root/drivers/spi/spi-npcm-fiu.c
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Nuvoton Technology corporation.

#include <linux/bits.h>
#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.h>
#include <linux/minmax.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_CFG                    0x78
#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 Configuration Register */
#define NPCM_FIU_CFG_FIU_FIX            BIT(31)

/* 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 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,
        FIU1,
};

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 npcm7xx_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 npcm7xx_fiu_data = {
        .npcm_fiu_data_info = npcm7xx_fiu_info,
        .fiu_max = 3,
};

static const struct npcm_fiu_info npxm8xx_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},
        {.name = "FIU1", .fiu_id = FIU1,
                .max_map_size = MAP_SIZE_16MB, .max_cs = 4} };

static const struct fiu_data npxm8xx_fiu_data = {
        .npcm_fiu_data_info = npxm8xx_fiu_info,
        .fiu_max = 4,
};

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 << 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->controller);
        struct npcm_fiu_chip *chip = &fiu->chip[spi_get_chipselect(desc->mem->spi, 0)];
        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->controller);
        struct npcm_fiu_chip *chip = &fiu->chip[spi_get_chipselect(desc->mem->spi, 0)];
        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->controller);
        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,
                           (spi_get_chipselect(mem->spi, 0) <<
                            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;
                if (op->dummy.nbytes)
                        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->controller);
        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,
                           (spi_get_chipselect(mem->spi, 0) <<
                            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->controller);
        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,
                           (spi_get_chipselect(mem->spi, 0) <<
                            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);
                readlen = min_t(int, currlen, 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->controller);
        struct npcm_fiu_chip *chip = &fiu->chip[spi_get_chipselect(mem->spi, 0)];
        int ret = 0;
        u8 *buf;

        if (fiu->spix_mode || op->addr.nbytes > 4)
                return -EOPNOTSUPP;

        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->controller);
        struct npcm_fiu_chip *chip = &fiu->chip[spi_get_chipselect(desc->mem->spi, 0)];
        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 *
                                                    spi_get_chipselect(desc->mem->spi, 0))),
                                             (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);
        } else {
                regmap_update_bits(fiu->regmap, NPCM_FIU_CFG,
                                   NPCM_FIU_CFG_FIU_FIX,
                                   NPCM_FIU_CFG_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->controller;
        struct npcm_fiu_spi *fiu = spi_controller_get_devdata(ctrl);
        struct npcm_fiu_chip *chip;

        chip = &fiu->chip[spi_get_chipselect(spi, 0)];
        chip->fiu = fiu;
        chip->chipselect = spi_get_chipselect(spi, 0);
        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 = &npcm7xx_fiu_data  },
        { .compatible = "nuvoton,npcm845-fiu", .data = &npxm8xx_fiu_data  },
        { /* sentinel */ }
};

static int npcm_fiu_probe(struct platform_device *pdev)
{
        const struct fiu_data *fiu_data_match;
        struct device *dev = &pdev->dev;
        struct spi_controller *ctrl;
        struct npcm_fiu_spi *fiu;
        void __iomem *regbase;
        int id;

        ctrl = devm_spi_alloc_host(dev, sizeof(*fiu));
        if (!ctrl)
                return -ENOMEM;

        fiu = spi_controller_get_devdata(ctrl);

        fiu_data_match = of_device_get_match_data(dev);
        if (!fiu_data_match) {
                dev_err(dev, "No compatible OF match\n");
                return -ENODEV;
        }

        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;

        regbase = devm_platform_ioremap_resource_byname(pdev, "control");
        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_enabled(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);

        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;

        return devm_spi_register_controller(dev, ctrl);
}

static void npcm_fiu_remove(struct platform_device *pdev)
{
}

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");