boards: Add the Arduino Nano BLE 33

This commit adds the board definition files
needed to support the Arduino Nano BLE 33.
Tested: the following have been verified with
my logic analyzer.
* Serial peripherals (UART, I2C, SPI)
* USB
* RTC

Untested:
* PWM. In theory it should work but I don't
have a good enough logic analyzer to test this

* RTC's. The board doesn't have a backup battery.
The peripherals are enabled for modding another
battery in the device tree.

Signed-off-by: Jefferson Lee <jeffersonlee2000@gmail.com>

boards/arm/arduino_nano_33_ble/CMakeLists.txt

@@ -0,0 +1,13 @@
+# Copyright (c) 2020 Jefferson Lee.
+# SPDX-License-Identifier: Apache-2.0
+
+add_library(arduino_nano_33_ble_pins INTERFACE)
+target_include_directories(arduino_nano_33_ble_pins 
+        INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/inc/")
+
+
+if(CONFIG_BOARD_ARDUINO_NANO_33_BLE_INIT_SENSORS)
+  zephyr_library()
+  zephyr_library_sources("${CMAKE_CURRENT_SOURCE_DIR}/src/init_sensors.c")
+  target_link_libraries(${ZEPHYR_CURRENT_LIBRARY} PRIVATE arduino_nano_33_ble_pins)
+endif()

boards/arm/arduino_nano_33_ble/Kconfig.board

@@ -0,0 +1,20 @@
+# Copyright (c) 2020 Jefferson Lee.
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_ARDUINO_NANO_33_BLE
+	bool "Arduino Nano 33 BLE board"
+	depends on SOC_NRF52840_QIAA
+
+config BOARD_ARDUINO_NANO_33_BLE_EN_USB_CONSOLE
+	bool "Sends the console output over the USB port"
+	depends on BOARD_ARDUINO_NANO_33_BLE
+	select SERIAL
+	select USB
+	select CONSOLE
+	select PRINTK
+	select UART_INTERRUPT_DRIVEN
+	select USB_UART_CONSOLE
+
+config BOARD_ARDUINO_NANO_33_BLE_INIT_SENSORS
+	bool "Initializes the internal I2C sensors on the board"
+	depends on BOARD_ARDUINO_NANO_33_BLE

boards/arm/arduino_nano_33_ble/Kconfig.defconfig

@@ -0,0 +1,42 @@
+# Copyright (c) 2020 Jefferson Lee.
+# SPDX-License-Identifier: Apache-2.0
+
+if BOARD_ARDUINO_NANO_33_BLE
+config BOARD
+	default "arduino_nano_33_ble"
+
+if USB
+config USB_NRFX
+	default y
+config USB_DEVICE_STACK
+	default y
+endif # USB
+
+config BT_CTLR
+	default BT
+
+if I2C
+config I2C_NRFX
+	default y
+config NRFX_TWIM
+	default y
+config I2C_0
+	default y
+config I2C_1
+	default y
+config BOARD_ARDUINO_NANO_33_BLE_INIT_SENSORS
+	default y
+endif #I2C
+
+if SPI
+config SPI_NRFX
+	default y
+config NRFX_SPIM
+	default y
+config SPI_2
+	default y
+config SPI_2_NRF_SPIM
+	default y
+endif #SPI
+
+endif #board

boards/arm/arduino_nano_33_ble/arduino_nano_33_ble.dts

@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2020 Jefferson Lee
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+/dts-v1/;
+#include <nordic/nrf52840_qiaa.dtsi>
+
+/ {
+	model = "Arduino Nano 33 BLE (Sense)";
+	compatible = "arduino,arduino_nano_33_ble";
+
+	chosen {
+		zephyr,console = &uart0;
+		zephyr,shell-uart = &uart0;
+		zephyr,uart-mcumgr = &uart0;
+		zephyr,bt-mon-uart = &uart0;
+		zephyr,bt-c2h-uart = &uart0;
+		zephyr,sram = &sram0;
+		zephyr,flash = &flash0;
+		zephyr,code-partition = &code_partition;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+		led0: led_0 {
+			gpios = <&gpio0 24 0>;
+			label = "Red LED";
+		};
+	};
+
+	/* These aliases are provided for compatibility with samples */
+	aliases {
+		led0 = &led0;
+		spi = &spi2;
+	};
+};
+
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		code_partition: partition@10000 {
+			label = "code";
+			reg = <0x10000 0xf0000>;
+			read-only;
+		};
+	};
+};
+
+/*
+ * guide specifying pin numbers: https://docs.zephyrproject.org/latest/boards/arm/nrf52840dk_nrf52840/doc/index.html
+ * Given Pin PB.A:
+ * pin_no = B*32 + A
+ * ex. P1.0 => 32
+ */
+&adc {
+	status = "okay";
+};
+&uart0 {
+	compatible = "nordic,nrf-uart";
+	current-speed = <115200>;
+	status = "okay";
+	tx-pin = <35>; //P1.03
+	rx-pin = <42>; //P1.10
+};
+&i2c0 {
+	compatible = "nordic,nrf-twim";
+	status = "okay";
+	sda-pin = <31>; //P0.31
+	scl-pin = <2>; //P0.02
+};
+&i2c1 {
+	compatible = "nordic,nrf-twim";
+	status = "okay";
+	sda-pin = <14>; //P0.14
+	scl-pin = <15>; //P0.15
+};
+// we use SPI2 because SPI1/0 shares conflicts with I2C1/0
+&spi2 {
+	compatible = "nordic,nrf-spim";
+	status = "okay";
+	sck-pin = <13>; //P0.13
+	mosi-pin = <33>; //P1.01
+	miso-pin = <40>; //P1.08
+};
+&gpio0 {
+	status = "okay";
+};
+&gpio1 {
+	status = "okay";
+};
+&usbd {
+	compatible = "nordic,nrf-usbd";
+	status = "okay";
+};
+// All PWM's should be enaled
+&pwm0 {
+	status = "okay";
+};
+&pwm1 {
+	status = "okay";
+};
+&pwm2 {
+	status = "okay";
+};
+&pwm3 {
+	status = "okay";
+};
+/*
+ * NOTE: curiously, there is no PDM (microphone) interface in the
+ * nordic DTSI file.
+ * You'll need to use the nordic-specific PDM libraries.
+ */
+
+/*
+ * the following sets up the peripherals according to this file:
+ * https://github.com/arduino/ArduinoCore-nRF528x-mbedos/blob/19ddd214d255ca20b233eefa76662b360595c146/variants/ARDUINO_NANO33BLE/variant.cpp#L136
+ * The bootloader will conflict with RTC1
+ */
+&rtc1 {
+	status = "disabled";
+};

boards/arm/arduino_nano_33_ble/arduino_nano_33_ble.yaml

@@ -0,0 +1,20 @@
+identifier: arduino_nano_33_ble
+name: Arduino Nano 33 BLE (Sense)
+type: mcu
+arch: arm
+toolchain:
+  - zephyr
+  - gnuarmemb
+  - xtools
+supported:
+  - adc
+  - ble
+  - i2c
+  - ieee802154
+  - pwm
+  - serial
+  - spi
+  - uart
+  - usb_cdc
+  - usb_device
+  - watchdog

boards/arm/arduino_nano_33_ble/arduino_nano_33_ble_defconfig

@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_SOC_SERIES_NRF52X=y
+CONFIG_SOC_NRF52840_QIAA=y
+CONFIG_BOARD_ARDUINO_NANO_33_BLE=y
+
+# Enable MPU
+CONFIG_ARM_MPU=y
+CONFIG_HW_STACK_PROTECTION=y
+
+# enable peripherals
+CONFIG_GPIO=y
+CONFIG_SERIAL=y
+CONFIG_CONSOLE=y
+
+# enable flashing and linker options
+CONFIG_USE_DT_CODE_PARTITION=y
+
+# additional board options
+CONFIG_GPIO_AS_PINRESET=y

boards/arm/arduino_nano_33_ble/board.cmake

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: Apache-2.0
+
+include(${ZEPHYR_BASE}/boards/common/bossac.board.cmake)

boards/arm/arduino_nano_33_ble/doc/index.rst

@@ -0,0 +1,141 @@
+.. _arduino_nano_33_ble:
+
+Arduino Nano 33 BLE (Sense)
+#################################
+
+Overview
+********
+
+The Arduino Nano 33 BLE is designed around Nordic Semiconductor's
+nRF52840 ARM Cortex-M4F CPU. Arduino sells 2 variants of the board, the
+plain `BLE`_ type and the `BLE Sense`_ type. The "Sense" variant is distinguished by
+the inclusion of more sensors, but otherwise both variants are the same.
+
+.. image:: img/arduino_nano_33_ble_sense.png
+     :width: 500px
+     :align: center
+     :alt: Arduino Nano 33 BLE (Sense variant)
+
+The Sense variant of the board
+
+Hardware
+********
+
+Supported Features
+==================
+
+The package is configured to support the following hardware:
+
++-----------+------------+----------------------+
+| Interface | Controller | Driver/Component     |
++===========+============+======================+
+| ADC       | on-chip    | adc                  |
++-----------+------------+----------------------+
+| CLOCK     | on-chip    | clock_control        |
++-----------+------------+----------------------+
+| FLASH     | on-chip    | flash                |
++-----------+------------+----------------------+
+| GPIO      | on-chip    | gpio                 |
++-----------+------------+----------------------+
+| I2C0      | on-chip    | i2c                  |
++-----------+------------+----------------------+
+| I2C1      | on-chip    | i2c                  |
++-----------+------------+----------------------+
+| MPU       | on-chip    | arch/arm             |
++-----------+------------+----------------------+
+| NVIC      | on-chip    | arch/arm             |
++-----------+------------+----------------------+
+| PWM       | on-chip    | pwm                  |
++-----------+------------+----------------------+
+| RADIO     | on-chip    | Bluetooth,           |
+|           |            | ieee802154           |
++-----------+------------+----------------------+
+| RTC       | on-chip    | system clock         |
++-----------+------------+----------------------+
+| SPI       | on-chip    | spi                  |
++-----------+------------+----------------------+
+| UART      | on-chip    | serial               |
++-----------+------------+----------------------+
+| USB       | on-chip    | usb                  |
++-----------+------------+----------------------+
+| WDT       | on-chip    | watchdog             |
++-----------+------------+----------------------+
+
+Other hardware features are not supported by the Zephyr kernel.
+
+Notably, this includes the PDM (microphone) interface.
+
+Connections and IOs
+===================
+
+The `schematic`_ will tell you everything
+you need to know about the pins.
+
+A convinience header mapping the Arduino pin names to their
+Zephyr pin numbers can be found in :code:`arduino_nano_33_ble_pins.h`,
+if you link against the :code:`arduino_nano_33_ble_pins` CMake library.
+
+For your convience, two Kconfig options are added:
+
+#. :code:`BOARD_ARDUINO_NANO_33_BLE_INIT_SENSORS`: 
+    This configuration option enables the internal I2C sensors.
+#. :code:`BOARD_ARDUINO_NANO_33_BLE_EN_USB_CONSOLE`:
+    This configuration option enables the USB CDC subsystem and
+    the console, so that printk works.
+
+Programming and Debugging
+*************************
+
+This board requires the Arduino variant of bossac. You will not
+be able to flash with the bossac included with the zephyr-sdk, or
+using shumatech's mainline build.
+
+You can get this variant of bossac with one of two ways:
+
+#. Building the binary from the `Arduino source tree <https://github.com/arduino/BOSSA/tree/nrf>`_
+#. Downloading the Arduino IDE
+
+   #. Install the board support package within the IDE
+   #. Change your IDE preferences to provide verbose logging
+   #. Build and flash a sample application, and read the logs to figure out where Arduino stored bossac.
+
+Once you have a path to bossac, you can pass it as an argument to west:
+
+.. code-block:: bash
+
+   west flash --bossac="<path to the arduino version of bossac>"
+
+Flashing
+========
+
+Attach the board to your computer using the USB cable, and then
+
+   .. zephyr-app-commands::
+      :zephyr-app: samples/blinky
+      :board: arduino_nano_33_ble
+      :goals: build
+      :compact:
+
+Double-tap the RESET button on your board. Your board should disconnect, reconnect,
+and there should be a pulsing orange LED near the USB port.
+
+Then, you can flash the image using the above script.
+
+You should see the the red LED blink.
+
+References
+**********
+
+.. target-notes::
+
+.. _BLE:
+    https://store.arduino.cc/usa/nano-33-ble/
+
+.. _BLE SENSE:
+    https://store.arduino.cc/usa/nano-33-ble-sense/
+
+.. _pinouts:
+    https://learn.adafruit.com/introducing-the-adafruit-nrf52840-feather/pinouts
+
+.. _schematic:
+    https://content.arduino.cc/assets/NANO33BLE_V2.0_sch.pdf

boards/arm/arduino_nano_33_ble/inc/arduino_nano_33_ble.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2020 Jefferson Lee.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+#include "arduino_nano_33_ble_pins.h"
+
+/* this header-only library makes GPIO access a little more arduino-y. */
+#include <device.h>
+#include <drivers/gpio.h>
+struct arduino_gpio_t {
+	const struct device *gpios[2];
+};
+
+static inline void arduino_gpio_init(struct arduino_gpio_t *gpios)
+{
+	gpios->gpios[0] = device_get_binding("GPIO_0");
+	gpios->gpios[1] = device_get_binding("GPIO_1");
+}
+static inline int arduino_gpio_pinMode(struct arduino_gpio_t *gpios,
+						int pin, int mode)
+{
+	return gpio_pin_configure(gpios->gpios[pin / 32], pin % 32, mode);
+}
+static inline int arduino_gpio_digitalWrite(struct arduino_gpio_t *gpios,
+						int pin, int value)
+{
+	return gpio_pin_set(gpios->gpios[pin / 32], pin % 32, value);
+}
+static inline int arduino_gpio_digitalRead(struct arduino_gpio_t *gpios,
+						int pin)
+{
+	return gpio_pin_get(gpios->gpios[pin / 32], pin % 32);
+}

boards/arm/arduino_nano_33_ble/inc/arduino_nano_33_ble_pins.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2020 Jefferson Lee.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#pragma once
+/*
+ * This file will map the arduino pin names to their pin number
+ * Definitions are copied from here:
+ * https://github.com/arduino/ArduinoCore-nRF528x-mbedos/blob/6216632cc70271619ad43547c804dabb4afa4a00/variants/ARDUINO_NANO33BLE/variant.cpp#L77
+ * (in the array g_APinDescription)
+ * The pin number is derived using the formula:
+ * Given GPIO pin PB.A
+ * Pin Number = B*32 + A
+ * ex. P1.3 => 35
+ */
+
+
+#define ARDUINO_D0_TX (32 * 1 + 3)                      /* P1.3 */
+#define ARDUINO_D1_RX (32 * 1 + 10)                     /* P1.10 */
+#define ARDUINO_D2 (32 * 1 + 11)                        /* P1.11 */
+#define ARDUINO_D3 (32 * 1 + 12)                        /* P1.12 */
+#define ARDUINO_D4 (32 * 1 + 15)                        /* P1.15 */
+#define ARDUINO_D5 (32 * 1 + 13)                        /* P1.13 */
+#define ARDUINO_D6 (32 * 1 + 14)                        /* P1.14 */
+#define ARDUINO_D7 (32 * 0 + 23)                        /* P0.23 */
+
+#define ARDUINO_D8 (32 * 0 + 21)                        /* P0.21 */
+#define ARDUINO_D9 (32 * 0 + 27)                        /* P0.27 */
+#define ARDUINO_D10 (32 * 1 + 2)                        /* P1.2 */
+#define ARDUINO_D11_MOSI (32 * 1 + 1)                   /* P1.1 */
+#define ARDUINO_D12_MISO (32 * 1 + 8)                   /* P1.8 */
+#define ARDUINO_D13_SCK (32 * 0 + 13)                   /* P0.13 */
+
+#define ARDUINO_A0 (32 * 0 + 24)                        /* P0.24 */
+#define ARDUINO_A1 (32 * 0 + 5)                         /* P0.5 */
+#define ARDUINO_A2 (32 * 0 + 30)                        /* P0.30 */
+#define ARDUINO_A3 (32 * 0 + 29)                        /* P0.29 */
+#define ARDUINO_A4_SDA (32 * 0 + 31)                    /* P0.31 */
+#define ARDUINO_A5_SCL (32 * 0 + 2)                     /* P0.2 */
+#define ARDUINO_A6 (32 * 0 + 28)                        /* P0.28 */
+#define ARDUINO_A7 (32 * 0 + 3)                         /* P0.3 */
+
+#define ARDUINO_LEDR (32 * 0 + 24)                      /* P0.24 */
+#define ARDUINO_LEDG (32 * 0 + 16)                      /* P0.16 */
+#define ARDUINO_LEDB (32 * 0 + 6)                       /* P0.6 */
+#define ARDUINO_LEDPWR (32 * 1 + 9)                     /* P1.9 */
+
+#define ARDUINO_INT_APDS (32 * 0 + 19)                  /* P0.19 */
+
+#define ARDUINO_PDM_PWR (32 * 0 + 17)                   /* P0.17 */
+#define ARDUINO_PDM_CLK (32 * 0 + 26)                   /* P0.26 */
+#define ARDUINO_PDM_DIN (32 * 0 + 25)                   /* P0.25 */
+
+#define ARDUINO_SDA1 (32 * 0 + 14)                      /* P0.14 */
+#define ARDUINO_SCL1 (32 * 0 + 15)                      /* P0.15 */
+#define ARDUINO_INTERNAL_I2C_PULLUP (32 * 1 + 0)        /* P1.0 */
+#define ARDUINO_INTERNAL_VDD_ENV_ENABLE (32 * 0 + 22)   /* P0.22 */

boards/arm/arduino_nano_33_ble/src/init_sensors.c

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2020 Jefferson Lee.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <init.h>
+#include <arduino_nano_33_ble.h>
+
+/*
+ * this method roughly follows the steps here:
+ * https://github.com/arduino/ArduinoCore-nRF528x-mbedos/blob/6216632cc70271619ad43547c804dabb4afa4a00/variants/ARDUINO_NANO33BLE/variant.cpp#L136
+ */
+
+static int board_internal_sensors_init(const struct device *dev)
+{
+	ARG_UNUSED(dev);
+	struct arduino_gpio_t gpios;
+
+	arduino_gpio_init(&gpios);
+
+	arduino_gpio_pinMode(&gpios, ARDUINO_LEDPWR, GPIO_OUTPUT);
+	arduino_gpio_digitalWrite(&gpios, ARDUINO_LEDPWR, 1);
+
+	CoreDebug->DEMCR = 0;
+	NRF_CLOCK->TRACECONFIG = 0;
+
+	/*
+	 * Arduino uses software to disable RTC1,
+	 * but I disabled it using DeviceTree
+	 */
+	/* nrf_rtc_event_disable(NRF_RTC1, NRF_RTC_INT_COMPARE0_MASK); */
+	/* nrf_rtc_int_disable(NRF_RTC1, NRF_RTC_INT_COMPARE0_MASK); */
+
+	NRF_PWM_Type * PWM[] = {
+		NRF_PWM0, NRF_PWM1, NRF_PWM2, NRF_PWM3
+	};
+
+	for (unsigned int i = 0; i < (ARRAY_SIZE(PWM)); i++) {
+		PWM[i]->ENABLE = 0;
+		PWM[i]->PSEL.OUT[0] = 0xFFFFFFFFUL;
+	}
+
+	/*
+	 * the PCB designers decided to use GPIO's
+	 * as power pins for the internal sensors
+	 */
+	arduino_gpio_pinMode(&gpios, ARDUINO_INTERNAL_VDD_ENV_ENABLE, GPIO_OUTPUT);
+	arduino_gpio_pinMode(&gpios, ARDUINO_INTERNAL_I2C_PULLUP, GPIO_OUTPUT);
+	arduino_gpio_digitalWrite(&gpios, ARDUINO_INTERNAL_VDD_ENV_ENABLE, 1);
+	arduino_gpio_digitalWrite(&gpios, ARDUINO_INTERNAL_I2C_PULLUP, 1);
+	return 0;
+}
+SYS_INIT(board_internal_sensors_init, PRE_KERNEL_1, 32);

tests/drivers/adc/adc_api/src/test_adc.c

@@ -47,7 +47,8 @@
 	defined(CONFIG_BOARD_ADAFRUIT_FEATHER_NRF52840)	|| \
 	defined(CONFIG_BOARD_RUUVI_RUUVITAG) || \
 	defined(CONFIG_BOARD_BT510) || \
-	defined(CONFIG_BOARD_PINNACLE_100_DVK)
+	defined(CONFIG_BOARD_PINNACLE_100_DVK) || \
+	defined(CONFIG_BOARD_ARDUINO_NANO_33_BLE)
 
 #include <hal/nrf_saadc.h>
 #define ADC_DEVICE_NAME		DT_LABEL(DT_INST(0, nordic_nrf_saadc))