ALSA: usb-audio: add support for E-Mu Tracker Pre

Add support for the E-Mu "Tracker Pre" USB sound card, following
the example of the (very similar) E-Mu 0202 and E-Mu 0404 USB.

As with the 0202 and 0404 USB, functionality is very limited:
just a couple of sample rates, no volume/mute control, etc.

Signed-off-by: Eran Tromer <eran@tromer.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/usb/usbaudio.c

@@ -484,7 +484,7 @@ static int retire_playback_sync_urb_hs(struct snd_usb_substream *subs,
 }
 
 /*
- * process after E-Mu 0202/0404 high speed playback sync complete
+ * process after E-Mu 0202/0404/Tracker Pre high speed playback sync complete
  *
  * These devices return the number of samples per packet instead of the number
  * of samples per microframe.
@@ -2264,6 +2264,7 @@ static void init_substream(struct snd_usb_stream *as, int stream, struct audiofo
 		switch (as->chip->usb_id) {
 		case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
 		case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
+		case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
 			subs->ops.retire_sync = retire_playback_sync_urb_hs_emu;
 			break;
 		}

sound/usb/usbquirks.h

@@ -62,6 +62,13 @@
 	.idProduct = 0x3f04,
 	.bInterfaceClass = USB_CLASS_AUDIO,
 },
+{
+	/* E-Mu Tracker Pre */
+	.match_flags = USB_DEVICE_ID_MATCH_DEVICE,
+	.idVendor = 0x041e,
+	.idProduct = 0x3f0a,
+	.bInterfaceClass = USB_CLASS_AUDIO,
+},
 
 /*
  * Logitech QuickCam: bDeviceClass is vendor-specific, so generic interface