samples: nrf_rpc: ps_server: update fatal error trigger

1. Use /alias/fatal-error-trigger DTS property to select
   button (or GPIO pin) that triggers the fatal error.
2. Trigger fatal error from GPIO interrupt handler instead
   of DK_LIBRARY handler as the latter is run from the
   system workqueue context and we want the fatal error
   trigger to work even if the system work queue is stuck.

Signed-off-by: Damian Krolik <[email protected]>

Author: Damian-Nordic

samples/nrf_rpc/protocols_serialization/server/Kconfig

@@ -8,20 +8,21 @@ menu "Protocols serialization server"
 
 config NRF_PS_SERVER_FATAL_ERROR_TRIGGER
 	bool "Fatal error trigger"
-	select DK_LIBRARY
+	depends on $(dt_alias_enabled,fatal-error-trigger)
 	help
-	  Enables triggering a fatal error by pressing Button 1 on the development
-	  kit. This trigger allows for testing the feature of logging over RPC that
-	  provides an RPC client with access to the crash log stored in the retained
-	  RAM partition.
+	  Enables triggering a fatal error by pressing the button selected with
+	  "/aliases/fatal-error-trigger" DTS property. This feature can be used
+	  to generate a core dump into a flash/RRAM partition. The core dump can
+	  then be retrieved by the RPC client using the "Logging over RPC"
+	  library.
 
 config NRF_PS_SERVER_RPC_ALIVE_LED
 	bool "RPC alive LED"
 	default y
 	depends on $(dt_alias_enabled,rpc-alive-led)
 	help
-	  Turns on the LED selected with "/alias/rpc-alive-led" DTS property when
-	  the UART transport is alive and ready to receive nRF RPC packets.
+	  Turns on the LED selected with "/aliases/rpc-alive-led" DTS property
+	  when the UART transport is alive and ready to receive nRF RPC packets.
 
 module = NRF_PS_SERVER
 module-str = nrf_ps_server

samples/nrf_rpc/protocols_serialization/server/boards/nrf52840dk_nrf52840.overlay

@@ -10,6 +10,7 @@
 
 	aliases {
 		rpc-alive-led = &led0;
+		fatal-error-trigger = &button0;
 	};
 };
 

samples/nrf_rpc/protocols_serialization/server/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -10,6 +10,7 @@
 
 	aliases {
 		rpc-alive-led = &led0;
+		fatal-error-trigger = &button0;
 
 		/* delete all buttons except button0 to free GPIO pins assigned to uart21 below */
 		/delete-property/ sw1;

samples/nrf_rpc/protocols_serialization/server/src/fatal_error_trigger.c

@@ -4,25 +4,53 @@
  * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
  */
 
-#include <dk_buttons_and_leds.h>
-
+#include <zephyr/drivers/gpio.h>
 #include <zephyr/init.h>
-#include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
+#include <zephyr/sys/util_macro.h>
 
 LOG_MODULE_DECLARE(nrf_ps_server, CONFIG_NRF_PS_SERVER_LOG_LEVEL);
 
-static void button_handler(uint32_t button_state, uint32_t has_changed)
+const struct gpio_dt_spec gpio_pin = GPIO_DT_SPEC_GET(DT_ALIAS(fatal_error_trigger), gpios);
+static struct gpio_callback gpio_cb;
+
+static void trigger_handler(const struct device *port, struct gpio_callback *cb,
+			    gpio_port_pins_t pins)
 {
-	if (button_state & DK_BTN1_MSK) {
-		LOG_ERR("Fatal error button pressed - triggering k_oops");
-		k_oops();
-	}
+	ARG_UNUSED(port);
+	ARG_UNUSED(cb);
+	ARG_UNUSED(pins);
+
+	LOG_ERR("Fatal error button pressed - triggering k_oops");
+	k_oops();
 }
 
-static int button_handler_init(void)
+static int trigger_init(void)
 {
-	return dk_buttons_init(button_handler);
+	int rc;
+
+	if (!gpio_is_ready_dt(&gpio_pin)) {
+		return -ENODEV;
+	}
+
+	rc = gpio_pin_configure_dt(&gpio_pin, GPIO_INPUT);
+	if (rc) {
+		return rc;
+	}
+
+	gpio_init_callback(&gpio_cb, trigger_handler, BIT(gpio_pin.pin));
+
+	rc = gpio_add_callback_dt(&gpio_pin, &gpio_cb);
+	if (rc) {
+		return rc;
+	}
+
+	rc = gpio_pin_interrupt_configure_dt(&gpio_pin, GPIO_INT_EDGE_TO_ACTIVE);
+	if (rc) {
+		return rc;
+	}
+
+	return 0;
 }
 
-SYS_INIT(button_handler_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
+SYS_INIT(trigger_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);