[v4,2/2] mtd: rawnand: nuvoton: add new driver for the Nuvoton MA35 SoC

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 614257308516..a95d91e61c42 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -448,6 +448,14 @@  config MTD_NAND_RENESAS
 	  Enables support for the NAND controller found on Renesas R-Car
 	  Gen3 and RZ/N1 SoC families.
 
+config MTD_NAND_NUVOTON_MA35
+	tristate "Nuvoton MA35 SoC NAND controller"
+	depends on ARCH_MA35 || COMPILE_TEST
+	depends on OF
+	help
+	  Enables support for the NAND controller found on
+	  the Nuvoton MA35 series SoCs.
+
 comment "Misc"
 
 config MTD_SM_COMMON
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index 25120a4afada..b8e1b3af6942 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -57,6 +57,7 @@  obj-$(CONFIG_MTD_NAND_INTEL_LGM)	+= intel-nand-controller.o
 obj-$(CONFIG_MTD_NAND_ROCKCHIP)		+= rockchip-nand-controller.o
 obj-$(CONFIG_MTD_NAND_PL35X)		+= pl35x-nand-controller.o
 obj-$(CONFIG_MTD_NAND_RENESAS)		+= renesas-nand-controller.o
+obj-$(CONFIG_MTD_NAND_NUVOTON_MA35)	+= nuvoton_ma35d1_nand.o
 
 nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
 nand-objs += nand_onfi.o
diff --git a/drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c b/drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c
new file mode 100644
index 000000000000..30cbcb999f1a
--- /dev/null
+++ b/drivers/mtd/nand/raw/nuvoton_ma35d1_nand.c
@@ -0,0 +1,935 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+
+/* NFI Registers */
+#define MA35_NFI_REG_DMACTL		0x400
+#define   DMA_EN				BIT(0)
+#define   DMA_RST				BIT(1)
+#define   DMA_BUSY				BIT(9)
+
+#define MA35_NFI_REG_DMASA		0x408
+#define MA35_NFI_REG_GCTL		0x800
+#define   NAND_EN				BIT(3)
+
+#define MA35_NFI_REG_NANDCTL		0x8A0
+#define   SWRST				BIT(0)
+#define   DMA_R_EN				BIT(1)
+#define   DMA_W_EN				BIT(2)
+#define   ECC_CHK				BIT(7)
+#define   PROT3BEN				BIT(8)
+#define   PSIZE_2K				(1 << 16)
+#define   PSIZE_4K				(2 << 16)
+#define   PSIZE_8K				(3 << 16)
+#define   PSIZE_MASK				(3 << 16)
+#define   BCH_T24				BIT(18)
+#define   BCH_T8				BIT(20)
+#define   BCH_T12				BIT(21)
+#define   BCH_NONE				(0x0)
+#define   BCH_MASK				(0x1f << 18)
+#define   ECC_EN				BIT(23)
+#define   DISABLE_CS0				BIT(25)
+
+#define MA35_NFI_REG_NANDINTEN	0x8A8
+#define MA35_NFI_REG_NANDINTSTS	0x8AC
+#define   INT_DMA				BIT(0)
+#define   INT_ECC				BIT(2)
+#define   INT_RB0				BIT(10)
+#define   INT_RB0_STS				BIT(18)
+
+#define MA35_NFI_REG_NANDCMD		0x8B0
+#define MA35_NFI_REG_NANDADDR		0x8B4
+#define   ENDADDR				BIT(31)
+
+#define MA35_NFI_REG_NANDDATA		0x8B8
+#define MA35_NFI_REG_NANDRACTL	0x8BC
+#define MA35_NFI_REG_NANDECTL		0x8C0
+#define   ENABLE_WP				0x0
+#define   DISABLE_WP				BIT(0)
+
+#define MA35_NFI_REG_NANDECCES0	0x8D0
+#define   ECC_STATUS_MASK			0x3
+#define   ECC_ERR_CNT_MASK			0x1f
+
+#define MA35_NFI_REG_NANDECCEA0	0x900
+#define MA35_NFI_REG_NANDECCED0	0x960
+#define MA35_NFI_REG_NANDRA0		0xA00
+
+#define SKIP_SPARE_BYTES	4
+
+
+/* Define for the BCH hardware ECC engine */
+/* define the total padding bytes for 512/1024 data segment */
+#define MA35_BCH_PADDING_512	32
+#define MA35_BCH_PADDING_1024	64
+/* define the BCH parity code length for 512 bytes data pattern */
+#define MA35_PARITY_BCH8	15
+#define MA35_PARITY_BCH12	23
+/* define the BCH parity code length for 1024 bytes data pattern */
+#define MA35_PARITY_BCH24	45
+
+
+struct ma35_nand_info {
+	struct nand_controller controller;
+	struct nand_chip chip;
+	struct device *dev;
+	void __iomem *regs;
+	int irq;
+	struct clk *clk;
+	struct completion complete;
+
+	u32 bch;
+	u8 *dma_buf;
+	u8 *ecc_buf;
+	spinlock_t dma_lock;
+	dma_addr_t dma_addr;
+};
+
+static int ma35_ooblayout_ecc(struct mtd_info *mtd, int section,
+			      struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (section)
+		return -ERANGE;
+
+	oobregion->length = chip->ecc.total;
+	oobregion->offset = mtd->oobsize - oobregion->length;
+
+	return 0;
+}
+
+static int ma35_ooblayout_free(struct mtd_info *mtd, int section,
+			       struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (section)
+		return -ERANGE;
+
+	oobregion->length = mtd->oobsize - chip->ecc.total - 2;
+	oobregion->offset = 2;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops ma35_ooblayout_ops = {
+	.free = ma35_ooblayout_free,
+	.ecc = ma35_ooblayout_ecc,
+};
+
+static inline void ma35_clear_spare(struct nand_chip *chip, int size)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	int i;
+
+	for (i = 0; i < size/4; i++)
+		writel(0xff, nand->regs + MA35_NFI_REG_NANDRA0);
+}
+
+static inline void read_remaining_bytes(struct ma35_nand_info *nand, u32 *buf,
+						u32 offset, int size)
+{
+	u32 value = readl(nand->regs + MA35_NFI_REG_NANDRA0 + offset);
+	u8 *ptr = (u8 *)buf;
+	int i;
+
+	for (i = 0; i < size; i++)
+		ptr[i] = (value >> (i * 8)) & 0xff;
+}
+
+
+static inline void ma35_read_spare(struct nand_chip *chip, int size, u32 *buf, u32 offset)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	int i, j;
+
+	if ((offset % 4) == 0) {
+		for (i = 0, j = 0; i < size / 4; i++, j += 4)
+			*buf++ = readl(nand->regs + MA35_NFI_REG_NANDRA0 + offset + j);
+
+		read_remaining_bytes(nand, buf, offset + j, size % 4);
+	} else {
+		read_remaining_bytes(nand, buf, offset, 4 - (offset % 4));
+		offset += 4;
+		size -= (4 - (offset % 4));
+
+		for (i = 0, j = 0; i < size / 4; i++, j += 4)
+			*buf++ = readl(nand->regs + MA35_NFI_REG_NANDRA0 + offset + j);
+
+		read_remaining_bytes(nand, buf, offset + j, size % 4);
+	}
+}
+
+static inline void ma35_write_spare(struct nand_chip *chip, int size, u32 *buf)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	u32 value;
+	int i, j;
+	u8 *ptr;
+
+	for (i = 0, j = 0; i < size / 4; i++, j += 4)
+		writel(*buf++, nand->regs + MA35_NFI_REG_NANDRA0 + j);
+
+	ptr = (u8 *)buf;
+	switch (size % 4) {
+	case 1:
+		writel(*ptr, nand->regs + MA35_NFI_REG_NANDRA0 + j);
+		break;
+	case 2:
+		value = *ptr | (*(ptr+1) << 8);
+		writel(value, nand->regs + MA35_NFI_REG_NANDRA0 + j);
+		break;
+	case 3:
+		value = *ptr | (*(ptr+1) << 8) | (*(ptr+2) << 16);
+		writel(value, nand->regs + MA35_NFI_REG_NANDRA0 + j);
+		break;
+	default:
+		break;
+	}
+}
+
+static inline void ma35_nand_target_enable(struct ma35_nand_info *nand)
+{
+	writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) & (~DISABLE_CS0),
+		nand->regs+MA35_NFI_REG_NANDCTL);
+}
+
+static inline void ma35_nand_target_disable(struct ma35_nand_info *nand)
+{
+	writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) | DISABLE_CS0,
+		nand->regs + MA35_NFI_REG_NANDCTL);
+}
+
+/*
+ * Initialize hardware ECC
+ */
+static void ma35_nand_hwecc_init(struct ma35_nand_info *nand)
+{
+	struct mtd_info *mtd = nand_to_mtd(&nand->chip);
+	u32 reg;
+
+	/* resets the internal state machine and counters */
+	reg = readl(nand->regs + MA35_NFI_REG_NANDCTL);
+	reg |= SWRST;
+	writel(reg, nand->regs + MA35_NFI_REG_NANDCTL);
+	while (readl(nand->regs + MA35_NFI_REG_NANDCTL) & SWRST)
+		;
+
+	/* Redundant area size */
+	writel(mtd->oobsize, nand->regs + MA35_NFI_REG_NANDRACTL);
+
+	/* Protect redundant 3 bytes */
+	reg = readl(nand->regs + MA35_NFI_REG_NANDCTL);
+	reg |= (PROT3BEN | ECC_CHK);
+	writel(reg, nand->regs + MA35_NFI_REG_NANDCTL);
+
+	if (nand->bch == BCH_NONE) {
+		/* Disable H/W ECC, ECC parity check enable bit during read page */
+		writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) & (~ECC_EN),
+			nand->regs + MA35_NFI_REG_NANDCTL);
+	} else {
+		/* Set BCH algorithm */
+		writel((readl(nand->regs + MA35_NFI_REG_NANDCTL) & (~BCH_MASK)) |
+			nand->bch, nand->regs + MA35_NFI_REG_NANDCTL);
+
+		/* Enable H/W ECC, ECC parity check enable bit during read page */
+		writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) | ECC_EN,
+			nand->regs + MA35_NFI_REG_NANDCTL);
+	}
+	spin_lock_init(&nand->dma_lock);
+}
+
+
+/* Correct data by BCH alrogithm */
+static void ma35_nfi_correct(struct ma35_nand_info *nand, u8 index,
+				 u8 err_cnt, u8 *addr)
+{
+	u32 temp_data[24], temp_addr[24];
+	u32 padding_len, parity_len;
+	u32 value, offset, remain;
+	u32 err_data[6];
+	u8  i, j;
+
+	/* configurations */
+	switch (nand->bch) {
+	case BCH_T24:
+		parity_len = MA35_PARITY_BCH24;
+		padding_len = MA35_BCH_PADDING_1024;
+		break;
+	case BCH_T12:
+		parity_len = MA35_PARITY_BCH12;
+		padding_len = MA35_BCH_PADDING_512;
+		break;
+	case BCH_T8:
+		parity_len = MA35_PARITY_BCH8;
+		padding_len = MA35_BCH_PADDING_512;
+		break;
+	default:
+		dev_warn(nand->dev, "NAND ERROR: invalid SMCR_BCH_TSEL = 0x%08X\n",
+			(u32)(readl(nand->regs + MA35_NFI_REG_NANDCTL) & BCH_MASK));
+		return;
+	}
+
+	/* got valid BCH_ECC_DATAx and parse them to temp_data[]
+	 * got the valid register number of BCH_ECC_DATAx since
+	 * one register include 4 error bytes
+	 */
+	j = (err_cnt + 3) / 4;
+	j = (j > 6) ? 6 : j;
+	for (i = 0; i < j; i++)
+		err_data[i] = readl(nand->regs + MA35_NFI_REG_NANDECCED0 + i * 4);
+
+	for (i = 0; i < j; i++) {
+		temp_data[i*4+0] = err_data[i] & 0xff;
+		temp_data[i*4+1] = (err_data[i] >> 8) & 0xff;
+		temp_data[i*4+2] = (err_data[i] >> 16) & 0xff;
+		temp_data[i*4+3] = (err_data[i] >> 24) & 0xff;
+	}
+
+	/* got valid REG_BCH_ECC_ADDRx and parse them to temp_addr[]
+	 * got the valid register number of REG_BCH_ECC_ADDRx since
+	 * one register include 2 error addresses
+	 */
+	j = (err_cnt + 1) / 2;
+	j = (j > 12) ? 12 : j;
+	for (i = 0; i < j; i++) {
+		temp_addr[i*2+0] = readl(nand->regs + MA35_NFI_REG_NANDECCEA0 + i * 4)
+					& 0x07ff;
+		temp_addr[i*2+1] = (readl(nand->regs + MA35_NFI_REG_NANDECCEA0 + i * 4) >> 16)
+					& 0x07ff;
+	}
+
+	/* pointer to begin address of field that with data error */
+	addr += index * nand->chip.ecc.steps;
+
+	/* correct each error bytes */
+	for (i = 0; i < err_cnt; i++) {
+		u32 corrected_index = temp_addr[i];
+
+		/* for wrong data in field */
+		if (corrected_index < nand->chip.ecc.steps)
+			*(addr + corrected_index) ^= temp_data[i];
+
+		/* for wrong first-3-bytes in redundancy area */
+		else if (corrected_index < (nand->chip.ecc.steps + 3)) {
+			corrected_index -= nand->chip.ecc.steps;
+			temp_addr[i] += (parity_len * index);	/* field offset */
+
+			value = readl(nand->regs + MA35_NFI_REG_NANDRA0);
+			value ^= temp_data[i] << (8 * corrected_index);
+			writel(value, nand->regs + MA35_NFI_REG_NANDRA0);
+		}
+		/* for wrong parity code in redundancy area
+		 * BCH_ERR_ADDRx = [data in field] + [3 bytes] + [xx] + [parity code]
+		 *                                   |<--     padding bytes      -->|
+		 * The BCH_ERR_ADDRx for last parity code always = field size + padding size.
+		 * So, the first parity code = field size + padding size - parity code length.
+		 * For example, for BCH T12, the first parity code = 512 + 32 - 23 = 521.
+		 * That is, error byte address offset within field is
+		 */
+		else {
+			corrected_index -= (nand->chip.ecc.steps + padding_len - parity_len);
+
+			/* final address = first parity code of first field +
+			 *                 offset of fields +
+			 *                 offset within field
+			 */
+			offset = (readl(nand->regs+MA35_NFI_REG_NANDRACTL) & 0x1ff) -
+				(parity_len * nand->chip.ecc.steps) +
+				(parity_len * index) + corrected_index;
+
+			remain = offset % 4;
+			value = readl(nand->regs + MA35_NFI_REG_NANDRA0 + offset - remain);
+			value ^= temp_data[i] << (8 * remain);
+			writel(value, nand->regs + MA35_NFI_REG_NANDRA0 + offset - remain);
+		}
+	}
+}
+
+static int ma35_nfi_ecc_check(struct nand_chip *chip, unsigned long addr)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int status, i, j, nchunks = 0;
+	int report_err = 0;
+	int err_cnt = 0;
+
+	nchunks = mtd->writesize / chip->ecc.steps;
+	if (nchunks < 4)
+		nchunks = 1;
+	else
+		nchunks /= 4;
+
+	for (j = 0; j < nchunks; j++) {
+		status = readl(nand->regs + MA35_NFI_REG_NANDECCES0 + j*4);
+		if (!status)
+			continue;
+
+		for (i = 0; i < 4; i++) {
+			if (!(status & ECC_STATUS_MASK)) {
+				/* No error */
+				status >>= 8;
+				continue;
+
+			} else if ((status & ECC_STATUS_MASK) == 0x01) {
+				/* Correctable error */
+				err_cnt = (status >> 2) & ECC_ERR_CNT_MASK;
+				dev_warn(nand->dev, "nchunks (%d, %d) have %d error!\n",
+					j, i, err_cnt);
+				ma35_nfi_correct(nand, j*4+i, err_cnt, (u8 *)addr);
+				report_err += err_cnt;
+
+			} else {
+				/* uncorrectable error */
+				dev_warn(nand->dev, "uncorrectable error! 0x%4x\n", status);
+				return -1;
+			}
+			status >>= 8;
+		}
+	}
+	return report_err;
+}
+
+
+/*
+ * Initialize DMA
+ */
+static void ma35_nand_dmac_init(struct ma35_nand_info *nand)
+{
+	/* DMAC reset and enable */
+	writel(DMA_RST | DMA_EN, nand->regs + MA35_NFI_REG_DMACTL);
+	writel(DMA_EN, nand->regs + MA35_NFI_REG_DMACTL);
+
+	/* Clear DMA finished flag */
+	writel(INT_DMA | INT_ECC, nand->regs + MA35_NFI_REG_NANDINTSTS);
+
+	init_completion(&nand->complete);
+}
+
+
+/*
+ * configure and start dma transfer
+ */
+static int ma35_nand_do_write(struct nand_chip *chip, const u8 *addr, u32 len)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	dma_addr_t dma_addr;
+	int ret = 0, i;
+	u32 val, reg;
+
+	ma35_nand_target_enable(nand);
+
+	if (len != mtd->writesize) {
+		for (i = 0; i < len; i++)
+			writel(addr[i], nand->regs + MA35_NFI_REG_NANDDATA);
+		ma35_nand_target_disable(nand);
+		return ret;
+	}
+
+	/* Check the DMA status before enabling the DMA */
+	ret = readl_poll_timeout(nand->regs + MA35_NFI_REG_DMACTL, val,
+				 !(val & DMA_BUSY), 50, HZ/2);
+	if (ret)
+		dev_warn(nand->dev, "dma busy\n");
+
+	/* Reinitial dmac */
+	ma35_nand_dmac_init(nand);
+
+	writel(mtd->oobsize, nand->regs + MA35_NFI_REG_NANDRACTL);
+
+	/* setup and start DMA using dma_addr */
+	writel(INT_DMA, nand->regs + MA35_NFI_REG_NANDINTEN);
+	/* To mark this page as dirty. */
+	reg = readl(nand->regs + MA35_NFI_REG_NANDRA0);
+	if (reg & 0xffff0000)
+		writel(reg & 0xffff, nand->regs + MA35_NFI_REG_NANDRA0);
+
+	/* Fill dma_addr */
+	dma_addr = dma_map_single(nand->dev, (void *)addr, len, DMA_TO_DEVICE);
+	dma_sync_single_for_device(nand->dev, dma_addr, len, DMA_TO_DEVICE);
+	ret = dma_mapping_error(nand->dev, dma_addr);
+	if (ret) {
+		dev_err(nand->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	writel((unsigned long)dma_addr, nand->regs + MA35_NFI_REG_DMASA);
+	writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) | DMA_W_EN,
+		nand->regs + MA35_NFI_REG_NANDCTL);
+	ret = wait_for_completion_timeout(&nand->complete, msecs_to_jiffies(1000));
+	if (!ret) {
+		dev_err(nand->dev, "write timeout\n");
+		ret = -ETIMEDOUT;
+	}
+
+	dma_unmap_single(nand->dev, dma_addr, len, DMA_TO_DEVICE);
+
+	ma35_nand_target_disable(nand);
+
+	return ret;
+}
+
+static int ma35_nand_do_read(struct nand_chip *chip, const u8 *addr, u32 len)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u8 *ptr = (u8 *)addr;
+	dma_addr_t dma_addr;
+	int ret = 0, i;
+	u32 val;
+
+	ma35_nand_target_enable(nand);
+
+	if (len != mtd->writesize) {
+		for (i = 0; i < len; i++)
+			*(ptr+i) = (u8)readl(nand->regs + MA35_NFI_REG_NANDDATA);
+		ma35_nand_target_disable(nand);
+		return ret;
+	}
+
+	/* Check the DMA status before enabling the DMA */
+	ret = readl_poll_timeout(nand->regs + MA35_NFI_REG_DMACTL, val,
+				 !(val & DMA_BUSY), 50, HZ/2);
+	if (ret)
+		dev_warn(nand->dev, "dma busy\n");
+
+	/* Reinitial dmac */
+	ma35_nand_dmac_init(nand);
+
+	writel(mtd->oobsize, nand->regs + MA35_NFI_REG_NANDRACTL);
+
+	/* setup and start DMA using dma_addr */
+	dma_addr = dma_map_single(nand->dev, (void *)addr, len, DMA_FROM_DEVICE);
+	ret = dma_mapping_error(nand->dev, dma_addr);
+	if (ret) {
+		dev_err(nand->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+	nand->dma_buf = (u8 *)addr;
+	nand->dma_addr = dma_addr;
+
+	writel((unsigned long)dma_addr, nand->regs + MA35_NFI_REG_DMASA);
+	writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) | DMA_R_EN,
+		nand->regs + MA35_NFI_REG_NANDCTL);
+	ret = wait_for_completion_timeout(&nand->complete, msecs_to_jiffies(1000));
+	if (!ret) {
+		dev_err(nand->dev, "read timeout\n");
+		ret = -ETIMEDOUT;
+	}
+
+	dma_sync_single_for_cpu(nand->dev, dma_addr, len, DMA_FROM_DEVICE);
+	dma_unmap_single(nand->dev, dma_addr, len, DMA_FROM_DEVICE);
+
+	ma35_nand_target_disable(nand);
+
+	return ret;
+}
+
+
+static int ma35_nand_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
+				      int oob_required, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u8 *ecc_calc = chip->ecc.calc_buf;
+
+	ma35_clear_spare(chip, mtd->oobsize);
+	ma35_write_spare(chip, mtd->oobsize - chip->ecc.total, (u32 *)chip->oob_poi);
+
+	nand_prog_page_begin_op(chip, page, 0, buf, mtd->writesize);
+	nand_prog_page_end_op(chip);
+
+	/* Copy parity code in NANDRA to calc */
+	ma35_read_spare(chip, chip->ecc.total, (u32 *)ecc_calc,
+			mtd->oobsize - chip->ecc.total);
+
+	/* Copy parity code in calc to oob_poi */
+	memcpy((void *)(chip->oob_poi + (mtd->oobsize - chip->ecc.total)),
+		(void *)ecc_calc, chip->ecc.total);
+
+	return 0;
+}
+
+static int ma35_nand_read_page_hwecc(struct nand_chip *chip, u8 *buf,
+					int oob_required, int page)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u32 reg;
+
+	/* read the OOB area  */
+	nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
+
+	/* copy OOB data to NANDRA for page read */
+	ma35_write_spare(chip, mtd->oobsize, (u32 *)chip->oob_poi);
+
+	reg = readl(nand->regs + MA35_NFI_REG_NANDRA0);
+	if (reg & 0xffff0000)
+		memset((void *)buf, 0xff, mtd->writesize);
+	else {
+		/* read data from nand */
+		nand_read_page_op(chip, page, 0, buf, mtd->writesize);
+
+		/* restore OOB data from SMRA */
+		ma35_read_spare(chip, mtd->oobsize, (u32 *)chip->oob_poi, 0);
+	}
+
+	return 0;
+}
+
+
+static int ma35_nand_read_oob_hwecc(struct nand_chip *chip, int page)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	u32 reg;
+
+	nand_read_oob_op(chip, page, 0, chip->oob_poi, mtd->oobsize);
+
+	/* copy OOB data to NANDRA for page read */
+	ma35_write_spare(chip, mtd->oobsize, (u32 *)chip->oob_poi);
+
+	reg = readl(nand->regs + MA35_NFI_REG_NANDRA0);
+	if (reg & 0xffff0000)
+		memset((void *)chip->oob_poi, 0xff, mtd->oobsize);
+
+	return 0;
+}
+
+static irqreturn_t ma35_nand_irq(int irq, void *id)
+{
+	struct ma35_nand_info *nand = (struct ma35_nand_info *)id;
+	struct mtd_info *mtd = nand_to_mtd(&nand->chip);
+	int stat = 0;
+	u32 isr;
+
+	spin_lock(&nand->dma_lock);
+
+	isr = readl(nand->regs + MA35_NFI_REG_NANDINTSTS);
+	if (isr & INT_ECC) {
+		dma_sync_single_for_cpu(nand->dev, nand->dma_addr, mtd->writesize,
+					DMA_FROM_DEVICE);
+		stat = ma35_nfi_ecc_check(&nand->chip, (unsigned long)nand->dma_buf);
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+			writel(DMA_RST | DMA_EN, nand->regs + MA35_NFI_REG_DMACTL);
+			writel(readl(nand->regs + MA35_NFI_REG_NANDCTL) | SWRST,
+				nand->regs + MA35_NFI_REG_NANDCTL);
+		} else if (stat > 0) {
+			mtd->ecc_stats.corrected += stat;   /* Add corrected bit count */
+		}
+		writel(INT_ECC, nand->regs + MA35_NFI_REG_NANDINTSTS);
+	}
+	if (isr & INT_DMA) {
+		writel(INT_DMA, nand->regs + MA35_NFI_REG_NANDINTSTS);
+		complete(&nand->complete);
+	}
+	spin_unlock(&nand->dma_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int ma35_nand_attach_chip(struct nand_chip *chip)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	unsigned int reg;
+
+	if (chip->options & NAND_BUSWIDTH_16) {
+		dev_err(nand->dev, "16 bits bus width not supported");
+		return -EINVAL;
+	}
+
+	/* support only ecc hw mode */
+	if (chip->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST) {
+		dev_err(nand->dev, "ecc.engine_type not supported\n");
+		return -EINVAL;
+	}
+
+	nand->ecc_buf = devm_kzalloc(nand->dev, mtd->writesize + mtd->oobsize, GFP_KERNEL);
+	if (!nand->ecc_buf)
+		return  -ENOMEM;
+	chip->ecc.calc_buf = nand->ecc_buf;
+
+	/* Set PSize */
+	reg = readl(nand->regs + MA35_NFI_REG_NANDCTL) & (~PSIZE_MASK);
+	if (mtd->writesize == 2048)
+		writel(reg | PSIZE_2K, nand->regs + MA35_NFI_REG_NANDCTL);
+	else if (mtd->writesize == 4096)
+		writel(reg | PSIZE_4K, nand->regs + MA35_NFI_REG_NANDCTL);
+	else if (mtd->writesize == 8192)
+		writel(reg | PSIZE_8K, nand->regs + MA35_NFI_REG_NANDCTL);
+
+	chip->ecc.steps = mtd->writesize / chip->ecc.size;
+	if (chip->ecc.strength == 0) {
+		nand->bch = BCH_NONE; /* No ECC */
+		chip->ecc.total = 0;
+
+	} else if (chip->ecc.strength <= 8) {
+		nand->bch = BCH_T8; /* T8 */
+		chip->ecc.total = chip->ecc.steps * MA35_PARITY_BCH8;
+
+	} else if (chip->ecc.strength <= 12) {
+		nand->bch = BCH_T12; /* T12 */
+		chip->ecc.total = chip->ecc.steps * MA35_PARITY_BCH12;
+
+	} else if (chip->ecc.strength <= 24) {
+		nand->bch = BCH_T24; /* T24 */
+		chip->ecc.total = chip->ecc.steps * MA35_PARITY_BCH24;
+
+	} else {
+		dev_warn(nand->dev, "NAND Controller is not support this flash. (%d, %d)\n",
+			mtd->writesize, mtd->oobsize);
+	}
+
+	chip->ecc.bytes = chip->ecc.total / chip->ecc.steps;
+	mtd_set_ooblayout(mtd, &ma35_ooblayout_ops);
+
+	/* add mtd-id. The string should same as uboot definition */
+	mtd->name = "nand0";
+
+	ma35_nand_hwecc_init(nand);
+
+	writel(DISABLE_WP, nand->regs + MA35_NFI_REG_NANDECTL);
+
+	return 0;
+}
+
+
+
+static int ma35_nfc_exec_instr(struct nand_chip *chip,
+			      const struct nand_op_instr *instr)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	unsigned int i;
+	u32 status;
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		writel(instr->ctx.cmd.opcode, nand->regs + MA35_NFI_REG_NANDCMD);
+		return 0;
+
+	case NAND_OP_ADDR_INSTR:
+		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
+			if (i == (instr->ctx.addr.naddrs - 1))
+				writel(instr->ctx.addr.addrs[i] | ENDADDR,
+					nand->regs + MA35_NFI_REG_NANDADDR);
+			else
+				writel(instr->ctx.addr.addrs[i],
+					nand->regs + MA35_NFI_REG_NANDADDR);
+		}
+		return 0;
+
+	case NAND_OP_DATA_IN_INSTR:
+		ma35_nand_do_read(chip, instr->ctx.data.buf.in, instr->ctx.data.len);
+		return 0;
+
+	case NAND_OP_DATA_OUT_INSTR:
+		ma35_nand_do_write(chip, instr->ctx.data.buf.out, instr->ctx.data.len);
+		return 0;
+
+	case NAND_OP_WAITRDY_INSTR:
+		return readl_poll_timeout(nand->regs + MA35_NFI_REG_NANDINTSTS, status,
+					  status & INT_RB0, 20,
+					  instr->ctx.waitrdy.timeout_ms * 1000);
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+
+static int ma35_nfc_exec_op(struct nand_chip *chip,
+			  const struct nand_operation *op,
+			  bool check_only)
+{
+	struct ma35_nand_info *nand = nand_get_controller_data(chip);
+	u32 i, reg;
+	int ret = 0;
+
+	if (check_only)
+		return 0;
+
+	ma35_nand_target_enable(nand);
+	reg = readl(nand->regs + MA35_NFI_REG_NANDINTSTS);
+	reg |= INT_RB0;
+	writel(reg, nand->regs + MA35_NFI_REG_NANDINTSTS);
+
+	for (i = 0; i < op->ninstrs; i++) {
+		ret = ma35_nfc_exec_instr(chip, &op->instrs[i]);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+
+static const struct nand_controller_ops ma35_nfc_ops = {
+	.attach_chip = ma35_nand_attach_chip,
+	.exec_op = ma35_nfc_exec_op,
+};
+
+static int ma35_nand_probe(struct platform_device *pdev)
+{
+	struct ma35_nand_info *nand;
+	struct nand_chip *chip;
+	struct mtd_info *mtd;
+	int ret = 0;
+
+	nand = devm_kzalloc(&pdev->dev, sizeof(*nand), GFP_KERNEL);
+	if (!nand)
+		return -ENOMEM;
+
+	nand_controller_init(&nand->controller);
+	nand->controller.ops = &ma35_nfc_ops;
+
+	nand->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(nand->regs))
+		return PTR_ERR(nand->regs);
+
+	nand->dev = &pdev->dev;
+	chip = &nand->chip;
+	nand_set_controller_data(chip, nand);
+	nand_set_flash_node(chip, pdev->dev.of_node);
+
+	nand->clk = devm_clk_get_enabled(&pdev->dev, "nand_gate");
+	if (IS_ERR(nand->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(nand->clk),
+				     "failed to find nand clock\n");
+
+	nand->irq = platform_get_irq(pdev, 0);
+	if (nand->irq < 0)
+		return dev_err_probe(&pdev->dev, nand->irq,
+				     "failed to get platform irq\n");
+
+	ret = devm_request_irq(&pdev->dev, nand->irq, ma35_nand_irq,
+				  IRQF_TRIGGER_HIGH, "ma35d1-nand", nand);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to request NAND irq\n");
+		clk_disable_unprepare(nand->clk);
+		return -ENXIO;
+	}
+
+	nand->chip.controller = &nand->controller;
+	platform_set_drvdata(pdev, nand);
+
+	chip->options |= NAND_NO_SUBPAGE_WRITE | NAND_USES_DMA;
+
+	/* set default mode in case dt entry is missing */
+	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_ON_HOST;
+
+	chip->ecc.write_page = ma35_nand_write_page_hwecc;
+	chip->ecc.read_page  = ma35_nand_read_page_hwecc;
+	chip->ecc.read_oob   = ma35_nand_read_oob_hwecc;
+
+	mtd = nand_to_mtd(chip);
+	mtd->priv = chip;
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = &pdev->dev;
+
+	writel(NAND_EN, nand->regs + MA35_NFI_REG_GCTL);
+
+	ret = nand_scan(chip, 1);
+	if (ret)
+		return ret;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		nand_cleanup(chip);
+		devm_kfree(&pdev->dev, nand);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void ma35_nand_remove(struct platform_device *pdev)
+{
+	struct ma35_nand_info *nand = platform_get_drvdata(pdev);
+	int ret;
+
+	devm_free_irq(&pdev->dev, nand->irq, nand);
+	ret = mtd_device_unregister(nand_to_mtd(&nand->chip));
+	WARN_ON(ret);
+	nand_cleanup(&nand->chip);
+	clk_disable_unprepare(nand->clk);
+}
+
+/* PM Support */
+#ifdef CONFIG_PM
+static int ma35_nand_suspend(struct platform_device *pdev, pm_message_t pm)
+{
+	struct ma35_nand_info *nand = platform_get_drvdata(pdev);
+	int ret = 0;
+	u32 val;
+
+	/* wait DMAC to ready */
+	ret = readl_poll_timeout(nand->regs + MA35_NFI_REG_DMACTL, val,
+				 !(val & DMA_BUSY), 50, HZ/2);
+	if (ret)
+		dev_warn(&pdev->dev, "dma busy\n");
+
+	clk_disable(nand->clk);
+
+	return ret;
+}
+
+static int ma35_nand_resume(struct platform_device *pdev)
+{
+	struct ma35_nand_info *nand = platform_get_drvdata(pdev);
+
+	clk_enable(nand->clk);
+	ma35_nand_hwecc_init(nand);
+	ma35_nand_dmac_init(nand);
+
+	return 0;
+}
+
+#else
+#define ma35_nand_suspend NULL
+#define ma35_nand_resume NULL
+#endif
+
+static const struct of_device_id ma35_nfi_of_match[] = {
+	{ .compatible = "nuvoton,ma35d1-nand" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ma35_nfi_of_match);
+
+static struct platform_driver ma35_nand_driver = {
+	.driver = {
+		.name = "ma35d1-nand",
+		.of_match_table = ma35_nfi_of_match,
+	},
+	.probe = ma35_nand_probe,
+	.remove = ma35_nand_remove,
+	.suspend = ma35_nand_suspend,
+	.resume = ma35_nand_resume,
+};
+
+module_platform_driver(ma35_nand_driver);
+
+MODULE_DESCRIPTION("Nuvoton ma35 NAND driver");
+MODULE_AUTHOR("Hui-Ping Chen <hpchen0nvt@gmail.com>");
+MODULE_LICENSE("GPL");