hci: allow for both ninafw and pure hci uart adapter implementations

Signed-off-by: deadprogram <[email protected]>

adapter_hci.go

@@ -0,0 +1,176 @@
+//go:build hci || ninafw
+
+package bluetooth
+
+import (
+	"machine"
+	"runtime"
+
+	"time"
+)
+
+// hciAdapter represents the implementation for the UART connection to the HCI controller.
+type hciAdapter struct {
+	uart *machine.UART
+	hci  *hci
+	att  *att
+
+	isDefault bool
+	scanning  bool
+
+	connectHandler func(device Device, connected bool)
+
+	connectedDevices     []Device
+	notificationsStarted bool
+}
+
+func (a *hciAdapter) enable() error {
+	a.hci.start()
+
+	if err := a.hci.reset(); err != nil {
+		return err
+	}
+
+	time.Sleep(150 * time.Millisecond)
+
+	if err := a.hci.setEventMask(0x3FFFFFFFFFFFFFFF); err != nil {
+		return err
+	}
+
+	return a.hci.setLeEventMask(0x00000000000003FF)
+}
+
+func (a *hciAdapter) Address() (MACAddress, error) {
+	if err := a.hci.readBdAddr(); err != nil {
+		return MACAddress{}, err
+	}
+
+	return MACAddress{MAC: makeAddress(a.hci.address)}, nil
+}
+
+func newBLEStack(uart *machine.UART) (*hci, *att) {
+	h := newHCI(uart)
+	a := newATT(h)
+	h.att = a
+
+	l := newL2CAP(h)
+	h.l2cap = l
+
+	return h, a
+}
+
+// Convert a NINA MAC address into a Go MAC address.
+func makeAddress(mac [6]uint8) MAC {
+	return MAC{
+		uint8(mac[0]),
+		uint8(mac[1]),
+		uint8(mac[2]),
+		uint8(mac[3]),
+		uint8(mac[4]),
+		uint8(mac[5]),
+	}
+}
+
+// Convert a Go MAC address into a NINA MAC Address.
+func makeNINAAddress(mac MAC) [6]uint8 {
+	return [6]uint8{
+		uint8(mac[0]),
+		uint8(mac[1]),
+		uint8(mac[2]),
+		uint8(mac[3]),
+		uint8(mac[4]),
+		uint8(mac[5]),
+	}
+}
+
+func (a *hciAdapter) startNotifications() {
+	if a.notificationsStarted {
+		return
+	}
+
+	if debug {
+		println("starting notifications...")
+	}
+
+	a.notificationsStarted = true
+
+	// go routine to poll for HCI events for ATT notifications
+	go func() {
+		for {
+			if err := a.att.poll(); err != nil {
+				// TODO: handle error
+				if debug {
+					println("error polling for notifications:", err.Error())
+				}
+			}
+
+			time.Sleep(5 * time.Millisecond)
+		}
+	}()
+
+	// go routine to handle characteristic notifications
+	go func() {
+		for {
+			select {
+			case not := <-a.att.notifications:
+				if debug {
+					println("notification received", not.connectionHandle, not.handle, not.data)
+				}
+
+				d := a.findConnection(not.connectionHandle)
+				if d.deviceInternal == nil {
+					if debug {
+						println("no device found for handle", not.connectionHandle)
+					}
+					continue
+				}
+
+				n := d.findNotificationRegistration(not.handle)
+				if n == nil {
+					if debug {
+						println("no notification registered for handle", not.handle)
+					}
+					continue
+				}
+
+				if n.callback != nil {
+					n.callback(not.data)
+				}
+
+			default:
+			}
+
+			runtime.Gosched()
+		}
+	}()
+}
+
+func (a *hciAdapter) addConnection(d Device) {
+	a.connectedDevices = append(a.connectedDevices, d)
+}
+
+func (a *hciAdapter) removeConnection(d Device) {
+	for i := range a.connectedDevices {
+		if d.handle == a.connectedDevices[i].handle {
+			a.connectedDevices[i] = a.connectedDevices[len(a.connectedDevices)-1]
+			a.connectedDevices[len(a.connectedDevices)-1] = Device{}
+			a.connectedDevices = a.connectedDevices[:len(a.connectedDevices)-1]
+
+			return
+		}
+	}
+}
+
+func (a *hciAdapter) findConnection(handle uint16) Device {
+	for _, d := range a.connectedDevices {
+		if d.handle == handle {
+			if debug {
+				println("found device", handle, d.Address.String(), "with notifications registered", len(d.notificationRegistrations))
+			}
+
+			return d
+		}
+	}
+
+	return Device{}
+}

adapter_hci_uart.go

@@ -0,0 +1,64 @@
+//go:build hci && hci_uart
+
+package bluetooth
+
+import (
+	"machine"
+)
+
+const maxConnections = 1
+
+// Adapter represents the UART connection to the HCI controller.
+type Adapter struct {
+	hciAdapter
+
+	// used for software flow control
+	cts, rts machine.Pin
+}
+
+// DefaultAdapter is the default adapter on the current system.
+//
+// Make sure to call Enable() before using it to initialize the adapter.
+var DefaultAdapter = &Adapter{
+	isDefault: true,
+	connectHandler: func(device Device, connected bool) {
+		return
+	},
+	connectedDevices: make([]Device, 0, maxConnections),
+}
+
+// SetUART sets the UART to use for the HCI connection.
+// It must be called before calling Enable().
+// Note that the UART must be configured with hardware flow control, or
+// SetSoftwareFlowControl() must be called.
+func (a *Adapter) SetUART(uart *machine.UART) error {
+	a.uart = uart
+
+	return nil
+}
+
+// SetSoftwareFlowControl sets the pins to use for software flow control,
+// if hardware flow control is not available.
+func (a *Adapter) SetSoftwareFlowControl(cts, rts machine.Pin) error {
+	a.cts = cts
+	a.rts = rts
+
+	return nil
+}
+
+// Enable configures the BLE stack. It must be called before any
+// Bluetooth-related calls (unless otherwise indicated).
+func (a *Adapter) Enable() error {
+	a.hci, a.att = newBLEStack(a.uart)
+
+	if a.cts != 0 && a.rts != 0 {
+		a.hci.softRTS = a.rts
+		a.hci.softRTS.Configure(machine.PinConfig{Mode: machine.PinOutput})
+		a.hci.softRTS.High()
+
+		a.hci.softCTS = a.cts
+		a.cts.Configure(machine.PinConfig{Mode: machine.PinInput})
+	}
+
+	a.enable()
+}