Board support for Adafruit Gemma M0

Makefile

@@ -558,6 +558,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=trinket-m0          examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=gemma-m0            examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-express examples/blinky1
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=circuitplay-bluefruit examples/blinky1

src/machine/board_gemma-m0.go

@@ -0,0 +1,96 @@
+//go:build sam && atsamd21 && gemma_m0
+
+package machine
+
+// Used to reset into bootloader.
+const resetMagicValue = 0xf01669ef
+
+// GPIO Pins.
+const (
+	D0  = PA04 // SERCOM0/PAD[0]
+	D1  = PA02
+	D2  = PA05 // SERCOM0/PAD[1]
+	D3  = PA00 // DotStar LED: SERCOM1/PAD[0]: APA102/MOSI
+	D4  = PA01 // DotStar LED: SERCOM1/PAD[1]: APA102/SCK
+	D11 = PA30 // Flash Access: SERCOM1/PAD[2]
+	D12 = PA31 // Flash Access: SERCOM1/PAD[3]
+	D13 = PA23 // LED: SERCOM3/PAD[1] SERCOM5/PAD[1]
+)
+
+// Analog pins.
+const (
+	A0 = D1
+	A1 = D2
+	A2 = D0
+)
+
+const (
+	LED = PA23
+)
+
+// USBCDC pins.
+const (
+	USBCDC_DM_PIN = PA24
+	USBCDC_DP_PIN = PA25
+)
+
+// UART0 pins.
+const (
+	UART_TX_PIN = PA04 // TX: SERCOM0/PAD[0]
+	UART_RX_PIN = PA05 // RX: SERCOM0/PAD[1]
+)
+
+// UART0s on the Gemma M0.
+var UART0 = &sercomUSART0
+
+// SPI pins.
+const (
+	SPI0_SCK_PIN = PA05 // SCK: SERCOM0/PAD[1]
+	SPI0_SDO_PIN = PA04 // MOSI: SERCOM0/PAD[0]
+	SPI0_SDI_PIN = NoPin
+	SPI0_CS_PIN  = NoPin
+)
+
+// SPI on the Gemma M0.
+var SPI0 = sercomSPIM0
+
+// SPI pins for DotStar LED (using APA102 software SPI) and Flash.
+const (
+	SPI1_SCK_PIN = PA01 // SCK: SERCOM1/PAD[0]
+	SPI1_SDO_PIN = PA00 // MOSI: SERCOM1/PAD[1]
+	SPI1_SDI_PIN = PA31 // MISO: SERCOM1/PAD[3]
+	SPI1_CS_PIN  = PA30 // CS: SERCOM1/PAD[2]
+)
+
+// I2C pins.
+const (
+	SDA_PIN = PA04 // SDA: SERCOM0/PAD[0]
+	SCL_PIN = PA05 // SCL: SERCOM0/PAD[1]
+)
+
+// I2C on the Gemma M0.
+var (
+	I2C0 = sercomI2CM0
+)
+
+// I2S (not connected, needed for atsamd21).
+const (
+	I2S_SCK_PIN = NoPin
+	I2S_SD_PIN  = NoPin
+	I2S_WS_PIN  = NoPin
+)
+
+// USB CDC identifiers.
+const (
+	usb_STRING_PRODUCT      = "Adafruit Gemma M0"
+	usb_STRING_MANUFACTURER = "Adafruit"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x801E
+)
+
+var (
+	DefaultUART = UART0
+)

targets/gemma-m0.json

@@ -0,0 +1,10 @@
+{
+    "inherits": ["atsamd21e18a"],
+    "build-tags": ["gemma_m0"],
+    "serial": "usb",
+    "serial-port": ["239a:801e"],
+    "flash-1200-bps-reset": "true",
+    "flash-method": "msd",
+    "msd-volume-name": ["GEMMABOOT"],
+    "msd-firmware-name": "firmware.uf2"
+}