dts: arm: rpi_pico: add SIO block and mailbox device

Add a mailbox (Interprocessor FIFO) node to the RP2040 and RP2350 device
trees and a SIO block to hold this and any other future SIO peripherals.

This also includes an additional `zephyr,mbox-ipm` node that handles the
mailbox for core to core messaging.

The device is enabled for the Raspberry Pico Pi 2.

Signed-off-by: Ricardo Cañuelo Navarro <[email protected]>

Author: r-c-n

boards/raspberrypi/rpi_pico2/rpi_pico2.dtsi

@@ -19,6 +19,7 @@
 		zephyr,flash-controller = &qmi;
 		zephyr,console = &uart0;
 		zephyr,shell-uart = &uart0;
+		zephyr,ipc = &ipc;
 	};
 
 	aliases {

boards/raspberrypi/rpi_pico2/rpi_pico2_rp2350a_m33_defconfig

@@ -11,3 +11,4 @@ CONFIG_SERIAL=y
 CONFIG_UART_CONSOLE=y
 CONFIG_UART_INTERRUPT_DRIVEN=y
 CONFIG_USE_DT_CODE_PARTITION=y
+CONFIG_MBOX=y

dts/arm/raspberrypi/rpi_pico/rp2040.dtsi

@@ -435,6 +435,34 @@
 			alarms-count = <1>;
 			status = "disabled";
 		};
+
+		sio: sio@d0000000 {
+			compatible = "raspberrypi,pico-sio";
+			reg = <0xd0000000 0x180>;
+
+			mbox: mbox {
+				compatible = "raspberrypi,pico-mbox";
+				interrupts = <15 RPI_PICO_DEFAULT_IRQ_PRIORITY>,
+					     <16 RPI_PICO_DEFAULT_IRQ_PRIORITY>;
+				interrupt-names = "mbox0", "mbox1";
+				fifo-depth = <8>;
+				#mbox-cells = <0>;
+				status = "okay";
+			};
+		};
+
+		ipc: ipc {
+			/*
+			 * The zephyr,mbox-ipm driver expects two mailbox
+			 * channels, but the mailbox block in the RP2040
+			 * implements a single instance per core. Point the
+			 * two driver channels to the same single mbox.
+			 */
+			compatible = "zephyr,mbox-ipm";
+			mboxes = <&mbox>, <&mbox>;
+			mbox-names = "tx", "rx";
+			status = "okay";
+		};
 	};
 
 	pinctrl: pin-controller {

dts/arm/raspberrypi/rpi_pico/rp2350.dtsi

@@ -453,6 +453,33 @@
 			interrupt-names = "irq0", "irq1";
 			status = "disabled";
 		};
+
+		sio: sio@d0000000 {
+			compatible = "raspberrypi,pico-sio";
+			reg = <0xd0000000 DT_SIZE_K(80)>;
+
+			mbox: mbox {
+				compatible = "raspberrypi,pico-mbox";
+				interrupts = <25 RPI_PICO_DEFAULT_IRQ_PRIORITY>;
+				interrupt-names = "mbox0";
+				fifo-depth = <4>;
+				#mbox-cells = <0>;
+				status = "okay";
+			};
+		};
+
+		ipc: ipc {
+			/*
+			 * The zephyr,mbox-ipm driver expects two mailbox
+			 * channels, but the mailbox block in the RP2350
+			 * implements a single instance per core. Point the
+			 * two driver channels to the same single mbox.
+			 */
+			compatible = "zephyr,mbox-ipm";
+			mboxes = <&mbox>, <&mbox>;
+			mbox-names = "tx", "rx";
+			status = "okay";
+		};
 	};
 
 	pinctrl: pin-controller {