w5500: initial version the driver (#788)

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

Author: nrwiersma

examples/w5500/main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"machine"
+	"net"
+	"net/netip"
+	"time"
+
+	"tinygo.org/x/drivers/netdev"
+	"tinygo.org/x/drivers/w5500"
+)
+
+func main() {
+	machine.SPI0.Configure(machine.SPIConfig{
+		Frequency: 33 * machine.MHz,
+	})
+	machine.GPIO17.Configure(machine.PinConfig{Mode: machine.PinOutput})
+
+	eth := w5500.New(machine.SPI0, machine.GPIO17)
+	eth.Configure(w5500.Config{
+		MAC:        net.HardwareAddr{0xee, 0xbe, 0xe9, 0xa9, 0xb6, 0x4f},
+		IP:         netip.AddrFrom4([4]byte{192, 168, 1, 2}),
+		SubnetMask: netip.AddrFrom4([4]byte{255, 255, 255, 0}),
+		Gateway:    netip.AddrFrom4([4]byte{192, 168, 1, 1}),
+	})
+	netdev.UseNetdev(eth)
+
+	for {
+		if eth.LinkStatus() != w5500.LinkStatusUp {
+			println("Waiting for link to be up")
+
+			time.Sleep(1 * time.Second)
+			continue
+		}
+		break
+	}
+}

smoketest.sh

@@ -146,6 +146,7 @@ tinygo build -size short -o ./build/test.uf2 -target=nicenano ./examples/sharpme
 tinygo build -size short -o ./build/test.hex -target=feather-nrf52840 ./examples/max6675/main.go
 tinygo build -size short -o ./build/test.hex -target=pico ./examples/ens160/main.go
 tinygo build -size short -o ./build/test.hex -target=pico ./examples/si5351/main.go
+tinygo build -size short -o ./build/test.hex -target=pico ./examples/w5500/main.go
 # network examples (espat)
 tinygo build -size short -o ./build/test.hex -target=challenger-rp2040 ./examples/net/ntpclient/
 # network examples (wifinina)

w5500/io.go

@@ -0,0 +1,104 @@
+package w5500
+
+import "time"
+
+func (d *Device) irqPoll(sockn uint8, state uint8, deadline time.Time) uint8 {
+	waitTime := 500 * time.Microsecond
+	for {
+		if !deadline.IsZero() && time.Now().After(deadline) {
+			// If a deadline is set and it has passed, return 0.
+			return sockIntUnknown
+		}
+
+		irq := d.readByte(sockInt, sockAddr(sockn)) & 0b00011111
+		if got := irq & state; got != 0 {
+			// Acknowledge the interrupt.
+			d.writeByte(sockInt, sockAddr(sockn), got)
+
+			return got
+		}
+
+		d.mu.Unlock()
+
+		time.Sleep(waitTime)
+
+		// Exponential backoff for polling.
+		waitTime *= 2
+		if waitTime > 10*time.Millisecond {
+			waitTime = 10 * time.Millisecond
+		}
+
+		d.mu.Lock()
+	}
+}
+
+func (d *Device) read(addr uint16, bsb uint8, p []byte) {
+	d.cs(false)
+	if len(p) == 0 {
+		return
+	}
+
+	d.sendReadHeader(addr, bsb)
+	_ = d.bus.Tx(nil, p)
+	d.cs(true)
+}
+
+func (d *Device) readUint16(addr uint16, bsb uint8) uint16 {
+	d.cs(false)
+	d.sendReadHeader(addr, bsb)
+	buf := d.cmdBuf
+	_ = d.bus.Tx(nil, buf[:2])
+	d.cs(true)
+	return uint16(buf[1]) | uint16(buf[0])<<8
+}
+
+func (d *Device) readByte(addr uint16, bsb uint8) byte {
+	d.cs(false)
+	d.sendReadHeader(addr, bsb)
+	r, _ := d.bus.Transfer(byte(0))
+	d.cs(true)
+	return r
+}
+
+func (d *Device) write(addr uint16, bsb uint8, p []byte) {
+	d.cs(false)
+	if len(p) == 0 {
+		return
+	}
+	d.sendWriteHeader(addr, bsb)
+	_ = d.bus.Tx(p, nil)
+	d.cs(true)
+}
+
+func (d *Device) writeUint16(addr uint16, bsb uint8, v uint16) {
+	d.cs(false)
+	d.sendWriteHeader(addr, bsb)
+	buf := d.cmdBuf
+	buf[0] = byte(v >> 8)
+	buf[1] = byte(v & 0xff)
+	_ = d.bus.Tx(buf[:2], nil)
+	d.cs(true)
+}
+
+func (d *Device) writeByte(addr uint16, bsb uint8, b byte) {
+	d.cs(false)
+	d.sendWriteHeader(addr, bsb)
+	_, _ = d.bus.Transfer(b)
+	d.cs(true)
+}
+
+func (d *Device) sendReadHeader(addr uint16, bsb uint8) {
+	buf := d.cmdBuf
+	buf[0] = byte(addr >> 8)
+	buf[1] = byte(addr & 0xff)
+	buf[2] = bsb << 3
+	_ = d.bus.Tx(buf[:], nil)
+}
+
+func (d *Device) sendWriteHeader(addr uint16, bsb uint8) {
+	buf := d.cmdBuf
+	buf[0] = byte(addr >> 8)
+	buf[1] = byte(addr & 0xff)
+	buf[2] = bsb<<3 | 0b100
+	_ = d.bus.Tx(buf[:], nil)
+}