ramips: move mt7621_nand driver to files

The patch was rejected by upstream. The mtk_nand driver should be
modified to support the mt7621 flash controller instead. As there is no
newer version to backport, or no upstream version to fix bugs, let's
move the driver to the files dir under the ramips target. This makes it
easier to make changes to the driver while waiting for mt7621 support to
land in mtk_nand.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

2 files changed, 1353 insertions, 1356 deletions

diff --git a/target/linux/ramips/files/drivers/mtd/nand/raw/mt7621_nand.c b/target/linux/ramips/files/drivers/mtd/nand/raw/mt7621_nand.c
new file mode 100644
index 0000000000..f9d617b520
--- /dev/null
+++ b/target/linux/ramips/files/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_dbg(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");
diff --git a/target/linux/ramips/patches-5.10/410-mtd-rawnand-add-driver-support-for-MT7621-nand-flash.patch b/target/linux/ramips/patches-5.10/410-mtd-rawnand-add-driver-support-for-MT7621-nand-flash.patch
index 3314013420..d0686a7051 100644
--- a/target/linux/ramips/patches-5.10/410-mtd-rawnand-add-driver-support-for-MT7621-nand-flash.patch
+++ b/target/linux/ramips/patches-5.10/410-mtd-rawnand-add-driver-support-for-MT7621-nand-flash.patch
@@ -45,1359 +45,3 @@ Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
  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");