Use Protocol type for USB interface protocol.

usb/config.go

@@ -86,7 +86,7 @@ type InterfaceSetup struct {
 	// IfClass is the USB-IF subclass code, as defined by the USB spec.
 	IfSubClass Class
 	// IfProtocol is USB protocol code, as defined by the USB spe.c
-	IfProtocol uint8
+	IfProtocol Protocol
 	// Endpoints has the list of endpoints available on this interface with
 	// this alternate setting.
 	Endpoints []EndpointInfo

usb/constants.go

@@ -19,6 +19,7 @@ package usb
 import "C"
 import "strconv"
 
+// Class represents a USB-IF class or subclass code.
 type Class uint8
 
 const (
@@ -58,6 +59,14 @@ func (c Class) String() string {
 	return strconv.Itoa(int(c))
 }
 
+// Protocol is the interface class protocol, qualified by the values
+// of interface class and subclass.
+type Protocol uint8
+
+func (p Protocol) String() string {
+	return strconv.Itoa(int(p))
+}
+
 type DescriptorType uint8
 
 const (

usb/descriptor.go

@@ -29,9 +29,9 @@ type Descriptor struct {
 	Product ID // The Product identifier
 
 	// Protocol information
-	Class    Class // The class of this device
-	SubClass Class // The sub-class (within the class) of this device
-	Protocol uint8 // The protocol (within the sub-class) of this device
+	Class    Class    // The class of this device
+	SubClass Class    // The sub-class (within the class) of this device
+	Protocol Protocol // The protocol (within the sub-class) of this device
 
 	// Configuration information
 	Configs []ConfigInfo

usb/libusb.go

@@ -245,7 +245,7 @@ func (libusbImpl) getDeviceDesc(d *libusbDevice) (*Descriptor, error) {
 					Alternate:  uint8(alt.bAlternateSetting),
 					IfClass:    Class(alt.bInterfaceClass),
 					IfSubClass: Class(alt.bInterfaceSubClass),
-					IfProtocol: uint8(alt.bInterfaceProtocol),
+					IfProtocol: Protocol(alt.bInterfaceProtocol),
 				}
 				var ends []C.struct_libusb_endpoint_descriptor
 				*(*reflect.SliceHeader)(unsafe.Pointer(&ends)) = reflect.SliceHeader{
@@ -278,7 +278,7 @@ func (libusbImpl) getDeviceDesc(d *libusbDevice) (*Descriptor, error) {
 		Product:  ID(desc.idProduct),
 		Class:    Class(desc.bDeviceClass),
 		SubClass: Class(desc.bDeviceSubClass),
-		Protocol: uint8(desc.bDeviceProtocol),
+		Protocol: Protocol(desc.bDeviceProtocol),
 		Configs:  cfgs,
 	}, nil
 }

usbid/describe.go

@@ -58,7 +58,7 @@ func Describe(val interface{}) string {
 func Classify(val interface{}) string {
 	var (
 		class, sub usb.Class
-		proto      uint8
+		proto      usb.Protocol
 	)
 	switch val := val.(type) {
 	case *usb.Descriptor:

usbid/parse.go

@@ -63,7 +63,7 @@ func (c Class) String() string {
 // A SubClass contains the name of the subclass and any associated protocols.
 type SubClass struct {
 	Name     string
-	Protocol map[uint8]string
+	Protocol map[usb.Protocol]string
 }
 
 // String returns the name of the SubClass.
@@ -186,9 +186,9 @@ func ParseIDs(r io.Reader) (map[usb.ID]*Vendor, map[usb.Class]*Class, error) {
 			}
 
 			if subclass.Protocol == nil {
-				subclass.Protocol = make(map[uint8]string)
+				subclass.Protocol = make(map[usb.Protocol]string)
 			}
-			subclass.Protocol[uint8(id)] = name
+			subclass.Protocol[usb.Protocol(id)] = name
 
 		default:
 			return fmt.Errorf("too many levels of nesting for class")

usbid/testdata_test.go

@@ -64,7 +64,7 @@ var (
 				0x01: {Name: "Direct Line"},
 				0x02: {
 					Name: "Abstract (modem)",
-					Protocol: map[uint8]string{
+					Protocol: map[usb.Protocol]string{
 						0x00: "None",
 						0x01: "AT-commands (v.25ter)",
 						0x02: "AT-commands (PCCA101)",