more refactoring, verified CDC on macOS

src/machine/machine_atsamd51.go

@@ -13,7 +13,6 @@ import (
 	"device/sam"
 	"errors"
 	"runtime/interrupt"
-	"runtime/volatile"
 	"unsafe"
 )
 
@@ -1975,719 +1974,10 @@ func (tcc *TCC) Set(channel uint8, value uint32) {
 	}
 }
 
-// USBCDC is the USB CDC aka serial over USB interface on the SAMD21.
+func InitUSBIO() {
-type USBCDC struct {
+	// Configure USB D+/D- pins.
-	Buffer            *RingBuffer
-	TxIdx             volatile.Register8
-	waitTxc           bool
-	waitTxcRetryCount uint8
-	sent              bool
-	configured        bool
-}
-
-// var (
-// 	// USB is a USB CDC interface.
-// 	USB = &USBCDC{Buffer: NewRingBuffer()}
-// )
-
-const (
-	usbcdcTxSizeMask          uint8 = 0x3F
-	usbcdcTxBankMask          uint8 = ^usbcdcTxSizeMask
-	usbcdcTxBank1st           uint8 = 0x00
-	usbcdcTxBank2nd           uint8 = usbcdcTxSizeMask + 1
-	usbcdcTxMaxRetriesAllowed uint8 = 5
-)
-
-// Flush flushes buffered data.
-func (usbcdc *USBCDC) Flush() error {
-	if usbLineInfo.lineState > 0 {
-		idx := usbcdc.TxIdx.Get()
-		sz := idx & usbcdcTxSizeMask
-		bk := idx & usbcdcTxBankMask
-		if 0 < sz {
-
-			if usbcdc.waitTxc {
-				// waiting for the next flush(), because the transmission is not complete
-				usbcdc.waitTxcRetryCount++
-				return nil
-			}
-			usbcdc.waitTxc = true
-			usbcdc.waitTxcRetryCount = 0
-
-			// set the data
-			usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[usb_CDC_ENDPOINT_IN][bk]))))
-			if bk == usbcdcTxBank1st {
-				usbcdc.TxIdx.Set(usbcdcTxBank2nd)
-			} else {
-				usbcdc.TxIdx.Set(usbcdcTxBank1st)
-			}
-
-			// clean multi packet size of bytes already sent
-			usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
-
-			// set count of bytes to be sent
-			usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-			usbEndpointDescriptors[usb_CDC_ENDPOINT_IN].DeviceDescBank[1].PCKSIZE.SetBits((uint32(sz) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-
-			// clear transfer complete flag
-			setEPINTFLAG(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
-
-			// send data by setting bank ready
-			setEPSTATUSSET(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK1RDY)
-			usbcdc.sent = true
-		}
-	}
-	return nil
-}
-
-// WriteByte writes a byte of data to the USB CDC interface.
-func (usbcdc *USBCDC) WriteByte(c byte) error {
-	// Supposedly to handle problem with Windows USB serial ports?
-	if usbLineInfo.lineState > 0 {
-		ok := false
-		for {
-			mask := interrupt.Disable()
-
-			idx := usbcdc.TxIdx.Get()
-			if (idx & usbcdcTxSizeMask) < usbcdcTxSizeMask {
-				udd_ep_in_cache_buffer[usb_CDC_ENDPOINT_IN][idx] = c
-				usbcdc.TxIdx.Set(idx + 1)
-				ok = true
-			}
-
-			interrupt.Restore(mask)
-
-			if ok {
-				break
-			} else if usbcdcTxMaxRetriesAllowed < usbcdc.waitTxcRetryCount {
-				mask := interrupt.Disable()
-				usbcdc.waitTxc = false
-				usbcdc.waitTxcRetryCount = 0
-				usbcdc.TxIdx.Set(0)
-				usbLineInfo.lineState = 0
-				interrupt.Restore(mask)
-				break
-			} else {
-				mask := interrupt.Disable()
-				if usbcdc.sent {
-					if usbcdc.waitTxc {
-						if (getEPINTFLAG(usb_CDC_ENDPOINT_IN) & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) != 0 {
-							setEPSTATUSCLR(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK1RDY)
-							setEPINTFLAG(usb_CDC_ENDPOINT_IN, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
-							usbcdc.waitTxc = false
-							usbcdc.Flush()
-						}
-					} else {
-						usbcdc.Flush()
-					}
-				}
-				interrupt.Restore(mask)
-			}
-		}
-	}
-
-	return nil
-}
-
-func (usbcdc *USBCDC) DTR() bool {
-	return (usbLineInfo.lineState & usb_CDC_LINESTATE_DTR) > 0
-}
-
-func (usbcdc *USBCDC) RTS() bool {
-	return (usbLineInfo.lineState & usb_CDC_LINESTATE_RTS) > 0
-}
-
-const (
-	// these are SAMD51 specific.
-	usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos  = 0
-	usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask = 0x3FFF
-
-	usb_DEVICE_PCKSIZE_SIZE_Pos  = 28
-	usb_DEVICE_PCKSIZE_SIZE_Mask = 0x7
-
-	usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos  = 14
-	usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask = 0x3FFF
-)
-
-var (
-	usbEndpointDescriptors [8]usbDeviceDescriptor
-
-	udd_ep_in_cache_buffer  [7][128]uint8
-	udd_ep_out_cache_buffer [7][128]uint8
-
-	isEndpointHalt        = false
-	isRemoteWakeUpEnabled = false
-	endPoints             = []uint32{usb_ENDPOINT_TYPE_CONTROL,
-		(usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointIn),
-		(usb_ENDPOINT_TYPE_BULK | usbEndpointOut),
-		(usb_ENDPOINT_TYPE_BULK | usbEndpointIn)}
-
-	usbConfiguration uint8
-	usbSetInterface  uint8
-	usbLineInfo      = cdcLineInfo{115200, 0x00, 0x00, 0x08, 0x00}
-)
-
-// Configure the USB CDC interface. The config is here for compatibility with the UART interface.
-func (usbcdc *USBCDC) Configure(config UARTConfig) {
-	// reset USB interface
-	sam.USB_DEVICE.CTRLA.SetBits(sam.USB_DEVICE_CTRLA_SWRST)
-	for sam.USB_DEVICE.SYNCBUSY.HasBits(sam.USB_DEVICE_SYNCBUSY_SWRST) ||
-		sam.USB_DEVICE.SYNCBUSY.HasBits(sam.USB_DEVICE_SYNCBUSY_ENABLE) {
-	}
-
-	sam.USB_DEVICE.DESCADD.Set(uint32(uintptr(unsafe.Pointer(&usbEndpointDescriptors))))
-
-	// configure pins
 	USBCDC_DM_PIN.Configure(PinConfig{Mode: PinCom})
 	USBCDC_DP_PIN.Configure(PinConfig{Mode: PinCom})
-
-	// performs pad calibration from store fuses
-	handlePadCalibration()
-
-	// run in standby
-	sam.USB_DEVICE.CTRLA.SetBits(sam.USB_DEVICE_CTRLA_RUNSTDBY)
-
-	// set full speed
-	sam.USB_DEVICE.CTRLB.SetBits(sam.USB_DEVICE_CTRLB_SPDCONF_FS << sam.USB_DEVICE_CTRLB_SPDCONF_Pos)
-
-	// attach
-	sam.USB_DEVICE.CTRLB.ClearBits(sam.USB_DEVICE_CTRLB_DETACH)
-
-	// enable interrupt for end of reset
-	sam.USB_DEVICE.INTENSET.SetBits(sam.USB_DEVICE_INTENSET_EORST)
-
-	// enable interrupt for start of frame
-	sam.USB_DEVICE.INTENSET.SetBits(sam.USB_DEVICE_INTENSET_SOF)
-
-	// enable USB
-	sam.USB_DEVICE.CTRLA.SetBits(sam.USB_DEVICE_CTRLA_ENABLE)
-
-	// enable IRQ at highest priority
-	//interrupt.New(sam.IRQ_USB_OTHER, handleUSBIRQ).Enable()
-	//interrupt.New(sam.IRQ_USB_SOF_HSOF, handleUSBIRQ).Enable()
-	//interrupt.New(sam.IRQ_USB_TRCPT0, handleUSBIRQ).Enable()
-	//interrupt.New(sam.IRQ_USB_TRCPT1, handleUSBIRQ).Enable()
-
-	usbcdc.configured = true
-}
-
-// Configured returns whether usbcdc is configured or not.
-func (usbcdc *USBCDC) Configured() bool {
-	return usbcdc.configured
-}
-
-func handlePadCalibration() {
-	// Load Pad Calibration data from non-volatile memory
-	// This requires registers that are not included in the SVD file.
-	// Modeled after defines from samd21g18a.h and nvmctrl.h:
-	//
-	// #define NVMCTRL_OTP4 0x00806020
-	//
-	// #define USB_FUSES_TRANSN_ADDR       (NVMCTRL_OTP4 + 4)
-	// #define USB_FUSES_TRANSN_Pos        13           /**< \brief (NVMCTRL_OTP4) USB pad Transn calibration */
-	// #define USB_FUSES_TRANSN_Msk        (0x1Fu << USB_FUSES_TRANSN_Pos)
-	// #define USB_FUSES_TRANSN(value)     ((USB_FUSES_TRANSN_Msk & ((value) << USB_FUSES_TRANSN_Pos)))
-
-	// #define USB_FUSES_TRANSP_ADDR       (NVMCTRL_OTP4 + 4)
-	// #define USB_FUSES_TRANSP_Pos        18           /**< \brief (NVMCTRL_OTP4) USB pad Transp calibration */
-	// #define USB_FUSES_TRANSP_Msk        (0x1Fu << USB_FUSES_TRANSP_Pos)
-	// #define USB_FUSES_TRANSP(value)     ((USB_FUSES_TRANSP_Msk & ((value) << USB_FUSES_TRANSP_Pos)))
-
-	// #define USB_FUSES_TRIM_ADDR         (NVMCTRL_OTP4 + 4)
-	// #define USB_FUSES_TRIM_Pos          23           /**< \brief (NVMCTRL_OTP4) USB pad Trim calibration */
-	// #define USB_FUSES_TRIM_Msk          (0x7u << USB_FUSES_TRIM_Pos)
-	// #define USB_FUSES_TRIM(value)       ((USB_FUSES_TRIM_Msk & ((value) << USB_FUSES_TRIM_Pos)))
-	//
-	fuse := *(*uint32)(unsafe.Pointer(uintptr(0x00806020) + 4))
-	calibTransN := uint16(fuse>>13) & uint16(0x1f)
-	calibTransP := uint16(fuse>>18) & uint16(0x1f)
-	calibTrim := uint16(fuse>>23) & uint16(0x7)
-
-	if calibTransN == 0x1f {
-		calibTransN = 5
-	}
-	sam.USB_DEVICE.PADCAL.SetBits(calibTransN << sam.USB_DEVICE_PADCAL_TRANSN_Pos)
-
-	if calibTransP == 0x1f {
-		calibTransP = 29
-	}
-	sam.USB_DEVICE.PADCAL.SetBits(calibTransP << sam.USB_DEVICE_PADCAL_TRANSP_Pos)
-
-	if calibTrim == 0x7 {
-		calibTrim = 3
-	}
-	sam.USB_DEVICE.PADCAL.SetBits(calibTrim << sam.USB_DEVICE_PADCAL_TRIM_Pos)
-}
-
-func handleUSBIRQ(interrupt.Interrupt) {
-	// reset all interrupt flags
-	flags := sam.USB_DEVICE.INTFLAG.Get()
-	sam.USB_DEVICE.INTFLAG.Set(flags)
-
-	// End of reset
-	if (flags & sam.USB_DEVICE_INTFLAG_EORST) > 0 {
-		// Configure control endpoint
-		initEndpoint(0, usb_ENDPOINT_TYPE_CONTROL)
-
-		// Enable Setup-Received interrupt
-		setEPINTENSET(0, sam.USB_DEVICE_ENDPOINT_EPINTENSET_RXSTP)
-
-		usbConfiguration = 0
-
-		// ack the End-Of-Reset interrupt
-		sam.USB_DEVICE.INTFLAG.Set(sam.USB_DEVICE_INTFLAG_EORST)
-	}
-
-	// Start of frame
-	if (flags & sam.USB_DEVICE_INTFLAG_SOF) > 0 {
-		//USB.Flush()
-		// if you want to blink LED showing traffic, this would be the place...
-	}
-
-	// Endpoint 0 Setup interrupt
-	if getEPINTFLAG(0)&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_RXSTP > 0 {
-		// ack setup received
-		setEPINTFLAG(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_RXSTP)
-
-		// parse setup
-		setup := newUSBSetup(udd_ep_out_cache_buffer[0][:])
-
-		// Clear the Bank 0 ready flag on Control OUT
-		setEPSTATUSCLR(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
-		usbEndpointDescriptors[0].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-
-		ok := false
-		if (setup.bmRequestType & usb_REQUEST_TYPE) == usb_REQUEST_STANDARD {
-			// Standard Requests
-			ok = handleStandardSetup(setup)
-		} else {
-			// Class Interface Requests
-			if setup.wIndex == usb_CDC_ACM_INTERFACE {
-				ok = cdcSetup(setup)
-			}
-		}
-
-		if ok {
-			// set Bank1 ready
-			setEPSTATUSSET(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK1RDY)
-		} else {
-			// Stall endpoint
-			setEPSTATUSSET(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_STALL1)
-		}
-
-		if getEPINTFLAG(0)&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_STALL1 > 0 {
-			// ack the stall
-			setEPINTFLAG(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_STALL1)
-
-			// clear stall request
-			setEPINTENCLR(0, sam.USB_DEVICE_ENDPOINT_EPINTENCLR_STALL1)
-		}
-	}
-
-	// Now the actual transfer handlers, ignore endpoint number 0 (setup)
-	var i uint32
-	for i = 1; i < uint32(len(endPoints)); i++ {
-		// Check if endpoint has a pending interrupt
-		epFlags := getEPINTFLAG(i)
-		if (epFlags&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT0) > 0 ||
-			(epFlags&sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) > 0 {
-			switch i {
-			case usb_CDC_ENDPOINT_OUT:
-				handleEndpoint(i)
-				setEPINTFLAG(i, epFlags)
-			case usb_CDC_ENDPOINT_IN, usb_CDC_ENDPOINT_ACM:
-				setEPSTATUSCLR(i, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK1RDY)
-				setEPINTFLAG(i, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
-
-				if i == usb_CDC_ENDPOINT_IN {
-					//USB.waitTxc = false
-				}
-			}
-		}
-	}
-}
-
-func initEndpoint(ep, config uint32) {
-	switch config {
-	case usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointIn:
-		// set packet size
-		usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
-
-		// set data buffer address
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
-
-		// set endpoint type
-		setEPCFG(ep, ((usb_ENDPOINT_TYPE_INTERRUPT + 1) << sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE1_Pos))
-
-	case usb_ENDPOINT_TYPE_BULK | usbEndpointOut:
-		// set packet size
-		usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
-
-		// set data buffer address
-		usbEndpointDescriptors[ep].DeviceDescBank[0].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_out_cache_buffer[ep]))))
-
-		// set endpoint type
-		setEPCFG(ep, ((usb_ENDPOINT_TYPE_BULK + 1) << sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE0_Pos))
-
-		// receive interrupts when current transfer complete
-		setEPINTENSET(ep, sam.USB_DEVICE_ENDPOINT_EPINTENSET_TRCPT0)
-
-		// set byte count to zero, we have not received anything yet
-		usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-
-		// ready for next transfer
-		setEPSTATUSCLR(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
-
-	case usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointOut:
-		// TODO: not really anything, seems like...
-
-	case usb_ENDPOINT_TYPE_BULK | usbEndpointIn:
-		// set packet size
-		usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
-
-		// set data buffer address
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
-
-		// set endpoint type
-		setEPCFG(ep, ((usb_ENDPOINT_TYPE_BULK + 1) << sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE1_Pos))
-
-		// NAK on endpoint IN, the bank is not yet filled in.
-		setEPSTATUSCLR(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK1RDY)
-
-	case usb_ENDPOINT_TYPE_CONTROL:
-		// Control OUT
-		// set packet size
-		usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
-
-		// set data buffer address
-		usbEndpointDescriptors[ep].DeviceDescBank[0].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_out_cache_buffer[ep]))))
-
-		// set endpoint type
-		setEPCFG(ep, getEPCFG(ep)|((usb_ENDPOINT_TYPE_CONTROL+1)<<sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE0_Pos))
-
-		// Control IN
-		// set packet size
-		usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos)
-
-		// set data buffer address
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
-
-		// set endpoint type
-		setEPCFG(ep, getEPCFG(ep)|((usb_ENDPOINT_TYPE_CONTROL+1)<<sam.USB_DEVICE_ENDPOINT_EPCFG_EPTYPE1_Pos))
-
-		// Prepare OUT endpoint for receive
-		// set multi packet size for expected number of receive bytes on control OUT
-		usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(64 << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
-
-		// set byte count to zero, we have not received anything yet
-		usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-
-		// NAK on endpoint OUT to show we are ready to receive control data
-		setEPSTATUSSET(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK0RDY)
-	}
-}
-
-func handleStandardSetup(setup usbSetup) bool {
-	switch setup.bRequest {
-	case usb_GET_STATUS:
-		buf := []byte{0, 0}
-
-		if setup.bmRequestType != 0 { // endpoint
-			// TODO: actually check if the endpoint in question is currently halted
-			if isEndpointHalt {
-				buf[0] = 1
-			}
-		}
-
-		sendUSBPacket(0, buf)
-		return true
-
-	case usb_CLEAR_FEATURE:
-		if setup.wValueL == 1 { // DEVICEREMOTEWAKEUP
-			isRemoteWakeUpEnabled = false
-		} else if setup.wValueL == 0 { // ENDPOINTHALT
-			isEndpointHalt = false
-		}
-		sendZlp()
-		return true
-
-	case usb_SET_FEATURE:
-		if setup.wValueL == 1 { // DEVICEREMOTEWAKEUP
-			isRemoteWakeUpEnabled = true
-		} else if setup.wValueL == 0 { // ENDPOINTHALT
-			isEndpointHalt = true
-		}
-		sendZlp()
-		return true
-
-	case usb_SET_ADDRESS:
-		// set packet size 64 with auto Zlp after transfer
-		usbEndpointDescriptors[0].DeviceDescBank[1].PCKSIZE.Set((epPacketSize(64) << usb_DEVICE_PCKSIZE_SIZE_Pos) |
-			uint32(1<<31)) // autozlp
-
-		// ack the transfer is complete from the request
-		setEPINTFLAG(0, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
-
-		// set bank ready for data
-		setEPSTATUSSET(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSSET_BK1RDY)
-
-		// wait for transfer to complete
-		timeout := 3000
-		for (getEPINTFLAG(0) & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) == 0 {
-			timeout--
-			if timeout == 0 {
-				return true
-			}
-		}
-
-		// last, set the device address to that requested by host
-		sam.USB_DEVICE.DADD.SetBits(setup.wValueL)
-		sam.USB_DEVICE.DADD.SetBits(sam.USB_DEVICE_DADD_ADDEN)
-
-		return true
-
-	case usb_GET_DESCRIPTOR:
-		sendDescriptor(setup)
-		return true
-
-	case usb_SET_DESCRIPTOR:
-		return false
-
-	case usb_GET_CONFIGURATION:
-		buff := []byte{usbConfiguration}
-		sendUSBPacket(0, buff)
-		return true
-
-	case usb_SET_CONFIGURATION:
-		if setup.bmRequestType&usb_REQUEST_RECIPIENT == usb_REQUEST_DEVICE {
-			for i := 1; i < len(endPoints); i++ {
-				initEndpoint(uint32(i), endPoints[i])
-			}
-
-			usbConfiguration = setup.wValueL
-
-			// Enable interrupt for CDC control messages from host (OUT packet)
-			setEPINTENSET(usb_CDC_ENDPOINT_ACM, sam.USB_DEVICE_ENDPOINT_EPINTENSET_TRCPT1)
-
-			// Enable interrupt for CDC data messages from host
-			setEPINTENSET(usb_CDC_ENDPOINT_OUT, sam.USB_DEVICE_ENDPOINT_EPINTENSET_TRCPT0)
-
-			sendZlp()
-			return true
-		} else {
-			return false
-		}
-
-	case usb_GET_INTERFACE:
-		buff := []byte{usbSetInterface}
-		sendUSBPacket(0, buff)
-		return true
-
-	case usb_SET_INTERFACE:
-		usbSetInterface = setup.wValueL
-
-		sendZlp()
-		return true
-
-	default:
-		return true
-	}
-}
-
-func cdcSetup(setup usbSetup) bool {
-	if setup.bmRequestType == usb_REQUEST_DEVICETOHOST_CLASS_INTERFACE {
-		if setup.bRequest == usb_CDC_GET_LINE_CODING {
-			var b [cdcLineInfoSize]byte
-			b[0] = byte(usbLineInfo.dwDTERate)
-			b[1] = byte(usbLineInfo.dwDTERate >> 8)
-			b[2] = byte(usbLineInfo.dwDTERate >> 16)
-			b[3] = byte(usbLineInfo.dwDTERate >> 24)
-			b[4] = byte(usbLineInfo.bCharFormat)
-			b[5] = byte(usbLineInfo.bParityType)
-			b[6] = byte(usbLineInfo.bDataBits)
-
-			sendUSBPacket(0, b[:])
-			return true
-		}
-	}
-
-	if setup.bmRequestType == usb_REQUEST_HOSTTODEVICE_CLASS_INTERFACE {
-		if setup.bRequest == usb_CDC_SET_LINE_CODING {
-			b, err := receiveUSBControlPacket()
-			if err != nil {
-				return false
-			}
-
-			usbLineInfo.dwDTERate = uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
-			usbLineInfo.bCharFormat = b[4]
-			usbLineInfo.bParityType = b[5]
-			usbLineInfo.bDataBits = b[6]
-		}
-
-		if setup.bRequest == usb_CDC_SET_CONTROL_LINE_STATE {
-			usbLineInfo.lineState = setup.wValueL
-		}
-
-		if setup.bRequest == usb_CDC_SET_LINE_CODING || setup.bRequest == usb_CDC_SET_CONTROL_LINE_STATE {
-			// auto-reset into the bootloader
-			if usbLineInfo.dwDTERate == 1200 && usbLineInfo.lineState&usb_CDC_LINESTATE_DTR == 0 {
-				ResetProcessor()
-			} else {
-				// TODO: cancel any reset
-			}
-			sendZlp()
-		}
-
-		if setup.bRequest == usb_CDC_SEND_BREAK {
-			// TODO: something with this value?
-			// breakValue = ((uint16_t)setup.wValueH << 8) | setup.wValueL;
-			// return false;
-			sendZlp()
-		}
-		return true
-	}
-	return false
-}
-
-//go:noinline
-func sendUSBPacket(ep uint32, data []byte) {
-	copy(udd_ep_in_cache_buffer[ep][:], data)
-
-	// Set endpoint address for sending data
-	usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
-
-	// clear multi-packet size which is total bytes already sent
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
-
-	// set byte count, which is total number of bytes to be sent
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits(uint32((len(data) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos))
-}
-
-func receiveUSBControlPacket() ([cdcLineInfoSize]byte, error) {
-	var b [cdcLineInfoSize]byte
-
-	// address
-	usbEndpointDescriptors[0].DeviceDescBank[0].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_out_cache_buffer[0]))))
-
-	// set byte count to zero
-	usbEndpointDescriptors[0].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-
-	// set ready for next data
-	setEPSTATUSCLR(0, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
-
-	// Wait until OUT transfer is ready.
-	timeout := 300000
-	for (getEPSTATUS(0) & sam.USB_DEVICE_ENDPOINT_EPSTATUS_BK0RDY) == 0 {
-		timeout--
-		if timeout == 0 {
-			return b, errUSBCDCReadTimeout
-		}
-	}
-
-	// Wait until OUT transfer is completed.
-	timeout = 300000
-	for (getEPINTFLAG(0) & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) == 0 {
-		timeout--
-		if timeout == 0 {
-			return b, errUSBCDCReadTimeout
-		}
-	}
-
-	// get data
-	bytesread := uint32((usbEndpointDescriptors[0].DeviceDescBank[0].PCKSIZE.Get() >>
-		usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask)
-
-	if bytesread != cdcLineInfoSize {
-		return b, errUSBCDCBytesRead
-	}
-
-	copy(b[:7], udd_ep_out_cache_buffer[0][:7])
-
-	return b, nil
-}
-
-func handleEndpoint(ep uint32) {
-	// get data
-	count := int((usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.Get() >>
-		usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask)
-
-	// move to ring buffer
-	for i := 0; i < count; i++ {
-		//USB.Receive(byte((udd_ep_out_cache_buffer[ep][i] & 0xFF)))
-	}
-
-	// set byte count to zero
-	usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-
-	// set multi packet size to 64
-	usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.SetBits(64 << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
-
-	// set ready for next data
-	setEPSTATUSCLR(ep, sam.USB_DEVICE_ENDPOINT_EPSTATUSCLR_BK0RDY)
-}
-
-func sendZlp() {
-	usbEndpointDescriptors[0].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-}
-
-func epPacketSize(size uint16) uint32 {
-	switch size {
-	case 8:
-		return 0
-	case 16:
-		return 1
-	case 32:
-		return 2
-	case 64:
-		return 3
-	case 128:
-		return 4
-	case 256:
-		return 5
-	case 512:
-		return 6
-	case 1023:
-		return 7
-	default:
-		return 0
-	}
-}
-
-func getEPCFG(ep uint32) uint8 {
-	return sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPCFG.Get()
-}
-
-func setEPCFG(ep uint32, val uint8) {
-	sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPCFG.Set(val)
-}
-
-func setEPSTATUSCLR(ep uint32, val uint8) {
-	sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPSTATUSCLR.Set(val)
-}
-
-func setEPSTATUSSET(ep uint32, val uint8) {
-	sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPSTATUSSET.Set(val)
-}
-
-func getEPSTATUS(ep uint32) uint8 {
-	return sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPSTATUS.Get()
-}
-
-func getEPINTFLAG(ep uint32) uint8 {
-	return sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTFLAG.Get()
-}
-
-func setEPINTFLAG(ep uint32, val uint8) {
-	sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTFLAG.Set(val)
-}
-
-func setEPINTENCLR(ep uint32, val uint8) {
-	sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTENCLR.Set(val)
-}
-
-func setEPINTENSET(ep uint32, val uint8) {
-	sam.USB_DEVICE.DEVICE_ENDPOINT[ep].EPINTENSET.Set(val)
 }
 
 // ResetProcessor should perform a system reset in preparation

src/machine/usb-cdc.go

@@ -1,14 +1,14 @@
-//go:build baremetal && usb.cdc
+//go:build usb.cdc
-// +build baremetal,usb.cdc
+// +build usb.cdc
 
 package machine
 
 import "machine/usb"
 
-var USB = &usb.CDC{Port: 0}
+var USB = &usb.CDC{}
 
-func init() {
+func InitUSB(port int) {
-	// Configure USB D+/D- pins.
+	InitUSBIO()
-	USBCDC_DM_PIN.Configure(PinConfig{Mode: PinCom})
+	USB.Port = port
-	USBCDC_DP_PIN.Configure(PinConfig{Mode: PinCom})
+	USB.Configure(usb.CDCConfig{})
 }

src/machine/usb-hid.go

@@ -1,14 +1,14 @@
-//go:build baremetal && usb.hid
+//go:build usb.hid
-// +build baremetal,usb.hid
+// +build usb.hid
 
 package machine
 
 import "machine/usb"
 
-var USB = &usb.HID{Port: 0}
+var USB = &usb.HID{}
 
-func init() {
+func InitUSB(port int) {
-	// Configure USB D+/D- pins.
+	InitUSBIO()
-	USBCDC_DM_PIN.Configure(PinConfig{Mode: PinCom})
+	USB.Port = port
-	USBCDC_DP_PIN.Configure(PinConfig{Mode: PinCom})
+	USB.Configure(usb.HIDConfig{})
 }

src/machine/usb.go

@@ -1,5 +1,5 @@
-//go:build sam || nrf52840
+//go:build nrf52840
-// +build sam nrf52840
+// +build nrf52840
 
 package machine
 

src/machine/usb/dcd-cdc.go

@@ -1,5 +1,5 @@
-//go:build baremetal && usb.cdc
+//go:build usb.cdc
-// +build baremetal,usb.cdc
+// +build usb.cdc
 
 package usb
 

src/machine/usb/dcd-hid.go

@@ -1,5 +1,5 @@
-//go:build baremetal && usb.hid
+//go:build usb.hid
-// +build baremetal,usb.hid
+// +build usb.hid
 
 package usb
 

src/machine/usb/desc-cdc.go

@@ -1,8 +1,12 @@
-//go:build baremetal && usb.cdc
+//go:build usb.cdc
-// +build baremetal,usb.cdc
+// +build usb.cdc
 
 package usb
 
+// descHIDCount defines the number of USB cores that may be configured as a
+// composite (keyboard + mouse + joystick) human interface device (HID).
+const descHIDCount = 0
+
 // USB CDC constants defined per specification.
 const (
 
@@ -291,7 +295,7 @@ var descCDC = [dcdCount]descCDCClass{
 			1,                         // Index of string descriptor describing manufacturer
 			2,                         // Index of string descriptor describing product
 			3,                         // Index of string descriptor describing the device's serial number
-			descCDCACMCount,           // Number of possible configurations
+			descCDCCount,              // Number of possible configurations
 		},
 		qualif: &[descLengthQualification]uint8{
 			descLengthQualification,  // Size of this descriptor in bytes
@@ -302,7 +306,7 @@ var descCDC = [dcdCount]descCDCClass{
 			0,                        // Subclass code (assigned by the USB-IF).
 			0,                        // Protocol code (assigned by the USB-IF).
 			descEndptMaxPktSize,      // Maximum packet size for endpoint zero (8, 16, 32, or 64)
-			descCDCACMCount,          // Number of possible configurations
+			descCDCCount,             // Number of possible configurations
 			0,                        // Reserved
 		},
 		config: &[descCDCConfigSize]uint8{

src/machine/usb/desc-cdc_atsamd51.go

@@ -1,5 +1,4 @@
-//go:build baremetal && usb.cdc && (atsamd51 || atsame5x)
+//go:build usb.cdc && (atsamd51 || atsame5x)
-// +build baremetal
 // +build usb.cdc
 // +build atsamd51 atsame5x
 
@@ -7,6 +6,10 @@ package usb
 
 import "runtime/volatile"
 
+// descCDCCount defines the number of USB cores that may be configured as
+// CDC-ACM (single) devices.
+const descCDCCount = 1
+
 // Constants for USB CDC-ACM device classes.
 const (
 

src/machine/usb/desc-hid.go

@@ -1,8 +1,12 @@
-//go:build baremetal && usb.hid
+//go:build usb.hid
-// +build baremetal,usb.hid
+// +build usb.hid
 
 package usb
 
+// descCDCCount defines the number of USB cores that may be configured as
+// CDC-ACM (single) devices.
+const descCDCCount = 0
+
 // USB HID constants defined per specification
 const (
 	// HID class

src/machine/usb/desc-hid_atsamd51.go

@@ -1,10 +1,13 @@
-//go:build baremetal && usb.hid && (atsamd51 || atsame5x)
+//go:build usb.hid && (atsamd51 || atsame5x)
-// +build baremetal
 // +build usb.hid
 // +build atsamd51 atsame5x
 
 package usb
 
+// descHIDCount defines the number of USB cores that may be configured as a
+// composite (keyboard + mouse + joystick) human interface device (HID).
+const descHIDCount = 1
+
 // Constants for USB HID (keyboard, mouse, joystick) device classes.
 const (
 

src/machine/usb/desc_atsamd51.go

@@ -1,5 +1,5 @@
-//go:build (sam && atsamd51) || (sam && atsame5x)
+//go:build atsamd51 || atsame5x
-// +build sam,atsamd51 sam,atsame5x
+// +build atsamd51 atsame5x
 
 package usb
 
@@ -11,14 +11,6 @@ const descCPUFrequencyHz = 120000000
 // host/device controller instances.
 const descCoreCount = 1 // SAMx51 has a single, full-speed USB PHY
 
-// descCDCCount defines the number of USB cores that may be configured as
-// CDC-ACM (single) devices.
-const descCDCCount = 0
-
-// descHIDCount defines the number of USB cores that may be configured as a
-// composite (keyboard + mouse + joystick) human interface device (HID).
-const descHIDCount = 1
-
 // General USB device identification constants.
 const (
 	descCommonVendorID  = 0x03EB

src/machine/usb/dhw-cdc_atsamd51.go

@@ -1,5 +1,4 @@
-//go:build baremetal && usb.cdc && (atsamd51 || atsame5x)
+//go:build usb.cdc && (atsamd51 || atsame5x)
-// +build baremetal
 // +build usb.cdc
 // +build atsamd51 atsame5x
 

src/machine/usb/dhw-hid_atsamd51.go

@@ -1,5 +1,4 @@
-//go:build baremetal && usb.hid && (atsamd51 || atsame5x)
+//go:build usb.hid && (atsamd51 || atsame5x)
-// +build baremetal
 // +build usb.hid
 // +build atsamd51 atsame5x
 

src/machine/usb/dhw_atsamd51.go

@@ -1,5 +1,5 @@
-//go:build (sam && atsamd51) || (sam && atsame5x)
+//go:build atsamd51 || atsame5x
-// +build sam,atsamd51 sam,atsame5x
+// +build atsamd51 atsame5x
 
 package usb
 

src/machine/usb/hhw_atsamd51.go

@@ -1,5 +1,5 @@
-//go:build (sam && atsamd51) || (sam && atsame5x)
+//go:build atsamd51 || atsame5x
-// +build sam,atsamd51 sam,atsame5x
+// +build atsamd51 atsame5x
 
 package usb
 

src/machine/usb/usb-cdc.go

@@ -1,5 +1,5 @@
-//go:build baremetal && usb.cdc
+//go:build usb.cdc
-// +build baremetal,usb.cdc
+// +build usb.cdc
 
 package usb
 

src/machine/usb/usb-hid-keyboard.go

@@ -1,5 +1,5 @@
-//go:build baremetal && usb.hid
+//go:build usb.hid
-// +build baremetal,usb.hid
+// +build usb.hid
 
 package usb
 

src/machine/usb/usb-hid.go

@@ -1,5 +1,5 @@
-//go:build baremetal && usb.hid
+//go:build usb.hid
-// +build baremetal,usb.hid
+// +build usb.hid
 
 package usb
 

src/runtime/runtime_atsamd51.go

@@ -33,7 +33,7 @@ func init() {
 	//	machine.USB.Configure(usb.UARTConfig{})
 	//}
 
-	initUSB()
+	machine.InitUSB(0)
 }
 
 func putchar(c byte) {

src/runtime/usb-cdc.go

@@ -1,14 +0,0 @@
-//go:build baremetal && usb.cdc
-// +build baremetal,usb.cdc
-
-package runtime
-
-import (
-	"machine"
-	"machine/usb"
-)
-
-func initUSB() {
-	// Configure CDC interface.
-	machine.USB.Configure(usb.CDCConfig{})
-}

src/runtime/usb-hid.go

@@ -1,14 +0,0 @@
-//go:build baremetal && usb.hid
-// +build baremetal,usb.hid
-
-package runtime
-
-import (
-	"machine"
-	"machine/usb"
-)
-
-func initUSB() {
-	// Configure HID interface.
-	machine.USB.Configure(usb.HIDConfig{})
-}