[nrf fromlist] tests: drivers: comparator: add gpio_loopback test suite

Add test suite which uses GPIO loopback to produce a "very low" and
"very high" voltage at the positive input of the comparator using the
output of a GPIO. The negative input is set to a voltage between the
high and low output voltages of the GPIO using whichever internal
reference is available to the comparator.

Upstream PR: zephyrproject-rtos/zephyr#79724

Signed-off-by: Bjarki Arge Andreasen <[email protected]>

tests/drivers/comparator/gpio_loopback/CMakeLists.txt

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+# Copyright (c) 2024 Nordic Semiconductor
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(comparator_gpio_loopback)
+
+target_sources(app PRIVATE src/test.c)

tests/drivers/comparator/gpio_loopback/boards/frdm_ke15z.overlay

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+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <nxp/kinetis/MKE17Z256VLL7-pinctrl.h>
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
+/*
+ * PTA1 looped back to PTA0
+ */
+
+/ {
+	aliases {
+		test-comp = &cmp0;
+	};
+
+	zephyr,user {
+		test-gpios = <&gpioa 1 GPIO_ACTIVE_HIGH>;
+	};
+};
+
+&gpioa {
+	status = "okay";
+};
+
+&pinctrl {
+	cmp0_default: cmp0_default {
+		group0 {
+			pinmux = <ACMP0_IN0_PTA0>;
+			drive-strength = "high";
+		};
+	};
+};
+
+&cmp0 {
+	pinctrl-0 = <&cmp0_default>;
+	pinctrl-names = "default";
+	status = "okay";
+
+	positive-mux-input = "IN0";
+	positive-port-input = "MUX";
+	negative-mux-input = "IN0";
+	negative-port-input = "DAC";
+
+	dac-vref-source = "VIN1";
+	dac-value = <128>;
+	dac-enable;
+};

tests/drivers/comparator/gpio_loopback/boards/nrf5340dk_nrf5340_cpuapp.overlay

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+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
+/*
+ * P0.05 looped back to P0.04
+ */
+
+/ {
+	aliases {
+		test-comp = &comp;
+	};
+
+	zephyr,user {
+		test-gpios = <&gpio0 5 GPIO_ACTIVE_HIGH>;
+	};
+};
+
+&gpio0{
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

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+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
+/*
+ * P1.03 looped back to P1.02
+ */
+
+/ {
+	aliases {
+		test-comp = &comp;
+	};
+
+	zephyr,user {
+		test-gpios = <&gpio1 3 GPIO_ACTIVE_HIGH>;
+	};
+};
+
+&gpio1 {
+	status = "okay";
+};
+
+/* Temporary workaround to reserve P1.03 for cpuapp */
+&led1 {
+	gpios = < &gpio1 0x3 0x0 >;
+};
+
+/* Temporary workaround to reserve P1.02 for cpuapp */
+&led2 {
+	gpios = < &gpio1 0x2 0x0 >;
+};

tests/drivers/comparator/gpio_loopback/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
+/*
+ * P1.10 looped back to P1.11
+ */
+
+/ {
+	aliases {
+		test-comp = &comp;
+	};
+
+	zephyr,user {
+		test-gpios = <&gpio1 10 GPIO_ACTIVE_HIGH>;
+	};
+};
+
+&gpio1 {
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/boards/nrf54l15pdk_nrf54l15_cpuapp.overlay

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+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/gpio/gpio.h>
+
+/*
+ * P1.10 looped back to P1.11
+ */
+
+/ {
+	aliases {
+		test-comp = &comp;
+	};
+
+	zephyr,user {
+		test-gpios = <&gpio1 10 GPIO_ACTIVE_HIGH>;
+	};
+};
+
+&gpio1 {
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/prj.conf

@@ -0,0 +1,6 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_ZTEST=y
+CONFIG_GPIO=y
+CONFIG_COMPARATOR=y

tests/drivers/comparator/gpio_loopback/snippets/nrf_comp/boards/nrf5340dk_nrf5340_cpuapp.overlay

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+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&comp {
+	main-mode = "SE";
+	psel = "AIN0"; /* P0.04 */
+	refsel = "VDD";
+	sp-mode = "HIGH";
+	th-up = <34>;
+	th-down = <30>;
+	isource = "DISABLED";
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/snippets/nrf_comp/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&comp {
+	main-mode = "SE";
+	psel = "AIN2"; /* P1.02 */
+	refsel = "INT_1V2";
+	sp-mode = "HIGH";
+	th-up = <63>;
+	th-down = <59>;
+	isource = "DISABLED";
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/snippets/nrf_comp/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&comp {
+	main-mode = "SE";
+	psel = "AIN4"; /* P1.11 */
+	refsel = "INT_1V2";
+	sp-mode = "HIGH";
+	th-up = <63>;
+	th-down = <59>;
+	isource = "DISABLED";
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/snippets/nrf_comp/snippet.yml

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+# Copyright 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+name: gpio_loopback_nrf_comp
+
+boards:
+  nrf54h20dk/nrf54h20/cpuapp:
+    append:
+      EXTRA_DTC_OVERLAY_FILE: boards/nrf54h20dk_nrf54h20_cpuapp.overlay
+  nrf54l15dk/nrf54l15/cpuapp:
+    append:
+      EXTRA_DTC_OVERLAY_FILE: boards/nrf54l15dk_nrf54l15_cpuapp.overlay
+  nrf5340dk/nrf5340/cpuapp:
+    append:
+      EXTRA_DTC_OVERLAY_FILE: boards/nrf5340dk_nrf5340_cpuapp.overlay

tests/drivers/comparator/gpio_loopback/snippets/nrf_lpcomp/boards/nrf5340dk_nrf5340_cpuapp.overlay

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+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&comp {
+	compatible = "nordic,nrf-lpcomp";
+	psel = "AIN0"; /* P0.04 */
+	refsel = "VDD_4_8";
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/snippets/nrf_lpcomp/boards/nrf54h20dk_nrf54h20_cpuapp.overlay

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&comp {
+	compatible = "nordic,nrf-lpcomp";
+	psel = "AIN2"; /* P1.02 */
+	refsel = "VDD_4_8";
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/snippets/nrf_lpcomp/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&comp {
+	compatible = "nordic,nrf-lpcomp";
+	psel = "AIN4"; /* P1.11 */
+	refsel = "VDD_4_8";
+	status = "okay";
+};

tests/drivers/comparator/gpio_loopback/snippets/nrf_lpcomp/snippet.yml

@@ -0,0 +1,15 @@
+# Copyright 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+name: gpio_loopback_nrf_lpcomp
+
+boards:
+  nrf54h20dk/nrf54h20/cpuapp:
+    append:
+      EXTRA_DTC_OVERLAY_FILE: boards/nrf54h20dk_nrf54h20_cpuapp.overlay
+  nrf54l15dk/nrf54l15/cpuapp:
+    append:
+      EXTRA_DTC_OVERLAY_FILE: boards/nrf54l15dk_nrf54l15_cpuapp.overlay
+  nrf5340dk/nrf5340/cpuapp:
+    append:
+      EXTRA_DTC_OVERLAY_FILE: boards/nrf5340dk_nrf5340_cpuapp.overlay