atsame5x: add support for CAN

Author: sago35

Makefile

@@ -343,8 +343,12 @@ smoketest:
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=atsame54-xpro       examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=atsame54-xpro       examples/can
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-m4-can      examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=feather-m4-can      examples/caninterrupt
+	@$(MD5SUM) test.hex
 	# test pwm
 	$(TINYGO) build -size short -o test.hex -target=itsybitsy-m0        examples/pwm
 	@$(MD5SUM) test.hex

src/examples/can/feather-m4-can.go

@@ -0,0 +1,15 @@
+// +build feather_m4_can
+
+package main
+
+import (
+	"machine"
+)
+
+func init() {
+	// power on the CAN Transceiver
+	// https://learn.adafruit.com/adafruit-feather-m4-can-express/pinouts#can-bus-3078990-8
+	boost_en := machine.BOOST_EN
+	boost_en.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	boost_en.High()
+}

src/examples/can/main.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+	"machine"
+	"time"
+)
+
+func main() {
+	can1 := machine.CAN1
+	can1.Configure(machine.CANConfig{
+		TransferRate:   machine.CANTransferRate500kbps,
+		TransferRateFD: machine.CANTransferRate1000kbps,
+		Rx:             machine.CAN1_RX,
+		Tx:             machine.CAN1_TX,
+		Standby:        machine.CAN1_STANDBY,
+	})
+
+	can0 := machine.CAN0
+	can0.Configure(machine.CANConfig{
+		TransferRate:   machine.CANTransferRate500kbps,
+		TransferRateFD: machine.CANTransferRate1000kbps,
+		Rx:             machine.CAN0_RX,
+		Tx:             machine.CAN0_TX,
+		Standby:        machine.NoPin,
+	})
+
+	rxMsg := machine.CANRxBufferElement{}
+
+	for {
+		can1.Tx(0x123, []byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF}, false, false)
+		can1.Tx(0x789, []byte{0x02, 0x24, 0x46, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF}, true, false)
+		time.Sleep(time.Millisecond * 1000)
+
+		sz0 := can0.RxFifoSize()
+		if sz0 > 0 {
+			fmt.Printf("CAN0 %d\r\n", sz0)
+			for i := 0; i < sz0; i++ {
+				can0.RxRaw(&rxMsg)
+				fmt.Printf("-> %08X %X %#v\r\n", rxMsg.ID, rxMsg.DLC, rxMsg.Data())
+			}
+		}
+
+		sz1 := can1.RxFifoSize()
+		if sz1 > 0 {
+			fmt.Printf("CAN1 %d\r\n", sz1)
+			for i := 0; i < sz1; i++ {
+				can1.RxRaw(&rxMsg)
+				fmt.Printf("-> %08X %X %#v\r\n", rxMsg.ID, rxMsg.DLC, rxMsg.Data())
+			}
+		}
+	}
+}

src/examples/caninterrupt/feather-m4-can.go

@@ -0,0 +1,15 @@
+// +build feather_m4_can
+
+package main
+
+import (
+	"machine"
+)
+
+func init() {
+	// power on the CAN Transceiver
+	// https://learn.adafruit.com/adafruit-feather-m4-can-express/pinouts#can-bus-3078990-8
+	boost_en := machine.BOOST_EN
+	boost_en.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	boost_en.High()
+}

src/examples/caninterrupt/main.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"device/sam"
+	"fmt"
+	"machine"
+	"time"
+)
+
+type canMsg struct {
+	ch   byte
+	id   uint32
+	dlc  byte
+	data []byte
+}
+
+func main() {
+	ch := make(chan canMsg, 10)
+	go func() {
+		for {
+			select {
+			case m := <-ch:
+				fmt.Printf("%d %03X %X ", m.ch, m.id, m.dlc)
+				for _, d := range m.data {
+					fmt.Printf("%02X ", d)
+				}
+				fmt.Printf("\r\n")
+			}
+
+		}
+	}()
+
+	can1 := machine.CAN1
+	can1.Configure(machine.CANConfig{
+		TransferRate:   machine.CANTransferRate500kbps,
+		TransferRateFD: machine.CANTransferRate1000kbps,
+		Rx:             machine.CAN1_RX,
+		Tx:             machine.CAN1_TX,
+		Standby:        machine.CAN1_STANDBY,
+	})
+	// RF0NE : Rx FIFO 0 New Message Interrupt Enable
+	can1.SetInterrupt(sam.CAN_IE_RF0NE, func(*machine.CAN) {
+		rxMsg := machine.CANRxBufferElement{}
+		can1.RxRaw(&rxMsg)
+		m := canMsg{ch: 1, id: rxMsg.ID, dlc: rxMsg.DLC, data: rxMsg.Data()}
+		select {
+		case ch <- m:
+		}
+	})
+
+	can0 := machine.CAN0
+	can0.Configure(machine.CANConfig{
+		TransferRate:   machine.CANTransferRate500kbps,
+		TransferRateFD: machine.CANTransferRate1000kbps,
+		Rx:             machine.CAN0_RX,
+		Tx:             machine.CAN0_TX,
+		Standby:        machine.NoPin,
+	})
+	// RF0NE : Rx FIFO 0 New Message Interrupt Enable
+	can0.SetInterrupt(sam.CAN_IE_RF0NE, func(*machine.CAN) {
+		rxMsg := machine.CANRxBufferElement{}
+		can0.RxRaw(&rxMsg)
+		m := canMsg{ch: 2, id: rxMsg.ID, dlc: rxMsg.DLC, data: rxMsg.Data()}
+		select {
+		case ch <- m:
+		}
+	})
+
+	for {
+		can0.Tx(0x123, []byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF}, false, false)
+		time.Sleep(time.Millisecond * 500)
+		can1.Tx(0x456, []byte{0xAA, 0xBB, 0xCC}, false, false)
+		time.Sleep(time.Millisecond * 1000)
+	}
+}

src/machine/board_atsame54-xpro.go

@@ -328,3 +328,14 @@ var (
 		SERCOM: 6,
 	}
 )
+
+// CAN on the SAM E54 Xplained Pro
+var (
+	CAN0 = CAN{
+		Bus: sam.CAN0,
+	}
+
+	CAN1 = CAN{
+		Bus: sam.CAN1,
+	}
+)

src/machine/board_feather-m4-can.go

@@ -125,18 +125,29 @@ func init() {
 	D7.High()
 }
 
-// I2C on the Feather M4.
+// I2C on the Feather M4 CAN.
 var (
 	I2C0 = &I2C{
 		Bus:    sam.SERCOM2_I2CM,
 		SERCOM: 2,
 	}
 )
 
-// SPI on the Feather M4.
+// SPI on the Feather M4 CAN.
 var (
 	SPI0 = SPI{
 		Bus:    sam.SERCOM1_SPIM,
 		SERCOM: 1,
 	}
 )
+
+// CAN on the Feather M4 CAN.
+var (
+	CAN0 = CAN{
+		Bus: sam.CAN0,
+	}
+
+	CAN1 = CAN{
+		Bus: sam.CAN1,
+	}
+)