apply @gen2thomas suggestions

internal/legacy/pinhal_tinygo.go

@@ -0,0 +1,33 @@
+//go:build baremetal
+
+package legacy
+
+import "machine"
+
+func configurePinOut(p PinOutput) {
+	configurePin(p, machine.PinOutput)
+}
+
+func configurePinInputPulldown(p PinInput) {
+	configurePin(p, pulldown) // some chips do not have pull down, in which case pulldown==machine.PinInput.
+}
+
+func configurePinInput(p PinInput) {
+	configurePin(p, machine.PinInput)
+}
+
+func configurePinInputPullup(p PinInput) {
+	configurePin(p, pullup) // some chips do not have pull up, in which case pullup==machine.PinInput.
+}
+
+func pinIsNoPin(a any) bool {
+	p, ok := a.(machine.Pin)
+	return ok && p == machine.NoPin
+}
+
+func configurePin(p any, mode machine.PinMode) {
+	machinePin, ok := p.(machine.Pin)
+	if ok {
+		machinePin.Configure(machine.PinConfig{Mode: mode})
+	}
+}