add board definition for Metro M0

boards/metro_m0/board.mk

@@ -0,0 +1,5 @@
+CHIP = samd21
+LDSCRIPT = samd21j18
+
+DEFINES += \
+  -D__SAMD21G18A__ \

boards/metro_m0/pins.h

@@ -0,0 +1,65 @@
+#pragma once
+
+#include "hal_gpio.h"
+#include "spi.h"
+#include "i2c.h"
+#include "uart.h"
+
+// Analog pins
+HAL_GPIO_PIN(A0,   A, 2)
+HAL_GPIO_PIN(A1,   B, 8)
+HAL_GPIO_PIN(A2,   B, 9)
+HAL_GPIO_PIN(A3,   A, 4)
+HAL_GPIO_PIN(A4,   A, 5)
+HAL_GPIO_PIN(A5,   B, 2)
+
+// Digital pins
+HAL_GPIO_PIN(D0,   A, 11) // also RX below
+HAL_GPIO_PIN(D1,   A, 10) // also TX below
+HAL_GPIO_PIN(D2,   A, 14) // also TX below
+HAL_GPIO_PIN(D3,   A,  9) // also TX below
+HAL_GPIO_PIN(D4,   A,  8) // SDCS on Adalogger, RST on radio
+HAL_GPIO_PIN(D5,   A, 15)
+HAL_GPIO_PIN(D6,   A, 20)
+HAL_GPIO_PIN(D7,   A, 21)
+HAL_GPIO_PIN(D8,   A,  6)
+HAL_GPIO_PIN(D9,   A,  7)
+HAL_GPIO_PIN(D10,  A, 18)
+HAL_GPIO_PIN(D11,  A, 16)
+HAL_GPIO_PIN(D12,  A, 19)
+HAL_GPIO_PIN(D13,  A, 17)
+HAL_GPIO_PIN(LED,  A, 17)
+
+// SPI
+HAL_GPIO_PIN(SCK,  B, 11)
+HAL_GPIO_PIN(MOSI, B, 10)
+HAL_GPIO_PIN(MISO, A, 12)
+#define SPI_SERCOM 4
+#define SPI_SERCOM_DOPO SPI_DOPO_2_SCK_3
+#define SPI_SERCOM_DIPO SPI_DIPO_0
+
+// I2C
+HAL_GPIO_PIN(SDA,  A, 22)
+HAL_GPIO_PIN(SCL,  A, 23)
+#define I2C_SERCOM 5
+
+// UART
+HAL_GPIO_PIN(TX,   A, 10)
+HAL_GPIO_PIN(RX,   A, 11)
+#define UART_SERCOM 0
+#define UART_SERCOM_TXPO UART_TXPO_2
+#define UART_SERCOM_RXPO UART_RXPO_3
+
+// SPI Flash
+HAL_GPIO_PIN(FLASH_SCK,  B, 23)
+HAL_GPIO_PIN(FLASH_MOSI, B, 22)
+HAL_GPIO_PIN(FLASH_MISO, B,  3)
+HAL_GPIO_PIN(FLASH_CS,   A, 13)
+#define FLASH_SPI_SERCOM 5
+#define FLASH_SPI_SERCOM_DOPO SPI_DOPO_2_SCK_3
+#define FLASH_SPI_SERCOM_DIPO SPI_DIPO_1
+
+// Bonus LEDs!
+HAL_GPIO_PIN(NEOPIXEL, A, 30)
+HAL_GPIO_PIN(TX_LED,   A, 27)
+HAL_GPIO_PIN(RX_LED,   A, 31)