[PATCH v8 2/2] mtd: rawnand: meson: add support for Amlogic NAND flash controller

[Jianxin Pan]

From: Liang Yang <liang.yang@xxxxxxxxxxx>

Add initial support for the Amlogic NAND flash controller which found
in the Meson-GXBB/GXL/AXG SoCs.

Signed-off-by: Liang Yang <liang.yang@xxxxxxxxxxx>
Signed-off-by: Yixun Lan <yixun.lan@xxxxxxxxxxx>
Signed-off-by: Jianxin Pan <jianxin.pan@xxxxxxxxxxx>
---
 drivers/mtd/nand/raw/Kconfig      |   10 +
 drivers/mtd/nand/raw/Makefile     |    1 +
 drivers/mtd/nand/raw/meson_nand.c | 1467 +++++++++++++++++++++++++++++++++++++
 3 files changed, 1478 insertions(+)
 create mode 100644 drivers/mtd/nand/raw/meson_nand.c

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 1a55d3e..d05ff20 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -541,4 +541,14 @@ config MTD_NAND_TEGRA
 	  is supported. Extra OOB bytes when using HW ECC are currently
 	  not supported.
 
+config MTD_NAND_MESON
+	tristate "Support for NAND controller on Amlogic's Meson SoCs"
+	depends on ARCH_MESON || COMPILE_TEST
+	depends on COMMON_CLK_AMLOGIC
+	select COMMON_CLK_REGMAP_MESON
+	select MFD_SYSCON
+	help
+	  Enables support for NAND controller on Amlogic's Meson SoCs.
+	  This controller is found on Meson GXBB, GXL, AXG SoCs.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index 57159b3..a2cc2fe 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
 obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
 obj-$(CONFIG_MTD_NAND_TEGRA)		+= tegra_nand.o
+obj-$(CONFIG_MTD_NAND_MESON)		+= meson_nand.o
 
 nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
 nand-objs += nand_onfi.o
diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
new file mode 100644
index 0000000..380c4e4
--- /dev/null
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -0,0 +1,1467 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson Nand Flash Controller Driver
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Liang Yang <liang.yang@xxxxxxxxxxx>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#define NFC_REG_CMD		0x00
+#define NFC_CMD_IDLE		(0xc << 14)
+#define NFC_CMD_CLE		(0x5 << 14)
+#define NFC_CMD_ALE		(0x6 << 14)
+#define NFC_CMD_ADL		((0 << 16) | (3 << 20))
+#define NFC_CMD_ADH		((1 << 16) | (3 << 20))
+#define NFC_CMD_AIL		((2 << 16) | (3 << 20))
+#define NFC_CMD_AIH		((3 << 16) | (3 << 20))
+#define NFC_CMD_SEED		((8 << 16) | (3 << 20))
+#define NFC_CMD_M2N		((0 << 17) | (2 << 20))
+#define NFC_CMD_N2M		((1 << 17) | (2 << 20))
+#define NFC_CMD_RB		BIT(20)
+#define NFC_CMD_SCRAMBLER_ENABLE	BIT(19)
+#define NFC_CMD_SCRAMBLER_DISABLE	0
+#define NFC_CMD_SHORTMODE_DISABLE	0
+#define NFC_CMD_RB_INT		BIT(14)
+
+#define NFC_CMD_GET_SIZE(x)	(((x) >> 22) & GENMASK(4, 0))
+
+#define NFC_REG_CFG		0x04
+#define NFC_REG_DADR		0x08
+#define NFC_REG_IADR		0x0c
+#define NFC_REG_BUF		0x10
+#define NFC_REG_INFO		0x14
+#define NFC_REG_DC		0x18
+#define NFC_REG_ADR		0x1c
+#define NFC_REG_DL		0x20
+#define NFC_REG_DH		0x24
+#define NFC_REG_CADR		0x28
+#define NFC_REG_SADR		0x2c
+#define NFC_REG_PINS		0x30
+#define NFC_REG_VER		0x38
+
+#define NFC_RB_IRQ_EN		BIT(21)
+
+#define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages)	\
+	(								\
+		(cmd_dir)			|			\
+		((ran) << 19)			|			\
+		((bch) << 14)			|			\
+		((short_mode) << 13)		|			\
+		(((page_size) & 0x7f) << 6)	|			\
+		((pages) & 0x3f)					\
+	)
+
+#define GENCMDDADDRL(adl, addr)		((adl) | ((addr) & 0xffff))
+#define GENCMDDADDRH(adh, addr)		((adh) | (((addr) >> 16) & 0xffff))
+#define GENCMDIADDRL(ail, addr)		((ail) | ((addr) & 0xffff))
+#define GENCMDIADDRH(aih, addr)		((aih) | (((addr) >> 16) & 0xffff))
+
+#define DMA_DIR(dir)		((dir) ? NFC_CMD_N2M : NFC_CMD_M2N)
+
+#define ECC_CHECK_RETURN_FF	(-1)
+
+#define NAND_CE0		(0xe << 10)
+#define NAND_CE1		(0xd << 10)
+
+#define DMA_BUSY_TIMEOUT	0x100000
+#define CMD_FIFO_EMPTY_TIMEOUT	1000
+
+#define MAX_CE_NUM		2
+
+/* eMMC clock register, misc control */
+#define CLK_SELECT_NAND		BIT(31)
+
+#define NFC_CLK_CYCLE		6
+
+/* nand flash controller delay 3 ns */
+#define NFC_DEFAULT_DELAY	3000
+
+#define ROW_ADDER(page, index)	(((page) >> (8 * (index))) & 0xff)
+#define MAX_CYCLE_ADDRS		5
+#define DIRREAD			1
+#define DIRWRITE		0
+
+#define ECC_PARITY_BCH8_512B	14
+#define ECC_COMPLETE            BIT(31)
+#define ECC_ERR_CNT(x)		(((x) >> 24) & GENMASK(5, 0))
+#define ECC_ZERO_CNT(x)		(((x) >> 16) & GENMASK(5, 0))
+#define ECC_UNCORRECTABLE	0x3f
+
+#define PER_INFO_BYTE		8
+
+struct meson_nfc_nand_chip {
+	struct list_head node;
+	struct nand_chip nand;
+	unsigned long clk_rate;
+	unsigned long level1_divider;
+	u32 bus_timing;
+	u32 twb;
+	u32 tadl;
+	u32 tbers_max;
+
+	u32 bch_mode;
+	u8 *data_buf;
+	__le64 *info_buf;
+	u32 nsels;
+	u8 sels[0];
+};
+
+struct meson_nand_ecc {
+	u32 bch;
+	u32 strength;
+};
+
+struct meson_nfc_data {
+	const struct nand_ecc_caps *ecc_caps;
+};
+
+struct meson_nfc_param {
+	u32 chip_select;
+	u32 rb_select;
+};
+
+struct nand_rw_cmd {
+	u32 cmd0;
+	u32 addrs[MAX_CYCLE_ADDRS];
+	u32 cmd1;
+};
+
+struct nand_timing {
+	u32 twb;
+	u32 tadl;
+	u32 tbers_max;
+};
+
+struct meson_nfc {
+	struct nand_controller controller;
+	struct clk *core_clk;
+	struct clk *device_clk;
+	struct clk *phase_tx;
+	struct clk *phase_rx;
+
+	unsigned long clk_rate;
+	u32 bus_timing;
+
+	struct device *dev;
+	void __iomem *reg_base;
+	struct regmap *reg_clk;
+	struct completion completion;
+	struct list_head chips;
+	const struct meson_nfc_data *data;
+	struct meson_nfc_param param;
+	struct nand_timing timing;
+	union {
+		int cmd[32];
+		struct nand_rw_cmd rw;
+	} cmdfifo;
+
+	dma_addr_t daddr;
+	dma_addr_t iaddr;
+
+	unsigned long assigned_cs;
+};
+
+enum {
+	NFC_ECC_BCH8_1K		= 2,
+	NFC_ECC_BCH24_1K,
+	NFC_ECC_BCH30_1K,
+	NFC_ECC_BCH40_1K,
+	NFC_ECC_BCH50_1K,
+	NFC_ECC_BCH60_1K,
+};
+
+#define MESON_ECC_DATA(b, s)	{ .bch = (b),	.strength = (s)}
+
+static struct meson_nand_ecc meson_ecc[] = {
+	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8),
+	MESON_ECC_DATA(NFC_ECC_BCH24_1K, 24),
+	MESON_ECC_DATA(NFC_ECC_BCH30_1K, 30),
+	MESON_ECC_DATA(NFC_ECC_BCH40_1K, 40),
+	MESON_ECC_DATA(NFC_ECC_BCH50_1K, 50),
+	MESON_ECC_DATA(NFC_ECC_BCH60_1K, 60),
+};
+
+static int meson_nand_calc_ecc_bytes(int step_size, int strength)
+{
+	int ecc_bytes;
+
+	if (step_size == 512 && strength == 8)
+		return ECC_PARITY_BCH8_512B;
+
+	ecc_bytes = DIV_ROUND_UP(strength * fls(step_size * 8), 8);
+	ecc_bytes = ALIGN(ecc_bytes, 2);
+
+	return ecc_bytes;
+}
+
+NAND_ECC_CAPS_SINGLE(meson_gxl_ecc_caps,
+		     meson_nand_calc_ecc_bytes, 1024, 8, 24, 30, 40, 50, 60);
+NAND_ECC_CAPS_SINGLE(meson_axg_ecc_caps,
+		     meson_nand_calc_ecc_bytes, 1024, 8);
+
+static struct meson_nfc_nand_chip *to_meson_nand(struct nand_chip *nand)
+{
+	return container_of(nand, struct meson_nfc_nand_chip, nand);
+}
+
+static void meson_nfc_select_chip(struct nand_chip *nand, int chip)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	int ret, value;
+
+	if (chip < 0 || WARN_ON_ONCE(chip > MAX_CE_NUM))
+		return;
+
+	nfc->param.chip_select = meson_chip->sels[chip] ? NAND_CE1 : NAND_CE0;
+	nfc->param.rb_select = nfc->param.chip_select;
+	nfc->timing.twb = meson_chip->twb;
+	nfc->timing.tadl = meson_chip->tadl;
+	nfc->timing.tbers_max = meson_chip->tbers_max;
+
+	if (chip >= 0) {
+		if (nfc->clk_rate != meson_chip->clk_rate) {
+			ret = clk_set_rate(nfc->device_clk,
+					   meson_chip->clk_rate);
+			if (ret) {
+				dev_err(nfc->dev, "failed to set clock rate\n");
+				return;
+			}
+			nfc->clk_rate = meson_chip->clk_rate;
+		}
+		if (nfc->bus_timing != meson_chip->bus_timing) {
+			value = (NFC_CLK_CYCLE - 1)
+				| (meson_chip->bus_timing << 5);
+			writel(value, nfc->reg_base + NFC_REG_CFG);
+			writel((1 << 31), nfc->reg_base + NFC_REG_CMD);
+			nfc->bus_timing =  meson_chip->bus_timing;
+		}
+	}
+}
+
+static void meson_nfc_cmd_idle(struct meson_nfc *nfc, u32 time)
+{
+	writel(nfc->param.chip_select | NFC_CMD_IDLE | (time & 0x3ff),
+	       nfc->reg_base + NFC_REG_CMD);
+}
+
+static void meson_nfc_cmd_seed(struct meson_nfc *nfc, u32 seed)
+{
+	writel(NFC_CMD_SEED | (0xc2 + (seed & 0x7fff)),
+	       nfc->reg_base + NFC_REG_CMD);
+}
+
+static void meson_nfc_cmd_access(struct nand_chip *nand, int raw, bool dir,
+				 int scrambler)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	u32 bch = meson_chip->bch_mode, cmd;
+	int len = mtd->writesize, pagesize, pages;
+
+	pagesize = nand->ecc.size;
+
+	if (raw) {
+		len = mtd->writesize + mtd->oobsize;
+		cmd = (len & GENMASK(5, 0)) | scrambler | DMA_DIR(dir);
+		writel(cmd, nfc->reg_base + NFC_REG_CMD);
+		return;
+	}
+
+	pages = len / nand->ecc.size;
+
+	cmd = CMDRWGEN(DMA_DIR(dir), scrambler, bch,
+		       NFC_CMD_SHORTMODE_DISABLE, pagesize, pages);
+
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+}
+
+static void meson_nfc_drain_cmd(struct meson_nfc *nfc)
+{
+	/*
+	 * Insert two commands to make sure all valid commands are finished.
+	 *
+	 * The Nand flash controller is designed as two stages pipleline -
+	 *  a) fetch and b) excute.
+	 * There might be cases when the driver see command queue is empty,
+	 * but the Nand flash controller still has two commands buffered,
+	 * one is fetched into NFC request queue (ready to run), and another
+	 * is actively executing. So pushing 2 "IDLE" commands guarantees that
+	 * the pipeline is emptied.
+	 */
+	meson_nfc_cmd_idle(nfc, 0);
+	meson_nfc_cmd_idle(nfc, 0);
+}
+
+static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
+				     unsigned int timeout_ms)
+{
+	u32 cmd_size = 0;
+	int ret;
+
+	/* wait cmd fifo is empty */
+	ret = readl_relaxed_poll_timeout(nfc->reg_base + NFC_REG_CMD, cmd_size,
+					 !NFC_CMD_GET_SIZE(cmd_size),
+					 10, timeout_ms * 1000);
+	if (ret)
+		dev_err(nfc->dev, "wait for empty CMD FIFO time out\n");
+
+	return ret;
+}
+
+static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
+{
+	meson_nfc_drain_cmd(nfc);
+
+	return meson_nfc_wait_cmd_finish(nfc, DMA_BUSY_TIMEOUT);
+}
+
+static u8 *meson_nfc_oob_ptr(struct nand_chip *nand, int i)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	int len;
+
+	len = nand->ecc.size * (i + 1) + (nand->ecc.bytes + 2) * i;
+
+	return meson_chip->data_buf + len;
+}
+
+static u8 *meson_nfc_data_ptr(struct nand_chip *nand, int i)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	int len, temp;
+
+	temp = nand->ecc.size + nand->ecc.bytes;
+	len = (temp + 2) * i;
+
+	return meson_chip->data_buf + len;
+}
+
+static void meson_nfc_get_data_oob(struct nand_chip *nand,
+				   u8 *buf, u8 *oobbuf)
+{
+	int i, oob_len = 0;
+	u8 *dsrc, *osrc;
+
+	oob_len = nand->ecc.bytes + 2;
+	for (i = 0; i < nand->ecc.steps; i++) {
+		if (buf) {
+			dsrc = meson_nfc_data_ptr(nand, i);
+			memcpy(buf, dsrc, nand->ecc.size);
+			buf += nand->ecc.size;
+		}
+		osrc = meson_nfc_oob_ptr(nand, i);
+		memcpy(oobbuf, osrc, oob_len);
+		oobbuf += oob_len;
+	}
+}
+
+static void meson_nfc_set_data_oob(struct nand_chip *nand,
+				   const u8 *buf, u8 *oobbuf)
+{
+	int i, oob_len = 0;
+	u8 *dsrc, *osrc;
+
+	oob_len = nand->ecc.bytes + 2;
+	for (i = 0; i < nand->ecc.steps; i++) {
+		if (buf) {
+			dsrc = meson_nfc_data_ptr(nand, i);
+			memcpy(dsrc, buf, nand->ecc.size);
+			buf += nand->ecc.size;
+		}
+		osrc = meson_nfc_oob_ptr(nand, i);
+		memcpy(osrc, oobbuf, oob_len);
+		oobbuf += oob_len;
+	}
+}
+
+static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
+{
+	u32 cmd, cfg;
+	int ret = 0;
+
+	meson_nfc_cmd_idle(nfc, nfc->timing.twb);
+	meson_nfc_drain_cmd(nfc);
+	meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
+
+	cfg = readl(nfc->reg_base + NFC_REG_CFG);
+	cfg |= NFC_RB_IRQ_EN;
+	writel(cfg, nfc->reg_base + NFC_REG_CFG);
+
+	init_completion(&nfc->completion);
+
+	/* use the max erase time as the maximum clock for waiting R/B */
+	cmd = NFC_CMD_RB | NFC_CMD_RB_INT
+		| nfc->param.chip_select | nfc->timing.tbers_max;
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	ret = wait_for_completion_timeout(&nfc->completion,
+					  msecs_to_jiffies(timeout_ms));
+	if (ret == 0)
+		ret = -1;
+
+	return ret;
+}
+
+static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	__le64 *info;
+	int i, count;
+
+	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
+		info = &meson_chip->info_buf[i];
+		*info |= oob_buf[count];
+		*info |= oob_buf[count + 1] << 8;
+	}
+}
+
+static void meson_nfc_get_user_byte(struct nand_chip *nand, u8 *oob_buf)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	__le64 *info;
+	int i, count;
+
+	for (i = 0, count = 0; i < nand->ecc.steps; i++, count += 2) {
+		info = &meson_chip->info_buf[i];
+		oob_buf[count] = *info;
+		oob_buf[count + 1] = *info >> 8;
+	}
+}
+
+static int meson_nfc_ecc_correct(struct nand_chip *nand, u32 *bitflips,
+				 u64 *correct_bitmap)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	__le64 *info;
+	int ret = 0, i;
+
+	for (i = 0; i < nand->ecc.steps; i++) {
+		info = &meson_chip->info_buf[i];
+		if (ECC_ERR_CNT(*info) != ECC_UNCORRECTABLE) {
+			mtd->ecc_stats.corrected += ECC_ERR_CNT(*info);
+			*bitflips = max_t(u32, *bitflips, ECC_ERR_CNT(*info));
+			*correct_bitmap |= 1 >> i;
+			continue;
+		}
+		if ((nand->options & NAND_NEED_SCRAMBLING) &&
+		    ECC_ZERO_CNT(*info) < nand->ecc.strength) {
+			mtd->ecc_stats.corrected += ECC_ZERO_CNT(*info);
+			*bitflips = max_t(u32, *bitflips,
+					  ECC_ZERO_CNT(*info));
+			ret = ECC_CHECK_RETURN_FF;
+		} else {
+			ret = -EBADMSG;
+		}
+	}
+	return ret;
+}
+
+static int meson_nfc_dma_buffer_setup(struct nand_chip *nand, u8 *databuf,
+				      int datalen, u8 *infobuf, int infolen,
+				      enum dma_data_direction dir)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	u32 cmd;
+	int ret = 0;
+
+	nfc->daddr = dma_map_single(nfc->dev, (void *)databuf, datalen, dir);
+	ret = dma_mapping_error(nfc->dev, nfc->daddr);
+	if (ret) {
+		dev_err(nfc->dev, "DMA mapping error\n");
+		return ret;
+	}
+	cmd = GENCMDDADDRL(NFC_CMD_ADL, nfc->daddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	cmd = GENCMDDADDRH(NFC_CMD_ADH, nfc->daddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	if (infobuf) {
+		nfc->iaddr = dma_map_single(nfc->dev, infobuf, infolen, dir);
+		ret = dma_mapping_error(nfc->dev, nfc->iaddr);
+		if (ret) {
+			dev_err(nfc->dev, "DMA mapping error\n");
+			dma_unmap_single(nfc->dev,
+					 nfc->daddr, datalen, dir);
+			return ret;
+		}
+		cmd = GENCMDIADDRL(NFC_CMD_AIL, nfc->iaddr);
+		writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+		cmd = GENCMDIADDRH(NFC_CMD_AIH, nfc->iaddr);
+		writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	}
+
+	return ret;
+}
+
+static void meson_nfc_dma_buffer_release(struct nand_chip *nand,
+					 int infolen, int datalen,
+					 enum dma_data_direction dir)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+
+	dma_unmap_single(nfc->dev, nfc->daddr, datalen, dir);
+	if (infolen)
+		dma_unmap_single(nfc->dev, nfc->iaddr, infolen, dir);
+}
+
+static int meson_nfc_read_buf(struct nand_chip *nand, u8 *buf, int len)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	int ret = 0;
+	u32 cmd;
+	u8 *info;
+
+	info = kzalloc(PER_INFO_BYTE, GFP_KERNEL);
+	ret = meson_nfc_dma_buffer_setup(nand, buf, len, info,
+					 PER_INFO_BYTE, DMA_FROM_DEVICE);
+	if (ret)
+		return ret;
+
+	cmd = NFC_CMD_N2M | (len & GENMASK(5, 0));
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	meson_nfc_drain_cmd(nfc);
+	meson_nfc_wait_cmd_finish(nfc, 1000);
+	meson_nfc_dma_buffer_release(nand, len, PER_INFO_BYTE, DMA_FROM_DEVICE);
+	kfree(info);
+
+	return ret;
+}
+
+static int meson_nfc_write_buf(struct nand_chip *nand, u8 *buf, int len)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	int ret = 0;
+	u32 cmd;
+
+	ret = meson_nfc_dma_buffer_setup(nand, buf, len, NULL,
+					 0, DMA_TO_DEVICE);
+	if (ret)
+		return ret;
+
+	cmd = NFC_CMD_M2N | (len & GENMASK(5, 0));
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	meson_nfc_drain_cmd(nfc);
+	meson_nfc_wait_cmd_finish(nfc, 1000);
+	meson_nfc_dma_buffer_release(nand, len, 0, DMA_TO_DEVICE);
+
+	return ret;
+}
+
+static int meson_nfc_rw_cmd_prepare_and_execute(struct nand_chip *nand,
+						int page, bool in)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	const struct nand_sdr_timings *sdr =
+		nand_get_sdr_timings(&nand->data_interface);
+	u32 *addrs = nfc->cmdfifo.rw.addrs;
+	u32 cs = nfc->param.chip_select;
+	u32 cmd0, cmd_num, row_start;
+	int ret = 0, i;
+
+	cmd_num = sizeof(struct nand_rw_cmd) / sizeof(int);
+
+	cmd0 = in ? NAND_CMD_READ0 : NAND_CMD_SEQIN;
+	nfc->cmdfifo.rw.cmd0 = cs | NFC_CMD_CLE | cmd0;
+
+	addrs[0] = cs | NFC_CMD_ALE | 0;
+	if (mtd->writesize <= 512) {
+		cmd_num--;
+		row_start = 1;
+	} else {
+		addrs[1] = cs | NFC_CMD_ALE | 0;
+		row_start = 2;
+	}
+
+	addrs[row_start] = cs | NFC_CMD_ALE | ROW_ADDER(page, 0);
+	addrs[row_start + 1] = cs | NFC_CMD_ALE | ROW_ADDER(page, 1);
+
+	if (nand->options & NAND_ROW_ADDR_3)
+		addrs[row_start + 2] =
+			cs | NFC_CMD_ALE | ROW_ADDER(page, 2);
+	else
+		cmd_num--;
+
+	/* subtract cmd1 */
+	cmd_num--;
+
+	for (i = 0; i < cmd_num; i++)
+		writel_relaxed(nfc->cmdfifo.cmd[i],
+			       nfc->reg_base + NFC_REG_CMD);
+
+	if (in) {
+		nfc->cmdfifo.rw.cmd1 = cs | NFC_CMD_CLE | NAND_CMD_READSTART;
+		writel(nfc->cmdfifo.rw.cmd1, nfc->reg_base + NFC_REG_CMD);
+		meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tR_max));
+	} else {
+		meson_nfc_cmd_idle(nfc, nfc->timing.tadl);
+	}
+
+	return ret;
+}
+
+static int meson_nfc_write_page_sub(struct nand_chip *nand,
+				    int page, int raw)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	const struct nand_sdr_timings *sdr =
+		nand_get_sdr_timings(&nand->data_interface);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	int data_len, info_len;
+	u32 cmd;
+	int ret;
+
+	meson_nfc_select_chip(nand, nand->cur_cs);
+
+	data_len =  mtd->writesize + mtd->oobsize;
+	info_len = nand->ecc.steps * PER_INFO_BYTE;
+
+	ret = meson_nfc_rw_cmd_prepare_and_execute(nand, page, DIRWRITE);
+	if (ret)
+		return ret;
+
+	ret = meson_nfc_dma_buffer_setup(nand, meson_chip->data_buf,
+					 data_len, (u8 *)meson_chip->info_buf,
+					 info_len, DMA_TO_DEVICE);
+	if (ret)
+		return ret;
+
+	if (nand->options & NAND_NEED_SCRAMBLING) {
+		meson_nfc_cmd_seed(nfc, page);
+		meson_nfc_cmd_access(nand, raw, DIRWRITE,
+				     NFC_CMD_SCRAMBLER_ENABLE);
+	} else {
+		meson_nfc_cmd_access(nand, raw, DIRWRITE,
+				     NFC_CMD_SCRAMBLER_DISABLE);
+	}
+
+	cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_PAGEPROG;
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max));
+
+	meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_TO_DEVICE);
+
+	return ret;
+}
+
+static int meson_nfc_write_page_raw(struct nand_chip *nand, const u8 *buf,
+				    int oob_required, int page)
+{
+	u8 *oob_buf = nand->oob_poi;
+
+	meson_nfc_set_data_oob(nand, buf, oob_buf);
+
+	return meson_nfc_write_page_sub(nand, page, 1);
+}
+
+static int meson_nfc_write_page_hwecc(struct nand_chip *nand,
+				      const u8 *buf, int oob_required, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	u8 *oob_buf = nand->oob_poi;
+
+	memcpy(meson_chip->data_buf, buf, mtd->writesize);
+	memset(meson_chip->info_buf, 0, nand->ecc.steps * PER_INFO_BYTE);
+	meson_nfc_set_user_byte(nand, oob_buf);
+
+	return meson_nfc_write_page_sub(nand, page, 0);
+}
+
+static void meson_nfc_check_ecc_pages_valid(struct meson_nfc *nfc,
+					    struct nand_chip *nand, int raw)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	__le64 *info;
+	u32 neccpages;
+	int ret;
+
+	neccpages = raw ? 1 : nand->ecc.steps;
+	info = &meson_chip->info_buf[neccpages - 1];
+	do {
+		usleep_range(10, 15);
+		/* info is updated by nfc dma engine*/
+		smp_rmb();
+		ret = *info & ECC_COMPLETE;
+	} while (!ret);
+}
+
+static int meson_nfc_read_page_sub(struct nand_chip *nand,
+				   int page, int raw)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	int data_len, info_len;
+	int ret;
+
+	meson_nfc_select_chip(nand, nand->cur_cs);
+
+	data_len =  mtd->writesize + mtd->oobsize;
+	info_len = nand->ecc.steps * PER_INFO_BYTE;
+
+	ret = meson_nfc_rw_cmd_prepare_and_execute(nand, page, DIRREAD);
+	if (ret)
+		return ret;
+
+	ret = meson_nfc_dma_buffer_setup(nand, meson_chip->data_buf,
+					 data_len, (u8 *)meson_chip->info_buf,
+					 info_len, DMA_FROM_DEVICE);
+	if (ret)
+		return ret;
+
+	if (nand->options & NAND_NEED_SCRAMBLING) {
+		meson_nfc_cmd_seed(nfc, page);
+		meson_nfc_cmd_access(nand, raw, DIRREAD,
+				     NFC_CMD_SCRAMBLER_ENABLE);
+	} else {
+		meson_nfc_cmd_access(nand, raw, DIRREAD,
+				     NFC_CMD_SCRAMBLER_DISABLE);
+	}
+
+	ret = meson_nfc_wait_dma_finish(nfc);
+	meson_nfc_check_ecc_pages_valid(nfc, nand, raw);
+
+	meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_FROM_DEVICE);
+
+	return ret;
+}
+
+static int meson_nfc_read_page_raw(struct nand_chip *nand, u8 *buf,
+				   int oob_required, int page)
+{
+	u8 *oob_buf = nand->oob_poi;
+	int ret;
+
+	ret = meson_nfc_read_page_sub(nand, page, 1);
+	if (ret)
+		return ret;
+
+	meson_nfc_get_data_oob(nand, buf, oob_buf);
+
+	return 0;
+}
+
+static int meson_nfc_read_page_hwecc(struct nand_chip *nand, u8 *buf,
+				     int oob_required, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct nand_ecc_ctrl *ecc = &nand->ecc;
+	u64 correct_bitmap = 0;
+	u32 bitflips = 0;
+	u8 *oob_buf = nand->oob_poi;
+	int ret, i;
+
+	ret = meson_nfc_read_page_sub(nand, page, 0);
+	if (ret)
+		return ret;
+
+	meson_nfc_get_user_byte(nand, oob_buf);
+	ret = meson_nfc_ecc_correct(nand, &bitflips, &correct_bitmap);
+	if (ret == ECC_CHECK_RETURN_FF) {
+		if (buf)
+			memset(buf, 0xff, mtd->writesize);
+		memset(oob_buf, 0xff, mtd->oobsize);
+	} else if (ret < 0) {
+		if ((nand->options & NAND_NEED_SCRAMBLING) || !buf) {
+			mtd->ecc_stats.failed++;
+			return bitflips;
+		}
+		ret  = meson_nfc_read_page_raw(nand, buf, 0, page);
+		if (ret)
+			return ret;
+
+		for (i = 0; i < nand->ecc.steps ; i++) {
+			u8 *data = buf + i * ecc->size;
+			u8 *oob = nand->oob_poi + i * (ecc->bytes + 2);
+
+			if (correct_bitmap & (1 << i))
+				continue;
+			ret = nand_check_erased_ecc_chunk(data,	ecc->size,
+							  oob, ecc->bytes + 2,
+							  NULL, 0,
+							  ecc->strength);
+			if (ret < 0) {
+				mtd->ecc_stats.failed++;
+			} else {
+				mtd->ecc_stats.corrected += ret;
+				bitflips =  max_t(u32, bitflips, ret);
+			}
+		}
+	} else if (buf && buf != meson_chip->data_buf) {
+		memcpy(buf, meson_chip->data_buf, mtd->writesize);
+	}
+
+	return bitflips;
+}
+
+static int meson_nfc_read_oob_raw(struct nand_chip *nand, int page)
+{
+	return meson_nfc_read_page_raw(nand, NULL, 1, page);
+}
+
+static int meson_nfc_read_oob(struct nand_chip *nand, int page)
+{
+	return meson_nfc_read_page_hwecc(nand, NULL, 1, page);
+}
+
+bool meson_nfc_is_buffer_dma_safe(const void *buffer)
+{
+	if (virt_addr_valid(buffer) && (!object_is_on_stack(buffer)))
+		return true;
+	return false;
+}
+
+void *
+meson_nand_op_get_dma_safe_input_buf(const struct nand_op_instr *instr)
+{
+	if (WARN_ON(instr->type != NAND_OP_DATA_IN_INSTR))
+		return NULL;
+
+	if (meson_nfc_is_buffer_dma_safe(instr->ctx.data.buf.in))
+		return instr->ctx.data.buf.in;
+
+	return kzalloc(instr->ctx.data.len, GFP_KERNEL);
+}
+
+void
+meson_nand_op_put_dma_safe_input_buf(const struct nand_op_instr *instr,
+				     void *buf)
+{
+	if (WARN_ON(instr->type != NAND_OP_DATA_IN_INSTR) ||
+	    WARN_ON(!buf))
+		return;
+
+	if (buf == instr->ctx.data.buf.in)
+		return;
+
+	memcpy(instr->ctx.data.buf.in, buf, instr->ctx.data.len);
+	kfree(buf);
+}
+
+void *
+meson_nand_op_get_dma_safe_output_buf(const struct nand_op_instr *instr)
+{
+	if (WARN_ON(instr->type != NAND_OP_DATA_OUT_INSTR))
+		return NULL;
+
+	if (meson_nfc_is_buffer_dma_safe(instr->ctx.data.buf.out))
+		return (void *)instr->ctx.data.buf.out;
+
+	return kmemdup(instr->ctx.data.buf.out,
+		       instr->ctx.data.len, GFP_KERNEL);
+}
+
+void
+meson_nand_op_put_dma_safe_output_buf(const struct nand_op_instr *instr,
+				      const void *buf)
+{
+	if (WARN_ON(instr->type != NAND_OP_DATA_OUT_INSTR) ||
+	    WARN_ON(!buf))
+		return;
+
+	if (buf != instr->ctx.data.buf.out)
+		kfree(buf);
+}
+
+static int meson_nfc_exec_op(struct nand_chip *nand,
+			     const struct nand_operation *op, bool check_only)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	const struct nand_op_instr *instr = NULL;
+	void *buf;
+	u32 op_id, delay_idle, cmd;
+	int i;
+
+	meson_nfc_select_chip(nand, op->cs);
+	for (op_id = 0; op_id < op->ninstrs; op_id++) {
+		instr = &op->instrs[op_id];
+		delay_idle = DIV_ROUND_UP(PSEC_TO_NSEC(instr->delay_ns),
+					  meson_chip->level1_divider *
+					  NFC_CLK_CYCLE);
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			cmd = nfc->param.chip_select | NFC_CMD_CLE;
+			cmd |= instr->ctx.cmd.opcode & 0xff;
+			writel(cmd, nfc->reg_base + NFC_REG_CMD);
+			meson_nfc_cmd_idle(nfc, delay_idle);
+			break;
+
+		case NAND_OP_ADDR_INSTR:
+			for (i = 0; i < instr->ctx.addr.naddrs; i++) {
+				cmd = nfc->param.chip_select | NFC_CMD_ALE;
+				cmd |= instr->ctx.addr.addrs[i] & 0xff;
+				writel(cmd, nfc->reg_base + NFC_REG_CMD);
+			}
+			meson_nfc_cmd_idle(nfc, delay_idle);
+			break;
+
+		case NAND_OP_DATA_IN_INSTR:
+			buf = meson_nand_op_get_dma_safe_input_buf(instr);
+			if (!buf)
+				return -ENOMEM;
+			meson_nfc_read_buf(nand, buf, instr->ctx.data.len);
+			meson_nand_op_put_dma_safe_input_buf(instr, buf);
+			break;
+
+		case NAND_OP_DATA_OUT_INSTR:
+			buf = meson_nand_op_get_dma_safe_output_buf(instr);
+			if (!buf)
+				return -ENOMEM;
+			meson_nfc_write_buf(nand, buf, instr->ctx.data.len);
+			meson_nand_op_put_dma_safe_output_buf(instr, buf);
+			break;
+
+		case NAND_OP_WAITRDY_INSTR:
+			meson_nfc_queue_rb(nfc, instr->ctx.waitrdy.timeout_ms);
+			if (instr->delay_ns)
+				meson_nfc_cmd_idle(nfc, delay_idle);
+			break;
+		}
+	}
+	meson_nfc_wait_cmd_finish(nfc, 1000);
+	return 0;
+}
+
+static int meson_ooblayout_ecc(struct mtd_info *mtd, int section,
+			       struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (section >= nand->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset =  2 + (section * (2 + nand->ecc.bytes));
+	oobregion->length = nand->ecc.bytes;
+
+	return 0;
+}
+
+static int meson_ooblayout_free(struct mtd_info *mtd, int section,
+				struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (section >= nand->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset = section * (2 + nand->ecc.bytes);
+	oobregion->length = 2;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
+	.ecc = meson_ooblayout_ecc,
+	.free = meson_ooblayout_free,
+};
+
+static int meson_nfc_clk_init(struct meson_nfc *nfc)
+{
+	int ret;
+
+	/* request core clock */
+	nfc->core_clk = devm_clk_get(nfc->dev, "core");
+	if (IS_ERR(nfc->core_clk)) {
+		dev_err(nfc->dev, "failed to get core clock\n");
+		return PTR_ERR(nfc->core_clk);
+	}
+
+	nfc->device_clk = devm_clk_get(nfc->dev, "device");
+	if (IS_ERR(nfc->device_clk)) {
+		dev_err(nfc->dev, "failed to get device clock\n");
+		return PTR_ERR(nfc->device_clk);
+	}
+
+	nfc->phase_tx = devm_clk_get(nfc->dev, "tx");
+	if (IS_ERR(nfc->phase_tx)) {
+		dev_err(nfc->dev, "failed to get TX clk\n");
+		return PTR_ERR(nfc->phase_tx);
+	}
+
+	nfc->phase_rx = devm_clk_get(nfc->dev, "rx");
+	if (IS_ERR(nfc->phase_rx)) {
+		dev_err(nfc->dev, "failed to get RX clk\n");
+		return PTR_ERR(nfc->phase_rx);
+	}
+
+	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
+	regmap_update_bits(nfc->reg_clk,
+			   0, CLK_SELECT_NAND, CLK_SELECT_NAND);
+
+	ret = clk_prepare_enable(nfc->core_clk);
+	if (ret) {
+		dev_err(nfc->dev, "failed to enable core clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(nfc->device_clk);
+	if (ret) {
+		dev_err(nfc->dev, "failed to enable device clock\n");
+		goto err_device_clk;
+	}
+
+	ret = clk_prepare_enable(nfc->phase_tx);
+	if (ret) {
+		dev_err(nfc->dev, "failed to enable TX clock\n");
+		goto err_phase_tx;
+	}
+
+	ret = clk_prepare_enable(nfc->phase_rx);
+	if (ret) {
+		dev_err(nfc->dev, "failed to enable RX clock\n");
+		goto err_phase_rx;
+	}
+
+	ret = clk_set_rate(nfc->device_clk, 24000000);
+	if (ret)
+		goto err_phase_rx;
+
+	return 0;
+err_phase_rx:
+	clk_disable_unprepare(nfc->phase_tx);
+err_phase_tx:
+	clk_disable_unprepare(nfc->device_clk);
+err_device_clk:
+	clk_disable_unprepare(nfc->core_clk);
+	return ret;
+}
+
+static void meson_nfc_disable_clk(struct meson_nfc *nfc)
+{
+	clk_disable_unprepare(nfc->phase_rx);
+	clk_disable_unprepare(nfc->phase_tx);
+	clk_disable_unprepare(nfc->device_clk);
+	clk_disable_unprepare(nfc->core_clk);
+}
+
+static void meson_nfc_free_buffer(struct nand_chip *nand)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+
+	kfree(meson_chip->info_buf);
+	kfree(meson_chip->data_buf);
+}
+
+static int meson_chip_buffer_init(struct nand_chip *nand)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	u32 page_bytes, info_bytes, nsectors;
+
+	nsectors = mtd->writesize / nand->ecc.size;
+
+	page_bytes =  mtd->writesize + mtd->oobsize;
+	info_bytes = nsectors * PER_INFO_BYTE;
+
+	meson_chip->data_buf = kmalloc(page_bytes, GFP_KERNEL);
+	if (!meson_chip->data_buf)
+		return -ENOMEM;
+
+	meson_chip->info_buf = kmalloc(info_bytes, GFP_KERNEL);
+	if (!meson_chip->info_buf) {
+		kfree(meson_chip->data_buf);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static
+int meson_nfc_setup_data_interface(struct nand_chip *nand, int csline,
+				   const struct nand_data_interface *conf)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	const struct nand_sdr_timings *timings;
+	u32 div, bt_min, bt_max, tbers_clocks;
+
+	timings = nand_get_sdr_timings(conf);
+	if (IS_ERR(timings))
+		return -ENOTSUPP;
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	div = DIV_ROUND_UP((timings->tRC_min / 1000), NFC_CLK_CYCLE);
+	bt_min = (timings->tREA_max + NFC_DEFAULT_DELAY) / div;
+	bt_max = (NFC_DEFAULT_DELAY + timings->tRHOH_min +
+		  timings->tRC_min / 2) / div;
+
+	meson_chip->twb = DIV_ROUND_UP(PSEC_TO_NSEC(timings->tWB_max),
+				       div * NFC_CLK_CYCLE);
+	meson_chip->tadl = DIV_ROUND_UP(PSEC_TO_NSEC(timings->tADL_min),
+					div * NFC_CLK_CYCLE);
+	tbers_clocks = DIV_ROUND_UP(PSEC_TO_NSEC(timings->tBERS_max),
+				    div * NFC_CLK_CYCLE);
+	meson_chip->tbers_max = ilog2(tbers_clocks);
+	if (!is_power_of_2(tbers_clocks))
+		meson_chip->tbers_max++;
+
+	bt_min = DIV_ROUND_UP(bt_min, 1000);
+	bt_max = DIV_ROUND_UP(bt_max, 1000);
+
+	if (bt_max < bt_min)
+		return -EINVAL;
+
+	meson_chip->level1_divider = div;
+	meson_chip->clk_rate = 1000000000 / meson_chip->level1_divider;
+	meson_chip->bus_timing = (bt_min + bt_max) / 2 + 1;
+
+	return 0;
+}
+
+static int meson_nand_bch_mode(struct nand_chip *nand)
+{
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	int i;
+
+	if (nand->ecc.strength > 60 || nand->ecc.strength < 8)
+		return -EINVAL;
+
+	for (i = 0; i < sizeof(meson_ecc); i++) {
+		if (meson_ecc[i].strength == nand->ecc.strength) {
+			meson_chip->bch_mode = meson_ecc[i].bch;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static void meson_nand_detach_chip(struct nand_chip *nand)
+{
+	meson_nfc_free_buffer(nand);
+}
+
+static int meson_nand_attach_chip(struct nand_chip *nand)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	int nsectors = mtd->writesize / 1024;
+	int ret;
+
+	if (!mtd->name) {
+		mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
+					   "%s:nand%d",
+					   dev_name(nfc->dev),
+					   meson_chip->sels[0]);
+		if (!mtd->name)
+			return -ENOMEM;
+	}
+
+	if (nand->bbt_options & NAND_BBT_USE_FLASH)
+		nand->bbt_options |= NAND_BBT_NO_OOB;
+
+	nand->options |= NAND_NO_SUBPAGE_WRITE;
+
+	ret = nand_ecc_choose_conf(nand, nfc->data->ecc_caps,
+				   mtd->oobsize - 2 * nsectors);
+	if (ret) {
+		dev_err(nfc->dev, "failed to ECC init\n");
+		return -EINVAL;
+	}
+
+	ret = meson_nand_bch_mode(nand);
+	if (ret)
+		return -EINVAL;
+
+	nand->ecc.mode = NAND_ECC_HW;
+	nand->ecc.write_page_raw = meson_nfc_write_page_raw;
+	nand->ecc.write_page = meson_nfc_write_page_hwecc;
+	nand->ecc.write_oob_raw = nand_write_oob_std;
+	nand->ecc.write_oob = nand_write_oob_std;
+
+	nand->ecc.read_page_raw = meson_nfc_read_page_raw;
+	nand->ecc.read_page = meson_nfc_read_page_hwecc;
+	nand->ecc.read_oob_raw = meson_nfc_read_oob_raw;
+	nand->ecc.read_oob = meson_nfc_read_oob;
+
+	if (nand->options & NAND_BUSWIDTH_16) {
+		dev_err(nfc->dev, "16bits bus width not supported");
+		return -EINVAL;
+	}
+	meson_chip_buffer_init(nand);
+	if (ret)
+		return -ENOMEM;
+
+	return ret;
+}
+
+static const struct nand_controller_ops meson_nand_controller_ops = {
+	.attach_chip = meson_nand_attach_chip,
+	.detach_chip = meson_nand_detach_chip,
+	.setup_data_interface = meson_nfc_setup_data_interface,
+	.exec_op = meson_nfc_exec_op,
+};
+
+static int
+meson_nfc_nand_chip_init(struct device *dev,
+			 struct meson_nfc *nfc, struct device_node *np)
+{
+	struct meson_nfc_nand_chip *meson_chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int ret, i;
+	u32 tmp, nsels;
+
+	if (!of_get_property(np, "reg", &nsels))
+		return -EINVAL;
+
+	nsels /= sizeof(u32);
+	if (!nsels || nsels > MAX_CE_NUM) {
+		dev_err(dev, "invalid register property size\n");
+		return -EINVAL;
+	}
+
+	meson_chip = devm_kzalloc(dev,
+				  sizeof(*meson_chip) + (nsels * sizeof(u8)),
+				  GFP_KERNEL);
+	if (!meson_chip)
+		return -ENOMEM;
+
+	meson_chip->nsels = nsels;
+
+	for (i = 0; i < nsels; i++) {
+		ret = of_property_read_u32_index(np, "reg", i, &tmp);
+		if (ret) {
+			dev_err(dev, "could not retrieve register property: %d\n",
+				ret);
+			return ret;
+		}
+
+		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
+			dev_err(dev, "CS %d already assigned\n", tmp);
+			return -EINVAL;
+		}
+	}
+
+	nand = &meson_chip->nand;
+	nand->controller = &nfc->controller;
+	nand->controller->ops = &meson_nand_controller_ops;
+	nand_set_flash_node(nand, np);
+	nand_set_controller_data(nand, nfc);
+
+	nand->options |= NAND_USE_BOUNCE_BUFFER;
+	mtd = nand_to_mtd(nand);
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = dev;
+
+	ret = nand_scan(nand, nsels);
+	if (ret)
+		return ret;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		dev_err(dev, "failed to register MTD device: %d\n", ret);
+		nand_cleanup(nand);
+		return ret;
+	}
+
+	list_add_tail(&meson_chip->node, &nfc->chips);
+
+	return 0;
+}
+
+static int meson_nfc_nand_chip_cleanup(struct meson_nfc *nfc)
+{
+	struct meson_nfc_nand_chip *meson_chip;
+	struct mtd_info *mtd;
+	int ret;
+
+	while (!list_empty(&nfc->chips)) {
+		meson_chip = list_first_entry(&nfc->chips,
+					      struct meson_nfc_nand_chip, node);
+		mtd = nand_to_mtd(&meson_chip->nand);
+		ret = mtd_device_unregister(mtd);
+		if (ret)
+			return ret;
+
+		meson_nfc_free_buffer(&meson_chip->nand);
+		nand_cleanup(&meson_chip->nand);
+		list_del(&meson_chip->node);
+	}
+
+	return 0;
+}
+
+static int meson_nfc_nand_chips_init(struct device *dev,
+				     struct meson_nfc *nfc)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *nand_np;
+	int ret;
+
+	for_each_child_of_node(np, nand_np) {
+		ret = meson_nfc_nand_chip_init(dev, nfc, nand_np);
+		if (ret) {
+			meson_nfc_nand_chip_cleanup(nfc);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static irqreturn_t meson_nfc_irq(int irq, void *id)
+{
+	struct meson_nfc *nfc = id;
+	u32 cfg;
+
+	cfg = readl(nfc->reg_base + NFC_REG_CFG);
+	if (!(cfg & NFC_RB_IRQ_EN))
+		return IRQ_NONE;
+
+	cfg &= ~(NFC_RB_IRQ_EN);
+	writel(cfg, nfc->reg_base + NFC_REG_CFG);
+
+	complete(&nfc->completion);
+	return IRQ_HANDLED;
+}
+
+static const struct meson_nfc_data meson_gxl_data = {
+	.ecc_caps = &meson_gxl_ecc_caps,
+};
+
+static const struct meson_nfc_data meson_axg_data = {
+	.ecc_caps = &meson_axg_ecc_caps,
+};
+
+static const struct of_device_id meson_nfc_id_table[] = {
+	{
+		.compatible = "amlogic,meson-gxl-nfc",
+		.data = &meson_gxl_data,
+	}, {
+		.compatible = "amlogic,meson-axg-nfc",
+		.data = &meson_axg_data,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, meson_nfc_id_table);
+
+static int meson_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct meson_nfc *nfc;
+	struct resource *res;
+	int ret, irq;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	nfc->data = of_device_get_match_data(&pdev->dev);
+	if (!nfc->data)
+		return -ENODEV;
+
+	nand_controller_init(&nfc->controller);
+	INIT_LIST_HEAD(&nfc->chips);
+
+	nfc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nfc->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->reg_base))
+		return PTR_ERR(nfc->reg_base);
+
+	nfc->reg_clk =
+		syscon_regmap_lookup_by_phandle(dev->of_node,
+						"amlogic,mmc-syscon");
+	if (IS_ERR(nfc->reg_clk)) {
+		dev_err(dev, "Failed to lookup clock base\n");
+		return PTR_ERR(nfc->reg_clk);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "no NFC IRQ resource\n");
+		return -EINVAL;
+	}
+
+	ret = meson_nfc_clk_init(nfc);
+	if (ret) {
+		dev_err(dev, "failed to initialize NAND clock\n");
+		return ret;
+	}
+
+	writel(0, nfc->reg_base + NFC_REG_CFG);
+	ret = devm_request_irq(dev, irq, meson_nfc_irq, 0, dev_name(dev), nfc);
+	if (ret) {
+		dev_err(dev, "failed to request NFC IRQ\n");
+		ret = -EINVAL;
+		goto err_clk;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set DMA mask\n");
+		goto err_clk;
+	}
+
+	platform_set_drvdata(pdev, nfc);
+
+	ret = meson_nfc_nand_chips_init(dev, nfc);
+	if (ret) {
+		dev_err(dev, "failed to init NAND chips\n");
+		goto err_clk;
+	}
+
+	return 0;
+err_clk:
+	meson_nfc_disable_clk(nfc);
+	return ret;
+}
+
+static int meson_nfc_remove(struct platform_device *pdev)
+{
+	struct meson_nfc *nfc = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = meson_nfc_nand_chip_cleanup(nfc);
+	if (ret)
+		return ret;
+
+	meson_nfc_disable_clk(nfc);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver meson_nfc_driver = {
+	.probe  = meson_nfc_probe,
+	.remove = meson_nfc_remove,
+	.driver = {
+		.name  = "meson-nand",
+		.of_match_table = meson_nfc_id_table,
+	},
+};
+module_platform_driver(meson_nfc_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Liang Yang <liang.yang@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Amlogic's Meson NAND Flash Controller driver");
-- 
1.9.1