tests: drivers: uart: uart_elementary: Add runtime PM configuration

Add configuration that uses device runtime PM.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

tests/drivers/uart/uart_elementary/boards/nrf54h20dk_nrf54h20_cpuapp_dual_uart.overlay

@@ -30,6 +30,7 @@ dut: &uart135 {
 	pinctrl-1 = <&uart135_sleep_alt>;
 	pinctrl-names = "default", "sleep";
 	current-speed = <115200>;
+	zephyr,pm-device-runtime-auto;
 };
 
 &pinctrl {
@@ -59,4 +60,5 @@ dut_aux: &uart137 {
 	pinctrl-1 = <&uart137_sleep_alt>;
 	pinctrl-names = "default", "sleep";
 	current-speed = <115200>;
+	zephyr,pm-device-runtime-auto;
 };

tests/drivers/uart/uart_elementary/src/main.c

@@ -12,6 +12,7 @@
  */
 
 #include <zephyr/drivers/uart.h>
+#include <zephyr/pm/device_runtime.h>
 #include <zephyr/ztest.h>
 
 #if DT_NODE_EXISTS(DT_NODELABEL(dut))
@@ -268,15 +269,25 @@ ZTEST(uart_elementary, test_uart_dual_port_transmission)
 					      (void *)test_buffer_aux);
 	zassert_equal(err, 0, "Unexpected error when setting user data for UART1 callback %d", err);
 
+	if (IS_ENABLED(CONFIG_PM_DEVICE_RUNTIME)) {
+		int usage = pm_device_runtime_usage(uart_dev);
+		int usage_aux = pm_device_runtime_usage(uart_dev_aux);
+
+		zassert_equal(usage, 0);
+		zassert_equal(usage_aux, 0);
+		pm_device_runtime_get(uart_dev);
+		pm_device_runtime_get(uart_dev_aux);
+	}
+
 	uart_irq_err_enable(uart_dev);
 	uart_irq_err_enable(uart_dev_aux);
 
-	uart_irq_tx_enable(uart_dev);
-	uart_irq_tx_enable(uart_dev_aux);
-
 	uart_irq_rx_enable(uart_dev);
 	uart_irq_rx_enable(uart_dev_aux);
 
+	uart_irq_tx_enable(uart_dev);
+	uart_irq_tx_enable(uart_dev_aux);
+
 	/* wait for the tramission to finish (no polling is intentional) */
 	k_sleep(K_USEC(100 * SLEEP_TIME_US));
 
@@ -287,6 +298,17 @@ ZTEST(uart_elementary, test_uart_dual_port_transmission)
 	uart_irq_err_disable(uart_dev);
 	uart_irq_err_disable(uart_dev_aux);
 
+	if (IS_ENABLED(CONFIG_PM_DEVICE_RUNTIME)) {
+		pm_device_runtime_put(uart_dev);
+		pm_device_runtime_put(uart_dev_aux);
+
+		int usage = pm_device_runtime_usage(uart_dev);
+		int usage_aux = pm_device_runtime_usage(uart_dev_aux);
+
+		zassert_equal(usage, 0);
+		zassert_equal(usage_aux, 0);
+	}
+
 #if defined(CONFIG_SETUP_MISMATCH_TEST)
 	TC_PRINT("Mismatched configuration test\n");
 	zassert_not_equal(uart_error_counter + aux_uart_error_counter, 0,

tests/drivers/uart/uart_elementary/testcase.yaml

@@ -21,6 +21,15 @@ tests:
     extra_args: DTC_OVERLAY_FILE="boards/nrf54h20dk_nrf54h20_cpuapp_dual_uart.overlay"
     extra_configs:
       - CONFIG_DUAL_UART_TEST=y
+  drivers.uart.uart_elementary_dual_nrf54h.pm:
+    filter: CONFIG_SERIAL_SUPPORT_INTERRUPT
+    platform_allow:
+      - nrf54h20dk/nrf54h20/cpuapp
+    extra_args: DTC_OVERLAY_FILE="boards/nrf54h20dk_nrf54h20_cpuapp_dual_uart.overlay"
+    extra_configs:
+      - CONFIG_DUAL_UART_TEST=y
+      - CONFIG_PM_DEVICE=y
+      - CONFIG_PM_DEVICE_RUNTIME=y
   drivers.uart.uart_elementary_dual_setup_mismatch_nrf54h:
     filter: CONFIG_SERIAL_SUPPORT_INTERRUPT
     platform_allow: