usb: add USB mass storage class support

GNUmakefile

@@ -792,6 +792,10 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-nrf52840    examples/usb-midi
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pico    			examples/usb-storage
+	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pico2    			examples/usb-storage
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=nrf52840-s140v6-uf2-generic	examples/machinetest
 	@$(MD5SUM) test.hex
 ifneq ($(STM32), 0)

src/examples/usb-storage/main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"machine"
+	"machine/usb/msc"
+	"time"
+)
+
+func main() {
+	msc.Port(machine.Flash)
+
+	for {
+		time.Sleep(2 * time.Second)
+	}
+}

src/machine/machine_atsamd21_usb.go

@@ -19,6 +19,21 @@ const (
 
 	usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos  = 14
 	usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask = 0x3FFF
+
+	NumberOfUSBEndpoints = 8
+)
+
+var (
+	endPoints = []uint32{
+		usb.CONTROL_ENDPOINT:  usb.ENDPOINT_TYPE_CONTROL,
+		usb.CDC_ENDPOINT_ACM:  (usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointIn),
+		usb.CDC_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_BULK | usb.EndpointOut),
+		usb.CDC_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_BULK | usb.EndpointIn),
+		usb.HID_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_DISABLE), // Interrupt In
+		usb.HID_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_DISABLE), // Interrupt Out
+		usb.MIDI_ENDPOINT_IN:  (usb.ENDPOINT_TYPE_DISABLE), // Bulk In
+		usb.MIDI_ENDPOINT_OUT: (usb.ENDPOINT_TYPE_DISABLE), // Bulk Out
+	}
 )
 
 // Configure the USB peripheral. The config is here for compatibility with the UART interface.
@@ -179,10 +194,9 @@ func handleUSBIRQ(intr interrupt.Interrupt) {
 		setEPINTFLAG(i, epFlags)
 		if (epFlags & sam.USB_DEVICE_EPINTFLAG_TRCPT0) > 0 {
 			buf := handleEndpointRx(i)
-			if usbRxHandler[i] != nil {
-				usbRxHandler[i](buf)
+			if usbRxHandler[i] == nil || usbRxHandler[i](buf) {
+				AckUsbOutTransfer(i)
 			}
-			handleEndpointRxComplete(i)
 		} else if (epFlags & sam.USB_DEVICE_EPINTFLAG_TRCPT1) > 0 {
 			if usbTxHandler[i] != nil {
 				usbTxHandler[i]()
@@ -402,7 +416,8 @@ func handleEndpointRx(ep uint32) []byte {
 	return udd_ep_out_cache_buffer[ep][:count]
 }
 
-func handleEndpointRxComplete(ep uint32) {
+// AckUsbOutTransfer is called to acknowledge the completion of a USB OUT transfer.
+func AckUsbOutTransfer(ep uint32) {
 	// set byte count to zero
 	usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
 

src/machine/machine_atsamd51_usb.go

@@ -19,6 +19,21 @@ const (
 
 	usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos  = 14
 	usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask = 0x3FFF
+
+	NumberOfUSBEndpoints = 8
+)
+
+var (
+	endPoints = []uint32{
+		usb.CONTROL_ENDPOINT:  usb.ENDPOINT_TYPE_CONTROL,
+		usb.CDC_ENDPOINT_ACM:  (usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointIn),
+		usb.CDC_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_BULK | usb.EndpointOut),
+		usb.CDC_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_BULK | usb.EndpointIn),
+		usb.HID_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_DISABLE), // Interrupt In
+		usb.HID_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_DISABLE), // Interrupt Out
+		usb.MIDI_ENDPOINT_IN:  (usb.ENDPOINT_TYPE_DISABLE), // Bulk In
+		usb.MIDI_ENDPOINT_OUT: (usb.ENDPOINT_TYPE_DISABLE), // Bulk Out
+	}
 )
 
 // Configure the USB peripheral. The config is here for compatibility with the UART interface.
@@ -182,10 +197,9 @@ func handleUSBIRQ(intr interrupt.Interrupt) {
 		setEPINTFLAG(i, epFlags)
 		if (epFlags & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT0) > 0 {
 			buf := handleEndpointRx(i)
-			if usbRxHandler[i] != nil {
-				usbRxHandler[i](buf)
+			if usbRxHandler[i] == nil || usbRxHandler[i](buf) {
+				AckUsbOutTransfer(i)
 			}
-			handleEndpointRxComplete(i)
 		} else if (epFlags & sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1) > 0 {
 			if usbTxHandler[i] != nil {
 				usbTxHandler[i]()
@@ -405,7 +419,8 @@ func handleEndpointRx(ep uint32) []byte {
 	return udd_ep_out_cache_buffer[ep][:count]
 }
 
-func handleEndpointRxComplete(ep uint32) {
+// AckUsbOutTransfer is called to acknowledge the completion of a USB OUT transfer.
+func AckUsbOutTransfer(ep uint32) {
 	// set byte count to zero
 	usbEndpointDescriptors[ep].DeviceDescBank[0].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
 

src/machine/machine_nrf52840_usb.go

@@ -11,6 +11,8 @@ import (
 	"unsafe"
 )
 
+const NumberOfUSBEndpoints = 8
+
 var (
 	sendOnEP0DATADONE struct {
 		ptr    *byte
@@ -20,6 +22,17 @@ var (
 	epinen      uint32
 	epouten     uint32
 	easyDMABusy volatile.Register8
+
+	endPoints = []uint32{
+		usb.CONTROL_ENDPOINT:  usb.ENDPOINT_TYPE_CONTROL,
+		usb.CDC_ENDPOINT_ACM:  (usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointIn),
+		usb.CDC_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_BULK | usb.EndpointOut),
+		usb.CDC_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_BULK | usb.EndpointIn),
+		usb.HID_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_DISABLE), // Interrupt In
+		usb.HID_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_DISABLE), // Interrupt Out
+		usb.MIDI_ENDPOINT_IN:  (usb.ENDPOINT_TYPE_DISABLE), // Bulk In
+		usb.MIDI_ENDPOINT_OUT: (usb.ENDPOINT_TYPE_DISABLE), // Bulk Out
+	}
 )
 
 // enterCriticalSection is used to protect access to easyDMA - only one thing
@@ -193,10 +206,9 @@ func handleUSBIRQ(interrupt.Interrupt) {
 		if nrf.USBD.EVENTS_ENDEPOUT[i].Get() > 0 {
 			nrf.USBD.EVENTS_ENDEPOUT[i].Set(0)
 			buf := handleEndpointRx(uint32(i))
-			if usbRxHandler[i] != nil {
-				usbRxHandler[i](buf)
+			if usbRxHandler[i] == nil || usbRxHandler[i](buf) {
+				AckUsbOutTransfer(uint32(i))
 			}
-			handleEndpointRxComplete(uint32(i))
 			exitCriticalSection()
 		}
 	}
@@ -291,7 +303,8 @@ func handleEndpointRx(ep uint32) []byte {
 	return udd_ep_out_cache_buffer[ep][:count]
 }
 
-func handleEndpointRxComplete(ep uint32) {
+// AckUsbOutTransfer is called to acknowledge the completion of a USB OUT transfer.
+func AckUsbOutTransfer(ep uint32) {
 	// set ready for next data
 	nrf.USBD.SIZE.EPOUT[ep].Set(0)
 }

src/machine/machine_rp2040_usb.go

@@ -95,10 +95,9 @@ func handleUSBIRQ(intr interrupt.Interrupt) {
 		for i := 0; i < 16; i++ {
 			if s2&(1<<(i*2+1)) > 0 {
 				buf := handleEndpointRx(uint32(i))
-				if usbRxHandler[i] != nil {
-					usbRxHandler[i](buf)
+				if usbRxHandler[i] == nil || usbRxHandler[i](buf) {
+					AckUsbOutTransfer(uint32(i))
 				}
-				handleEndpointRxComplete(uint32(i))
 			}
 		}
 

src/machine/machine_rp2350_usb.go

@@ -98,10 +98,9 @@ func handleUSBIRQ(intr interrupt.Interrupt) {
 		for i := 0; i < 16; i++ {
 			if s2&(1<<(i*2+1)) > 0 {
 				buf := handleEndpointRx(uint32(i))
-				if usbRxHandler[i] != nil {
-					usbRxHandler[i](buf)
+				if usbRxHandler[i] == nil || usbRxHandler[i](buf) {
+					AckUsbOutTransfer(uint32(i))
 				}
-				handleEndpointRxComplete(uint32(i))
 			}
 		}
 

src/machine/machine_rp2_usb.go

@@ -8,12 +8,25 @@ import (
 	"unsafe"
 )
 
+const NumberOfUSBEndpoints = 10
+
 var (
 	sendOnEP0DATADONE struct {
 		offset int
 		data   []byte
 		pid    uint32
 	}
+
+	endPoints = []uint32{
+		usb.CONTROL_ENDPOINT:  usb.ENDPOINT_TYPE_CONTROL,
+		usb.CDC_ENDPOINT_ACM:  (usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointIn),
+		usb.CDC_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_BULK | usb.EndpointOut),
+		usb.CDC_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_BULK | usb.EndpointIn),
+		usb.HID_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_DISABLE), // Interrupt In
+		usb.HID_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_DISABLE), // Interrupt Out
+		usb.MIDI_ENDPOINT_IN:  (usb.ENDPOINT_TYPE_DISABLE), // Bulk In
+		usb.MIDI_ENDPOINT_OUT: (usb.ENDPOINT_TYPE_DISABLE), // Bulk Out
+	}
 )
 
 func initEndpoint(ep, config uint32) {
@@ -115,7 +128,9 @@ func handleEndpointRx(ep uint32) []byte {
 	return _usbDPSRAM.EPxBuffer[ep].Buffer0[:sz]
 }
 
-func handleEndpointRxComplete(ep uint32) {
+// AckUsbOutTransfer is called to acknowledge the completion of a USB OUT transfer.
+func AckUsbOutTransfer(ep uint32) {
+	ep = ep & 0x7F
 	setEPDataPID(ep, !epXdata0[ep])
 }
 
@@ -152,23 +167,25 @@ func sendViaEPIn(ep uint32, data []byte, count int) {
 
 // Set ENDPOINT_HALT/stall status on a USB IN endpoint.
 func (dev *USBDevice) SetStallEPIn(ep uint32) {
+	ep = ep & 0x7F
 	// Prepare buffer control register value
 	if ep == 0 {
 		armEPZeroStall()
 	}
 	val := uint32(usbBuf0CtrlFull)
-	_usbDPSRAM.EPxBufferControl[ep&0x7F].In.Set(val)
+	_usbDPSRAM.EPxBufferControl[ep].In.Set(val)
 	val |= uint32(usbBuf0CtrlStall)
-	_usbDPSRAM.EPxBufferControl[ep&0x7F].In.Set(val)
+	_usbDPSRAM.EPxBufferControl[ep].In.Set(val)
 }
 
 // Set ENDPOINT_HALT/stall status on a USB OUT endpoint.
 func (dev *USBDevice) SetStallEPOut(ep uint32) {
+	ep = ep & 0x7F
 	if ep == 0 {
 		panic("SetStallEPOut: EP0 OUT not valid")
 	}
 	val := uint32(usbBuf0CtrlStall)
-	_usbDPSRAM.EPxBufferControl[ep&0x7F].Out.Set(val)
+	_usbDPSRAM.EPxBufferControl[ep].Out.Set(val)
 }
 
 // Clear the ENDPOINT_HALT/stall on a USB IN endpoint.
@@ -178,7 +195,7 @@ func (dev *USBDevice) ClearStallEPIn(ep uint32) {
 	_usbDPSRAM.EPxBufferControl[ep].In.ClearBits(val)
 	if epXPIDReset[ep] {
 		// Reset the PID to DATA0
-		setEPDataPID(ep&0x7F, false)
+		setEPDataPID(ep, false)
 	}
 }
 

src/machine/usb.go

@@ -94,7 +94,7 @@ var (
 )
 
 var (
-	usbEndpointDescriptors [usb.NumberOfEndpoints]descriptor.Device
+	usbEndpointDescriptors [NumberOfUSBEndpoints]descriptor.Device
 
 	isEndpointHalt        = false
 	isRemoteWakeUpEnabled = false
@@ -107,10 +107,10 @@ var (
 var udd_ep_control_cache_buffer [256]uint8
 
 //go:align 4
-var udd_ep_in_cache_buffer [usb.NumberOfEndpoints][64]uint8
+var udd_ep_in_cache_buffer [NumberOfUSBEndpoints][64]uint8
 
 //go:align 4
-var udd_ep_out_cache_buffer [usb.NumberOfEndpoints][64]uint8
+var udd_ep_out_cache_buffer [NumberOfUSBEndpoints][64]uint8
 
 // usb_trans_buffer max size is 255 since that is max size
 // for a descriptor (bLength is 1 byte), and the biggest use
@@ -120,21 +120,10 @@ var udd_ep_out_cache_buffer [usb.NumberOfEndpoints][64]uint8
 var usb_trans_buffer [255]uint8
 
 var (
-	usbTxHandler    [usb.NumberOfEndpoints]func()
-	usbRxHandler    [usb.NumberOfEndpoints]func([]byte)
+	usbTxHandler    [NumberOfUSBEndpoints]func()
+	usbRxHandler    [NumberOfUSBEndpoints]func([]byte) bool
 	usbSetupHandler [usb.NumberOfInterfaces]func(usb.Setup) bool
-	usbStallHandler [usb.NumberOfEndpoints]func(usb.Setup) bool
-
-	endPoints = []uint32{
-		usb.CONTROL_ENDPOINT:  usb.ENDPOINT_TYPE_CONTROL,
-		usb.CDC_ENDPOINT_ACM:  (usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointIn),
-		usb.CDC_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_BULK | usb.EndpointOut),
-		usb.CDC_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_BULK | usb.EndpointIn),
-		usb.HID_ENDPOINT_IN:   (usb.ENDPOINT_TYPE_DISABLE), // Interrupt In
-		usb.HID_ENDPOINT_OUT:  (usb.ENDPOINT_TYPE_DISABLE), // Interrupt Out
-		usb.MIDI_ENDPOINT_IN:  (usb.ENDPOINT_TYPE_DISABLE), // Bulk In
-		usb.MIDI_ENDPOINT_OUT: (usb.ENDPOINT_TYPE_DISABLE), // Bulk Out
-	}
+	usbStallHandler [NumberOfUSBEndpoints]func(usb.Setup) bool
 )
 
 // sendDescriptor creates and sends the various USB descriptor types that
@@ -213,7 +202,7 @@ func handleStandardSetup(setup usb.Setup) bool {
 		if setup.WValueL == 1 { // DEVICEREMOTEWAKEUP
 			isRemoteWakeUpEnabled = false
 		} else if setup.WValueL == 0 { // ENDPOINTHALT
-			if idx := setup.WIndex & 0x7F; idx < usb.NumberOfEndpoints && usbStallHandler[idx] != nil {
+			if idx := setup.WIndex & 0x7F; idx < NumberOfUSBEndpoints && usbStallHandler[idx] != nil {
 				// Host has requested to clear an endpoint stall. If the request is addressed to
 				// an endpoint with a configured StallHandler, forward the message on.
 				// The 0x7F mask is used to clear the direction bit from the endpoint number
@@ -228,7 +217,7 @@ func handleStandardSetup(setup usb.Setup) bool {
 		if setup.WValueL == 1 { // DEVICEREMOTEWAKEUP
 			isRemoteWakeUpEnabled = true
 		} else if setup.WValueL == 0 { // ENDPOINTHALT
-			if idx := setup.WIndex & 0x7F; idx < usb.NumberOfEndpoints && usbStallHandler[idx] != nil {
+			if idx := setup.WIndex & 0x7F; idx < NumberOfUSBEndpoints && usbStallHandler[idx] != nil {
 				// Host has requested to stall an endpoint. If the request is addressed to
 				// an endpoint with a configured StallHandler, forward the message on.
 				// The 0x7F mask is used to clear the direction bit from the endpoint number
@@ -330,7 +319,12 @@ func ConfigureUSBEndpoint(desc descriptor.Descriptor, epSettings []usb.EndpointC
 		} else {
 			endPoints[ep.Index] = uint32(ep.Type | usb.EndpointOut)
 			if ep.RxHandler != nil {
-				usbRxHandler[ep.Index] = ep.RxHandler
+				usbRxHandler[ep.Index] = func(b []byte) bool {
+					ep.RxHandler(b)
+					return true
+				}
+			} else if ep.DelayRxHandler != nil {
+				usbRxHandler[ep.Index] = ep.DelayRxHandler
 			}
 		}
 		if ep.StallHandler != nil {

src/machine/usb/config.go

@@ -1,12 +1,13 @@
 package usb
 
 type EndpointConfig struct {
-	Index        uint8
-	IsIn         bool
-	TxHandler    func()
-	RxHandler    func([]byte)
-	StallHandler func(Setup) bool
-	Type         uint8
+	Index          uint8
+	IsIn           bool
+	TxHandler      func()
+	RxHandler      func([]byte)
+	DelayRxHandler func([]byte) bool
+	StallHandler   func(Setup) bool
+	Type           uint8
 }
 
 type SetupConfig struct {