SPIMaster.c

/* Copyright (c) Codethink Ltd. All rights reserved.
   Licensed under the MIT License. */

#include "SPIMaster.h"
#include "Common.h"
#include "NVIC.h"
#include "mt3620/spi.h"
#include "mt3620/dma.h"

// This is the maximum number of globbed transactions we allow to queue
#define SPI_MASTER_TRANSFER_COUNT_MAX 16

typedef enum {
    SPI_MASTER_TRANSFER_WRITE,
    SPI_MASTER_TRANSFER_READ,
    SPI_MASTER_TRANSFER_FULL_DUPLEX,
} SPIMaster_TransferType;

typedef struct {
    uint8_t            type;
    uint8_t            opcodeLen;
    uint8_t            payloadLen;
    uint8_t            transferCount;
    const SPITransfer *transfer;
} SPIMaster_TransferGlob;

struct SPIMaster {
    uint32_t                id;
    bool                    open;
    bool                    dma;
    SPI_IdleLevel           idleLevel;
    uint32_t                csLine;
    void                    (*csCallback)(SPIMaster*, bool);
    bool                    csEnable;
    void                    (*callback)(int32_t, uintptr_t);
    void                    (*callbackUser)(int32_t, uintptr_t, void*);
    void                   *userData;
    SPIMaster_TransferGlob  glob[SPI_MASTER_TRANSFER_COUNT_MAX];
    unsigned                globCount, globTransferred;
    int32_t                 dataCount;
};

static SPIMaster spiContext[MT3620_SPI_COUNT] = { 0 };

// Note that we currently reserve a buffer in sysram for each possible ISU interface
// for very sysram constrained applications it may make sense to modify this so that
// you only reserve the buffers that are actually needed.
static __attribute__((section(".sysram"))) mt3620_spi_dma_cfg_t SPIMaster_DmaConfig[MT3620_SPI_COUNT] = { 0 };

#define SPI_PRIORITY 2

int32_t SPIMaster_SelectIdleLineLevel(SPIMaster *handle, SPI_IdleLevel level)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }

    switch (level) {
    case SPI_IDLE_LEVEL_LOW:
    case SPI_IDLE_LEVEL_HIGH:
    case SPI_IDLE_LEVEL_DONT_CARE:
        break;
    default:
        return ERROR_UNSUPPORTED;
    }

    if (handle->globCount > handle->globTransferred) {
        return ERROR_BUSY;
    }

    handle->idleLevel = level;
    return ERROR_NONE;
}

int32_t SPIMaster_Select(SPIMaster *handle, unsigned csLine)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }

    if (csLine > MT3620_CS_MAX) {
        return ERROR_UNSUPPORTED;
    }

    handle->csLine     = csLine;
    handle->csEnable   = true;
    handle->csCallback = NULL;

    // Set the chip select line.
    SPIMaster_DmaConfig[handle->id].smmr.rs_slave_sel = csLine;

    return ERROR_NONE;
}

int32_t SPIMaster_SelectEnable(SPIMaster *handle, bool enable)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }

    handle->csEnable = enable;
    if (!handle->csCallback) {
        SPIMaster_DmaConfig[handle->id].smmr.rs_slave_sel = enable ? handle->csLine : MT3620_CS_NULL;
    }

    return ERROR_NONE;
}

int32_t SPIMaster_SetSelectLineCallback(
    SPIMaster *handle,
    void       (*csCallback)(SPIMaster *handle, bool select))
{
    if (!handle) {
        return ERROR_PARAMETER;
    }

    handle->csCallback = csCallback;
    handle->csEnable   = (csCallback != NULL);
    handle->csLine     = MT3620_CS_NULL;

    SPIMaster_DmaConfig[handle->id].smmr.rs_slave_sel = MT3620_CS_NULL;

    return ERROR_NONE;
}

int32_t SPIMaster_Configure(SPIMaster *handle, bool cpol, bool cpha, uint32_t busSpeed)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }

    // There's an errata for low busSpeed values when CPOL and CPHA are 0, so we increase the minimum.
    if ((cpol == 0) && (cpha == 0) && (busSpeed < 250000)) {
        return ERROR_UNSUPPORTED;
    }

    // We round up the clock-speed division here to get the closest speed below the target.
    unsigned rs_clk_sel = ((MT3620_SPI_HCLK + (busSpeed - 1)) / busSpeed);
    rs_clk_sel = (rs_clk_sel < 2 ? 0 : (rs_clk_sel - 2));

    // Check we're not below the minimum speed.
    if (rs_clk_sel > 4095) {
        return ERROR_UNSUPPORTED;
    }

    mt3620_spi_dma_cfg_t *cfg = &SPIMaster_DmaConfig[handle->id];
    cfg->smmr.cpol          = cpol;       // Set polarity for CPOL setting.
    cfg->smmr.cpha          = cpha;       // Set polarity for CPHA setting.
    cfg->smmr.rs_clk_sel    = rs_clk_sel; // Set serial clock SPI_CLK.
    cfg->smmr.more_buf_mode = 1;          // Select SPI buffer size.
    cfg->smmr.lsb_first     = false;      // Select MSB first.
    cfg->smmr.int_en        = true;       // Enable interrupts.

    return ERROR_NONE;
}

int32_t SPIMaster_DMAEnable(SPIMaster *handle, bool enable)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }

    if (handle->dma == enable) {
        return ERROR_NONE;
    }

    if (MT3620_DMA_FIELD_READ(MT3620_SPI_DMA_TX(handle->id), start, str)) {
        return ERROR_BUSY;
    }

    MT3620_SPI_FIELD_WRITE(handle->id, cspol, dma_mode, enable);
    handle->dma = enable;
    return ERROR_NONE;
}

int32_t SPIMaster_ConfigureDriveStrength(SPIMaster *handle, unsigned drive)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }

    if (drive == 0) {
        return ERROR_PARAMETER;
    }

    if (drive < 4) {
        return ERROR_UNSUPPORTED;
    }

    drive = ((drive - 4) >> 2);
    if (drive > 3) {
        drive = 3;
    }

    // Note that at the time of writing this register address is not documented
    // in the functional spec.
    volatile uint32_t *paddrv = (uint32_t *)((0x38070000 + (0x00010000 * handle->id)) | 0x0070);

    uint32_t mask = *paddrv;
    mask |= (drive << 0); // SCK
    mask |= (drive << 2); // MOSI
    mask |= (drive << 4); // MISO
    mask |= (drive << 6); // CSA
    mask |= (drive << 8); // CSB
    *paddrv = mask;

    return ERROR_NONE;
}


static inline unsigned SPIMaster_UnitToID(Platform_Unit unit)
{
    if ((unit < MT3620_UNIT_ISU0) || (unit > MT3620_UNIT_ISU5)) {
        return MT3620_SPI_COUNT;
    }
    return (unit - MT3620_UNIT_ISU0);
}

SPIMaster *SPIMaster_Open(Platform_Unit unit)
{
    unsigned id = SPIMaster_UnitToID(unit);
    if ((id >= MT3620_SPI_COUNT) || (spiContext[id].open)) {
        return NULL;
    }

    spiContext[id].id                 = id;
    spiContext[id].open               = true;
    spiContext[id].dma                = true;
    spiContext[id].idleLevel          = SPI_IDLE_LEVEL_HIGH;
    spiContext[id].csLine             = MT3620_CS_NULL;
    spiContext[id].csCallback         = NULL;
    spiContext[id].csEnable           = false;
    spiContext[id].callback           = NULL;
    spiContext[id].callbackUser       = NULL;
    spiContext[id].userData           = NULL;
    spiContext[id].globCount          = 0;
    spiContext[id].globTransferred    = 0;
    spiContext[id].dataCount          = 0;

    // Select the CS line.
    int32_t status = SPIMaster_Select(&spiContext[id], 0);
    if (status != ERROR_NONE) {
        return NULL;
    }

    // Call SPIMaster_Configure to set up the chip for the SPI to 2 MHz by default.
    status = SPIMaster_Configure(&spiContext[id], 0, 0, 2000000);
    if (status != ERROR_NONE) {
        return NULL;
    }

    // Enable and Set the NVIC interrupt priority.
    NVIC_EnableIRQ(MT3620_SPI_INTERRUPT(id), SPI_PRIORITY);

    // Hard-code start to true in DMA transfers so transfer starts.
    mt3620_spi_dma_cfg_t *cfg = &SPIMaster_DmaConfig[id];
    cfg->stcsr.spi_master_start = true;

    volatile mt3620_dma_t * const tx_dma = &mt3620_dma[MT3620_SPI_DMA_TX(id)];
    mt3620_dma_global->ch_en_set = (1U << MT3620_SPI_DMA_TX(id));
    MT3620_DMA_FIELD_WRITE(MT3620_SPI_DMA_TX(id), start, str, false);
    mt3620_dma_con_t dma_con_tx = { .mask = tx_dma->con };
    dma_con_tx.dir   = 0;
    dma_con_tx.wpen  = false;
    dma_con_tx.wpsd  = 0;
    dma_con_tx.iten  = false;
    dma_con_tx.hiten = false;
    dma_con_tx.dreq  = false;
    dma_con_tx.dinc  = 0;
    dma_con_tx.sinc  = 1;
    dma_con_tx.size  = 2;
    tx_dma->con = dma_con_tx.mask;
    tx_dma->fixaddr = (uint32_t *)&mt3620_spi[id]->dataport;
    tx_dma->pgmaddr = (uint32_t *)&SPIMaster_DmaConfig[id];

    // Enable DMA mode.
    MT3620_SPI_FIELD_WRITE(id, cspol, dma_mode, true);

    // We have to set all buffers to know the the MOSI line idle level.
    // This is due to a hardware bug in the SPI adapter on the MT3620.
    if (spiContext[id].idleLevel != SPI_IDLE_LEVEL_DONT_CARE) {
        uint32_t fill = (spiContext[id].idleLevel == SPI_IDLE_LEVEL_LOW
            ? 0x00000000 : 0xFFFFFFFF);

        unsigned i;
        for (i = 0; i < (MT3620_SPI_BUFFER_SIZE_HALF_DUPLEX / 4); i++) {
            mt3620_spi[id]->sdor[i] = fill;
        }
        mt3620_spi[id]->soar = fill;
    }

    MT3620_SPI_FIELD_WRITE(id, stcsr, spi_master_start, false);

    // Clear interrupt flag
    (void)mt3620_spi[id]->scsr;

    return &spiContext[id];
}

void SPIMaster_Close(SPIMaster *handle)
{
    if (!handle || !handle->open) {
        return;
    }

    mt3620_dma_global->ch_en_clr = (1U << MT3620_SPI_DMA_TX(handle->id));
    MT3620_SPI_FIELD_WRITE(handle->id, stcsr, spi_master_start, false); // Stop transfers
    MT3620_SPI_FIELD_WRITE(handle->id, smmr , int_en          , false); // Disable interrupts.
    MT3620_SPI_FIELD_WRITE(handle->id, cspol, dma_mode        , false); // Disable DMA mode.

    // Disable NVIC interrupts.
    NVIC_DisableIRQ(MT3620_SPI_INTERRUPT(handle->id));

    handle->open = false;
}


static inline void SPIMaster_WordCopy(volatile void *dst, volatile void *src, uintptr_t count)
{
    volatile uint32_t *udst = dst;
    volatile uint32_t *usrc = src;
    uintptr_t i;
    for (i = 0; i < count; i++) {
        udst[i] = usrc[i];
    }
}

static int32_t SPIMaster_TransferGlobQueue(SPIMaster *handle, SPIMaster_TransferGlob *glob)
{
    mt3620_spi_dma_cfg_t *cfg = &SPIMaster_DmaConfig[handle->id];

    switch (glob->type) {
    case SPI_MASTER_TRANSFER_WRITE:
        cfg->smmr.both_directional_data_mode = false;

        cfg->smbcr.mosi_bit_cnt = (glob->payloadLen * 8);
        cfg->smbcr.miso_bit_cnt = 0;
        cfg->smbcr.cmd_bit_cnt  = (glob->opcodeLen  * 8);
        break;

    case SPI_MASTER_TRANSFER_READ:
        cfg->smmr.both_directional_data_mode = false;

        cfg->smbcr.mosi_bit_cnt = 0;
        cfg->smbcr.miso_bit_cnt = (glob->payloadLen * 8);
        cfg->smbcr.cmd_bit_cnt  = (glob->opcodeLen  * 8);
        break;

    case SPI_MASTER_TRANSFER_FULL_DUPLEX:
        cfg->smmr.both_directional_data_mode = true;

        cfg->smbcr.mosi_bit_cnt = (glob->payloadLen * 8);
        cfg->smbcr.miso_bit_cnt = (glob->payloadLen * 8);
        cfg->smbcr.cmd_bit_cnt  = (glob->opcodeLen  * 8);
        break;

    default:
        // This should never happen.
        return ERROR;
    }

    unsigned o = 0;
    unsigned t = 0;
    if (glob->opcodeLen >= 0) {
        const SPITransfer *transfer = &glob->transfer[t];

        // Reverse byte order of opcode as SPI is big-endian.
        uint32_t mask = 0xFFFFFFFF;
        const uint8_t *writeData = transfer->writeData;
        unsigned i;
        for (i = 0; i < glob->opcodeLen; i++) {
            mask <<= 8;
            mask |= writeData[i];
        }
        cfg->soar.mask = mask;

        if (glob->opcodeLen >= transfer->length) {
            t++;
        } else {
            o += glob->opcodeLen;
        }
    }

    unsigned p = 0;
    uint8_t *sdor = (uint8_t *)cfg->sdor;
    for (; t < glob->transferCount; t++) {
        const SPITransfer *transfer = &glob->transfer[t];

        if (transfer->writeData) {
            const uint8_t *writeData = transfer->writeData;
            __builtin_memcpy(&sdor[p], &writeData[o], (transfer->length - o));
        } else if (glob->type == SPI_MASTER_TRANSFER_FULL_DUPLEX) {
            uint8_t idleLevel = (handle->idleLevel == SPI_IDLE_LEVEL_LOW ? 0x00 : 0xFF);
            __builtin_memset(&sdor[p], idleLevel, (transfer->length - o));
        }

        p += (transfer->length - o);
        o  = 0;
    }

    // This workaround is required to make the MOSI line idle at known level due to SPI bug.
    if (handle->idleLevel != SPI_IDLE_LEVEL_DONT_CARE) {
        sdor[p % MT3620_SPI_BUFFER_SIZE_HALF_DUPLEX] =
            (handle->idleLevel == SPI_IDLE_LEVEL_LOW ? 0x00 : 0xFF);
    }

    if (handle->dma) {
        unsigned index = MT3620_SPI_DMA_TX(handle->id);
        mt3620_dma[index].pgmaddr = (uint32_t*)&SPIMaster_DmaConfig[handle->id];
        mt3620_dma[index].count = (sizeof(mt3620_spi_dma_cfg_t) / 4);
        MT3620_DMA_FIELD_WRITE(index, start, str, true);
    } else {
        SPIMaster_WordCopy(&mt3620_spi[handle->id]->soar, &SPIMaster_DmaConfig[handle->id], 11);
        mt3620_spi[handle->id]->stcsr = SPIMaster_DmaConfig[handle->id].stcsr.mask;
    }

    return ERROR_NONE;
}

static int32_t SPIMaster_TransferSequentialAsyncGlob(
    SPIMaster              *handle,
    SPIMaster_TransferGlob *glob,
    uint32_t                count,
    void(*callback)     (int32_t status, uintptr_t dataCount),
    void(*callbackUser) (int32_t status, uintptr_t dataCount, void *userData),
    void                   *userData)
{
    if (!handle->open) {
        return ERROR_HANDLE_CLOSED;
    }
    if (count == 0) {
        return ERROR_PARAMETER;
    }

    handle->callback        = callback;
    handle->callbackUser    = callbackUser;
    handle->userData        = userData;
    handle->globCount       = count;
    handle->globTransferred = 0;
    handle->dataCount       = 0;

    if (handle->csEnable && handle->csCallback) {
        handle->csCallback(handle, true);
    }

    int32_t status = SPIMaster_TransferGlobQueue(handle, &glob[0]);
    if (status != ERROR_NONE) {
        handle->callback  = NULL;
        handle->globCount = 0;
    }

    return status;
}

static int32_t SPIMaster_TransferGlobNew(
        SPIMaster              *handle,
        const SPITransfer      *transfer,
        SPIMaster_TransferGlob *glob)
{
    if ((!transfer->writeData && !transfer->readData)
        || (transfer->length == 0)) {
        return ERROR_PARAMETER;
    }

    // MT3620 doesn't support full-duplex without write preamble.
    if (transfer->writeData && transfer->readData) {
        return ERROR_UNSUPPORTED;
    }

    uint8_t idleByte = (handle->idleLevel == SPI_IDLE_LEVEL_DONT_CARE ? 0 : 1);

    if (transfer->writeData) {
        if (transfer->length > (
            MT3620_SPI_BUFFER_SIZE_FULL_DUPLEX - idleByte + MT3620_SPI_OPCODE_SIZE)) {
            return ERROR_UNSUPPORTED;
        }

        glob->type = SPI_MASTER_TRANSFER_WRITE;
        glob->opcodeLen = (transfer->length > MT3620_SPI_OPCODE_SIZE
            ? MT3620_SPI_OPCODE_SIZE : transfer->length);
        glob->payloadLen = (transfer->length - glob->opcodeLen);
    } else {
        if (transfer->length > MT3620_SPI_BUFFER_SIZE_HALF_DUPLEX) {
            return ERROR_UNSUPPORTED;
        }

        glob->type       = SPI_MASTER_TRANSFER_READ;
        glob->opcodeLen  = 0;
        glob->payloadLen = transfer->length;
    }

    glob->transferCount = 1;
    glob->transfer      = transfer;
    return ERROR_NONE;
}

static bool SPIMaster_TransferGlobAppend(
    SPIMaster              *handle,
    const SPITransfer      *transfer,
    uint32_t                count,
    SPIMaster_TransferGlob *glob)
{
    if ((count == 0)
        || (!transfer[0].writeData && !transfer[0].readData)
        || (transfer[0].length == 0)) {
        return ERROR_PARAMETER;
    }

    // If next transfer is a write but the one after is full-duplex, we don't glob it
    // as we need to glob a full-duplex onto a write due to hardware limitations.
    if (transfer[0].writeData && !transfer[0].readData && (count >= 2)
        && transfer[1].writeData && transfer[1].readData) {
        return false;
    }

    uint8_t idleByte = (handle->idleLevel == SPI_IDLE_LEVEL_DONT_CARE ? 0 : 1);

    if (glob->type == SPI_MASTER_TRANSFER_READ) {
        if (transfer[0].writeData) {
            if (glob->opcodeLen == 0) {
                // We can't append a write/full-duplex to a half-duplex read.
                return false;
            }

            if ((glob->payloadLen + transfer[0].length)
                > (MT3620_SPI_BUFFER_SIZE_FULL_DUPLEX - idleByte))
            {
                return false;
            }

            glob->type = SPI_MASTER_TRANSFER_FULL_DUPLEX;
        } else {
            if ((glob->payloadLen + transfer[0].length)
                > MT3620_SPI_BUFFER_SIZE_HALF_DUPLEX) {
                return false;
            }
        }
    } else if (glob->type == SPI_MASTER_TRANSFER_WRITE) {
        if (transfer[0].writeData && !transfer[0].readData) {
            // Can't glob writes if payload would exceed length limit.
            if ((glob->payloadLen + transfer[0].length)
                > (MT3620_SPI_BUFFER_SIZE_HALF_DUPLEX - idleByte)) {
                return false;
            }
        } else if (transfer[0].readData && !transfer[0].writeData) {
            if (glob->payloadLen == 0) {
                if (transfer[0].length > MT3620_SPI_BUFFER_SIZE_HALF_DUPLEX) {
                    return false;
                }

                glob->type = SPI_MASTER_TRANSFER_READ;
            } else if ((glob->payloadLen + transfer[0].length)
                <= (MT3620_SPI_BUFFER_SIZE_FULL_DUPLEX - idleByte)) {
                glob->type = SPI_MASTER_TRANSFER_FULL_DUPLEX;
            } else {
                return false;
            }
        } else {
            if ((glob->payloadLen + transfer[0].length)
                > (MT3620_SPI_BUFFER_SIZE_FULL_DUPLEX - idleByte)) {
                return false;
            }

            glob->type = SPI_MASTER_TRANSFER_FULL_DUPLEX;
        }
    } else {
        if ((glob->payloadLen + transfer[0].length)
            > (MT3620_SPI_BUFFER_SIZE_FULL_DUPLEX - idleByte)) {
            return false;
        }
    }

    glob->transferCount++;
    glob->payloadLen += transfer->length;
    return true;
}

static int32_t SPIMaster_TransferSequentialAsync_Wrapper(
    SPIMaster   *handle,
    SPITransfer *transfer,
    uint32_t     count,
    void        (*callback)(
        int32_t status, uintptr_t data_count),
    void        (*callbackUser)(
        int32_t status, uintptr_t data_count, void *userData),
    void        *userData)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }
    if (!transfer || (count == 0)) {
        return ERROR_PARAMETER;
    }

    SPIMaster_TransferGlob *glob = handle->glob;

    unsigned t = 0, g = 0;
    int32_t status;
    status = SPIMaster_TransferGlobNew(handle, &transfer[t++], &glob[g]);
    if (status != ERROR_NONE) {
        return status;
    }

    for (; t < count; t++) {
        if (!SPIMaster_TransferGlobAppend(handle, &transfer[t], (count - t), &glob[g])) {
            if (++g >= SPI_MASTER_TRANSFER_COUNT_MAX) {
                return ERROR_UNSUPPORTED;
            }

            status = SPIMaster_TransferGlobNew(handle, &transfer[t], &glob[g]);
            if (status != ERROR_NONE) {
                return status;
            }
        }
    }

    handle->globCount = (g + 1);
    return SPIMaster_TransferSequentialAsyncGlob(handle, handle->glob,
                                                 handle->globCount, callback,
                                                 callbackUser, userData);
}

int32_t SPIMaster_TransferSequentialAsync(
    SPIMaster   *handle,
    SPITransfer *transfer,
    uint32_t     count,
    void        (*callback)(int32_t status, uintptr_t data_count))
{
    if (!handle) {
        return ERROR_PARAMETER;
    }

    if (handle->callback) {
        return ERROR_BUSY;
    }

    return SPIMaster_TransferSequentialAsync_Wrapper(
        handle, transfer, count, callback, NULL, NULL);
}

int32_t SPIMaster_TransferSequentialAsync_UserData(
    SPIMaster   *handle,
    SPITransfer *transfer,
    uint32_t     count,
    void        (*callback)(
        int32_t status, uintptr_t data_count, void *userData),
    void        *userData)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }

    if (handle->callback) {
        return ERROR_BUSY;
    }

    return SPIMaster_TransferSequentialAsync_Wrapper(
        handle, transfer, count, NULL, callback, userData);
}

int32_t SPIMaster_TransferCancel(SPIMaster *handle)
{
    if (!handle) {
        return ERROR_PARAMETER;
    }

    // Stop DMA, reset spi_master_start and read spi_scrc (to clear it)
    mt3620_spi_dma_cfg_t *cfg = &SPIMaster_DmaConfig[handle->id];
    MT3620_DMA_FIELD_WRITE(MT3620_SPI_DMA_TX(handle->id), start, str, false);
    cfg->stcsr.spi_master_start = false;
    uint32_t dummy_read = mt3620_spi[handle->id]->scsr;
    (void)dummy_read;

    handle->globCount       = 0;
    handle->globTransferred = 0;

    if (handle->callback) {
        handle->callback(ERROR_SPI_TRANSFER_CANCEL, 0);
        handle->callback = NULL;
    } else if (handle->callbackUser) {
        handle->callbackUser(ERROR_SPI_TRANSFER_CANCEL, 0, handle->userData);
        handle->callbackUser = NULL;
    }

    int32_t status = ERROR_NONE;
    if (handle->csEnable && handle->csCallback) {
        handle->csCallback(handle, false);
    }

    return status;
}

static volatile bool SPIMaster_TransferSequentialSync_Ready = false;
static int32_t       SPIMaster_TransferSequentialSync_Status;
static int32_t       SPIMaster_TransferSequentialSync_Count;

static void SPIMaster_TransferSequentialSync_Callback(int32_t status, uintptr_t data_count)
{
    SPIMaster_TransferSequentialSync_Status = status;
    SPIMaster_TransferSequentialSync_Count  = data_count;
    SPIMaster_TransferSequentialSync_Ready  = true;
}

int32_t SPIMaster_TransferSequentialSync(SPIMaster *handle, SPITransfer *transfer, uint32_t count)
{
    SPIMaster_TransferSequentialSync_Ready = false;
    int32_t status = SPIMaster_TransferSequentialAsync(
        handle, transfer, count, SPIMaster_TransferSequentialSync_Callback);
    if (status != ERROR_NONE) {
        return status;
    }

    while (!SPIMaster_TransferSequentialSync_Ready) {
        __asm__("wfi");
    }

    return SPIMaster_TransferSequentialSync_Status;
}

static void SPIMaster_IRQ(Platform_Unit unit)
{
    unsigned id = SPIMaster_UnitToID(unit);
    if (id >= MT3620_SPI_COUNT) {
        return;
    }

    SPIMaster *handle = &spiContext[id];

    // This should never happen
    if (!handle->open) {
        return;
    }

    if (handle->dma) {
        MT3620_DMA_FIELD_WRITE(MT3620_SPI_DMA_TX(id), start, str, false);
    }

    int32_t status = ERROR_NONE;

    // Clear interrupt flag and the status of the SPI transaction.
    if (!MT3620_SPI_FIELD_READ(id, scsr, spi_ok)) {
        status = ERROR_SPI_TRANSFER_FAIL;
    } else {
        SPIMaster_TransferGlob *glob = &handle->glob[handle->globTransferred];
        if (handle->dma && (mt3620_dma[MT3620_SPI_DMA_TX(id)].rlct != 0)){
            status = ERROR_SPI_TRANSFER_FAIL;
        } else {
            handle->dataCount += (glob->opcodeLen + glob->payloadLen);
        }
    }

    bool final = (status != ERROR_NONE);
    if (status == ERROR_NONE) {
        unsigned g;
        for (g = 0; g < handle->globCount; g++) {
            SPIMaster_TransferGlob *glob = &handle->glob[g];

            unsigned offset = 0;
            unsigned t;
            for (t = 0; t < glob->transferCount; t++) {
                const SPITransfer *transfer = &glob->transfer[t];

                if (transfer->readData) {
                    uint8_t *sdir = (uint8_t*)mt3620_spi[handle->id]->sdir;
                    __builtin_memcpy(transfer->readData, &sdir[offset], transfer->length);
                }

                offset += transfer->length;
                if (t == 0) {
                    offset -= glob->opcodeLen;
                }
            }
        }

        handle->globTransferred++;
        final = (handle->globTransferred >= handle->globCount);
        if (!final) {
            status = SPIMaster_TransferGlobQueue(
                handle, &handle->glob[handle->globTransferred]);
            final = (status != ERROR_NONE);
        }
    }

    if (final) {
        if (handle->csEnable && handle->csCallback) {
            handle->csCallback(handle, false);
        }
        if (handle->callback) {
            handle->callback(status, handle->dataCount);
            handle->callback = NULL;
        } else if (handle->callbackUser) {
            handle->callbackUser(status, handle->dataCount, handle->userData);
            handle->callbackUser = NULL;
        }
    }
}

void isu_g0_spim_irq(void) { SPIMaster_IRQ(MT3620_UNIT_ISU0); }
void isu_g1_spim_irq(void) { SPIMaster_IRQ(MT3620_UNIT_ISU1); }
void isu_g2_spim_irq(void) { SPIMaster_IRQ(MT3620_UNIT_ISU2); }
void isu_g3_spim_irq(void) { SPIMaster_IRQ(MT3620_UNIT_ISU3); }
void isu_g4_spim_irq(void) { SPIMaster_IRQ(MT3620_UNIT_ISU4); }
void isu_g5_spim_irq(void) { SPIMaster_IRQ(MT3620_UNIT_ISU5); }