diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 3a1d8f1170de..6ee514fd0920 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -433,6 +433,16 @@ config SPI_MT7621
 	help
 	  This selects a driver for the MediaTek MT7621 SPI Controller.
 
+config SPI_NPCM_FIU
+	tristate "Nuvoton NPCM FLASH Interface Unit"
+	depends on ARCH_NPCM || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	help
+	  This enables support for the Flash Interface Unit SPI controller
+	  in master mode.
+	  This driver does not support generic SPI. The implementation only
+	  supports spi-mem interface.
+
 config SPI_NPCM_PSPI
 	tristate "Nuvoton NPCM PSPI Controller"
 	depends on ARCH_NPCM || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 63dcab552bcb..adbebee93a75 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -63,6 +63,7 @@ obj-$(CONFIG_SPI_MT65XX)                += spi-mt65xx.o
 obj-$(CONFIG_SPI_MT7621)		+= spi-mt7621.o
 obj-$(CONFIG_SPI_MXIC)			+= spi-mxic.o
 obj-$(CONFIG_SPI_MXS)			+= spi-mxs.o
+obj-$(CONFIG_SPI_NPCM_FIU)		+= spi-npcm-fiu.o
 obj-$(CONFIG_SPI_NPCM_PSPI)		+= spi-npcm-pspi.o
 obj-$(CONFIG_SPI_NUC900)		+= spi-nuc900.o
 obj-$(CONFIG_SPI_NXP_FLEXSPI)		+= spi-nxp-fspi.o
diff --git a/drivers/spi/spi-npcm-fiu.c b/drivers/spi/spi-npcm-fiu.c
new file mode 100644
index 000000000000..c175c6571237
--- /dev/null
+++ b/drivers/spi/spi-npcm-fiu.c
@@ -0,0 +1,760 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Nuvoton Technology corporation.
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/vmalloc.h>
+#include <linux/regmap.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi-mem.h>
+#include <linux/mfd/syscon.h>
+
+/* NPCM7xx GCR module */
+#define NPCM7XX_INTCR3_OFFSET		0x9C
+#define NPCM7XX_INTCR3_FIU_FIX		BIT(6)
+
+/* Flash Interface Unit (FIU) Registers */
+#define NPCM_FIU_DRD_CFG		0x00
+#define NPCM_FIU_DWR_CFG		0x04
+#define NPCM_FIU_UMA_CFG		0x08
+#define NPCM_FIU_UMA_CTS		0x0C
+#define NPCM_FIU_UMA_CMD		0x10
+#define NPCM_FIU_UMA_ADDR		0x14
+#define NPCM_FIU_PRT_CFG		0x18
+#define NPCM_FIU_UMA_DW0		0x20
+#define NPCM_FIU_UMA_DW1		0x24
+#define NPCM_FIU_UMA_DW2		0x28
+#define NPCM_FIU_UMA_DW3		0x2C
+#define NPCM_FIU_UMA_DR0		0x30
+#define NPCM_FIU_UMA_DR1		0x34
+#define NPCM_FIU_UMA_DR2		0x38
+#define NPCM_FIU_UMA_DR3		0x3C
+#define NPCM_FIU_MAX_REG_LIMIT		0x80
+
+/* FIU Direct Read Configuration Register */
+#define NPCM_FIU_DRD_CFG_LCK		BIT(31)
+#define NPCM_FIU_DRD_CFG_R_BURST	GENMASK(25, 24)
+#define NPCM_FIU_DRD_CFG_ADDSIZ		GENMASK(17, 16)
+#define NPCM_FIU_DRD_CFG_DBW		GENMASK(13, 12)
+#define NPCM_FIU_DRD_CFG_ACCTYPE	GENMASK(9, 8)
+#define NPCM_FIU_DRD_CFG_RDCMD		GENMASK(7, 0)
+#define NPCM_FIU_DRD_ADDSIZ_SHIFT	16
+#define NPCM_FIU_DRD_DBW_SHIFT		12
+#define NPCM_FIU_DRD_ACCTYPE_SHIFT	8
+
+/* FIU Direct Write Configuration Register */
+#define NPCM_FIU_DWR_CFG_LCK		BIT(31)
+#define NPCM_FIU_DWR_CFG_W_BURST	GENMASK(25, 24)
+#define NPCM_FIU_DWR_CFG_ADDSIZ		GENMASK(17, 16)
+#define NPCM_FIU_DWR_CFG_ABPCK		GENMASK(11, 10)
+#define NPCM_FIU_DWR_CFG_DBPCK		GENMASK(9, 8)
+#define NPCM_FIU_DWR_CFG_WRCMD		GENMASK(7, 0)
+#define NPCM_FIU_DWR_ADDSIZ_SHIFT	16
+#define NPCM_FIU_DWR_ABPCK_SHIFT	10
+#define NPCM_FIU_DWR_DBPCK_SHIFT	8
+
+/* FIU UMA Configuration Register */
+#define NPCM_FIU_UMA_CFG_LCK		BIT(31)
+#define NPCM_FIU_UMA_CFG_CMMLCK		BIT(30)
+#define NPCM_FIU_UMA_CFG_RDATSIZ	GENMASK(28, 24)
+#define NPCM_FIU_UMA_CFG_DBSIZ		GENMASK(23, 21)
+#define NPCM_FIU_UMA_CFG_WDATSIZ	GENMASK(20, 16)
+#define NPCM_FIU_UMA_CFG_ADDSIZ		GENMASK(13, 11)
+#define NPCM_FIU_UMA_CFG_CMDSIZ		BIT(10)
+#define NPCM_FIU_UMA_CFG_RDBPCK		GENMASK(9, 8)
+#define NPCM_FIU_UMA_CFG_DBPCK		GENMASK(7, 6)
+#define NPCM_FIU_UMA_CFG_WDBPCK		GENMASK(5, 4)
+#define NPCM_FIU_UMA_CFG_ADBPCK		GENMASK(3, 2)
+#define NPCM_FIU_UMA_CFG_CMBPCK		GENMASK(1, 0)
+#define NPCM_FIU_UMA_CFG_ADBPCK_SHIFT	2
+#define NPCM_FIU_UMA_CFG_WDBPCK_SHIFT	4
+#define NPCM_FIU_UMA_CFG_DBPCK_SHIFT	6
+#define NPCM_FIU_UMA_CFG_RDBPCK_SHIFT	8
+#define NPCM_FIU_UMA_CFG_ADDSIZ_SHIFT	11
+#define NPCM_FIU_UMA_CFG_WDATSIZ_SHIFT	16
+#define NPCM_FIU_UMA_CFG_DBSIZ_SHIFT	21
+#define NPCM_FIU_UMA_CFG_RDATSIZ_SHIFT	24
+
+/* FIU UMA Control and Status Register */
+#define NPCM_FIU_UMA_CTS_RDYIE		BIT(25)
+#define NPCM_FIU_UMA_CTS_RDYST		BIT(24)
+#define NPCM_FIU_UMA_CTS_SW_CS		BIT(16)
+#define NPCM_FIU_UMA_CTS_DEV_NUM	GENMASK(9, 8)
+#define NPCM_FIU_UMA_CTS_EXEC_DONE	BIT(0)
+#define NPCM_FIU_UMA_CTS_DEV_NUM_SHIFT	8
+
+/* FIU UMA Command Register */
+#define NPCM_FIU_UMA_CMD_DUM3		GENMASK(31, 24)
+#define NPCM_FIU_UMA_CMD_DUM2		GENMASK(23, 16)
+#define NPCM_FIU_UMA_CMD_DUM1		GENMASK(15, 8)
+#define NPCM_FIU_UMA_CMD_CMD		GENMASK(7, 0)
+
+/* FIU UMA Address Register */
+#define NPCM_FIU_UMA_ADDR_UMA_ADDR	GENMASK(31, 0)
+#define NPCM_FIU_UMA_ADDR_AB3		GENMASK(31, 24)
+#define NPCM_FIU_UMA_ADDR_AB2		GENMASK(23, 16)
+#define NPCM_FIU_UMA_ADDR_AB1		GENMASK(15, 8)
+#define NPCM_FIU_UMA_ADDR_AB0		GENMASK(7, 0)
+
+/* FIU UMA Write Data Bytes 0-3 Register */
+#define NPCM_FIU_UMA_DW0_WB3		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DW0_WB2		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DW0_WB1		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DW0_WB0		GENMASK(7, 0)
+
+/* FIU UMA Write Data Bytes 4-7 Register */
+#define NPCM_FIU_UMA_DW1_WB7		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DW1_WB6		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DW1_WB5		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DW1_WB4		GENMASK(7, 0)
+
+/* FIU UMA Write Data Bytes 8-11 Register */
+#define NPCM_FIU_UMA_DW2_WB11		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DW2_WB10		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DW2_WB9		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DW2_WB8		GENMASK(7, 0)
+
+/* FIU UMA Write Data Bytes 12-15 Register */
+#define NPCM_FIU_UMA_DW3_WB15		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DW3_WB14		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DW3_WB13		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DW3_WB12		GENMASK(7, 0)
+
+/* FIU UMA Read Data Bytes 0-3 Register */
+#define NPCM_FIU_UMA_DR0_RB3		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DR0_RB2		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DR0_RB1		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DR0_RB0		GENMASK(7, 0)
+
+/* FIU UMA Read Data Bytes 4-7 Register */
+#define NPCM_FIU_UMA_DR1_RB15		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DR1_RB14		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DR1_RB13		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DR1_RB12		GENMASK(7, 0)
+
+/* FIU UMA Read Data Bytes 8-11 Register */
+#define NPCM_FIU_UMA_DR2_RB15		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DR2_RB14		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DR2_RB13		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DR2_RB12		GENMASK(7, 0)
+
+/* FIU UMA Read Data Bytes 12-15 Register */
+#define NPCM_FIU_UMA_DR3_RB15		GENMASK(31, 24)
+#define NPCM_FIU_UMA_DR3_RB14		GENMASK(23, 16)
+#define NPCM_FIU_UMA_DR3_RB13		GENMASK(15, 8)
+#define NPCM_FIU_UMA_DR3_RB12		GENMASK(7, 0)
+
+/* FIU Read Mode */
+enum {
+	DRD_SINGLE_WIRE_MODE	= 0,
+	DRD_DUAL_IO_MODE	= 1,
+	DRD_QUAD_IO_MODE	= 2,
+	DRD_SPI_X_MODE		= 3,
+};
+
+enum {
+	DWR_ABPCK_BIT_PER_CLK	= 0,
+	DWR_ABPCK_2_BIT_PER_CLK	= 1,
+	DWR_ABPCK_4_BIT_PER_CLK	= 2,
+};
+
+enum {
+	DWR_DBPCK_BIT_PER_CLK	= 0,
+	DWR_DBPCK_2_BIT_PER_CLK	= 1,
+	DWR_DBPCK_4_BIT_PER_CLK	= 2,
+};
+
+#define NPCM_FIU_DRD_16_BYTE_BURST	0x3000000
+#define NPCM_FIU_DWR_16_BYTE_BURST	0x3000000
+
+#define MAP_SIZE_128MB			0x8000000
+#define MAP_SIZE_16MB			0x1000000
+#define MAP_SIZE_8MB			0x800000
+
+#define NUM_BITS_IN_BYTE		8
+#define FIU_DRD_MAX_DUMMY_NUMBER	3
+#define NPCM_MAX_CHIP_NUM		4
+#define CHUNK_SIZE			16
+#define UMA_MICRO_SEC_TIMEOUT		150
+
+enum {
+	FIU0 = 0,
+	FIU3,
+	FIUX,
+};
+
+struct npcm_fiu_info {
+	char *name;
+	u32 fiu_id;
+	u32 max_map_size;
+	u32 max_cs;
+};
+
+struct fiu_data {
+	const struct npcm_fiu_info *npcm_fiu_data_info;
+	int fiu_max;
+};
+
+static const struct npcm_fiu_info npxm7xx_fiu_info[] = {
+	{.name = "FIU0", .fiu_id = FIU0,
+		.max_map_size = MAP_SIZE_128MB, .max_cs = 2},
+	{.name = "FIU3", .fiu_id = FIU3,
+		.max_map_size = MAP_SIZE_128MB, .max_cs = 4},
+	{.name = "FIUX", .fiu_id = FIUX,
+		.max_map_size = MAP_SIZE_16MB, .max_cs = 2} };
+
+static const struct fiu_data npxm7xx_fiu_data = {
+	.npcm_fiu_data_info = npxm7xx_fiu_info,
+	.fiu_max = 3,
+};
+
+struct npcm_fiu_spi;
+
+struct npcm_fiu_chip {
+	void __iomem *flash_region_mapped_ptr;
+	struct npcm_fiu_spi *fiu;
+	unsigned long clkrate;
+	u32 chipselect;
+};
+
+struct npcm_fiu_spi {
+	struct npcm_fiu_chip chip[NPCM_MAX_CHIP_NUM];
+	const struct npcm_fiu_info *info;
+	struct spi_mem_op drd_op;
+	struct resource *res_mem;
+	struct regmap *regmap;
+	unsigned long clkrate;
+	struct device *dev;
+	struct clk *clk;
+	bool spix_mode;
+};
+
+static const struct regmap_config npcm_mtd_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = NPCM_FIU_MAX_REG_LIMIT,
+};
+
+static void npcm_fiu_set_drd(struct npcm_fiu_spi *fiu,
+			     const struct spi_mem_op *op)
+{
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
+			   NPCM_FIU_DRD_CFG_ACCTYPE,
+			   ilog2(op->addr.buswidth) <<
+			   NPCM_FIU_DRD_ACCTYPE_SHIFT);
+	fiu->drd_op.addr.buswidth = op->addr.buswidth;
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
+			   NPCM_FIU_DRD_CFG_DBW,
+			   ((op->dummy.nbytes * ilog2(op->addr.buswidth))
+			    / NUM_BITS_IN_BYTE) << NPCM_FIU_DRD_DBW_SHIFT);
+	fiu->drd_op.dummy.nbytes = op->dummy.nbytes;
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
+			   NPCM_FIU_DRD_CFG_RDCMD, op->cmd.opcode);
+	fiu->drd_op.cmd.opcode = op->cmd.opcode;
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
+			   NPCM_FIU_DRD_CFG_ADDSIZ,
+			   (op->addr.nbytes - 3) << NPCM_FIU_DRD_ADDSIZ_SHIFT);
+	fiu->drd_op.addr.nbytes = op->addr.nbytes;
+}
+
+static ssize_t npcm_fiu_direct_read(struct spi_mem_dirmap_desc *desc,
+				    u64 offs, size_t len, void *buf)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(desc->mem->spi->master);
+	struct npcm_fiu_chip *chip = &fiu->chip[desc->mem->spi->chip_select];
+	void __iomem *src = (void __iomem *)(chip->flash_region_mapped_ptr +
+					     offs);
+	u8 *buf_rx = buf;
+	u32 i;
+
+	if (fiu->spix_mode) {
+		for (i = 0 ; i < len ; i++)
+			*(buf_rx + i) = ioread8(src + i);
+	} else {
+		if (desc->info.op_tmpl.addr.buswidth != fiu->drd_op.addr.buswidth ||
+		    desc->info.op_tmpl.dummy.nbytes != fiu->drd_op.dummy.nbytes ||
+		    desc->info.op_tmpl.cmd.opcode != fiu->drd_op.cmd.opcode ||
+		    desc->info.op_tmpl.addr.nbytes != fiu->drd_op.addr.nbytes)
+			npcm_fiu_set_drd(fiu, &desc->info.op_tmpl);
+
+		memcpy_fromio(buf_rx, src, len);
+	}
+
+	return len;
+}
+
+static ssize_t npcm_fiu_direct_write(struct spi_mem_dirmap_desc *desc,
+				     u64 offs, size_t len, const void *buf)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(desc->mem->spi->master);
+	struct npcm_fiu_chip *chip = &fiu->chip[desc->mem->spi->chip_select];
+	void __iomem *dst = (void __iomem *)(chip->flash_region_mapped_ptr +
+					     offs);
+	const u8 *buf_tx = buf;
+	u32 i;
+
+	if (fiu->spix_mode)
+		for (i = 0 ; i < len ; i++)
+			iowrite8(*(buf_tx + i), dst + i);
+	else
+		memcpy_toio(dst, buf_tx, len);
+
+	return len;
+}
+
+static int npcm_fiu_uma_read(struct spi_mem *mem,
+			     const struct spi_mem_op *op, u32 addr,
+			      bool is_address_size, u8 *data, u32 data_size)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(mem->spi->master);
+	u32 uma_cfg = BIT(10);
+	u32 data_reg[4];
+	int ret;
+	u32 val;
+	u32 i;
+
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			   NPCM_FIU_UMA_CTS_DEV_NUM,
+			   (mem->spi->chip_select <<
+			    NPCM_FIU_UMA_CTS_DEV_NUM_SHIFT));
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CMD,
+			   NPCM_FIU_UMA_CMD_CMD, op->cmd.opcode);
+
+	if (is_address_size) {
+		uma_cfg |= ilog2(op->cmd.buswidth);
+		uma_cfg |= ilog2(op->addr.buswidth)
+			<< NPCM_FIU_UMA_CFG_ADBPCK_SHIFT;
+		uma_cfg |= ilog2(op->dummy.buswidth)
+			<< NPCM_FIU_UMA_CFG_DBPCK_SHIFT;
+		uma_cfg |= ilog2(op->data.buswidth)
+			<< NPCM_FIU_UMA_CFG_RDBPCK_SHIFT;
+		uma_cfg |= op->dummy.nbytes << NPCM_FIU_UMA_CFG_DBSIZ_SHIFT;
+		uma_cfg |= op->addr.nbytes << NPCM_FIU_UMA_CFG_ADDSIZ_SHIFT;
+		regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR, addr);
+	} else {
+		regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR, 0x0);
+	}
+
+	uma_cfg |= data_size << NPCM_FIU_UMA_CFG_RDATSIZ_SHIFT;
+	regmap_write(fiu->regmap, NPCM_FIU_UMA_CFG, uma_cfg);
+	regmap_write_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			  NPCM_FIU_UMA_CTS_EXEC_DONE,
+			  NPCM_FIU_UMA_CTS_EXEC_DONE);
+	ret = regmap_read_poll_timeout(fiu->regmap, NPCM_FIU_UMA_CTS, val,
+				       (!(val & NPCM_FIU_UMA_CTS_EXEC_DONE)), 0,
+				       UMA_MICRO_SEC_TIMEOUT);
+	if (ret)
+		return ret;
+
+	if (data_size) {
+		for (i = 0; i < DIV_ROUND_UP(data_size, 4); i++)
+			regmap_read(fiu->regmap, NPCM_FIU_UMA_DR0 + (i * 4),
+				    &data_reg[i]);
+		memcpy(data, data_reg, data_size);
+	}
+
+	return 0;
+}
+
+static int npcm_fiu_uma_write(struct spi_mem *mem,
+			      const struct spi_mem_op *op, u8 cmd,
+			      bool is_address_size, u8 *data, u32 data_size)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(mem->spi->master);
+	u32 uma_cfg = BIT(10);
+	u32 data_reg[4] = {0};
+	u32 val;
+	u32 i;
+
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			   NPCM_FIU_UMA_CTS_DEV_NUM,
+			   (mem->spi->chip_select <<
+			    NPCM_FIU_UMA_CTS_DEV_NUM_SHIFT));
+
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CMD,
+			   NPCM_FIU_UMA_CMD_CMD, cmd);
+
+	if (data_size) {
+		memcpy(data_reg, data, data_size);
+		for (i = 0; i < DIV_ROUND_UP(data_size, 4); i++)
+			regmap_write(fiu->regmap, NPCM_FIU_UMA_DW0 + (i * 4),
+				     data_reg[i]);
+	}
+
+	if (is_address_size) {
+		uma_cfg |= ilog2(op->cmd.buswidth);
+		uma_cfg |= ilog2(op->addr.buswidth) <<
+			NPCM_FIU_UMA_CFG_ADBPCK_SHIFT;
+		uma_cfg |= ilog2(op->data.buswidth) <<
+			NPCM_FIU_UMA_CFG_WDBPCK_SHIFT;
+		uma_cfg |= op->addr.nbytes << NPCM_FIU_UMA_CFG_ADDSIZ_SHIFT;
+		regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR, op->addr.val);
+	} else {
+		regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR, 0x0);
+	}
+
+	uma_cfg |= (data_size << NPCM_FIU_UMA_CFG_WDATSIZ_SHIFT);
+	regmap_write(fiu->regmap, NPCM_FIU_UMA_CFG, uma_cfg);
+
+	regmap_write_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			  NPCM_FIU_UMA_CTS_EXEC_DONE,
+			  NPCM_FIU_UMA_CTS_EXEC_DONE);
+
+	return regmap_read_poll_timeout(fiu->regmap, NPCM_FIU_UMA_CTS, val,
+				       (!(val & NPCM_FIU_UMA_CTS_EXEC_DONE)), 0,
+					UMA_MICRO_SEC_TIMEOUT);
+}
+
+static int npcm_fiu_manualwrite(struct spi_mem *mem,
+				const struct spi_mem_op *op)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(mem->spi->master);
+	u8 *data = (u8 *)op->data.buf.out;
+	u32 num_data_chunks;
+	u32 remain_data;
+	u32 idx = 0;
+	int ret;
+
+	num_data_chunks  = op->data.nbytes / CHUNK_SIZE;
+	remain_data  = op->data.nbytes % CHUNK_SIZE;
+
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			   NPCM_FIU_UMA_CTS_DEV_NUM,
+			   (mem->spi->chip_select <<
+			    NPCM_FIU_UMA_CTS_DEV_NUM_SHIFT));
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			   NPCM_FIU_UMA_CTS_SW_CS, 0);
+
+	ret = npcm_fiu_uma_write(mem, op, op->cmd.opcode, true, NULL, 0);
+	if (ret)
+		return ret;
+
+	/* Starting the data writing loop in multiples of 8 */
+	for (idx = 0; idx < num_data_chunks; ++idx) {
+		ret = npcm_fiu_uma_write(mem, op, data[0], false,
+					 &data[1], CHUNK_SIZE - 1);
+		if (ret)
+			return ret;
+
+		data += CHUNK_SIZE;
+	}
+
+	/* Handling chunk remains */
+	if (remain_data > 0) {
+		ret = npcm_fiu_uma_write(mem, op, data[0], false,
+					 &data[1], remain_data - 1);
+		if (ret)
+			return ret;
+	}
+
+	regmap_update_bits(fiu->regmap, NPCM_FIU_UMA_CTS,
+			   NPCM_FIU_UMA_CTS_SW_CS, NPCM_FIU_UMA_CTS_SW_CS);
+
+	return 0;
+}
+
+static int npcm_fiu_read(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	u8 *data = op->data.buf.in;
+	int i, readlen, currlen;
+	size_t retlen = 0;
+	u8 *buf_ptr;
+	u32 addr;
+	int ret;
+
+	i = 0;
+	currlen = op->data.nbytes;
+
+	do {
+		addr = ((u32)op->addr.val + i);
+		if (currlen < 16)
+			readlen = currlen;
+		else
+			readlen = 16;
+
+		buf_ptr = data + i;
+		ret = npcm_fiu_uma_read(mem, op, addr, true, buf_ptr,
+					readlen);
+		if (ret)
+			return ret;
+
+		i += readlen;
+		currlen -= 16;
+	} while (currlen > 0);
+
+	retlen = i;
+
+	return 0;
+}
+
+static void npcm_fiux_set_direct_wr(struct npcm_fiu_spi *fiu)
+{
+	regmap_write(fiu->regmap, NPCM_FIU_DWR_CFG,
+		     NPCM_FIU_DWR_16_BYTE_BURST);
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DWR_CFG,
+			   NPCM_FIU_DWR_CFG_ABPCK,
+			   DWR_ABPCK_4_BIT_PER_CLK << NPCM_FIU_DWR_ABPCK_SHIFT);
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DWR_CFG,
+			   NPCM_FIU_DWR_CFG_DBPCK,
+			   DWR_DBPCK_4_BIT_PER_CLK << NPCM_FIU_DWR_DBPCK_SHIFT);
+}
+
+static void npcm_fiux_set_direct_rd(struct npcm_fiu_spi *fiu)
+{
+	u32 rx_dummy = 0;
+
+	regmap_write(fiu->regmap, NPCM_FIU_DRD_CFG,
+		     NPCM_FIU_DRD_16_BYTE_BURST);
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
+			   NPCM_FIU_DRD_CFG_ACCTYPE,
+			   DRD_SPI_X_MODE << NPCM_FIU_DRD_ACCTYPE_SHIFT);
+	regmap_update_bits(fiu->regmap, NPCM_FIU_DRD_CFG,
+			   NPCM_FIU_DRD_CFG_DBW,
+			   rx_dummy << NPCM_FIU_DRD_DBW_SHIFT);
+}
+
+static int npcm_fiu_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(mem->spi->master);
+	struct npcm_fiu_chip *chip = &fiu->chip[mem->spi->chip_select];
+	int ret = 0;
+	u8 *buf;
+
+	dev_dbg(fiu->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n",
+		op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
+		op->dummy.buswidth, op->data.buswidth, op->addr.val,
+		op->data.nbytes);
+
+	if (fiu->spix_mode)
+		return -ENOTSUPP;
+
+	if (fiu->clkrate != chip->clkrate) {
+		ret = clk_set_rate(fiu->clk, chip->clkrate);
+		if (ret < 0)
+			dev_warn(fiu->dev, "Failed setting %lu frequancy, stay at %lu frequancy\n", chip->clkrate, fiu->clkrate);
+		else
+			fiu->clkrate = chip->clkrate;
+	}
+
+	if (op->data.dir == SPI_MEM_DATA_IN) {
+		if (!op->addr.nbytes) {
+			buf = op->data.buf.in;
+			ret = npcm_fiu_uma_read(mem, op, op->addr.val, false,
+						buf, op->data.nbytes);
+		} else {
+			ret = npcm_fiu_read(mem, op);
+		}
+	}
+
+	if (op->data.dir == SPI_MEM_DATA_OUT) {
+		if (!op->addr.nbytes) {
+			buf = (u8 *)op->data.buf.out;
+			ret = npcm_fiu_uma_write(mem, op, op->cmd.opcode, false,
+						 buf, op->data.nbytes);
+		} else {
+			ret = npcm_fiu_manualwrite(mem, op);
+		}
+	}
+
+	return ret;
+}
+
+static int npcm_fiu_dirmap_create(struct spi_mem_dirmap_desc *desc)
+{
+	struct npcm_fiu_spi *fiu =
+		spi_controller_get_devdata(desc->mem->spi->master);
+	struct npcm_fiu_chip *chip = &fiu->chip[desc->mem->spi->chip_select];
+	struct regmap *gcr_regmap;
+
+	if (!fiu->res_mem) {
+		dev_warn(fiu->dev, "Reserved memory not defined, direct read disabled\n");
+		desc->nodirmap = true;
+		return 0;
+	}
+
+	if (!fiu->spix_mode &&
+	    desc->info.op_tmpl.data.dir == SPI_MEM_DATA_OUT) {
+		desc->nodirmap = true;
+		return 0;
+	}
+
+	if (!chip->flash_region_mapped_ptr) {
+		chip->flash_region_mapped_ptr =
+			devm_ioremap_nocache(fiu->dev, (fiu->res_mem->start +
+						   (fiu->info->max_map_size *
+						    desc->mem->spi->chip_select)),
+					     (u32)desc->info.length);
+		if (!chip->flash_region_mapped_ptr) {
+			dev_warn(fiu->dev, "Error mapping memory region, direct read disabled\n");
+			desc->nodirmap = true;
+			return 0;
+		}
+	}
+
+	if (of_device_is_compatible(fiu->dev->of_node, "nuvoton,npcm750-fiu")) {
+		gcr_regmap =
+			syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
+		if (IS_ERR(gcr_regmap)) {
+			dev_warn(fiu->dev, "Didn't find nuvoton,npcm750-gcr, direct read disabled\n");
+			desc->nodirmap = true;
+			return 0;
+		}
+		regmap_update_bits(gcr_regmap, NPCM7XX_INTCR3_OFFSET,
+				   NPCM7XX_INTCR3_FIU_FIX,
+				   NPCM7XX_INTCR3_FIU_FIX);
+	}
+
+	if (desc->info.op_tmpl.data.dir == SPI_MEM_DATA_IN) {
+		if (!fiu->spix_mode)
+			npcm_fiu_set_drd(fiu, &desc->info.op_tmpl);
+		else
+			npcm_fiux_set_direct_rd(fiu);
+
+	} else {
+		npcm_fiux_set_direct_wr(fiu);
+	}
+
+	return 0;
+}
+
+static int npcm_fiu_setup(struct spi_device *spi)
+{
+	struct spi_controller *ctrl = spi->master;
+	struct npcm_fiu_spi *fiu = spi_controller_get_devdata(ctrl);
+	struct npcm_fiu_chip *chip;
+
+	chip = &fiu->chip[spi->chip_select];
+	chip->fiu = fiu;
+	chip->chipselect = spi->chip_select;
+	chip->clkrate = spi->max_speed_hz;
+
+	fiu->clkrate = clk_get_rate(fiu->clk);
+
+	return 0;
+}
+
+static const struct spi_controller_mem_ops npcm_fiu_mem_ops = {
+	.exec_op = npcm_fiu_exec_op,
+	.dirmap_create = npcm_fiu_dirmap_create,
+	.dirmap_read = npcm_fiu_direct_read,
+	.dirmap_write = npcm_fiu_direct_write,
+};
+
+static const struct of_device_id npcm_fiu_dt_ids[] = {
+	{ .compatible = "nuvoton,npcm750-fiu", .data = &npxm7xx_fiu_data  },
+	{ /* sentinel */ }
+};
+
+static int npcm_fiu_probe(struct platform_device *pdev)
+{
+	const struct fiu_data *fiu_data_match;
+	const struct of_device_id *match;
+	struct device *dev = &pdev->dev;
+	struct spi_controller *ctrl;
+	struct npcm_fiu_spi *fiu;
+	void __iomem *regbase;
+	struct resource *res;
+	int ret;
+	int id;
+
+	ctrl = spi_alloc_master(dev, sizeof(*fiu));
+	if (!ctrl)
+		return -ENOMEM;
+
+	fiu = spi_controller_get_devdata(ctrl);
+
+	match = of_match_device(npcm_fiu_dt_ids, dev);
+	if (!match || !match->data) {
+		dev_err(dev, "No compatible OF match\n");
+		return -ENODEV;
+	}
+
+	fiu_data_match = match->data;
+	id = of_alias_get_id(dev->of_node, "fiu");
+	if (id < 0 || id >= fiu_data_match->fiu_max) {
+		dev_err(dev, "Invalid platform device id: %d\n", id);
+		return -EINVAL;
+	}
+
+	fiu->info = &fiu_data_match->npcm_fiu_data_info[id];
+
+	platform_set_drvdata(pdev, fiu);
+	fiu->dev = dev;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control");
+	regbase = devm_ioremap_resource(dev, res);
+	if (IS_ERR(regbase))
+		return PTR_ERR(regbase);
+
+	fiu->regmap = devm_regmap_init_mmio(dev, regbase,
+					    &npcm_mtd_regmap_config);
+	if (IS_ERR(fiu->regmap)) {
+		dev_err(dev, "Failed to create regmap\n");
+		return PTR_ERR(fiu->regmap);
+	}
+
+	fiu->res_mem = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						    "memory");
+	fiu->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(fiu->clk))
+		return PTR_ERR(fiu->clk);
+
+	fiu->spix_mode = of_property_read_bool(dev->of_node, "spix-mode");
+
+	platform_set_drvdata(pdev, fiu);
+	clk_prepare_enable(fiu->clk);
+
+	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD
+		| SPI_TX_DUAL | SPI_TX_QUAD;
+	ctrl->setup = npcm_fiu_setup;
+	ctrl->bus_num = -1;
+	ctrl->mem_ops = &npcm_fiu_mem_ops;
+	ctrl->num_chipselect = fiu->info->max_cs;
+	ctrl->dev.of_node = dev->of_node;
+
+	ret = devm_spi_register_master(dev, ctrl);
+	if (ret)
+		return ret;
+
+	dev_info(dev, "NPCM %s probe succeed\n", fiu->info->name);
+
+	return 0;
+}
+
+static int npcm_fiu_remove(struct platform_device *pdev)
+{
+	struct npcm_fiu_spi *fiu = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(fiu->clk);
+	return 0;
+}
+
+MODULE_DEVICE_TABLE(of, npcm_fiu_dt_ids);
+
+static struct platform_driver npcm_fiu_driver = {
+	.driver = {
+		.name	= "NPCM-FIU",
+		.bus	= &platform_bus_type,
+		.of_match_table = npcm_fiu_dt_ids,
+	},
+	.probe      = npcm_fiu_probe,
+	.remove	    = npcm_fiu_remove,
+};
+module_platform_driver(npcm_fiu_driver);
+
+MODULE_DESCRIPTION("Nuvoton FLASH Interface Unit SPI Controller Driver");
+MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
+MODULE_LICENSE("GPL v2");
