Implement RFC 55: New lib.io components.

Author: wanda-phi

amaranth/build/res.py

@@ -1,8 +1,10 @@
+import warnings
 from collections import OrderedDict
 
 from ..hdl import *
 from ..hdl._ast import SignalDict
 from ..lib import wiring, io
+from .._utils import _ignore_deprecated
 
 from .dsl import *
 
@@ -247,7 +249,11 @@ def resolve(resource, dir, xdr, path, attrs):
                 if dir == "-":
                     return port
                 else:
-                    pin = wiring.flipped(io.Pin(len(phys), dir, xdr=xdr, path=path))
+                    warnings.warn(f"Using platform.request without `dir=\"-\"` is deprecated; "
+                                  f"use `amaranth.lib.io.*Buffer` components instead",
+                                  DeprecationWarning, stacklevel=2)
+                    with _ignore_deprecated():
+                        pin = wiring.flipped(io.Pin(len(phys), dir, xdr=xdr, path=path))
                     buffer = PinBuffer(pin, port)
                     self._pins.append((pin, port, buffer))
 

amaranth/lib/io.py

@@ -6,6 +6,7 @@
 from ..hdl import *
 from ..lib import wiring, data
 from ..lib.wiring import In, Out
+from .._utils import deprecated, _ignore_deprecated
 from .. import tracer
 
 
@@ -708,6 +709,8 @@ class Signature(wiring.Signature):
         """A signature for :class:`Pin`.  The parameters are as defined on the ``Pin`` class,
         and are accessible as attributes.
         """
+        # TODO(amaranth-0.6): remove
+        @deprecated("`amaranth.lib.io.Pin` is deprecated, use `amaranth.lib.io.*Buffer` instead")
         def __init__(self, width, dir, *, xdr=0):
             if not isinstance(width, int) or width < 0:
                 raise TypeError("Width must be a non-negative integer, not {!r}"
@@ -761,17 +764,20 @@ def __repr__(self):
         def create(self, *, path=None, src_loc_at=0):
             return Pin(self.width, self.dir, xdr=self.xdr, path=path, src_loc_at=1 + src_loc_at)
 
+    # TODO(amaranth-0.6): remove
+    @deprecated("`amaranth.lib.io.Pin` is deprecated, use `amaranth.lib.io.*Buffer` instead")
     def __init__(self, width, dir, *, xdr=0, name=None, path=None, src_loc_at=0):
         if name is not None:
             if path is not None:
                 raise ValueError("Cannot pass both name and path")
             path = (name,)
         if path is None:
-            name = tracer.get_var_name(depth=2 + src_loc_at, default="$pin")
+            name = tracer.get_var_name(depth=3 + src_loc_at, default="$pin")
             path = (name,)
         self.path = tuple(path)
         self.name = "__".join(path)
-        signature = Pin.Signature(width, dir, xdr=xdr)
+        with _ignore_deprecated():
+            signature = Pin.Signature(width, dir, xdr=xdr)
         super().__init__(signature, path=path, src_loc_at=src_loc_at + 1)
 
     @property

docs/changes.rst

@@ -41,7 +41,8 @@ Apply the following changes to code written against Amaranth 0.4 to migrate it t
 * Remove any usage of ``name=`` with assertions, possibly replacing them with custom messages
 * Ensure all elaboratables are subclasses of :class:`Elaboratable`
 * Ensure clock domains aren't used outside the module that defines them, or its submodules; move clock domain definitions upwards in the hierarchy as necessary
-* Remove uses of ``amaranth.lib.coding.*`` by inlining or copying the implementation of the modules.
+* Remove uses of ``amaranth.lib.coding.*`` by inlining or copying the implementation of the modules
+* Update uses of ``platform.request`` to pass ``dir="-"`` and use :mod:`amaranth.lib.io` buffers
 
 
 Implemented RFCs
@@ -71,6 +72,7 @@ Implemented RFCs
 * `RFC 50`_: ``Print`` statement and string formatting
 * `RFC 51`_: Add ``ShapeCastable.from_bits`` and ``amaranth.lib.data.Const``
 * `RFC 53`_: Low-level I/O primitives
+* `RFC 55`_: New ``lib.io`` components
 * `RFC 58`_: Core support for ``ValueCastable`` formatting
 * `RFC 59`_: Get rid of upwards propagation of clock domains
 * `RFC 62`_: The ``MemoryData`` class

tests/test_build_res.py

@@ -5,6 +5,7 @@
 from amaranth.lib.io import *
 from amaranth.build.dsl import *
 from amaranth.build.res import *
+from amaranth._utils import _ignore_deprecated
 
 from .utils import *
 
@@ -56,7 +57,8 @@ def test_lookup(self):
 
     def test_request_basic(self):
         r = self.cm.lookup("user_led", 0)
-        user_led = self.cm.request("user_led", 0)
+        with _ignore_deprecated():
+            user_led = self.cm.request("user_led", 0)
 
         self.assertIsInstance(flipped(user_led), Pin)
         self.assertEqual(user_led.o.name, "user_led_0__o")
@@ -74,12 +76,14 @@ def test_request_basic(self):
         self.assertEqual(port.invert, (False,))
 
     def test_request_with_dir(self):
-        i2c = self.cm.request("i2c", 0, dir={"sda": "o"})
+        with _ignore_deprecated():
+            i2c = self.cm.request("i2c", 0, dir={"sda": "o"})
         self.assertIsInstance(flipped(i2c.sda), Pin)
         self.assertEqual(i2c.sda.dir, "o")
 
     def test_request_tristate(self):
-        i2c = self.cm.request("i2c", 0)
+        with _ignore_deprecated():
+            i2c = self.cm.request("i2c", 0)
         self.assertEqual(i2c.sda.dir, "io")
 
         ((scl_pin, scl_port, _), (sda_pin, sda_port, _)) = self.cm.iter_pins()
@@ -91,7 +95,8 @@ def test_request_tristate(self):
         self.assertEqual(sda_port.io.metadata[0].name, "N11")
 
     def test_request_diffpairs(self):
-        clk100 = self.cm.request("clk100", 0)
+        with _ignore_deprecated():
+            clk100 = self.cm.request("clk100", 0)
         self.assertIsInstance(flipped(clk100), Pin)
         self.assertEqual(clk100.dir, "i")
         self.assertEqual(clk100.width, 1)
@@ -112,8 +117,10 @@ def test_request_inverted(self):
         ]
         self.cm.add_resources(new_resources)
 
-        cs = self.cm.request("cs")
-        clk = self.cm.request("clk")
+        with _ignore_deprecated():
+            cs = self.cm.request("cs")
+            clk = self.cm.request("clk")
+
         (
             (cs_pin, cs_port, _),
             (clk_pin, clk_port, _),
@@ -144,7 +151,8 @@ def test_request_via_connector(self):
                 Subsignal("mosi", Pins("4", conn=("pmod", 0))),
             )
         ])
-        spi0 = self.cm.request("spi", 0)
+        with _ignore_deprecated():
+            spi0 = self.cm.request("spi", 0)
         (
             (ss_pin, ss_port, _),
             (clk_pin, clk_port, _),
@@ -173,7 +181,8 @@ def test_request_via_nested_connector(self):
                 Subsignal("mosi", Pins("4", conn=("pmod_extension", 0))),
             )
         ])
-        spi0 = self.cm.request("spi", 0)
+        with _ignore_deprecated():
+            spi0 = self.cm.request("spi", 0)
         (
             (ss_pin, ss_port, _),
             (clk_pin, clk_port, _),
@@ -190,8 +199,9 @@ def test_request_via_nested_connector(self):
         self.assertEqual(mosi_port.io.metadata[0].name, "B3")
 
     def test_request_clock(self):
-        clk100 = self.cm.request("clk100", 0)
-        clk50 = self.cm.request("clk50", 0, dir="i")
+        with _ignore_deprecated():
+            clk100 = self.cm.request("clk100", 0)
+            clk50 = self.cm.request("clk50", 0, dir="i")
         (
             (clk100_pin, clk100_port, _),
             (clk50_pin, clk50_port, _),
@@ -202,7 +212,8 @@ def test_request_clock(self):
         ])
 
     def test_add_clock(self):
-        i2c = self.cm.request("i2c")
+        with _ignore_deprecated():
+            i2c = self.cm.request("i2c")
         self.cm.add_clock_constraint(i2c.scl.o, 100e3)
         self.assertEqual(list(self.cm.iter_clock_constraints()), [
             (i2c.scl.o, None, 100e3)
@@ -246,18 +257,21 @@ def test_wrong_clock_frequency(self):
     def test_wrong_request_duplicate(self):
         with self.assertRaisesRegex(ResourceError,
                 r"^Resource user_led#0 has already been requested$"):
-            self.cm.request("user_led", 0)
-            self.cm.request("user_led", 0)
+            with _ignore_deprecated():
+                self.cm.request("user_led", 0)
+                self.cm.request("user_led", 0)
 
     def test_wrong_request_duplicate_physical(self):
         self.cm.add_resources([
             Resource("clk20", 0, Pins("H1", dir="i")),
         ])
-        self.cm.request("clk100", 0)
+        with _ignore_deprecated():
+            self.cm.request("clk100", 0)
         with self.assertRaisesRegex(ResourceError,
                 (r"^Resource component clk20_0 uses physical pin H1, but it is already "
                     r"used by resource component clk100_0 that was requested earlier$")):
-            self.cm.request("clk20", 0)
+            with _ignore_deprecated():
+                self.cm.request("clk20", 0)
 
     def test_wrong_request_with_dir(self):
         with self.assertRaisesRegex(TypeError,
@@ -292,7 +306,8 @@ def test_wrong_request_with_xdr_dict(self):
             i2c = self.cm.request("i2c", 0, xdr=2)
 
     def test_wrong_clock_constraint_twice(self):
-        clk100 = self.cm.request("clk100")
+        with _ignore_deprecated():
+            clk100 = self.cm.request("clk100")
         with self.assertRaisesRegex(ValueError,
                 (r"^Cannot add clock constraint on \(sig clk100_0__i\), which is already "
                     r"constrained to 100000000\.0 Hz$")):