samples: mbox: Fix APP belboard channel on nrf9251dk

Regression after nrfconnect@49a7b3a

Bell 18 shall be rang by cpurad. Since, there is no Radio core
on nrf9251dk, bell 18 was disabled.

MOBX samples and tests were using bell 18 to communicate
with PPR core. Fix overlays by using dedicated bell 13 instead.

Signed-off-by: Sebastian Głąb <sebastian.glab@nordicsemi.no>

Author: nordic-segl

samples/zephyr/drivers/mbox/boards/nrf9251dk_nrf9251_cpuapp.overlay

@@ -6,7 +6,7 @@
 / {
 	mbox-consumer {
 		compatible = "vnd,mbox-consumer";
-		mboxes = <&cpuppr_vevif 15>, <&cpuapp_bellboard 18>;
+		mboxes = <&cpuppr_vevif 15>, <&cpuapp_bellboard 13>;
 		mbox-names = "tx", "rx";
 	};
 };

samples/zephyr/drivers/mbox/remote/boards/nrf9251dk_nrf9251_cpuppr.overlay

@@ -6,7 +6,7 @@
 / {
 	mbox-consumer {
 		compatible = "vnd,mbox-consumer";
-		mboxes = <&cpuppr_vevif 15>, <&cpuapp_bellboard 18>;
+		mboxes = <&cpuppr_vevif 15>, <&cpuapp_bellboard 13>;
 		mbox-names = "rx", "tx";
 	};
 };

samples/zephyr/drivers/mbox/sample.yaml

@@ -74,7 +74,7 @@ tests:
       ordered: false
       regex:
         - "Ping \\(on channel 15\\)"
-        - "Pong \\(on channel 18\\)"
+        - "Pong \\(on channel 13\\)"
 
   nrf.extended.sample.drivers.mbox.nrf9251_app_flpr:
     platform_allow:

tests/zephyr/drivers/mbox/mbox_error_cases/boards/nrf9251dk_nrf9251_cpuapp.overlay

@@ -7,14 +7,22 @@
 	mbox-consumer {
 		compatible = "vnd,mbox-consumer";
 		mboxes = <&cpuppr_vevif 15>, <&cpuppr_vevif 32>,
-			 <&cpuapp_bellboard 18>, <&cpuapp_bellboard 32>;
+			 <&cpuapp_bellboard 13>, <&cpuapp_bellboard 32>;
 		mbox-names = "remote_valid", "remote_incorrect",
 			     "local_valid", "local_incorrect";
 	};
 };
 
 &cpuapp_bellboard {
 	status = "okay";
+	/* The following bells on this bellboard are rang by these cores
+	 *  - Bell 0: cpusec
+	 *  - Bell 6: cpusys
+	 *  - Bell 13: cpuppr
+	 *  - Bell 14: cpuflpr
+	 *  - Bells 24, 25, 29, 31: cpucell
+	 */
+	nordic,interrupt-mapping = <0xa3006041 0>;
 };
 
 &cpuppr_vevif {

tests/zephyr/drivers/mbox/mbox_error_cases/boards/nrf9251dk_nrf9251_cpuppr.overlay

@@ -6,7 +6,7 @@
 / {
 	mbox-consumer {
 		compatible = "vnd,mbox-consumer";
-		mboxes = <&cpuapp_bellboard 18>, <&cpuapp_bellboard 32>,
+		mboxes = <&cpuapp_bellboard 13>, <&cpuapp_bellboard 32>,
 			 <&cpuppr_vevif 15>, <&cpuppr_vevif 32>;
 		mbox-names = "remote_valid", "remote_incorrect",
 			     "local_valid", "local_incorrect";