Add Device.Manufacturer(), .Product() and .SerialNumber() (#14)

device.go

@@ -45,6 +45,10 @@ type DeviceDesc struct {
 
 	// Configuration information
 	Configs map[int]ConfigDesc
+
+	iManufacturer int // The Manufacturer descriptor index
+	iProduct      int // The Product descriptor index
+	iSerialNumber int // The SerialNumber descriptor index
 }
 
 // String returns a human-readable version of the device descriptor.
@@ -211,6 +215,24 @@ func (d *Device) GetStringDescriptor(descIndex int) (string, error) {
 	return libusb.getStringDesc(d.handle, descIndex)
 }
 
+// Manufacturer returns the device's manufacturer name.
+// GetStringDescriptor's string conversion rules apply.
+func (d *Device) Manufacturer() (string, error) {
+	return d.GetStringDescriptor(d.Desc.iManufacturer)
+}
+
+// Product returns the device's product name.
+// GetStringDescriptor's string conversion rules apply.
+func (d *Device) Product() (string, error) {
+	return d.GetStringDescriptor(d.Desc.iProduct)
+}
+
+// SerialNumber returns the device's serial number.
+// GetStringDescriptor's string conversion rules apply.
+func (d *Device) SerialNumber() (string, error) {
+	return d.GetStringDescriptor(d.Desc.iSerialNumber)
+}
+
 // SetAutoDetach enables/disables automatic kernel driver detachment.
 // When autodetach is enabled gousb will automatically detach the kernel driver
 // on the interface and reattach it when releasing the interface.