First cut

usb/device.go

@@ -0,0 +1,90 @@
+package usb
+
+// #cgo LDFLAGS: -lusb-1.0
+// #include <libusb-1.0/libusb.h>
+import "C"
+
+import (
+	"log"
+	"runtime"
+)
+
+type DeviceInfo struct {
+	dev *C.libusb_device
+}
+
+func newDeviceInfo(dev *C.libusb_device) *DeviceInfo {
+	d := &DeviceInfo{
+		dev: dev,
+	}
+
+	// Reference this device
+	C.libusb_ref_device(dev)
+
+	// I still can't get this to be called
+	runtime.SetFinalizer(d, (*DeviceInfo).Close)
+
+	log.Printf("deviceInfo %p initialized", d.dev)
+	return d
+}
+
+// Get the assigned Bus Number for this USB device.
+func (d *DeviceInfo) BusNumber() byte {
+	return byte(C.libusb_get_bus_number(d.dev))
+}
+
+// Get the assigned Bus Address for this USB device.
+func (d *DeviceInfo) Address() byte {
+	return byte(C.libusb_get_device_address(d.dev))
+}
+
+// Get a descriptor for the device.
+func (d *DeviceInfo) Descriptor() (*Descriptor, error) {
+	return newDescriptor(d.dev)
+}
+
+// Open the given device for I/O.
+func (d *DeviceInfo) Open() (*Device, error) {
+	var handle *C.libusb_device_handle
+	if errno := C.libusb_open(d.dev, &handle); errno != 0 {
+		return nil, usbError(errno)
+	}
+
+	return newDevice(handle), nil
+}
+
+// Close decrements the reference count for the device in the libusb driver
+// code.  It should be called exactly once!
+func (d *DeviceInfo) Close() error {
+	if d.dev != nil {
+		log.Printf("deviceInfo %p closed", d.dev)
+		C.libusb_unref_device(d.dev)
+	}
+	d.dev = nil
+	return nil
+}
+
+type Device struct {
+	handle *C.libusb_device_handle
+}
+
+func newDevice(handle *C.libusb_device_handle) *Device {
+	d := &Device{
+		handle: handle,
+	}
+
+	// :(
+	runtime.SetFinalizer(d, (*Device).Close)
+
+	log.Printf("device %p initialized", d.handle)
+	return d
+}
+
+func (d *Device) Close() error {
+	if d.handle != nil {
+		log.Printf("device %p closed", d.handle)
+		C.libusb_unref_device(d.handle)
+	}
+	d.handle = nil
+	return nil
+}