tests: audio: dmic_util: test PDM_DT_IO_CFG_GET

Test the implementation of `PDM_DT_IO_CFG_GET`. Implemented as a
distinct test from `dmic_api` to allow running natively in CI.

Signed-off-by: Jordan Yates <jordan@embeint.com>

tests/drivers/audio/dmic_util/CMakeLists.txt

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(dmic_util)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

tests/drivers/audio/dmic_util/app.overlay

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2025 Embeint Pty Ltd
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	dmic_cfg0: dmic_cfg0 {
+		compatible = "zephyr,pdm-dmic";
+		clk-frequency-min = <1000000>;
+		clk-frequency-max = <2000000>;
+		clk-duty-cycle-min = <45>;
+		clk-duty-cycle-max = <55>;
+		channel-left;
+	};
+
+	dmic_cfg1: dmic_cfg1 {
+		compatible = "zephyr,pdm-dmic";
+		clk-frequency-min = <100000>;
+		clk-frequency-max = <400000>;
+		clk-duty-cycle-min = <40>;
+		clk-duty-cycle-max = <60>;
+		channel-right;
+	};
+
+	dmic_cfg2: dmic_cfg2 {
+		compatible = "zephyr,pdm-dmic";
+		clk-frequency-min = <150000>;
+		clk-frequency-max = <450000>;
+		clk-duty-cycle-min = <49>;
+		clk-duty-cycle-max = <51>;
+		channel-left;
+		channel-right;
+	};
+};

tests/drivers/audio/dmic_util/prj.conf

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+CONFIG_TEST=y
+CONFIG_ZTEST=y
+CONFIG_AUDIO=y
+CONFIG_AUDIO_DMIC=y

tests/drivers/audio/dmic_util/src/main.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2025 Embeint Pty Ltd
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/audio/dmic.h>
+#include <zephyr/ztest.h>
+
+ZTEST(dmic_util, test_io_cfg_get)
+{
+	const struct pdm_io_cfg cfg0 = PDM_DT_IO_CFG_GET(DT_NODELABEL(dmic_cfg0));
+	const struct pdm_io_cfg cfg1 = PDM_DT_IO_CFG_GET(DT_NODELABEL(dmic_cfg1));
+	const struct pdm_io_cfg cfg2 = PDM_DT_IO_CFG_GET(DT_NODELABEL(dmic_cfg2));
+
+	zassert_equal(1000000, cfg0.min_pdm_clk_freq);
+	zassert_equal(2000000, cfg0.max_pdm_clk_freq);
+	zassert_equal(45, cfg0.min_pdm_clk_dc);
+	zassert_equal(55, cfg0.max_pdm_clk_dc);
+
+	zassert_equal(100000, cfg1.min_pdm_clk_freq);
+	zassert_equal(400000, cfg1.max_pdm_clk_freq);
+	zassert_equal(40, cfg1.min_pdm_clk_dc);
+	zassert_equal(60, cfg1.max_pdm_clk_dc);
+
+	zassert_equal(150000, cfg2.min_pdm_clk_freq);
+	zassert_equal(450000, cfg2.max_pdm_clk_freq);
+	zassert_equal(49, cfg2.min_pdm_clk_dc);
+	zassert_equal(51, cfg2.max_pdm_clk_dc);
+}
+
+ZTEST(dmic_util, test_channel_query)
+{
+	zassert_true(PDM_DT_HAS_LEFT_CHANNEL(DT_NODELABEL(dmic_cfg0)));
+	zassert_false(PDM_DT_HAS_RIGHT_CHANNEL(DT_NODELABEL(dmic_cfg0)));
+
+	zassert_false(PDM_DT_HAS_LEFT_CHANNEL(DT_NODELABEL(dmic_cfg1)));
+	zassert_true(PDM_DT_HAS_RIGHT_CHANNEL(DT_NODELABEL(dmic_cfg1)));
+
+	zassert_true(PDM_DT_HAS_LEFT_CHANNEL(DT_NODELABEL(dmic_cfg2)));
+	zassert_true(PDM_DT_HAS_RIGHT_CHANNEL(DT_NODELABEL(dmic_cfg2)));
+}
+
+ZTEST_SUITE(dmic_util, NULL, NULL, NULL, NULL, NULL);

tests/drivers/audio/dmic_util/testcase.yaml

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+tests:
+  drivers.audio.dmic_util:
+    tags: dmic
+    harness: ztest
+    integration_platforms:
+      - native_sim