From e84e2430ee0e483842b4ff013ae8a6e7e2fa2734 Mon Sep 17 00:00:00 2001
From: Weijie Gao <weijie.gao@mediatek.com>
Date: Wed, 1 Apr 2020 02:07:58 +0800
Subject: [PATCH 1/2] mtd: rawnand: add driver support for MT7621 nand
 flash controller

This patch adds NAND flash controller driver for MediaTek MT7621 SoC.

The NAND flash controller is similar with controllers described in
mtk_nand.c, except that the controller from MT7621 doesn't support DMA
transmission, and some registers' offset and fields are different.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
 drivers/mtd/nand/raw/Kconfig       |    8 +
 drivers/mtd/nand/raw/Makefile      |    1 +
 drivers/mtd/nand/raw/mt7621_nand.c | 1348 ++++++++++++++++++++++++++++++++++++
 3 files changed, 1357 insertions(+)
 create mode 100644 drivers/mtd/nand/raw/mt7621_nand.c

--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -387,6 +387,14 @@ config MTD_NAND_QCOM
 	  Enables support for NAND flash chips on SoCs containing the EBI2 NAND
 	  controller. This controller is found on IPQ806x SoC.
 
+config MTD_NAND_MT7621
+	tristate "MT7621 NAND controller"
+	depends on SOC_MT7621 || COMPILE_TEST
+	depends on HAS_IOMEM
+	help
+	  Enables support for NAND controller on MT7621 SoC.
+	  This driver uses PIO mode for data transmission instead of DMA mode.
+
 config MTD_NAND_MTK
 	tristate "MTK NAND controller"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_MTD_NAND_SUNXI)		+= sunxi_n
 obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
 obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
+obj-$(CONFIG_MTD_NAND_MT7621)		+= mt7621_nand.o
 obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
 obj-$(CONFIG_MTD_NAND_MXIC)		+= mxic_nand.o
 obj-$(CONFIG_MTD_NAND_TEGRA)		+= tegra_nand.o
--- /dev/null
+++ b/drivers/mtd/nand/raw/mt7621_nand.c
@@ -0,0 +1,1353 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek MT7621 NAND Flash Controller driver
+ *
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sizes.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/platform_device.h>
+#include <asm/addrspace.h>
+
+/* NFI core registers */
+#define NFI_CNFG			0x000
+#define   CNFG_OP_MODE_S		12
+#define   CNFG_OP_MODE_M		GENMASK(14, 12)
+#define     CNFG_OP_CUSTOM		6
+#define   CNFG_AUTO_FMT_EN		BIT(9)
+#define   CNFG_HW_ECC_EN		BIT(8)
+#define   CNFG_BYTE_RW			BIT(6)
+#define   CNFG_READ_MODE		BIT(1)
+
+#define NFI_PAGEFMT			0x004
+#define   PAGEFMT_FDM_ECC_S		12
+#define   PAGEFMT_FDM_ECC_M		GENMASK(15, 12)
+#define   PAGEFMT_FDM_S			8
+#define   PAGEFMT_FDM_M			GENMASK(11, 8)
+#define   PAGEFMT_SPARE_S		4
+#define   PAGEFMT_SPARE_M		GENMASK(5, 4)
+#define   PAGEFMT_PAGE_S		0
+#define   PAGEFMT_PAGE_M		GENMASK(1, 0)
+
+#define NFI_CON				0x008
+#define   CON_NFI_SEC_S			12
+#define   CON_NFI_SEC_M			GENMASK(15, 12)
+#define   CON_NFI_BWR			BIT(9)
+#define   CON_NFI_BRD			BIT(8)
+#define   CON_NFI_RST			BIT(1)
+#define   CON_FIFO_FLUSH		BIT(0)
+
+#define NFI_ACCCON			0x00c
+#define   ACCCON_POECS_S		28
+#define   ACCCON_POECS_MAX		0x0f
+#define   ACCCON_POECS_DEF		3
+#define   ACCCON_PRECS_S		22
+#define   ACCCON_PRECS_MAX		0x3f
+#define   ACCCON_PRECS_DEF		3
+#define   ACCCON_C2R_S			16
+#define   ACCCON_C2R_MAX		0x3f
+#define   ACCCON_C2R_DEF		7
+#define   ACCCON_W2R_S			12
+#define   ACCCON_W2R_MAX		0x0f
+#define   ACCCON_W2R_DEF		7
+#define   ACCCON_WH_S			8
+#define   ACCCON_WH_MAX			0x0f
+#define   ACCCON_WH_DEF			15
+#define   ACCCON_WST_S			4
+#define   ACCCON_WST_MAX		0x0f
+#define   ACCCON_WST_DEF		15
+#define   ACCCON_WST_MIN		3
+#define   ACCCON_RLT_S			0
+#define   ACCCON_RLT_MAX		0x0f
+#define   ACCCON_RLT_DEF		15
+#define   ACCCON_RLT_MIN		3
+
+#define NFI_CMD				0x020
+
+#define NFI_ADDRNOB			0x030
+#define   ADDR_ROW_NOB_S		4
+#define   ADDR_ROW_NOB_M		GENMASK(6, 4)
+#define   ADDR_COL_NOB_S		0
+#define   ADDR_COL_NOB_M		GENMASK(2, 0)
+
+#define NFI_COLADDR			0x034
+#define NFI_ROWADDR			0x038
+
+#define NFI_STRDATA			0x040
+#define   STR_DATA			BIT(0)
+
+#define NFI_CNRNB			0x044
+#define   CB2R_TIME_S			4
+#define   CB2R_TIME_M			GENMASK(7, 4)
+#define   STR_CNRNB			BIT(0)
+
+#define NFI_DATAW			0x050
+#define NFI_DATAR			0x054
+
+#define NFI_PIO_DIRDY			0x058
+#define   PIO_DIRDY			BIT(0)
+
+#define NFI_STA				0x060
+#define   STA_NFI_FSM_S			16
+#define   STA_NFI_FSM_M			GENMASK(19, 16)
+#define     STA_FSM_CUSTOM_DATA		14
+#define   STA_BUSY			BIT(8)
+#define   STA_ADDR			BIT(1)
+#define   STA_CMD			BIT(0)
+
+#define NFI_ADDRCNTR			0x070
+#define   SEC_CNTR_S			12
+#define   SEC_CNTR_M			GENMASK(15, 12)
+#define   SEC_ADDR_S			0
+#define   SEC_ADDR_M			GENMASK(9, 0)
+
+#define NFI_CSEL			0x090
+#define   CSEL_S			0
+#define   CSEL_M			GENMASK(1, 0)
+
+#define NFI_FDM0L			0x0a0
+#define NFI_FDML(n)			(0x0a0 + ((n) << 3))
+
+#define NFI_FDM0M			0x0a4
+#define NFI_FDMM(n)			(0x0a4 + ((n) << 3))
+
+#define NFI_MASTER_STA			0x210
+#define   MAS_ADDR			GENMASK(11, 9)
+#define   MAS_RD			GENMASK(8, 6)
+#define   MAS_WR			GENMASK(5, 3)
+#define   MAS_RDDLY			GENMASK(2, 0)
+
+/* ECC engine registers */
+#define ECC_ENCCON			0x000
+#define   ENC_EN			BIT(0)
+
+#define ECC_ENCCNFG			0x004
+#define   ENC_CNFG_MSG_S		16
+#define   ENC_CNFG_MSG_M		GENMASK(28, 16)
+#define   ENC_MODE_S			4
+#define   ENC_MODE_M			GENMASK(5, 4)
+#define     ENC_MODE_NFI		1
+#define   ENC_TNUM_S			0
+#define   ENC_TNUM_M			GENMASK(2, 0)
+
+#define ECC_ENCIDLE			0x00c
+#define   ENC_IDLE			BIT(0)
+
+#define ECC_DECCON			0x100
+#define   DEC_EN			BIT(0)
+
+#define ECC_DECCNFG			0x104
+#define   DEC_EMPTY_EN			BIT(31)
+#define   DEC_CS_S			16
+#define   DEC_CS_M			GENMASK(28, 16)
+#define   DEC_CON_S			12
+#define   DEC_CON_M			GENMASK(13, 12)
+#define     DEC_CON_EL			2
+#define   DEC_MODE_S			4
+#define   DEC_MODE_M			GENMASK(5, 4)
+#define     DEC_MODE_NFI		1
+#define   DEC_TNUM_S			0
+#define   DEC_TNUM_M			GENMASK(2, 0)
+
+#define ECC_DECIDLE			0x10c
+#define   DEC_IDLE			BIT(1)
+
+#define ECC_DECENUM			0x114
+#define   ERRNUM_S			2
+#define   ERRNUM_M			GENMASK(3, 0)
+
+#define ECC_DECDONE			0x118
+#define   DEC_DONE7			BIT(7)
+#define   DEC_DONE6			BIT(6)
+#define   DEC_DONE5			BIT(5)
+#define   DEC_DONE4			BIT(4)
+#define   DEC_DONE3			BIT(3)
+#define   DEC_DONE2			BIT(2)
+#define   DEC_DONE1			BIT(1)
+#define   DEC_DONE0			BIT(0)
+
+#define ECC_DECEL(n)			(0x11c + (n) * 4)
+#define   DEC_EL_ODD_S			16
+#define   DEC_EL_EVEN_S			0
+#define   DEC_EL_M			0x1fff
+#define   DEC_EL_BYTE_POS_S		3
+#define   DEC_EL_BIT_POS_M		GENMASK(2, 0)
+
+#define ECC_FDMADDR			0x13c
+
+/* ENCIDLE and DECIDLE */
+#define   ECC_IDLE			BIT(0)
+
+#define ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt) \
+	((tpoecs) << ACCCON_POECS_S | (tprecs) << ACCCON_PRECS_S | \
+	(tc2r) << ACCCON_C2R_S | (tw2r) << ACCCON_W2R_S | \
+	(twh) << ACCCON_WH_S | (twst) << ACCCON_WST_S | (trlt))
+
+#define MASTER_STA_MASK			(MAS_ADDR | MAS_RD | MAS_WR | \
+					 MAS_RDDLY)
+#define NFI_RESET_TIMEOUT		1000000
+#define NFI_CORE_TIMEOUT		500000
+#define ECC_ENGINE_TIMEOUT		500000
+
+#define ECC_SECTOR_SIZE			512
+#define ECC_PARITY_BITS			13
+
+#define NFI_FDM_SIZE		8
+
+#define MT7621_NFC_NAME			"mt7621-nand"
+
+struct mt7621_nfc {
+	struct nand_controller controller;
+	struct nand_chip nand;
+	struct clk *nfi_clk;
+	struct device *dev;
+
+	void __iomem *nfi_regs;
+	void __iomem *ecc_regs;
+
+	u32 spare_per_sector;
+};
+
+static const u16 mt7621_nfi_page_size[] = { SZ_512, SZ_2K, SZ_4K };
+static const u8 mt7621_nfi_spare_size[] = { 16, 26, 27, 28 };
+static const u8 mt7621_ecc_strength[] = { 4, 6, 8, 10, 12 };
+
+static inline u32 nfi_read32(struct mt7621_nfc *nfc, u32 reg)
+{
+	return readl(nfc->nfi_regs + reg);
+}
+
+static inline void nfi_write32(struct mt7621_nfc *nfc, u32 reg, u32 val)
+{
+	writel(val, nfc->nfi_regs + reg);
+}
+
+static inline u16 nfi_read16(struct mt7621_nfc *nfc, u32 reg)
+{
+	return readw(nfc->nfi_regs + reg);
+}
+
+static inline void nfi_write16(struct mt7621_nfc *nfc, u32 reg, u16 val)
+{
+	writew(val, nfc->nfi_regs + reg);
+}
+
+static inline void ecc_write16(struct mt7621_nfc *nfc, u32 reg, u16 val)
+{
+	writew(val, nfc->ecc_regs + reg);
+}
+
+static inline u32 ecc_read32(struct mt7621_nfc *nfc, u32 reg)
+{
+	return readl(nfc->ecc_regs + reg);
+}
+
+static inline void ecc_write32(struct mt7621_nfc *nfc, u32 reg, u32 val)
+{
+	return writel(val, nfc->ecc_regs + reg);
+}
+
+static inline u8 *oob_fdm_ptr(struct nand_chip *nand, int sect)
+{
+	return nand->oob_poi + sect * NFI_FDM_SIZE;
+}
+
+static inline u8 *oob_ecc_ptr(struct mt7621_nfc *nfc, int sect)
+{
+	struct nand_chip *nand = &nfc->nand;
+
+	return nand->oob_poi + nand->ecc.steps * NFI_FDM_SIZE +
+		sect * (nfc->spare_per_sector - NFI_FDM_SIZE);
+}
+
+static inline u8 *page_data_ptr(struct nand_chip *nand, const u8 *buf,
+				int sect)
+{
+	return (u8 *)buf + sect * nand->ecc.size;
+}
+
+static int mt7621_ecc_wait_idle(struct mt7621_nfc *nfc, u32 reg)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	ret = readw_poll_timeout_atomic(nfc->ecc_regs + reg, val,
+					val & ECC_IDLE, 10,
+					ECC_ENGINE_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "ECC engine timed out entering idle mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mt7621_ecc_decoder_wait_done(struct mt7621_nfc *nfc, u32 sect)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	ret = readw_poll_timeout_atomic(nfc->ecc_regs + ECC_DECDONE, val,
+					val & (1 << sect), 10,
+					ECC_ENGINE_TIMEOUT);
+
+	if (ret) {
+		dev_warn(dev, "ECC decoder for sector %d timed out\n",
+			 sect);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void mt7621_ecc_encoder_op(struct mt7621_nfc *nfc, bool enable)
+{
+	mt7621_ecc_wait_idle(nfc, ECC_ENCIDLE);
+	ecc_write16(nfc, ECC_ENCCON, enable ? ENC_EN : 0);
+}
+
+static void mt7621_ecc_decoder_op(struct mt7621_nfc *nfc, bool enable)
+{
+	mt7621_ecc_wait_idle(nfc, ECC_DECIDLE);
+	ecc_write16(nfc, ECC_DECCON, enable ? DEC_EN : 0);
+}
+
+static int mt7621_ecc_correct_check(struct mt7621_nfc *nfc, u8 *sector_buf,
+				   u8 *fdm_buf, u32 sect)
+{
+	struct nand_chip *nand = &nfc->nand;
+	u32 decnum, num_error_bits, fdm_end_bits;
+	u32 error_locations, error_bit_loc;
+	u32 error_byte_pos, error_bit_pos;
+	int bitflips = 0;
+	u32 i;
+
+	decnum = ecc_read32(nfc, ECC_DECENUM);
+	num_error_bits = (decnum >> (sect << ERRNUM_S)) & ERRNUM_M;
+	fdm_end_bits = (nand->ecc.size + NFI_FDM_SIZE) << 3;
+
+	if (!num_error_bits)
+		return 0;
+
+	if (num_error_bits == ERRNUM_M)
+		return -1;
+
+	for (i = 0; i < num_error_bits; i++) {
+		error_locations = ecc_read32(nfc, ECC_DECEL(i / 2));
+		error_bit_loc = (error_locations >> ((i % 2) * DEC_EL_ODD_S)) &
+				DEC_EL_M;
+		error_byte_pos = error_bit_loc >> DEC_EL_BYTE_POS_S;
+		error_bit_pos = error_bit_loc & DEC_EL_BIT_POS_M;
+
+		if (error_bit_loc < (nand->ecc.size << 3)) {
+			if (sector_buf) {
+				sector_buf[error_byte_pos] ^=
+					(1 << error_bit_pos);
+			}
+		} else if (error_bit_loc < fdm_end_bits) {
+			if (fdm_buf) {
+				fdm_buf[error_byte_pos - nand->ecc.size] ^=
+					(1 << error_bit_pos);
+			}
+		}
+
+		bitflips++;
+	}
+
+	return bitflips;
+}
+
+static int mt7621_nfc_wait_write_completion(struct mt7621_nfc *nfc,
+					    struct nand_chip *nand)
+{
+	struct device *dev = nfc->dev;
+	u16 val;
+	int ret;
+
+	ret = readw_poll_timeout_atomic(nfc->nfi_regs + NFI_ADDRCNTR, val,
+		((val & SEC_CNTR_M) >> SEC_CNTR_S) >= nand->ecc.steps, 10,
+		NFI_CORE_TIMEOUT);
+
+	if (ret) {
+		dev_warn(dev, "NFI core write operation timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
+static void mt7621_nfc_hw_reset(struct mt7621_nfc *nfc)
+{
+	u32 val;
+	int ret;
+
+	/* reset all registers and force the NFI master to terminate */
+	nfi_write16(nfc, NFI_CON, CON_FIFO_FLUSH | CON_NFI_RST);
+
+	/* wait for the master to finish the last transaction */
+	ret = readw_poll_timeout(nfc->nfi_regs + NFI_MASTER_STA, val,
+				 !(val & MASTER_STA_MASK), 50,
+				 NFI_RESET_TIMEOUT);
+	if (ret) {
+		dev_warn(nfc->dev, "Failed to reset NFI master in %dms\n",
+			 NFI_RESET_TIMEOUT);
+	}
+
+	/* ensure any status register affected by the NFI master is reset */
+	nfi_write16(nfc, NFI_CON, CON_FIFO_FLUSH | CON_NFI_RST);
+	nfi_write16(nfc, NFI_STRDATA, 0);
+}
+
+static inline void mt7621_nfc_hw_init(struct mt7621_nfc *nfc)
+{
+	u32 acccon;
+
+	/*
+	 * CNRNB: nand ready/busy register
+	 * -------------------------------
+	 * 7:4: timeout register for polling the NAND busy/ready signal
+	 * 0  : poll the status of the busy/ready signal after [7:4]*16 cycles.
+	 */
+	nfi_write16(nfc, NFI_CNRNB, CB2R_TIME_M | STR_CNRNB);
+
+	mt7621_nfc_hw_reset(nfc);
+
+	/* Apply default access timing */
+	acccon = ACCTIMING(ACCCON_POECS_DEF, ACCCON_PRECS_DEF, ACCCON_C2R_DEF,
+			   ACCCON_W2R_DEF, ACCCON_WH_DEF, ACCCON_WST_DEF,
+			   ACCCON_RLT_DEF);
+
+	nfi_write32(nfc, NFI_ACCCON, acccon);
+}
+
+static int mt7621_nfc_send_command(struct mt7621_nfc *nfc, u8 command)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_write32(nfc, NFI_CMD, command);
+
+	ret = readl_poll_timeout_atomic(nfc->nfi_regs + NFI_STA, val,
+					!(val & STA_CMD), 10,
+					NFI_CORE_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "NFI core timed out entering command mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mt7621_nfc_send_address_byte(struct mt7621_nfc *nfc, int addr)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_write32(nfc, NFI_COLADDR, addr);
+	nfi_write32(nfc, NFI_ROWADDR, 0);
+	nfi_write16(nfc, NFI_ADDRNOB, 1);
+
+	ret = readl_poll_timeout_atomic(nfc->nfi_regs + NFI_STA, val,
+					!(val & STA_ADDR), 10,
+					NFI_CORE_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "NFI core timed out entering address mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mt7621_nfc_send_address(struct mt7621_nfc *nfc, const u8 *addr,
+				   unsigned int naddrs)
+{
+	int ret;
+
+	while (naddrs) {
+		ret = mt7621_nfc_send_address_byte(nfc, *addr);
+		if (ret)
+			return ret;
+
+		addr++;
+		naddrs--;
+	}
+
+	return 0;
+}
+
+static void mt7621_nfc_wait_pio_ready(struct mt7621_nfc *nfc)
+{
+	struct device *dev = nfc->dev;
+	int ret;
+	u16 val;
+
+	ret = readw_poll_timeout_atomic(nfc->nfi_regs + NFI_PIO_DIRDY, val,
+					val & PIO_DIRDY, 10,
+					NFI_CORE_TIMEOUT);
+	if (ret < 0)
+		dev_err(dev, "NFI core PIO mode not ready\n");
+}
+
+static u32 mt7621_nfc_pio_read(struct mt7621_nfc *nfc, bool br)
+{
+	u32 reg;
+
+	/* after each byte read, the NFI_STA reg is reset by the hardware */
+	reg = (nfi_read32(nfc, NFI_STA) & STA_NFI_FSM_M) >> STA_NFI_FSM_S;
+	if (reg != STA_FSM_CUSTOM_DATA) {
+		reg = nfi_read16(nfc, NFI_CNFG);
+		reg |= CNFG_READ_MODE | CNFG_BYTE_RW;
+		if (!br)
+			reg &= ~CNFG_BYTE_RW;
+		nfi_write16(nfc, NFI_CNFG, reg);
+
+		/*
+		 * set to max sector to allow the HW to continue reading over
+		 * unaligned accesses
+		 */
+		nfi_write16(nfc, NFI_CON, CON_NFI_SEC_M | CON_NFI_BRD);
+
+		/* trigger to fetch data */
+		nfi_write16(nfc, NFI_STRDATA, STR_DATA);
+	}
+
+	mt7621_nfc_wait_pio_ready(nfc);
+
+	return nfi_read32(nfc, NFI_DATAR);
+}
+
+static void mt7621_nfc_read_data(struct mt7621_nfc *nfc, u8 *buf, u32 len)
+{
+	while (((uintptr_t)buf & 3) && len) {
+		*buf = mt7621_nfc_pio_read(nfc, true);
+		buf++;
+		len--;
+	}
+
+	while (len >= 4) {
+		*(u32 *)buf = mt7621_nfc_pio_read(nfc, false);
+		buf += 4;
+		len -= 4;
+	}
+
+	while (len) {
+		*buf = mt7621_nfc_pio_read(nfc, true);
+		buf++;
+		len--;
+	}
+}
+
+static void mt7621_nfc_read_data_discard(struct mt7621_nfc *nfc, u32 len)
+{
+	while (len >= 4) {
+		mt7621_nfc_pio_read(nfc, false);
+		len -= 4;
+	}
+
+	while (len) {
+		mt7621_nfc_pio_read(nfc, true);
+		len--;
+	}
+}
+
+static void mt7621_nfc_pio_write(struct mt7621_nfc *nfc, u32 val, bool bw)
+{
+	u32 reg;
+
+	reg = (nfi_read32(nfc, NFI_STA) & STA_NFI_FSM_M) >> STA_NFI_FSM_S;
+	if (reg != STA_FSM_CUSTOM_DATA) {
+		reg = nfi_read16(nfc, NFI_CNFG);
+		reg &= ~(CNFG_READ_MODE | CNFG_BYTE_RW);
+		if (bw)
+			reg |= CNFG_BYTE_RW;
+		nfi_write16(nfc, NFI_CNFG, reg);
+
+		nfi_write16(nfc, NFI_CON, CON_NFI_SEC_M | CON_NFI_BWR);
+		nfi_write16(nfc, NFI_STRDATA, STR_DATA);
+	}
+
+	mt7621_nfc_wait_pio_ready(nfc);
+	nfi_write32(nfc, NFI_DATAW, val);
+}
+
+static void mt7621_nfc_write_data(struct mt7621_nfc *nfc, const u8 *buf,
+				  u32 len)
+{
+	while (((uintptr_t)buf & 3) && len) {
+		mt7621_nfc_pio_write(nfc, *buf, true);
+		buf++;
+		len--;
+	}
+
+	while (len >= 4) {
+		mt7621_nfc_pio_write(nfc, *(const u32 *)buf, false);
+		buf += 4;
+		len -= 4;
+	}
+
+	while (len) {
+		mt7621_nfc_pio_write(nfc, *buf, true);
+		buf++;
+		len--;
+	}
+}
+
+static void mt7621_nfc_write_data_empty(struct mt7621_nfc *nfc, u32 len)
+{
+	while (len >= 4) {
+		mt7621_nfc_pio_write(nfc, 0xffffffff, false);
+		len -= 4;
+	}
+
+	while (len) {
+		mt7621_nfc_pio_write(nfc, 0xff, true);
+		len--;
+	}
+}
+
+static int mt7621_nfc_dev_ready(struct mt7621_nfc *nfc,
+				unsigned int timeout_ms)
+{
+	u32 val;
+
+	return readl_poll_timeout_atomic(nfc->nfi_regs + NFI_STA, val,
+					 !(val & STA_BUSY), 10,
+					 timeout_ms * 1000);
+}
+
+static int mt7621_nfc_exec_instr(struct nand_chip *nand,
+				 const struct nand_op_instr *instr)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		mt7621_nfc_hw_reset(nfc);
+		nfi_write16(nfc, NFI_CNFG, CNFG_OP_CUSTOM << CNFG_OP_MODE_S);
+		return mt7621_nfc_send_command(nfc, instr->ctx.cmd.opcode);
+	case NAND_OP_ADDR_INSTR:
+		return mt7621_nfc_send_address(nfc, instr->ctx.addr.addrs,
+					       instr->ctx.addr.naddrs);
+	case NAND_OP_DATA_IN_INSTR:
+		mt7621_nfc_read_data(nfc, instr->ctx.data.buf.in,
+				     instr->ctx.data.len);
+		return 0;
+	case NAND_OP_DATA_OUT_INSTR:
+		mt7621_nfc_write_data(nfc, instr->ctx.data.buf.out,
+				      instr->ctx.data.len);
+		return 0;
+	case NAND_OP_WAITRDY_INSTR:
+		return mt7621_nfc_dev_ready(nfc,
+					    instr->ctx.waitrdy.timeout_ms);
+	default:
+		WARN_ONCE(1, "unsupported NAND instruction type: %d\n",
+			  instr->type);
+
+		return -EINVAL;
+	}
+}
+
+static int mt7621_nfc_exec_op(struct nand_chip *nand,
+			      const struct nand_operation *op, bool check_only)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	int i, ret;
+
+	if (check_only)
+		return 0;
+
+	/* Only CS0 available */
+	nfi_write16(nfc, NFI_CSEL, 0);
+
+	for (i = 0; i < op->ninstrs; i++) {
+		ret = mt7621_nfc_exec_instr(nand, &op->instrs[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int mt7621_nfc_setup_interface(struct nand_chip *nand, int csline,
+				      const struct nand_interface_config *conf)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	const struct nand_sdr_timings *timings;
+	u32 acccon, temp, rate, tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt;
+
+	if (!nfc->nfi_clk)
+		return -ENOTSUPP;
+
+	timings = nand_get_sdr_timings(conf);
+	if (IS_ERR(timings))
+		return -ENOTSUPP;
+
+	rate = clk_get_rate(nfc->nfi_clk);
+
+	/* turn clock rate into KHZ */
+	rate /= 1000;
+
+	tpoecs = max(timings->tALH_min, timings->tCLH_min) / 1000;
+	tpoecs = DIV_ROUND_UP(tpoecs * rate, 1000000);
+	tpoecs = min_t(u32, tpoecs, ACCCON_POECS_MAX);
+
+	tprecs = max(timings->tCLS_min, timings->tALS_min) / 1000;
+	tprecs = DIV_ROUND_UP(tprecs * rate, 1000000);
+	tprecs = min_t(u32, tprecs, ACCCON_PRECS_MAX);
+
+	/* sdr interface has no tCR which means CE# low to RE# low */
+	tc2r = 0;
+
+	tw2r = timings->tWHR_min / 1000;
+	tw2r = DIV_ROUND_UP(tw2r * rate, 1000000);
+	tw2r = DIV_ROUND_UP(tw2r - 1, 2);
+	tw2r = min_t(u32, tw2r, ACCCON_W2R_MAX);
+
+	twh = max(timings->tREH_min, timings->tWH_min) / 1000;
+	twh = DIV_ROUND_UP(twh * rate, 1000000) - 1;
+	twh = min_t(u32, twh, ACCCON_WH_MAX);
+
+	/* Calculate real WE#/RE# hold time in nanosecond */
+	temp = (twh + 1) * 1000000 / rate;
+	/* nanosecond to picosecond */
+	temp *= 1000;
+
+	/*
+	 * WE# low level time should be expaned to meet WE# pulse time
+	 * and WE# cycle time at the same time.
+	 */
+	if (temp < timings->tWC_min)
+		twst = timings->tWC_min - temp;
+	else
+		twst = 0;
+	twst = max(timings->tWP_min, twst) / 1000;
+	twst = DIV_ROUND_UP(twst * rate, 1000000) - 1;
+	twst = min_t(u32, twst, ACCCON_WST_MAX);
+
+	/*
+	 * RE# low level time should be expaned to meet RE# pulse time
+	 * and RE# cycle time at the same time.
+	 */
+	if (temp < timings->tRC_min)
+		trlt = timings->tRC_min - temp;
+	else
+		trlt = 0;
+	trlt = max(trlt, timings->tRP_min) / 1000;
+	trlt = DIV_ROUND_UP(trlt * rate, 1000000) - 1;
+	trlt = min_t(u32, trlt, ACCCON_RLT_MAX);
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY) {
+		if (twst < ACCCON_WST_MIN || trlt < ACCCON_RLT_MIN)
+			return -ENOTSUPP;
+	}
+
+	acccon = ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt);
+
+	dev_info(nfc->dev, "Using programmed access timing: %08x\n", acccon);
+
+	nfi_write32(nfc, NFI_ACCCON, acccon);
+
+	return 0;
+}
+
+static int mt7621_nfc_calc_ecc_strength(struct mt7621_nfc *nfc,
+					u32 avail_ecc_bytes)
+{
+	struct nand_chip *nand = &nfc->nand;
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	u32 strength;
+	int i;
+
+	strength = avail_ecc_bytes * 8 / ECC_PARITY_BITS;
+
+	/* Find the closest supported ecc strength */
+	for (i = ARRAY_SIZE(mt7621_ecc_strength) - 1; i >= 0; i--) {
+		if (mt7621_ecc_strength[i] <= strength)
+			break;
+	}
+
+	if (unlikely(i < 0)) {
+		dev_err(nfc->dev, "OOB size (%u) is not supported\n",
+			mtd->oobsize);
+		return -EINVAL;
+	}
+
+	nand->ecc.strength = mt7621_ecc_strength[i];
+	nand->ecc.bytes =
+		DIV_ROUND_UP(nand->ecc.strength * ECC_PARITY_BITS, 8);
+
+	dev_info(nfc->dev, "ECC strength adjusted to %u bits\n",
+		 nand->ecc.strength);
+
+	return i;
+}
+
+static int mt7621_nfc_set_spare_per_sector(struct mt7621_nfc *nfc)
+{
+	struct nand_chip *nand = &nfc->nand;
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	u32 size;
+	int i;
+
+	size = nand->ecc.bytes + NFI_FDM_SIZE;
+
+	/* Find the closest supported spare size */
+	for (i = 0; i < ARRAY_SIZE(mt7621_nfi_spare_size); i++) {
+		if (mt7621_nfi_spare_size[i] >= size)
+			break;
+	}
+
+	if (unlikely(i >= ARRAY_SIZE(mt7621_nfi_spare_size))) {
+		dev_err(nfc->dev, "OOB size (%u) is not supported\n",
+			mtd->oobsize);
+		return -EINVAL;
+	}
+
+	nfc->spare_per_sector = mt7621_nfi_spare_size[i];
+
+	return i;
+}
+
+static int mt7621_nfc_ecc_init(struct mt7621_nfc *nfc)
+{
+	struct nand_chip *nand = &nfc->nand;
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	u32 spare_per_sector, encode_block_size, decode_block_size;
+	u32 ecc_enccfg, ecc_deccfg;
+	int ecc_cap;
+
+	/* Only hardware ECC mode is supported */
+	if (nand->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST) {
+		dev_err(nfc->dev, "Only hardware ECC mode is supported\n");
+		return -EINVAL;
+	}
+
+	nand->ecc.size = ECC_SECTOR_SIZE;
+	nand->ecc.steps = mtd->writesize / nand->ecc.size;
+
+	spare_per_sector = mtd->oobsize / nand->ecc.steps;
+
+	ecc_cap = mt7621_nfc_calc_ecc_strength(nfc,
+		spare_per_sector - NFI_FDM_SIZE);
+	if (ecc_cap < 0)
+		return ecc_cap;
+
+	/* Sector + FDM */
+	encode_block_size = (nand->ecc.size + NFI_FDM_SIZE) * 8;
+	ecc_enccfg = ecc_cap | (ENC_MODE_NFI << ENC_MODE_S) |
+		     (encode_block_size << ENC_CNFG_MSG_S);
+
+	/* Sector + FDM + ECC parity bits */
+	decode_block_size = ((nand->ecc.size + NFI_FDM_SIZE) * 8) +
+			    nand->ecc.strength * ECC_PARITY_BITS;
+	ecc_deccfg = ecc_cap | (DEC_MODE_NFI << DEC_MODE_S) |
+		     (decode_block_size << DEC_CS_S) |
+		     (DEC_CON_EL << DEC_CON_S) | DEC_EMPTY_EN;
+
+	mt7621_ecc_encoder_op(nfc, false);
+	ecc_write32(nfc, ECC_ENCCNFG, ecc_enccfg);
+
+	mt7621_ecc_decoder_op(nfc, false);
+	ecc_write32(nfc, ECC_DECCNFG, ecc_deccfg);
+
+	return 0;
+}
+
+static int mt7621_nfc_set_page_format(struct mt7621_nfc *nfc)
+{
+	struct nand_chip *nand = &nfc->nand;
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	int i, spare_size;
+	u32 pagefmt;
+
+	spare_size = mt7621_nfc_set_spare_per_sector(nfc);
+	if (spare_size < 0)
+		return spare_size;
+
+	for (i = 0; i < ARRAY_SIZE(mt7621_nfi_page_size); i++) {
+		if (mt7621_nfi_page_size[i] == mtd->writesize)
+			break;
+	}
+
+	if (unlikely(i >= ARRAY_SIZE(mt7621_nfi_page_size))) {
+		dev_err(nfc->dev, "Page size (%u) is not supported\n",
+			mtd->writesize);
+		return -EINVAL;
+	}
+
+	pagefmt = i | (spare_size << PAGEFMT_SPARE_S) |
+		  (NFI_FDM_SIZE << PAGEFMT_FDM_S) |
+		  (NFI_FDM_SIZE << PAGEFMT_FDM_ECC_S);
+
+	nfi_write16(nfc, NFI_PAGEFMT, pagefmt);
+
+	return 0;
+}
+
+static int mt7621_nfc_attach_chip(struct nand_chip *nand)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	int ret;
+
+	if (nand->options & NAND_BUSWIDTH_16) {
+		dev_err(nfc->dev, "16-bit buswidth is not supported");
+		return -EINVAL;
+	}
+
+	ret = mt7621_nfc_ecc_init(nfc);
+	if (ret)
+		return ret;
+
+	return mt7621_nfc_set_page_format(nfc);
+}
+
+static const struct nand_controller_ops mt7621_nfc_controller_ops = {
+	.attach_chip = mt7621_nfc_attach_chip,
+	.exec_op = mt7621_nfc_exec_op,
+	.setup_interface = mt7621_nfc_setup_interface,
+};
+
+static int mt7621_nfc_ooblayout_free(struct mtd_info *mtd, int section,
+				     struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (section >= nand->ecc.steps)
+		return -ERANGE;
+
+	oob_region->length = NFI_FDM_SIZE - 1;
+	oob_region->offset = section * NFI_FDM_SIZE + 1;
+
+	return 0;
+}
+
+static int mt7621_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
+				    struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (section)
+		return -ERANGE;
+
+	oob_region->offset = NFI_FDM_SIZE * nand->ecc.steps;
+	oob_region->length = mtd->oobsize - oob_region->offset;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops mt7621_nfc_ooblayout_ops = {
+	.free = mt7621_nfc_ooblayout_free,
+	.ecc = mt7621_nfc_ooblayout_ecc,
+};
+
+static void mt7621_nfc_write_fdm(struct mt7621_nfc *nfc)
+{
+	struct nand_chip *nand = &nfc->nand;
+	u32 vall, valm;
+	u8 *oobptr;
+	int i, j;
+
+	for (i = 0; i < nand->ecc.steps; i++) {
+		vall = 0;
+		valm = 0;
+		oobptr = oob_fdm_ptr(nand, i);
+
+		for (j = 0; j < 4; j++)
+			vall |= (u32)oobptr[j] << (j * 8);
+
+		for (j = 0; j < 4; j++)
+			valm |= (u32)oobptr[j + 4] << (j * 8);
+
+		nfi_write32(nfc, NFI_FDML(i), vall);
+		nfi_write32(nfc, NFI_FDMM(i), valm);
+	}
+}
+
+static void mt7621_nfc_read_sector_fdm(struct mt7621_nfc *nfc, u32 sect)
+{
+	struct nand_chip *nand = &nfc->nand;
+	u32 vall, valm;
+	u8 *oobptr;
+	int i;
+
+	vall = nfi_read32(nfc, NFI_FDML(sect));
+	valm = nfi_read32(nfc, NFI_FDMM(sect));
+	oobptr = oob_fdm_ptr(nand, sect);
+
+	for (i = 0; i < 4; i++)
+		oobptr[i] = (vall >> (i * 8)) & 0xff;
+
+	for (i = 0; i < 4; i++)
+		oobptr[i + 4] = (valm >> (i * 8)) & 0xff;
+}
+
+static int mt7621_nfc_read_page_hwecc(struct nand_chip *nand, uint8_t *buf,
+				      int oob_required, int page)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	int bitflips = 0;
+	int rc, i;
+
+	nand_read_page_op(nand, page, 0, NULL, 0);
+
+	nfi_write16(nfc, NFI_CNFG, (CNFG_OP_CUSTOM << CNFG_OP_MODE_S) |
+		    CNFG_READ_MODE | CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+
+	mt7621_ecc_decoder_op(nfc, true);
+
+	nfi_write16(nfc, NFI_CON,
+		    CON_NFI_BRD | (nand->ecc.steps << CON_NFI_SEC_S));
+
+	for (i = 0; i < nand->ecc.steps; i++) {
+		if (buf)
+			mt7621_nfc_read_data(nfc, page_data_ptr(nand, buf, i),
+					     nand->ecc.size);
+		else
+			mt7621_nfc_read_data_discard(nfc, nand->ecc.size);
+
+		rc = mt7621_ecc_decoder_wait_done(nfc, i);
+
+		mt7621_nfc_read_sector_fdm(nfc, i);
+
+		if (rc < 0) {
+			bitflips = -EIO;
+			continue;
+		}
+
+		rc = mt7621_ecc_correct_check(nfc,
+			buf ? page_data_ptr(nand, buf, i) : NULL,
+			oob_fdm_ptr(nand, i), i);
+
+		if (rc < 0) {
+			dev_warn(nfc->dev,
+				 "Uncorrectable ECC error at page %d.%d\n",
+				 page, i);
+			bitflips = -EBADMSG;
+			mtd->ecc_stats.failed++;
+		} else if (bitflips >= 0) {
+			bitflips += rc;
+			mtd->ecc_stats.corrected += rc;
+		}
+	}
+
+	mt7621_ecc_decoder_op(nfc, false);
+
+	nfi_write16(nfc, NFI_CON, 0);
+
+	return bitflips;
+}
+
+static int mt7621_nfc_read_page_raw(struct nand_chip *nand, uint8_t *buf,
+				    int oob_required, int page)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	int i;
+
+	nand_read_page_op(nand, page, 0, NULL, 0);
+
+	nfi_write16(nfc, NFI_CNFG, (CNFG_OP_CUSTOM << CNFG_OP_MODE_S) |
+		    CNFG_READ_MODE);
+
+	nfi_write16(nfc, NFI_CON,
+		    CON_NFI_BRD | (nand->ecc.steps << CON_NFI_SEC_S));
+
+	for (i = 0; i < nand->ecc.steps; i++) {
+		/* Read data */
+		if (buf)
+			mt7621_nfc_read_data(nfc, page_data_ptr(nand, buf, i),
+					     nand->ecc.size);
+		else
+			mt7621_nfc_read_data_discard(nfc, nand->ecc.size);
+
+		/* Read FDM */
+		mt7621_nfc_read_data(nfc, oob_fdm_ptr(nand, i), NFI_FDM_SIZE);
+
+		/* Read ECC parity data */
+		mt7621_nfc_read_data(nfc, oob_ecc_ptr(nfc, i),
+				     nfc->spare_per_sector - NFI_FDM_SIZE);
+	}
+
+	nfi_write16(nfc, NFI_CON, 0);
+
+	return 0;
+}
+
+static int mt7621_nfc_read_oob_hwecc(struct nand_chip *nand, int page)
+{
+	return mt7621_nfc_read_page_hwecc(nand, NULL, 1, page);
+}
+
+static int mt7621_nfc_read_oob_raw(struct nand_chip *nand, int page)
+{
+	return mt7621_nfc_read_page_raw(nand, NULL, 1, page);
+}
+
+static int mt7621_nfc_check_empty_page(struct nand_chip *nand, const u8 *buf)
+{
+	struct mtd_info *mtd = nand_to_mtd(nand);
+	uint32_t i, j;
+	u8 *oobptr;
+
+	if (buf) {
+		for (i = 0; i < mtd->writesize; i++)
+			if (buf[i] != 0xff)
+				return 0;
+	}
+
+	for (i = 0; i < nand->ecc.steps; i++) {
+		oobptr = oob_fdm_ptr(nand, i);
+		for (j = 0; j < NFI_FDM_SIZE; j++)
+			if (oobptr[j] != 0xff)
+				return 0;
+	}
+
+	return 1;
+}
+
+static int mt7621_nfc_write_page_hwecc(struct nand_chip *nand,
+				       const uint8_t *buf, int oob_required,
+				       int page)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	struct mtd_info *mtd = nand_to_mtd(nand);
+
+	if (mt7621_nfc_check_empty_page(nand, buf)) {
+		/*
+		 * MT7621 ECC engine always generates parity code for input
+		 * pages, even for empty pages. Doing so will write back ECC
+		 * parity code to the oob region, which means such pages will
+		 * no longer be empty pages.
+		 *
+		 * To avoid this, stop write operation if current page is an
+		 * empty page.
+		 */
+		return 0;
+	}
+
+	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
+
+	nfi_write16(nfc, NFI_CNFG, (CNFG_OP_CUSTOM << CNFG_OP_MODE_S) |
+		   CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+
+	mt7621_ecc_encoder_op(nfc, true);
+
+	mt7621_nfc_write_fdm(nfc);
+
+	nfi_write16(nfc, NFI_CON,
+		    CON_NFI_BWR | (nand->ecc.steps << CON_NFI_SEC_S));
+
+	if (buf)
+		mt7621_nfc_write_data(nfc, buf, mtd->writesize);
+	else
+		mt7621_nfc_write_data_empty(nfc, mtd->writesize);
+
+	mt7621_nfc_wait_write_completion(nfc, nand);
+
+	mt7621_ecc_encoder_op(nfc, false);
+
+	nfi_write16(nfc, NFI_CON, 0);
+
+	return nand_prog_page_end_op(nand);
+}
+
+static int mt7621_nfc_write_page_raw(struct nand_chip *nand,
+				     const uint8_t *buf, int oob_required,
+				     int page)
+{
+	struct mt7621_nfc *nfc = nand_get_controller_data(nand);
+	int i;
+
+	nand_prog_page_begin_op(nand, page, 0, NULL, 0);
+
+	nfi_write16(nfc, NFI_CNFG, (CNFG_OP_CUSTOM << CNFG_OP_MODE_S));
+
+	nfi_write16(nfc, NFI_CON,
+		    CON_NFI_BWR | (nand->ecc.steps << CON_NFI_SEC_S));
+
+	for (i = 0; i < nand->ecc.steps; i++) {
+		/* Write data */
+		if (buf)
+			mt7621_nfc_write_data(nfc, page_data_ptr(nand, buf, i),
+					      nand->ecc.size);
+		else
+			mt7621_nfc_write_data_empty(nfc, nand->ecc.size);
+
+		/* Write FDM */
+		mt7621_nfc_write_data(nfc, oob_fdm_ptr(nand, i),
+				      NFI_FDM_SIZE);
+
+		/* Write dummy ECC parity data */
+		mt7621_nfc_write_data_empty(nfc, nfc->spare_per_sector -
+					    NFI_FDM_SIZE);
+	}
+
+	mt7621_nfc_wait_write_completion(nfc, nand);
+
+	nfi_write16(nfc, NFI_CON, 0);
+
+	return nand_prog_page_end_op(nand);
+}
+
+static int mt7621_nfc_write_oob_hwecc(struct nand_chip *nand, int page)
+{
+	return mt7621_nfc_write_page_hwecc(nand, NULL, 1, page);
+}
+
+static int mt7621_nfc_write_oob_raw(struct nand_chip *nand, int page)
+{
+	return mt7621_nfc_write_page_raw(nand, NULL, 1, page);
+}
+
+static int mt7621_nfc_init_chip(struct mt7621_nfc *nfc)
+{
+	struct nand_chip *nand = &nfc->nand;
+	struct mtd_info *mtd;
+	int ret;
+
+	nand->controller = &nfc->controller;
+	nand_set_controller_data(nand, (void *)nfc);
+	nand_set_flash_node(nand, nfc->dev->of_node);
+
+	nand->options |= NAND_USES_DMA | NAND_NO_SUBPAGE_WRITE;
+	if (!nfc->nfi_clk)
+		nand->options |= NAND_KEEP_TIMINGS;
+
+	nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
+	nand->ecc.read_page = mt7621_nfc_read_page_hwecc;
+	nand->ecc.read_page_raw = mt7621_nfc_read_page_raw;
+	nand->ecc.write_page = mt7621_nfc_write_page_hwecc;
+	nand->ecc.write_page_raw = mt7621_nfc_write_page_raw;
+	nand->ecc.read_oob = mt7621_nfc_read_oob_hwecc;
+	nand->ecc.read_oob_raw = mt7621_nfc_read_oob_raw;
+	nand->ecc.write_oob = mt7621_nfc_write_oob_hwecc;
+	nand->ecc.write_oob_raw = mt7621_nfc_write_oob_raw;
+
+	mtd = nand_to_mtd(nand);
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = nfc->dev;
+	mtd->name = MT7621_NFC_NAME;
+	mtd_set_ooblayout(mtd, &mt7621_nfc_ooblayout_ops);
+
+	mt7621_nfc_hw_init(nfc);
+
+	ret = nand_scan(nand, 1);
+	if (ret)
+		return ret;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		dev_err(nfc->dev, "Failed to register MTD: %d\n", ret);
+		nand_cleanup(nand);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int mt7621_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mt7621_nfc *nfc;
+	struct resource *res;
+	int ret;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	nand_controller_init(&nfc->controller);
+	nfc->controller.ops = &mt7621_nfc_controller_ops;
+	nfc->dev = dev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nfi");
+	nfc->nfi_regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->nfi_regs)) {
+		ret = PTR_ERR(nfc->nfi_regs);
+		return ret;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ecc");
+	nfc->ecc_regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->ecc_regs)) {
+		ret = PTR_ERR(nfc->ecc_regs);
+		return ret;
+	}
+
+	nfc->nfi_clk = devm_clk_get(dev, "nfi_clk");
+	if (IS_ERR(nfc->nfi_clk)) {
+		dev_warn(dev, "nfi clk not provided\n");
+		nfc->nfi_clk = NULL;
+	} else {
+		ret = clk_prepare_enable(nfc->nfi_clk);
+		if (ret) {
+			dev_err(dev, "Failed to enable nfi core clock\n");
+			return ret;
+		}
+	}
+
+	platform_set_drvdata(pdev, nfc);
+
+	ret = mt7621_nfc_init_chip(nfc);
+	if (ret) {
+		dev_err(dev, "Failed to initialize nand chip\n");
+		goto clk_disable;
+	}
+
+	return 0;
+
+clk_disable:
+	clk_disable_unprepare(nfc->nfi_clk);
+
+	return ret;
+}
+
+static int mt7621_nfc_remove(struct platform_device *pdev)
+{
+	struct mt7621_nfc *nfc = platform_get_drvdata(pdev);
+	struct nand_chip *nand = &nfc->nand;
+	struct mtd_info *mtd = nand_to_mtd(nand);
+
+	mtd_device_unregister(mtd);
+	nand_cleanup(nand);
+	clk_disable_unprepare(nfc->nfi_clk);
+
+	return 0;
+}
+
+static const struct of_device_id mt7621_nfc_id_table[] = {
+	{ .compatible = "mediatek,mt7621-nfc" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, match);
+
+static struct platform_driver mt7621_nfc_driver = {
+	.probe = mt7621_nfc_probe,
+	.remove = mt7621_nfc_remove,
+	.driver = {
+		.name = MT7621_NFC_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = mt7621_nfc_id_table,
+	},
+};
+module_platform_driver(mt7621_nfc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Weijie Gao <weijie.gao@mediatek.com>");
+MODULE_DESCRIPTION("MediaTek MT7621 NAND Flash Controller driver");
