usb: Add a dummy handler for the ACM SET_LINE_CODING request.

Author: zyp

orbtrace/cdc_acm.py

@@ -0,0 +1,77 @@
+from amaranth import *
+from usb_protocol.types import USBRequestType, USBRequestRecipient
+
+from luna.gateware.usb.usb2.request import USBRequestHandler
+from luna.gateware.usb.stream import USBInStreamInterface
+from luna.gateware.stream.generator import StreamSerializer
+
+class ACMRequestHandler(USBRequestHandler):
+    def __init__(self, if_num):
+        super().__init__()
+
+        self.if_num = if_num
+
+        self.new_request = Signal()
+        self.request_done = Signal()
+
+    def handle_set_line_coding(self, m):
+        with m.If(self.interface.rx_ready_for_response):
+            m.d.comb += self.interface.handshakes_out.ack.eq(1)
+
+        with m.If(self.interface.status_requested):
+            m.d.comb += self.send_zlp()
+            m.d.comb += self.request_done.eq(1)
+
+    def handle_unhandled(self, m):
+        interface = self.interface
+
+        with m.If(interface.rx_ready_for_response | interface.data_requested | interface.status_requested):
+            m.d.comb += [
+                interface.handshakes_out.stall.eq(1),
+                self.request_done.eq(1),
+            ]
+
+    def transition(self, m):
+        setup = self.interface.setup
+
+        with m.If(self.request_done):
+            m.next = 'IDLE'
+
+        targeting_if = (setup.recipient == USBRequestRecipient.INTERFACE) & (setup.index == self.if_num)
+
+        with m.If(setup.received & targeting_if):
+            m.next = 'DISPATCH'
+
+    def elaborate(self, platform):
+        m = Module()
+
+        m.submodules.transmitter = self.transmitter = StreamSerializer(data_length = 6, domain = 'usb', stream_type=USBInStreamInterface)
+
+        interface         = self.interface
+        setup             = self.interface.setup
+
+        m.d.usb += self.new_request.eq(0)
+
+        with m.FSM(domain = 'usb'):
+            with m.State('IDLE'):
+                self.transition(m)
+
+            with m.State('DISPATCH'):
+                m.d.usb += self.new_request.eq(1)
+
+                m.next = 'UNHANDLED'
+
+                with m.If(setup.type == USBRequestType.CLASS):
+                    with m.Switch(setup.request):
+                        with m.Case(0x20): # SET_LINE_CODING
+                            m.next = 'SET_LINE_CODING'
+            
+            with m.State('SET_LINE_CODING'):
+                self.handle_set_line_coding(m)
+                self.transition(m)
+
+            with m.State('UNHANDLED'):
+                self.handle_unhandled(m)
+                self.transition(m)
+
+        return m

orbtrace/soc.py

@@ -20,6 +20,8 @@
 
 from .usb_serialnumber import USBSerialNumberHandler
 
+from .cdc_acm import ACMRequestHandler
+
 from .flash_uid import FlashUID
 from .flashwriter import FlashWriter
 
@@ -601,6 +603,10 @@ def add_usb_uart(self, uart):
 
         self.submodules += in_cdc, out_cdc, pipeline
 
+        # Control request handler.
+        handler = ACMRequestHandler(comm_if)
+        self.add_usb_control_handler(handler)
+
     def add_usb_bridge(self):
         mem_request_handler = MemRequestHandler()