[nrf fromlist] tests: boards: nrf: i2c: add twi variant

Currently only TWIM peripheral is verified against TWIS.
Add new test variant to verify nRF52 TWI peripheral as well.

Upstream PR #: 100805

Signed-off-by: Nikodem Kastelik <nikodem.kastelik@nordicsemi.no>
(cherry picked from commit 06ae9be)

Author: nika-nordic

tests/boards/nrf/i2c/i2c_slave/boards/nrf52840dk_nrf52840.overlay

@@ -3,69 +3,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-/*
- * Two loopbacks are required:
- * P1.01 - P1.02
- * P1.03 - P1.04
- */
-
-/ {
-	aliases {
-		i2c-slave = &i2c1;
-	};
-};
-
-&pinctrl {
-	i2c0_default_alt: i2c0_default_alt {
-		group1 {
-			psels = <NRF_PSEL(TWIM_SDA, 1, 1)>,
-				<NRF_PSEL(TWIM_SCL, 1, 3)>;
-		};
-	};
-
-	i2c0_sleep_alt: i2c0_sleep_alt {
-		group1 {
-			psels = <NRF_PSEL(TWIM_SDA, 1, 1)>,
-				<NRF_PSEL(TWIM_SCL, 1, 3)>;
-			low-power-enable;
-		};
-	};
-
-	i2c1_default_alt: i2c1_default_alt {
-		group1 {
-			psels = <NRF_PSEL(TWIM_SDA, 1, 2)>,
-				<NRF_PSEL(TWIM_SCL, 1, 4)>;
-			bias-pull-up;
-		};
-	};
-
-	i2c1_sleep_alt: i2c1_sleep_alt {
-		group1 {
-			psels = <NRF_PSEL(TWIM_SDA, 1, 2)>,
-				<NRF_PSEL(TWIM_SCL, 1, 4)>;
-			low-power-enable;
-		};
-	};
-};
+#include "nrf52840dk_nrf52840_common.overlay"
 
 dut_twim: &i2c0 {
 	compatible = "nordic,nrf-twim";
-	status = "okay";
-	pinctrl-0 = <&i2c0_default_alt>;
-	pinctrl-1 = <&i2c0_sleep_alt>;
-	pinctrl-names = "default", "sleep";
-	clock-frequency = <I2C_BITRATE_STANDARD>;
-
-	sensor: sensor@54 {
-		reg = <0x54>;
-	};
-};
-
-dut_twis: &i2c1 {
-	compatible = "nordic,nrf-twis";
-	status = "okay";
-	pinctrl-0 = <&i2c1_default_alt>;
-	pinctrl-1 = <&i2c1_sleep_alt>;
-	pinctrl-names = "default", "sleep";
-	clock-frequency = <I2C_BITRATE_STANDARD>;
 };

tests/boards/nrf/i2c/i2c_slave/boards/nrf52840dk_nrf52840_common.overlay

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * Two loopbacks are required:
+ * P1.01 - P1.02
+ * P1.03 - P1.04
+ */
+
+/ {
+	aliases {
+		i2c-slave = &i2c1;
+	};
+};
+
+&pinctrl {
+	i2c0_default_alt: i2c0_default_alt {
+		group1 {
+			psels = <NRF_PSEL(TWIM_SDA, 1, 1)>,
+				<NRF_PSEL(TWIM_SCL, 1, 3)>;
+		};
+	};
+
+	i2c0_sleep_alt: i2c0_sleep_alt {
+		group1 {
+			psels = <NRF_PSEL(TWIM_SDA, 1, 1)>,
+				<NRF_PSEL(TWIM_SCL, 1, 3)>;
+			low-power-enable;
+		};
+	};
+
+	i2c1_default_alt: i2c1_default_alt {
+		group1 {
+			psels = <NRF_PSEL(TWIS_SDA, 1, 2)>,
+				<NRF_PSEL(TWIS_SCL, 1, 4)>;
+			bias-pull-up;
+		};
+	};
+
+	i2c1_sleep_alt: i2c1_sleep_alt {
+		group1 {
+			psels = <NRF_PSEL(TWIS_SDA, 1, 2)>,
+				<NRF_PSEL(TWIS_SCL, 1, 4)>;
+			low-power-enable;
+		};
+	};
+};
+
+&i2c0 {
+	status = "okay";
+	pinctrl-0 = <&i2c0_default_alt>;
+	pinctrl-1 = <&i2c0_sleep_alt>;
+	pinctrl-names = "default", "sleep";
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+
+	sensor: sensor@54 {
+		reg = <0x54>;
+	};
+};
+
+dut_twis: &i2c1 {
+	compatible = "nordic,nrf-twis";
+	status = "okay";
+	pinctrl-0 = <&i2c1_default_alt>;
+	pinctrl-1 = <&i2c1_sleep_alt>;
+	pinctrl-names = "default", "sleep";
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+};

tests/boards/nrf/i2c/i2c_slave/boards/nrf52840dk_nrf52840_twi.overlay

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "nrf52840dk_nrf52840_common.overlay"
+
+&i2c0 {
+	compatible = "nordic,nrf-twi";
+};

tests/boards/nrf/i2c/i2c_slave/testcase.yaml

@@ -24,6 +24,12 @@ tests:
       - nrf54h20dk/nrf54h20/cpuppr
       - nrf54l15dk/nrf54l15/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
+  boards.nrf.i2c.i2c_slave.twi:
+    platform_allow:
+      - nrf52840dk/nrf52840
+    integration_platforms:
+      - nrf52840dk/nrf52840
+    extra_args: DTC_OVERLAY_FILE="boards/nrf52840dk_nrf52840_twi.overlay"
   boards.nrf.i2c.i2c_slave.fast:
     platform_allow:
       - nrf52840dk/nrf52840