RMII implementation - LAN8720 ethernet

rp2-pio/examples/rmii/main.go

@@ -0,0 +1,279 @@
+package main
+
+import (
+	"errors"
+	"machine"
+	"strconv"
+	"time"
+	"unsafe"
+
+	pio "github.com/tinygo-org/pio/rp2-pio"
+	"github.com/tinygo-org/pio/rp2-pio/piolib"
+)
+
+// Pin configuration matching reference implementation
+// Reference: https://github.com/sandeepmistry/pico-rmii-ethernet/blob/main/examples/httpd/main.c
+const (
+	// TX pins: GPIO 0, 1, 2 (TXD0, TXD1, TX_EN)
+	pinTxBase = machine.GPIO0
+
+	// RX pins: GPIO 3, 4, 5 (RXD0, RXD1, CRS_DV)
+	pinRxBase = machine.GPIO3
+	pinCRSDV  = machine.GPIO5
+
+	// MDIO pins:
+	pinMDC  = machine.GPIO6
+	pinMDIO = machine.GPIO7
+
+	// Reference clock: 		 (50MHz from PHY)
+	pinRefClk = machine.GPIO6
+)
+
+// Network configuration
+var (
+	// MAC address (locally administered)
+	macAddr = [6]byte{0x02, 0x00, 0x00, 0x12, 0x34, 0x56}
+
+	// Static IP configuration (before DHCP)
+	ipAddr  = [4]byte{192, 168, 1, 100}
+	netmask = [4]byte{255, 255, 255, 0}
+	gateway = [4]byte{192, 168, 1, 1}
+)
+
+func main() {
+	cfg := piolib.RMIIConfig{
+		TxRx: piolib.RMIITxRxConfig{
+			TxPin:     pinTxBase,
+			RxPin:     pinRxBase,
+			CRSDVPin:  pinCRSDV,
+			RefClkPin: pinRefClk,
+		},
+		NoZMDIO:      false,
+		MDIO:         pinMDIO,
+		MDC:          pinMDC,
+		RxBufferSize: 2048,
+		TxBufferSize: 2048,
+	}
+	pinMDC.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	pinMDC.Low()
+	// Sleep to allow serial monitor to connect
+	time.Sleep(2 * time.Second)
+	println("=== LAN 8720 RMII ===")
+	device, err := NewLAN8270(pio.PIO0, cfg)
+	if err != nil {
+		panic(err)
+	}
+	// Init Loop:
+	for {
+		err = device.Init()
+		if err == nil {
+			break
+		}
+		println("init failed:", err.Error())
+		println("retrying soon...")
+		time.Sleep(6 * time.Second)
+	}
+	status, err := device.Status()
+	if err != nil {
+		panic("status: " + err.Error())
+	}
+	ctl, _ := device.BasicControl()
+	println("status", formatHex16(uint16(status)), "islinked", status.IsLinked())
+	println("regctl", formatHex16(uint16(ctl)), "isenabled", ctl.IsEnabled())
+	println("PHY ID1:", device.id1, "ID2:", device.id2)
+
+}
+
+// initRMII initializes the RMII interface with PIO and DMA
+// Reference: netif_rmii_ethernet_low_init() from rmii_ethernet.c
+func initRMII(Pio *pio.PIO) (*piolib.RMII, error) {
+	smTx, err := Pio.ClaimStateMachine()
+	if err != nil {
+		return nil, err
+	}
+	smRx, err := Pio.ClaimStateMachine()
+	if err != nil {
+		return nil, err
+	}
+	// Configure RMII
+	cfg := piolib.RMIIConfig{
+		TxRx: piolib.RMIITxRxConfig{
+			TxPin:     pinTxBase,
+			RxPin:     pinRxBase,
+			CRSDVPin:  pinCRSDV,
+			RefClkPin: pinRefClk,
+		},
+		NoZMDIO:      false,
+		MDIO:         pinMDIO,
+		MDC:          pinMDC,
+		RxBufferSize: 2048,
+		TxBufferSize: 2048,
+	}
+	rmii, err := piolib.NewRMII(smTx, smRx, cfg)
+	if err != nil {
+		return nil, err
+	}
+	return rmii, nil
+}
+
+const (
+	regBasicControl = 0x00
+	regBasicStatus  = 0x01
+	regPhyId1       = 0x02
+	regPhyId2       = 0x03
+
+	regAutoNegotiationAdvertisement      = 0x04
+	regAutoNegotiationLinkPartnerAbility = 0x05
+	regAutoNegotiationExpansion          = 0x05
+	regModeControlStatus                 = 0x11
+	regSpecialModes                      = 0x12
+	regSymbolErorCounter                 = 0x1a
+	regSpecialControlStatusIndications   = 0x1b
+	regIRQSourceFlag                     = 0x1d
+	regIRQMask                           = 0x1e
+	regPhySpecialScontrolStatus          = 0x1f
+)
+
+type LAN8720 struct {
+	bus      *piolib.RMII
+	smiaddr  uint8
+	id1, id2 uint16
+}
+
+func NewLAN8270(Pio *pio.PIO, cfg piolib.RMIIConfig) (*LAN8720, error) {
+	smTx, err := Pio.ClaimStateMachine()
+	if err != nil {
+		return nil, err
+	}
+	smRx, err := Pio.ClaimStateMachine()
+	if err != nil {
+		return nil, err
+	}
+	// Configure RMII
+
+	rmii, err := piolib.NewRMII(smTx, smRx, cfg)
+	if err != nil {
+		return nil, err
+	}
+	return &LAN8720{bus: rmii}, nil
+}
+
+type status uint16
+type control uint16
+
+func (c *control) SetEnabled(b bool) {
+	*c &^= 1 << 15
+	if b {
+		*c |= 1 << 15
+	}
+}
+func (c control) IsEnabled() bool {
+	return c&(1<<15) != 0
+}
+
+func (s status) IsLinked() bool {
+	return s&(1<<2) != 0
+}
+
+func (lan *LAN8720) Status() (status, error) {
+	stat, err := lan.readReg(regBasicStatus)
+	return status(stat), err
+}
+
+func (lan *LAN8720) BasicControl() (control, error) {
+	ct, err := lan.readReg(regBasicControl)
+	return control(ct), err
+}
+
+func (lan *LAN8720) Init() error {
+	const maxAddr = 31
+	lan.smiaddr = 255
+	for addr := uint8(0); addr <= maxAddr; addr++ {
+		val, err := lan.bus.MDIORead(addr, regBasicStatus)
+		if err != nil {
+			continue
+		}
+		if val != 0xffff && val != 0x0000 {
+			lan.smiaddr = addr
+			break
+		}
+		time.Sleep(150 * time.Microsecond)
+	}
+	if lan.smiaddr > maxAddr {
+		return errors.New("no PHY found via addr scanning")
+	}
+
+	ctl, err := lan.BasicControl()
+	if err != nil {
+		return errors.New("failed reading basic control: " + err.Error())
+	}
+	ctl.SetEnabled(true)
+	err = lan.writeReg(regBasicControl, uint16(ctl))
+	if err != nil {
+		return err
+	}
+	time.Sleep(50 * time.Millisecond)
+	ctl, err = lan.BasicControl()
+
+	if err != nil {
+		return err
+	} else if ctl.IsEnabled() {
+		println("want ctl bit 16, got:", formatHex16(uint16(ctl)))
+		return errors.New("lan8720 reset failed")
+	}
+	lan.id1, err = lan.readReg(regPhyId1)
+	if err != nil {
+		return err
+	}
+	lan.id2, err = lan.readReg(regPhyId2)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (lan *LAN8720) readReg(reg uint8) (uint16, error) {
+	return lan.bus.MDIORead(lan.smiaddr, reg)
+}
+
+func (lan *LAN8720) writeReg(reg uint8, value uint16) error {
+	return lan.bus.MDIOWrite(lan.smiaddr, reg, value)
+}
+
+// Utility functions for formatting
+
+func formatHex16(val uint16) string {
+	fwd := []byte{'0', 'x'}
+	fwd = appendHex(fwd, byte(val>>8))
+	fwd = appendHex(fwd, byte(val))
+	return unsafe.String(&fwd[0], len(fwd))
+}
+
+func appendHexSep(dst, mac []byte, sep byte) []byte {
+	for i := range mac {
+		dst = appendHex(dst, mac[i])
+		if sep != 0 && i != len(mac)-1 {
+			dst = append(dst, sep)
+		}
+	}
+	return dst
+}
+
+func appendHex(dst []byte, b byte) []byte {
+	const hexChars = "0123456789abcdef"
+	return append(dst, hexChars[b>>4], hexChars[b&0xf])
+}
+
+func appendDec(dst []byte, b byte) []byte {
+	return strconv.AppendInt(dst, int64(b), 10)
+}
+
+func appendDecSep(dst []byte, data []byte, sep byte) []byte {
+	for i := range data {
+		dst = appendDec(dst, data[i])
+		if sep != 0 && i != len(data)-1 {
+			dst = append(dst, sep)
+		}
+	}
+	return dst
+}