implement USBTokenGenerator

luna/gateware/usb/usb2/host/packet.py

@@ -0,0 +1,125 @@
+#
+# This file is part of usb2-highspeed-core
+#
+# Copyright (c) 2021 Hans Baier <hansfbaier@gmail.com>
+# SPDX-License-Identifier: BSD-3-Clause
+
+""" Contains the gatware module necessary to interpret and generate low-level USB host packets. """
+
+
+import operator
+import unittest
+import functools
+
+from nmigen            import Signal, Module, Elaboratable, Cat, Array, Const
+from nmigen.build      import Platform
+from nmigen.hdl.rec    import Record, DIR_FANIN, DIR_FANOUT
+
+
+from ..                 import USBSpeed, USBPacketID
+from ...stream          import USBInStreamInterface, USBOutStreamInterface
+from ....interface.utmi import UTMITransmitInterface
+from ....test           import LunaGatewareTestCase, usb_domain_test_case
+
+from ..packet           import USBTokenDetector
+
+
+
+class TokenGeneratorInterface(Record):
+    """ Record providing an interface to a USB token generator.
+
+    Attributes
+    ----------
+    pid: Signal(4), input
+        The Packet ID of the token.
+    payload: Signal(11), input
+        The payload of the token.
+
+    new_token: Signal(), input
+        Strobe asserted for a single cycle when a new token packet should be sent.
+    """
+
+    def __init__(self):
+        super().__init__([
+            ('pid',                4, DIR_FANIN),
+            ('payload',           11, DIR_FANIN),
+            ('new_token',          1, DIR_FANIN),
+        ])
+
+class USBTokenGenerator(Elaboratable):
+    """ Gateware that generates token packets, including SOF
+
+    Attributes
+    ----------
+    interface: TokenGeneratorInterface
+        The interface that specifies the Token to be constructed
+    speed: Signal(2), input
+        Carries a ``USBSpeed`` constant identifying the device's current operating speed.
+
+    Parameters
+    ----------
+        utmi: UTMIInterface
+            The UTMI bus to transmit on.
+    """
+
+    def __init__(self, *, utmi, domain_clock=60e6):
+        self.utmi = utmi
+        self._domain_clock = domain_clock
+
+        #
+        # I/O port
+        #
+        self.interface = TokenGeneratorInterface()
+        self.speed     = Signal(2)
+
+    def elaborate(self, platform: Platform) -> Module:
+        m = Module()
+        interface = self.interface
+        utmi      = self.utmi
+
+        token_data    = Signal(24)
+        token_crc     = Signal(5)
+
+        m.d.comb += token_crc.eq(USBTokenDetector.generate_crc_for_token(interface.payload))
+
+        m.d.usb += [
+            token_data.eq(
+                Cat(
+                    interface.pid,
+                    ~interface.pid,
+                    interface.payload,
+                    token_crc))
+        ]
+
+        with m.FSM(domain="usb"):
+
+            # waiting for a new packet to be sent
+            with m.State("IDLE"):
+                with m.If(utmi.tx_ready & interface.new_token):
+                    m.next = "PID"
+
+            with m.State("PID"):
+                with m.If(utmi.tx_ready):
+                    m.d.comb += [
+                        utmi.tx_data.eq(token_data[0:8]),
+                        utmi.tx_valid.eq(1),
+                    ]
+                    m.next = "PAYLOAD0"
+
+            with m.State("PAYLOAD0"):
+                with m.If(utmi.tx_ready):
+                    m.d.comb += [
+                        utmi.tx_data.eq(token_data[8:16]),
+                        utmi.tx_valid.eq(1),
+                    ]
+                    m.next = "PAYLOAD1"
+
+            with m.State("PAYLOAD1"):
+                with m.If(utmi.tx_ready):
+                    m.d.comb += [
+                        utmi.tx_data.eq(token_data[16:24]),
+                        utmi.tx_valid.eq(1),
+                    ]
+                    m.next = "IDLE"
+
+        return m

requirements.txt

@@ -6,7 +6,7 @@ pyusb
 -e git://github.com/hansfbaier/nmigen-library.git#egg=nmigen_library
 -e git://github.com/lambdaconcept/minerva.git#egg=minerva
 -e git://github.com/lambdaconcept/lambdasoc.git#egg=lambdasoc
--e git://github.com/usb-tools/python-usb-protocol.git#egg=usb_protocol
+-e git://github.com/hansfbaier/python-usb-descriptors.git#egg=usb_descriptors
 -e git://github.com/greatscottgadgets/apollo.git#egg=apollo
 pyvcd
 pyserial~=3.4