[nrf fromtree] tests: drivers: adc: add nRF54L20 configuration

Added the test configuration for nRF54L20 for the following tests:
- adc_api
- adc_error_cases

Signed-off-by: Rafał Kuźnia <[email protected]>

Signed-off-by: Sebastian Głąb <[email protected]>
(cherry picked from commit f78742f)

Author: nordic-segl

drivers/adc/adc_nrfx_saadc.c

@@ -31,7 +31,7 @@ static const uint8_t saadc_psels[NRF_SAADC_AIN7 + 1] = {
 	[NRF_SAADC_AIN6] = NRF_PIN_PORT_TO_PIN_NUMBER(6U, 1),
 	[NRF_SAADC_AIN7] = NRF_PIN_PORT_TO_PIN_NUMBER(7U, 1),
 };
-#elif defined(CONFIG_SOC_NRF54L05) || defined(CONFIG_SOC_NRF54L10) || defined(CONFIG_SOC_NRF54L15)
+#elif defined(CONFIG_SOC_COMPATIBLE_NRF54LX)
 static const uint32_t saadc_psels[NRF_SAADC_DVDD + 1] = {
 	[NRF_SAADC_AIN0] = NRF_PIN_PORT_TO_PIN_NUMBER(4U, 1),
 	[NRF_SAADC_AIN1] = NRF_PIN_PORT_TO_PIN_NUMBER(5U, 1),

tests/drivers/adc/adc_api/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -0,0 +1,44 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ */
+
+/ {
+	zephyr,user {
+		io-channels = <&adc 0>, <&adc 1> , <&adc 2>;
+	};
+};
+
+&adc {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "okay";
+
+	channel@0 {
+		reg = <0>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 10)>;
+		zephyr,input-positive = <NRF_SAADC_AIN1>;
+		zephyr,resolution = <10>;
+	};
+
+	channel@1 {
+		reg = <1>;
+		zephyr,gain = "ADC_GAIN_1_4";
+		zephyr,reference = "ADC_REF_EXTERNAL0";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,input-positive = <NRF_SAADC_AIN4>;
+		zephyr,resolution = <12>;
+	};
+
+	channel@2 {
+		reg = <2>;
+		zephyr,gain = "ADC_GAIN_2_3";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 10)>;
+		zephyr,input-positive = <NRF_SAADC_AIN2>;
+		zephyr,resolution = <10>;
+	};
+};

tests/drivers/adc/adc_error_cases/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ */
+
+/ {
+	aliases {
+		adc = &adc;
+	};
+};
+
+&adc {
+	status = "okay";
+};

tests/drivers/adc/adc_error_cases/testcase.yaml

@@ -4,4 +4,5 @@ tests:
     platform_allow:
       - nrf52840dk/nrf52840
       - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54h20dk/nrf54h20/cpuapp