machine/rp2: expose usb endpoint stall handling

src/machine/machine_rp2040_usb.go

@@ -67,7 +67,7 @@ func handleUSBIRQ(intr interrupt.Interrupt) {
 
 		if !ok {
 			// Stall endpoint?
-			sendStallViaEPIn(0)
+			USBDev.SetStallEPIn(0)
 		}
 
 	}

src/machine/machine_rp2350_usb.go

@@ -70,7 +70,7 @@ func handleUSBIRQ(intr interrupt.Interrupt) {
 
 		if !ok {
 			// Stall endpoint?
-			sendStallViaEPIn(0)
+			USBDev.SetStallEPIn(0)
 		}
 
 	}

src/machine/machine_rp2_usb.go

@@ -21,26 +21,33 @@ func initEndpoint(ep, config uint32) {
 	offset := ep*2*usbBufferLen + 0x100
 	val |= offset
 
+	// Bulk and interrupt endpoints must have their Packet ID reset to DATA0 when un-stalled.
+	epXPIDReset[ep] = false // Default to false in case an endpoint is re-initialized.
+
 	switch config {
 	case usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointIn:
 		val |= usbEpControlEndpointTypeInterrupt
 		_usbDPSRAM.EPxControl[ep].In.Set(val)
+		epXPIDReset[ep] = true
 
 	case usb.ENDPOINT_TYPE_BULK | usb.EndpointOut:
 		val |= usbEpControlEndpointTypeBulk
 		_usbDPSRAM.EPxControl[ep].Out.Set(val)
 		_usbDPSRAM.EPxBufferControl[ep].Out.Set(usbBufferLen & usbBuf0CtrlLenMask)
 		_usbDPSRAM.EPxBufferControl[ep].Out.SetBits(usbBuf0CtrlAvail)
+		epXPIDReset[ep] = true
 
 	case usb.ENDPOINT_TYPE_INTERRUPT | usb.EndpointOut:
 		val |= usbEpControlEndpointTypeInterrupt
 		_usbDPSRAM.EPxControl[ep].Out.Set(val)
 		_usbDPSRAM.EPxBufferControl[ep].Out.Set(usbBufferLen & usbBuf0CtrlLenMask)
 		_usbDPSRAM.EPxBufferControl[ep].Out.SetBits(usbBuf0CtrlAvail)
+		epXPIDReset[ep] = true
 
 	case usb.ENDPOINT_TYPE_BULK | usb.EndpointIn:
 		val |= usbEpControlEndpointTypeBulk
 		_usbDPSRAM.EPxControl[ep].In.Set(val)
+		epXPIDReset[ep] = true
 
 	case usb.ENDPOINT_TYPE_CONTROL:
 		val |= usbEpControlEndpointTypeControl
@@ -109,7 +116,12 @@ func handleEndpointRx(ep uint32) []byte {
 }
 
 func handleEndpointRxComplete(ep uint32) {
-	epXdata0[ep] = !epXdata0[ep]
+	setEPDataPID(ep, !epXdata0[ep])
+}
+
+// Set the USB endpoint Packet ID to DATA0 or DATA1.
+func setEPDataPID(ep uint32, dataOne bool) {
+	epXdata0[ep] = dataOne
 	if epXdata0[ep] || ep == 0 {
 		_usbDPSRAM.EPxBufferControl[ep].Out.SetBits(usbBuf0CtrlData1Pid)
 	}
@@ -138,7 +150,8 @@ func sendViaEPIn(ep uint32, data []byte, count int) {
 	_usbDPSRAM.EPxBufferControl[ep&0x7F].In.Set(val)
 }
 
-func sendStallViaEPIn(ep uint32) {
+// Set ENDPOINT_HALT/stall status on a USB IN endpoint.
+func (dev *USBDevice) SetStallEPIn(ep uint32) {
 	// Prepare buffer control register value
 	if ep == 0 {
 		armEPZeroStall()
@@ -149,6 +162,37 @@ func sendStallViaEPIn(ep uint32) {
 	_usbDPSRAM.EPxBufferControl[ep&0x7F].In.Set(val)
 }
 
+// Set ENDPOINT_HALT/stall status on a USB OUT endpoint.
+func (dev *USBDevice) SetStallEPOut(ep uint32) {
+	if ep == 0 {
+		panic("SetStallEPOut: EP0 OUT not valid")
+	}
+	val := uint32(usbBuf0CtrlStall)
+	_usbDPSRAM.EPxBufferControl[ep&0x7F].Out.Set(val)
+}
+
+// Clear the ENDPOINT_HALT/stall on a USB IN endpoint.
+func (dev *USBDevice) ClearStallEPIn(ep uint32) {
+	ep = ep & 0x7F
+	val := uint32(usbBuf0CtrlStall)
+	_usbDPSRAM.EPxBufferControl[ep].In.ClearBits(val)
+	if epXPIDReset[ep] {
+		// Reset the PID to DATA0
+		setEPDataPID(ep&0x7F, false)
+	}
+}
+
+// Clear the ENDPOINT_HALT/stall on a USB OUT endpoint.
+func (dev *USBDevice) ClearStallEPOut(ep uint32) {
+	ep = ep & 0x7F
+	val := uint32(usbBuf0CtrlStall)
+	_usbDPSRAM.EPxBufferControl[ep].Out.ClearBits(val)
+	if epXPIDReset[ep] {
+		// Reset the PID to DATA0
+		setEPDataPID(ep, false)
+	}
+}
+
 type usbDPSRAM struct {
 	// Note that EPxControl[0] is not EP0Control but 8-byte setup data.
 	EPxControl [16]usbEndpointControlRegister
@@ -173,9 +217,10 @@ type usbBuffer struct {
 }
 
 var (
-	_usbDPSRAM = (*usbDPSRAM)(unsafe.Pointer(uintptr(0x50100000)))
-	epXdata0   [16]bool
-	setupBytes [8]byte
+	_usbDPSRAM  = (*usbDPSRAM)(unsafe.Pointer(uintptr(0x50100000)))
+	epXdata0    [16]bool
+	epXPIDReset [16]bool
+	setupBytes  [8]byte
 )
 
 func (d *usbDPSRAM) setupBytes() []byte {

src/machine/usb.go

@@ -123,6 +123,7 @@ var (
 	usbTxHandler    [usb.NumberOfEndpoints]func()
 	usbRxHandler    [usb.NumberOfEndpoints]func([]byte)
 	usbSetupHandler [usb.NumberOfInterfaces]func(usb.Setup) bool
+	usbStallHandler [usb.NumberOfEndpoints]func(usb.Setup) bool
 
 	endPoints = []uint32{
 		usb.CONTROL_ENDPOINT:  usb.ENDPOINT_TYPE_CONTROL,
@@ -212,6 +213,12 @@ 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 {
+				// 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
+				return usbStallHandler[idx](setup)
+			}
 			isEndpointHalt = false
 		}
 		SendZlp()
@@ -221,6 +228,12 @@ 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 {
+				// 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
+				return usbStallHandler[idx](setup)
+			}
 			isEndpointHalt = true
 		}
 		SendZlp()
@@ -320,6 +333,9 @@ func ConfigureUSBEndpoint(desc descriptor.Descriptor, epSettings []usb.EndpointC
 				usbRxHandler[ep.Index] = ep.RxHandler
 			}
 		}
+		if ep.StallHandler != nil {
+			usbStallHandler[ep.Index] = ep.StallHandler
+		}
 	}
 
 	for _, s := range setup {

src/machine/usb/config.go

@@ -1,11 +1,12 @@
 package usb
 
 type EndpointConfig struct {
-	Index     uint8
-	IsIn      bool
-	TxHandler func()
-	RxHandler func([]byte)
-	Type      uint8
+	Index        uint8
+	IsIn         bool
+	TxHandler    func()
+	RxHandler    func([]byte)
+	StallHandler func(Setup) bool
+	Type         uint8
 }
 
 type SetupConfig struct {