// SPDX-License-Identifier: GPL-2.0+
//
// Copyright 2013 Freescale Semiconductor, Inc.
//
// Freescale DSPI driver
// This file contains a driver for the Freescale DSPI

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-fsl-dspi.h>

#define DRIVER_NAME                     "fsl-dspi"

#define SPI_MCR                         0x00
#define SPI_MCR_MASTER                  BIT(31)
#define SPI_MCR_PCSIS(x)                ((x) << 16)
#define SPI_MCR_CLR_TXF                 BIT(11)
#define SPI_MCR_CLR_RXF                 BIT(10)
#define SPI_MCR_XSPI                    BIT(3)

#define SPI_TCR                         0x08
#define SPI_TCR_GET_TCNT(x)             (((x) & GENMASK(31, 16)) >> 16)

#define SPI_CTAR(x)                     (0x0c + (((x) & GENMASK(1, 0)) * 4))
#define SPI_CTAR_FMSZ(x)                (((x) << 27) & GENMASK(30, 27))
#define SPI_CTAR_CPOL                   BIT(26)
#define SPI_CTAR_CPHA                   BIT(25)
#define SPI_CTAR_LSBFE                  BIT(24)
#define SPI_CTAR_PCSSCK(x)              (((x) << 22) & GENMASK(23, 22))
#define SPI_CTAR_PASC(x)                (((x) << 20) & GENMASK(21, 20))
#define SPI_CTAR_PDT(x)                 (((x) << 18) & GENMASK(19, 18))
#define SPI_CTAR_PBR(x)                 (((x) << 16) & GENMASK(17, 16))
#define SPI_CTAR_CSSCK(x)               (((x) << 12) & GENMASK(15, 12))
#define SPI_CTAR_ASC(x)                 (((x) << 8) & GENMASK(11, 8))
#define SPI_CTAR_DT(x)                  (((x) << 4) & GENMASK(7, 4))
#define SPI_CTAR_BR(x)                  ((x) & GENMASK(3, 0))
#define SPI_CTAR_SCALE_BITS             0xf

#define SPI_CTAR0_SLAVE                 0x0c

#define SPI_SR                          0x2c
#define SPI_SR_TCFQF                    BIT(31)
#define SPI_SR_EOQF                     BIT(28)
#define SPI_SR_TFUF                     BIT(27)
#define SPI_SR_TFFF                     BIT(25)
#define SPI_SR_CMDTCF                   BIT(23)
#define SPI_SR_SPEF                     BIT(21)
#define SPI_SR_RFOF                     BIT(19)
#define SPI_SR_TFIWF                    BIT(18)
#define SPI_SR_RFDF                     BIT(17)
#define SPI_SR_CMDFFF                   BIT(16)
#define SPI_SR_CLEAR                    (SPI_SR_TCFQF | SPI_SR_EOQF | \
                                        SPI_SR_TFUF | SPI_SR_TFFF | \
                                        SPI_SR_CMDTCF | SPI_SR_SPEF | \
                                        SPI_SR_RFOF | SPI_SR_TFIWF | \
                                        SPI_SR_RFDF | SPI_SR_CMDFFF)

#define SPI_RSER_TFFFE                  BIT(25)
#define SPI_RSER_TFFFD                  BIT(24)
#define SPI_RSER_RFDFE                  BIT(17)
#define SPI_RSER_RFDFD                  BIT(16)

#define SPI_RSER                        0x30
#define SPI_RSER_TCFQE                  BIT(31)
#define SPI_RSER_EOQFE                  BIT(28)
#define SPI_RSER_CMDTCFE                BIT(23)

#define SPI_PUSHR                       0x34
#define SPI_PUSHR_CMD_CONT              BIT(15)
#define SPI_PUSHR_CMD_CTAS(x)           (((x) << 12 & GENMASK(14, 12)))
#define SPI_PUSHR_CMD_EOQ               BIT(11)
#define SPI_PUSHR_CMD_CTCNT             BIT(10)
#define SPI_PUSHR_CMD_PCS(x)            (BIT(x) & GENMASK(5, 0))

#define SPI_PUSHR_SLAVE                 0x34

#define SPI_POPR                        0x38

#define SPI_TXFR0                       0x3c
#define SPI_TXFR1                       0x40
#define SPI_TXFR2                       0x44
#define SPI_TXFR3                       0x48
#define SPI_RXFR0                       0x7c
#define SPI_RXFR1                       0x80
#define SPI_RXFR2                       0x84
#define SPI_RXFR3                       0x88

#define SPI_CTARE(x)                    (0x11c + (((x) & GENMASK(1, 0)) * 4))
#define SPI_CTARE_FMSZE(x)              (((x) & 0x1) << 16)
#define SPI_CTARE_DTCP(x)               ((x) & 0x7ff)

#define SPI_SREX                        0x13c

#define SPI_FRAME_BITS(bits)            SPI_CTAR_FMSZ((bits) - 1)
#define SPI_FRAME_EBITS(bits)           SPI_CTARE_FMSZE(((bits) - 1) >> 4)

#define DMA_COMPLETION_TIMEOUT          msecs_to_jiffies(3000)

struct chip_data {
        u32                     ctar_val;
};

enum dspi_trans_mode {
        DSPI_EOQ_MODE = 0,
        DSPI_XSPI_MODE,
        DSPI_DMA_MODE,
};

struct fsl_dspi_devtype_data {
        enum dspi_trans_mode    trans_mode;
        u8                      max_clock_factor;
        int                     fifo_size;
};

enum {
        LS1021A,
        LS1012A,
        LS1028A,
        LS1043A,
        LS1046A,
        LS2080A,
        LS2085A,
        LX2160A,
        MCF5441X,
        VF610,
};

static const struct fsl_dspi_devtype_data devtype_data[] = {
        [VF610] = {
                .trans_mode             = DSPI_DMA_MODE,
                .max_clock_factor       = 2,
                .fifo_size              = 4,
        },
        [LS1021A] = {
                /* Has A-011218 DMA erratum */
                .trans_mode             = DSPI_XSPI_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 4,
        },
        [LS1012A] = {
                /* Has A-011218 DMA erratum */
                .trans_mode             = DSPI_XSPI_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 16,
        },
        [LS1028A] = {
                .trans_mode             = DSPI_XSPI_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 4,
        },
        [LS1043A] = {
                /* Has A-011218 DMA erratum */
                .trans_mode             = DSPI_XSPI_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 16,
        },
        [LS1046A] = {
                /* Has A-011218 DMA erratum */
                .trans_mode             = DSPI_XSPI_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 16,
        },
        [LS2080A] = {
                .trans_mode             = DSPI_DMA_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 4,
        },
        [LS2085A] = {
                .trans_mode             = DSPI_DMA_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 4,
        },
        [LX2160A] = {
                .trans_mode             = DSPI_DMA_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 4,
        },
        [MCF5441X] = {
                .trans_mode             = DSPI_EOQ_MODE,
                .max_clock_factor       = 8,
                .fifo_size              = 16,
        },
};

struct fsl_dspi_dma {
        u32                                     *tx_dma_buf;
        struct dma_chan                         *chan_tx;
        dma_addr_t                              tx_dma_phys;
        struct completion                       cmd_tx_complete;
        struct dma_async_tx_descriptor          *tx_desc;

        u32                                     *rx_dma_buf;
        struct dma_chan                         *chan_rx;
        dma_addr_t                              rx_dma_phys;
        struct completion                       cmd_rx_complete;
        struct dma_async_tx_descriptor          *rx_desc;
};

struct fsl_dspi {
        struct spi_controller                   *ctlr;
        struct platform_device                  *pdev;

        struct regmap                           *regmap;
        struct regmap                           *regmap_pushr;
        int                                     irq;
        struct clk                              *clk;

        struct spi_transfer                     *cur_transfer;
        struct spi_message                      *cur_msg;
        struct chip_data                        *cur_chip;
        size_t                                  progress;
        size_t                                  len;
        const void                              *tx;
        void                                    *rx;
        u16                                     tx_cmd;
        const struct fsl_dspi_devtype_data      *devtype_data;

        struct completion                       xfer_done;

        struct fsl_dspi_dma                     *dma;

        int                                     oper_word_size;
        int                                     oper_bits_per_word;

        int                                     words_in_flight;

        /*
         * Offsets for CMD and TXDATA within SPI_PUSHR when accessed
         * individually (in XSPI mode)
         */
        int                                     pushr_cmd;
        int                                     pushr_tx;

        void (*host_to_dev)(struct fsl_dspi *dspi, u32 *txdata);
        void (*dev_to_host)(struct fsl_dspi *dspi, u32 rxdata);
};

static void dspi_native_host_to_dev(struct fsl_dspi *dspi, u32 *txdata)
{
        memcpy(txdata, dspi->tx, dspi->oper_word_size);
        dspi->tx += dspi->oper_word_size;
}

static void dspi_native_dev_to_host(struct fsl_dspi *dspi, u32 rxdata)
{
        memcpy(dspi->rx, &rxdata, dspi->oper_word_size);
        dspi->rx += dspi->oper_word_size;
}

static void dspi_8on32_host_to_dev(struct fsl_dspi *dspi, u32 *txdata)
{
        *txdata = cpu_to_be32(*(u32 *)dspi->tx);
        dspi->tx += sizeof(u32);
}

static void dspi_8on32_dev_to_host(struct fsl_dspi *dspi, u32 rxdata)
{
        *(u32 *)dspi->rx = be32_to_cpu(rxdata);
        dspi->rx += sizeof(u32);
}

static void dspi_8on16_host_to_dev(struct fsl_dspi *dspi, u32 *txdata)
{
        *txdata = cpu_to_be16(*(u16 *)dspi->tx);
        dspi->tx += sizeof(u16);
}

static void dspi_8on16_dev_to_host(struct fsl_dspi *dspi, u32 rxdata)
{
        *(u16 *)dspi->rx = be16_to_cpu(rxdata);
        dspi->rx += sizeof(u16);
}

static void dspi_16on32_host_to_dev(struct fsl_dspi *dspi, u32 *txdata)
{
        u16 hi = *(u16 *)dspi->tx;
        u16 lo = *(u16 *)(dspi->tx + 2);

        *txdata = (u32)hi << 16 | lo;
        dspi->tx += sizeof(u32);
}

static void dspi_16on32_dev_to_host(struct fsl_dspi *dspi, u32 rxdata)
{
        u16 hi = rxdata & 0xffff;
        u16 lo = rxdata >> 16;

        *(u16 *)dspi->rx = lo;
        *(u16 *)(dspi->rx + 2) = hi;
        dspi->rx += sizeof(u32);
}

/*
 * Pop one word from the TX buffer for pushing into the
 * PUSHR register (TX FIFO)
 */
static u32 dspi_pop_tx(struct fsl_dspi *dspi)
{
        u32 txdata = 0;

        if (dspi->tx)
                dspi->host_to_dev(dspi, &txdata);
        dspi->len -= dspi->oper_word_size;
        return txdata;
}

/* Prepare one TX FIFO entry (txdata plus cmd) */
static u32 dspi_pop_tx_pushr(struct fsl_dspi *dspi)
{
        u16 cmd = dspi->tx_cmd, data = dspi_pop_tx(dspi);

        if (spi_controller_is_slave(dspi->ctlr))
                return data;

        if (dspi->len > 0)
                cmd |= SPI_PUSHR_CMD_CONT;
        return cmd << 16 | data;
}

/* Push one word to the RX buffer from the POPR register (RX FIFO) */
static void dspi_push_rx(struct fsl_dspi *dspi, u32 rxdata)
{
        if (!dspi->rx)
                return;
        dspi->dev_to_host(dspi, rxdata);
}

static void dspi_tx_dma_callback(void *arg)
{
        struct fsl_dspi *dspi = arg;
        struct fsl_dspi_dma *dma = dspi->dma;

        complete(&dma->cmd_tx_complete);
}

static void dspi_rx_dma_callback(void *arg)
{
        struct fsl_dspi *dspi = arg;
        struct fsl_dspi_dma *dma = dspi->dma;
        int i;

        if (dspi->rx) {
                for (i = 0; i < dspi->words_in_flight; i++)
                        dspi_push_rx(dspi, dspi->dma->rx_dma_buf[i]);
        }

        complete(&dma->cmd_rx_complete);
}

static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi)
{
        struct device *dev = &dspi->pdev->dev;
        struct fsl_dspi_dma *dma = dspi->dma;
        int time_left;
        int i;

        for (i = 0; i < dspi->words_in_flight; i++)
                dspi->dma->tx_dma_buf[i] = dspi_pop_tx_pushr(dspi);

        dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
                                        dma->tx_dma_phys,
                                        dspi->words_in_flight *
                                        DMA_SLAVE_BUSWIDTH_4_BYTES,
                                        DMA_MEM_TO_DEV,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!dma->tx_desc) {
                dev_err(dev, "Not able to get desc for DMA xfer\n");
                return -EIO;
        }

        dma->tx_desc->callback = dspi_tx_dma_callback;
        dma->tx_desc->callback_param = dspi;
        if (dma_submit_error(dmaengine_submit(dma->tx_desc))) {
                dev_err(dev, "DMA submit failed\n");
                return -EINVAL;
        }

        dma->rx_desc = dmaengine_prep_slave_single(dma->chan_rx,
                                        dma->rx_dma_phys,
                                        dspi->words_in_flight *
                                        DMA_SLAVE_BUSWIDTH_4_BYTES,
                                        DMA_DEV_TO_MEM,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!dma->rx_desc) {
                dev_err(dev, "Not able to get desc for DMA xfer\n");
                return -EIO;
        }

        dma->rx_desc->callback = dspi_rx_dma_callback;
        dma->rx_desc->callback_param = dspi;
        if (dma_submit_error(dmaengine_submit(dma->rx_desc))) {
                dev_err(dev, "DMA submit failed\n");
                return -EINVAL;
        }

        reinit_completion(&dspi->dma->cmd_rx_complete);
        reinit_completion(&dspi->dma->cmd_tx_complete);

        dma_async_issue_pending(dma->chan_rx);
        dma_async_issue_pending(dma->chan_tx);

        if (spi_controller_is_slave(dspi->ctlr)) {
                wait_for_completion_interruptible(&dspi->dma->cmd_rx_complete);
                return 0;
        }

        time_left = wait_for_completion_timeout(&dspi->dma->cmd_tx_complete,
                                                DMA_COMPLETION_TIMEOUT);
        if (time_left == 0) {
                dev_err(dev, "DMA tx timeout\n");
                dmaengine_terminate_all(dma->chan_tx);
                dmaengine_terminate_all(dma->chan_rx);
                return -ETIMEDOUT;
        }

        time_left = wait_for_completion_timeout(&dspi->dma->cmd_rx_complete,
                                                DMA_COMPLETION_TIMEOUT);
        if (time_left == 0) {
                dev_err(dev, "DMA rx timeout\n");
                dmaengine_terminate_all(dma->chan_tx);
                dmaengine_terminate_all(dma->chan_rx);
                return -ETIMEDOUT;
        }

        return 0;
}

static void dspi_setup_accel(struct fsl_dspi *dspi);

static int dspi_dma_xfer(struct fsl_dspi *dspi)
{
        struct spi_message *message = dspi->cur_msg;
        struct device *dev = &dspi->pdev->dev;
        int ret = 0;

        /*
         * dspi->len gets decremented by dspi_pop_tx_pushr in
         * dspi_next_xfer_dma_submit
         */
        while (dspi->len) {
                /* Figure out operational bits-per-word for this chunk */
                dspi_setup_accel(dspi);

                dspi->words_in_flight = dspi->len / dspi->oper_word_size;
                if (dspi->words_in_flight > dspi->devtype_data->fifo_size)
                        dspi->words_in_flight = dspi->devtype_data->fifo_size;

                message->actual_length += dspi->words_in_flight *
                                          dspi->oper_word_size;

                ret = dspi_next_xfer_dma_submit(dspi);
                if (ret) {
                        dev_err(dev, "DMA transfer failed\n");
                        break;
                }
        }

        return ret;
}

static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr)
{
        int dma_bufsize = dspi->devtype_data->fifo_size * 2;
        struct device *dev = &dspi->pdev->dev;
        struct dma_slave_config cfg;
        struct fsl_dspi_dma *dma;
        int ret;

        dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
        if (!dma)
                return -ENOMEM;

        dma->chan_rx = dma_request_chan(dev, "rx");
        if (IS_ERR(dma->chan_rx)) {
                dev_err(dev, "rx dma channel not available\n");
                ret = PTR_ERR(dma->chan_rx);
                return ret;
        }

        dma->chan_tx = dma_request_chan(dev, "tx");
        if (IS_ERR(dma->chan_tx)) {
                dev_err(dev, "tx dma channel not available\n");
                ret = PTR_ERR(dma->chan_tx);
                goto err_tx_channel;
        }

        dma->tx_dma_buf = dma_alloc_coherent(dma->chan_tx->device->dev,
                                             dma_bufsize, &dma->tx_dma_phys,
                                             GFP_KERNEL);
        if (!dma->tx_dma_buf) {
                ret = -ENOMEM;
                goto err_tx_dma_buf;
        }

        dma->rx_dma_buf = dma_alloc_coherent(dma->chan_rx->device->dev,
                                             dma_bufsize, &dma->rx_dma_phys,
                                             GFP_KERNEL);
        if (!dma->rx_dma_buf) {
                ret = -ENOMEM;
                goto err_rx_dma_buf;
        }

        cfg.src_addr = phy_addr + SPI_POPR;
        cfg.dst_addr = phy_addr + SPI_PUSHR;
        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
        cfg.src_maxburst = 1;
        cfg.dst_maxburst = 1;

        cfg.direction = DMA_DEV_TO_MEM;
        ret = dmaengine_slave_config(dma->chan_rx, &cfg);
        if (ret) {
                dev_err(dev, "can't configure rx dma channel\n");
                ret = -EINVAL;
                goto err_slave_config;
        }

        cfg.direction = DMA_MEM_TO_DEV;
        ret = dmaengine_slave_config(dma->chan_tx, &cfg);
        if (ret) {
                dev_err(dev, "can't configure tx dma channel\n");
                ret = -EINVAL;
                goto err_slave_config;
        }

        dspi->dma = dma;
        init_completion(&dma->cmd_tx_complete);
        init_completion(&dma->cmd_rx_complete);

        return 0;

err_slave_config:
        dma_free_coherent(dma->chan_rx->device->dev,
                          dma_bufsize, dma->rx_dma_buf, dma->rx_dma_phys);
err_rx_dma_buf:
        dma_free_coherent(dma->chan_tx->device->dev,
                          dma_bufsize, dma->tx_dma_buf, dma->tx_dma_phys);
err_tx_dma_buf:
        dma_release_channel(dma->chan_tx);
err_tx_channel:
        dma_release_channel(dma->chan_rx);

        devm_kfree(dev, dma);
        dspi->dma = NULL;

        return ret;
}

static void dspi_release_dma(struct fsl_dspi *dspi)
{
        int dma_bufsize = dspi->devtype_data->fifo_size * 2;
        struct fsl_dspi_dma *dma = dspi->dma;

        if (!dma)
                return;

        if (dma->chan_tx) {
                dma_unmap_single(dma->chan_tx->device->dev, dma->tx_dma_phys,
                                 dma_bufsize, DMA_TO_DEVICE);
                dma_release_channel(dma->chan_tx);
        }

        if (dma->chan_rx) {
                dma_unmap_single(dma->chan_rx->device->dev, dma->rx_dma_phys,
                                 dma_bufsize, DMA_FROM_DEVICE);
                dma_release_channel(dma->chan_rx);
        }
}

static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
                           unsigned long clkrate)
{
        /* Valid baud rate pre-scaler values */
        int pbr_tbl[4] = {2, 3, 5, 7};
        int brs[16] = { 2,      4,      6,      8,
                        16,     32,     64,     128,
                        256,    512,    1024,   2048,
                        4096,   8192,   16384,  32768 };
        int scale_needed, scale, minscale = INT_MAX;
        int i, j;

        scale_needed = clkrate / speed_hz;
        if (clkrate % speed_hz)
                scale_needed++;

        for (i = 0; i < ARRAY_SIZE(brs); i++)
                for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) {
                        scale = brs[i] * pbr_tbl[j];
                        if (scale >= scale_needed) {
                                if (scale < minscale) {
                                        minscale = scale;
                                        *br = i;
                                        *pbr = j;
                                }
                                break;
                        }
                }

        if (minscale == INT_MAX) {
                pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n",
                        speed_hz, clkrate);
                *pbr = ARRAY_SIZE(pbr_tbl) - 1;
                *br =  ARRAY_SIZE(brs) - 1;
        }
}

static void ns_delay_scale(char *psc, char *sc, int delay_ns,
                           unsigned long clkrate)
{
        int scale_needed, scale, minscale = INT_MAX;
        int pscale_tbl[4] = {1, 3, 5, 7};
        u32 remainder;
        int i, j;

        scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC,
                                   &remainder);
        if (remainder)
                scale_needed++;

        for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++)
                for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) {
                        scale = pscale_tbl[i] * (2 << j);
                        if (scale >= scale_needed) {
                                if (scale < minscale) {
                                        minscale = scale;
                                        *psc = i;
                                        *sc = j;
                                }
                                break;
                        }
                }

        if (minscale == INT_MAX) {
                pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value",
                        delay_ns, clkrate);
                *psc = ARRAY_SIZE(pscale_tbl) - 1;
                *sc = SPI_CTAR_SCALE_BITS;
        }
}

static void dspi_pushr_write(struct fsl_dspi *dspi)
{
        regmap_write(dspi->regmap, SPI_PUSHR, dspi_pop_tx_pushr(dspi));
}

static void dspi_pushr_cmd_write(struct fsl_dspi *dspi, u16 cmd)
{
        /*
         * The only time when the PCS doesn't need continuation after this word
         * is when it's last. We need to look ahead, because we actually call
         * dspi_pop_tx (the function that decrements dspi->len) _after_
         * dspi_pushr_cmd_write with XSPI mode. As for how much in advance? One
         * word is enough. If there's more to transmit than that,
         * dspi_xspi_write will know to split the FIFO writes in 2, and
         * generate a new PUSHR command with the final word that will have PCS
         * deasserted (not continued) here.
         */
        if (dspi->len > dspi->oper_word_size)
                cmd |= SPI_PUSHR_CMD_CONT;
        regmap_write(dspi->regmap_pushr, dspi->pushr_cmd, cmd);
}

static void dspi_pushr_txdata_write(struct fsl_dspi *dspi, u16 txdata)
{
        regmap_write(dspi->regmap_pushr, dspi->pushr_tx, txdata);
}

static void dspi_xspi_fifo_write(struct fsl_dspi *dspi, int num_words)
{
        int num_bytes = num_words * dspi->oper_word_size;
        u16 tx_cmd = dspi->tx_cmd;

        /*
         * If the PCS needs to de-assert (i.e. we're at the end of the buffer
         * and cs_change does not want the PCS to stay on), then we need a new
         * PUSHR command, since this one (for the body of the buffer)
         * necessarily has the CONT bit set.
         * So send one word less during this go, to force a split and a command
         * with a single word next time, when CONT will be unset.
         */
        if (!(dspi->tx_cmd & SPI_PUSHR_CMD_CONT) && num_bytes == dspi->len)
                tx_cmd |= SPI_PUSHR_CMD_EOQ;

        /* Update CTARE */
        regmap_write(dspi->regmap, SPI_CTARE(0),
                     SPI_FRAME_EBITS(dspi->oper_bits_per_word) |
                     SPI_CTARE_DTCP(num_words));

        /*
         * Write the CMD FIFO entry first, and then the two
         * corresponding TX FIFO entries (or one...).
         */
        dspi_pushr_cmd_write(dspi, tx_cmd);

        /* Fill TX FIFO with as many transfers as possible */
        while (num_words--) {
                u32 data = dspi_pop_tx(dspi);

                dspi_pushr_txdata_write(dspi, data & 0xFFFF);
                if (dspi->oper_bits_per_word > 16)
                        dspi_pushr_txdata_write(dspi, data >> 16);
        }
}

static void dspi_eoq_fifo_write(struct fsl_dspi *dspi, int num_words)
{
        u16 xfer_cmd = dspi->tx_cmd;

        /* Fill TX FIFO with as many transfers as possible */
        while (num_words--) {
                dspi->tx_cmd = xfer_cmd;
                /* Request EOQF for last transfer in FIFO */
                if (num_words == 0)
                        dspi->tx_cmd |= SPI_PUSHR_CMD_EOQ;
                /* Write combined TX FIFO and CMD FIFO entry */
                dspi_pushr_write(dspi);
        }
}

static u32 dspi_popr_read(struct fsl_dspi *dspi)
{
        u32 rxdata = 0;

        regmap_read(dspi->regmap, SPI_POPR, &rxdata);
        return rxdata;
}

static void dspi_fifo_read(struct fsl_dspi *dspi)
{
        int num_fifo_entries = dspi->words_in_flight;

        /* Read one FIFO entry and push to rx buffer */
        while (num_fifo_entries--)
                dspi_push_rx(dspi, dspi_popr_read(dspi));
}

static void dspi_setup_accel(struct fsl_dspi *dspi)
{
        struct spi_transfer *xfer = dspi->cur_transfer;
        bool odd = !!(dspi->len & 1);

        /* No accel for frames not multiple of 8 bits at the moment */
        if (xfer->bits_per_word % 8)
                goto no_accel;

        if (!odd && dspi->len <= dspi->devtype_data->fifo_size * 2) {
                dspi->oper_bits_per_word = 16;
        } else if (odd && dspi->len <= dspi->devtype_data->fifo_size) {
                dspi->oper_bits_per_word = 8;
        } else {
                /* Start off with maximum supported by hardware */
                if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
                        dspi->oper_bits_per_word = 32;
                else
                        dspi->oper_bits_per_word = 16;

                /*
                 * And go down only if the buffer can't be sent with
                 * words this big
                 */
                do {
                        if (dspi->len >= DIV_ROUND_UP(dspi->oper_bits_per_word, 8))
                                break;

                        dspi->oper_bits_per_word /= 2;
                } while (dspi->oper_bits_per_word > 8);
        }

        if (xfer->bits_per_word == 8 && dspi->oper_bits_per_word == 32) {
                dspi->dev_to_host = dspi_8on32_dev_to_host;
                dspi->host_to_dev = dspi_8on32_host_to_dev;
        } else if (xfer->bits_per_word == 8 && dspi->oper_bits_per_word == 16) {
                dspi->dev_to_host = dspi_8on16_dev_to_host;
                dspi->host_to_dev = dspi_8on16_host_to_dev;
        } else if (xfer->bits_per_word == 16 && dspi->oper_bits_per_word == 32) {
                dspi->dev_to_host = dspi_16on32_dev_to_host;
                dspi->host_to_dev = dspi_16on32_host_to_dev;
        } else {
no_accel:
                dspi->dev_to_host = dspi_native_dev_to_host;
                dspi->host_to_dev = dspi_native_host_to_dev;
                dspi->oper_bits_per_word = xfer->bits_per_word;
        }

        dspi->oper_word_size = DIV_ROUND_UP(dspi->oper_bits_per_word, 8);

        /*
         * Update CTAR here (code is common for EOQ, XSPI and DMA modes).
         * We will update CTARE in the portion specific to XSPI, when we
         * also know the preload value (DTCP).
         */
        regmap_write(dspi->regmap, SPI_CTAR(0),
                     dspi->cur_chip->ctar_val |
                     SPI_FRAME_BITS(dspi->oper_bits_per_word));
}

static void dspi_fifo_write(struct fsl_dspi *dspi)
{
        int num_fifo_entries = dspi->devtype_data->fifo_size;
        struct spi_transfer *xfer = dspi->cur_transfer;
        struct spi_message *msg = dspi->cur_msg;
        int num_words, num_bytes;

        dspi_setup_accel(dspi);

        /* In XSPI mode each 32-bit word occupies 2 TX FIFO entries */
        if (dspi->oper_word_size == 4)
                num_fifo_entries /= 2;

        /*
         * Integer division intentionally trims off odd (or non-multiple of 4)
         * numbers of bytes at the end of the buffer, which will be sent next
         * time using a smaller oper_word_size.
         */
        num_words = dspi->len / dspi->oper_word_size;
        if (num_words > num_fifo_entries)
                num_words = num_fifo_entries;

        /* Update total number of bytes that were transferred */
        num_bytes = num_words * dspi->oper_word_size;
        msg->actual_length += num_bytes;
        dspi->progress += num_bytes / DIV_ROUND_UP(xfer->bits_per_word, 8);

        /*
         * Update shared variable for use in the next interrupt (both in
         * dspi_fifo_read and in dspi_fifo_write).
         */
        dspi->words_in_flight = num_words;

        spi_take_timestamp_pre(dspi->ctlr, xfer, dspi->progress, !dspi->irq);

        if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE)
                dspi_eoq_fifo_write(dspi, num_words);
        else
                dspi_xspi_fifo_write(dspi, num_words);
        /*
         * Everything after this point is in a potential race with the next
         * interrupt, so we must never use dspi->words_in_flight again since it
         * might already be modified by the next dspi_fifo_write.
         */

        spi_take_timestamp_post(dspi->ctlr, dspi->cur_transfer,
                                dspi->progress, !dspi->irq);
}

static int dspi_rxtx(struct fsl_dspi *dspi)
{
        dspi_fifo_read(dspi);

        if (!dspi->len)
                /* Success! */
                return 0;

        dspi_fifo_write(dspi);

        return -EINPROGRESS;
}

static int dspi_poll(struct fsl_dspi *dspi)
{
        int tries = 1000;
        u32 spi_sr;

        do {
                regmap_read(dspi->regmap, SPI_SR, &spi_sr);
                regmap_write(dspi->regmap, SPI_SR, spi_sr);

                if (spi_sr & (SPI_SR_EOQF | SPI_SR_CMDTCF))
                        break;
        } while (--tries);

        if (!tries)
                return -ETIMEDOUT;

        return dspi_rxtx(dspi);
}

static irqreturn_t dspi_interrupt(int irq, void *dev_id)
{
        struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
        u32 spi_sr;

        regmap_read(dspi->regmap, SPI_SR, &spi_sr);
        regmap_write(dspi->regmap, SPI_SR, spi_sr);

        if (!(spi_sr & (SPI_SR_EOQF | SPI_SR_CMDTCF)))
                return IRQ_NONE;

        if (dspi_rxtx(dspi) == 0)
                complete(&dspi->xfer_done);

        return IRQ_HANDLED;
}

static int dspi_transfer_one_message(struct spi_controller *ctlr,
                                     struct spi_message *message)
{
        struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);
        struct spi_device *spi = message->spi;
        struct spi_transfer *transfer;
        int status = 0;

        message->actual_length = 0;

        list_for_each_entry(transfer, &message->transfers, transfer_list) {
                dspi->cur_transfer = transfer;
                dspi->cur_msg = message;
                dspi->cur_chip = spi_get_ctldata(spi);
                /* Prepare command word for CMD FIFO */
                dspi->tx_cmd = SPI_PUSHR_CMD_CTAS(0) |
                               SPI_PUSHR_CMD_PCS(spi->chip_select);
                if (list_is_last(&dspi->cur_transfer->transfer_list,
                                 &dspi->cur_msg->transfers)) {
                        /* Leave PCS activated after last transfer when
                         * cs_change is set.
                         */
                        if (transfer->cs_change)
                                dspi->tx_cmd |= SPI_PUSHR_CMD_CONT;
                } else {
                        /* Keep PCS active between transfers in same message
                         * when cs_change is not set, and de-activate PCS
                         * between transfers in the same message when
                         * cs_change is set.
                         */
                        if (!transfer->cs_change)
                                dspi->tx_cmd |= SPI_PUSHR_CMD_CONT;
                }

                dspi->tx = transfer->tx_buf;
                dspi->rx = transfer->rx_buf;
                dspi->len = transfer->len;
                dspi->progress = 0;

                regmap_update_bits(dspi->regmap, SPI_MCR,
                                   SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
                                   SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);

                spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer,
                                       dspi->progress, !dspi->irq);

                if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
                        status = dspi_dma_xfer(dspi);
                } else {
                        dspi_fifo_write(dspi);

                        if (dspi->irq) {
                                wait_for_completion(&dspi->xfer_done);
                                reinit_completion(&dspi->xfer_done);
                        } else {
                                do {
                                        status = dspi_poll(dspi);
                                } while (status == -EINPROGRESS);
                        }
                }
                if (status)
                        break;

                spi_transfer_delay_exec(transfer);
        }

        message->status = status;
        spi_finalize_current_message(ctlr);

        return status;
}

static int dspi_setup(struct spi_device *spi)
{
        struct fsl_dspi *dspi = spi_controller_get_devdata(spi->controller);
        unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0;
        u32 cs_sck_delay = 0, sck_cs_delay = 0;
        struct fsl_dspi_platform_data *pdata;
        unsigned char pasc = 0, asc = 0;
        struct chip_data *chip;
        unsigned long clkrate;

        /* Only alloc on first setup */
        chip = spi_get_ctldata(spi);
        if (chip == NULL) {
                chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
                if (!chip)
                        return -ENOMEM;
        }

        pdata = dev_get_platdata(&dspi->pdev->dev);

        if (!pdata) {
                of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay",
                                     &cs_sck_delay);

                of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay",

                                     &sck_cs_delay);
        } else {
                cs_sck_delay = pdata->cs_sck_delay;
                sck_cs_delay = pdata->sck_cs_delay;
        }

        clkrate = clk_get_rate(dspi->clk);
        hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate);

        /* Set PCS to SCK delay scale values */
        ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate);

        /* Set After SCK delay scale values */
        ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate);

        chip->ctar_val = 0;
        if (spi->mode & SPI_CPOL)
                chip->ctar_val |= SPI_CTAR_CPOL;
        if (spi->mode & SPI_CPHA)
                chip->ctar_val |= SPI_CTAR_CPHA;

        if (!spi_controller_is_slave(dspi->ctlr)) {
                chip->ctar_val |= SPI_CTAR_PCSSCK(pcssck) |
                                  SPI_CTAR_CSSCK(cssck) |
                                  SPI_CTAR_PASC(pasc) |
                                  SPI_CTAR_ASC(asc) |
                                  SPI_CTAR_PBR(pbr) |
                                  SPI_CTAR_BR(br);

                if (spi->mode & SPI_LSB_FIRST)
                        chip->ctar_val |= SPI_CTAR_LSBFE;
        }

        spi_set_ctldata(spi, chip);

        return 0;
}

static void dspi_cleanup(struct spi_device *spi)
{
        struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);

        dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n",
                spi->controller->bus_num, spi->chip_select);

        kfree(chip);
}

static const struct of_device_id fsl_dspi_dt_ids[] = {
        {
                .compatible = "fsl,vf610-dspi",
                .data = &devtype_data[VF610],
        }, {
                .compatible = "fsl,ls1021a-v1.0-dspi",
                .data = &devtype_data[LS1021A],
        }, {
                .compatible = "fsl,ls1012a-dspi",
                .data = &devtype_data[LS1012A],
        }, {
                .compatible = "fsl,ls1028a-dspi",
                .data = &devtype_data[LS1028A],
        }, {
                .compatible = "fsl,ls1043a-dspi",
                .data = &devtype_data[LS1043A],
        }, {
                .compatible = "fsl,ls1046a-dspi",
                .data = &devtype_data[LS1046A],
        }, {
                .compatible = "fsl,ls2080a-dspi",
                .data = &devtype_data[LS2080A],
        }, {
                .compatible = "fsl,ls2085a-dspi",
                .data = &devtype_data[LS2085A],
        }, {
                .compatible = "fsl,lx2160a-dspi",
                .data = &devtype_data[LX2160A],
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);

#ifdef CONFIG_PM_SLEEP
static int dspi_suspend(struct device *dev)
{
        struct spi_controller *ctlr = dev_get_drvdata(dev);
        struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);

        spi_controller_suspend(ctlr);
        clk_disable_unprepare(dspi->clk);

        pinctrl_pm_select_sleep_state(dev);

        return 0;
}

static int dspi_resume(struct device *dev)
{
        struct spi_controller *ctlr = dev_get_drvdata(dev);
        struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);
        int ret;

        pinctrl_pm_select_default_state(dev);

        ret = clk_prepare_enable(dspi->clk);
        if (ret)
                return ret;
        spi_controller_resume(ctlr);

        return 0;
}
#endif /* CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);

static const struct regmap_range dspi_volatile_ranges[] = {
        regmap_reg_range(SPI_MCR, SPI_TCR),
        regmap_reg_range(SPI_SR, SPI_SR),
        regmap_reg_range(SPI_PUSHR, SPI_RXFR3),
};

static const struct regmap_access_table dspi_volatile_table = {
        .yes_ranges     = dspi_volatile_ranges,
        .n_yes_ranges   = ARRAY_SIZE(dspi_volatile_ranges),
};

static const struct regmap_config dspi_regmap_config = {
        .reg_bits       = 32,
        .val_bits       = 32,
        .reg_stride     = 4,
        .max_register   = 0x88,
        .volatile_table = &dspi_volatile_table,
};

static const struct regmap_range dspi_xspi_volatile_ranges[] = {
        regmap_reg_range(SPI_MCR, SPI_TCR),
        regmap_reg_range(SPI_SR, SPI_SR),
        regmap_reg_range(SPI_PUSHR, SPI_RXFR3),
        regmap_reg_range(SPI_SREX, SPI_SREX),
};

static const struct regmap_access_table dspi_xspi_volatile_table = {
        .yes_ranges     = dspi_xspi_volatile_ranges,
        .n_yes_ranges   = ARRAY_SIZE(dspi_xspi_volatile_ranges),
};

static const struct regmap_config dspi_xspi_regmap_config[] = {
        {
                .reg_bits       = 32,
                .val_bits       = 32,
                .reg_stride     = 4,
                .max_register   = 0x13c,
                .volatile_table = &dspi_xspi_volatile_table,
        },
        {
                .name           = "pushr",
                .reg_bits       = 16,
                .val_bits       = 16,
                .reg_stride     = 2,
                .max_register   = 0x2,
        },
};

static int dspi_init(struct fsl_dspi *dspi)
{
        unsigned int mcr;

        /* Set idle states for all chip select signals to high */
        mcr = SPI_MCR_PCSIS(GENMASK(dspi->ctlr->num_chipselect - 1, 0));

        if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
                mcr |= SPI_MCR_XSPI;
        if (!spi_controller_is_slave(dspi->ctlr))
                mcr |= SPI_MCR_MASTER;

        regmap_write(dspi->regmap, SPI_MCR, mcr);
        regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR);

        switch (dspi->devtype_data->trans_mode) {
        case DSPI_EOQ_MODE:
                regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
                break;
        case DSPI_XSPI_MODE:
                regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_CMDTCFE);
                break;
        case DSPI_DMA_MODE:
                regmap_write(dspi->regmap, SPI_RSER,
                             SPI_RSER_TFFFE | SPI_RSER_TFFFD |
                             SPI_RSER_RFDFE | SPI_RSER_RFDFD);
                break;
        default:
                dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
                        dspi->devtype_data->trans_mode);
                return -EINVAL;
        }

        return 0;
}

static int dspi_slave_abort(struct spi_master *master)
{
        struct fsl_dspi *dspi = spi_master_get_devdata(master);

        /*
         * Terminate all pending DMA transactions for the SPI working
         * in SLAVE mode.
         */
        if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
                dmaengine_terminate_sync(dspi->dma->chan_rx);
                dmaengine_terminate_sync(dspi->dma->chan_tx);
        }

        /* Clear the internal DSPI RX and TX FIFO buffers */
        regmap_update_bits(dspi->regmap, SPI_MCR,
                           SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
                           SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);

        return 0;
}

/*
 * EOQ mode will inevitably deassert its PCS signal on last word in a queue
 * (hardware limitation), so we need to inform the spi_device that larger
 * buffers than the FIFO size are going to have the chip select randomly
 * toggling, so it has a chance to adapt its message sizes.
 */
static size_t dspi_max_message_size(struct spi_device *spi)
{
        struct fsl_dspi *dspi = spi_controller_get_devdata(spi->controller);

        if (dspi->devtype_data->trans_mode == DSPI_EOQ_MODE)
                return dspi->devtype_data->fifo_size;

        return SIZE_MAX;
}

static int dspi_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        const struct regmap_config *regmap_config;
        struct fsl_dspi_platform_data *pdata;
        struct spi_controller *ctlr;
        int ret, cs_num, bus_num = -1;
        struct fsl_dspi *dspi;
        struct resource *res;
        void __iomem *base;
        bool big_endian;

        ctlr = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
        if (!ctlr)
                return -ENOMEM;

        dspi = spi_controller_get_devdata(ctlr);
        dspi->pdev = pdev;
        dspi->ctlr = ctlr;

        ctlr->setup = dspi_setup;
        ctlr->transfer_one_message = dspi_transfer_one_message;
        ctlr->max_message_size = dspi_max_message_size;
        ctlr->dev.of_node = pdev->dev.of_node;

        ctlr->cleanup = dspi_cleanup;
        ctlr->slave_abort = dspi_slave_abort;
        ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;

        pdata = dev_get_platdata(&pdev->dev);
        if (pdata) {
                ctlr->num_chipselect = pdata->cs_num;
                ctlr->bus_num = pdata->bus_num;

                /* Only Coldfire uses platform data */
                dspi->devtype_data = &devtype_data[MCF5441X];
                big_endian = true;
        } else {

                ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
                if (ret < 0) {
                        dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
                        goto out_ctlr_put;
                }
                ctlr->num_chipselect = cs_num;

                of_property_read_u32(np, "bus-num", &bus_num);
                ctlr->bus_num = bus_num;

                if (of_property_read_bool(np, "spi-slave"))
                        ctlr->slave = true;

                dspi->devtype_data = of_device_get_match_data(&pdev->dev);
                if (!dspi->devtype_data) {
                        dev_err(&pdev->dev, "can't get devtype_data\n");
                        ret = -EFAULT;
                        goto out_ctlr_put;
                }

                big_endian = of_device_is_big_endian(np);
        }
        if (big_endian) {
                dspi->pushr_cmd = 0;
                dspi->pushr_tx = 2;
        } else {
                dspi->pushr_cmd = 2;
                dspi->pushr_tx = 0;
        }

        if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
                ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
        else
                ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(base)) {
                ret = PTR_ERR(base);
                goto out_ctlr_put;
        }

        if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE)
                regmap_config = &dspi_xspi_regmap_config[0];
        else
                regmap_config = &dspi_regmap_config;
        dspi->regmap = devm_regmap_init_mmio(&pdev->dev, base, regmap_config);
        if (IS_ERR(dspi->regmap)) {
                dev_err(&pdev->dev, "failed to init regmap: %ld\n",
                                PTR_ERR(dspi->regmap));
                ret = PTR_ERR(dspi->regmap);
                goto out_ctlr_put;
        }

        if (dspi->devtype_data->trans_mode == DSPI_XSPI_MODE) {
                dspi->regmap_pushr = devm_regmap_init_mmio(
                        &pdev->dev, base + SPI_PUSHR,
                        &dspi_xspi_regmap_config[1]);
                if (IS_ERR(dspi->regmap_pushr)) {
                        dev_err(&pdev->dev,
                                "failed to init pushr regmap: %ld\n",
                                PTR_ERR(dspi->regmap_pushr));
                        ret = PTR_ERR(dspi->regmap_pushr);
                        goto out_ctlr_put;
                }
        }

        dspi->clk = devm_clk_get(&pdev->dev, "dspi");
        if (IS_ERR(dspi->clk)) {
                ret = PTR_ERR(dspi->clk);
                dev_err(&pdev->dev, "unable to get clock\n");
                goto out_ctlr_put;
        }
        ret = clk_prepare_enable(dspi->clk);
        if (ret)
                goto out_ctlr_put;

        ret = dspi_init(dspi);
        if (ret)
                goto out_clk_put;

        dspi->irq = platform_get_irq(pdev, 0);
        if (dspi->irq <= 0) {
                dev_info(&pdev->dev,
                         "can't get platform irq, using poll mode\n");
                dspi->irq = 0;
                goto poll_mode;
        }

        ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt,
                               IRQF_SHARED, pdev->name, dspi);
        if (ret < 0) {
                dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
                goto out_clk_put;
        }

        init_completion(&dspi->xfer_done);

poll_mode:

        if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
                ret = dspi_request_dma(dspi, res->start);
                if (ret < 0) {
                        dev_err(&pdev->dev, "can't get dma channels\n");
                        goto out_clk_put;
                }
        }

        ctlr->max_speed_hz =
                clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;

        if (dspi->devtype_data->trans_mode != DSPI_DMA_MODE)
                ctlr->ptp_sts_supported = true;

        platform_set_drvdata(pdev, ctlr);

        ret = spi_register_controller(ctlr);
        if (ret != 0) {
                dev_err(&pdev->dev, "Problem registering DSPI ctlr\n");
                goto out_clk_put;
        }

        return ret;

out_clk_put:
        clk_disable_unprepare(dspi->clk);
out_ctlr_put:
        spi_controller_put(ctlr);

        return ret;
}

static int dspi_remove(struct platform_device *pdev)
{
        struct spi_controller *ctlr = platform_get_drvdata(pdev);
        struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);

        /* Disconnect from the SPI framework */
        dspi_release_dma(dspi);
        clk_disable_unprepare(dspi->clk);
        spi_unregister_controller(dspi->ctlr);

        return 0;
}

static struct platform_driver fsl_dspi_driver = {
        .driver.name            = DRIVER_NAME,
        .driver.of_match_table  = fsl_dspi_dt_ids,
        .driver.owner           = THIS_MODULE,
        .driver.pm              = &dspi_pm,
        .probe                  = dspi_probe,
        .remove                 = dspi_remove,
};
module_platform_driver(fsl_dspi_driver);

MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);