ALSA: usb-audio: add Starr Labs USB MIDI support

Add support for Starr Labs USB MIDI devices such as the Z7S, which are
based on an FTDI serial UART chip.

Based on a patch by Daniel Mack.

Signed-off-by: Kristian Amlie <kristian@amlie.name>
Acked-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index a42e3ef..da89822 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -39,6 +39,17 @@
 	.idProduct = prod, \
 	.bInterfaceClass = USB_CLASS_VENDOR_SPEC
 
+/* FTDI devices */
+{
+	USB_DEVICE(0x0403, 0xb8d8),
+	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
+		/* .vendor_name = "STARR LABS", */
+		/* .product_name = "Starr Labs MIDI USB device", */
+		.ifnum = 0,
+		.type = QUIRK_MIDI_FTDI
+	}
+},
+
 /* Creative/Toshiba Multimedia Center SB-0500 */
 {
 	USB_DEVICE(0x041e, 0x3048),