[rp2040] Add variant config option for RP2040/RP2350 (#16602)

tests/components/rp2040/test.rp2040-ard.yaml

@@ -1,4 +1,5 @@
 rp2040:
+  variant: rp2040
   enable_full_printf: false
 
 logger:

tests/components/rp2040/test.rp2040-pico2-ard.yaml

@@ -0,0 +1,6 @@
+rp2040:
+  variant: rp2350
+  enable_full_printf: false
+
+logger:
+  level: VERBOSE

tests/unit_tests/components/test_rp2040.py

@@ -1,6 +1,11 @@
-"""Tests for RP2040 component public helpers."""
+"""Tests for RP2040 component public helpers and variant detection."""
 
-from esphome.components.rp2040 import board_id_has_wifi
+import pytest
+
+from esphome.components.rp2040 import _detect_variant, board_id_has_wifi
+from esphome.components.rp2040.const import VARIANT_RP2040, VARIANT_RP2350
+import esphome.config_validation as cv
+from esphome.const import CONF_BOARD, CONF_VARIANT
 
 
 def test_board_id_has_wifi_for_known_wifi_board() -> None:
@@ -27,3 +32,61 @@ def test_board_id_has_wifi_for_unknown_board_returns_true() -> None:
     "no CYW43" guard at compile time.
     """
     assert board_id_has_wifi("not-a-real-board-id") is True
+
+
+def test_detect_variant_derives_variant_from_board() -> None:
+    """Board alone resolves to the matching variant."""
+    result = _detect_variant({CONF_BOARD: "rpipicow"})
+    assert result[CONF_BOARD] == "rpipicow"
+    assert result[CONF_VARIANT] == VARIANT_RP2040
+
+
+def test_detect_variant_derives_variant_from_rp2350_board() -> None:
+    """An RP2350 board resolves to ``RP2350``."""
+    result = _detect_variant({CONF_BOARD: "rpipico2"})
+    assert result[CONF_BOARD] == "rpipico2"
+    assert result[CONF_VARIANT] == VARIANT_RP2350
+
+
+def test_detect_variant_only_picks_default_board_rp2040() -> None:
+    """Variant alone picks Pico W as the canonical RP2040 board."""
+    result = _detect_variant({CONF_VARIANT: VARIANT_RP2040})
+    assert result[CONF_BOARD] == "rpipicow"
+    assert result[CONF_VARIANT] == VARIANT_RP2040
+
+
+def test_detect_variant_only_picks_default_board_rp2350() -> None:
+    """Variant alone picks Pico 2 W as the canonical RP2350 board."""
+    result = _detect_variant({CONF_VARIANT: VARIANT_RP2350})
+    assert result[CONF_BOARD] == "rpipico2w"
+    assert result[CONF_VARIANT] == VARIANT_RP2350
+
+
+def test_detect_variant_matching_explicit_variant_passes() -> None:
+    """Specifying both a board and the matching variant is allowed."""
+    result = _detect_variant({CONF_BOARD: "rpipico2", CONF_VARIANT: VARIANT_RP2350})
+    assert result[CONF_BOARD] == "rpipico2"
+    assert result[CONF_VARIANT] == VARIANT_RP2350
+
+
+def test_detect_variant_mismatched_variant_raises() -> None:
+    """Board/variant mismatch must be rejected and name the offending board."""
+    with pytest.raises(
+        cv.Invalid, match=r"does not match the selected board 'rpipicow'"
+    ):
+        _detect_variant({CONF_BOARD: "rpipicow", CONF_VARIANT: VARIANT_RP2350})
+
+
+def test_detect_variant_unknown_board_without_variant_raises() -> None:
+    """Unknown board with no variant tells the user how to recover."""
+    with pytest.raises(cv.Invalid, match="please specify the chip variant"):
+        _detect_variant({CONF_BOARD: "not-a-real-board"})
+
+
+def test_detect_variant_unknown_board_with_variant_passes() -> None:
+    """Unknown board + explicit variant is accepted (with a warning)."""
+    result = _detect_variant(
+        {CONF_BOARD: "not-a-real-board", CONF_VARIANT: VARIANT_RP2040}
+    )
+    assert result[CONF_BOARD] == "not-a-real-board"
+    assert result[CONF_VARIANT] == VARIANT_RP2040