boards: waveshare: rp2040_plus: Initial support

boards/waveshare/rp2040_plus/Kconfig

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+# Copyright (c) 2025 David Schneider
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_RP2040_PLUS
+	select RP2_FLASH_W25Q080

boards/waveshare/rp2040_plus/Kconfig.defconfig

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+# Copyright (c) 2025 David Schneider
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_RP2040_PLUS
+
+if I2C_DW
+
+config I2C_DW_CLOCK_SPEED
+	default 125
+
+endif # I2C_DW
+
+endif # BOARD_RP2040_PLUS

boards/waveshare/rp2040_plus/Kconfig.rp2040_plus

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+# Copyright (c) 2025 David Schneider
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_RP2040_PLUS
+	select SOC_RP2040

boards/waveshare/rp2040_plus/board.cmake

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+# SPDX-License-Identifier: Apache-2.0
+
+board_runner_args(uf2 "--board-id=RPI-RP2")
+
+include(${ZEPHYR_BASE}/boards/common/uf2.board.cmake)

boards/waveshare/rp2040_plus/board.yml

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+board:
+  name: rp2040_plus
+  full_name: RP2040-Plus
+  vendor: waveshare
+  socs:
+  - name: rp2040

boards/waveshare/rp2040_plus/doc/index.rst

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+.. zephyr:board:: rp2040_plus
+
+Overview
+********
+
+RP2040-Plus, a low-cost, high-performance Pico-like MCU board based on Raspberry Pi microcontroller RP2040
+including a battery charger.
+
+Hardware
+********
+- Dual core Arm Cortex-M0+ processor running up to 133MHz
+- 264KB on-chip SRAM
+- 4MB/16MB on-board QSPI flash with XIP capabilities
+- 26 GPIO pins
+- 3 Analog inputs
+- 2 UART peripherals
+- 2 SPI controllers
+- 2 I2C controllers
+- 16 PWM channels
+- USB 1.1 controller (host/device)
+- 8 Programmable I/O (PIO) for custom peripherals
+- On-board LED
+- 1 Watchdog timer peripheral
+- on-board battery charger
+
+
+Supported Features
+==================
+
+.. zephyr:board-supported-hw::
+
+Pin Mapping
+===========
+
+The peripherals of the RP2040 SoC can be routed to various pins on the board.
+The configuration of these routes can be modified through DTS. Please refer to
+the datasheet to see the possible routings for each peripheral.
+
+.. figure:: img/rp2040_plus-details.webp
+     :align: center
+     :alt: Waveshare RP2040-Plus pinout overview
+
+Default Zephyr Peripheral Mapping:
+----------------------------------
+
+.. rst-class:: rst-columns
+
+- UART0_TX : P0
+- UART0_RX : P1
+- I2C0_SDA : P4
+- I2C0_SCL : P5
+- I2C1_SDA : P6
+- I2C1_SCL : P7
+- SPI0_RX : P16
+- SPI0_CSN : P17
+- SPI0_SCK : P18
+- SPI0_TX : P19
+- ADC_CH0 : P26
+- ADC_CH1 : P27
+- ADC_CH2 : P28
+
+Programming and Debugging
+*************************
+
+.. zephyr:board-supported-runners::
+
+Flashing
+========
+
+Using UF2
+---------
+
+Here is an example of building the sample for driving the built-in led.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/basic/blinky
+   :board: rp2040_plus
+   :goals: build
+   :compact:
+
+You must flash the RP2040-Plus with an UF2 file. One option is to use West (Zephyr’s meta-tool). To enter the UF2 flashing mode just keep the ``BOOT`` button pressed while you connect the USB port, it will appear on the host as a mass storage device. In alternative with the board already connected via USB you can keep the ``RESET`` button pressed, press and release ``BOOT``, release ``RESET``. At this point you can flash the image file by running:
+
+.. code-block:: bash
+
+  west flash
+
+Alternatively, you can locate the generated :file:`build/zephyr/zephyr.uf2` file and simply drag-and-drop to the device after entering the UF2 flashing mode.
+
+References
+**********
+
+- `Official Documentation`_
+
+.. _Official Documentation: https://www.waveshare.com/wiki/RP2040-Plus

boards/waveshare/rp2040_plus/rp2040_plus-pinctrl.dtsi

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+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <dt-bindings/pinctrl/rpi-pico-rp2040-pinctrl.h>
+#include <dt-bindings/i2c/i2c.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;
+		};
+	};
+};

boards/waveshare/rp2040_plus/rp2040_plus.dts

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+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/dts-v1/;
+
+#include <freq.h>
+#include <zephyr/dt-bindings/pwm/pwm.h>
+#include <raspberrypi/rpi_pico/rp2040.dtsi>
+
+#include "rp2040_plus-pinctrl.dtsi"
+
+/ {
+	chosen {
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+		zephyr,flash-controller = &ssi;
+		zephyr,console = &uart0;
+		zephyr,shell-uart = &uart0;
+		zephyr,code-partition = &code_partition;
+	};
+
+	aliases {
+		rtc = &rtc;
+		watchdog0 = &wdt0;
+		led0 = &led0;
+		pwm-led0 = &pwm_led0;
+	};
+
+	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 */
+	};
+
+	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";
+		};
+	};
+
+	vbatt: vbatt {
+		compatible = "voltage-divider";
+		io-channels = <&adc 3>;
+		output-ohms = <100000>;
+		full-ohms = <(200000 + 100000)>;
+	};
+};
+
+&flash0 {
+	reg = <0x10000000 DT_SIZE_M(4)>;
+
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/* Reserved memory for the second stage bootloader */
+		second_stage_bootloader: partition@0 {
+			label = "second_stage_bootloader";
+			reg = <0x00000000 0x100>;
+			read-only;
+		};
+
+		/*
+		 * Usable flash. Starts at 0x100, after the bootloader. The partition
+		 * size is 4MB minus the 0x100 bytes taken by the bootloader.
+		 */
+		code_partition: partition@100 {
+			label = "code-partition";
+			reg = <0x100 (DT_SIZE_M(4) - 0x100)>;
+			read-only;
+		};
+	};
+};
+
+&uart0 {
+	status = "okay";
+	current-speed = <115200>;
+	pinctrl-0 = <&uart0_default>;
+	pinctrl-names = "default";
+};
+
+&i2c0 {
+	status = "okay";
+	pinctrl-0 = <&i2c0_default>;
+	pinctrl-names = "default";
+	clock-frequency = <I2C_BITRATE_STANDARD>;
+};
+
+&i2c1 {
+	pinctrl-0 = <&i2c1_default>;
+	pinctrl-names = "default";
+	clock-frequency = <I2C_BITRATE_FAST>;
+};
+
+&spi0 {
+	clock-frequency = <DT_FREQ_M(8)>;
+	status = "okay";
+	pinctrl-0 = <&spi0_default>;
+	pinctrl-names = "default";
+};
+
+&timer {
+	status = "okay";
+};
+
+&wdt0 {
+	status = "okay";
+};
+
+&gpio0 {
+	status = "okay";
+};
+
+&rtc {
+	clocks = <&clocks RPI_PICO_CLKID_CLK_RTC>;
+	status = "okay";
+};
+
+&adc {
+	status = "okay";
+	pinctrl-0 = <&adc_default>;
+	pinctrl-names = "default";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	channel@3 {
+		reg = <3>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
+
+	channel@4 {
+		reg = <4>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_INTERNAL";
+		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
+		zephyr,resolution = <12>;
+	};
+};
+
+zephyr_udc0: &usbd {
+	status = "okay";
+};
+
+&pwm {
+	pinctrl-0 = <&pwm_ch4b_default>;
+	pinctrl-names = "default";
+};
+
+&vreg {
+	regulator-always-on;
+	regulator-allowed-modes = <REGULATOR_RPI_PICO_MODE_NORMAL>;
+};
+
+pico_spi: &spi0 {};
+pico_i2c0: &i2c0 {};
+pico_i2c1: &i2c1 {};
+pico_serial: &uart0 {};