w5500: initial version the driver (#788)

Thank you, @nrwiersma for working on this and @soypat for review. Now merging.

w5500/w5500.go

@@ -0,0 +1,248 @@
+// Package w5500 implements a driver for the W5500 Ethernet controller.
+//
+// The driver supports basic network functionality including TCP and UDP sockets.
+// It currently does not use the IRQ or RST pins.
+//
+// Datasheet: https://docs.wiznet.io/img/products/w5500/W5500_ds_v110e.pdf
+// Product Page: https://wiznet.io/products/ethernet-chips/w5500
+package w5500
+
+import (
+	"errors"
+	"net"
+	"net/netip"
+	"sync"
+
+	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/pin"
+	"tinygo.org/x/drivers/netdev"
+)
+
+var _ netdev.Netdever = &Device{}
+
+// Resolver is a function that resolves a hostname to an IP address.
+type Resolver func(host string) (netip.Addr, error)
+
+// Device is a driver for the W5500 Ethernet controller.
+type Device struct {
+	maxSockets  int
+	maxSockSize int
+
+	mu  sync.Mutex
+	bus drivers.SPI
+	cs  pin.OutputFunc
+	dns Resolver
+
+	sockets []*socket
+	laddr   netip.Addr
+
+	cmdBuf [3]byte
+}
+
+// New returns a new w5500 driver.
+func New(bus drivers.SPI, csPin pin.Output) *Device {
+	return &Device{
+		bus: bus,
+		cs:  csPin.Set,
+	}
+}
+
+// Config is the configuration for the device.
+//
+// The SPI bus must be fully configured.
+type Config struct {
+	DNS Resolver
+
+	MAC        net.HardwareAddr
+	IP         netip.Addr
+	SubnetMask netip.Addr
+	Gateway    netip.Addr
+
+	// Optional, default is 8.
+	MaxSockets int
+}
+
+// Configure sets up the device.
+//
+// MAC address must be provided. The other fields are optional.
+func (d *Device) Configure(cfg Config) error {
+	d.cs(true)
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.dns = cfg.DNS
+
+	d.reset()
+
+	if err := d.setupSockets(cfg.MaxSockets); err != nil {
+		return errors.New("could not setup sockets: " + err.Error())
+	}
+
+	// Set the MAC address and IP configuration.
+	d.write(regMAC, 0, cfg.MAC)
+	d.write(regIPAddr, 0, cfg.IP.AsSlice())
+	d.write(regSubnetMask, 0, cfg.SubnetMask.AsSlice())
+	d.write(regGatewayAddr, 0, cfg.Gateway.AsSlice())
+	d.laddr = cfg.IP
+
+	return nil
+}
+
+func (d *Device) setupSockets(maxSockets int) error {
+	if maxSockets == 0 {
+		maxSockets = 8 // Default to 8 sockets if not specified.
+	}
+	switch maxSockets {
+	case 1, 2, 4, 8:
+		// Valid socket counts.
+	default:
+		return errors.New("invalid number of sockets, must be one of 1, 2, 4, or 8")
+	}
+
+	socks := make([]*socket, maxSockets)
+	for i := range socks {
+		socks[i] = &socket{
+			sockn: uint8(i),
+		}
+	}
+
+	d.maxSockets = maxSockets
+	d.maxSockSize = 16 * 1024 / maxSockets
+	d.sockets = socks
+
+	// Set the RX and TX buffer sizes for each socket.
+	for i := 0; i < 8; i++ {
+		size := byte(d.maxSockSize >> 10)
+		if i >= maxSockets {
+			size = 0
+		}
+
+		d.writeByte(sockRXBUFSize, sockAddr(uint8(i)), size)
+		d.writeByte(sockTXBUFSize, sockAddr(uint8(i)), size)
+	}
+
+	mask := byte(0b11111111)
+	switch maxSockets {
+	case 1:
+		mask = 0b00000001
+	case 2:
+		mask = 0b00000011
+	case 4:
+		mask = 0b00001111
+	}
+	d.writeByte(regSockIntMask, 0, mask)
+	d.writeByte(regIntMask, 0, 0)
+	return nil
+}
+
+// Reset performs a soft reset.
+func (d *Device) Reset() {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.reset()
+}
+
+func (d *Device) reset() {
+	// RST is bit 7 of regMode.
+	d.writeByte(regMode, 0, 0x80)
+}
+
+// GetHardwareAddr returns the hardware address of the device.
+func (d *Device) GetHardwareAddr() (net.HardwareAddr, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	mac := make([]byte, 6)
+	d.read(regMAC, 0, mac)
+	return mac, nil
+}
+
+// Addr returns the IP address of the device.
+func (d *Device) Addr() (netip.Addr, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	var ip [4]byte
+	d.read(regIPAddr, 0, ip[:])
+	return netip.AddrFrom4(ip), nil
+}
+
+// SetAddr sets the IP address of the device.
+//
+// The IP address must be a valid IPv4 address.
+func (d *Device) SetAddr(ip netip.Addr) error {
+	if err := d.setAddress(regIPAddr, ip); err != nil {
+		return errors.New("could not set IP address: " + err.Error())
+	}
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.laddr = ip
+	return nil
+}
+
+// SetSubnetMask sets the subnet mask of the device.
+//
+// The subnet mask must be a valid IPv4 address.
+// It is not checked if the subnet mask is valid for the device's IP address.
+func (d *Device) SetSubnetMask(mask netip.Addr) error {
+	return d.setAddress(regSubnetMask, mask)
+}
+
+// SetGateway sets the gateway address of the device.
+//
+// The gateway must be a valid IPv4 address.
+// It is not checked if the gateway is in the same subnet as the device.
+func (d *Device) SetGateway(gateway netip.Addr) error {
+	return d.setAddress(regGatewayAddr, gateway)
+}
+
+func (d *Device) setAddress(addr uint16, ip netip.Addr) error {
+	if !ip.IsValid() || !ip.Is4() {
+		return errors.New("invalid IP address: " + ip.String())
+	}
+
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.write(addr, 0, ip.AsSlice())
+	return nil
+}
+
+// LinkStatus is the link status of the device.
+type LinkStatus = uint8
+
+// LinkStatus values.
+const (
+	LinkStatusDown LinkStatus = iota
+	LinkStatusUp
+)
+
+// LinkStatus returns the current link status of the device.
+func (d *Device) LinkStatus() LinkStatus {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	return d.readByte(regPHYCfg, 0) & 0b00000001
+}
+
+// LinkInfo returns the current link information of the device.
+func (d *Device) LinkInfo() string {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	linkInfo := d.readByte(regPHYCfg, 0) & 0b00000110
+
+	speed := "10Mbps"
+	if linkInfo&0b00000010 != 0 {
+		speed = "100Mbps"
+	}
+	duplex := "Half Duplex"
+	if linkInfo&0b00000100 != 0 {
+		duplex = "Full Duplex"
+	}
+	return speed + " " + duplex
+}