[PATCH RFC 1/4] snd-usb-audio: Playback and MIDI support for Novation Twitch DJ controller

[Mark Hills <mark@xwax.org>]

The hardware also has a PCM capture device which is not implemented
in this patch.

It may be possible to generalise this to Saffire 6 USB support
and some of the other Focusrite interfaces, but as I don't have
access to these devices we should wait until capture support is
working first.
---
 sound/usb/quirks-table.h | 40 ++++++++++++++++++++++++++++++++++++++++
 sound/usb/quirks.c       | 15 +++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h
index 820580a..1c8db85 100644
--- a/sound/usb/quirks-table.h
+++ b/sound/usb/quirks-table.h
@@ -2677,6 +2677,46 @@ YAMAHA_DEVICE(0x7010, "UB99"),
 	}
 },
 {
+	USB_DEVICE(0x1235, 0x0018),
+	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
+		.vendor_name = "Novation",
+		.product_name = "Twitch",
+		.ifnum = QUIRK_ANY_INTERFACE,
+		.type = QUIRK_COMPOSITE,
+		.data = (const struct snd_usb_audio_quirk[]) {
+			{
+				.ifnum = 0,
+				.type = QUIRK_AUDIO_FIXED_ENDPOINT,
+				.data = & (const struct audioformat) {
+					.formats = SNDRV_PCM_FMTBIT_S24_3LE,
+					.channels = 4,
+					.iface = 0,
+					.altsetting = 1,
+					.altset_idx = 1,
+					.attributes = UAC_EP_CS_ATTR_SAMPLE_RATE,
+					.endpoint = 0x01,
+					.ep_attr = USB_ENDPOINT_XFER_ISOC,
+					.rates = SNDRV_PCM_RATE_44100 |
+						 SNDRV_PCM_RATE_48000,
+					.rate_min = 44100,
+					.rate_max = 48000,
+					.nr_rates = 2,
+					.rate_table = (unsigned int[]) {
+						44100, 48000
+					}
+				}
+			},
+			{
+				.ifnum = 1,
+				.type = QUIRK_MIDI_RAW_BYTES
+			},
+			{
+				.ifnum = -1
+			}
+		}
+	}
+},
+{
 	USB_DEVICE_VENDOR_SPEC(0x1235, 0x4661),
 	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
 		.vendor_name = "Novation",
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 0115289..b0f7140 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -446,6 +446,17 @@ static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
 }
 
 /*
+ * Novation Twitch DJ controller
+ */
+static int snd_usb_twitch_boot_quirk(struct usb_device *dev)
+{
+	/* preemptively set up the device because otherwise the
+	 * raw MIDI endpoints are not active */
+	usb_set_interface(dev, 0, 1);
+	return 0;
+}
+
+/*
  * This call will put the synth in "USB send" mode, i.e it will send MIDI
  * messages through USB (this is disabled at startup). The synth will
  * acknowledge by sending a sysex on endpoint 0x85 and by displaying a USB
@@ -746,6 +757,10 @@ int snd_usb_apply_boot_quirk(struct usb_device *dev,
 		/* Digidesign Mbox 2 */
 		return snd_usb_mbox2_boot_quirk(dev);
 
+	case USB_ID(0x1235, 0x0018):
+		/* Focusrite Novation Twitch */
+		return snd_usb_twitch_boot_quirk(dev);
+
 	case USB_ID(0x133e, 0x0815):
 		/* Access Music VirusTI Desktop */
 		return snd_usb_accessmusic_boot_quirk(dev);
-- 
1.7.12.1