// 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;
	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);

	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 || op->addr.nbytes > 4)
		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 frequency, stay at %lu frequency\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);
		}
	} else  {
		if (!op->addr.nbytes && !op->data.nbytes)
			ret = npcm_fiu_uma_write(mem, op, op->cmd.opcode, false,
						 NULL, 0);
		if (op->addr.nbytes && !op->data.nbytes) {
			int i;
			u8 buf_addr[4];
			u32 addr = op->addr.val;

			for (i = op->addr.nbytes - 1; i >= 0; i--) {
				buf_addr[i] = addr & 0xff;
				addr >>= 8;
			}
			ret = npcm_fiu_uma_write(mem, op, op->cmd.opcode, false,
						 buf_addr, op->addr.nbytes);
		}
		if (!op->addr.nbytes && op->data.nbytes)
			ret = npcm_fiu_uma_write(mem, op, op->cmd.opcode, false,
						 (u8 *)op->data.buf.out,
						 op->data.nbytes);
		if (op->addr.nbytes && op->data.nbytes)
			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(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,
					       "nuvoton,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;

	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");