diff --git a/lsusb/main.go b/lsusb/main.go
index c7c3b28..dc30939 100644
--- a/lsusb/main.go
+++ b/lsusb/main.go
@@ -38,7 +38,7 @@ func main() {
 			fmt.Printf("  %s:\n", cfg)
 			for _, alt := range cfg.Interfaces {
 				fmt.Printf("    --------------\n")
-				for _, iface := range alt {
+				for _, iface := range alt.Setups {
 					fmt.Printf("    %s\n", iface)
 					fmt.Printf("      %s\n", usbid.Classify(iface))
 					for _, end := range iface.Endpoints {
diff --git a/usb/config.go b/usb/config.go
index 80d5eb3..e0e37d4 100644
--- a/usb/config.go
+++ b/usb/config.go
@@ -11,7 +11,6 @@ import (
 )
 
 type EndpointInfo struct {
-	Type          DescriptorType
 	Address       uint8
 	Attributes    uint8
 	MaxPacketSize uint16
@@ -38,7 +37,15 @@ func (e EndpointInfo) String() string {
 }
 
 type InterfaceInfo struct {
-	Type       DescriptorType
+	Number uint8
+	Setups []InterfaceSetup
+}
+
+func (i InterfaceInfo) String() string {
+	return fmt.Sprintf("Interface %02x (%d setups)", i.Number, len(i.Setups))
+}
+
+type InterfaceSetup struct {
 	Number     uint8
 	Alternate  uint8
 	IfClass    uint8
@@ -47,16 +54,15 @@ type InterfaceInfo struct {
 	Endpoints  []EndpointInfo
 }
 
-func (i InterfaceInfo) String() string {
-	return fmt.Sprintf("Interface %02x (config %02x)", i.Number, i.Alternate)
+func (a InterfaceSetup) String() string {
+	return fmt.Sprintf("Interface %02x Setup %02x", a.Number, a.Alternate)
 }
 
 type ConfigInfo struct {
-	Type       DescriptorType
 	Config     uint8
 	Attributes uint8
 	MaxPower   uint8
-	Interfaces [][]InterfaceInfo
+	Interfaces []InterfaceInfo
 }
 
 func (c ConfigInfo) String() string {
@@ -65,7 +71,6 @@ func (c ConfigInfo) String() string {
 
 func newConfig(cfg *C.struct_libusb_config_descriptor) ConfigInfo {
 	c := ConfigInfo{
-		Type:       DescriptorType(cfg.bDescriptorType),
 		Config:     uint8(cfg.bConfigurationValue),
 		Attributes: uint8(cfg.bmAttributes),
 		MaxPower:   uint8(cfg.MaxPower),
@@ -77,18 +82,21 @@ func newConfig(cfg *C.struct_libusb_config_descriptor) ConfigInfo {
 		Len:  int(cfg.bNumInterfaces),
 		Cap:  int(cfg.bNumInterfaces),
 	}
-	c.Interfaces = make([][]InterfaceInfo, 0, len(ifaces))
+	c.Interfaces = make([]InterfaceInfo, 0, len(ifaces))
 	for _, iface := range ifaces {
+		if iface.num_altsetting == 0 {
+			continue
+		}
+
 		var alts []C.struct_libusb_interface_descriptor
 		*(*reflect.SliceHeader)(unsafe.Pointer(&alts)) = reflect.SliceHeader{
 			Data: uintptr(unsafe.Pointer(iface.altsetting)),
 			Len:  int(iface.num_altsetting),
 			Cap:  int(iface.num_altsetting),
 		}
-		descs := make([]InterfaceInfo, 0, len(alts))
+		descs := make([]InterfaceSetup, 0, len(alts))
 		for _, alt := range alts {
-			i := InterfaceInfo{
-				Type:       DescriptorType(alt.bDescriptorType),
+			i := InterfaceSetup{
 				Number:     uint8(alt.bInterfaceNumber),
 				Alternate:  uint8(alt.bAlternateSetting),
 				IfClass:    uint8(alt.bInterfaceClass),
@@ -104,7 +112,6 @@ func newConfig(cfg *C.struct_libusb_config_descriptor) ConfigInfo {
 			i.Endpoints = make([]EndpointInfo, 0, len(ends))
 			for _, end := range ends {
 				i.Endpoints = append(i.Endpoints, EndpointInfo{
-					Type:          DescriptorType(end.bDescriptorType),
 					Address:       uint8(end.bEndpointAddress),
 					Attributes:    uint8(end.bmAttributes),
 					MaxPacketSize: uint16(end.wMaxPacketSize),
@@ -115,7 +122,10 @@ func newConfig(cfg *C.struct_libusb_config_descriptor) ConfigInfo {
 			}
 			descs = append(descs, i)
 		}
-		c.Interfaces = append(c.Interfaces, descs)
+		c.Interfaces = append(c.Interfaces, InterfaceInfo{
+			Number: descs[0].Number,
+			Setups: descs,
+		})
 	}
 	return c
 }
diff --git a/usb/device.go b/usb/device.go
index b182d38..65259a8 100644
--- a/usb/device.go
+++ b/usb/device.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"reflect"
 	"runtime"
+	"sync"
 	"time"
 	"unsafe"
 )
@@ -22,13 +23,20 @@ type Device struct {
 
 	// Timeouts
 	ControlTimeout time.Duration
+
+	// Claimed interfaces
+	lock    *sync.Mutex
+	claimed map[uint8]int
 }
 
 func newDevice(handle *C.libusb_device_handle, desc *Descriptor) *Device {
+	ifaces := 0
 	d := &Device{
 		handle:         handle,
 		Descriptor:     desc,
 		ControlTimeout: DefaultControlTimeout,
+		lock:           new(sync.Mutex),
+		claimed:        make(map[uint8]int, ifaces),
 	}
 
 	// This doesn't seem to actually get called
@@ -86,7 +94,20 @@ func (d *Device) Close() error {
 	if d.handle == nil {
 		return fmt.Errorf("usb: double close on device")
 	}
+	for iface := range d.claimed {
+		C.libusb_release_interface(d.handle, C.int(iface))
+	}
 	C.libusb_close(d.handle)
 	d.handle = nil
 	return nil
 }
+
+type Interface struct {
+}
+
+func (d *Device) OpenInterface(id uint8) (*Interface, error) {
+	if errno := C.libusb_claim_interface(d.handle, C.int(id)); errno < 0 {
+		return nil, usbError(errno)
+	}
+	return &Interface{}, nil
+}
diff --git a/usb/usb_test.go b/usb/usb_test.go
index f139b86..aedd0ef 100644
--- a/usb/usb_test.go
+++ b/usb/usb_test.go
@@ -26,7 +26,7 @@ func TestEnum(t *testing.T) {
 			t.Logf("- %s:", cfg)
 			for _, alt := range cfg.Interfaces {
 				t.Logf("  --------------")
-				for _, iface := range alt {
+				for _, iface := range alt.Setups {
 					t.Logf("  - %s", iface)
 					t.Logf("    - %s", usbid.Classify(iface))
 					for _, end := range iface.Endpoints {
diff --git a/usbid/describe.go b/usbid/describe.go
index ed813a3..1bb20e6 100644
--- a/usbid/describe.go
+++ b/usbid/describe.go
@@ -39,13 +39,13 @@ func Describe(val interface{}) string {
 //
 // The given val must be one of the following:
 //   - *usb.Descriptor       "Class (SubClass) Protocol"
-//   - *usb.InterfaceInfo    "IfClass (IfSubClass) IfProtocol"
+//   - *usb.InterfaceSetup   "IfClass (IfSubClass) IfProtocol"
 func Classify(val interface{}) string {
 	var class, sub, proto uint8
 	switch val := val.(type) {
 	case *usb.Descriptor:
 		class, sub, proto = val.Class, val.SubClass, val.Protocol
-	case *usb.InterfaceInfo:
+	case *usb.InterfaceSetup:
 		class, sub, proto = val.IfClass, val.IfSubClass, val.IfProtocol
 	default:
 		return fmt.Sprintf("Unknown (%T)", val)