/*
 * Copyright 2013-2015 Freescale Semiconductor, Inc.
 *
 * Freescale Quad Serial Peripheral Interface (QSPI) driver
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
#include <linux/sizes.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include "fsl_qspi.h"

DECLARE_GLOBAL_DATA_PTR;

#define RX_BUFFER_SIZE          0x80
#ifdef CONFIG_MX6SX
#define TX_BUFFER_SIZE          0x200
#else
#define TX_BUFFER_SIZE          0x40
#endif

#define OFFSET_BITS_MASK        GENMASK(23, 0)

#define FLASH_STATUS_WEL        0x02

/* SEQID */
#define SEQID_WREN              1
#define SEQID_FAST_READ         2
#define SEQID_RDSR              3
#define SEQID_SE                4
#define SEQID_CHIP_ERASE        5
#define SEQID_PP                6
#define SEQID_RDID              7
#define SEQID_BE_4K             8
#ifdef CONFIG_SPI_FLASH_BAR
#define SEQID_BRRD              9
#define SEQID_BRWR              10
#define SEQID_RDEAR             11
#define SEQID_WREAR             12
#endif

/* QSPI CMD */
#define QSPI_CMD_PP             0x02    /* Page program (up to 256 bytes) */
#define QSPI_CMD_RDSR           0x05    /* Read status register */
#define QSPI_CMD_WREN           0x06    /* Write enable */
#define QSPI_CMD_FAST_READ      0x0b    /* Read data bytes (high frequency) */
#define QSPI_CMD_BE_4K          0x20    /* 4K erase */
#define QSPI_CMD_CHIP_ERASE     0xc7    /* Erase whole flash chip */
#define QSPI_CMD_SE             0xd8    /* Sector erase (usually 64KiB) */
#define QSPI_CMD_RDID           0x9f    /* Read JEDEC ID */

/* Used for Micron, winbond and Macronix flashes */
#define QSPI_CMD_WREAR          0xc5    /* EAR register write */
#define QSPI_CMD_RDEAR          0xc8    /* EAR reigster read */

/* Used for Spansion flashes only. */
#define QSPI_CMD_BRRD           0x16    /* Bank register read */
#define QSPI_CMD_BRWR           0x17    /* Bank register write */

/* 4-byte address QSPI CMD - used on Spansion and some Macronix flashes */
#define QSPI_CMD_FAST_READ_4B   0x0c    /* Read data bytes (high frequency) */
#define QSPI_CMD_PP_4B          0x12    /* Page program (up to 256 bytes) */
#define QSPI_CMD_SE_4B          0xdc    /* Sector erase (usually 64KiB) */

/* fsl_qspi_platdata flags */
#define QSPI_FLAG_REGMAP_ENDIAN_BIG     BIT(0)

/* default SCK frequency, unit: HZ */
#define FSL_QSPI_DEFAULT_SCK_FREQ       50000000

/* QSPI max chipselect signals number */
#define FSL_QSPI_MAX_CHIPSELECT_NUM     4

#ifdef CONFIG_DM_SPI
/**
 * struct fsl_qspi_platdata - platform data for Freescale QSPI
 *
 * @flags: Flags for QSPI QSPI_FLAG_...
 * @speed_hz: Default SCK frequency
 * @reg_base: Base address of QSPI registers
 * @amba_base: Base address of QSPI memory mapping
 * @amba_total_size: size of QSPI memory mapping
 * @flash_num: Number of active slave devices
 * @num_chipselect: Number of QSPI chipselect signals
 */
struct fsl_qspi_platdata {
        u32 flags;
        u32 speed_hz;
        u32 reg_base;
        u32 amba_base;
        u32 amba_total_size;
        u32 flash_num;
        u32 num_chipselect;
};
#endif

/**
 * struct fsl_qspi_priv - private data for Freescale QSPI
 *
 * @flags: Flags for QSPI QSPI_FLAG_...
 * @bus_clk: QSPI input clk frequency
 * @speed_hz: Default SCK frequency
 * @cur_seqid: current LUT table sequence id
 * @sf_addr: flash access offset
 * @amba_base: Base address of QSPI memory mapping of every CS
 * @amba_total_size: size of QSPI memory mapping
 * @cur_amba_base: Base address of QSPI memory mapping of current CS
 * @flash_num: Number of active slave devices
 * @num_chipselect: Number of QSPI chipselect signals
 * @regs: Point to QSPI register structure for I/O access
 */
struct fsl_qspi_priv {
        u32 flags;
        u32 bus_clk;
        u32 speed_hz;
        u32 cur_seqid;
        u32 sf_addr;
        u32 amba_base[FSL_QSPI_MAX_CHIPSELECT_NUM];
        u32 amba_total_size;
        u32 cur_amba_base;
        u32 flash_num;
        u32 num_chipselect;
        struct fsl_qspi_regs *regs;
};

#ifndef CONFIG_DM_SPI
struct fsl_qspi {
        struct spi_slave slave;
        struct fsl_qspi_priv priv;
};
#endif

static u32 qspi_read32(u32 flags, u32 *addr)
{
        return flags & QSPI_FLAG_REGMAP_ENDIAN_BIG ?
                in_be32(addr) : in_le32(addr);
}

static void qspi_write32(u32 flags, u32 *addr, u32 val)
{
        flags & QSPI_FLAG_REGMAP_ENDIAN_BIG ?
                out_be32(addr, val) : out_le32(addr, val);
}

/* QSPI support swapping the flash read/write data
 * in hardware for LS102xA, but not for VF610 */
static inline u32 qspi_endian_xchg(u32 data)
{
#ifdef CONFIG_VF610
        return swab32(data);
#else
        return data;
#endif
}

static void qspi_set_lut(struct fsl_qspi_priv *priv)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 lut_base;

        /* Unlock the LUT */
        qspi_write32(priv->flags, &regs->lutkey, LUT_KEY_VALUE);
        qspi_write32(priv->flags, &regs->lckcr, QSPI_LCKCR_UNLOCK);

        /* Write Enable */
        lut_base = SEQID_WREN * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_WREN) |
                PAD0(LUT_PAD1) | INSTR0(LUT_CMD));
        qspi_write32(priv->flags, &regs->lut[lut_base + 1], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* Fast Read */
        lut_base = SEQID_FAST_READ * 4;
#ifdef CONFIG_SPI_FLASH_BAR
        qspi_write32(priv->flags, &regs->lut[lut_base],
                     OPRND0(QSPI_CMD_FAST_READ) | PAD0(LUT_PAD1) |
                     INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
#else
        if (FSL_QSPI_FLASH_SIZE  <= SZ_16M)
                qspi_write32(priv->flags, &regs->lut[lut_base],
                             OPRND0(QSPI_CMD_FAST_READ) | PAD0(LUT_PAD1) |
                             INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                             PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
        else
                qspi_write32(priv->flags, &regs->lut[lut_base],
                             OPRND0(QSPI_CMD_FAST_READ_4B) |
                             PAD0(LUT_PAD1) | INSTR0(LUT_CMD) |
                             OPRND1(ADDR32BIT) | PAD1(LUT_PAD1) |
                             INSTR1(LUT_ADDR));
#endif
        qspi_write32(priv->flags, &regs->lut[lut_base + 1],
                     OPRND0(8) | PAD0(LUT_PAD1) | INSTR0(LUT_DUMMY) |
                     OPRND1(RX_BUFFER_SIZE) | PAD1(LUT_PAD1) |
                     INSTR1(LUT_READ));
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* Read Status */
        lut_base = SEQID_RDSR * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_RDSR) |
                PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(1) |
                PAD1(LUT_PAD1) | INSTR1(LUT_READ));
        qspi_write32(priv->flags, &regs->lut[lut_base + 1], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* Erase a sector */
        lut_base = SEQID_SE * 4;
#ifdef CONFIG_SPI_FLASH_BAR
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_SE) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
#else
        if (FSL_QSPI_FLASH_SIZE  <= SZ_16M)
                qspi_write32(priv->flags, &regs->lut[lut_base],
                             OPRND0(QSPI_CMD_SE) | PAD0(LUT_PAD1) |
                             INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                             PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
        else
                qspi_write32(priv->flags, &regs->lut[lut_base],
                             OPRND0(QSPI_CMD_SE_4B) | PAD0(LUT_PAD1) |
                             INSTR0(LUT_CMD) | OPRND1(ADDR32BIT) |
                             PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
#endif
        qspi_write32(priv->flags, &regs->lut[lut_base + 1], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* Erase the whole chip */
        lut_base = SEQID_CHIP_ERASE * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base],
                     OPRND0(QSPI_CMD_CHIP_ERASE) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD));
        qspi_write32(priv->flags, &regs->lut[lut_base + 1], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* Page Program */
        lut_base = SEQID_PP * 4;
#ifdef CONFIG_SPI_FLASH_BAR
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_PP) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
#else
        if (FSL_QSPI_FLASH_SIZE  <= SZ_16M)
                qspi_write32(priv->flags, &regs->lut[lut_base],
                             OPRND0(QSPI_CMD_PP) | PAD0(LUT_PAD1) |
                             INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                             PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
        else
                qspi_write32(priv->flags, &regs->lut[lut_base],
                             OPRND0(QSPI_CMD_PP_4B) | PAD0(LUT_PAD1) |
                             INSTR0(LUT_CMD) | OPRND1(ADDR32BIT) |
                             PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));
#endif
#ifdef CONFIG_MX6SX
        /*
         * To MX6SX, OPRND0(TX_BUFFER_SIZE) can not work correctly.
         * So, Use IDATSZ in IPCR to determine the size and here set 0.
         */
        qspi_write32(priv->flags, &regs->lut[lut_base + 1], OPRND0(0) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_WRITE));
#else
        qspi_write32(priv->flags, &regs->lut[lut_base + 1],
                     OPRND0(TX_BUFFER_SIZE) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_WRITE));
#endif
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* READ ID */
        lut_base = SEQID_RDID * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_RDID) |
                PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(8) |
                PAD1(LUT_PAD1) | INSTR1(LUT_READ));
        qspi_write32(priv->flags, &regs->lut[lut_base + 1], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 2], 0);
        qspi_write32(priv->flags, &regs->lut[lut_base + 3], 0);

        /* SUB SECTOR 4K ERASE */
        lut_base = SEQID_BE_4K * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_BE_4K) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(ADDR24BIT) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_ADDR));

#ifdef CONFIG_SPI_FLASH_BAR
        /*
         * BRRD BRWR RDEAR WREAR are all supported, because it is hard to
         * dynamically check whether to set BRRD BRWR or RDEAR WREAR during
         * initialization.
         */
        lut_base = SEQID_BRRD * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_BRRD) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(1) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_READ));

        lut_base = SEQID_BRWR * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_BRWR) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(1) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_WRITE));

        lut_base = SEQID_RDEAR * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_RDEAR) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(1) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_READ));

        lut_base = SEQID_WREAR * 4;
        qspi_write32(priv->flags, &regs->lut[lut_base], OPRND0(QSPI_CMD_WREAR) |
                     PAD0(LUT_PAD1) | INSTR0(LUT_CMD) | OPRND1(1) |
                     PAD1(LUT_PAD1) | INSTR1(LUT_WRITE));
#endif
        /* Lock the LUT */
        qspi_write32(priv->flags, &regs->lutkey, LUT_KEY_VALUE);
        qspi_write32(priv->flags, &regs->lckcr, QSPI_LCKCR_LOCK);
}

#if defined(CONFIG_SYS_FSL_QSPI_AHB)
/*
 * If we have changed the content of the flash by writing or erasing,
 * we need to invalidate the AHB buffer. If we do not do so, we may read out
 * the wrong data. The spec tells us reset the AHB domain and Serial Flash
 * domain at the same time.
 */
static inline void qspi_ahb_invalid(struct fsl_qspi_priv *priv)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 reg;

        reg = qspi_read32(priv->flags, &regs->mcr);
        reg |= QSPI_MCR_SWRSTHD_MASK | QSPI_MCR_SWRSTSD_MASK;
        qspi_write32(priv->flags, &regs->mcr, reg);

        /*
         * The minimum delay : 1 AHB + 2 SFCK clocks.
         * Delay 1 us is enough.
         */
        udelay(1);

        reg &= ~(QSPI_MCR_SWRSTHD_MASK | QSPI_MCR_SWRSTSD_MASK);
        qspi_write32(priv->flags, &regs->mcr, reg);
}

/* Read out the data from the AHB buffer. */
static inline void qspi_ahb_read(struct fsl_qspi_priv *priv, u8 *rxbuf, int len)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 mcr_reg;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);

        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);

        /* Read out the data directly from the AHB buffer. */
        memcpy(rxbuf, (u8 *)(priv->cur_amba_base + priv->sf_addr), len);

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}

static void qspi_enable_ddr_mode(struct fsl_qspi_priv *priv)
{
        u32 reg, reg2;
        struct fsl_qspi_regs *regs = priv->regs;

        reg = qspi_read32(priv->flags, &regs->mcr);
        /* Disable the module */
        qspi_write32(priv->flags, &regs->mcr, reg | QSPI_MCR_MDIS_MASK);

        /* Set the Sampling Register for DDR */
        reg2 = qspi_read32(priv->flags, &regs->smpr);
        reg2 &= ~QSPI_SMPR_DDRSMP_MASK;
        reg2 |= (2 << QSPI_SMPR_DDRSMP_SHIFT);
        qspi_write32(priv->flags, &regs->smpr, reg2);

        /* Enable the module again (enable the DDR too) */
        reg |= QSPI_MCR_DDR_EN_MASK;
        /* Enable bit 29 for imx6sx */
        reg |= BIT(29);

        qspi_write32(priv->flags, &regs->mcr, reg);
}

/*
 * There are two different ways to read out the data from the flash:
 *  the "IP Command Read" and the "AHB Command Read".
 *
 * The IC guy suggests we use the "AHB Command Read" which is faster
 * then the "IP Command Read". (What's more is that there is a bug in
 * the "IP Command Read" in the Vybrid.)
 *
 * After we set up the registers for the "AHB Command Read", we can use
 * the memcpy to read the data directly. A "missed" access to the buffer
 * causes the controller to clear the buffer, and use the sequence pointed
 * by the QUADSPI_BFGENCR[SEQID] to initiate a read from the flash.
 */
static void qspi_init_ahb_read(struct fsl_qspi_priv *priv)
{
        struct fsl_qspi_regs *regs = priv->regs;

        /* AHB configuration for access buffer 0/1/2 .*/
        qspi_write32(priv->flags, &regs->buf0cr, QSPI_BUFXCR_INVALID_MSTRID);
        qspi_write32(priv->flags, &regs->buf1cr, QSPI_BUFXCR_INVALID_MSTRID);
        qspi_write32(priv->flags, &regs->buf2cr, QSPI_BUFXCR_INVALID_MSTRID);
        qspi_write32(priv->flags, &regs->buf3cr, QSPI_BUF3CR_ALLMST_MASK |
                     (0x80 << QSPI_BUF3CR_ADATSZ_SHIFT));

        /* We only use the buffer3 */
        qspi_write32(priv->flags, &regs->buf0ind, 0);
        qspi_write32(priv->flags, &regs->buf1ind, 0);
        qspi_write32(priv->flags, &regs->buf2ind, 0);

        /*
         * Set the default lut sequence for AHB Read.
         * Parallel mode is disabled.
         */
        qspi_write32(priv->flags, &regs->bfgencr,
                     SEQID_FAST_READ << QSPI_BFGENCR_SEQID_SHIFT);

        /*Enable DDR Mode*/
        qspi_enable_ddr_mode(priv);
}
#endif

#ifdef CONFIG_SPI_FLASH_BAR
/* Bank register read/write, EAR register read/write */
static void qspi_op_rdbank(struct fsl_qspi_priv *priv, u8 *rxbuf, u32 len)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 reg, mcr_reg, data, seqid;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);
        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);
        qspi_write32(priv->flags, &regs->rbct, QSPI_RBCT_RXBRD_USEIPS);

        qspi_write32(priv->flags, &regs->sfar, priv->cur_amba_base);

        if (priv->cur_seqid == QSPI_CMD_BRRD)
                seqid = SEQID_BRRD;
        else
                seqid = SEQID_RDEAR;

        qspi_write32(priv->flags, &regs->ipcr,
                     (seqid << QSPI_IPCR_SEQID_SHIFT) | len);

        /* Wait previous command complete */
        while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                ;

        while (1) {
                reg = qspi_read32(priv->flags, &regs->rbsr);
                if (reg & QSPI_RBSR_RDBFL_MASK) {
                        data = qspi_read32(priv->flags, &regs->rbdr[0]);
                        data = qspi_endian_xchg(data);
                        memcpy(rxbuf, &data, len);
                        qspi_write32(priv->flags, &regs->mcr,
                                     qspi_read32(priv->flags, &regs->mcr) |
                                     QSPI_MCR_CLR_RXF_MASK);
                        break;
                }
        }

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}
#endif

static void qspi_op_rdid(struct fsl_qspi_priv *priv, u32 *rxbuf, u32 len)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 mcr_reg, rbsr_reg, data, size;
        int i;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);
        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);
        qspi_write32(priv->flags, &regs->rbct, QSPI_RBCT_RXBRD_USEIPS);

        qspi_write32(priv->flags, &regs->sfar, priv->cur_amba_base);

        qspi_write32(priv->flags, &regs->ipcr,
                     (SEQID_RDID << QSPI_IPCR_SEQID_SHIFT) | 0);
        while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                ;

        i = 0;
        while ((RX_BUFFER_SIZE >= len) && (len > 0)) {
                rbsr_reg = qspi_read32(priv->flags, &regs->rbsr);
                if (rbsr_reg & QSPI_RBSR_RDBFL_MASK) {
                        data = qspi_read32(priv->flags, &regs->rbdr[i]);
                        data = qspi_endian_xchg(data);
                        size = (len < 4) ? len : 4;
                        memcpy(rxbuf, &data, size);
                        len -= size;
                        rxbuf++;
                        i++;
                }
        }

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}

#ifndef CONFIG_SYS_FSL_QSPI_AHB
/* If not use AHB read, read data from ip interface */
static void qspi_op_read(struct fsl_qspi_priv *priv, u32 *rxbuf, u32 len)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 mcr_reg, data;
        int i, size;
        u32 to_or_from;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);
        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);
        qspi_write32(priv->flags, &regs->rbct, QSPI_RBCT_RXBRD_USEIPS);

        to_or_from = priv->sf_addr + priv->cur_amba_base;

        while (len > 0) {
                WATCHDOG_RESET();

                qspi_write32(priv->flags, &regs->sfar, to_or_from);

                size = (len > RX_BUFFER_SIZE) ?
                        RX_BUFFER_SIZE : len;

                qspi_write32(priv->flags, &regs->ipcr,
                             (SEQID_FAST_READ << QSPI_IPCR_SEQID_SHIFT) |
                             size);
                while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                        ;

                to_or_from += size;
                len -= size;

                i = 0;
                while ((RX_BUFFER_SIZE >= size) && (size > 0)) {
                        data = qspi_read32(priv->flags, &regs->rbdr[i]);
                        data = qspi_endian_xchg(data);
                        memcpy(rxbuf, &data, 4);
                        rxbuf++;
                        size -= 4;
                        i++;
                }
                qspi_write32(priv->flags, &regs->mcr,
                             qspi_read32(priv->flags, &regs->mcr) |
                             QSPI_MCR_CLR_RXF_MASK);
        }

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}
#endif

static void qspi_op_write(struct fsl_qspi_priv *priv, u8 *txbuf, u32 len)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 mcr_reg, data, reg, status_reg, seqid;
        int i, size, tx_size;
        u32 to_or_from = 0;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);
        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);
        qspi_write32(priv->flags, &regs->rbct, QSPI_RBCT_RXBRD_USEIPS);

        status_reg = 0;
        while ((status_reg & FLASH_STATUS_WEL) != FLASH_STATUS_WEL) {
                WATCHDOG_RESET();

                qspi_write32(priv->flags, &regs->ipcr,
                             (SEQID_WREN << QSPI_IPCR_SEQID_SHIFT) | 0);
                while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                        ;

                qspi_write32(priv->flags, &regs->ipcr,
                             (SEQID_RDSR << QSPI_IPCR_SEQID_SHIFT) | 1);
                while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                        ;

                reg = qspi_read32(priv->flags, &regs->rbsr);
                if (reg & QSPI_RBSR_RDBFL_MASK) {
                        status_reg = qspi_read32(priv->flags, &regs->rbdr[0]);
                        status_reg = qspi_endian_xchg(status_reg);
                }
                qspi_write32(priv->flags, &regs->mcr,
                             qspi_read32(priv->flags, &regs->mcr) |
                             QSPI_MCR_CLR_RXF_MASK);
        }

        /* Default is page programming */
        seqid = SEQID_PP;
#ifdef CONFIG_SPI_FLASH_BAR
        if (priv->cur_seqid == QSPI_CMD_BRWR)
                seqid = SEQID_BRWR;
        else if (priv->cur_seqid == QSPI_CMD_WREAR)
                seqid = SEQID_WREAR;
#endif

        to_or_from = priv->sf_addr + priv->cur_amba_base;

        qspi_write32(priv->flags, &regs->sfar, to_or_from);

        tx_size = (len > TX_BUFFER_SIZE) ?
                TX_BUFFER_SIZE : len;

        size = tx_size / 4;
        for (i = 0; i < size; i++) {
                memcpy(&data, txbuf, 4);
                data = qspi_endian_xchg(data);
                qspi_write32(priv->flags, &regs->tbdr, data);
                txbuf += 4;
        }

        size = tx_size % 4;
        if (size) {
                data = 0;
                memcpy(&data, txbuf, size);
                data = qspi_endian_xchg(data);
                qspi_write32(priv->flags, &regs->tbdr, data);
        }

        qspi_write32(priv->flags, &regs->ipcr,
                     (seqid << QSPI_IPCR_SEQID_SHIFT) | tx_size);
        while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                ;

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}

static void qspi_op_rdsr(struct fsl_qspi_priv *priv, void *rxbuf, u32 len)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 mcr_reg, reg, data;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);
        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);
        qspi_write32(priv->flags, &regs->rbct, QSPI_RBCT_RXBRD_USEIPS);

        qspi_write32(priv->flags, &regs->sfar, priv->cur_amba_base);

        qspi_write32(priv->flags, &regs->ipcr,
                     (SEQID_RDSR << QSPI_IPCR_SEQID_SHIFT) | 0);
        while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                ;

        while (1) {
                reg = qspi_read32(priv->flags, &regs->rbsr);
                if (reg & QSPI_RBSR_RDBFL_MASK) {
                        data = qspi_read32(priv->flags, &regs->rbdr[0]);
                        data = qspi_endian_xchg(data);
                        memcpy(rxbuf, &data, len);
                        qspi_write32(priv->flags, &regs->mcr,
                                     qspi_read32(priv->flags, &regs->mcr) |
                                     QSPI_MCR_CLR_RXF_MASK);
                        break;
                }
        }

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}

static void qspi_op_erase(struct fsl_qspi_priv *priv)
{
        struct fsl_qspi_regs *regs = priv->regs;
        u32 mcr_reg;
        u32 to_or_from = 0;

        mcr_reg = qspi_read32(priv->flags, &regs->mcr);
        qspi_write32(priv->flags, &regs->mcr,
                     QSPI_MCR_CLR_RXF_MASK | QSPI_MCR_CLR_TXF_MASK |
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_END_CFD_LE);
        qspi_write32(priv->flags, &regs->rbct, QSPI_RBCT_RXBRD_USEIPS);

        to_or_from = priv->sf_addr + priv->cur_amba_base;
        qspi_write32(priv->flags, &regs->sfar, to_or_from);

        qspi_write32(priv->flags, &regs->ipcr,
                     (SEQID_WREN << QSPI_IPCR_SEQID_SHIFT) | 0);
        while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                ;

        if (priv->cur_seqid == QSPI_CMD_SE) {
                qspi_write32(priv->flags, &regs->ipcr,
                             (SEQID_SE << QSPI_IPCR_SEQID_SHIFT) | 0);
        } else if (priv->cur_seqid == QSPI_CMD_BE_4K) {
                qspi_write32(priv->flags, &regs->ipcr,
                             (SEQID_BE_4K << QSPI_IPCR_SEQID_SHIFT) | 0);
        }
        while (qspi_read32(priv->flags, &regs->sr) & QSPI_SR_BUSY_MASK)
                ;

        qspi_write32(priv->flags, &regs->mcr, mcr_reg);
}

int qspi_xfer(struct fsl_qspi_priv *priv, unsigned int bitlen,
                const void *dout, void *din, unsigned long flags)
{
        u32 bytes = DIV_ROUND_UP(bitlen, 8);
        static u32 wr_sfaddr;
        u32 txbuf;

        if (dout) {
                if (flags & SPI_XFER_BEGIN) {
                        priv->cur_seqid = *(u8 *)dout;
                        memcpy(&txbuf, dout, 4);
                }

                if (flags == SPI_XFER_END) {
                        priv->sf_addr = wr_sfaddr;
                        qspi_op_write(priv, (u8 *)dout, bytes);
                        return 0;
                }

                if (priv->cur_seqid == QSPI_CMD_FAST_READ) {
                        priv->sf_addr = swab32(txbuf) & OFFSET_BITS_MASK;
                } else if ((priv->cur_seqid == QSPI_CMD_SE) ||
                           (priv->cur_seqid == QSPI_CMD_BE_4K)) {
                        priv->sf_addr = swab32(txbuf) & OFFSET_BITS_MASK;
                        qspi_op_erase(priv);
                } else if (priv->cur_seqid == QSPI_CMD_PP) {
                        wr_sfaddr = swab32(txbuf) & OFFSET_BITS_MASK;
                } else if ((priv->cur_seqid == QSPI_CMD_BRWR) ||
                         (priv->cur_seqid == QSPI_CMD_WREAR)) {
#ifdef CONFIG_SPI_FLASH_BAR
                        wr_sfaddr = 0;
#endif
                }
        }

        if (din) {
                if (priv->cur_seqid == QSPI_CMD_FAST_READ) {
#ifdef CONFIG_SYS_FSL_QSPI_AHB
                        qspi_ahb_read(priv, din, bytes);
#else
                        qspi_op_read(priv, din, bytes);
#endif
                } else if (priv->cur_seqid == QSPI_CMD_RDID)
                        qspi_op_rdid(priv, din, bytes);
                else if (priv->cur_seqid == QSPI_CMD_RDSR)
                        qspi_op_rdsr(priv, din, bytes);
#ifdef CONFIG_SPI_FLASH_BAR
                else if ((priv->cur_seqid == QSPI_CMD_BRRD) ||
                         (priv->cur_seqid == QSPI_CMD_RDEAR)) {
                        priv->sf_addr = 0;
                        qspi_op_rdbank(priv, din, bytes);
                }
#endif
        }

#ifdef CONFIG_SYS_FSL_QSPI_AHB
        if ((priv->cur_seqid == QSPI_CMD_SE) ||
            (priv->cur_seqid == QSPI_CMD_PP) ||
            (priv->cur_seqid == QSPI_CMD_BE_4K) ||
            (priv->cur_seqid == QSPI_CMD_WREAR) ||
            (priv->cur_seqid == QSPI_CMD_BRWR))
                qspi_ahb_invalid(priv);
#endif

        return 0;
}

void qspi_module_disable(struct fsl_qspi_priv *priv, u8 disable)
{
        u32 mcr_val;

        mcr_val = qspi_read32(priv->flags, &priv->regs->mcr);
        if (disable)
                mcr_val |= QSPI_MCR_MDIS_MASK;
        else
                mcr_val &= ~QSPI_MCR_MDIS_MASK;
        qspi_write32(priv->flags, &priv->regs->mcr, mcr_val);
}

void qspi_cfg_smpr(struct fsl_qspi_priv *priv, u32 clear_bits, u32 set_bits)
{
        u32 smpr_val;

        smpr_val = qspi_read32(priv->flags, &priv->regs->smpr);
        smpr_val &= ~clear_bits;
        smpr_val |= set_bits;
        qspi_write32(priv->flags, &priv->regs->smpr, smpr_val);
}
#ifndef CONFIG_DM_SPI
static unsigned long spi_bases[] = {
        QSPI0_BASE_ADDR,
#ifdef CONFIG_MX6SX
        QSPI1_BASE_ADDR,
#endif
};

static unsigned long amba_bases[] = {
        QSPI0_AMBA_BASE,
#ifdef CONFIG_MX6SX
        QSPI1_AMBA_BASE,
#endif
};

static inline struct fsl_qspi *to_qspi_spi(struct spi_slave *slave)
{
        return container_of(slave, struct fsl_qspi, slave);
}

struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
                unsigned int max_hz, unsigned int mode)
{
        struct fsl_qspi *qspi;
        struct fsl_qspi_regs *regs;
        u32 total_size;

        if (bus >= ARRAY_SIZE(spi_bases))
                return NULL;

        if (cs >= FSL_QSPI_FLASH_NUM)
                return NULL;

        qspi = spi_alloc_slave(struct fsl_qspi, bus, cs);
        if (!qspi)
                return NULL;

#ifdef CONFIG_SYS_FSL_QSPI_BE
        qspi->priv.flags |= QSPI_FLAG_REGMAP_ENDIAN_BIG;
#endif

        regs = (struct fsl_qspi_regs *)spi_bases[bus];
        qspi->priv.regs = regs;
        /*
         * According cs, use different amba_base to choose the
         * corresponding flash devices.
         *
         * If not, only one flash device is used even if passing
         * different cs using `sf probe`
         */
        qspi->priv.cur_amba_base = amba_bases[bus] + cs * FSL_QSPI_FLASH_SIZE;

        qspi->slave.max_write_size = TX_BUFFER_SIZE;

        qspi_write32(qspi->priv.flags, &regs->mcr,
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_MDIS_MASK);

        qspi_cfg_smpr(&qspi->priv,
                      ~(QSPI_SMPR_FSDLY_MASK | QSPI_SMPR_DDRSMP_MASK |
                      QSPI_SMPR_FSPHS_MASK | QSPI_SMPR_HSENA_MASK), 0);

        total_size = FSL_QSPI_FLASH_SIZE * FSL_QSPI_FLASH_NUM;
        /*
         * Any read access to non-implemented addresses will provide
         * undefined results.
         *
         * In case single die flash devices, TOP_ADDR_MEMA2 and
         * TOP_ADDR_MEMB2 should be initialized/programmed to
         * TOP_ADDR_MEMA1 and TOP_ADDR_MEMB1 respectively - in effect,
         * setting the size of these devices to 0.  This would ensure
         * that the complete memory map is assigned to only one flash device.
         */
        qspi_write32(qspi->priv.flags, &regs->sfa1ad,
                     FSL_QSPI_FLASH_SIZE | amba_bases[bus]);
        qspi_write32(qspi->priv.flags, &regs->sfa2ad,
                     FSL_QSPI_FLASH_SIZE | amba_bases[bus]);
        qspi_write32(qspi->priv.flags, &regs->sfb1ad,
                     total_size | amba_bases[bus]);
        qspi_write32(qspi->priv.flags, &regs->sfb2ad,
                     total_size | amba_bases[bus]);

        qspi_set_lut(&qspi->priv);

#ifdef CONFIG_SYS_FSL_QSPI_AHB
        qspi_init_ahb_read(&qspi->priv);
#endif

        qspi_module_disable(&qspi->priv, 0);

        return &qspi->slave;
}

void spi_free_slave(struct spi_slave *slave)
{
        struct fsl_qspi *qspi = to_qspi_spi(slave);

        free(qspi);
}

int spi_claim_bus(struct spi_slave *slave)
{
        return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
        /* Nothing to do */
}

int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
                const void *dout, void *din, unsigned long flags)
{
        struct fsl_qspi *qspi = to_qspi_spi(slave);

        return qspi_xfer(&qspi->priv, bitlen, dout, din, flags);
}

void spi_init(void)
{
        /* Nothing to do */
}
#else
static int fsl_qspi_child_pre_probe(struct udevice *dev)
{
        struct spi_slave *slave = dev_get_parent_priv(dev);

        slave->max_write_size = TX_BUFFER_SIZE;

        return 0;
}

static int fsl_qspi_probe(struct udevice *bus)
{
        u32 total_size;
        struct fsl_qspi_platdata *plat = dev_get_platdata(bus);
        struct fsl_qspi_priv *priv = dev_get_priv(bus);
        struct dm_spi_bus *dm_spi_bus;

        dm_spi_bus = bus->uclass_priv;

        dm_spi_bus->max_hz = plat->speed_hz;

        priv->regs = (struct fsl_qspi_regs *)(uintptr_t)plat->reg_base;
        priv->flags = plat->flags;

        priv->speed_hz = plat->speed_hz;
        priv->amba_base[0] = plat->amba_base;
        priv->amba_total_size = plat->amba_total_size;
        priv->flash_num = plat->flash_num;
        priv->num_chipselect = plat->num_chipselect;

        qspi_write32(priv->flags, &priv->regs->mcr,
                     QSPI_MCR_RESERVED_MASK | QSPI_MCR_MDIS_MASK);

        qspi_cfg_smpr(priv, ~(QSPI_SMPR_FSDLY_MASK | QSPI_SMPR_DDRSMP_MASK |
                QSPI_SMPR_FSPHS_MASK | QSPI_SMPR_HSENA_MASK), 0);

        total_size = FSL_QSPI_FLASH_SIZE * FSL_QSPI_FLASH_NUM;
        /*
         * Any read access to non-implemented addresses will provide
         * undefined results.
         *
         * In case single die flash devices, TOP_ADDR_MEMA2 and
         * TOP_ADDR_MEMB2 should be initialized/programmed to
         * TOP_ADDR_MEMA1 and TOP_ADDR_MEMB1 respectively - in effect,
         * setting the size of these devices to 0.  This would ensure
         * that the complete memory map is assigned to only one flash device.
         */
        qspi_write32(priv->flags, &priv->regs->sfa1ad,
                     FSL_QSPI_FLASH_SIZE | priv->amba_base[0]);
        qspi_write32(priv->flags, &priv->regs->sfa2ad,
                     FSL_QSPI_FLASH_SIZE | priv->amba_base[0]);
        qspi_write32(priv->flags, &priv->regs->sfb1ad,
                     total_size | priv->amba_base[0]);
        qspi_write32(priv->flags, &priv->regs->sfb2ad,
                     total_size | priv->amba_base[0]);

        qspi_set_lut(priv);

#ifdef CONFIG_SYS_FSL_QSPI_AHB
        qspi_init_ahb_read(priv);
#endif

        qspi_module_disable(priv, 0);

        return 0;
}

static int fsl_qspi_ofdata_to_platdata(struct udevice *bus)
{
        struct reg_data {
                u32 addr;
                u32 size;
        } regs_data[2];
        struct fsl_qspi_platdata *plat = bus->platdata;
        const void *blob = gd->fdt_blob;
        int node = bus->of_offset;
        int ret, flash_num = 0, subnode;

        if (fdtdec_get_bool(blob, node, "big-endian"))
                plat->flags |= QSPI_FLAG_REGMAP_ENDIAN_BIG;

        ret = fdtdec_get_int_array(blob, node, "reg", (u32 *)regs_data,
                                   sizeof(regs_data)/sizeof(u32));

        if (ret) {
                debug("Error: can't get base addresses (ret = %d)!\n", ret);
                return -ENOMEM;
        }

        /* Count flash numbers */
        fdt_for_each_subnode(blob, subnode, node)
                ++flash_num;

        if (flash_num == 0) {
                debug("Error: Missing flashes!\n");
                return -ENODEV;
        }

        plat->speed_hz = fdtdec_get_int(blob, node, "spi-max-frequency",
                                        FSL_QSPI_DEFAULT_SCK_FREQ);
        plat->num_chipselect = fdtdec_get_int(blob, node, "num-cs",
                                              FSL_QSPI_MAX_CHIPSELECT_NUM);

        plat->reg_base = regs_data[0].addr;
        plat->amba_base = regs_data[1].addr;
        plat->amba_total_size = regs_data[1].size;
        plat->flash_num = flash_num;

        debug("%s: regs=<0x%x> <0x%x, 0x%x>, max-frequency=%d, endianess=%s\n",
              __func__,
              plat->reg_base,
              plat->amba_base,
              plat->amba_total_size,
              plat->speed_hz,
              plat->flags & QSPI_FLAG_REGMAP_ENDIAN_BIG ? "be" : "le"
              );

        return 0;
}

static int fsl_qspi_xfer(struct udevice *dev, unsigned int bitlen,
                const void *dout, void *din, unsigned long flags)
{
        struct fsl_qspi_priv *priv;
        struct udevice *bus;

        bus = dev->parent;
        priv = dev_get_priv(bus);

        return qspi_xfer(priv, bitlen, dout, din, flags);
}

static int fsl_qspi_claim_bus(struct udevice *dev)
{
        struct fsl_qspi_priv *priv;
        struct udevice *bus;
        struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);

        bus = dev->parent;
        priv = dev_get_priv(bus);

        priv->cur_amba_base =
                priv->amba_base[0] + FSL_QSPI_FLASH_SIZE * slave_plat->cs;

        qspi_module_disable(priv, 0);

        return 0;
}

static int fsl_qspi_release_bus(struct udevice *dev)
{
        struct fsl_qspi_priv *priv;
        struct udevice *bus;

        bus = dev->parent;
        priv = dev_get_priv(bus);

        qspi_module_disable(priv, 1);

        return 0;
}

static int fsl_qspi_set_speed(struct udevice *bus, uint speed)
{
        /* Nothing to do */
        return 0;
}

static int fsl_qspi_set_mode(struct udevice *bus, uint mode)
{
        /* Nothing to do */
        return 0;
}

static const struct dm_spi_ops fsl_qspi_ops = {
        .claim_bus      = fsl_qspi_claim_bus,
        .release_bus    = fsl_qspi_release_bus,
        .xfer           = fsl_qspi_xfer,
        .set_speed      = fsl_qspi_set_speed,
        .set_mode       = fsl_qspi_set_mode,
};

static const struct udevice_id fsl_qspi_ids[] = {
        { .compatible = "fsl,vf610-qspi" },
        { .compatible = "fsl,imx6sx-qspi" },
        { }
};

U_BOOT_DRIVER(fsl_qspi) = {
        .name   = "fsl_qspi",
        .id     = UCLASS_SPI,
        .of_match = fsl_qspi_ids,
        .ops    = &fsl_qspi_ops,
        .ofdata_to_platdata = fsl_qspi_ofdata_to_platdata,
        .platdata_auto_alloc_size = sizeof(struct fsl_qspi_platdata),
        .priv_auto_alloc_size = sizeof(struct fsl_qspi_priv),
        .probe  = fsl_qspi_probe,
        .child_pre_probe = fsl_qspi_child_pre_probe,
};
#endif