boards: Add initial support for the Raspberry Pi Pico 2

The Raspberry Pi Pico 2 is Raspberry Pi's first board fitted with their
RP2350A SoC.

This adds a minimal board definition, sufficient to build and run
`samples/hello_world` and `samples/basic/blinky` on the board. Images
can be run on the target using OpenOCD. Raspberry Pi's `picotool` can
create a UF2 binary, which ensures that errata RP2350-E10 is avoided
e.g.

```
> picotool uf2 convert build\rpi_pico2\hello_world\zephyr\zephyr.elf \
    build\rpi_pico2\hello_world\zephyr\zephyr.uf2 \
    --family rp2350-arm-s --abs-block`
```

Raspberry Pi Pico 2 is a low-cost, high-performance microcontroller
board with flexible digital interfaces. Key features include:

- RP2350A microcontroller chip designed by Raspberry Pi in the United
  Kingdom
- Dual Cortex-M33 or Hazard3 processors at up to 150MHz
- 520KB of SRAM, and 4MB of on-board flash memory
- USB 1.1 with device and host support
- Low-power sleep and dormant modes
- Drag-and-drop programming using mass storage over USB
- 26x multi-function GPIO pins including 3 that can be used for ADC
- 2x SPI, 2x I2C, 2x UART, 3x 12-bit 500ksps Analogue to Digital
  Converter (ADC), 24x controllable PWM channels
- 2x Timer with 4 alarms, 1x AON Timer
- Temperature sensor
- 3x Programmable IO (PIO) blocks, 12 state machines total for custom
  peripheral support
    - Flexible, user-programmable high-speed IO
    - Can emulate interfaces such as SD Card and VGA

The Raspberry Pi Pico 2 comes as a castellated module which allows
soldering direct to carrier boards.

Only enable timer 0 for now. Timer 1 won't work correctly until the
rpi_pico HAL has picked up the fix for `hardware_alarm_irq_handler`. See
https://github.com/raspberrypi/pico-sdk/pull/1949 .

Added some documentation for the board itself (mostly aiming to refer to
canonical sources of information rather duplicate). Add entries in the
release notes where applicable.

boards/raspberrypi/rpi_pico2/doc/img/rpi_pico2.webp is a cropped and
compressed version of https://www.raspberrypi.com/documentation/microcontrollers/images/pico-2.png
which is released under the CC-BY-SA-4.0 license. See https://github.com/raspberrypi/documentation/blob/develop/LICENSE.md

Signed-off-by: Andrew Featherstone <andrew.featherstone@gmail.com>
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>

boards/raspberrypi/common/rpi_pico-led.dtsi

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2021 Yonatan Schachter
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Pico and Pico 2 boards (but not Pico W) have a common LED placement. */
+/ {
+	leds {
+		compatible = "gpio-leds";
+		led0: led_0 {
+			gpios = <&gpio0 25 GPIO_ACTIVE_HIGH>;
+			label = "LED";
+		};
+	};
+
+	pwm_leds {
+		compatible = "pwm-leds";
+		status = "disabled";
+		pwm_led0: pwm_led_0 {
+			pwms = <&pwm 9 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
+			label = "PWM_LED";
+		};
+	};
+
+	aliases {
+		led0 = &led0;
+		pwm-led0 = &pwm_led0;
+	};
+};

boards/raspberrypi/common/rpi_pico-pinctrl-common.dtsi

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2021, Yonatan Schachter
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* The Pico and Pico 2 are pin compatible. */
+&pinctrl {
+	uart0_default: uart0_default {
+		group1 {
+			pinmux = <UART0_TX_P0>;
+		};
+		group2 {
+			pinmux = <UART0_RX_P1>;
+			input-enable;
+		};
+	};
+
+	i2c0_default: i2c0_default {
+		group1 {
+			pinmux = <I2C0_SDA_P4>, <I2C0_SCL_P5>;
+			input-enable;
+			input-schmitt-enable;
+		};
+	};
+
+	i2c1_default: i2c1_default {
+		group1 {
+			pinmux = <I2C1_SDA_P6>, <I2C1_SCL_P7>;
+			input-enable;
+			input-schmitt-enable;
+		};
+	};
+
+	spi0_default: spi0_default {
+		group1 {
+			pinmux = <SPI0_CSN_P17>, <SPI0_SCK_P18>, <SPI0_TX_P19>;
+		};
+		group2 {
+			pinmux = <SPI0_RX_P16>;
+			input-enable;
+		};
+	};
+
+	pwm_ch4b_default: pwm_ch4b_default {
+		group1 {
+			pinmux = <PWM_4B_P25>;
+		};
+	};
+
+	adc_default: adc_default {
+		group1 {
+			pinmux = <ADC_CH0_P26>, <ADC_CH1_P27>, <ADC_CH2_P28>, <ADC_CH3_P29>;
+			input-enable;
+		};
+	};
+};

boards/raspberrypi/rpi_pico/doc/index.rst

@@ -96,6 +96,8 @@ hardware features:
      - :kconfig:option:`CONFIG_SPI`
      - :dtcompatible:`raspberrypi,pico-spi-pio`
 
+.. _rpi_pico_pin_mapping:
+
 Pin Mapping
 ===========
 

boards/raspberrypi/rpi_pico/rpi_pico-pinctrl.dtsi

@@ -5,53 +5,4 @@
 
 #include <zephyr/dt-bindings/pinctrl/rpi-pico-rp2040-pinctrl.h>
 
-&pinctrl {
-	uart0_default: uart0_default {
-		group1 {
-			pinmux = <UART0_TX_P0>;
-		};
-		group2 {
-			pinmux = <UART0_RX_P1>;
-			input-enable;
-		};
-	};
-
-	i2c0_default: i2c0_default {
-		group1 {
-			pinmux = <I2C0_SDA_P4>, <I2C0_SCL_P5>;
-			input-enable;
-			input-schmitt-enable;
-		};
-	};
-
-	i2c1_default: i2c1_default {
-		group1 {
-			pinmux = <I2C1_SDA_P6>, <I2C1_SCL_P7>;
-			input-enable;
-			input-schmitt-enable;
-		};
-	};
-
-	spi0_default: spi0_default {
-		group1 {
-			pinmux = <SPI0_CSN_P17>, <SPI0_SCK_P18>, <SPI0_TX_P19>;
-		};
-		group2 {
-			pinmux = <SPI0_RX_P16>;
-			input-enable;
-		};
-	};
-
-	pwm_ch4b_default: pwm_ch4b_default {
-		group1 {
-			pinmux = <PWM_4B_P25>;
-		};
-	};
-
-	adc_default: adc_default {
-		group1 {
-			pinmux = <ADC_CH0_P26>, <ADC_CH1_P27>, <ADC_CH2_P28>, <ADC_CH3_P29>;
-			input-enable;
-		};
-	};
-};
+#include "../common/rpi_pico-pinctrl-common.dtsi"

boards/raspberrypi/rpi_pico/rpi_pico.dts

@@ -7,27 +7,4 @@
 /dts-v1/;
 
 #include "rpi_pico-common.dtsi"
-
-/ {
-	leds {
-		compatible = "gpio-leds";
-		led0: led_0 {
-			gpios = <&gpio0 25 GPIO_ACTIVE_HIGH>;
-			label = "LED";
-		};
-	};
-
-	pwm_leds {
-		compatible = "pwm-leds";
-		status = "disabled";
-		pwm_led0: pwm_led_0 {
-			pwms = <&pwm 9 PWM_MSEC(20) PWM_POLARITY_NORMAL>;
-			label = "PWM_LED";
-		};
-	};
-
-	aliases {
-		led0 = &led0;
-		pwm-led0 = &pwm_led0;
-	};
-};
+#include "../common/rpi_pico-led.dtsi"

boards/raspberrypi/rpi_pico2/Kconfig.defconfig

@@ -0,0 +1,9 @@
+# Copyright (c) 2024 Andrew Featherstone
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_RPI_PICO2
+
+config USB_SELF_POWERED
+	default n
+
+endif # BOARD_RPI_PICO2

boards/raspberrypi/rpi_pico2/Kconfig.rpi_pico2

@@ -0,0 +1,5 @@
+# Copyright (c) 2024 Andrew Featherstone
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_RPI_PICO2
+	select SOC_RP2350A_M33 if BOARD_RPI_PICO2_RP2350A_M33

boards/raspberrypi/rpi_pico2/board.yml

@@ -0,0 +1,6 @@
+board:
+  name: rpi_pico2
+  full_name: Raspberry Pi Pico 2
+  vendor: raspberrypi
+  socs:
+  - name: rp2350a

boards/raspberrypi/rpi_pico2/doc/index.rst

@@ -0,0 +1,87 @@
+.. zephyr:board:: rpi_pico2
+
+Overview
+********
+
+The Raspberry Pi Pico 2 is the second-generation product in the Raspberry Pi
+Pico family. From the `Raspberry Pi website <https://www.raspberrypi.com/documentation/microcontrollers/pico-series.html>`_ is referred to as Pico 2.
+
+There are many limitations of the board currently. Including but not limited to:
+- The Zephyr build only supports configuring the RP2350A with the Cortex-M33 cores.
+- As with the Pico 1, there's no support for running any code on the second core.
+
+Hardware
+********
+
+- Dual Cortex-M33 or Hazard3 processors at up to 150MHz
+- 520KB of SRAM, and 4MB of on-board flash memory
+- USB 1.1 with device and host support
+- Low-power sleep and dormant modes
+- Drag-and-drop programming using mass storage over USB
+- 26 multi-function GPIO pins including 3 that can be used for ADC
+- 2 SPI, 2 I2C, 2 UART, 3 12-bit 500ksps Analogue to Digital - Converter (ADC), 24 controllable PWM channels
+- 2 Timer with 4 alarms, 1 AON Timer
+- Temperature sensor
+- 3 Programmable IO (PIO) blocks, 12 state machines total for custom peripheral support
+
+  - Flexible, user-programmable high-speed IO
+  - Can emulate interfaces such as SD Card and VGA
+
+Supported Features
+==================
+
+The ``rpi_pico2/rp2350a/m33`` board target supports the following
+hardware features:
+
+.. list-table::
+   :header-rows: 1
+
+   * - Peripheral
+     - Kconfig option
+     - Devicetree compatible
+   * - NVIC
+     - N/A
+     - :dtcompatible:`arm,v8m-nvic`
+   * - ADC
+     - :kconfig:option:`CONFIG_ADC`
+     - :dtcompatible:`raspberrypi,pico-adc`
+   * - Clock controller
+     - :kconfig:option:`CONFIG_CLOCK_CONTROL`
+     - :dtcompatible:`raspberrypi,pico-clock-controller`
+   * - Counter
+     - :kconfig:option:`CONFIG_COUNTER`
+     - :dtcompatible:`raspberrypi,pico-timer`
+   * - GPIO
+     - :kconfig:option:`CONFIG_GPIO`
+     - :dtcompatible:`raspberrypi,pico-gpio`
+   * - HWINFO
+     - :kconfig:option:`CONFIG_HWINFO`
+     - N/A
+   * - I2C
+     - :kconfig:option:`CONFIG_I2C`
+     - :dtcompatible:`snps,designware-i2c`
+   * - PWM
+     - :kconfig:option:`CONFIG_PWM`
+     - :dtcompatible:`raspberrypi,pico-pwm`
+   * - SPI
+     - :kconfig:option:`CONFIG_SPI`
+     - :dtcompatible:`raspberrypi,pico-spi`
+   * - UART
+     - :kconfig:option:`CONFIG_SERIAL`
+     - :dtcompatible:`raspberrypi,pico-uart`
+
+Connections and IOs
+===================
+
+The default pin mapping is unchanged from the Pico 1 (see :ref:`rpi_pico_pin_mapping`).
+
+Programming and Debugging
+*************************
+
+As with the Pico 1, the SWD interface can be used to program and debug the
+device, e.g. using OpenOCD with the `Raspberry Pi Debug Probe <https://www.raspberrypi.com/documentation/microcontrollers/debug-probe.html>`_ .
+
+References
+**********
+
+.. target-notes::

boards/raspberrypi/rpi_pico2/rpi_pico2-pinctrl.dtsi

@@ -0,0 +1,8 @@
+/*
+ * Copyright (c) 2024, Andrew Featherstone
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/pinctrl/rpi-pico-rp2350a-pinctrl.h>
+
+#include "../common/rpi_pico-pinctrl-common.dtsi"

boards/raspberrypi/rpi_pico2/rpi_pico2.dtsi

@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2024 Andrew Featherstone
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <freq.h>
+
+#include <zephyr/dt-bindings/i2c/i2c.h>
+#include <zephyr/dt-bindings/pwm/pwm.h>
+
+#include "rpi_pico2-pinctrl.dtsi"
+#include "../common/rpi_pico-led.dtsi"
+
+/ {
+	chosen {
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+		zephyr,console = &uart0;
+		zephyr,shell-uart = &uart0;
+		zephyr,code-partition = &code_partition;
+	};
+
+	aliases {
+		watchdog0 = &wdt0;
+	};
+
+	pico_header: connector {
+		compatible = "raspberrypi,pico-header";
+		#gpio-cells = <2>;
+		gpio-map-mask = <0xffffffff 0xffffffc0>;
+		gpio-map-pass-thru = <0 0x3f>;
+		gpio-map = <0 0 &gpio0 0 0>,	/* GP0 */
+			<1 0 &gpio0 1 0>,	/* GP1 */
+			<2 0 &gpio0 2 0>,	/* GP2 */
+			<3 0 &gpio0 3 0>,	/* GP3 */
+			<4 0 &gpio0 4 0>,	/* GP4 */
+			<5 0 &gpio0 5 0>,	/* GP5 */
+			<6 0 &gpio0 6 0>,	/* GP6 */
+			<7 0 &gpio0 7 0>,	/* GP7 */
+			<8 0 &gpio0 8 0>,	/* GP8 */
+			<9 0 &gpio0 9 0>,	/* GP9 */
+			<10 0 &gpio0 10 0>,	/* GP10 */
+			<11 0 &gpio0 11 0>,	/* GP11 */
+			<12 0 &gpio0 12 0>,	/* GP12 */
+			<13 0 &gpio0 13 0>,	/* GP13 */
+			<14 0 &gpio0 14 0>,	/* GP14 */
+			<15 0 &gpio0 15 0>,	/* GP15 */
+			<16 0 &gpio0 16 0>,	/* GP16 */
+			<17 0 &gpio0 17 0>,	/* GP17 */
+			<18 0 &gpio0 18 0>,	/* GP18 */
+			<19 0 &gpio0 19 0>,	/* GP19 */
+			<20 0 &gpio0 20 0>,	/* GP20 */
+			<21 0 &gpio0 21 0>,	/* GP21 */
+			<22 0 &gpio0 22 0>,	/* GP22 */
+			<26 0 &gpio0 26 0>,	/* GP26 */
+			<27 0 &gpio0 27 0>,	/* GP27 */
+			<28 0 &gpio0 28 0>;	/* GP28 */
+	};
+};
+
+&flash0 {
+	reg = <0x10000000 DT_SIZE_M(4)>;
+
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/* Reserved memory for an image definition block. The block is much
+		 * smaller than 256 bytes, but in practice the linker places the vector
+		 * table at a much larger alignment offset.
+		 */
+		image_def: partition@0 {
+			label = "image_def";
+			reg = <0x00000000 0x100>;
+			read-only;
+		};
+
+		/*
+		 * Usable flash. Starts at 0x100, after the image definition block.
+		 * The partition size is 4MB minus the 0x100 bytes taken by the
+		 * image definition.
+		 */
+		code_partition: partition@100 {
+			label = "code-partition";
+			reg = <0x100 (DT_SIZE_M(4) - 0x100)>;
+			read-only;
+		};
+	};
+};
+
+&uart0 {
+	current-speed = <115200>;
+	status = "okay";
+	pinctrl-0 = <&uart0_default>;
+	pinctrl-names = "default";
+};
+
+&gpio0 {
+	status = "okay";
+};
+
+&spi0 {
+	clock-frequency = <DT_FREQ_M(8)>;
+	pinctrl-0 = <&spi0_default>;
+	pinctrl-names = "default";
+};
+
+&i2c0 {
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+	pinctrl-0 = <&i2c0_default>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&i2c1 {
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+	pinctrl-0 = <&i2c1_default>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&adc {
+	pinctrl-0 = <&adc_default>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&pwm {
+	pinctrl-0 = <&pwm_ch4b_default>;
+	pinctrl-names = "default";
+	divider-int-0 = <255>;
+};
+
+&timer0 {
+	status = "okay";
+};
+
+zephyr_udc0: &usbd {
+	status = "okay";
+};
+
+pico_serial: &uart0 {};

boards/raspberrypi/rpi_pico2/rpi_pico2_rp2350a_m33.dts

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2024 Andrew Featherstone
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+
+/* The build system assumes that there's a cpucluster-specific file.
+ *
+ * This file provides composition of the device tree:
+ * 1. The common features of the SoC
+ * 2. Core-specific configuration.
+ * 3. Board-specific configuration.
+ */
+#include <raspberrypi/rpi_pico/rp2350a.dtsi>
+#include <raspberrypi/rpi_pico/m33.dtsi>
+
+/* there's nothing specific to the Cortex-M33 cores vs the (not yet
+ * implemented) Hazard3 cores.
+ */
+#include "rpi_pico2.dtsi"

boards/raspberrypi/rpi_pico2/rpi_pico2_rp2350a_m33.yaml

@@ -0,0 +1,20 @@
+identifier: rpi_pico2/rp2350a/m33
+name: Raspberry Pi Pico 2 (Cortex-M33)
+type: mcu
+arch: arm
+flash: 4096
+ram: 520
+toolchain:
+  - zephyr
+  - gnuarmemb
+  - xtools
+supported:
+  - adc
+  - clock
+  - counter
+  - gpio
+  - hwinfo
+  - i2c
+  - pwm
+  - spi
+  - uart

boards/raspberrypi/rpi_pico2/rpi_pico2_rp2350a_m33_defconfig

@@ -0,0 +1,12 @@
+# This configuration is orthogonal to whether the Cortex-M33 or Hazard3 cores
+# are in use, but Zephyr does not support providing a qualifier-agnostic
+# _defconfig file.
+CONFIG_CLOCK_CONTROL=y
+CONFIG_CONSOLE=y
+CONFIG_GPIO=y
+CONFIG_RESET=y
+CONFIG_SERIAL=y
+CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=150000000
+CONFIG_UART_CONSOLE=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_USE_DT_CODE_PARTITION=y