tested for libusb-1.0.19 on windows (MinGw)

usb/usb.go

@@ -15,7 +15,10 @@
 // Package usb provides a wrapper around libusb-1.0.
 package usb
 
-// #cgo LDFLAGS: -lusb-1.0
+// #cgo windows CFLAGS: -ID:/lib/libusb-1.0.19/include
+// #cgo windows amd64 LDFLAGS: D:/lib/libusb-1.0.19/MinGW64/static/libusb-1.0.a
+// #cgo windows 386 LDFLAGS: D:/lib/libusb-1.0.19/MinGW32/static/libusb-1.0.a
+// #cgo !windows LDFLAGS: -lusb-1.0
 // #include <libusb-1.0/libusb.h>
 import "C"
 
@@ -106,6 +109,22 @@ func (c *Context) ListDevices(each func(desc *Descriptor) bool) ([]*Device, erro
 	return ret, reterr
 }
 
+// OpenDeviceWithVidPid opens Device from specific VendorId and ProductId.
+// If there are any errors, it'll returns at second value.
+func (c *Context) OpenDeviceWithVidPid(vid, pid int) (*Device, error) {
+	handle := C.libusb_open_device_with_vid_pid(c.ctx, (C.uint16_t)(vid), (C.uint16_t)(pid))
+	dev := C.libusb_get_device(handle)
+	desc, err := newDescriptor(dev)
+
+	// return an error from nil-handle and nil-device
+	if err != nil {
+		return nil, err
+	}
+
+	device := newDevice(handle, desc)
+	return device, nil
+}
+
 func (c *Context) Close() error {
 	close(c.done)
 	if c.ctx != nil {

usb/usb_test.go

@@ -81,13 +81,53 @@ func TestEnum(t *testing.T) {
 	}
 }
 
+func TestOpenDeviceWithVidPid(t *testing.T) {
+	c := NewContext()
+	defer c.Close()
+	c.Debug(0)
+
+	// Accept for all device
+	devs, err := c.ListDevices(func(desc *Descriptor) bool {
+		return true
+	})
+	defer func() {
+		for _, d := range devs {
+			d.Close()
+		}
+	}()
+
+	if err != nil {
+		t.Fatalf("list: %s", err)
+	}
+
+	for i := range devs {
+		vid := devs[i].Vendor
+		pid := devs[i].Product
+		device, err := c.OpenDeviceWithVidPid((int)(vid), (int)(pid))
+
+		// if the context failed to open device
+		if err != nil {
+			t.Fail()
+		}
+
+		// if opened device was not valid
+		if device.Descriptor.Bus != devs[i].Bus ||
+			device.Descriptor.Address != devs[i].Address ||
+			device.Vendor != devs[i].Vendor ||
+			device.Product != devs[i].Product {
+			t.Fail()
+		}
+
+	}
+}
+
 func TestMultipleContexts(t *testing.T) {
 	var buf bytes.Buffer
 	log.SetOutput(&buf)
 	for i := 0; i < 2; i++ {
 		ctx := NewContext()
 		_, err := ctx.ListDevices(func(desc *Descriptor) bool {
-			return false
+			return true
 		})
 		if err != nil {
 			t.Fatal(err)