ALSA: usb-audio: add support for Native Instruments MK2 devices

The MK2 generation of Native Instruments' sound cards are in fact
compliant to the USB audio standard of version 2 and other approved USB
standards. However, they come up as vendor-specific device when first
connected but can be told to come up with a new set of descriptors
upon their next enumeration. The interfaces announced by the new
descriptors will be handled by the kernel's class drivers. This is done
by issuing a vendor specific device request and sending the device to
reset.

There are also some vendor-specific USB requests for some mixer elements
that can't be exported in a standard compliant way. The driver now
supports them with quirks handling mechanisms.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 33 insertions, 0 deletions

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index cf8bf088394..e55bd1cac77 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -425,6 +425,34 @@ static int snd_usb_accessmusic_boot_quirk(struct usb_device *dev)
 }
 
 /*
+ * Some sound cards from Native Instruments are in fact compliant to the USB
+ * audio standard of version 2 and other approved USB standards, even though
+ * they come up as vendor-specific device when first connected.
+ *
+ * However, they can be told to come up with a new set of descriptors
+ * upon their next enumeration, and the interfaces announced by the new
+ * descriptors will then be handled by the kernel's class drivers. As the
+ * product ID will also change, no further checks are required.
+ */
+
+static int snd_usb_nativeinstruments_boot_quirk(struct usb_device *dev)
+{
+	int ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+				  0xaf, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+				  cpu_to_le16(1), 0, NULL, 0, 1000);
+
+	if (ret < 0)
+		return ret;
+
+	usb_reset_device(dev);
+
+	/* return -EAGAIN, so the creation of an audio interface for this
+	 * temporary device is aborted. The device will reconnect with a
+	 * new product ID */
+	return -EAGAIN;
+}
+
+/*
  * Setup quirks
  */
 #define AUDIOPHILE_SET			0x01 /* if set, parse device_setup */
@@ -510,6 +538,11 @@ int snd_usb_apply_boot_quirk(struct usb_device *dev,
 	if (id == USB_ID(0x133e, 0x0815))
 		return snd_usb_accessmusic_boot_quirk(dev);
 
+	/* Native Instruments Devices */
+	if (id == USB_ID(0x17cc, 0x1010) || /* Traktor Audio 6 */
+		id == USB_ID(0x17cc, 0x1020)) /* Traktor Audio 10 */
+		return snd_usb_nativeinstruments_boot_quirk(dev);
+
 	return 0;
 }