Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 1682 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
new file mode 100644
index 000000000..5c5c92132
--- /dev/null
+++ b/drivers/mtd/nand/raw/mtk_nand.c
@@ -0,0 +1,1682 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * MTK NAND Flash controller driver.
+ * Copyright (C) 2016 MediaTek Inc.
+ * Authors:	Xiaolei Li		<xiaolei.li@mediatek.com>
+ *		Jorge Ramirez-Ortiz	<jorge.ramirez-ortiz@linaro.org>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/mtd.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include "mtk_ecc.h"
+
+/* NAND controller register definition */
+#define NFI_CNFG		(0x00)
+#define		CNFG_AHB		BIT(0)
+#define		CNFG_READ_EN		BIT(1)
+#define		CNFG_DMA_BURST_EN	BIT(2)
+#define		CNFG_BYTE_RW		BIT(6)
+#define		CNFG_HW_ECC_EN		BIT(8)
+#define		CNFG_AUTO_FMT_EN	BIT(9)
+#define		CNFG_OP_CUST		(6 << 12)
+#define NFI_PAGEFMT		(0x04)
+#define		PAGEFMT_FDM_ECC_SHIFT	(12)
+#define		PAGEFMT_FDM_SHIFT	(8)
+#define		PAGEFMT_SEC_SEL_512	BIT(2)
+#define		PAGEFMT_512_2K		(0)
+#define		PAGEFMT_2K_4K		(1)
+#define		PAGEFMT_4K_8K		(2)
+#define		PAGEFMT_8K_16K		(3)
+/* NFI control */
+#define NFI_CON			(0x08)
+#define		CON_FIFO_FLUSH		BIT(0)
+#define		CON_NFI_RST		BIT(1)
+#define		CON_BRD			BIT(8)  /* burst  read */
+#define		CON_BWR			BIT(9)	/* burst  write */
+#define		CON_SEC_SHIFT		(12)
+/* Timming control register */
+#define NFI_ACCCON		(0x0C)
+#define NFI_INTR_EN		(0x10)
+#define		INTR_AHB_DONE_EN	BIT(6)
+#define NFI_INTR_STA		(0x14)
+#define NFI_CMD			(0x20)
+#define NFI_ADDRNOB		(0x30)
+#define NFI_COLADDR		(0x34)
+#define NFI_ROWADDR		(0x38)
+#define NFI_STRDATA		(0x40)
+#define		STAR_EN			(1)
+#define		STAR_DE			(0)
+#define NFI_CNRNB		(0x44)
+#define NFI_DATAW		(0x50)
+#define NFI_DATAR		(0x54)
+#define NFI_PIO_DIRDY		(0x58)
+#define		PIO_DI_RDY		(0x01)
+#define NFI_STA			(0x60)
+#define		STA_CMD			BIT(0)
+#define		STA_ADDR		BIT(1)
+#define		STA_BUSY		BIT(8)
+#define		STA_EMP_PAGE		BIT(12)
+#define		NFI_FSM_CUSTDATA	(0xe << 16)
+#define		NFI_FSM_MASK		(0xf << 16)
+#define NFI_ADDRCNTR		(0x70)
+#define		CNTR_MASK		GENMASK(16, 12)
+#define		ADDRCNTR_SEC_SHIFT	(12)
+#define		ADDRCNTR_SEC(val) \
+		(((val) & CNTR_MASK) >> ADDRCNTR_SEC_SHIFT)
+#define NFI_STRADDR		(0x80)
+#define NFI_BYTELEN		(0x84)
+#define NFI_CSEL		(0x90)
+#define NFI_FDML(x)		(0xA0 + (x) * sizeof(u32) * 2)
+#define NFI_FDMM(x)		(0xA4 + (x) * sizeof(u32) * 2)
+#define NFI_FDM_MAX_SIZE	(8)
+#define NFI_FDM_MIN_SIZE	(1)
+#define NFI_DEBUG_CON1		(0x220)
+#define		STROBE_MASK		GENMASK(4, 3)
+#define		STROBE_SHIFT		(3)
+#define		MAX_STROBE_DLY		(3)
+#define NFI_MASTER_STA		(0x224)
+#define		MASTER_STA_MASK		(0x0FFF)
+#define NFI_EMPTY_THRESH	(0x23C)
+
+#define MTK_NAME		"mtk-nand"
+#define KB(x)			((x) * 1024UL)
+#define MB(x)			(KB(x) * 1024UL)
+
+#define MTK_TIMEOUT		(500000)
+#define MTK_RESET_TIMEOUT	(1000000)
+#define MTK_NAND_MAX_NSELS	(2)
+#define MTK_NFC_MIN_SPARE	(16)
+#define ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt) \
+	((tpoecs) << 28 | (tprecs) << 22 | (tc2r) << 16 | \
+	(tw2r) << 12 | (twh) << 8 | (twst) << 4 | (trlt))
+
+struct mtk_nfc_caps {
+	const u8 *spare_size;
+	u8 num_spare_size;
+	u8 pageformat_spare_shift;
+	u8 nfi_clk_div;
+	u8 max_sector;
+	u32 max_sector_size;
+};
+
+struct mtk_nfc_bad_mark_ctl {
+	void (*bm_swap)(struct mtd_info *, u8 *buf, int raw);
+	u32 sec;
+	u32 pos;
+};
+
+/*
+ * FDM: region used to store free OOB data
+ */
+struct mtk_nfc_fdm {
+	u32 reg_size;
+	u32 ecc_size;
+};
+
+struct mtk_nfc_nand_chip {
+	struct list_head node;
+	struct nand_chip nand;
+
+	struct mtk_nfc_bad_mark_ctl bad_mark;
+	struct mtk_nfc_fdm fdm;
+	u32 spare_per_sector;
+
+	int nsels;
+	u8 sels[];
+	/* nothing after this field */
+};
+
+struct mtk_nfc_clk {
+	struct clk *nfi_clk;
+	struct clk *pad_clk;
+};
+
+struct mtk_nfc {
+	struct nand_controller controller;
+	struct mtk_ecc_config ecc_cfg;
+	struct mtk_nfc_clk clk;
+	struct mtk_ecc *ecc;
+
+	struct device *dev;
+	const struct mtk_nfc_caps *caps;
+	void __iomem *regs;
+
+	struct completion done;
+	struct list_head chips;
+
+	u8 *buffer;
+
+	unsigned long assigned_cs;
+};
+
+/*
+ * supported spare size of each IP.
+ * order should be the same with the spare size bitfiled defination of
+ * register NFI_PAGEFMT.
+ */
+static const u8 spare_size_mt2701[] = {
+	16, 26, 27, 28, 32, 36, 40, 44,	48, 49, 50, 51, 52, 62, 63, 64
+};
+
+static const u8 spare_size_mt2712[] = {
+	16, 26, 27, 28, 32, 36, 40, 44, 48, 49, 50, 51, 52, 62, 61, 63, 64, 67,
+	74
+};
+
+static const u8 spare_size_mt7622[] = {
+	16, 26, 27, 28
+};
+
+static inline struct mtk_nfc_nand_chip *to_mtk_nand(struct nand_chip *nand)
+{
+	return container_of(nand, struct mtk_nfc_nand_chip, nand);
+}
+
+static inline u8 *data_ptr(struct nand_chip *chip, const u8 *p, int i)
+{
+	return (u8 *)p + i * chip->ecc.size;
+}
+
+static inline u8 *oob_ptr(struct nand_chip *chip, int i)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u8 *poi;
+
+	/* map the sector's FDM data to free oob:
+	 * the beginning of the oob area stores the FDM data of bad mark sectors
+	 */
+
+	if (i < mtk_nand->bad_mark.sec)
+		poi = chip->oob_poi + (i + 1) * mtk_nand->fdm.reg_size;
+	else if (i == mtk_nand->bad_mark.sec)
+		poi = chip->oob_poi;
+	else
+		poi = chip->oob_poi + i * mtk_nand->fdm.reg_size;
+
+	return poi;
+}
+
+static inline int mtk_data_len(struct nand_chip *chip)
+{
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+
+	return chip->ecc.size + mtk_nand->spare_per_sector;
+}
+
+static inline u8 *mtk_data_ptr(struct nand_chip *chip,  int i)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	return nfc->buffer + i * mtk_data_len(chip);
+}
+
+static inline u8 *mtk_oob_ptr(struct nand_chip *chip, int i)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	return nfc->buffer + i * mtk_data_len(chip) + chip->ecc.size;
+}
+
+static inline void nfi_writel(struct mtk_nfc *nfc, u32 val, u32 reg)
+{
+	writel(val, nfc->regs + reg);
+}
+
+static inline void nfi_writew(struct mtk_nfc *nfc, u16 val, u32 reg)
+{
+	writew(val, nfc->regs + reg);
+}
+
+static inline void nfi_writeb(struct mtk_nfc *nfc, u8 val, u32 reg)
+{
+	writeb(val, nfc->regs + reg);
+}
+
+static inline u32 nfi_readl(struct mtk_nfc *nfc, u32 reg)
+{
+	return readl_relaxed(nfc->regs + reg);
+}
+
+static inline u16 nfi_readw(struct mtk_nfc *nfc, u32 reg)
+{
+	return readw_relaxed(nfc->regs + reg);
+}
+
+static inline u8 nfi_readb(struct mtk_nfc *nfc, u32 reg)
+{
+	return readb_relaxed(nfc->regs + reg);
+}
+
+static void mtk_nfc_hw_reset(struct mtk_nfc *nfc)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	/* reset all registers and force the NFI master to terminate */
+	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
+
+	/* wait for the master to finish the last transaction */
+	ret = readl_poll_timeout(nfc->regs + NFI_MASTER_STA, val,
+				 !(val & MASTER_STA_MASK), 50,
+				 MTK_RESET_TIMEOUT);
+	if (ret)
+		dev_warn(dev, "master active in reset [0x%x] = 0x%x\n",
+			 NFI_MASTER_STA, val);
+
+	/* ensure any status register affected by the NFI master is reset */
+	nfi_writel(nfc, CON_FIFO_FLUSH | CON_NFI_RST, NFI_CON);
+	nfi_writew(nfc, STAR_DE, NFI_STRDATA);
+}
+
+static int mtk_nfc_send_command(struct mtk_nfc *nfc, u8 command)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_writel(nfc, command, NFI_CMD);
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
+					!(val & STA_CMD), 10,  MTK_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "nfi core timed out entering command mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_send_address(struct mtk_nfc *nfc, int addr)
+{
+	struct device *dev = nfc->dev;
+	u32 val;
+	int ret;
+
+	nfi_writel(nfc, addr, NFI_COLADDR);
+	nfi_writel(nfc, 0, NFI_ROWADDR);
+	nfi_writew(nfc, 1, NFI_ADDRNOB);
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_STA, val,
+					!(val & STA_ADDR), 10, MTK_TIMEOUT);
+	if (ret) {
+		dev_warn(dev, "nfi core timed out entering address mode\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int mtk_nfc_hw_runtime_config(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 fmt, spare, i;
+
+	if (!mtd->writesize)
+		return 0;
+
+	spare = mtk_nand->spare_per_sector;
+
+	switch (mtd->writesize) {
+	case 512:
+		fmt = PAGEFMT_512_2K | PAGEFMT_SEC_SEL_512;
+		break;
+	case KB(2):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_2K_4K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_512_2K;
+		break;
+	case KB(4):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_4K_8K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_2K_4K;
+		break;
+	case KB(8):
+		if (chip->ecc.size == 512)
+			fmt = PAGEFMT_8K_16K | PAGEFMT_SEC_SEL_512;
+		else
+			fmt = PAGEFMT_4K_8K;
+		break;
+	case KB(16):
+		fmt = PAGEFMT_8K_16K;
+		break;
+	default:
+		dev_err(nfc->dev, "invalid page len: %d\n", mtd->writesize);
+		return -EINVAL;
+	}
+
+	/*
+	 * the hardware will double the value for this eccsize, so we need to
+	 * halve it
+	 */
+	if (chip->ecc.size == 1024)
+		spare >>= 1;
+
+	for (i = 0; i < nfc->caps->num_spare_size; i++) {
+		if (nfc->caps->spare_size[i] == spare)
+			break;
+	}
+
+	if (i == nfc->caps->num_spare_size) {
+		dev_err(nfc->dev, "invalid spare size %d\n", spare);
+		return -EINVAL;
+	}
+
+	fmt |= i << nfc->caps->pageformat_spare_shift;
+
+	fmt |= mtk_nand->fdm.reg_size << PAGEFMT_FDM_SHIFT;
+	fmt |= mtk_nand->fdm.ecc_size << PAGEFMT_FDM_ECC_SHIFT;
+	nfi_writel(nfc, fmt, NFI_PAGEFMT);
+
+	nfc->ecc_cfg.strength = chip->ecc.strength;
+	nfc->ecc_cfg.len = chip->ecc.size + mtk_nand->fdm.ecc_size;
+
+	return 0;
+}
+
+static inline void mtk_nfc_wait_ioready(struct mtk_nfc *nfc)
+{
+	int rc;
+	u8 val;
+
+	rc = readb_poll_timeout_atomic(nfc->regs + NFI_PIO_DIRDY, val,
+				       val & PIO_DI_RDY, 10, MTK_TIMEOUT);
+	if (rc < 0)
+		dev_err(nfc->dev, "data not ready\n");
+}
+
+static inline u8 mtk_nfc_read_byte(struct nand_chip *chip)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 reg;
+
+	/* after each byte read, the NFI_STA reg is reset by the hardware */
+	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
+	if (reg != NFI_FSM_CUSTDATA) {
+		reg = nfi_readw(nfc, NFI_CNFG);
+		reg |= CNFG_BYTE_RW | CNFG_READ_EN;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		/*
+		 * set to max sector to allow the HW to continue reading over
+		 * unaligned accesses
+		 */
+		reg = (nfc->caps->max_sector << CON_SEC_SHIFT) | CON_BRD;
+		nfi_writel(nfc, reg, NFI_CON);
+
+		/* trigger to fetch data */
+		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+	}
+
+	mtk_nfc_wait_ioready(nfc);
+
+	return nfi_readb(nfc, NFI_DATAR);
+}
+
+static void mtk_nfc_read_buf(struct nand_chip *chip, u8 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		buf[i] = mtk_nfc_read_byte(chip);
+}
+
+static void mtk_nfc_write_byte(struct nand_chip *chip, u8 byte)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	u32 reg;
+
+	reg = nfi_readl(nfc, NFI_STA) & NFI_FSM_MASK;
+
+	if (reg != NFI_FSM_CUSTDATA) {
+		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_BYTE_RW;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		reg = nfc->caps->max_sector << CON_SEC_SHIFT | CON_BWR;
+		nfi_writel(nfc, reg, NFI_CON);
+
+		nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+	}
+
+	mtk_nfc_wait_ioready(nfc);
+	nfi_writeb(nfc, byte, NFI_DATAW);
+}
+
+static void mtk_nfc_write_buf(struct nand_chip *chip, const u8 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		mtk_nfc_write_byte(chip, buf[i]);
+}
+
+static int mtk_nfc_exec_instr(struct nand_chip *chip,
+			      const struct nand_op_instr *instr)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	unsigned int i;
+	u32 status;
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		mtk_nfc_send_command(nfc, instr->ctx.cmd.opcode);
+		return 0;
+	case NAND_OP_ADDR_INSTR:
+		for (i = 0; i < instr->ctx.addr.naddrs; i++)
+			mtk_nfc_send_address(nfc, instr->ctx.addr.addrs[i]);
+		return 0;
+	case NAND_OP_DATA_IN_INSTR:
+		mtk_nfc_read_buf(chip, instr->ctx.data.buf.in,
+				 instr->ctx.data.len);
+		return 0;
+	case NAND_OP_DATA_OUT_INSTR:
+		mtk_nfc_write_buf(chip, instr->ctx.data.buf.out,
+				  instr->ctx.data.len);
+		return 0;
+	case NAND_OP_WAITRDY_INSTR:
+		return readl_poll_timeout(nfc->regs + NFI_STA, status,
+					  !(status & STA_BUSY), 20,
+					  instr->ctx.waitrdy.timeout_ms * 1000);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static void mtk_nfc_select_target(struct nand_chip *nand, unsigned int cs)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(nand);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(nand);
+
+	mtk_nfc_hw_runtime_config(nand_to_mtd(nand));
+
+	nfi_writel(nfc, mtk_nand->sels[cs], NFI_CSEL);
+}
+
+static int mtk_nfc_exec_op(struct nand_chip *chip,
+			   const struct nand_operation *op,
+			   bool check_only)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	unsigned int i;
+	int ret = 0;
+
+	if (check_only)
+		return 0;
+
+	mtk_nfc_hw_reset(nfc);
+	nfi_writew(nfc, CNFG_OP_CUST, NFI_CNFG);
+	mtk_nfc_select_target(chip, op->cs);
+
+	for (i = 0; i < op->ninstrs; i++) {
+		ret = mtk_nfc_exec_instr(chip, &op->instrs[i]);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static int mtk_nfc_setup_interface(struct nand_chip *chip, int csline,
+				   const struct nand_interface_config *conf)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	const struct nand_sdr_timings *timings;
+	u32 rate, tpoecs, tprecs, tc2r, tw2r, twh, twst = 0, trlt = 0;
+	u32 temp, tsel = 0;
+
+	timings = nand_get_sdr_timings(conf);
+	if (IS_ERR(timings))
+		return -ENOTSUPP;
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	rate = clk_get_rate(nfc->clk.nfi_clk);
+	/* There is a frequency divider in some IPs */
+	rate /= nfc->caps->nfi_clk_div;
+
+	/* turn clock rate into KHZ */
+	rate /= 1000;
+
+	tpoecs = max(timings->tALH_min, timings->tCLH_min) / 1000;
+	tpoecs = DIV_ROUND_UP(tpoecs * rate, 1000000);
+	tpoecs &= 0xf;
+
+	tprecs = max(timings->tCLS_min, timings->tALS_min) / 1000;
+	tprecs = DIV_ROUND_UP(tprecs * rate, 1000000);
+	tprecs &= 0x3f;
+
+	/* 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 &= 0xf;
+
+	twh = max(timings->tREH_min, timings->tWH_min) / 1000;
+	twh = DIV_ROUND_UP(twh * rate, 1000000) - 1;
+	twh &= 0xf;
+
+	/* 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;
+	twst = max(timings->tWP_min, twst) / 1000;
+	twst = DIV_ROUND_UP(twst * rate, 1000000) - 1;
+	twst &= 0xf;
+
+	/*
+	 * 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;
+	trlt = max(trlt, timings->tRP_min) / 1000;
+	trlt = DIV_ROUND_UP(trlt * rate, 1000000) - 1;
+	trlt &= 0xf;
+
+	/* Calculate RE# pulse time in nanosecond. */
+	temp = (trlt + 1) * 1000000 / rate;
+	/* nanosecond to picosecond */
+	temp *= 1000;
+	/*
+	 * If RE# access time is bigger than RE# pulse time,
+	 * delay sampling data timing.
+	 */
+	if (temp < timings->tREA_max) {
+		tsel = timings->tREA_max / 1000;
+		tsel = DIV_ROUND_UP(tsel * rate, 1000000);
+		tsel -= (trlt + 1);
+		if (tsel > MAX_STROBE_DLY) {
+			trlt += tsel - MAX_STROBE_DLY;
+			tsel = MAX_STROBE_DLY;
+		}
+	}
+	temp = nfi_readl(nfc, NFI_DEBUG_CON1);
+	temp &= ~STROBE_MASK;
+	temp |= tsel << STROBE_SHIFT;
+	nfi_writel(nfc, temp, NFI_DEBUG_CON1);
+
+	/*
+	 * ACCON: access timing control register
+	 * -------------------------------------
+	 * 31:28: tpoecs, minimum required time for CS post pulling down after
+	 *        accessing the device
+	 * 27:22: tprecs, minimum required time for CS pre pulling down before
+	 *        accessing the device
+	 * 21:16: tc2r, minimum required time from NCEB low to NREB low
+	 * 15:12: tw2r, minimum required time from NWEB high to NREB low.
+	 * 11:08: twh, write enable hold time
+	 * 07:04: twst, write wait states
+	 * 03:00: trlt, read wait states
+	 */
+	trlt = ACCTIMING(tpoecs, tprecs, tc2r, tw2r, twh, twst, trlt);
+	nfi_writel(nfc, trlt, NFI_ACCCON);
+
+	return 0;
+}
+
+static int mtk_nfc_sector_encode(struct nand_chip *chip, u8 *data)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	int size = chip->ecc.size + mtk_nand->fdm.reg_size;
+
+	nfc->ecc_cfg.mode = ECC_DMA_MODE;
+	nfc->ecc_cfg.op = ECC_ENCODE;
+
+	return mtk_ecc_encode(nfc->ecc, &nfc->ecc_cfg, data, size);
+}
+
+static void mtk_nfc_no_bad_mark_swap(struct mtd_info *a, u8 *b, int c)
+{
+	/* nop */
+}
+
+static void mtk_nfc_bad_mark_swap(struct mtd_info *mtd, u8 *buf, int raw)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *nand = to_mtk_nand(chip);
+	u32 bad_pos = nand->bad_mark.pos;
+
+	if (raw)
+		bad_pos += nand->bad_mark.sec * mtk_data_len(chip);
+	else
+		bad_pos += nand->bad_mark.sec * chip->ecc.size;
+
+	swap(chip->oob_poi[0], buf[bad_pos]);
+}
+
+static int mtk_nfc_format_subpage(struct mtd_info *mtd, u32 offset,
+				  u32 len, const u8 *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 start, end;
+	int i, ret;
+
+	start = offset / chip->ecc.size;
+	end = DIV_ROUND_UP(offset + len, chip->ecc.size);
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	for (i = 0; i < chip->ecc.steps; i++) {
+		memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
+		       chip->ecc.size);
+
+		if (start > i || i >= end)
+			continue;
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
+
+		/* program the CRC back to the OOB */
+		ret = mtk_nfc_sector_encode(chip, mtk_data_ptr(chip, i));
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void mtk_nfc_format_page(struct mtd_info *mtd, const u8 *buf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 i;
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	for (i = 0; i < chip->ecc.steps; i++) {
+		if (buf)
+			memcpy(mtk_data_ptr(chip, i), data_ptr(chip, buf, i),
+			       chip->ecc.size);
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		memcpy(mtk_oob_ptr(chip, i), oob_ptr(chip, i), fdm->reg_size);
+	}
+}
+
+static inline void mtk_nfc_read_fdm(struct nand_chip *chip, u32 start,
+				    u32 sectors)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 vall, valm;
+	u8 *oobptr;
+	int i, j;
+
+	for (i = 0; i < sectors; i++) {
+		oobptr = oob_ptr(chip, start + i);
+		vall = nfi_readl(nfc, NFI_FDML(i));
+		valm = nfi_readl(nfc, NFI_FDMM(i));
+
+		for (j = 0; j < fdm->reg_size; j++)
+			oobptr[j] = (j >= 4 ? valm : vall) >> ((j % 4) * 8);
+	}
+}
+
+static inline void mtk_nfc_write_fdm(struct nand_chip *chip)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 vall, valm;
+	u8 *oobptr;
+	int i, j;
+
+	for (i = 0; i < chip->ecc.steps; i++) {
+		oobptr = oob_ptr(chip, i);
+		vall = 0;
+		valm = 0;
+		for (j = 0; j < 8; j++) {
+			if (j < 4)
+				vall |= (j < fdm->reg_size ? oobptr[j] : 0xff)
+						<< (j * 8);
+			else
+				valm |= (j < fdm->reg_size ? oobptr[j] : 0xff)
+						<< ((j - 4) * 8);
+		}
+		nfi_writel(nfc, vall, NFI_FDML(i));
+		nfi_writel(nfc, valm, NFI_FDMM(i));
+	}
+}
+
+static int mtk_nfc_do_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+				 const u8 *buf, int page, int len)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct device *dev = nfc->dev;
+	dma_addr_t addr;
+	u32 reg;
+	int ret;
+
+	addr = dma_map_single(dev, (void *)buf, len, DMA_TO_DEVICE);
+	ret = dma_mapping_error(nfc->dev, addr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AHB | CNFG_DMA_BURST_EN;
+	nfi_writew(nfc, reg, NFI_CNFG);
+
+	nfi_writel(nfc, chip->ecc.steps << CON_SEC_SHIFT, NFI_CON);
+	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
+	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
+
+	init_completion(&nfc->done);
+
+	reg = nfi_readl(nfc, NFI_CON) | CON_BWR;
+	nfi_writel(nfc, reg, NFI_CON);
+	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+
+	ret = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
+	if (!ret) {
+		dev_err(dev, "program ahb done timeout\n");
+		nfi_writew(nfc, 0, NFI_INTR_EN);
+		ret = -ETIMEDOUT;
+		goto timeout;
+	}
+
+	ret = readl_poll_timeout_atomic(nfc->regs + NFI_ADDRCNTR, reg,
+					ADDRCNTR_SEC(reg) >= chip->ecc.steps,
+					10, MTK_TIMEOUT);
+	if (ret)
+		dev_err(dev, "hwecc write timeout\n");
+
+timeout:
+
+	dma_unmap_single(nfc->dev, addr, len, DMA_TO_DEVICE);
+	nfi_writel(nfc, 0, NFI_CON);
+
+	return ret;
+}
+
+static int mtk_nfc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
+			      const u8 *buf, int page, int raw)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	size_t len;
+	const u8 *bufpoi;
+	u32 reg;
+	int ret;
+
+	mtk_nfc_select_target(chip, chip->cur_cs);
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
+	if (!raw) {
+		/* OOB => FDM: from register,  ECC: from HW */
+		reg = nfi_readw(nfc, NFI_CNFG) | CNFG_AUTO_FMT_EN;
+		nfi_writew(nfc, reg | CNFG_HW_ECC_EN, NFI_CNFG);
+
+		nfc->ecc_cfg.op = ECC_ENCODE;
+		nfc->ecc_cfg.mode = ECC_NFI_MODE;
+		ret = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
+		if (ret) {
+			/* clear NFI config */
+			reg = nfi_readw(nfc, NFI_CNFG);
+			reg &= ~(CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+			nfi_writew(nfc, reg, NFI_CNFG);
+
+			return ret;
+		}
+
+		memcpy(nfc->buffer, buf, mtd->writesize);
+		mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, raw);
+		bufpoi = nfc->buffer;
+
+		/* write OOB into the FDM registers (OOB area in MTK NAND) */
+		mtk_nfc_write_fdm(chip);
+	} else {
+		bufpoi = buf;
+	}
+
+	len = mtd->writesize + (raw ? mtd->oobsize : 0);
+	ret = mtk_nfc_do_write_page(mtd, chip, bufpoi, page, len);
+
+	if (!raw)
+		mtk_ecc_disable(nfc->ecc);
+
+	if (ret)
+		return ret;
+
+	return nand_prog_page_end_op(chip);
+}
+
+static int mtk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
+				    int oob_on, int page)
+{
+	return mtk_nfc_write_page(nand_to_mtd(chip), chip, buf, page, 0);
+}
+
+static int mtk_nfc_write_page_raw(struct nand_chip *chip, const u8 *buf,
+				  int oob_on, int pg)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+
+	mtk_nfc_format_page(mtd, buf);
+	return mtk_nfc_write_page(mtd, chip, nfc->buffer, pg, 1);
+}
+
+static int mtk_nfc_write_subpage_hwecc(struct nand_chip *chip, u32 offset,
+				       u32 data_len, const u8 *buf,
+				       int oob_on, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	int ret;
+
+	ret = mtk_nfc_format_subpage(mtd, offset, data_len, buf);
+	if (ret < 0)
+		return ret;
+
+	/* use the data in the private buffer (now with FDM and CRC) */
+	return mtk_nfc_write_page(mtd, chip, nfc->buffer, page, 1);
+}
+
+static int mtk_nfc_write_oob_std(struct nand_chip *chip, int page)
+{
+	return mtk_nfc_write_page_raw(chip, NULL, 1, page);
+}
+
+static int mtk_nfc_update_ecc_stats(struct mtd_info *mtd, u8 *buf, u32 start,
+				    u32 sectors)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_ecc_stats stats;
+	u32 reg_size = mtk_nand->fdm.reg_size;
+	int rc, i;
+
+	rc = nfi_readl(nfc, NFI_STA) & STA_EMP_PAGE;
+	if (rc) {
+		memset(buf, 0xff, sectors * chip->ecc.size);
+		for (i = 0; i < sectors; i++)
+			memset(oob_ptr(chip, start + i), 0xff, reg_size);
+		return 0;
+	}
+
+	mtk_ecc_get_stats(nfc->ecc, &stats, sectors);
+	mtd->ecc_stats.corrected += stats.corrected;
+	mtd->ecc_stats.failed += stats.failed;
+
+	return stats.bitflips;
+}
+
+static int mtk_nfc_read_subpage(struct mtd_info *mtd, struct nand_chip *chip,
+				u32 data_offs, u32 readlen,
+				u8 *bufpoi, int page, int raw)
+{
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u32 spare = mtk_nand->spare_per_sector;
+	u32 column, sectors, start, end, reg;
+	dma_addr_t addr;
+	int bitflips = 0;
+	size_t len;
+	u8 *buf;
+	int rc;
+
+	mtk_nfc_select_target(chip, chip->cur_cs);
+	start = data_offs / chip->ecc.size;
+	end = DIV_ROUND_UP(data_offs + readlen, chip->ecc.size);
+
+	sectors = end - start;
+	column = start * (chip->ecc.size + spare);
+
+	len = sectors * chip->ecc.size + (raw ? sectors * spare : 0);
+	buf = bufpoi + start * chip->ecc.size;
+
+	nand_read_page_op(chip, page, column, NULL, 0);
+
+	addr = dma_map_single(nfc->dev, buf, len, DMA_FROM_DEVICE);
+	rc = dma_mapping_error(nfc->dev, addr);
+	if (rc) {
+		dev_err(nfc->dev, "dma mapping error\n");
+
+		return -EINVAL;
+	}
+
+	reg = nfi_readw(nfc, NFI_CNFG);
+	reg |= CNFG_READ_EN | CNFG_DMA_BURST_EN | CNFG_AHB;
+	if (!raw) {
+		reg |= CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN;
+		nfi_writew(nfc, reg, NFI_CNFG);
+
+		nfc->ecc_cfg.mode = ECC_NFI_MODE;
+		nfc->ecc_cfg.sectors = sectors;
+		nfc->ecc_cfg.op = ECC_DECODE;
+		rc = mtk_ecc_enable(nfc->ecc, &nfc->ecc_cfg);
+		if (rc) {
+			dev_err(nfc->dev, "ecc enable\n");
+			/* clear NFI_CNFG */
+			reg &= ~(CNFG_DMA_BURST_EN | CNFG_AHB | CNFG_READ_EN |
+				CNFG_AUTO_FMT_EN | CNFG_HW_ECC_EN);
+			nfi_writew(nfc, reg, NFI_CNFG);
+			dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
+
+			return rc;
+		}
+	} else {
+		nfi_writew(nfc, reg, NFI_CNFG);
+	}
+
+	nfi_writel(nfc, sectors << CON_SEC_SHIFT, NFI_CON);
+	nfi_writew(nfc, INTR_AHB_DONE_EN, NFI_INTR_EN);
+	nfi_writel(nfc, lower_32_bits(addr), NFI_STRADDR);
+
+	init_completion(&nfc->done);
+	reg = nfi_readl(nfc, NFI_CON) | CON_BRD;
+	nfi_writel(nfc, reg, NFI_CON);
+	nfi_writew(nfc, STAR_EN, NFI_STRDATA);
+
+	rc = wait_for_completion_timeout(&nfc->done, msecs_to_jiffies(500));
+	if (!rc)
+		dev_warn(nfc->dev, "read ahb/dma done timeout\n");
+
+	rc = readl_poll_timeout_atomic(nfc->regs + NFI_BYTELEN, reg,
+				       ADDRCNTR_SEC(reg) >= sectors, 10,
+				       MTK_TIMEOUT);
+	if (rc < 0) {
+		dev_err(nfc->dev, "subpage done timeout\n");
+		bitflips = -EIO;
+	} else if (!raw) {
+		rc = mtk_ecc_wait_done(nfc->ecc, ECC_DECODE);
+		bitflips = rc < 0 ? -ETIMEDOUT :
+			mtk_nfc_update_ecc_stats(mtd, buf, start, sectors);
+		mtk_nfc_read_fdm(chip, start, sectors);
+	}
+
+	dma_unmap_single(nfc->dev, addr, len, DMA_FROM_DEVICE);
+
+	if (raw)
+		goto done;
+
+	mtk_ecc_disable(nfc->ecc);
+
+	if (clamp(mtk_nand->bad_mark.sec, start, end) == mtk_nand->bad_mark.sec)
+		mtk_nand->bad_mark.bm_swap(mtd, bufpoi, raw);
+done:
+	nfi_writel(nfc, 0, NFI_CON);
+
+	return bitflips;
+}
+
+static int mtk_nfc_read_subpage_hwecc(struct nand_chip *chip, u32 off,
+				      u32 len, u8 *p, int pg)
+{
+	return mtk_nfc_read_subpage(nand_to_mtd(chip), chip, off, len, p, pg,
+				    0);
+}
+
+static int mtk_nfc_read_page_hwecc(struct nand_chip *chip, u8 *p, int oob_on,
+				   int pg)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+
+	return mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, p, pg, 0);
+}
+
+static int mtk_nfc_read_page_raw(struct nand_chip *chip, u8 *buf, int oob_on,
+				 int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	int i, ret;
+
+	memset(nfc->buffer, 0xff, mtd->writesize + mtd->oobsize);
+	ret = mtk_nfc_read_subpage(mtd, chip, 0, mtd->writesize, nfc->buffer,
+				   page, 1);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < chip->ecc.steps; i++) {
+		memcpy(oob_ptr(chip, i), mtk_oob_ptr(chip, i), fdm->reg_size);
+
+		if (i == mtk_nand->bad_mark.sec)
+			mtk_nand->bad_mark.bm_swap(mtd, nfc->buffer, 1);
+
+		if (buf)
+			memcpy(data_ptr(chip, buf, i), mtk_data_ptr(chip, i),
+			       chip->ecc.size);
+	}
+
+	return ret;
+}
+
+static int mtk_nfc_read_oob_std(struct nand_chip *chip, int page)
+{
+	return mtk_nfc_read_page_raw(chip, NULL, 1, page);
+}
+
+static inline void mtk_nfc_hw_init(struct mtk_nfc *nfc)
+{
+	/*
+	 * 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_writew(nfc, 0xf1, NFI_CNRNB);
+	nfi_writel(nfc, PAGEFMT_8K_16K, NFI_PAGEFMT);
+
+	mtk_nfc_hw_reset(nfc);
+
+	nfi_readl(nfc, NFI_INTR_STA);
+	nfi_writel(nfc, 0, NFI_INTR_EN);
+}
+
+static irqreturn_t mtk_nfc_irq(int irq, void *id)
+{
+	struct mtk_nfc *nfc = id;
+	u16 sta, ien;
+
+	sta = nfi_readw(nfc, NFI_INTR_STA);
+	ien = nfi_readw(nfc, NFI_INTR_EN);
+
+	if (!(sta & ien))
+		return IRQ_NONE;
+
+	nfi_writew(nfc, ~sta & ien, NFI_INTR_EN);
+	complete(&nfc->done);
+
+	return IRQ_HANDLED;
+}
+
+static int mtk_nfc_enable_clk(struct device *dev, struct mtk_nfc_clk *clk)
+{
+	int ret;
+
+	ret = clk_prepare_enable(clk->nfi_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable nfi clk\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(clk->pad_clk);
+	if (ret) {
+		dev_err(dev, "failed to enable pad clk\n");
+		clk_disable_unprepare(clk->nfi_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mtk_nfc_disable_clk(struct mtk_nfc_clk *clk)
+{
+	clk_disable_unprepare(clk->nfi_clk);
+	clk_disable_unprepare(clk->pad_clk);
+}
+
+static int mtk_nfc_ooblayout_free(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	struct mtk_nfc_fdm *fdm = &mtk_nand->fdm;
+	u32 eccsteps;
+
+	eccsteps = mtd->writesize / chip->ecc.size;
+
+	if (section >= eccsteps)
+		return -ERANGE;
+
+	oob_region->length = fdm->reg_size - fdm->ecc_size;
+	oob_region->offset = section * fdm->reg_size + fdm->ecc_size;
+
+	return 0;
+}
+
+static int mtk_nfc_ooblayout_ecc(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *oob_region)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	u32 eccsteps;
+
+	if (section)
+		return -ERANGE;
+
+	eccsteps = mtd->writesize / chip->ecc.size;
+	oob_region->offset = mtk_nand->fdm.reg_size * eccsteps;
+	oob_region->length = mtd->oobsize - oob_region->offset;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops mtk_nfc_ooblayout_ops = {
+	.free = mtk_nfc_ooblayout_free,
+	.ecc = mtk_nfc_ooblayout_ecc,
+};
+
+static void mtk_nfc_set_fdm(struct mtk_nfc_fdm *fdm, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtk_nfc_nand_chip *chip = to_mtk_nand(nand);
+	struct mtk_nfc *nfc = nand_get_controller_data(nand);
+	u32 ecc_bytes;
+
+	ecc_bytes = DIV_ROUND_UP(nand->ecc.strength *
+				 mtk_ecc_get_parity_bits(nfc->ecc), 8);
+
+	fdm->reg_size = chip->spare_per_sector - ecc_bytes;
+	if (fdm->reg_size > NFI_FDM_MAX_SIZE)
+		fdm->reg_size = NFI_FDM_MAX_SIZE;
+
+	/* bad block mark storage */
+	fdm->ecc_size = 1;
+}
+
+static void mtk_nfc_set_bad_mark_ctl(struct mtk_nfc_bad_mark_ctl *bm_ctl,
+				     struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+
+	if (mtd->writesize == 512) {
+		bm_ctl->bm_swap = mtk_nfc_no_bad_mark_swap;
+	} else {
+		bm_ctl->bm_swap = mtk_nfc_bad_mark_swap;
+		bm_ctl->sec = mtd->writesize / mtk_data_len(nand);
+		bm_ctl->pos = mtd->writesize % mtk_data_len(nand);
+	}
+}
+
+static int mtk_nfc_set_spare_per_sector(u32 *sps, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct mtk_nfc *nfc = nand_get_controller_data(nand);
+	const u8 *spare = nfc->caps->spare_size;
+	u32 eccsteps, i, closest_spare = 0;
+
+	eccsteps = mtd->writesize / nand->ecc.size;
+	*sps = mtd->oobsize / eccsteps;
+
+	if (nand->ecc.size == 1024)
+		*sps >>= 1;
+
+	if (*sps < MTK_NFC_MIN_SPARE)
+		return -EINVAL;
+
+	for (i = 0; i < nfc->caps->num_spare_size; i++) {
+		if (*sps >= spare[i] && spare[i] >= spare[closest_spare]) {
+			closest_spare = i;
+			if (*sps == spare[i])
+				break;
+		}
+	}
+
+	*sps = spare[closest_spare];
+
+	if (nand->ecc.size == 1024)
+		*sps <<= 1;
+
+	return 0;
+}
+
+static int mtk_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	const struct nand_ecc_props *requirements =
+		nanddev_get_ecc_requirements(&nand->base);
+	struct mtk_nfc *nfc = nand_get_controller_data(nand);
+	u32 spare;
+	int free, ret;
+
+	/* support only ecc hw mode */
+	if (nand->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST) {
+		dev_err(dev, "ecc.engine_type not supported\n");
+		return -EINVAL;
+	}
+
+	/* if optional dt settings not present */
+	if (!nand->ecc.size || !nand->ecc.strength) {
+		/* use datasheet requirements */
+		nand->ecc.strength = requirements->strength;
+		nand->ecc.size = requirements->step_size;
+
+		/*
+		 * align eccstrength and eccsize
+		 * this controller only supports 512 and 1024 sizes
+		 */
+		if (nand->ecc.size < 1024) {
+			if (mtd->writesize > 512 &&
+			    nfc->caps->max_sector_size > 512) {
+				nand->ecc.size = 1024;
+				nand->ecc.strength <<= 1;
+			} else {
+				nand->ecc.size = 512;
+			}
+		} else {
+			nand->ecc.size = 1024;
+		}
+
+		ret = mtk_nfc_set_spare_per_sector(&spare, mtd);
+		if (ret)
+			return ret;
+
+		/* calculate oob bytes except ecc parity data */
+		free = (nand->ecc.strength * mtk_ecc_get_parity_bits(nfc->ecc)
+			+ 7) >> 3;
+		free = spare - free;
+
+		/*
+		 * enhance ecc strength if oob left is bigger than max FDM size
+		 * or reduce ecc strength if oob size is not enough for ecc
+		 * parity data.
+		 */
+		if (free > NFI_FDM_MAX_SIZE) {
+			spare -= NFI_FDM_MAX_SIZE;
+			nand->ecc.strength = (spare << 3) /
+					     mtk_ecc_get_parity_bits(nfc->ecc);
+		} else if (free < 0) {
+			spare -= NFI_FDM_MIN_SIZE;
+			nand->ecc.strength = (spare << 3) /
+					     mtk_ecc_get_parity_bits(nfc->ecc);
+		}
+	}
+
+	mtk_ecc_adjust_strength(nfc->ecc, &nand->ecc.strength);
+
+	dev_info(dev, "eccsize %d eccstrength %d\n",
+		 nand->ecc.size, nand->ecc.strength);
+
+	return 0;
+}
+
+static int mtk_nfc_attach_chip(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct device *dev = mtd->dev.parent;
+	struct mtk_nfc *nfc = nand_get_controller_data(chip);
+	struct mtk_nfc_nand_chip *mtk_nand = to_mtk_nand(chip);
+	int len;
+	int ret;
+
+	if (chip->options & NAND_BUSWIDTH_16) {
+		dev_err(dev, "16bits buswidth not supported");
+		return -EINVAL;
+	}
+
+	/* store bbt magic in page, cause OOB is not protected */
+	if (chip->bbt_options & NAND_BBT_USE_FLASH)
+		chip->bbt_options |= NAND_BBT_NO_OOB;
+
+	ret = mtk_nfc_ecc_init(dev, mtd);
+	if (ret)
+		return ret;
+
+	ret = mtk_nfc_set_spare_per_sector(&mtk_nand->spare_per_sector, mtd);
+	if (ret)
+		return ret;
+
+	mtk_nfc_set_fdm(&mtk_nand->fdm, mtd);
+	mtk_nfc_set_bad_mark_ctl(&mtk_nand->bad_mark, mtd);
+
+	len = mtd->writesize + mtd->oobsize;
+	nfc->buffer = devm_kzalloc(dev, len, GFP_KERNEL);
+	if (!nfc->buffer)
+		return  -ENOMEM;
+
+	return 0;
+}
+
+static const struct nand_controller_ops mtk_nfc_controller_ops = {
+	.attach_chip = mtk_nfc_attach_chip,
+	.setup_interface = mtk_nfc_setup_interface,
+	.exec_op = mtk_nfc_exec_op,
+};
+
+static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
+				  struct device_node *np)
+{
+	struct mtk_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int nsels;
+	u32 tmp;
+	int ret;
+	int i;
+
+	if (!of_get_property(np, "reg", &nsels))
+		return -ENODEV;
+
+	nsels /= sizeof(u32);
+	if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
+		dev_err(dev, "invalid reg property size %d\n", nsels);
+		return -EINVAL;
+	}
+
+	chip = devm_kzalloc(dev, sizeof(*chip) + nsels * sizeof(u8),
+			    GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->nsels = nsels;
+	for (i = 0; i < nsels; i++) {
+		ret = of_property_read_u32_index(np, "reg", i, &tmp);
+		if (ret) {
+			dev_err(dev, "reg property failure : %d\n", ret);
+			return ret;
+		}
+
+		if (tmp >= MTK_NAND_MAX_NSELS) {
+			dev_err(dev, "invalid CS: %u\n", tmp);
+			return -EINVAL;
+		}
+
+		if (test_and_set_bit(tmp, &nfc->assigned_cs)) {
+			dev_err(dev, "CS %u already assigned\n", tmp);
+			return -EINVAL;
+		}
+
+		chip->sels[i] = tmp;
+	}
+
+	nand = &chip->nand;
+	nand->controller = &nfc->controller;
+
+	nand_set_flash_node(nand, np);
+	nand_set_controller_data(nand, nfc);
+
+	nand->options |= NAND_USES_DMA | NAND_SUBPAGE_READ;
+
+	/* set default mode in case dt entry is missing */
+	nand->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
+
+	nand->ecc.write_subpage = mtk_nfc_write_subpage_hwecc;
+	nand->ecc.write_page_raw = mtk_nfc_write_page_raw;
+	nand->ecc.write_page = mtk_nfc_write_page_hwecc;
+	nand->ecc.write_oob_raw = mtk_nfc_write_oob_std;
+	nand->ecc.write_oob = mtk_nfc_write_oob_std;
+
+	nand->ecc.read_subpage = mtk_nfc_read_subpage_hwecc;
+	nand->ecc.read_page_raw = mtk_nfc_read_page_raw;
+	nand->ecc.read_page = mtk_nfc_read_page_hwecc;
+	nand->ecc.read_oob_raw = mtk_nfc_read_oob_std;
+	nand->ecc.read_oob = mtk_nfc_read_oob_std;
+
+	mtd = nand_to_mtd(nand);
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = dev;
+	mtd->name = MTK_NAME;
+	mtd_set_ooblayout(mtd, &mtk_nfc_ooblayout_ops);
+
+	mtk_nfc_hw_init(nfc);
+
+	ret = nand_scan(nand, nsels);
+	if (ret)
+		return ret;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		dev_err(dev, "mtd parse partition error\n");
+		nand_cleanup(nand);
+		return ret;
+	}
+
+	list_add_tail(&chip->node, &nfc->chips);
+
+	return 0;
+}
+
+static int mtk_nfc_nand_chips_init(struct device *dev, struct mtk_nfc *nfc)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *nand_np;
+	int ret;
+
+	for_each_child_of_node(np, nand_np) {
+		ret = mtk_nfc_nand_chip_init(dev, nfc, nand_np);
+		if (ret) {
+			of_node_put(nand_np);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static const struct mtk_nfc_caps mtk_nfc_caps_mt2701 = {
+	.spare_size = spare_size_mt2701,
+	.num_spare_size = 16,
+	.pageformat_spare_shift = 4,
+	.nfi_clk_div = 1,
+	.max_sector = 16,
+	.max_sector_size = 1024,
+};
+
+static const struct mtk_nfc_caps mtk_nfc_caps_mt2712 = {
+	.spare_size = spare_size_mt2712,
+	.num_spare_size = 19,
+	.pageformat_spare_shift = 16,
+	.nfi_clk_div = 2,
+	.max_sector = 16,
+	.max_sector_size = 1024,
+};
+
+static const struct mtk_nfc_caps mtk_nfc_caps_mt7622 = {
+	.spare_size = spare_size_mt7622,
+	.num_spare_size = 4,
+	.pageformat_spare_shift = 4,
+	.nfi_clk_div = 1,
+	.max_sector = 8,
+	.max_sector_size = 512,
+};
+
+static const struct of_device_id mtk_nfc_id_table[] = {
+	{
+		.compatible = "mediatek,mt2701-nfc",
+		.data = &mtk_nfc_caps_mt2701,
+	}, {
+		.compatible = "mediatek,mt2712-nfc",
+		.data = &mtk_nfc_caps_mt2712,
+	}, {
+		.compatible = "mediatek,mt7622-nfc",
+		.data = &mtk_nfc_caps_mt7622,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mtk_nfc_id_table);
+
+static int mtk_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct mtk_nfc *nfc;
+	struct resource *res;
+	int ret, irq;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	nand_controller_init(&nfc->controller);
+	INIT_LIST_HEAD(&nfc->chips);
+	nfc->controller.ops = &mtk_nfc_controller_ops;
+
+	/* probe defer if not ready */
+	nfc->ecc = of_mtk_ecc_get(np);
+	if (IS_ERR(nfc->ecc))
+		return PTR_ERR(nfc->ecc);
+	else if (!nfc->ecc)
+		return -ENODEV;
+
+	nfc->caps = of_device_get_match_data(dev);
+	nfc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	nfc->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->regs)) {
+		ret = PTR_ERR(nfc->regs);
+		goto release_ecc;
+	}
+
+	nfc->clk.nfi_clk = devm_clk_get(dev, "nfi_clk");
+	if (IS_ERR(nfc->clk.nfi_clk)) {
+		dev_err(dev, "no clk\n");
+		ret = PTR_ERR(nfc->clk.nfi_clk);
+		goto release_ecc;
+	}
+
+	nfc->clk.pad_clk = devm_clk_get(dev, "pad_clk");
+	if (IS_ERR(nfc->clk.pad_clk)) {
+		dev_err(dev, "no pad clk\n");
+		ret = PTR_ERR(nfc->clk.pad_clk);
+		goto release_ecc;
+	}
+
+	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
+	if (ret)
+		goto release_ecc;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = -EINVAL;
+		goto clk_disable;
+	}
+
+	ret = devm_request_irq(dev, irq, mtk_nfc_irq, 0x0, "mtk-nand", nfc);
+	if (ret) {
+		dev_err(dev, "failed to request nfi irq\n");
+		goto clk_disable;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set dma mask\n");
+		goto clk_disable;
+	}
+
+	platform_set_drvdata(pdev, nfc);
+
+	ret = mtk_nfc_nand_chips_init(dev, nfc);
+	if (ret) {
+		dev_err(dev, "failed to init nand chips\n");
+		goto clk_disable;
+	}
+
+	return 0;
+
+clk_disable:
+	mtk_nfc_disable_clk(&nfc->clk);
+
+release_ecc:
+	mtk_ecc_release(nfc->ecc);
+
+	return ret;
+}
+
+static int mtk_nfc_remove(struct platform_device *pdev)
+{
+	struct mtk_nfc *nfc = platform_get_drvdata(pdev);
+	struct mtk_nfc_nand_chip *mtk_chip;
+	struct nand_chip *chip;
+	int ret;
+
+	while (!list_empty(&nfc->chips)) {
+		mtk_chip = list_first_entry(&nfc->chips,
+					    struct mtk_nfc_nand_chip, node);
+		chip = &mtk_chip->nand;
+		ret = mtd_device_unregister(nand_to_mtd(chip));
+		WARN_ON(ret);
+		nand_cleanup(chip);
+		list_del(&mtk_chip->node);
+	}
+
+	mtk_ecc_release(nfc->ecc);
+	mtk_nfc_disable_clk(&nfc->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_nfc_suspend(struct device *dev)
+{
+	struct mtk_nfc *nfc = dev_get_drvdata(dev);
+
+	mtk_nfc_disable_clk(&nfc->clk);
+
+	return 0;
+}
+
+static int mtk_nfc_resume(struct device *dev)
+{
+	struct mtk_nfc *nfc = dev_get_drvdata(dev);
+	struct mtk_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	int ret;
+	u32 i;
+
+	udelay(200);
+
+	ret = mtk_nfc_enable_clk(dev, &nfc->clk);
+	if (ret)
+		return ret;
+
+	/* reset NAND chip if VCC was powered off */
+	list_for_each_entry(chip, &nfc->chips, node) {
+		nand = &chip->nand;
+		for (i = 0; i < chip->nsels; i++)
+			nand_reset(nand, i);
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_nfc_pm_ops, mtk_nfc_suspend, mtk_nfc_resume);
+#endif
+
+static struct platform_driver mtk_nfc_driver = {
+	.probe  = mtk_nfc_probe,
+	.remove = mtk_nfc_remove,
+	.driver = {
+		.name  = MTK_NAME,
+		.of_match_table = mtk_nfc_id_table,
+#ifdef CONFIG_PM_SLEEP
+		.pm = &mtk_nfc_pm_ops,
+#endif
+	},
+};
+
+module_platform_driver(mtk_nfc_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Xiaolei Li <xiaolei.li@mediatek.com>");
+MODULE_DESCRIPTION("MTK Nand Flash Controller Driver");