// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Xilinx Zynq UltraScale+ MPSoC Quad-SPI (QSPI) controller driver
 * (host mode only)
 *
 * Copyright (C) 2009 - 2015 Xilinx, Inc.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/firmware/xlnx-zynqmp.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/spi/spi-mem.h>

/* Generic QSPI register offsets */
#define GQSPI_CONFIG_OFST               0x00000100
#define GQSPI_ISR_OFST                  0x00000104
#define GQSPI_IDR_OFST                  0x0000010C
#define GQSPI_IER_OFST                  0x00000108
#define GQSPI_IMASK_OFST                0x00000110
#define GQSPI_EN_OFST                   0x00000114
#define GQSPI_TXD_OFST                  0x0000011C
#define GQSPI_RXD_OFST                  0x00000120
#define GQSPI_TX_THRESHOLD_OFST         0x00000128
#define GQSPI_RX_THRESHOLD_OFST         0x0000012C
#define IOU_TAPDLY_BYPASS_OFST          0x0000003C
#define GQSPI_LPBK_DLY_ADJ_OFST         0x00000138
#define GQSPI_GEN_FIFO_OFST             0x00000140
#define GQSPI_SEL_OFST                  0x00000144
#define GQSPI_GF_THRESHOLD_OFST         0x00000150
#define GQSPI_FIFO_CTRL_OFST            0x0000014C
#define GQSPI_QSPIDMA_DST_CTRL_OFST     0x0000080C
#define GQSPI_QSPIDMA_DST_SIZE_OFST     0x00000804
#define GQSPI_QSPIDMA_DST_STS_OFST      0x00000808
#define GQSPI_QSPIDMA_DST_I_STS_OFST    0x00000814
#define GQSPI_QSPIDMA_DST_I_EN_OFST     0x00000818
#define GQSPI_QSPIDMA_DST_I_DIS_OFST    0x0000081C
#define GQSPI_QSPIDMA_DST_I_MASK_OFST   0x00000820
#define GQSPI_QSPIDMA_DST_ADDR_OFST     0x00000800
#define GQSPI_QSPIDMA_DST_ADDR_MSB_OFST 0x00000828
#define GQSPI_DATA_DLY_ADJ_OFST         0x000001F8

/* GQSPI register bit masks */
#define GQSPI_SEL_MASK                          0x00000001
#define GQSPI_EN_MASK                           0x00000001
#define GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK        0x00000020
#define GQSPI_ISR_WR_TO_CLR_MASK                0x00000002
#define GQSPI_IDR_ALL_MASK                      0x00000FBE
#define GQSPI_CFG_MODE_EN_MASK                  0xC0000000
#define GQSPI_CFG_GEN_FIFO_START_MODE_MASK      0x20000000
#define GQSPI_CFG_ENDIAN_MASK                   0x04000000
#define GQSPI_CFG_EN_POLL_TO_MASK               0x00100000
#define GQSPI_CFG_WP_HOLD_MASK                  0x00080000
#define GQSPI_CFG_BAUD_RATE_DIV_MASK            0x00000038
#define GQSPI_CFG_CLK_PHA_MASK                  0x00000004
#define GQSPI_CFG_CLK_POL_MASK                  0x00000002
#define GQSPI_CFG_START_GEN_FIFO_MASK           0x10000000
#define GQSPI_GENFIFO_IMM_DATA_MASK             0x000000FF
#define GQSPI_GENFIFO_DATA_XFER                 0x00000100
#define GQSPI_GENFIFO_EXP                       0x00000200
#define GQSPI_GENFIFO_MODE_SPI                  0x00000400
#define GQSPI_GENFIFO_MODE_DUALSPI              0x00000800
#define GQSPI_GENFIFO_MODE_QUADSPI              0x00000C00
#define GQSPI_GENFIFO_MODE_MASK                 0x00000C00
#define GQSPI_GENFIFO_CS_LOWER                  0x00001000
#define GQSPI_GENFIFO_CS_UPPER                  0x00002000
#define GQSPI_GENFIFO_BUS_LOWER                 0x00004000
#define GQSPI_GENFIFO_BUS_UPPER                 0x00008000
#define GQSPI_GENFIFO_BUS_BOTH                  0x0000C000
#define GQSPI_GENFIFO_BUS_MASK                  0x0000C000
#define GQSPI_GENFIFO_TX                        0x00010000
#define GQSPI_GENFIFO_RX                        0x00020000
#define GQSPI_GENFIFO_STRIPE                    0x00040000
#define GQSPI_GENFIFO_POLL                      0x00080000
#define GQSPI_FIFO_CTRL_RST_RX_FIFO_MASK        0x00000004
#define GQSPI_FIFO_CTRL_RST_TX_FIFO_MASK        0x00000002
#define GQSPI_FIFO_CTRL_RST_GEN_FIFO_MASK       0x00000001
#define GQSPI_ISR_RXEMPTY_MASK                  0x00000800
#define GQSPI_ISR_GENFIFOFULL_MASK              0x00000400
#define GQSPI_ISR_GENFIFONOT_FULL_MASK          0x00000200
#define GQSPI_ISR_TXEMPTY_MASK                  0x00000100
#define GQSPI_ISR_GENFIFOEMPTY_MASK             0x00000080
#define GQSPI_ISR_RXFULL_MASK                   0x00000020
#define GQSPI_ISR_RXNEMPTY_MASK                 0x00000010
#define GQSPI_ISR_TXFULL_MASK                   0x00000008
#define GQSPI_ISR_TXNOT_FULL_MASK               0x00000004
#define GQSPI_ISR_POLL_TIME_EXPIRE_MASK         0x00000002
#define GQSPI_IER_TXNOT_FULL_MASK               0x00000004
#define GQSPI_IER_RXEMPTY_MASK                  0x00000800
#define GQSPI_IER_POLL_TIME_EXPIRE_MASK         0x00000002
#define GQSPI_IER_RXNEMPTY_MASK                 0x00000010
#define GQSPI_IER_GENFIFOEMPTY_MASK             0x00000080
#define GQSPI_IER_TXEMPTY_MASK                  0x00000100
#define GQSPI_QSPIDMA_DST_INTR_ALL_MASK         0x000000FE
#define GQSPI_QSPIDMA_DST_STS_WTC               0x0000E000
#define GQSPI_CFG_MODE_EN_DMA_MASK              0x80000000
#define GQSPI_ISR_IDR_MASK                      0x00000994
#define GQSPI_QSPIDMA_DST_I_EN_DONE_MASK        0x00000002
#define GQSPI_QSPIDMA_DST_I_STS_DONE_MASK       0x00000002
#define GQSPI_IRQ_MASK                          0x00000980

#define GQSPI_CFG_BAUD_RATE_DIV_SHIFT           3
#define GQSPI_GENFIFO_CS_SETUP                  0x4
#define GQSPI_GENFIFO_CS_HOLD                   0x3
#define GQSPI_TXD_DEPTH                         64
#define GQSPI_RX_FIFO_THRESHOLD                 32
#define GQSPI_RX_FIFO_FILL      (GQSPI_RX_FIFO_THRESHOLD * 4)
#define GQSPI_TX_FIFO_THRESHOLD_RESET_VAL       32
#define GQSPI_TX_FIFO_FILL      (GQSPI_TXD_DEPTH -\
                                GQSPI_TX_FIFO_THRESHOLD_RESET_VAL)
#define GQSPI_GEN_FIFO_THRESHOLD_RESET_VAL      0X10
#define GQSPI_QSPIDMA_DST_CTRL_RESET_VAL        0x803FFA00
#define GQSPI_SELECT_FLASH_CS_LOWER             0x1
#define GQSPI_SELECT_FLASH_CS_UPPER             0x2
#define GQSPI_SELECT_FLASH_CS_BOTH              0x3
#define GQSPI_SELECT_FLASH_BUS_LOWER            0x1
#define GQSPI_SELECT_FLASH_BUS_UPPER            0x2
#define GQSPI_SELECT_FLASH_BUS_BOTH             0x3
#define GQSPI_BAUD_DIV_MAX      7       /* Baud rate divisor maximum */
#define GQSPI_BAUD_DIV_SHIFT    2       /* Baud rate divisor shift */
#define GQSPI_SELECT_MODE_SPI           0x1
#define GQSPI_SELECT_MODE_DUALSPI       0x2
#define GQSPI_SELECT_MODE_QUADSPI       0x4
#define GQSPI_DMA_UNALIGN               0x3
#define GQSPI_DEFAULT_NUM_CS    1       /* Default number of chip selects */

#define GQSPI_MAX_NUM_CS        2       /* Maximum number of chip selects */

#define GQSPI_USE_DATA_DLY              0x1
#define GQSPI_USE_DATA_DLY_SHIFT        31
#define GQSPI_DATA_DLY_ADJ_VALUE        0x2
#define GQSPI_DATA_DLY_ADJ_SHIFT        28
#define GQSPI_LPBK_DLY_ADJ_DLY_1        0x1
#define GQSPI_LPBK_DLY_ADJ_DLY_1_SHIFT  0x3
#define TAP_DLY_BYPASS_LQSPI_RX_VALUE   0x1
#define TAP_DLY_BYPASS_LQSPI_RX_SHIFT   0x2

/* set to differentiate versal from zynqmp, 1=versal, 0=zynqmp */
#define QSPI_QUIRK_HAS_TAPDELAY         BIT(0)

#define GQSPI_FREQ_37_5MHZ      37500000
#define GQSPI_FREQ_40MHZ        40000000
#define GQSPI_FREQ_100MHZ       100000000
#define GQSPI_FREQ_150MHZ       150000000

#define SPI_AUTOSUSPEND_TIMEOUT         3000
enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};

/**
 * struct qspi_platform_data - zynqmp qspi platform data structure
 * @quirks:    Flags is used to identify the platform
 */
struct qspi_platform_data {
        u32 quirks;
};

/**
 * struct zynqmp_qspi - Defines qspi driver instance
 * @ctlr:               Pointer to the spi controller information
 * @regs:               Virtual address of the QSPI controller registers
 * @refclk:             Pointer to the peripheral clock
 * @pclk:               Pointer to the APB clock
 * @irq:                IRQ number
 * @dev:                Pointer to struct device
 * @txbuf:              Pointer to the TX buffer
 * @rxbuf:              Pointer to the RX buffer
 * @bytes_to_transfer:  Number of bytes left to transfer
 * @bytes_to_receive:   Number of bytes left to receive
 * @genfifocs:          Used for chip select
 * @genfifobus:         Used to select the upper or lower bus
 * @dma_rx_bytes:       Remaining bytes to receive by DMA mode
 * @dma_addr:           DMA address after mapping the kernel buffer
 * @genfifoentry:       Used for storing the genfifoentry instruction.
 * @mode:               Defines the mode in which QSPI is operating
 * @data_completion:    completion structure
 * @op_lock:            Operational lock
 * @speed_hz:          Current SPI bus clock speed in hz
 * @has_tapdelay:       Used for tapdelay register available in qspi
 */
struct zynqmp_qspi {
        struct spi_controller *ctlr;
        void __iomem *regs;
        struct clk *refclk;
        struct clk *pclk;
        int irq;
        struct device *dev;
        const void *txbuf;
        void *rxbuf;
        int bytes_to_transfer;
        int bytes_to_receive;
        u32 genfifocs;
        u32 genfifobus;
        u32 dma_rx_bytes;
        dma_addr_t dma_addr;
        u32 genfifoentry;
        enum mode_type mode;
        struct completion data_completion;
        struct mutex op_lock;
        u32 speed_hz;
        bool has_tapdelay;
};

/**
 * zynqmp_gqspi_read - For GQSPI controller read operation
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @offset:     Offset from where to read
 * Return:      Value at the offset
 */
static u32 zynqmp_gqspi_read(struct zynqmp_qspi *xqspi, u32 offset)
{
        return readl_relaxed(xqspi->regs + offset);
}

/**
 * zynqmp_gqspi_write - For GQSPI controller write operation
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @offset:     Offset where to write
 * @val:        Value to be written
 */
static inline void zynqmp_gqspi_write(struct zynqmp_qspi *xqspi, u32 offset,
                                      u32 val)
{
        writel_relaxed(val, (xqspi->regs + offset));
}

/**
 * zynqmp_gqspi_selecttarget - For selection of target device
 * @instanceptr:        Pointer to the zynqmp_qspi structure
 * @targetcs:   For chip select
 * @targetbus:  To check which bus is selected- upper or lower
 */
static void zynqmp_gqspi_selecttarget(struct zynqmp_qspi *instanceptr,
                                      u8 targetcs, u8 targetbus)
{
        /*
         * Bus and CS lines selected here will be updated in the instance and
         * used for subsequent GENFIFO entries during transfer.
         */

        /* Choose target select line */
        switch (targetcs) {
        case GQSPI_SELECT_FLASH_CS_BOTH:
                instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER |
                        GQSPI_GENFIFO_CS_UPPER;
                break;
        case GQSPI_SELECT_FLASH_CS_UPPER:
                instanceptr->genfifocs = GQSPI_GENFIFO_CS_UPPER;
                break;
        case GQSPI_SELECT_FLASH_CS_LOWER:
                instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER;
                break;
        default:
                dev_warn(instanceptr->dev, "Invalid target select\n");
        }

        /* Choose the bus */
        switch (targetbus) {
        case GQSPI_SELECT_FLASH_BUS_BOTH:
                instanceptr->genfifobus = GQSPI_GENFIFO_BUS_LOWER |
                        GQSPI_GENFIFO_BUS_UPPER;
                break;
        case GQSPI_SELECT_FLASH_BUS_UPPER:
                instanceptr->genfifobus = GQSPI_GENFIFO_BUS_UPPER;
                break;
        case GQSPI_SELECT_FLASH_BUS_LOWER:
                instanceptr->genfifobus = GQSPI_GENFIFO_BUS_LOWER;
                break;
        default:
                dev_warn(instanceptr->dev, "Invalid target bus\n");
        }
}

/**
 * zynqmp_qspi_set_tapdelay:   To configure qspi tap delays
 * @xqspi:             Pointer to the zynqmp_qspi structure
 * @baudrateval:       Buadrate to configure
 */
static void zynqmp_qspi_set_tapdelay(struct zynqmp_qspi *xqspi, u32 baudrateval)
{
        u32 tapdlybypass = 0, lpbkdlyadj = 0, datadlyadj = 0, clk_rate;
        u32 reqhz = 0;

        clk_rate = clk_get_rate(xqspi->refclk);
        reqhz = (clk_rate / (GQSPI_BAUD_DIV_SHIFT << baudrateval));

        if (!xqspi->has_tapdelay) {
                if (reqhz <= GQSPI_FREQ_40MHZ) {
                        zynqmp_pm_set_tapdelay_bypass(PM_TAPDELAY_QSPI,
                                                      PM_TAPDELAY_BYPASS_ENABLE);
                } else if (reqhz <= GQSPI_FREQ_100MHZ) {
                        zynqmp_pm_set_tapdelay_bypass(PM_TAPDELAY_QSPI,
                                                      PM_TAPDELAY_BYPASS_ENABLE);
                        lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
                        datadlyadj |= ((GQSPI_USE_DATA_DLY <<
                                        GQSPI_USE_DATA_DLY_SHIFT)
                                        | (GQSPI_DATA_DLY_ADJ_VALUE <<
                                                GQSPI_DATA_DLY_ADJ_SHIFT));
                } else if (reqhz <= GQSPI_FREQ_150MHZ) {
                        lpbkdlyadj |= GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK;
                }
        } else {
                if (reqhz <= GQSPI_FREQ_37_5MHZ) {
                        tapdlybypass |= (TAP_DLY_BYPASS_LQSPI_RX_VALUE <<
                                        TAP_DLY_BYPASS_LQSPI_RX_SHIFT);
                } else if (reqhz <= GQSPI_FREQ_100MHZ) {
                        tapdlybypass |= (TAP_DLY_BYPASS_LQSPI_RX_VALUE <<
                                        TAP_DLY_BYPASS_LQSPI_RX_SHIFT);
                        lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
                        datadlyadj |= (GQSPI_USE_DATA_DLY <<
                                        GQSPI_USE_DATA_DLY_SHIFT);
                } else if (reqhz <= GQSPI_FREQ_150MHZ) {
                        lpbkdlyadj |= (GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK
                                       | (GQSPI_LPBK_DLY_ADJ_DLY_1 <<
                                               GQSPI_LPBK_DLY_ADJ_DLY_1_SHIFT));
                }
                zynqmp_gqspi_write(xqspi,
                                   IOU_TAPDLY_BYPASS_OFST, tapdlybypass);
        }
        zynqmp_gqspi_write(xqspi, GQSPI_LPBK_DLY_ADJ_OFST, lpbkdlyadj);
        zynqmp_gqspi_write(xqspi, GQSPI_DATA_DLY_ADJ_OFST, datadlyadj);
}

/**
 * zynqmp_qspi_init_hw - Initialize the hardware
 * @xqspi:      Pointer to the zynqmp_qspi structure
 *
 * The default settings of the QSPI controller's configurable parameters on
 * reset are
 *      - Host mode
 *      - TX threshold set to 1
 *      - RX threshold set to 1
 *      - Flash memory interface mode enabled
 * This function performs the following actions
 *      - Disable and clear all the interrupts
 *      - Enable manual target select
 *      - Enable manual start
 *      - Deselect all the chip select lines
 *      - Set the little endian mode of TX FIFO
 *      - Set clock phase
 *      - Set clock polarity and
 *      - Enable the QSPI controller
 */
static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
{
        u32 config_reg, baud_rate_val = 0;
        ulong clk_rate;

        /* Select the GQSPI mode */
        zynqmp_gqspi_write(xqspi, GQSPI_SEL_OFST, GQSPI_SEL_MASK);
        /* Clear and disable interrupts */
        zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST,
                           zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST) |
                           GQSPI_ISR_WR_TO_CLR_MASK);
        /* Clear the DMA STS */
        zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
                           zynqmp_gqspi_read(xqspi,
                                             GQSPI_QSPIDMA_DST_I_STS_OFST));
        zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_STS_OFST,
                           zynqmp_gqspi_read(xqspi,
                                             GQSPI_QSPIDMA_DST_STS_OFST) |
                                             GQSPI_QSPIDMA_DST_STS_WTC);
        zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_IDR_ALL_MASK);
        zynqmp_gqspi_write(xqspi,
                           GQSPI_QSPIDMA_DST_I_DIS_OFST,
                           GQSPI_QSPIDMA_DST_INTR_ALL_MASK);
        /* Disable the GQSPI */
        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
        config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
        config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
        /* Manual start */
        config_reg |= GQSPI_CFG_GEN_FIFO_START_MODE_MASK;
        /* Little endian by default */
        config_reg &= ~GQSPI_CFG_ENDIAN_MASK;
        /* Disable poll time out */
        config_reg &= ~GQSPI_CFG_EN_POLL_TO_MASK;
        /* Set hold bit */
        config_reg |= GQSPI_CFG_WP_HOLD_MASK;
        /* Clear pre-scalar by default */
        config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
        /* Set CPHA */
        if (xqspi->ctlr->mode_bits & SPI_CPHA)
                config_reg |= GQSPI_CFG_CLK_PHA_MASK;
        else
                config_reg &= ~GQSPI_CFG_CLK_PHA_MASK;
        /* Set CPOL */
        if (xqspi->ctlr->mode_bits & SPI_CPOL)
                config_reg |= GQSPI_CFG_CLK_POL_MASK;
        else
                config_reg &= ~GQSPI_CFG_CLK_POL_MASK;

        /* Set the clock frequency */
        clk_rate = clk_get_rate(xqspi->refclk);
        while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) &&
               (clk_rate /
                (GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > xqspi->speed_hz)
                baud_rate_val++;

        config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
        config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT);

        zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);

        /* Set the tapdelay for clock frequency */
        zynqmp_qspi_set_tapdelay(xqspi, baud_rate_val);

        /* Clear the TX and RX FIFO */
        zynqmp_gqspi_write(xqspi, GQSPI_FIFO_CTRL_OFST,
                           GQSPI_FIFO_CTRL_RST_RX_FIFO_MASK |
                           GQSPI_FIFO_CTRL_RST_TX_FIFO_MASK |
                           GQSPI_FIFO_CTRL_RST_GEN_FIFO_MASK);
        /* Reset thresholds */
        zynqmp_gqspi_write(xqspi, GQSPI_TX_THRESHOLD_OFST,
                           GQSPI_TX_FIFO_THRESHOLD_RESET_VAL);
        zynqmp_gqspi_write(xqspi, GQSPI_RX_THRESHOLD_OFST,
                           GQSPI_RX_FIFO_THRESHOLD);
        zynqmp_gqspi_write(xqspi, GQSPI_GF_THRESHOLD_OFST,
                           GQSPI_GEN_FIFO_THRESHOLD_RESET_VAL);
        zynqmp_gqspi_selecttarget(xqspi,
                                  GQSPI_SELECT_FLASH_CS_LOWER,
                                  GQSPI_SELECT_FLASH_BUS_LOWER);
        /* Initialize DMA */
        zynqmp_gqspi_write(xqspi,
                           GQSPI_QSPIDMA_DST_CTRL_OFST,
                           GQSPI_QSPIDMA_DST_CTRL_RESET_VAL);

        /* Enable the GQSPI */
        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
}

/**
 * zynqmp_qspi_copy_read_data - Copy data to RX buffer
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @data:       The variable where data is stored
 * @size:       Number of bytes to be copied from data to RX buffer
 */
static void zynqmp_qspi_copy_read_data(struct zynqmp_qspi *xqspi,
                                       ulong data, u8 size)
{
        memcpy(xqspi->rxbuf, &data, size);
        xqspi->rxbuf += size;
        xqspi->bytes_to_receive -= size;
}

/**
 * zynqmp_qspi_chipselect - Select or deselect the chip select line
 * @qspi:       Pointer to the spi_device structure
 * @is_high:    Select(0) or deselect (1) the chip select line
 */
static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high)
{
        struct zynqmp_qspi *xqspi = spi_controller_get_devdata(qspi->controller);
        ulong timeout;
        u32 genfifoentry = 0, statusreg;

        genfifoentry |= GQSPI_GENFIFO_MODE_SPI;

        if (!is_high) {
                if (!spi_get_chipselect(qspi, 0)) {
                        xqspi->genfifobus = GQSPI_GENFIFO_BUS_LOWER;
                        xqspi->genfifocs = GQSPI_GENFIFO_CS_LOWER;
                } else {
                        xqspi->genfifobus = GQSPI_GENFIFO_BUS_UPPER;
                        xqspi->genfifocs = GQSPI_GENFIFO_CS_UPPER;
                }
                genfifoentry |= xqspi->genfifobus;
                genfifoentry |= xqspi->genfifocs;
                genfifoentry |= GQSPI_GENFIFO_CS_SETUP;
        } else {
                genfifoentry |= GQSPI_GENFIFO_CS_HOLD;
        }

        zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);

        /* Manually start the generic FIFO command */
        zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                           zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
                           GQSPI_CFG_START_GEN_FIFO_MASK);

        timeout = jiffies + msecs_to_jiffies(1000);

        /* Wait until the generic FIFO command is empty */
        do {
                statusreg = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);

                if ((statusreg & GQSPI_ISR_GENFIFOEMPTY_MASK) &&
                    (statusreg & GQSPI_ISR_TXEMPTY_MASK))
                        break;
                cpu_relax();
        } while (!time_after_eq(jiffies, timeout));

        if (time_after_eq(jiffies, timeout))
                dev_err(xqspi->dev, "Chip select timed out\n");
}

/**
 * zynqmp_qspi_selectspimode - Selects SPI mode - x1 or x2 or x4.
 * @xqspi:      xqspi is a pointer to the GQSPI instance
 * @spimode:    spimode - SPI or DUAL or QUAD.
 * Return:      Mask to set desired SPI mode in GENFIFO entry.
 */
static inline u32 zynqmp_qspi_selectspimode(struct zynqmp_qspi *xqspi,
                                            u8 spimode)
{
        u32 mask = 0;

        switch (spimode) {
        case GQSPI_SELECT_MODE_DUALSPI:
                mask = GQSPI_GENFIFO_MODE_DUALSPI;
                break;
        case GQSPI_SELECT_MODE_QUADSPI:
                mask = GQSPI_GENFIFO_MODE_QUADSPI;
                break;
        case GQSPI_SELECT_MODE_SPI:
                mask = GQSPI_GENFIFO_MODE_SPI;
                break;
        default:
                dev_warn(xqspi->dev, "Invalid SPI mode\n");
        }

        return mask;
}

/**
 * zynqmp_qspi_config_op - Configure QSPI controller for specified
 *                              transfer
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @op:         The memory operation to execute
 *
 * Sets the operational mode of QSPI controller for the next QSPI transfer and
 * sets the requested clock frequency.
 *
 * Return:      Always 0
 *
 * Note:
 *      If the requested frequency is not an exact match with what can be
 *      obtained using the pre-scalar value, the driver sets the clock
 *      frequency which is lower than the requested frequency (maximum lower)
 *      for the transfer.
 *
 *      If the requested frequency is higher or lower than that is supported
 *      by the QSPI controller the driver will set the highest or lowest
 *      frequency supported by controller.
 */
static int zynqmp_qspi_config_op(struct zynqmp_qspi *xqspi,
                                 const struct spi_mem_op *op)
{
        ulong clk_rate;
        u32 config_reg, req_speed_hz, baud_rate_val = 0;

        req_speed_hz = op->max_freq;

        if (xqspi->speed_hz != req_speed_hz) {
                xqspi->speed_hz = req_speed_hz;

                /* Set the clock frequency */
                /* If req_speed_hz == 0, default to lowest speed */
                clk_rate = clk_get_rate(xqspi->refclk);

                while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) &&
                       (clk_rate /
                        (GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) >
                       req_speed_hz)
                        baud_rate_val++;

                config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);

                config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
                config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT);
                zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
                zynqmp_qspi_set_tapdelay(xqspi, baud_rate_val);
        }

        dev_dbg(xqspi->dev, "config speed %u\n", req_speed_hz);
        return 0;
}

/**
 * zynqmp_qspi_setup_op - Configure the QSPI controller
 * @qspi:       Pointer to the spi_device structure
 *
 * Sets the operational mode of QSPI controller for the next QSPI transfer,
 * baud rate and divisor value to setup the requested qspi clock.
 *
 * Return:      0 on success; error value otherwise.
 */
static int zynqmp_qspi_setup_op(struct spi_device *qspi)
{
        struct spi_controller *ctlr = qspi->controller;
        struct zynqmp_qspi *xqspi = spi_controller_get_devdata(ctlr);

        if (ctlr->busy)
                return -EBUSY;

        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);

        return 0;
}

/**
 * zynqmp_qspi_filltxfifo - Fills the TX FIFO as long as there is room in
 *                              the FIFO or the bytes required to be
 *                              transmitted.
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @size:       Number of bytes to be copied from TX buffer to TX FIFO
 */
static void zynqmp_qspi_filltxfifo(struct zynqmp_qspi *xqspi, int size)
{
        u32 count = 0, intermediate;

        while ((xqspi->bytes_to_transfer > 0) && (count < size) && (xqspi->txbuf)) {
                if (xqspi->bytes_to_transfer >= 4) {
                        memcpy(&intermediate, xqspi->txbuf, 4);
                        xqspi->txbuf += 4;
                        xqspi->bytes_to_transfer -= 4;
                        count += 4;
                } else {
                        memcpy(&intermediate, xqspi->txbuf,
                               xqspi->bytes_to_transfer);
                        xqspi->txbuf += xqspi->bytes_to_transfer;
                        xqspi->bytes_to_transfer = 0;
                        count += xqspi->bytes_to_transfer;
                }
                zynqmp_gqspi_write(xqspi, GQSPI_TXD_OFST, intermediate);
        }
}

/**
 * zynqmp_qspi_readrxfifo - Fills the RX FIFO as long as there is room in
 *                              the FIFO.
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @size:       Number of bytes to be copied from RX buffer to RX FIFO
 */
static void zynqmp_qspi_readrxfifo(struct zynqmp_qspi *xqspi, u32 size)
{
        ulong data;
        int count = 0;

        while ((count < size) && (xqspi->bytes_to_receive > 0)) {
                if (xqspi->bytes_to_receive >= 4) {
                        (*(u32 *)xqspi->rxbuf) =
                        zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
                        xqspi->rxbuf += 4;
                        xqspi->bytes_to_receive -= 4;
                        count += 4;
                } else {
                        data = zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
                        count += xqspi->bytes_to_receive;
                        zynqmp_qspi_copy_read_data(xqspi, data,
                                                   xqspi->bytes_to_receive);
                        xqspi->bytes_to_receive = 0;
                }
        }
}

/**
 * zynqmp_qspi_fillgenfifo - Fills the GENFIFO.
 * @xqspi:      Pointer to the zynqmp_qspi structure
 * @nbits:      Transfer/Receive buswidth.
 * @genfifoentry:       Variable in which GENFIFO mask is saved
 */
static void zynqmp_qspi_fillgenfifo(struct zynqmp_qspi *xqspi, u8 nbits,
                                    u32 genfifoentry)
{
        u32 transfer_len, tempcount, exponent;
        u8 imm_data;

        genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
        if (xqspi->rxbuf) {
                genfifoentry |= GQSPI_GENFIFO_RX;
                if (xqspi->mode == GQSPI_MODE_DMA)
                        transfer_len = xqspi->dma_rx_bytes;
                else
                        transfer_len = xqspi->bytes_to_receive;
        } else {
                transfer_len = xqspi->bytes_to_transfer;
        }

        if (xqspi->txbuf)
                genfifoentry |= GQSPI_GENFIFO_TX;

        genfifoentry |= zynqmp_qspi_selectspimode(xqspi, nbits);
        xqspi->genfifoentry = genfifoentry;
        dev_dbg(xqspi->dev, "genfifo %05x transfer_len %u\n",
                genfifoentry, transfer_len);

        /* Exponent entries */
        imm_data = transfer_len;
        tempcount = transfer_len >> 8;
        exponent = 8;
        genfifoentry |= GQSPI_GENFIFO_EXP;
        while (tempcount) {
                if (tempcount & 1)
                        zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST,
                                           genfifoentry | exponent);
                tempcount >>= 1;
                exponent++;
        }

        /* Immediate entry */
        genfifoentry &= ~GQSPI_GENFIFO_EXP;
        if (imm_data)
                zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST,
                                   genfifoentry | imm_data);

        /* Dummy generic FIFO entry */
        if (xqspi->mode == GQSPI_MODE_IO && xqspi->rxbuf)
                zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0);
}

/**
 * zynqmp_qspi_disable_dma() - Disable DMA mode
 * @xqspi: GQSPI instance
 */
static void zynqmp_qspi_disable_dma(struct zynqmp_qspi *xqspi)
{
        u32 config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);

        config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
        zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
        xqspi->mode = GQSPI_MODE_IO;
}

/**
 * zynqmp_qspi_enable_dma() - Enable DMA mode
 * @xqspi: GQSPI instance
 */
static void zynqmp_qspi_enable_dma(struct zynqmp_qspi *xqspi)
{
        u32 config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);

        config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
        config_reg |= GQSPI_CFG_MODE_EN_DMA_MASK;
        zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
        xqspi->mode = GQSPI_MODE_DMA;
}

/**
 * zynqmp_process_dma_irq - Handler for DMA done interrupt of QSPI
 *                              controller
 * @xqspi:      zynqmp_qspi instance pointer
 *
 * This function handles DMA interrupt only.
 */
static void zynqmp_process_dma_irq(struct zynqmp_qspi *xqspi)
{
        u32 genfifoentry;

        dma_unmap_single(xqspi->dev, xqspi->dma_addr,
                         xqspi->dma_rx_bytes, DMA_FROM_DEVICE);
        xqspi->rxbuf += xqspi->dma_rx_bytes;
        xqspi->bytes_to_receive -= xqspi->dma_rx_bytes;
        xqspi->dma_rx_bytes = 0;

        /* Disabling the DMA interrupts */
        zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_DIS_OFST,
                           GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);

        if (xqspi->bytes_to_receive > 0) {
                /* Switch to IO mode,for remaining bytes to receive */
                zynqmp_qspi_disable_dma(xqspi);

                /* Initiate the transfer of remaining bytes */
                genfifoentry = xqspi->genfifoentry;
                genfifoentry |= xqspi->bytes_to_receive;
                zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);

                /* Dummy generic FIFO entry */
                zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);

                /* Manual start */
                zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                                   (zynqmp_gqspi_read(xqspi,
                                                      GQSPI_CONFIG_OFST) |
                                   GQSPI_CFG_START_GEN_FIFO_MASK));

                /* Enable the RX interrupts for IO mode */
                zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
                                   GQSPI_IER_GENFIFOEMPTY_MASK |
                                   GQSPI_IER_RXNEMPTY_MASK |
                                   GQSPI_IER_RXEMPTY_MASK);
        }
}

/**
 * zynqmp_qspi_irq - Interrupt service routine of the QSPI controller
 * @irq:        IRQ number
 * @dev_id:     Pointer to the xqspi structure
 *
 * This function handles TX empty only.
 * On TX empty interrupt this function reads the received data from RX FIFO
 * and fills the TX FIFO if there is any data remaining to be transferred.
 *
 * Return:      IRQ_HANDLED when interrupt is handled
 *              IRQ_NONE otherwise.
 */
static irqreturn_t zynqmp_qspi_irq(int irq, void *dev_id)
{
        struct zynqmp_qspi *xqspi = (struct zynqmp_qspi *)dev_id;
        u32 status, mask, dma_status = 0;

        status = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
        zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST, status);
        mask = (status & ~(zynqmp_gqspi_read(xqspi, GQSPI_IMASK_OFST)));

        /* Read and clear DMA status */
        if (xqspi->mode == GQSPI_MODE_DMA) {
                dma_status =
                        zynqmp_gqspi_read(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST);
                zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
                                   dma_status);
        }

        if (!mask && !dma_status)
                return IRQ_NONE;

        if (mask & GQSPI_ISR_TXNOT_FULL_MASK)
                zynqmp_qspi_filltxfifo(xqspi, GQSPI_TX_FIFO_FILL);

        if (dma_status & GQSPI_QSPIDMA_DST_I_STS_DONE_MASK)
                zynqmp_process_dma_irq(xqspi);
        else if (!(mask & GQSPI_IER_RXEMPTY_MASK) &&
                        (mask & GQSPI_IER_GENFIFOEMPTY_MASK))
                zynqmp_qspi_readrxfifo(xqspi, GQSPI_RX_FIFO_FILL);

        if (xqspi->bytes_to_receive == 0 && xqspi->bytes_to_transfer == 0 &&
            ((status & GQSPI_IRQ_MASK) == GQSPI_IRQ_MASK)) {
                zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_ISR_IDR_MASK);
                complete(&xqspi->data_completion);
        }
        return IRQ_HANDLED;
}

/**
 * zynqmp_qspi_setuprxdma - This function sets up the RX DMA operation
 * @xqspi:      xqspi is a pointer to the GQSPI instance.
 *
 * Return:      0 on success; error value otherwise.
 */
static int zynqmp_qspi_setuprxdma(struct zynqmp_qspi *xqspi)
{
        u32 rx_bytes, rx_rem;
        dma_addr_t addr;
        u64 dma_align =  (u64)(uintptr_t)xqspi->rxbuf;

        if (xqspi->bytes_to_receive < 8 ||
            ((dma_align & GQSPI_DMA_UNALIGN) != 0x0)) {
                /* Setting to IO mode */
                zynqmp_qspi_disable_dma(xqspi);
                xqspi->dma_rx_bytes = 0;
                return 0;
        }

        rx_rem = xqspi->bytes_to_receive % 4;
        rx_bytes = (xqspi->bytes_to_receive - rx_rem);

        addr = dma_map_single(xqspi->dev, (void *)xqspi->rxbuf,
                              rx_bytes, DMA_FROM_DEVICE);
        if (dma_mapping_error(xqspi->dev, addr)) {
                dev_err(xqspi->dev, "ERR:rxdma:memory not mapped\n");
                return -ENOMEM;
        }

        xqspi->dma_rx_bytes = rx_bytes;
        xqspi->dma_addr = addr;
        zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_OFST,
                           (u32)(addr & 0xffffffff));
        addr = ((addr >> 16) >> 16);
        zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_MSB_OFST,
                           ((u32)addr) & 0xfff);

        zynqmp_qspi_enable_dma(xqspi);

        /* Write the number of bytes to transfer */
        zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_SIZE_OFST, rx_bytes);

        return 0;
}

/**
 * zynqmp_qspi_write_op - This function sets up the GENFIFO entries,
 *                      TX FIFO, and fills the TX FIFO with as many
 *                      bytes as possible.
 * @xqspi:      Pointer to the GQSPI instance.
 * @tx_nbits:   Transfer buswidth.
 * @genfifoentry:       Variable in which GENFIFO mask is returned
 *                      to calling function
 */
static void zynqmp_qspi_write_op(struct zynqmp_qspi *xqspi, u8 tx_nbits,
                                 u32 genfifoentry)
{
        zynqmp_qspi_fillgenfifo(xqspi, tx_nbits, genfifoentry);
        zynqmp_qspi_filltxfifo(xqspi, GQSPI_TXD_DEPTH);
        if (xqspi->mode == GQSPI_MODE_DMA)
                zynqmp_qspi_disable_dma(xqspi);
}

/**
 * zynqmp_qspi_read_op - This function sets up the GENFIFO entries and
 *                              RX DMA operation.
 * @xqspi:      xqspi is a pointer to the GQSPI instance.
 * @rx_nbits:   Receive buswidth.
 * @genfifoentry:       genfifoentry is pointer to the variable in which
 *                      GENFIFO mask is returned to calling function
 *
 * Return:      0 on success; error value otherwise.
 */
static int zynqmp_qspi_read_op(struct zynqmp_qspi *xqspi, u8 rx_nbits,
                                u32 genfifoentry)
{
        int ret;

        ret = zynqmp_qspi_setuprxdma(xqspi);
        if (ret)
                return ret;
        zynqmp_qspi_fillgenfifo(xqspi, rx_nbits, genfifoentry);

        return 0;
}

/**
 * zynqmp_qspi_suspend - Suspend method for the QSPI driver
 * @dev:        Address of the platform_device structure
 *
 * This function stops the QSPI driver queue and disables the QSPI controller
 *
 * Return:      Always 0
 */
static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
{
        struct zynqmp_qspi *xqspi = dev_get_drvdata(dev);
        struct spi_controller *ctlr = xqspi->ctlr;
        int ret;

        ret = spi_controller_suspend(ctlr);
        if (ret)
                return ret;

        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);

        return 0;
}

/**
 * zynqmp_qspi_resume - Resume method for the QSPI driver
 * @dev:        Address of the platform_device structure
 *
 * The function starts the QSPI driver queue and initializes the QSPI
 * controller
 *
 * Return:      0 on success; error value otherwise
 */
static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
{
        struct zynqmp_qspi *xqspi = dev_get_drvdata(dev);
        struct spi_controller *ctlr = xqspi->ctlr;

        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);

        spi_controller_resume(ctlr);

        return 0;
}

/**
 * zynqmp_runtime_suspend - Runtime suspend method for the SPI driver
 * @dev:        Address of the platform_device structure
 *
 * This function disables the clocks
 *
 * Return:      Always 0
 */
static int __maybe_unused zynqmp_runtime_suspend(struct device *dev)
{
        struct zynqmp_qspi *xqspi = dev_get_drvdata(dev);

        clk_disable_unprepare(xqspi->refclk);
        clk_disable_unprepare(xqspi->pclk);

        return 0;
}

/**
 * zynqmp_runtime_resume - Runtime resume method for the SPI driver
 * @dev:        Address of the platform_device structure
 *
 * This function enables the clocks
 *
 * Return:      0 on success and error value on error
 */
static int __maybe_unused zynqmp_runtime_resume(struct device *dev)
{
        struct zynqmp_qspi *xqspi = dev_get_drvdata(dev);
        int ret;

        ret = clk_prepare_enable(xqspi->pclk);
        if (ret) {
                dev_err(dev, "Cannot enable APB clock.\n");
                return ret;
        }

        ret = clk_prepare_enable(xqspi->refclk);
        if (ret) {
                dev_err(dev, "Cannot enable device clock.\n");
                clk_disable_unprepare(xqspi->pclk);
                return ret;
        }

        return 0;
}

static unsigned long zynqmp_qspi_timeout(struct zynqmp_qspi *xqspi, u8 bits,
                                         unsigned long bytes)
{
        unsigned long timeout;

        /* Assume we are at most 2x slower than the nominal bus speed */
        timeout = mult_frac(bytes, 2 * 8 * MSEC_PER_SEC,
                            bits * xqspi->speed_hz);
        /* And add 100 ms for scheduling delays */
        return msecs_to_jiffies(timeout + 100);
}

/**
 * zynqmp_qspi_exec_op() - Initiates the QSPI transfer
 * @mem: The SPI memory
 * @op: The memory operation to execute
 *
 * Executes a memory operation.
 *
 * This function first selects the chip and starts the memory operation.
 *
 * Return: 0 in case of success, a negative error code otherwise.
 */
static int zynqmp_qspi_exec_op(struct spi_mem *mem,
                               const struct spi_mem_op *op)
{
        struct zynqmp_qspi *xqspi =
                spi_controller_get_devdata(mem->spi->controller);
        unsigned long timeout;
        int err = 0, i;
        u32 genfifoentry = 0;
        u16 opcode = op->cmd.opcode;
        u64 opaddr;

        mutex_lock(&xqspi->op_lock);
        zynqmp_qspi_config_op(xqspi, op);
        zynqmp_qspi_chipselect(mem->spi, false);
        genfifoentry |= xqspi->genfifocs;
        genfifoentry |= xqspi->genfifobus;

        if (op->cmd.opcode) {
                reinit_completion(&xqspi->data_completion);
                xqspi->txbuf = &opcode;
                xqspi->rxbuf = NULL;
                xqspi->bytes_to_transfer = op->cmd.nbytes;
                xqspi->bytes_to_receive = 0;
                zynqmp_qspi_write_op(xqspi, op->cmd.buswidth, genfifoentry);
                zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                                   zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
                                   GQSPI_CFG_START_GEN_FIFO_MASK);
                zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
                                   GQSPI_IER_GENFIFOEMPTY_MASK |
                                   GQSPI_IER_TXNOT_FULL_MASK);
                timeout = zynqmp_qspi_timeout(xqspi, op->cmd.buswidth,
                                              op->cmd.nbytes);
                if (!wait_for_completion_timeout(&xqspi->data_completion,
                                                 timeout)) {
                        err = -ETIMEDOUT;
                        goto return_err;
                }
        }

        if (op->addr.nbytes) {
                xqspi->txbuf = &opaddr;
                for (i = 0; i < op->addr.nbytes; i++) {
                        *(((u8 *)xqspi->txbuf) + i) = op->addr.val >>
                                        (8 * (op->addr.nbytes - i - 1));
                }

                reinit_completion(&xqspi->data_completion);
                xqspi->rxbuf = NULL;
                xqspi->bytes_to_transfer = op->addr.nbytes;
                xqspi->bytes_to_receive = 0;
                zynqmp_qspi_write_op(xqspi, op->addr.buswidth, genfifoentry);
                zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                                   zynqmp_gqspi_read(xqspi,
                                                     GQSPI_CONFIG_OFST) |
                                   GQSPI_CFG_START_GEN_FIFO_MASK);
                zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
                                   GQSPI_IER_TXEMPTY_MASK |
                                   GQSPI_IER_GENFIFOEMPTY_MASK |
                                   GQSPI_IER_TXNOT_FULL_MASK);
                timeout = zynqmp_qspi_timeout(xqspi, op->addr.buswidth,
                                              op->addr.nbytes);
                if (!wait_for_completion_timeout(&xqspi->data_completion,
                                                 timeout)) {
                        err = -ETIMEDOUT;
                        goto return_err;
                }
        }

        if (op->dummy.nbytes) {
                xqspi->txbuf = NULL;
                xqspi->rxbuf = NULL;
                /*
                 * xqspi->bytes_to_transfer here represents the dummy circles
                 * which need to be sent.
                 */
                xqspi->bytes_to_transfer = op->dummy.nbytes * 8 / op->dummy.buswidth;
                xqspi->bytes_to_receive = 0;
                /*
                 * Using op->data.buswidth instead of op->dummy.buswidth here because
                 * we need to use it to configure the correct SPI mode.
                 */
                zynqmp_qspi_write_op(xqspi, op->data.buswidth,
                                     genfifoentry);
                zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                                   zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
                                   GQSPI_CFG_START_GEN_FIFO_MASK);
        }

        if (op->data.nbytes) {
                reinit_completion(&xqspi->data_completion);
                if (op->data.dir == SPI_MEM_DATA_OUT) {
                        xqspi->txbuf = (u8 *)op->data.buf.out;
                        xqspi->rxbuf = NULL;
                        xqspi->bytes_to_transfer = op->data.nbytes;
                        xqspi->bytes_to_receive = 0;
                        zynqmp_qspi_write_op(xqspi, op->data.buswidth,
                                             genfifoentry);
                        zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                                           zynqmp_gqspi_read
                                           (xqspi, GQSPI_CONFIG_OFST) |
                                           GQSPI_CFG_START_GEN_FIFO_MASK);
                        zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
                                           GQSPI_IER_TXEMPTY_MASK |
                                           GQSPI_IER_GENFIFOEMPTY_MASK |
                                           GQSPI_IER_TXNOT_FULL_MASK);
                } else {
                        xqspi->txbuf = NULL;
                        xqspi->rxbuf = (u8 *)op->data.buf.in;
                        xqspi->bytes_to_receive = op->data.nbytes;
                        xqspi->bytes_to_transfer = 0;
                        err = zynqmp_qspi_read_op(xqspi, op->data.buswidth,
                                            genfifoentry);
                        if (err)
                                goto return_err;

                        zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
                                           zynqmp_gqspi_read
                                           (xqspi, GQSPI_CONFIG_OFST) |
                                           GQSPI_CFG_START_GEN_FIFO_MASK);
                        if (xqspi->mode == GQSPI_MODE_DMA) {
                                zynqmp_gqspi_write
                                        (xqspi, GQSPI_QSPIDMA_DST_I_EN_OFST,
                                         GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
                        } else {
                                zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
                                                   GQSPI_IER_GENFIFOEMPTY_MASK |
                                                   GQSPI_IER_RXNEMPTY_MASK |
                                                   GQSPI_IER_RXEMPTY_MASK);
                        }
                }
                timeout = zynqmp_qspi_timeout(xqspi, op->data.buswidth,
                                              op->data.nbytes);
                if (!wait_for_completion_timeout(&xqspi->data_completion, timeout))
                        err = -ETIMEDOUT;
        }

return_err:

        zynqmp_qspi_chipselect(mem->spi, true);
        mutex_unlock(&xqspi->op_lock);

        return err;
}

static const struct dev_pm_ops zynqmp_qspi_dev_pm_ops = {
        SET_RUNTIME_PM_OPS(zynqmp_runtime_suspend,
                           zynqmp_runtime_resume, NULL)
        SET_SYSTEM_SLEEP_PM_OPS(zynqmp_qspi_suspend, zynqmp_qspi_resume)
};

static const struct qspi_platform_data versal_qspi_def = {
        .quirks = QSPI_QUIRK_HAS_TAPDELAY,
};

static const struct of_device_id zynqmp_qspi_of_match[] = {
        { .compatible = "xlnx,zynqmp-qspi-1.0"},
        { .compatible = "xlnx,versal-qspi-1.0", .data = &versal_qspi_def },
        { /* End of table */ }
};

static const struct spi_controller_mem_ops zynqmp_qspi_mem_ops = {
        .exec_op = zynqmp_qspi_exec_op,
};

static const struct spi_controller_mem_caps zynqmp_qspi_mem_caps = {
        .per_op_freq = true,
};

/**
 * zynqmp_qspi_probe - Probe method for the QSPI driver
 * @pdev:       Pointer to the platform_device structure
 *
 * This function initializes the driver data structures and the hardware.
 *
 * Return:      0 on success; error value otherwise
 */
static int zynqmp_qspi_probe(struct platform_device *pdev)
{
        int ret = 0;
        struct spi_controller *ctlr;
        struct zynqmp_qspi *xqspi;
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        u32 num_cs;
        const struct qspi_platform_data *p_data;

        ctlr = devm_spi_alloc_host(&pdev->dev, sizeof(*xqspi));
        if (!ctlr)
                return -ENOMEM;

        xqspi = spi_controller_get_devdata(ctlr);
        xqspi->dev = dev;
        xqspi->ctlr = ctlr;
        platform_set_drvdata(pdev, xqspi);

        p_data = of_device_get_match_data(&pdev->dev);
        if (p_data && (p_data->quirks & QSPI_QUIRK_HAS_TAPDELAY))
                xqspi->has_tapdelay = true;

        xqspi->regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(xqspi->regs))
                return PTR_ERR(xqspi->regs);

        xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
        if (IS_ERR(xqspi->pclk))
                return dev_err_probe(dev, PTR_ERR(xqspi->pclk),
                                     "pclk clock not found.\n");

        xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
        if (IS_ERR(xqspi->refclk))
                return dev_err_probe(dev, PTR_ERR(xqspi->refclk),
                                     "ref_clk clock not found.\n");

        ret = clk_prepare_enable(xqspi->pclk);
        if (ret)
                return dev_err_probe(dev, ret, "Unable to enable APB clock.\n");

        ret = clk_prepare_enable(xqspi->refclk);
        if (ret) {
                dev_err(dev, "Unable to enable device clock.\n");
                goto clk_dis_pclk;
        }

        init_completion(&xqspi->data_completion);

        mutex_init(&xqspi->op_lock);

        pm_runtime_use_autosuspend(&pdev->dev);
        pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
        pm_runtime_set_active(&pdev->dev);
        pm_runtime_enable(&pdev->dev);

        ret = pm_runtime_get_sync(&pdev->dev);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to pm_runtime_get_sync: %d\n", ret);
                goto clk_dis_all;
        }

        ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
                SPI_TX_DUAL | SPI_TX_QUAD;
        ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
        xqspi->speed_hz = ctlr->max_speed_hz;

        /* QSPI controller initializations */
        zynqmp_qspi_init_hw(xqspi);

        xqspi->irq = platform_get_irq(pdev, 0);
        if (xqspi->irq < 0) {
                ret = xqspi->irq;
                goto clk_dis_all;
        }
        ret = devm_request_irq(&pdev->dev, xqspi->irq, zynqmp_qspi_irq,
                               0, pdev->name, xqspi);
        if (ret != 0) {
                ret = -ENXIO;
                dev_err(dev, "request_irq failed\n");
                goto clk_dis_all;
        }

        ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
        if (ret)
                goto clk_dis_all;

        ret = of_property_read_u32(np, "num-cs", &num_cs);
        if (ret < 0) {
                ctlr->num_chipselect = GQSPI_DEFAULT_NUM_CS;
        } else if (num_cs > GQSPI_MAX_NUM_CS) {
                ret = -EINVAL;
                dev_err(&pdev->dev, "only %d chip selects are available\n",
                        GQSPI_MAX_NUM_CS);
                goto clk_dis_all;
        } else {
                ctlr->num_chipselect = num_cs;
        }

        ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
        ctlr->mem_ops = &zynqmp_qspi_mem_ops;
        ctlr->mem_caps = &zynqmp_qspi_mem_caps;
        ctlr->setup = zynqmp_qspi_setup_op;
        ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
        ctlr->dev.of_node = np;
        ctlr->auto_runtime_pm = true;

        ret = devm_spi_register_controller(&pdev->dev, ctlr);
        if (ret) {
                dev_err(&pdev->dev, "spi_register_controller failed\n");
                goto clk_dis_all;
        }

        pm_runtime_put_autosuspend(&pdev->dev);

        return 0;

clk_dis_all:
        pm_runtime_disable(&pdev->dev);
        pm_runtime_dont_use_autosuspend(&pdev->dev);
        pm_runtime_put_noidle(&pdev->dev);
        pm_runtime_set_suspended(&pdev->dev);
        clk_disable_unprepare(xqspi->refclk);
clk_dis_pclk:
        clk_disable_unprepare(xqspi->pclk);

        return ret;
}

/**
 * zynqmp_qspi_remove - Remove method for the QSPI driver
 * @pdev:       Pointer to the platform_device structure
 *
 * This function is called if a device is physically removed from the system or
 * if the driver module is being unloaded. It frees all resources allocated to
 * the device.
 *
 * Return:      0 Always
 */
static void zynqmp_qspi_remove(struct platform_device *pdev)
{
        struct zynqmp_qspi *xqspi = platform_get_drvdata(pdev);

        pm_runtime_get_sync(&pdev->dev);

        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);

        pm_runtime_disable(&pdev->dev);
        pm_runtime_dont_use_autosuspend(&pdev->dev);
        pm_runtime_put_noidle(&pdev->dev);
        pm_runtime_set_suspended(&pdev->dev);
        clk_disable_unprepare(xqspi->refclk);
        clk_disable_unprepare(xqspi->pclk);
}

MODULE_DEVICE_TABLE(of, zynqmp_qspi_of_match);

static struct platform_driver zynqmp_qspi_driver = {
        .probe = zynqmp_qspi_probe,
        .remove = zynqmp_qspi_remove,
        .driver = {
                .name = "zynqmp-qspi",
                .of_match_table = zynqmp_qspi_of_match,
                .pm = &zynqmp_qspi_dev_pm_ops,
        },
};

module_platform_driver(zynqmp_qspi_driver);

MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx Zynqmp QSPI driver");
MODULE_LICENSE("GPL");