diff mbox series

[v2,09/37] ALSA: usb-audio: USB MIDI 2.0 UMP support

Message ID 20230523075358.9672-10-tiwai@suse.de
State Accepted
Commit ff49d1df79aef7580fe3ac99d17c3f886655d080
Headers show
Series ALSA: Add MIDI 2.0 support | expand

Commit Message

Takashi Iwai May 23, 2023, 7:53 a.m. UTC
This patch provides a basic support for USB MIDI 2.0.  As of this
patch, the driver creates a UMP device per MIDI I/O endpoints, which
serves as a dumb terminal to read/write UMP streams.

A new Kconfig CONFIG_SND_USB_AUDIO_MIDI_V2 manages whether to enable
or disable the MIDI 2.0 support.  Also, the driver provides a new
module option, midi2_enable, to allow disabling the MIDI 2.0 at
runtime, too.  When MIDI 2.0 support is disabled, the driver tries to
fall back to the already existing MIDI 1.0 device (each MIDI 2.0
device is supposed to provide the MIDI 1.0 interface at the altset
0).

For now, the driver doesn't manage any MIDI-CI or other protocol
setups by itself, but relies on the default protocol given via the
group terminal block descriptors.

The MIDI 1.0 messages on MIDI 2.0 device will be automatically
converted in ALSA sequencer in a later patch.  As of this commit, the
driver accepts merely the rawmidi UMP accesses.

The driver builds up the topology in the following way:
- Create an object for each MIDI endpoint belonging to the USB
  interface
- Find MIDI EP "pairs" that share the same GTB;
  note that MIDI EP is unidirectional, while UMP is (normally)
  bidirectional, so two MIDI EPs can form a single UMP EP
- A UMP endpoint object is created for each I/O pair
- For remaining "solo" MIDI EPs, create unidirectional UMP EPs
- Finally, parse GTBs and fill the protocol bits on each UMP

So the driver may support multiple UMP Endpoints in theory, although
most devices are supposed to have a single UMP EP that can contain up
to 16 groups -- which should be large enough.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/usb/Kconfig    |   11 +
 sound/usb/Makefile   |    1 +
 sound/usb/card.c     |   13 +-
 sound/usb/midi2.c    | 1052 ++++++++++++++++++++++++++++++++++++++++++
 sound/usb/midi2.h    |   33 ++
 sound/usb/quirks.c   |    3 +-
 sound/usb/usbaudio.h |    1 +
 7 files changed, 1109 insertions(+), 5 deletions(-)
 create mode 100644 sound/usb/midi2.c
 create mode 100644 sound/usb/midi2.h
diff mbox series

Patch

diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index 059242f15d75..4a9569a3a39a 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -15,6 +15,7 @@  config SND_USB_AUDIO
 	select SND_HWDEP
 	select SND_RAWMIDI
 	select SND_PCM
+	select SND_UMP if SND_USB_AUDIO_MIDI_V2
 	select BITREVERSE
 	select SND_USB_AUDIO_USE_MEDIA_CONTROLLER if MEDIA_CONTROLLER && (MEDIA_SUPPORT=y || MEDIA_SUPPORT=SND_USB_AUDIO)
 	help
@@ -24,6 +25,16 @@  config SND_USB_AUDIO
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-usb-audio.
 
+config SND_USB_AUDIO_MIDI_V2
+	bool "MIDI 2.0 support by USB Audio driver"
+	depends on SND_USB_AUDIO
+	help
+	  Say Y here to include the support for MIDI 2.0 by USB Audio driver.
+	  When the config is set, the driver tries to probe MIDI 2.0 interface
+	  at first, then falls back to MIDI 1.0 interface as default.
+	  The MIDI 2.0 support can be disabled dynamically via midi2_enable
+	  module option, too.
+
 config SND_USB_AUDIO_USE_MEDIA_CONTROLLER
 	bool
 
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 9ccb21a4ff8a..db5ff76d0e61 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -22,6 +22,7 @@  snd-usb-audio-objs := 	card.o \
 			stream.o \
 			validate.o
 
+snd-usb-audio-$(CONFIG_SND_USB_AUDIO_MIDI_V2) += midi2.o
 snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
 
 snd-usbmidi-lib-objs := midi.o
diff --git a/sound/usb/card.c b/sound/usb/card.c
index bd051e634516..1b2edc0fd2e9 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -44,6 +44,7 @@ 
 #include "usbaudio.h"
 #include "card.h"
 #include "midi.h"
+#include "midi2.h"
 #include "mixer.h"
 #include "proc.h"
 #include "quirks.h"
@@ -178,10 +179,8 @@  static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int int
 	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
 	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
 	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
-		int err = __snd_usbmidi_create(chip->card, iface,
-					       &chip->midi_list, NULL,
-					       chip->usb_id,
-					       &chip->num_rawmidis);
+		int err = snd_usb_midi_v2_create(chip, iface, NULL,
+						 chip->usb_id);
 		if (err < 0) {
 			dev_err(&dev->dev,
 				"%u:%d: cannot create sequencer device\n",
@@ -486,6 +485,7 @@  static void snd_usb_audio_free(struct snd_card *card)
 	struct snd_usb_audio *chip = card->private_data;
 
 	snd_usb_endpoint_free_all(chip);
+	snd_usb_midi_v2_free_all(chip);
 
 	mutex_destroy(&chip->mutex);
 	if (!atomic_read(&chip->shutdown))
@@ -645,6 +645,7 @@  static int snd_usb_audio_create(struct usb_interface *intf,
 	INIT_LIST_HEAD(&chip->iface_ref_list);
 	INIT_LIST_HEAD(&chip->clock_ref_list);
 	INIT_LIST_HEAD(&chip->midi_list);
+	INIT_LIST_HEAD(&chip->midi_v2_list);
 	INIT_LIST_HEAD(&chip->mixer_list);
 
 	if (quirk_flags[idx])
@@ -969,6 +970,7 @@  static void usb_audio_disconnect(struct usb_interface *intf)
 		list_for_each(p, &chip->midi_list) {
 			snd_usbmidi_disconnect(p);
 		}
+		snd_usb_midi_v2_disconnect_all(chip);
 		/*
 		 * Nice to check quirk && quirk->shares_media_device and
 		 * then call the snd_media_device_delete(). Don't have
@@ -1080,6 +1082,7 @@  static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 			snd_usbmidi_suspend(p);
 		list_for_each_entry(mixer, &chip->mixer_list, list)
 			snd_usb_mixer_suspend(mixer);
+		snd_usb_midi_v2_suspend_all(chip);
 	}
 
 	if (!PMSG_IS_AUTO(message) && !chip->system_suspend) {
@@ -1125,6 +1128,8 @@  static int usb_audio_resume(struct usb_interface *intf)
 		snd_usbmidi_resume(p);
 	}
 
+	snd_usb_midi_v2_resume_all(chip);
+
  out:
 	if (chip->num_suspended_intf == chip->system_suspend) {
 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
diff --git a/sound/usb/midi2.c b/sound/usb/midi2.c
new file mode 100644
index 000000000000..7b4cfbaf2ec0
--- /dev/null
+++ b/sound/usb/midi2.c
@@ -0,0 +1,1052 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MIDI 2.0 support
+ */
+
+#include <linux/bitops.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/wait.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/midi.h>
+#include <linux/usb/midi-v2.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/ump.h>
+#include "usbaudio.h"
+#include "midi.h"
+#include "midi2.h"
+#include "helper.h"
+
+static bool midi2_enable = true;
+module_param(midi2_enable, bool, 0444);
+MODULE_PARM_DESC(midi2_enable, "Enable MIDI 2.0 support.");
+
+/* stream direction; just shorter names */
+enum {
+	STR_OUT = SNDRV_RAWMIDI_STREAM_OUTPUT,
+	STR_IN = SNDRV_RAWMIDI_STREAM_INPUT
+};
+
+#define NUM_URBS	8
+
+struct snd_usb_midi2_urb;
+struct snd_usb_midi2_endpoint;
+struct snd_usb_midi2_ump;
+struct snd_usb_midi2_interface;
+
+/* URB context */
+struct snd_usb_midi2_urb {
+	struct urb *urb;
+	struct snd_usb_midi2_endpoint *ep;
+	unsigned int index;		/* array index */
+};
+
+/* A USB MIDI input/output endpoint */
+struct snd_usb_midi2_endpoint {
+	struct usb_device *dev;
+	const struct usb_ms20_endpoint_descriptor *ms_ep; /* reference to EP descriptor */
+	struct snd_usb_midi2_endpoint *pair;	/* bidirectional pair EP */
+	struct snd_usb_midi2_ump *rmidi;	/* assigned UMP EP */
+	int direction;			/* direction (STR_IN/OUT) */
+	unsigned int endpoint;		/* EP number */
+	unsigned int pipe;		/* URB pipe */
+	unsigned int packets;		/* packet buffer size in bytes */
+	unsigned int interval;		/* interval for INT EP */
+	wait_queue_head_t wait;		/* URB waiter */
+	spinlock_t lock;		/* URB locking */
+	struct snd_rawmidi_substream *substream; /* NULL when closed */
+	unsigned int num_urbs;		/* number of allocated URBs */
+	unsigned long urb_free;		/* bitmap for free URBs */
+	unsigned long urb_free_mask;	/* bitmask for free URBs */
+	atomic_t running;		/* running status */
+	atomic_t suspended;		/* saved running status for suspend */
+	bool disconnected;		/* shadow of umidi->disconnected */
+	struct list_head list;		/* list to umidi->ep_list */
+	struct snd_usb_midi2_urb urbs[NUM_URBS];
+};
+
+/* A UMP endpoint - one or two USB MIDI endpoints are assigned */
+struct snd_usb_midi2_ump {
+	struct usb_device *dev;
+	struct snd_usb_midi2_interface *umidi;	/* reference to MIDI iface */
+	struct snd_ump_endpoint *ump;		/* assigned UMP EP object */
+	struct snd_usb_midi2_endpoint *eps[2];	/* USB MIDI endpoints */
+	int index;				/* rawmidi device index */
+	unsigned char usb_block_id;		/* USB GTB id used for finding a pair */
+	struct list_head list;		/* list to umidi->rawmidi_list */
+};
+
+/* top-level instance per USB MIDI interface */
+struct snd_usb_midi2_interface {
+	struct snd_usb_audio *chip;	/* assigned USB-audio card */
+	struct usb_interface *iface;	/* assigned USB interface */
+	struct usb_host_interface *hostif;
+	const char *blk_descs;		/* group terminal block descriptors */
+	unsigned int blk_desc_size;	/* size of GTB descriptors */
+	bool disconnected;
+	struct list_head ep_list;	/* list of endpoints */
+	struct list_head rawmidi_list;	/* list of UMP rawmidis */
+	struct list_head list;		/* list to chip->midi_v2_list */
+};
+
+/* submit URBs as much as possible; used for both input and output */
+static void do_submit_urbs_locked(struct snd_usb_midi2_endpoint *ep,
+				  int (*prepare)(struct snd_usb_midi2_endpoint *,
+						 struct urb *))
+{
+	struct snd_usb_midi2_urb *ctx;
+	int index, err = 0;
+
+	if (ep->disconnected)
+		return;
+
+	while (ep->urb_free) {
+		index = find_first_bit(&ep->urb_free, ep->num_urbs);
+		if (index >= ep->num_urbs)
+			return;
+		ctx = &ep->urbs[index];
+		err = prepare(ep, ctx->urb);
+		if (err < 0)
+			return;
+		if (!ctx->urb->transfer_buffer_length)
+			return;
+		ctx->urb->dev = ep->dev;
+		err = usb_submit_urb(ctx->urb, GFP_ATOMIC);
+		if (err < 0) {
+			dev_dbg(&ep->dev->dev,
+				"usb_submit_urb error %d\n", err);
+			return;
+		}
+		clear_bit(index, &ep->urb_free);
+	}
+}
+
+/* prepare for output submission: copy from rawmidi buffer to urb packet */
+static int prepare_output_urb(struct snd_usb_midi2_endpoint *ep,
+			      struct urb *urb)
+{
+	int count;
+
+	if (ep->substream)
+		count = snd_rawmidi_transmit(ep->substream,
+					     urb->transfer_buffer,
+					     ep->packets);
+	else
+		count = -ENODEV;
+	if (count < 0) {
+		dev_dbg(&ep->dev->dev, "rawmidi transmit error %d\n", count);
+		return count;
+	}
+	cpu_to_le32_array((u32 *)urb->transfer_buffer, count >> 2);
+	urb->transfer_buffer_length = count;
+	return 0;
+}
+
+static void submit_output_urbs_locked(struct snd_usb_midi2_endpoint *ep)
+{
+	do_submit_urbs_locked(ep, prepare_output_urb);
+}
+
+/* URB completion for output; re-filling and re-submit */
+static void output_urb_complete(struct urb *urb)
+{
+	struct snd_usb_midi2_urb *ctx = urb->context;
+	struct snd_usb_midi2_endpoint *ep = ctx->ep;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ep->lock, flags);
+	set_bit(ctx->index, &ep->urb_free);
+	if (urb->status >= 0 && atomic_read(&ep->running))
+		submit_output_urbs_locked(ep);
+	if (ep->urb_free == ep->urb_free_mask)
+		wake_up(&ep->wait);
+	spin_unlock_irqrestore(&ep->lock, flags);
+}
+
+/* prepare for input submission: just set the buffer length */
+static int prepare_input_urb(struct snd_usb_midi2_endpoint *ep,
+			     struct urb *urb)
+{
+	urb->transfer_buffer_length = ep->packets;
+	return 0;
+}
+
+static void submit_input_urbs_locked(struct snd_usb_midi2_endpoint *ep)
+{
+	do_submit_urbs_locked(ep, prepare_input_urb);
+}
+
+/* URB completion for input; copy into rawmidi buffer and resubmit */
+static void input_urb_complete(struct urb *urb)
+{
+	struct snd_usb_midi2_urb *ctx = urb->context;
+	struct snd_usb_midi2_endpoint *ep = ctx->ep;
+	unsigned long flags;
+	int len;
+
+	spin_lock_irqsave(&ep->lock, flags);
+	if (ep->disconnected || urb->status < 0)
+		goto dequeue;
+	len = urb->actual_length;
+	len &= ~3; /* align UMP */
+	if (len > ep->packets)
+		len = ep->packets;
+	if (len > 0 && ep->substream) {
+		le32_to_cpu_array((u32 *)urb->transfer_buffer, len >> 2);
+		snd_rawmidi_receive(ep->substream, urb->transfer_buffer, len);
+	}
+ dequeue:
+	set_bit(ctx->index, &ep->urb_free);
+	submit_input_urbs_locked(ep);
+	if (ep->urb_free == ep->urb_free_mask)
+		wake_up(&ep->wait);
+	spin_unlock_irqrestore(&ep->lock, flags);
+}
+
+/* URB submission helper; for both direction */
+static void submit_io_urbs(struct snd_usb_midi2_endpoint *ep)
+{
+	unsigned long flags;
+
+	if (!ep)
+		return;
+	spin_lock_irqsave(&ep->lock, flags);
+	if (ep->direction == STR_IN)
+		submit_input_urbs_locked(ep);
+	else
+		submit_output_urbs_locked(ep);
+	spin_unlock_irqrestore(&ep->lock, flags);
+}
+
+/* kill URBs for close, suspend and disconnect */
+static void kill_midi_urbs(struct snd_usb_midi2_endpoint *ep, bool suspending)
+{
+	int i;
+
+	if (!ep)
+		return;
+	if (suspending)
+		ep->suspended = ep->running;
+	atomic_set(&ep->running, 0);
+	for (i = 0; i < ep->num_urbs; i++) {
+		if (!ep->urbs[i].urb)
+			break;
+		usb_kill_urb(ep->urbs[i].urb);
+	}
+}
+
+/* wait until all URBs get freed */
+static void drain_urb_queue(struct snd_usb_midi2_endpoint *ep)
+{
+	if (!ep)
+		return;
+	spin_lock_irq(&ep->lock);
+	atomic_set(&ep->running, 0);
+	wait_event_lock_irq_timeout(ep->wait,
+				    ep->disconnected ||
+				    ep->urb_free == ep->urb_free_mask,
+				    ep->lock, msecs_to_jiffies(500));
+	spin_unlock_irq(&ep->lock);
+}
+
+/* release URBs for an EP */
+static void free_midi_urbs(struct snd_usb_midi2_endpoint *ep)
+{
+	struct snd_usb_midi2_urb *ctx;
+	int i;
+
+	if (!ep)
+		return;
+	for (i = 0; i < ep->num_urbs; ++i) {
+		ctx = &ep->urbs[i];
+		if (!ctx->urb)
+			break;
+		usb_free_coherent(ep->dev, ep->packets,
+				  ctx->urb->transfer_buffer,
+				  ctx->urb->transfer_dma);
+		usb_free_urb(ctx->urb);
+		ctx->urb = NULL;
+	}
+	ep->num_urbs = 0;
+}
+
+/* allocate URBs for an EP */
+static int alloc_midi_urbs(struct snd_usb_midi2_endpoint *ep)
+{
+	struct snd_usb_midi2_urb *ctx;
+	void (*comp)(struct urb *urb);
+	void *buffer;
+	int i, err;
+	int endpoint, len;
+
+	endpoint = ep->endpoint;
+	len = ep->packets;
+	if (ep->direction == STR_IN)
+		comp = input_urb_complete;
+	else
+		comp = output_urb_complete;
+
+	ep->num_urbs = 0;
+	ep->urb_free = ep->urb_free_mask = 0;
+	for (i = 0; i < NUM_URBS; i++) {
+		ctx = &ep->urbs[i];
+		ctx->index = i;
+		ctx->urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!ctx->urb) {
+			dev_err(&ep->dev->dev, "URB alloc failed\n");
+			return -ENOMEM;
+		}
+		ctx->ep = ep;
+		buffer = usb_alloc_coherent(ep->dev, len, GFP_KERNEL,
+					    &ctx->urb->transfer_dma);
+		if (!buffer) {
+			dev_err(&ep->dev->dev,
+				"URB buffer alloc failed (size %d)\n", len);
+			return -ENOMEM;
+		}
+		if (ep->interval)
+			usb_fill_int_urb(ctx->urb, ep->dev, ep->pipe,
+					 buffer, len, comp, ctx, ep->interval);
+		else
+			usb_fill_bulk_urb(ctx->urb, ep->dev, ep->pipe,
+					  buffer, len, comp, ctx);
+		err = usb_urb_ep_type_check(ctx->urb);
+		if (err < 0) {
+			dev_err(&ep->dev->dev, "invalid MIDI EP %x\n",
+				endpoint);
+			return err;
+		}
+		ctx->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		ep->num_urbs++;
+	}
+	ep->urb_free = ep->urb_free_mask = GENMASK(ep->num_urbs - 1, 0);
+	return 0;
+}
+
+static struct snd_usb_midi2_endpoint *
+substream_to_endpoint(struct snd_rawmidi_substream *substream)
+{
+	struct snd_ump_endpoint *ump = rawmidi_to_ump(substream->rmidi);
+	struct snd_usb_midi2_ump *rmidi = ump->private_data;
+
+	return rmidi->eps[substream->stream];
+}
+
+/* rawmidi open callback */
+static int snd_usb_midi_v2_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_usb_midi2_endpoint *ep = substream_to_endpoint(substream);
+	int err = 0;
+
+	if (!ep || !ep->endpoint)
+		return -ENODEV;
+	if (ep->disconnected)
+		return -EIO;
+	if (ep->substream)
+		return -EBUSY;
+	if (ep->direction == STR_OUT) {
+		err = alloc_midi_urbs(ep);
+		if (err)
+			return err;
+	}
+	spin_lock_irq(&ep->lock);
+	ep->substream = substream;
+	spin_unlock_irq(&ep->lock);
+	return 0;
+}
+
+/* rawmidi close callback */
+static int snd_usb_midi_v2_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_usb_midi2_endpoint *ep = substream_to_endpoint(substream);
+
+	spin_lock_irq(&ep->lock);
+	ep->substream = NULL;
+	spin_unlock_irq(&ep->lock);
+	if (ep->direction == STR_OUT) {
+		kill_midi_urbs(ep, false);
+		drain_urb_queue(ep);
+		free_midi_urbs(ep);
+	}
+	return 0;
+}
+
+/* rawmidi trigger callback */
+static void snd_usb_midi_v2_trigger(struct snd_rawmidi_substream *substream,
+				    int up)
+{
+	struct snd_usb_midi2_endpoint *ep = substream_to_endpoint(substream);
+
+	atomic_set(&ep->running, up);
+	if (up && ep->direction == STR_OUT && !ep->disconnected)
+		submit_io_urbs(ep);
+}
+
+/* rawmidi drain callback */
+static void snd_usb_midi_v2_drain(struct snd_rawmidi_substream *substream)
+{
+	struct snd_usb_midi2_endpoint *ep = substream_to_endpoint(substream);
+
+	drain_urb_queue(ep);
+}
+
+/* allocate and start all input streams */
+static int start_input_streams(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_endpoint *ep;
+	int err;
+
+	list_for_each_entry(ep, &umidi->ep_list, list) {
+		if (ep->direction == STR_IN) {
+			err = alloc_midi_urbs(ep);
+			if (err < 0)
+				goto error;
+		}
+	}
+
+	list_for_each_entry(ep, &umidi->ep_list, list) {
+		if (ep->direction == STR_IN)
+			submit_io_urbs(ep);
+	}
+
+	return 0;
+
+ error:
+	list_for_each_entry(ep, &umidi->ep_list, list) {
+		if (ep->direction == STR_IN)
+			free_midi_urbs(ep);
+	}
+
+	return err;
+}
+
+static const struct snd_rawmidi_ops output_ops = {
+	.open = snd_usb_midi_v2_open,
+	.close = snd_usb_midi_v2_close,
+	.trigger = snd_usb_midi_v2_trigger,
+	.drain = snd_usb_midi_v2_drain,
+};
+
+static const struct snd_rawmidi_ops input_ops = {
+	.open = snd_usb_midi_v2_open,
+	.close = snd_usb_midi_v2_close,
+	.trigger = snd_usb_midi_v2_trigger,
+};
+
+/* create a USB MIDI 2.0 endpoint object */
+static int create_midi2_endpoint(struct snd_usb_midi2_interface *umidi,
+				 struct usb_host_endpoint *hostep,
+				 const struct usb_ms20_endpoint_descriptor *ms_ep)
+{
+	struct snd_usb_midi2_endpoint *ep;
+	int endpoint, dir;
+
+	usb_audio_dbg(umidi->chip, "Creating an EP 0x%02x, #GTB=%d\n",
+		      hostep->desc.bEndpointAddress,
+		      ms_ep->bNumGrpTrmBlock);
+
+	ep = kzalloc(sizeof(*ep), GFP_KERNEL);
+	if (!ep)
+		return -ENOMEM;
+
+	spin_lock_init(&ep->lock);
+	init_waitqueue_head(&ep->wait);
+	ep->dev = umidi->chip->dev;
+	endpoint = hostep->desc.bEndpointAddress;
+	dir = (endpoint & USB_DIR_IN) ? STR_IN : STR_OUT;
+
+	ep->endpoint = endpoint;
+	ep->direction = dir;
+	ep->ms_ep = ms_ep;
+	if (usb_endpoint_xfer_int(&hostep->desc))
+		ep->interval = hostep->desc.bInterval;
+	else
+		ep->interval = 0;
+	if (dir == STR_IN) {
+		if (ep->interval)
+			ep->pipe = usb_rcvintpipe(ep->dev, endpoint);
+		else
+			ep->pipe = usb_rcvbulkpipe(ep->dev, endpoint);
+	} else {
+		if (ep->interval)
+			ep->pipe = usb_sndintpipe(ep->dev, endpoint);
+		else
+			ep->pipe = usb_sndbulkpipe(ep->dev, endpoint);
+	}
+	ep->packets = usb_maxpacket(ep->dev, ep->pipe);
+	list_add_tail(&ep->list, &umidi->ep_list);
+
+	return 0;
+}
+
+/* destructor for endpoint; from snd_usb_midi_v2_free() */
+static void free_midi2_endpoint(struct snd_usb_midi2_endpoint *ep)
+{
+	list_del(&ep->list);
+	free_midi_urbs(ep);
+	kfree(ep);
+}
+
+/* call all endpoint destructors */
+static void free_all_midi2_endpoints(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_endpoint *ep;
+
+	while (!list_empty(&umidi->ep_list)) {
+		ep = list_first_entry(&umidi->ep_list,
+				      struct snd_usb_midi2_endpoint, list);
+		free_midi2_endpoint(ep);
+	}
+}
+
+/* find a MIDI STREAMING descriptor with a given subtype */
+static void *find_usb_ms_endpoint_descriptor(struct usb_host_endpoint *hostep,
+					     unsigned char subtype)
+{
+	unsigned char *extra = hostep->extra;
+	int extralen = hostep->extralen;
+
+	while (extralen > 3) {
+		struct usb_ms_endpoint_descriptor *ms_ep =
+			(struct usb_ms_endpoint_descriptor *)extra;
+
+		if (ms_ep->bLength > 3 &&
+		    ms_ep->bDescriptorType == USB_DT_CS_ENDPOINT &&
+		    ms_ep->bDescriptorSubtype == subtype)
+			return ms_ep;
+		if (!extra[0])
+			break;
+		extralen -= extra[0];
+		extra += extra[0];
+	}
+	return NULL;
+}
+
+/* get the full group terminal block descriptors and return the size */
+static int get_group_terminal_block_descs(struct snd_usb_midi2_interface *umidi)
+{
+	struct usb_host_interface *hostif = umidi->hostif;
+	struct usb_device *dev = umidi->chip->dev;
+	struct usb_ms20_gr_trm_block_header_descriptor header = { 0 };
+	unsigned char *data;
+	int err, size;
+
+	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
+			      USB_REQ_GET_DESCRIPTOR,
+			      USB_RECIP_INTERFACE | USB_TYPE_STANDARD | USB_DIR_IN,
+			      USB_DT_CS_GR_TRM_BLOCK << 8 | hostif->desc.bAlternateSetting,
+			      hostif->desc.bInterfaceNumber,
+			      &header, sizeof(header));
+	if (err < 0)
+		return err;
+	size = __le16_to_cpu(header.wTotalLength);
+	if (!size) {
+		dev_err(&dev->dev, "Failed to get GTB descriptors for %d:%d\n",
+			hostif->desc.bInterfaceNumber, hostif->desc.bAlternateSetting);
+		return -EINVAL;
+	}
+
+	data = kzalloc(size, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0),
+			      USB_REQ_GET_DESCRIPTOR,
+			      USB_RECIP_INTERFACE | USB_TYPE_STANDARD | USB_DIR_IN,
+			      USB_DT_CS_GR_TRM_BLOCK << 8 | hostif->desc.bAlternateSetting,
+			      hostif->desc.bInterfaceNumber, data, size);
+	if (err < 0) {
+		kfree(data);
+		return err;
+	}
+
+	umidi->blk_descs = data;
+	umidi->blk_desc_size = size;
+	return 0;
+}
+
+/* find the corresponding group terminal block descriptor */
+static const struct usb_ms20_gr_trm_block_descriptor *
+find_group_terminal_block(struct snd_usb_midi2_interface *umidi, int id)
+{
+	const unsigned char *data = umidi->blk_descs;
+	int size = umidi->blk_desc_size;
+	const struct usb_ms20_gr_trm_block_descriptor *desc;
+
+	size -= sizeof(struct usb_ms20_gr_trm_block_header_descriptor);
+	data += sizeof(struct usb_ms20_gr_trm_block_header_descriptor);
+	while (size > 0 && *data && *data <= size) {
+		desc = (const struct usb_ms20_gr_trm_block_descriptor *)data;
+		if (desc->bLength >= sizeof(*desc) &&
+		    desc->bDescriptorType == USB_DT_CS_GR_TRM_BLOCK &&
+		    desc->bDescriptorSubtype == USB_MS_GR_TRM_BLOCK &&
+		    desc->bGrpTrmBlkID == id)
+			return desc;
+		size -= *data;
+		data += *data;
+	}
+
+	return NULL;
+}
+
+/* fill up the information from GTB */
+static int parse_group_terminal_block(struct snd_usb_midi2_ump *rmidi,
+				      const struct usb_ms20_gr_trm_block_descriptor *desc)
+{
+	struct snd_usb_audio *chip = rmidi->umidi->chip;
+	struct snd_ump_endpoint *ump = rmidi->ump;
+
+	usb_audio_dbg(chip,
+		      "GTB id %d: groups = %d / %d, type = %d\n",
+		      desc->bGrpTrmBlkID, desc->nGroupTrm, desc->nNumGroupTrm,
+		      desc->bGrpTrmBlkType);
+
+	/* set default protocol */
+	switch (desc->bMIDIProtocol) {
+	case USB_MS_MIDI_PROTO_1_0_64:
+	case USB_MS_MIDI_PROTO_1_0_64_JRTS:
+	case USB_MS_MIDI_PROTO_1_0_128:
+	case USB_MS_MIDI_PROTO_1_0_128_JRTS:
+		ump->info.protocol = SNDRV_UMP_EP_INFO_PROTO_MIDI1;
+		break;
+	case USB_MS_MIDI_PROTO_2_0:
+	case USB_MS_MIDI_PROTO_2_0_JRTS:
+		ump->info.protocol = SNDRV_UMP_EP_INFO_PROTO_MIDI2;
+		break;
+	}
+
+	ump->info.protocol_caps = ump->info.protocol;
+	switch (desc->bMIDIProtocol) {
+	case USB_MS_MIDI_PROTO_1_0_64_JRTS:
+	case USB_MS_MIDI_PROTO_1_0_128_JRTS:
+	case USB_MS_MIDI_PROTO_2_0_JRTS:
+		ump->info.protocol_caps |= SNDRV_UMP_EP_INFO_PROTO_JRTS_TX |
+			SNDRV_UMP_EP_INFO_PROTO_JRTS_RX;
+		break;
+	}
+
+	return 0;
+}
+
+/* allocate and parse for each assigned group terminal block */
+static int parse_group_terminal_blocks(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_ump *rmidi;
+	const struct usb_ms20_gr_trm_block_descriptor *desc;
+	int err;
+
+	err = get_group_terminal_block_descs(umidi);
+	if (err < 0)
+		return err;
+	if (!umidi->blk_descs)
+		return 0;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		desc = find_group_terminal_block(umidi, rmidi->usb_block_id);
+		if (!desc)
+			continue;
+		err = parse_group_terminal_block(rmidi, desc);
+		if (err < 0)
+			return err;
+	}
+
+	return 0;
+}
+
+/* parse endpoints included in the given interface and create objects */
+static int parse_midi_2_0_endpoints(struct snd_usb_midi2_interface *umidi)
+{
+	struct usb_host_interface *hostif = umidi->hostif;
+	struct usb_host_endpoint *hostep;
+	struct usb_ms20_endpoint_descriptor *ms_ep;
+	int i, err;
+
+	for (i = 0; i < hostif->desc.bNumEndpoints; i++) {
+		hostep = &hostif->endpoint[i];
+		if (!usb_endpoint_xfer_bulk(&hostep->desc) &&
+		    !usb_endpoint_xfer_int(&hostep->desc))
+			continue;
+		ms_ep = find_usb_ms_endpoint_descriptor(hostep, USB_MS_GENERAL_2_0);
+		if (!ms_ep)
+			continue;
+		if (ms_ep->bLength <= sizeof(*ms_ep))
+			continue;
+		if (!ms_ep->bNumGrpTrmBlock)
+			continue;
+		if (ms_ep->bLength < sizeof(*ms_ep) + ms_ep->bNumGrpTrmBlock)
+			continue;
+		err = create_midi2_endpoint(umidi, hostep, ms_ep);
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}
+
+static void free_all_midi2_umps(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_ump *rmidi;
+
+	while (!list_empty(&umidi->rawmidi_list)) {
+		rmidi = list_first_entry(&umidi->rawmidi_list,
+					 struct snd_usb_midi2_ump, list);
+		list_del(&rmidi->list);
+		kfree(rmidi);
+	}
+}
+
+static int create_midi2_ump(struct snd_usb_midi2_interface *umidi,
+			    struct snd_usb_midi2_endpoint *ep_in,
+			    struct snd_usb_midi2_endpoint *ep_out,
+			    int blk_id)
+{
+	struct snd_usb_midi2_ump *rmidi;
+	struct snd_ump_endpoint *ump;
+	int input, output;
+	char idstr[16];
+	int err;
+
+	rmidi = kzalloc(sizeof(*rmidi), GFP_KERNEL);
+	if (!rmidi)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&rmidi->list);
+	rmidi->dev = umidi->chip->dev;
+	rmidi->umidi = umidi;
+	rmidi->usb_block_id = blk_id;
+
+	rmidi->index = umidi->chip->num_rawmidis;
+	snprintf(idstr, sizeof(idstr), "UMP %d", rmidi->index);
+	input = ep_in ? 1 : 0;
+	output = ep_out ? 1 : 0;
+	err = snd_ump_endpoint_new(umidi->chip->card, idstr, rmidi->index,
+				   output, input, &ump);
+	if (err < 0) {
+		usb_audio_dbg(umidi->chip, "Failed to create a UMP object\n");
+		kfree(rmidi);
+		return err;
+	}
+
+	rmidi->ump = ump;
+	umidi->chip->num_rawmidis++;
+
+	ump->private_data = rmidi;
+
+	if (input)
+		snd_rawmidi_set_ops(&ump->core, SNDRV_RAWMIDI_STREAM_INPUT,
+				    &input_ops);
+	if (output)
+		snd_rawmidi_set_ops(&ump->core, SNDRV_RAWMIDI_STREAM_OUTPUT,
+				    &output_ops);
+
+	rmidi->eps[STR_IN] = ep_in;
+	rmidi->eps[STR_OUT] = ep_out;
+	if (ep_in) {
+		ep_in->pair = ep_out;
+		ep_in->rmidi = rmidi;
+	}
+	if (ep_out) {
+		ep_out->pair = ep_in;
+		ep_out->rmidi = rmidi;
+	}
+
+	list_add_tail(&rmidi->list, &umidi->rawmidi_list);
+	return 0;
+}
+
+/* find the UMP EP with the given USB block id */
+static struct snd_usb_midi2_ump *
+find_midi2_ump(struct snd_usb_midi2_interface *umidi, int blk_id)
+{
+	struct snd_usb_midi2_ump *rmidi;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		if (rmidi->usb_block_id == blk_id)
+			return rmidi;
+	}
+	return NULL;
+}
+
+/* look for the matching output endpoint and create UMP object if found */
+static int find_matching_ep_partner(struct snd_usb_midi2_interface *umidi,
+				    struct snd_usb_midi2_endpoint *ep,
+				    int blk_id)
+{
+	struct snd_usb_midi2_endpoint *pair_ep;
+	int blk;
+
+	usb_audio_dbg(umidi->chip, "Looking for a pair for EP-in 0x%02x\n",
+		      ep->endpoint);
+	list_for_each_entry(pair_ep, &umidi->ep_list, list) {
+		if (pair_ep->direction != STR_OUT)
+			continue;
+		if (pair_ep->pair)
+			continue; /* already paired */
+		for (blk = 0; blk < pair_ep->ms_ep->bNumGrpTrmBlock; blk++) {
+			if (pair_ep->ms_ep->baAssoGrpTrmBlkID[blk] == blk_id) {
+				usb_audio_dbg(umidi->chip,
+					      "Found a match with EP-out 0x%02x blk %d\n",
+					      pair_ep->endpoint, blk);
+				return create_midi2_ump(umidi, ep, pair_ep, blk_id);
+			}
+		}
+	}
+	return 0;
+}
+
+static void snd_usb_midi_v2_free(struct snd_usb_midi2_interface *umidi)
+{
+	free_all_midi2_endpoints(umidi);
+	free_all_midi2_umps(umidi);
+	list_del(&umidi->list);
+	kfree(umidi->blk_descs);
+	kfree(umidi);
+}
+
+/* parse the interface for MIDI 2.0 */
+static int parse_midi_2_0(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_endpoint *ep;
+	int blk, id, err;
+
+	/* First, create an object for each USB MIDI Endpoint */
+	err = parse_midi_2_0_endpoints(umidi);
+	if (err < 0)
+		return err;
+	if (list_empty(&umidi->ep_list)) {
+		usb_audio_warn(umidi->chip, "No MIDI endpoints found\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Next, look for EP I/O pairs that are found in group terminal blocks
+	 * A UMP object is created for each EP I/O pair as bidirecitonal
+	 * UMP EP
+	 */
+	list_for_each_entry(ep, &umidi->ep_list, list) {
+		/* only input in this loop; output is matched in find_midi_ump() */
+		if (ep->direction != STR_IN)
+			continue;
+		for (blk = 0; blk < ep->ms_ep->bNumGrpTrmBlock; blk++) {
+			id = ep->ms_ep->baAssoGrpTrmBlkID[blk];
+			err = find_matching_ep_partner(umidi, ep, id);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	/*
+	 * For the remaining EPs, treat as singles, create a UMP object with
+	 * unidirectional EP
+	 */
+	list_for_each_entry(ep, &umidi->ep_list, list) {
+		if (ep->rmidi)
+			continue; /* already paired */
+		for (blk = 0; blk < ep->ms_ep->bNumGrpTrmBlock; blk++) {
+			id = ep->ms_ep->baAssoGrpTrmBlkID[blk];
+			if (find_midi2_ump(umidi, id))
+				continue;
+			usb_audio_dbg(umidi->chip,
+				      "Creating a unidirection UMP for EP=0x%02x, blk=%d\n",
+				      ep->endpoint, id);
+			if (ep->direction == STR_IN)
+				err = create_midi2_ump(umidi, ep, NULL, id);
+			else
+				err = create_midi2_ump(umidi, NULL, ep, id);
+			if (err < 0)
+				return err;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+/* is the given interface for MIDI 2.0? */
+static bool is_midi2_altset(struct usb_host_interface *hostif)
+{
+	struct usb_ms_header_descriptor *ms_header =
+		(struct usb_ms_header_descriptor *)hostif->extra;
+
+	if (hostif->extralen < 7 ||
+	    ms_header->bLength < 7 ||
+	    ms_header->bDescriptorType != USB_DT_CS_INTERFACE ||
+	    ms_header->bDescriptorSubtype != UAC_HEADER)
+		return false;
+
+	return le16_to_cpu(ms_header->bcdMSC) == USB_MS_REV_MIDI_2_0;
+}
+
+/* change the altsetting */
+static int set_altset(struct snd_usb_midi2_interface *umidi)
+{
+	usb_audio_dbg(umidi->chip, "Setting host iface %d:%d\n",
+		      umidi->hostif->desc.bInterfaceNumber,
+		      umidi->hostif->desc.bAlternateSetting);
+	return usb_set_interface(umidi->chip->dev,
+				 umidi->hostif->desc.bInterfaceNumber,
+				 umidi->hostif->desc.bAlternateSetting);
+}
+
+/* fill the fallback name string for each rawmidi instance */
+static void set_fallback_rawmidi_names(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_ump *rmidi;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		if (!*rmidi->ump->core.name)
+			sprintf(rmidi->ump->core.name, "USB MIDI %d",
+				rmidi->index);
+	}
+}
+
+/* create MIDI interface; fallback to MIDI 1.0 if needed */
+int snd_usb_midi_v2_create(struct snd_usb_audio *chip,
+			   struct usb_interface *iface,
+			   const struct snd_usb_audio_quirk *quirk,
+			   unsigned int usb_id)
+{
+	struct snd_usb_midi2_interface *umidi;
+	struct usb_host_interface *hostif;
+	int err;
+
+	usb_audio_dbg(chip, "Parsing interface %d...\n",
+		      iface->altsetting[0].desc.bInterfaceNumber);
+
+	/* fallback to MIDI 1.0? */
+	if (!midi2_enable) {
+		usb_audio_info(chip, "Falling back to MIDI 1.0 by module option\n");
+		goto fallback_to_midi1;
+	}
+	if ((quirk && quirk->type != QUIRK_MIDI_STANDARD_INTERFACE) ||
+	    iface->num_altsetting < 2) {
+		usb_audio_info(chip, "Quirk or no altest; falling back to MIDI 1.0\n");
+		goto fallback_to_midi1;
+	}
+	hostif = &iface->altsetting[1];
+	if (!is_midi2_altset(hostif)) {
+		usb_audio_info(chip, "No MIDI 2.0 at altset 1, falling back to MIDI 1.0\n");
+		goto fallback_to_midi1;
+	}
+	if (!hostif->desc.bNumEndpoints) {
+		usb_audio_info(chip, "No endpoint at altset 1, falling back to MIDI 1.0\n");
+		goto fallback_to_midi1;
+	}
+
+	usb_audio_dbg(chip, "Creating a MIDI 2.0 instance for %d:%d\n",
+		      hostif->desc.bInterfaceNumber,
+		      hostif->desc.bAlternateSetting);
+
+	umidi = kzalloc(sizeof(*umidi), GFP_KERNEL);
+	if (!umidi)
+		return -ENOMEM;
+	umidi->chip = chip;
+	umidi->iface = iface;
+	umidi->hostif = hostif;
+	INIT_LIST_HEAD(&umidi->rawmidi_list);
+	INIT_LIST_HEAD(&umidi->ep_list);
+
+	list_add_tail(&umidi->list, &chip->midi_v2_list);
+
+	err = set_altset(umidi);
+	if (err < 0) {
+		usb_audio_err(chip, "Failed to set altset\n");
+		goto error;
+	}
+
+	/* assume only altset 1 corresponding to MIDI 2.0 interface */
+	err = parse_midi_2_0(umidi);
+	if (err < 0) {
+		usb_audio_err(chip, "Failed to parse MIDI 2.0 interface\n");
+		goto error;
+	}
+
+	/* parse USB group terminal blocks */
+	err = parse_group_terminal_blocks(umidi);
+	if (err < 0) {
+		usb_audio_err(chip, "Failed to parse GTB\n");
+		goto error;
+	}
+
+	err = start_input_streams(umidi);
+	if (err < 0) {
+		usb_audio_err(chip, "Failed to start input streams\n");
+		goto error;
+	}
+
+	set_fallback_rawmidi_names(umidi);
+	return 0;
+
+ error:
+	snd_usb_midi_v2_free(umidi);
+	return err;
+
+ fallback_to_midi1:
+	return __snd_usbmidi_create(chip->card, iface, &chip->midi_list,
+				    quirk, usb_id, &chip->num_rawmidis);
+}
+
+static void suspend_midi2_endpoint(struct snd_usb_midi2_endpoint *ep)
+{
+	kill_midi_urbs(ep, true);
+	drain_urb_queue(ep);
+}
+
+void snd_usb_midi_v2_suspend_all(struct snd_usb_audio *chip)
+{
+	struct snd_usb_midi2_interface *umidi;
+	struct snd_usb_midi2_endpoint *ep;
+
+	list_for_each_entry(umidi, &chip->midi_v2_list, list) {
+		list_for_each_entry(ep, &umidi->ep_list, list)
+			suspend_midi2_endpoint(ep);
+	}
+}
+
+static void resume_midi2_endpoint(struct snd_usb_midi2_endpoint *ep)
+{
+	ep->running = ep->suspended;
+	if (ep->direction == STR_IN)
+		submit_io_urbs(ep);
+	/* FIXME: does it all? */
+}
+
+void snd_usb_midi_v2_resume_all(struct snd_usb_audio *chip)
+{
+	struct snd_usb_midi2_interface *umidi;
+	struct snd_usb_midi2_endpoint *ep;
+
+	list_for_each_entry(umidi, &chip->midi_v2_list, list) {
+		set_altset(umidi);
+		list_for_each_entry(ep, &umidi->ep_list, list)
+			resume_midi2_endpoint(ep);
+	}
+}
+
+void snd_usb_midi_v2_disconnect_all(struct snd_usb_audio *chip)
+{
+	struct snd_usb_midi2_interface *umidi;
+	struct snd_usb_midi2_endpoint *ep;
+
+	list_for_each_entry(umidi, &chip->midi_v2_list, list) {
+		umidi->disconnected = 1;
+		list_for_each_entry(ep, &umidi->ep_list, list) {
+			ep->disconnected = 1;
+			kill_midi_urbs(ep, false);
+			drain_urb_queue(ep);
+		}
+	}
+}
+
+/* release the MIDI instance */
+void snd_usb_midi_v2_free_all(struct snd_usb_audio *chip)
+{
+	struct snd_usb_midi2_interface *umidi, *next;
+
+	list_for_each_entry_safe(umidi, next, &chip->midi_v2_list, list)
+		snd_usb_midi_v2_free(umidi);
+}
diff --git a/sound/usb/midi2.h b/sound/usb/midi2.h
new file mode 100644
index 000000000000..94a65fcbd58b
--- /dev/null
+++ b/sound/usb/midi2.h
@@ -0,0 +1,33 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef __USB_AUDIO_MIDI2_H
+#define __USB_AUDIO_MIDI2_H
+
+#include "midi.h"
+
+#if IS_ENABLED(CONFIG_SND_USB_AUDIO_MIDI_V2)
+int snd_usb_midi_v2_create(struct snd_usb_audio *chip,
+			   struct usb_interface *iface,
+			   const struct snd_usb_audio_quirk *quirk,
+			   unsigned int usb_id);
+void snd_usb_midi_v2_suspend_all(struct snd_usb_audio *chip);
+void snd_usb_midi_v2_resume_all(struct snd_usb_audio *chip);
+void snd_usb_midi_v2_disconnect_all(struct snd_usb_audio *chip);
+void snd_usb_midi_v2_free_all(struct snd_usb_audio *chip);
+#else /* CONFIG_SND_USB_AUDIO_MIDI_V2 */
+/* fallback to MIDI 1.0 creation */
+static inline int snd_usb_midi_v2_create(struct snd_usb_audio *chip,
+					 struct usb_interface *iface,
+					 const struct snd_usb_audio_quirk *quirk,
+					 unsigned int usb_id)
+{
+	return __snd_usbmidi_create(chip->card, iface, &chip->midi_list,
+				    quirk, usb_id, &chip->num_rawmidis);
+}
+
+static inline void snd_usb_midi_v2_suspend_all(struct snd_usb_audio *chip) {}
+static inline void snd_usb_midi_v2_resume_all(struct snd_usb_audio *chip) {}
+static inline void snd_usb_midi_v2_disconnect_all(struct snd_usb_audio *chip) {}
+static inline void snd_usb_midi_v2_free_all(struct snd_usb_audio *chip) {}
+#endif /* CONFIG_SND_USB_AUDIO_MIDI_V2 */
+
+#endif /* __USB_AUDIO_MIDI2_H */
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 1cabe4cc019f..53e079e91580 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -19,6 +19,7 @@ 
 #include "mixer.h"
 #include "mixer_quirks.h"
 #include "midi.h"
+#include "midi2.h"
 #include "quirks.h"
 #include "helper.h"
 #include "endpoint.h"
@@ -80,7 +81,7 @@  static int create_any_midi_quirk(struct snd_usb_audio *chip,
 				 struct usb_driver *driver,
 				 const struct snd_usb_audio_quirk *quirk)
 {
-	return snd_usbmidi_create(chip->card, intf, &chip->midi_list, quirk);
+	return snd_usb_midi_v2_create(chip, intf, quirk, 0);
 }
 
 /*
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index b1fa0a377866..43d4029edab4 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -51,6 +51,7 @@  struct snd_usb_audio {
 
 	unsigned int num_rawmidis;	/* number of created rawmidi devices */
 	struct list_head midi_list;	/* list of midi interfaces */
+	struct list_head midi_v2_list;	/* list of MIDI 2 interfaces */
 
 	struct list_head mixer_list;	/* list of mixer interfaces */