) || GPMI_IS_MX28(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);
-
-	gpmi_disable_clk(this);
-	return 0;
-err_out:
-	gpmi_disable_clk(this);
-	return ret;
-}
-
-/* This function is very useful. It is called only when the bug occur. */
-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);
-}
-
-/* Configures the geometry for BCH.  */
-int bch_set_geometry(struct gpmi_nand_data *this)
-{
-	struct resources *r = &this->resources;
-	struct bch_geometry *bch_geo = &this->bch_geometry;
-	unsigned int block_count;
-	unsigned int block_size;
-	unsigned int metadata_size;
-	unsigned int ecc_strength;
-	unsigned int page_size;
-	unsigned int gf_len;
-	int ret;
-
-	ret = common_nfc_set_geometry(this);
-	if (ret)
-		return ret;
-
-	block_count   = bch_geo->ecc_chunk_count - 1;
-	block_size    = bch_geo->ecc_chunk_size;
-	metadata_size = bch_geo->metadata_size;
-	ecc_strength  = bch_geo->ecc_strength >> 1;
-	page_size     = bch_geo->page_size;
-	gf_len        = bch_geo->gf_len;
-
-	ret = gpmi_enable_clk(this);
-	if (ret)
-		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_MX23(this) || GPMI_IS_MX28(this));
-	if (ret)
-		goto err_out;
-
-	/* Configure layout 0. */
-	writel(BF_BCH_FLASH0LAYOUT0_NBLOCKS(block_count)
-			| BF_BCH_FLASH0LAYOUT0_META_SIZE(metadata_size)
-			| BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this)
-			| BF_BCH_FLASH0LAYOUT0_GF(gf_len, this)
-			| BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(block_size, this),
-			r->bch_regs + HW_BCH_FLASH0LAYOUT0);
-
-	writel(BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size)
-			| BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this)
-			| BF_BCH_FLASH0LAYOUT1_GF(gf_len, this)
-			| BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(block_size, this),
-			r->bch_regs + HW_BCH_FLASH0LAYOUT1);
-
-	/* Set *all* chip selects to use layout 0. */
-	writel(0, r->bch_regs + HW_BCH_LAYOUTSELECT);
-
-	/* Enable interrupts. */
-	writel(BM_BCH_CTRL_COMPLETE_IRQ_EN,
-				r->bch_regs + HW_BCH_CTRL_SET);
-
-	gpmi_disable_clk(this);
-	return 0;
-err_out:
-	gpmi_disable_clk(this);
-	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;
-	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;
-	u16 busy_timeout_cycles;
-	u8 wrn_dly_sel;
-
-	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;
-	}
-
-	/* 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_cycles = TO_CYCLES(sdr->tWB_max + sdr->tR_max, 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);
-}
-
-void 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;
-
-	clk_set_rate(r->clock[0], hw->clk_rate);
-
-	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);
-}
-
-int gpmi_setup_data_interface(struct nand_chip *chip, int chipnr,
-			      const struct nand_data_interface *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. */
-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);
-}
-
-/* Returns the Ready/Busy status of the given chip. */
-int gpmi_is_ready(struct gpmi_nand_data *this, unsigned chip)
-{
-	struct resources *r = &this->resources;
-	uint32_t mask = 0;
-	uint32_t reg = 0;
-
-	if (GPMI_IS_MX23(this)) {
-		mask = MX23_BM_GPMI_DEBUG_READY0 << chip;
-		reg = readl(r->gpmi_regs + HW_GPMI_DEBUG);
-	} else if (GPMI_IS_MX28(this) || GPMI_IS_MX6(this)) {
-		/*
-		 * In the imx6, all the ready/busy pins are bound
-		 * together. So we only need to check chip 0.
-		 */
-		if (GPMI_IS_MX6(this))
-			chip = 0;
-
-		/* MX28 shares the same R/B register as MX6Q. */
-		mask = MX28_BF_GPMI_STAT_READY_BUSY(1 << chip);
-		reg = readl(r->gpmi_regs + HW_GPMI_STAT);
-	} else
-		dev_err(this->dev, "unknown arch.\n");
-	return reg & mask;
-}
-
-int gpmi_send_command(struct gpmi_nand_data *this)
-{
-	struct dma_chan *channel = get_dma_chan(this);
-	struct dma_async_tx_descriptor *desc;
-	struct scatterlist *sgl;
-	int chip = this->current_chip;
-	int ret;
-	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(this->command_length);
-	pio[1] = pio[2] = 0;
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
-	if (!desc)
-		return -EINVAL;
-
-	/* [2] send out the COMMAND + ADDRESS string stored in @buffer */
-	sgl = &this->cmd_sgl;
-
-	sg_init_one(sgl, this->cmd_buffer, this->command_length);
-	dma_map_sg(this->dev, sgl, 1, DMA_TO_DEVICE);
-	desc = dmaengine_prep_slave_sg(channel,
-				sgl, 1, DMA_MEM_TO_DEV,
-				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-	if (!desc)
-		return -EINVAL;
-
-	/* [3] submit the DMA */
-	ret = start_dma_without_bch_irq(this, desc);
-
-	dma_unmap_sg(this->dev, sgl, 1, DMA_TO_DEVICE);
-
-	return ret;
-}
-
-int gpmi_send_data(struct gpmi_nand_data *this, const void *buf, int len)
-{
-	struct dma_async_tx_descriptor *desc;
-	struct dma_chan *channel = get_dma_chan(this);
-	int chip = this->current_chip;
-	int ret;
-	uint32_t command_mode;
-	uint32_t address;
-	u32 pio[2];
-
-	/* [1] PIO */
-	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WRITE;
-	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
-
-	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
-		| BM_GPMI_CTRL0_WORD_LENGTH
-		| BF_GPMI_CTRL0_CS(chip, this)
-		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
-		| BF_GPMI_CTRL0_ADDRESS(address)
-		| BF_GPMI_CTRL0_XFER_COUNT(len);
-	pio[1] = 0;
-	desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
-	if (!desc)
-		return -EINVAL;
-
-	/* [2] send DMA request */
-	prepare_data_dma(this, buf, len, DMA_TO_DEVICE);
-	desc = dmaengine_prep_slave_sg(channel, &this->data_sgl,
-					1, DMA_MEM_TO_DEV,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-	if (!desc)
-		return -EINVAL;
-
-	/* [3] submit the DMA */
-	ret = start_dma_without_bch_irq(this, desc);
-
-	dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_TO_DEVICE);
-
-	return ret;
-}
-
-int gpmi_read_data(struct gpmi_nand_data *this, void *buf, int len)
-{
-	struct dma_async_tx_descriptor *desc;
-	struct dma_chan *channel = get_dma_chan(this);
-	int chip = this->current_chip;
-	int ret;
-	u32 pio[2];
-	bool direct;
-
-	/* [1] : send PIO */
-	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__READ)
-		| 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_DATA)
-		| BF_GPMI_CTRL0_XFER_COUNT(len);
-	pio[1] = 0;
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
-	if (!desc)
-		return -EINVAL;
-
-	/* [2] : send DMA request */
-	direct = prepare_data_dma(this, buf, len, DMA_FROM_DEVICE);
-	desc = dmaengine_prep_slave_sg(channel, &this->data_sgl,
-					1, DMA_DEV_TO_MEM,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-	if (!desc)
-		return -EINVAL;
-
-	/* [3] : submit the DMA */
-
-	ret = start_dma_without_bch_irq(this, desc);
-
-	dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_FROM_DEVICE);
-	if (!direct)
-		memcpy(buf, this->data_buffer_dma, len);
-
-	return ret;
-}
-
-int gpmi_send_page(struct gpmi_nand_data *this,
-			dma_addr_t payload, dma_addr_t auxiliary)
-{
-	struct bch_geometry *geo = &this->bch_geometry;
-	uint32_t command_mode;
-	uint32_t address;
-	uint32_t ecc_command;
-	uint32_t buffer_mask;
-	struct dma_async_tx_descriptor *desc;
-	struct dma_chan *channel = get_dma_chan(this);
-	int chip = this->current_chip;
-	u32 pio[6];
-
-	/* A DMA descriptor that does an ECC page read. */
-	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WRITE;
-	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
-	ecc_command  = BV_GPMI_ECCCTRL_ECC_CMD__BCH_ENCODE;
-	buffer_mask  = BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE |
-				BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY;
-
-	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
-		| BM_GPMI_CTRL0_WORD_LENGTH
-		| BF_GPMI_CTRL0_CS(chip, this)
-		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
-		| BF_GPMI_CTRL0_ADDRESS(address)
-		| BF_GPMI_CTRL0_XFER_COUNT(0);
-	pio[1] = 0;
-	pio[2] = BM_GPMI_ECCCTRL_ENABLE_ECC
-		| BF_GPMI_ECCCTRL_ECC_CMD(ecc_command)
-		| BF_GPMI_ECCCTRL_BUFFER_MASK(buffer_mask);
-	pio[3] = geo->page_size;
-	pio[4] = payload;
-	pio[5] = auxiliary;
-
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE,
-					DMA_CTRL_ACK);
-	if (!desc)
-		return -EINVAL;
-
-	return start_dma_with_bch_irq(this, desc);
-}
-
-int gpmi_read_page(struct gpmi_nand_data *this,
-				dma_addr_t payload, dma_addr_t auxiliary)
-{
-	struct bch_geometry *geo = &this->bch_geometry;
-	uint32_t command_mode;
-	uint32_t address;
-	uint32_t ecc_command;
-	uint32_t buffer_mask;
-	struct dma_async_tx_descriptor *desc;
-	struct dma_chan *channel = get_dma_chan(this);
-	int chip = this->current_chip;
-	u32 pio[6];
-
-	/* [1] Wait for the chip to report ready. */
-	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY;
-	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
-
-	pio[0] =  BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
-		| BM_GPMI_CTRL0_WORD_LENGTH
-		| BF_GPMI_CTRL0_CS(chip, this)
-		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
-		| BF_GPMI_CTRL0_ADDRESS(address)
-		| BF_GPMI_CTRL0_XFER_COUNT(0);
-	pio[1] = 0;
-	desc = dmaengine_prep_slave_sg(channel,
-				(struct scatterlist *)pio, 2,
-				DMA_TRANS_NONE, 0);
-	if (!desc)
-		return -EINVAL;
-
-	/* [2] Enable the BCH block and read. */
-	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__READ;
-	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
-	ecc_command  = BV_GPMI_ECCCTRL_ECC_CMD__BCH_DECODE;
-	buffer_mask  = BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE
-			| BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY;
-
-	pio[0] =  BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
-		| BM_GPMI_CTRL0_WORD_LENGTH
-		| BF_GPMI_CTRL0_CS(chip, this)
-		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
-		| BF_GPMI_CTRL0_ADDRESS(address)
-		| BF_GPMI_CTRL0_XFER_COUNT(geo->page_size);
-
-	pio[1] = 0;
-	pio[2] =  BM_GPMI_ECCCTRL_ENABLE_ECC
-		| BF_GPMI_ECCCTRL_ECC_CMD(ecc_command)
-		| BF_GPMI_ECCCTRL_BUFFER_MASK(buffer_mask);
-	pio[3] = geo->page_size;
-	pio[4] = payload;
-	pio[5] = auxiliary;
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE,
-					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-	if (!desc)
-		return -EINVAL;
-
-	/* [3] Disable the BCH block */
-	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY;
-	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
-
-	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
-		| BM_GPMI_CTRL0_WORD_LENGTH
-		| BF_GPMI_CTRL0_CS(chip, this)
-		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
-		| BF_GPMI_CTRL0_ADDRESS(address)
-		| BF_GPMI_CTRL0_XFER_COUNT(geo->page_size);
-	pio[1] = 0;
-	pio[2] = 0; /* clear GPMI_HW_GPMI_ECCCTRL, disable the BCH. */
-	desc = dmaengine_prep_slave_sg(channel,
-				(struct scatterlist *)pio, 3,
-				DMA_TRANS_NONE,
-				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-	if (!desc)
-		return -EINVAL;
-
-	/* [4] submit the DMA */
-	return start_dma_with_bch_irq(this, desc);
-}
-
-/**
- * gpmi_copy_bits - copy bits from one memory region to another
- * @dst: destination buffer
- * @dst_bit_off: bit offset we're starting to write at
- * @src: source buffer
- * @src_bit_off: bit offset we're starting to read from
- * @nbits: number of bits to copy
- *
- * This functions copies bits from one memory region to another, and is used by
- * the GPMI driver to copy ECC sections which are not guaranteed to be byte
- * aligned.
- *
- * src and dst should not overlap.
- *
- */
-void gpmi_copy_bits(u8 *dst, size_t dst_bit_off,
-		    const u8 *src, size_t src_bit_off,
-		    size_t nbits)
-{
-	size_t i;
-	size_t nbytes;
-	u32 src_buffer = 0;
-	size_t bits_in_src_buffer = 0;
-
-	if (!nbits)
-		return;
-
-	/*
-	 * Move src and dst pointers to the closest byte pointer and store bit
-	 * offsets within a byte.
-	 */
-	src += src_bit_off / 8;
-	src_bit_off %= 8;
-
-	dst += dst_bit_off / 8;
-	dst_bit_off %= 8;
-
-	/*
-	 * Initialize the src_buffer value with bits available in the first
-	 * byte of data so that we end up with a byte aligned src pointer.
-	 */
-	if (src_bit_off) {
-		src_buffer = src[0] >> src_bit_off;
-		if (nbits >= (8 - src_bit_off)) {
-			bits_in_src_buffer += 8 - src_bit_off;
-		} else {
-			src_buffer &= GENMASK(nbits - 1, 0);
-			bits_in_src_buffer += nbits;
-		}
-		nbits -= bits_in_src_buffer;
-		src++;
-	}
-
-	/* Calculate the number of bytes that can be copied from src to dst. */
-	nbytes = nbits / 8;
-
-	/* Try to align dst to a byte boundary. */
-	if (dst_bit_off) {
-		if (bits_in_src_buffer < (8 - dst_bit_off) && nbytes) {
-			src_buffer |= src[0] << bits_in_src_buffer;
-			bits_in_src_buffer += 8;
-			src++;
-			nbytes--;
-		}
-
-		if (bits_in_src_buffer >= (8 - dst_bit_off)) {
-			dst[0] &= GENMASK(dst_bit_off - 1, 0);
-			dst[0] |= src_buffer << dst_bit_off;
-			src_buffer >>= (8 - dst_bit_off);
-			bits_in_src_buffer -= (8 - dst_bit_off);
-			dst_bit_off = 0;
-			dst++;
-			if (bits_in_src_buffer > 7) {
-				bits_in_src_buffer -= 8;
-				dst[0] = src_buffer;
-				dst++;
-				src_buffer >>= 8;
-			}
-		}
-	}
-
-	if (!bits_in_src_buffer && !dst_bit_off) {
-		/*
-		 * Both src and dst pointers are byte aligned, thus we can
-		 * just use the optimized memcpy function.
-		 */
-		if (nbytes)
-			memcpy(dst, src, nbytes);
-	} else {
-		/*
-		 * src buffer is not byte aligned, hence we have to copy each
-		 * src byte to the src_buffer variable before extracting a byte
-		 * to store in dst.
-		 */
-		for (i = 0; i < nbytes; i++) {
-			src_buffer |= src[i] << bits_in_src_buffer;
-			dst[i] = src_buffer;
-			src_buffer >>= 8;
-		}
-	}
-	/* Update dst and src pointers */
-	dst += nbytes;
-	src += nbytes;
-
-	/*
-	 * nbits is the number of remaining bits. It should not exceed 8 as
-	 * we've already copied as much bytes as possible.
-	 */
-	nbits %= 8;
-
-	/*
-	 * If there's no more bits to copy to the destination and src buffer
-	 * was already byte aligned, then we're done.
-	 */
-	if (!nbits && !bits_in_src_buffer)
-		return;
-
-	/* Copy the remaining bits to src_buffer */
-	if (nbits)
-		src_buffer |= (*src & GENMASK(nbits - 1, 0)) <<
-			      bits_in_src_buffer;
-	bits_in_src_buffer += nbits;
-
-	/*
-	 * In case there were not enough bits to get a byte aligned dst buffer
-	 * prepare the src_buffer variable to match the dst organization (shift
-	 * src_buffer by dst_bit_off and retrieve the least significant bits
-	 * from dst).
-	 */
-	if (dst_bit_off)
-		src_buffer = (src_buffer << dst_bit_off) |
-			     (*dst & GENMASK(dst_bit_off - 1, 0));
-	bits_in_src_buffer += dst_bit_off;
-
-	/*
-	 * Keep most significant bits from dst if we end up with an unaligned
-	 * number of bits.
-	 */
-	nbytes = bits_in_src_buffer / 8;
-	if (bits_in_src_buffer % 8) {
-		src_buffer |= (dst[nbytes] &
-			       GENMASK(7, bits_in_src_buffer % 8)) <<
-			      (nbytes * 8);
-		nbytes++;
-	}
-
-	/* Copy the remaining bytes to dst */
-	for (i = 0; i < nbytes; i++) {
-		dst[i] = src_buffer;
-		src_buffer >>= 8;
-	}
-}
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index ed405c9434fe..86927f02d234 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -6,6 +6,7 @@
  * 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>
@@ -14,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include "gpmi-nand.h"
+#include "gpmi-regs.h"
 #include "bch-regs.h"
 
 /* Resource names for the GPMI NAND driver. */
@@ -21,149 +23,224 @@
 #define GPMI_NAND_BCH_REGS_ADDR_RES_NAME   "bch"
 #define GPMI_NAND_BCH_INTERRUPT_RES_NAME   "bch"
 
-/* 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
-};
+/* 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
 /*
- * We may change the layout if we can get the ECC info from the datasheet,
- * else we will use all the (page + OOB).
+ * 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 gpmi_ooblayout_ecc(struct mtd_info *mtd, int section,
-			      struct mtd_oob_region *oobregion)
+static int clear_poll_bit(void __iomem *addr, u32 mask)
 {
-	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;
+	int timeout = 0x400;
 
-	if (section)
-		return -ERANGE;
+	/* clear the bit */
+	writel(mask, addr + MXS_CLR_ADDR);
 
-	oobregion->offset = 0;
-	oobregion->length = geo->page_size - mtd->writesize;
+	/*
+	 * 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_ooblayout_free(struct mtd_info *mtd, int section,
-			       struct mtd_oob_region *oobregion)
+static int __gpmi_enable_clk(struct gpmi_nand_data *this, bool v)
 {
-	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;
+	struct clk *clk;
+	int ret;
+	int i;
 
-	if (section)
-		return -ERANGE;
+	for (i = 0; i < GPMI_CLK_MAX; i++) {
+		clk = this->resources.clock[i];
+		if (!clk)
+			break;
 
-	/* 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;
+		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 const char * const gpmi_clks_for_mx2x[] = {
-	"gpmi_io",
-};
+static int gpmi_enable_clk(struct gpmi_nand_data *this)
+{
+	return __gpmi_enable_clk(this, true);
+}
 
-static const struct mtd_ooblayout_ops gpmi_ooblayout_ops = {
-	.ecc = gpmi_ooblayout_ecc,
-	.free = gpmi_ooblayout_free,
-};
+static int gpmi_disable_clk(struct gpmi_nand_data *this)
+{
+	return __gpmi_enable_clk(this, false);
+}
 
-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 int gpmi_init(struct gpmi_nand_data *this)
+{
+	struct resources *r = &this->resources;
+	int ret;
 
-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),
-};
+	ret = gpmi_enable_clk(this);
+	if (ret)
+		return ret;
+	ret = gpmi_reset_block(r->gpmi_regs, false);
+	if (ret)
+		goto err_out;
 
-static const char * const gpmi_clks_for_mx6[] = {
-	"gpmi_io", "gpmi_apb", "gpmi_bch", "gpmi_bch_apb", "per1_bch",
-};
+	/*
+	 * 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_MX23(this) || GPMI_IS_MX28(this));
+	if (ret)
+		goto err_out;
 
-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),
-};
+	/* Choose NAND mode. */
+	writel(BM_GPMI_CTRL1_GPMI_MODE, r->gpmi_regs + HW_GPMI_CTRL1_CLR);
 
-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),
-};
+	/* Set the IRQ polarity. */
+	writel(BM_GPMI_CTRL1_ATA_IRQRDY_POLARITY,
+				r->gpmi_regs + HW_GPMI_CTRL1_SET);
 
-static const char * const gpmi_clks_for_mx7d[] = {
-	"gpmi_io", "gpmi_bch_apb",
-};
+	/* Disable Write-Protection. */
+	writel(BM_GPMI_CTRL1_DEV_RESET, r->gpmi_regs + HW_GPMI_CTRL1_SET);
 
-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),
-};
+	/* Select BCH ECC. */
+	writel(BM_GPMI_CTRL1_BCH_MODE, r->gpmi_regs + HW_GPMI_CTRL1_SET);
 
-static irqreturn_t bch_irq(int irq, void *cookie)
-{
-	struct gpmi_nand_data *this = cookie;
+	/*
+	 * 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);
 
-	gpmi_clear_bch(this);
-	complete(&this->bch_done);
-	return IRQ_HANDLED;
+	gpmi_disable_clk(this);
+	return 0;
+err_out:
+	gpmi_disable_clk(this);
+	return ret;
 }
 
-/*
- *  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)
+/* 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;
-	struct mtd_info	*mtd = nand_to_mtd(&this->nand);
-	int ecc_strength;
+	u32 reg;
+	int i;
 
-	ecc_strength = ((mtd->oobsize - geo->metadata_size) * 8)
-			/ (geo->gf_len * geo->ecc_chunk_count);
+	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);
+	}
 
-	/* We need the minor even number. */
-	return round_down(ecc_strength, 2);
+	/* 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)
@@ -295,6 +372,37 @@ static int set_geometry_by_ecc_info(struct gpmi_nand_data *this,
 	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;
@@ -407,7 +515,7 @@ static int legacy_set_geometry(struct gpmi_nand_data *this)
 	return 0;
 }
 
-int common_nfc_set_geometry(struct gpmi_nand_data *this)
+static int common_nfc_set_geometry(struct gpmi_nand_data *this)
 {
 	struct nand_chip *chip = &this->nand;
 
@@ -427,84 +535,361 @@ int common_nfc_set_geometry(struct gpmi_nand_data *this)
 	return 0;
 }
 
-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];
-}
-
-/* Can we use the upper's buffer directly for DMA? */
-bool prepare_data_dma(struct gpmi_nand_data *this, const void *buf, int len,
-		      enum dma_data_direction dr)
+/* Configures the geometry for BCH.  */
+static int bch_set_geometry(struct gpmi_nand_data *this)
 {
-	struct scatterlist *sgl = &this->data_sgl;
+	struct resources *r = &this->resources;
+	struct bch_geometry *bch_geo = &this->bch_geometry;
+	unsigned int block_count;
+	unsigned int block_size;
+	unsigned int metadata_size;
+	unsigned int ecc_strength;
+	unsigned int page_size;
+	unsigned int gf_len;
 	int ret;
 
-	/* 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)
-		memcpy(this->data_buffer_dma, buf, len);
+	ret = common_nfc_set_geometry(this);
+	if (ret)
+		return ret;
 
-	dma_map_sg(this->dev, sgl, 1, dr);
+	block_count   = bch_geo->ecc_chunk_count - 1;
+	block_size    = bch_geo->ecc_chunk_size;
+	metadata_size = bch_geo->metadata_size;
+	ecc_strength  = bch_geo->ecc_strength >> 1;
+	page_size     = bch_geo->page_size;
+	gf_len        = bch_geo->gf_len;
 
-	return false;
-}
+	ret = gpmi_enable_clk(this);
+	if (ret)
+		return ret;
 
-/* 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;
+	/*
+	* 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_MX23(this) || GPMI_IS_MX28(this));
+	if (ret)
+		goto err_out;
 
-	complete(dma_c);
-}
+	/* Configure layout 0. */
+	writel(BF_BCH_FLASH0LAYOUT0_NBLOCKS(block_count)
+			| BF_BCH_FLASH0LAYOUT0_META_SIZE(metadata_size)
+			| BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this)
+			| BF_BCH_FLASH0LAYOUT0_GF(gf_len, this)
+			| BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(block_size, this),
+			r->bch_regs + HW_BCH_FLASH0LAYOUT0);
 
-int start_dma_without_bch_irq(struct gpmi_nand_data *this,
-				struct dma_async_tx_descriptor *desc)
-{
-	struct completion *dma_c = &this->dma_done;
-	unsigned long timeout;
+	writel(BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size)
+			| BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this)
+			| BF_BCH_FLASH0LAYOUT1_GF(gf_len, this)
+			| BF_BCH_FLASH0LAYOUT1_DATAN_SIZE(block_size, this),
+			r->bch_regs + HW_BCH_FLASH0LAYOUT1);
 
-	init_completion(dma_c);
+	/* Set *all* chip selects to use layout 0. */
+	writel(0, r->bch_regs + HW_BCH_LAYOUTSELECT);
 
-	desc->callback		= dma_irq_callback;
-	desc->callback_param	= this;
-	dmaengine_submit(desc);
-	dma_async_issue_pending(get_dma_chan(this));
+	/* Enable interrupts. */
+	writel(BM_BCH_CTRL_COMPLETE_IRQ_EN,
+				r->bch_regs + HW_BCH_CTRL_SET);
 
-	/* Wait for the interrupt from the DMA block. */
-	timeout = wait_for_completion_timeout(dma_c, msecs_to_jiffies(1000));
-	if (!timeout) {
-		dev_err(this->dev, "DMA timeout, last DMA\n");
-		gpmi_dump_info(this);
-		return -ETIMEDOUT;
-	}
+	gpmi_disable_clk(this);
 	return 0;
+err_out:
+	gpmi_disable_clk(this);
+	return ret;
 }
 
 /*
- * This function is used in BCH reading or BCH writing pages.
- * It will wait for the BCH interrupt as long as ONE second.
- * Actually, we must wait for two interrupts :
- *	[1] firstly the DMA interrupt and
- *	[2] secondly the BCH interrupt.
- */
-int start_dma_with_bch_irq(struct gpmi_nand_data *this,
-			struct dma_async_tx_descriptor *desc)
-{
-	struct completion *bch_c = &this->bch_done;
+ * <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;
+	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;
+	u16 busy_timeout_cycles;
+	u8 wrn_dly_sel;
+
+	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;
+	}
+
+	/* 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_cycles = TO_CYCLES(sdr->tWB_max + sdr->tR_max, 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 void 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;
+
+	clk_set_rate(r->clock[0], hw->clk_rate);
+
+	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);
+}
+
+static int gpmi_setup_data_interface(struct nand_chip *chip, int chipnr,
+				     const struct nand_data_interface *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);
+}
+
+/* Returns the Ready/Busy status of the given chip. */
+static int gpmi_is_ready(struct gpmi_nand_data *this, unsigned chip)
+{
+	struct resources *r = &this->resources;
+	uint32_t mask = 0;
+	uint32_t reg = 0;
+
+	if (GPMI_IS_MX23(this)) {
+		mask = MX23_BM_GPMI_DEBUG_READY0 << chip;
+		reg = readl(r->gpmi_regs + HW_GPMI_DEBUG);
+	} else if (GPMI_IS_MX28(this) || GPMI_IS_MX6(this)) {
+		/*
+		 * In the imx6, all the ready/busy pins are bound
+		 * together. So we only need to check chip 0.
+		 */
+		if (GPMI_IS_MX6(this))
+			chip = 0;
+
+		/* MX28 shares the same R/B register as MX6Q. */
+		mask = MX28_BF_GPMI_STAT_READY_BUSY(1 << chip);
+		reg = readl(r->gpmi_regs + HW_GPMI_STAT);
+	} else
+		dev_err(this->dev, "unknown arch.\n");
+	return reg & mask;
+}
+
+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 int start_dma_without_bch_irq(struct gpmi_nand_data *this,
+				     struct dma_async_tx_descriptor *desc)
+{
+	struct completion *dma_c = &this->dma_done;
+	unsigned long timeout;
+
+	init_completion(dma_c);
+
+	desc->callback		= dma_irq_callback;
+	desc->callback_param	= this;
+	dmaengine_submit(desc);
+	dma_async_issue_pending(get_dma_chan(this));
+
+	/* Wait for the interrupt from the DMA block. */
+	timeout = wait_for_completion_timeout(dma_c, msecs_to_jiffies(1000));
+	if (!timeout) {
+		dev_err(this->dev, "DMA timeout, last DMA\n");
+		gpmi_dump_info(this);
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+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;
+}
+
+/*
+ * This function is used in BCH reading or BCH writing pages.
+ * It will wait for the BCH interrupt as long as ONE second.
+ * Actually, we must wait for two interrupts :
+ *	[1] firstly the DMA interrupt and
+ *	[2] secondly the BCH interrupt.
+ */
+static int start_dma_with_bch_irq(struct gpmi_nand_data *this,
+				  struct dma_async_tx_descriptor *desc)
+{
+	struct completion *bch_c = &this->bch_done;
 	unsigned long timeout;
 
 	/* Prepare to receive an interrupt from the BCH block. */
@@ -523,6 +908,545 @@ int start_dma_with_bch_irq(struct gpmi_nand_data *this,
 	return 0;
 }
 
+static int gpmi_send_command(struct gpmi_nand_data *this)
+{
+	struct dma_chan *channel = get_dma_chan(this);
+	struct dma_async_tx_descriptor *desc;
+	struct scatterlist *sgl;
+	int chip = this->current_chip;
+	int ret;
+	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(this->command_length);
+	pio[1] = pio[2] = 0;
+	desc = dmaengine_prep_slave_sg(channel,
+					(struct scatterlist *)pio,
+					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+	if (!desc)
+		return -EINVAL;
+
+	/* [2] send out the COMMAND + ADDRESS string stored in @buffer */
+	sgl = &this->cmd_sgl;
+
+	sg_init_one(sgl, this->cmd_buffer, this->command_length);
+	dma_map_sg(this->dev, sgl, 1, DMA_TO_DEVICE);
+	desc = dmaengine_prep_slave_sg(channel,
+				sgl, 1, DMA_MEM_TO_DEV,
+				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	/* [3] submit the DMA */
+	ret = start_dma_without_bch_irq(this, desc);
+
+	dma_unmap_sg(this->dev, sgl, 1, DMA_TO_DEVICE);
+
+	return ret;
+}
+
+/* Can we use the upper's buffer directly for DMA? */
+static bool prepare_data_dma(struct gpmi_nand_data *this, const void *buf,
+			     int len, enum dma_data_direction dr)
+{
+	struct scatterlist *sgl = &this->data_sgl;
+	int ret;
+
+	/* 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)
+		memcpy(this->data_buffer_dma, buf, len);
+
+	dma_map_sg(this->dev, sgl, 1, dr);
+
+	return false;
+}
+
+static int gpmi_send_data(struct gpmi_nand_data *this, const void *buf,
+			  int len)
+{
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *channel = get_dma_chan(this);
+	int chip = this->current_chip;
+	int ret;
+	uint32_t command_mode;
+	uint32_t address;
+	u32 pio[2];
+
+	/* [1] PIO */
+	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WRITE;
+	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
+
+	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(chip, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(address)
+		| BF_GPMI_CTRL0_XFER_COUNT(len);
+	pio[1] = 0;
+	desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
+					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+	if (!desc)
+		return -EINVAL;
+
+	/* [2] send DMA request */
+	prepare_data_dma(this, buf, len, DMA_TO_DEVICE);
+	desc = dmaengine_prep_slave_sg(channel, &this->data_sgl,
+					1, DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	/* [3] submit the DMA */
+	ret = start_dma_without_bch_irq(this, desc);
+
+	dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_TO_DEVICE);
+
+	return ret;
+}
+
+static int gpmi_read_data(struct gpmi_nand_data *this, void *buf, int len)
+{
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *channel = get_dma_chan(this);
+	int chip = this->current_chip;
+	int ret;
+	u32 pio[2];
+	bool direct;
+
+	/* [1] : send PIO */
+	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(BV_GPMI_CTRL0_COMMAND_MODE__READ)
+		| 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_DATA)
+		| BF_GPMI_CTRL0_XFER_COUNT(len);
+	pio[1] = 0;
+	desc = dmaengine_prep_slave_sg(channel,
+					(struct scatterlist *)pio,
+					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+	if (!desc)
+		return -EINVAL;
+
+	/* [2] : send DMA request */
+	direct = prepare_data_dma(this, buf, len, DMA_FROM_DEVICE);
+	desc = dmaengine_prep_slave_sg(channel, &this->data_sgl,
+					1, DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	/* [3] : submit the DMA */
+
+	ret = start_dma_without_bch_irq(this, desc);
+
+	dma_unmap_sg(this->dev, &this->data_sgl, 1, DMA_FROM_DEVICE);
+	if (!direct)
+		memcpy(buf, this->data_buffer_dma, len);
+
+	return ret;
+}
+
+static int gpmi_send_page(struct gpmi_nand_data *this,  dma_addr_t payload,
+			  dma_addr_t auxiliary)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	uint32_t command_mode;
+	uint32_t address;
+	uint32_t ecc_command;
+	uint32_t buffer_mask;
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *channel = get_dma_chan(this);
+	int chip = this->current_chip;
+	u32 pio[6];
+
+	/* A DMA descriptor that does an ECC page read. */
+	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WRITE;
+	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
+	ecc_command  = BV_GPMI_ECCCTRL_ECC_CMD__BCH_ENCODE;
+	buffer_mask  = BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE |
+				BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY;
+
+	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(chip, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(address)
+		| BF_GPMI_CTRL0_XFER_COUNT(0);
+	pio[1] = 0;
+	pio[2] = BM_GPMI_ECCCTRL_ENABLE_ECC
+		| BF_GPMI_ECCCTRL_ECC_CMD(ecc_command)
+		| BF_GPMI_ECCCTRL_BUFFER_MASK(buffer_mask);
+	pio[3] = geo->page_size;
+	pio[4] = payload;
+	pio[5] = auxiliary;
+
+	desc = dmaengine_prep_slave_sg(channel,
+					(struct scatterlist *)pio,
+					ARRAY_SIZE(pio), DMA_TRANS_NONE,
+					DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	return start_dma_with_bch_irq(this, desc);
+}
+
+static int gpmi_read_page(struct gpmi_nand_data *this,
+			  dma_addr_t payload, dma_addr_t auxiliary)
+{
+	struct bch_geometry *geo = &this->bch_geometry;
+	uint32_t command_mode;
+	uint32_t address;
+	uint32_t ecc_command;
+	uint32_t buffer_mask;
+	struct dma_async_tx_descriptor *desc;
+	struct dma_chan *channel = get_dma_chan(this);
+	int chip = this->current_chip;
+	u32 pio[6];
+
+	/* [1] Wait for the chip to report ready. */
+	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY;
+	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
+
+	pio[0] =  BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(chip, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(address)
+		| BF_GPMI_CTRL0_XFER_COUNT(0);
+	pio[1] = 0;
+	desc = dmaengine_prep_slave_sg(channel,
+				(struct scatterlist *)pio, 2,
+				DMA_TRANS_NONE, 0);
+	if (!desc)
+		return -EINVAL;
+
+	/* [2] Enable the BCH block and read. */
+	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__READ;
+	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
+	ecc_command  = BV_GPMI_ECCCTRL_ECC_CMD__BCH_DECODE;
+	buffer_mask  = BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_PAGE
+			| BV_GPMI_ECCCTRL_BUFFER_MASK__BCH_AUXONLY;
+
+	pio[0] =  BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(chip, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(address)
+		| BF_GPMI_CTRL0_XFER_COUNT(geo->page_size);
+
+	pio[1] = 0;
+	pio[2] =  BM_GPMI_ECCCTRL_ENABLE_ECC
+		| BF_GPMI_ECCCTRL_ECC_CMD(ecc_command)
+		| BF_GPMI_ECCCTRL_BUFFER_MASK(buffer_mask);
+	pio[3] = geo->page_size;
+	pio[4] = payload;
+	pio[5] = auxiliary;
+	desc = dmaengine_prep_slave_sg(channel,
+					(struct scatterlist *)pio,
+					ARRAY_SIZE(pio), DMA_TRANS_NONE,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	/* [3] Disable the BCH block */
+	command_mode = BV_GPMI_CTRL0_COMMAND_MODE__WAIT_FOR_READY;
+	address      = BV_GPMI_CTRL0_ADDRESS__NAND_DATA;
+
+	pio[0] = BF_GPMI_CTRL0_COMMAND_MODE(command_mode)
+		| BM_GPMI_CTRL0_WORD_LENGTH
+		| BF_GPMI_CTRL0_CS(chip, this)
+		| BF_GPMI_CTRL0_LOCK_CS(LOCK_CS_ENABLE, this)
+		| BF_GPMI_CTRL0_ADDRESS(address)
+		| BF_GPMI_CTRL0_XFER_COUNT(geo->page_size);
+	pio[1] = 0;
+	pio[2] = 0; /* clear GPMI_HW_GPMI_ECCCTRL, disable the BCH. */
+	desc = dmaengine_prep_slave_sg(channel,
+				(struct scatterlist *)pio, 3,
+				DMA_TRANS_NONE,
+				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc)
+		return -EINVAL;
+
+	/* [4] submit the DMA */
+	return start_dma_with_bch_irq(this, desc);
+}
+
+/**
+ * gpmi_copy_bits - copy bits from one memory region to another
+ * @dst: destination buffer
+ * @dst_bit_off: bit offset we're starting to write at
+ * @src: source buffer
+ * @src_bit_off: bit offset we're starting to read from
+ * @nbits: number of bits to copy
+ *
+ * This functions copies bits from one memory region to another, and is used by
+ * the GPMI driver to copy ECC sections which are not guaranteed to be byte
+ * aligned.
+ *
+ * src and dst should not overlap.
+ *
+ */
+static void gpmi_copy_bits(u8 *dst, size_t dst_bit_off, const u8 *src,
+			   size_t src_bit_off, size_t nbits)
+{
+	size_t i;
+	size_t nbytes;
+	u32 src_buffer = 0;
+	size_t bits_in_src_buffer = 0;
+
+	if (!nbits)
+		return;
+
+	/*
+	 * Move src and dst pointers to the closest byte pointer and store bit
+	 * offsets within a byte.
+	 */
+	src += src_bit_off / 8;
+	src_bit_off %= 8;
+
+	dst += dst_bit_off / 8;
+	dst_bit_off %= 8;
+
+	/*
+	 * Initialize the src_buffer value with bits available in the first
+	 * byte of data so that we end up with a byte aligned src pointer.
+	 */
+	if (src_bit_off) {
+		src_buffer = src[0] >> src_bit_off;
+		if (nbits >= (8 - src_bit_off)) {
+			bits_in_src_buffer += 8 - src_bit_off;
+		} else {
+			src_buffer &= GENMASK(nbits - 1, 0);
+			bits_in_src_buffer += nbits;
+		}
+		nbits -= bits_in_src_buffer;
+		src++;
+	}
+
+	/* Calculate the number of bytes that can be copied from src to dst. */
+	nbytes = nbits / 8;
+
+	/* Try to align dst to a byte boundary. */
+	if (dst_bit_off) {
+		if (bits_in_src_buffer < (8 - dst_bit_off) && nbytes) {
+			src_buffer |= src[0] << bits_in_src_buffer;
+			bits_in_src_buffer += 8;
+			src++;
+			nbytes--;
+		}
+
+		if (bits_in_src_buffer >= (8 - dst_bit_off)) {
+			dst[0] &= GENMASK(dst_bit_off - 1, 0);
+			dst[0] |= src_buffer << dst_bit_off;
+			src_buffer >>= (8 - dst_bit_off);
+			bits_in_src_buffer -= (8 - dst_bit_off);
+			dst_bit_off = 0;
+			dst++;
+			if (bits_in_src_buffer > 7) {
+				bits_in_src_buffer -= 8;
+				dst[0] = src_buffer;
+				dst++;
+				src_buffer >>= 8;
+			}
+		}
+	}
+
+	if (!bits_in_src_buffer && !dst_bit_off) {
+		/*
+		 * Both src and dst pointers are byte aligned, thus we can
+		 * just use the optimized memcpy function.
+		 */
+		if (nbytes)
+			memcpy(dst, src, nbytes);
+	} else {
+		/*
+		 * src buffer is not byte aligned, hence we have to copy each
+		 * src byte to the src_buffer variable before extracting a byte
+		 * to store in dst.
+		 */
+		for (i = 0; i < nbytes; i++) {
+			src_buffer |= src[i] << bits_in_src_buffer;
+			dst[i] = src_buffer;
+			src_buffer >>= 8;
+		}
+	}
+	/* Update dst and src pointers */
+	dst += nbytes;
+	src += nbytes;
+
+	/*
+	 * nbits is the number of remaining bits. It should not exceed 8 as
+	 * we've already copied as much bytes as possible.
+	 */
+	nbits %= 8;
+
+	/*
+	 * If there's no more bits to copy to the destination and src buffer
+	 * was already byte aligned, then we're done.
+	 */
+	if (!nbits && !bits_in_src_buffer)
+		return;
+
+	/* Copy the remaining bits to src_buffer */
+	if (nbits)
+		src_buffer |= (*src & GENMASK(nbits - 1, 0)) <<
+			      bits_in_src_buffer;
+	bits_in_src_buffer += nbits;
+
+	/*
+	 * In case there were not enough bits to get a byte aligned dst buffer
+	 * prepare the src_buffer variable to match the dst organization (shift
+	 * src_buffer by dst_bit_off and retrieve the least significant bits
+	 * from dst).
+	 */
+	if (dst_bit_off)
+		src_buffer = (src_buffer << dst_bit_off) |
+			     (*dst & GENMASK(dst_bit_off - 1, 0));
+	bits_in_src_buffer += dst_bit_off;
+
+	/*
+	 * Keep most significant bits from dst if we end up with an unaligned
+	 * number of bits.
+	 */
+	nbytes = bits_in_src_buffer / 8;
+	if (bits_in_src_buffer % 8) {
+		src_buffer |= (dst[nbytes] &
+			       GENMASK(7, bits_in_src_buffer % 8)) <<
+			      (nbytes * 8);
+		nbytes++;
+	}
+
+	/* Copy the remaining bytes to dst */
+	for (i = 0; i < nbytes; i++) {
+		dst[i] = src_buffer;
+		src_buffer >>= 8;
+	}
+}
+
+/* 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)
 {
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
index d0b79bac2728..e6b588c77f2f 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
@@ -159,40 +159,6 @@ struct gpmi_nand_data {
 	void			*private;
 };
 
-/* Common Services */
-int common_nfc_set_geometry(struct gpmi_nand_data *);
-struct dma_chan *get_dma_chan(struct gpmi_nand_data *);
-bool prepare_data_dma(struct gpmi_nand_data *, const void *buf, int len,
-		      enum dma_data_direction dr);
-int start_dma_without_bch_irq(struct gpmi_nand_data *,
-			      struct dma_async_tx_descriptor *);
-int start_dma_with_bch_irq(struct gpmi_nand_data *,
-			   struct dma_async_tx_descriptor *);
-
-/* GPMI-NAND helper function library */
-int gpmi_init(struct gpmi_nand_data *);
-void gpmi_clear_bch(struct gpmi_nand_data *);
-void gpmi_dump_info(struct gpmi_nand_data *);
-int bch_set_geometry(struct gpmi_nand_data *);
-int gpmi_is_ready(struct gpmi_nand_data *, unsigned chip);
-int gpmi_send_command(struct gpmi_nand_data *);
-int gpmi_enable_clk(struct gpmi_nand_data *this);
-int gpmi_disable_clk(struct gpmi_nand_data *this);
-int gpmi_setup_data_interface(struct nand_chip *chip, int chipnr,
-			      const struct nand_data_interface *conf);
-void gpmi_nfc_apply_timings(struct gpmi_nand_data *this);
-int gpmi_read_data(struct gpmi_nand_data *, void *buf, int len);
-int gpmi_send_data(struct gpmi_nand_data *, const void *buf, int len);
-
-int gpmi_send_page(struct gpmi_nand_data *,
-		   dma_addr_t payload, dma_addr_t auxiliary);
-int gpmi_read_page(struct gpmi_nand_data *,
-		   dma_addr_t payload, dma_addr_t auxiliary);
-
-void gpmi_copy_bits(u8 *dst, size_t dst_bit_off,
-		    const u8 *src, size_t src_bit_off,
-		    size_t nbits);
-
 /* BCH : Status Block Completion Codes */
 #define STATUS_GOOD		0x00
 #define STATUS_ERASED		0xff
-- 
2.20.1




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