zephyr-cp: dynamic I2C0 and UARTE UART0 on the CLUE

The upstream board fixes I2C0 to SCL/SDA with the legacy TWI driver,
which the board-bus rule no longer allows on a board that uses iobroker.
Make it a dynamic TWIM instance; the onboard sensors on SCL/SDA have no
devicetree nodes, so it doesn't need to be fixed.

The upstream board also uses the legacy UART driver for UART0, the
CLUE's only UART instance. It can't be de-initialized, so after the
first busio.UART was released, no UART could be created again. Use
UARTE.

Add a console.overlay, so a CONSOLE=1 build puts the Zephyr console on
TX/RX, as on the Feathers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: dhalbert

ports/zephyr-cp/boards/adafruit/clue_nrf52840_zephyr/board.overlay

@@ -1,6 +1,8 @@
 /* Partition layout is owned by the mcuboot fork
  * (dts/adafruit/adafruit_clue_nrf52840.dtsi) and applied to this image by
  * sysbuild. This overlay only adds board/app config. */
+/* No Zephyr console by default, so TX/RX are free for busio.UART. A CONSOLE=1
+ * build puts the console back on UART0 (console.overlay). */
 / {
 	chosen {
 		/delete-property/ zephyr,console;
@@ -15,11 +17,12 @@
 	/delete-node/ board_cdc_acm_uart;
 };
 
-// UART0, I2C1 and SPI3 are enabled with all pins disconnected and marked
-// zephyr,deferred-init so nothing is claimed at boot: the iobroker
+// UART0, I2C0, I2C1 and SPI3 are enabled with all pins disconnected and
+// marked zephyr,deferred-init so nothing is claimed at boot: the iobroker
 // initializes and routes a device to arbitrary pins when a busio object is
-// constructed, and de-initializes it on release. (I2C0 is the fixed sensor
-// bus, SPI2 the fixed display bus, and QSPI the fixed external flash.)
+// constructed, and de-initializes it on release. (SPI2 is the fixed display
+// bus and QSPI the fixed external flash. The onboard sensors are on SCL/SDA
+// but have no devicetree nodes, so I2C0 does not need to be fixed.)
 //
 // See "nRF serial instances" in internal-modules/iobroker/README.md for how
 // the instances are shared and allocated.
@@ -44,6 +47,20 @@
 		};
 	};
 
+	i2c0_dyn_default: i2c0_dyn_default {
+		group1 {
+			psels = <NRF_PSEL_DISCONNECTED(TWIM_SDA)>,
+				<NRF_PSEL_DISCONNECTED(TWIM_SCL)>;
+		};
+	};
+
+	i2c0_dyn_sleep: i2c0_dyn_sleep {
+		group1 {
+			psels = <NRF_PSEL_DISCONNECTED(TWIM_SDA)>,
+				<NRF_PSEL_DISCONNECTED(TWIM_SCL)>;
+		};
+	};
+
 	i2c1_dyn_default: i2c1_dyn_default {
 		group1 {
 			psels = <NRF_PSEL_DISCONNECTED(TWIM_SDA)>,
@@ -147,7 +164,11 @@
 	};
 };
 
+// The upstream board uses the legacy UART driver for UART0, which can't be
+// de-initialized, so iobroker could not route it again once it was released.
+// Instead, use the UARTE driver, which can be deinited.
 &uart0 {
+	compatible = "nordic,nrf-uarte";
 	status = "okay";
 	zephyr,deferred-init;
 	current-speed = <115200>;
@@ -156,6 +177,17 @@
 	pinctrl-names = "default", "sleep";
 };
 
+// The upstream board fixes I2C0 to SCL/SDA with the legacy TWI driver. Use
+// TWIM like I2C1 so iobroker can route it.
+&i2c0 {
+	compatible = "nordic,nrf-twim";
+	status = "okay";
+	zephyr,deferred-init;
+	pinctrl-0 = <&i2c0_dyn_default>;
+	pinctrl-1 = <&i2c0_dyn_sleep>;
+	pinctrl-names = "default", "sleep";
+};
+
 &i2c1 {
 	status = "okay";
 	zephyr,deferred-init;

ports/zephyr-cp/boards/adafruit/clue_nrf52840_zephyr/console.overlay

@@ -0,0 +1,18 @@
+/* Applied after board.overlay in CONSOLE=1 and DEBUG=1 builds: the Zephyr
+ * console on UART0, fixed to the TX/RX pins. TX/RX are then not available to
+ * busio.UART. */
+/ {
+	chosen {
+		zephyr,console = &uart0;
+		zephyr,shell-uart = &uart0;
+		zephyr,uart-mcumgr = &uart0;
+		zephyr,bt-mon-uart = &uart0;
+		zephyr,bt-c2h-uart = &uart0;
+	};
+};
+
+&uart0 {
+	/delete-property/ zephyr,deferred-init;
+	pinctrl-0 = <&uart0_default>;
+	pinctrl-1 = <&uart0_sleep>;
+};