csr.reg: migrate to lib.wiring components.

Also, fix FieldPort signature direction.

amaranth_soc/csr/reg.py

@@ -1,7 +1,7 @@
 from collections.abc import Mapping, Sequence
 from amaranth import *
 from amaranth.lib import enum, wiring
-from amaranth.lib.wiring import In, Out
+from amaranth.lib.wiring import In, Out, connect, flipped
 
 from ..memory import MemoryMap
 from .bus import Element, Multiplexer
@@ -57,10 +57,10 @@ def __init__(self, shape, access):
             self._access = FieldPort.Access(access)
 
             members = {
-                "r_data": Out(self.shape),
-                "r_stb":  In(1),
-                "w_data": In(self.shape),
-                "w_stb":  In(1),
+                "r_data": In(self.shape),
+                "r_stb":  Out(1),
+                "w_data": Out(self.shape),
+                "w_stb":  Out(1),
             }
             super().__init__(members)
 
@@ -154,7 +154,7 @@ def __repr__(self):
         return f"csr.FieldPort({self.signature!r})"
 
 
-class Field(Elaboratable):
+class Field(wiring.Component):
     _doc_template = """
     {description}
 
@@ -181,15 +181,24 @@ class Field(Elaboratable):
     attributes="")
 
     def __init__(self, shape, access):
-        self.port = FieldPort.Signature(shape, access).create(path=("port",))
+        FieldPort.Signature.check_parameters(shape, access)
+        self._shape  = Shape.cast(shape)
+        self._access = FieldPort.Access(access)
+        super().__init__()
 
     @property
     def shape(self):
-        return self.port.shape
+        return self._shape
 
     @property
     def access(self):
-        return self.port.access
+        return self._access
+
+    @property
+    def signature(self):
+        return wiring.Signature({
+            "port": Out(FieldPort.Signature(self._shape, self._access)),
+        })
 
 
 class FieldMap(Mapping):
@@ -346,7 +355,7 @@ def flatten(self):
                 assert False # :nocov:
 
 
-class Register(Elaboratable):
+class Register(wiring.Component):
     """CSR register.
 
     Parameters
@@ -407,8 +416,10 @@ def __init__(self, access="rw", fields=None):
                 raise ValueError(f"Field {'__'.join(field_name)} is writable, but register access "
                                  f"mode is {access!r}")
 
-        self.element = Element.Signature(width, access).create(path=("element",))
+        self._width  = width
+        self._access = access
         self._fields = fields
+        super().__init__()
 
     @property
     def fields(self):
@@ -418,6 +429,12 @@ def fields(self):
     def f(self):
         return self._fields
 
+    @property
+    def signature(self):
+        return wiring.Signature({
+            "element": Out(Element.Signature(self._width, self._access)),
+        })
+
     def __iter__(self):
         """Recursively iterate over the field collection.
 
@@ -684,7 +701,7 @@ def get_register(self, path):
         raise KeyError(path)
 
 
-class Bridge(Elaboratable):
+class Bridge(wiring.Component):
     """CSR bridge.
 
     Parameters
@@ -754,18 +771,20 @@ def get_register_param(path, root, kind):
 
         self._map = register_map
         self._mux = Multiplexer(memory_map)
+        super().__init__()
 
     @property
     def register_map(self):
         return self._map
 
     @property
-    def bus(self):
-        return self._mux.bus
+    def signature(self):
+        return self._mux.signature
 
     def elaborate(self, platform):
         m = Module()
         for register, path in self.register_map.flatten():
             m.submodules["__".join(path)] = register
         m.submodules.mux = self._mux
+        connect(m, flipped(self), self._mux)
         return m

tests/test_csr_reg.py

@@ -15,43 +15,43 @@ def test_shape_1_ro(self):
         self.assertEqual(sig.shape, unsigned(1))
         self.assertEqual(sig.access, FieldPort.Access.R)
         self.assertEqual(sig.members, Signature({
-            "r_data": Out(unsigned(1)),
-            "r_stb":  In(1),
-            "w_data": In(unsigned(1)),
-            "w_stb":  In(1),
+            "r_data": In(unsigned(1)),
+            "r_stb":  Out(1),
+            "w_data": Out(unsigned(1)),
+            "w_stb":  Out(1),
         }).members)
 
     def test_shape_8_rw(self):
         sig = FieldPort.Signature(8, "rw")
         self.assertEqual(sig.shape, unsigned(8))
         self.assertEqual(sig.access, FieldPort.Access.RW)
         self.assertEqual(sig.members, Signature({
-            "r_data": Out(unsigned(8)),
-            "r_stb":  In(1),
-            "w_data": In(unsigned(8)),
-            "w_stb":  In(1),
+            "r_data": In(unsigned(8)),
+            "r_stb":  Out(1),
+            "w_data": Out(unsigned(8)),
+            "w_stb":  Out(1),
         }).members)
 
     def test_shape_10_wo(self):
         sig = FieldPort.Signature(10, "w")
         self.assertEqual(sig.shape, unsigned(10))
         self.assertEqual(sig.access, FieldPort.Access.W)
         self.assertEqual(sig.members, Signature({
-            "r_data": Out(unsigned(10)),
-            "r_stb":  In(1),
-            "w_data": In(unsigned(10)),
-            "w_stb":  In(1),
+            "r_data": In(unsigned(10)),
+            "r_stb":  Out(1),
+            "w_data": Out(unsigned(10)),
+            "w_stb":  Out(1),
         }).members)
 
     def test_shape_0_rw(self):
         sig = FieldPort.Signature(0, "w")
         self.assertEqual(sig.shape, unsigned(0))
         self.assertEqual(sig.access, FieldPort.Access.W)
         self.assertEqual(sig.members, Signature({
-            "r_data": Out(unsigned(0)),
-            "r_stb":  In(1),
-            "w_data": In(unsigned(0)),
-            "w_stb":  In(1),
+            "r_data": In(unsigned(0)),
+            "r_stb":  Out(1),
+            "w_data": Out(unsigned(0)),
+            "w_stb":  Out(1),
         }).members)
 
     def test_create(self):