dspico-usb-examples/platform/DSPicoUsbInEndpoint.cpp

#include "common.h"
#include "libtwl/dma/dmaNitro.h"
#include "tusb.h"
#include "device/dcd.h"
#include "DSPicoUsb.h"
#include "DSPicoUsbInEndpoint.h"

void DSPicoUsbInEndpoint::BeginTransfer(const u8* buffer, u32 length)
{
    rtos_lockMutex(&_mutex);
    {
        _buffer = buffer;
        _bufferLength = length;
        _remaining = length;
        _bufferOffset = 0;
        _currentDSPicoBuffer = 0;
        _transferActive = true;
        SendUsbBlock(true);
        SendUsbBlock(false);
    }
    rtos_unlockMutex(&_mutex);
}

void DSPicoUsbInEndpoint::ProcessTransferCompleteEvent(u32 transferredBytes)
{
    rtos_lockMutex(&_mutex);
    {
        if (_transferActive)
        {
            _remaining -= transferredBytes;
            if (_remaining == 0)
            {
                dcd_event_xfer_complete(0, _endpointAddress, _bufferLength, XFER_RESULT_SUCCESS, true);
                _transferActive = false;
            }
            else
            {
                u32 length = _remaining;
                if (length > 512)
                {
                    length = 512;
                }
                rtos_lockMutex(&gCardMutex);
                {
                    card_romSetCmd(DSPICO_CMD_USB_COMMAND_BEGIN_TRANSFER(_endpointAddress, 1 - _currentDSPicoBuffer, length));
                    card_romStartXfer(DSPICO_USB_DEFAULT_COMMAND_SETTINGS, false);
                    card_romWaitBusy();
                }
                rtos_unlockMutex(&gCardMutex);

                SendUsbBlock(false);
            }
        }
        else
        {
            // This seems to happen only once on the control endpoint. Idk why.
            dcd_event_xfer_complete(0, _endpointAddress, transferredBytes, XFER_RESULT_SUCCESS, true);
        }
    }
    rtos_unlockMutex(&_mutex);
}

void DSPicoUsbInEndpoint::SendUsbBlock(bool startTransfer)
{
    u32 length = _bufferLength - _bufferOffset;
    if (length > 0)
    {
        if (length > 512)
        {
            length = 512;
        }

        rtos_lockMutex(&gCardMutex);
        {
            REG_DMA3SAD = (u32)(_buffer + _bufferOffset);
            REG_DMA3DAD = (u32)&REG_MCD1;
            REG_DMA3CNT = 0xA6400001;
            card_romSetCmd(DSPICO_CMD_USB_WRITE_DATA(_currentDSPicoBuffer, _endpointAddress, startTransfer, length));
            card_romStartXfer(MCCNT1_DIR_WRITE | MCCNT1_RESET_OFF | MCCNT1_CLK_6_7_MHZ | MCCNT1_LEN_512 | MCCNT1_CMD_SCRAMBLE |
                MCCNT1_LATENCY2(8) | MCCNT1_CLOCK_SCRAMBLER | MCCNT1_READ_DATA_DESCRAMBLE | MCCNT1_LATENCY1(0), false);
            card_romWaitBusy();
            REG_DMA3CNT = 0;
        }
        rtos_unlockMutex(&gCardMutex);

        _bufferOffset += length;
        _currentDSPicoBuffer = 1 - _currentDSPicoBuffer;
    }
    else if (startTransfer)
    {
        // zero length transfer
        rtos_lockMutex(&gCardMutex);
        {
            card_romSetCmd(DSPICO_CMD_USB_WRITE_DATA(_currentDSPicoBuffer, _endpointAddress, true, 0));
            card_romStartXfer(DSPICO_USB_DEFAULT_COMMAND_SETTINGS, false);
            card_romWaitBusy();
        }
        rtos_unlockMutex(&gCardMutex);
    }
}