Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1234 insertions, 0 deletions

diff --git a/sound/usb/midi2.c b/sound/usb/midi2.c
new file mode 100644
index 0000000000..1ec177fe28
--- /dev/null
+++ b/sound/usb/midi2.c
@@ -0,0 +1,1234 @@
+// 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.");
+
+static bool midi2_ump_probe = true;
+module_param(midi2_ump_probe, bool, 0444);
+MODULE_PARM_DESC(midi2_ump_probe, "Probe UMP v1.1 support at first.");
+
+/* 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 pair */
+	struct snd_ump_endpoint *ump;		/* 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 */
+	bool ump_parsed;			/* Parsed UMP 1.1 EP/FB info*/
+	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;
+
+	count = snd_ump_transmit(ep->ump, urb->transfer_buffer,
+				 ep->packets);
+	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) {
+		le32_to_cpu_array((u32 *)urb->transfer_buffer, len >> 2);
+		snd_ump_receive(ep->ump, (u32 *)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 < 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 */
+/* the callers should handle allocation errors via free_midi_urbs() */
+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 *
+ump_to_endpoint(struct snd_ump_endpoint *ump, int dir)
+{
+	struct snd_usb_midi2_ump *rmidi = ump->private_data;
+
+	return rmidi->eps[dir];
+}
+
+/* ump open callback */
+static int snd_usb_midi_v2_open(struct snd_ump_endpoint *ump, int dir)
+{
+	struct snd_usb_midi2_endpoint *ep = ump_to_endpoint(ump, dir);
+	int err = 0;
+
+	if (!ep || !ep->endpoint)
+		return -ENODEV;
+	if (ep->disconnected)
+		return -EIO;
+	if (ep->direction == STR_OUT) {
+		err = alloc_midi_urbs(ep);
+		if (err) {
+			free_midi_urbs(ep);
+			return err;
+		}
+	}
+	return 0;
+}
+
+/* ump close callback */
+static void snd_usb_midi_v2_close(struct snd_ump_endpoint *ump, int dir)
+{
+	struct snd_usb_midi2_endpoint *ep = ump_to_endpoint(ump, dir);
+
+	if (ep->direction == STR_OUT) {
+		kill_midi_urbs(ep, false);
+		drain_urb_queue(ep);
+		free_midi_urbs(ep);
+	}
+}
+
+/* ump trigger callback */
+static void snd_usb_midi_v2_trigger(struct snd_ump_endpoint *ump, int dir,
+				    int up)
+{
+	struct snd_usb_midi2_endpoint *ep = ump_to_endpoint(ump, dir);
+
+	atomic_set(&ep->running, up);
+	if (up && ep->direction == STR_OUT && !ep->disconnected)
+		submit_io_urbs(ep);
+}
+
+/* ump drain callback */
+static void snd_usb_midi_v2_drain(struct snd_ump_endpoint *ump, int dir)
+{
+	struct snd_usb_midi2_endpoint *ep = ump_to_endpoint(ump, dir);
+
+	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_ump_ops snd_usb_midi_v2_ump_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,
+};
+
+/* 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_ump_endpoint *ump = rmidi->ump;
+	unsigned int protocol, protocol_caps;
+
+	/* 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:
+		protocol = SNDRV_UMP_EP_INFO_PROTO_MIDI1;
+		break;
+	case USB_MS_MIDI_PROTO_2_0:
+	case USB_MS_MIDI_PROTO_2_0_JRTS:
+		protocol = SNDRV_UMP_EP_INFO_PROTO_MIDI2;
+		break;
+	default:
+		return 0;
+	}
+
+	if (ump->info.protocol && ump->info.protocol != protocol)
+		usb_audio_info(rmidi->umidi->chip,
+			       "Overriding preferred MIDI protocol in GTB %d: %x -> %x\n",
+			       rmidi->usb_block_id, ump->info.protocol,
+			       protocol);
+	ump->info.protocol = protocol;
+
+	protocol_caps = 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:
+		protocol_caps |= SNDRV_UMP_EP_INFO_PROTO_JRTS_TX |
+			SNDRV_UMP_EP_INFO_PROTO_JRTS_RX;
+		break;
+	}
+
+	if (ump->info.protocol_caps && ump->info.protocol_caps != protocol_caps)
+		usb_audio_info(rmidi->umidi->chip,
+			       "Overriding MIDI protocol caps in GTB %d: %x -> %x\n",
+			       rmidi->usb_block_id, ump->info.protocol_caps,
+			       protocol_caps);
+	ump->info.protocol_caps = protocol_caps;
+
+	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;
+	ump->ops = &snd_usb_midi_v2_ump_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;
+		ep_in->ump = ump;
+	}
+	if (ep_out) {
+		ep_out->pair = ep_in;
+		ep_out->rmidi = rmidi;
+		ep_out->ump = ump;
+	}
+
+	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;
+}
+
+/* Call UMP helper to parse UMP endpoints;
+ * this needs to be called after starting the input streams for bi-directional
+ * communications
+ */
+static int parse_ump_endpoints(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_ump *rmidi;
+	int err;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		if (!rmidi->ump ||
+		    !(rmidi->ump->core.info_flags & SNDRV_RAWMIDI_INFO_DUPLEX))
+			continue;
+		err = snd_ump_parse_endpoint(rmidi->ump);
+		if (!err) {
+			rmidi->ump_parsed = true;
+		} else {
+			if (err == -ENOMEM)
+				return err;
+			/* fall back to GTB later */
+		}
+	}
+	return 0;
+}
+
+/* create a UMP block from a GTB entry */
+static int create_gtb_block(struct snd_usb_midi2_ump *rmidi, int dir, int blk)
+{
+	struct snd_usb_midi2_interface *umidi = rmidi->umidi;
+	const struct usb_ms20_gr_trm_block_descriptor *desc;
+	struct snd_ump_block *fb;
+	int type, err;
+
+	desc = find_group_terminal_block(umidi, blk);
+	if (!desc)
+		return 0;
+
+	usb_audio_dbg(umidi->chip,
+		      "GTB %d: type=%d, group=%d/%d, protocol=%d, in bw=%d, out bw=%d\n",
+		      blk, desc->bGrpTrmBlkType, desc->nGroupTrm,
+		      desc->nNumGroupTrm, desc->bMIDIProtocol,
+		      __le16_to_cpu(desc->wMaxInputBandwidth),
+		      __le16_to_cpu(desc->wMaxOutputBandwidth));
+
+	/* assign the direction */
+	switch (desc->bGrpTrmBlkType) {
+	case USB_MS_GR_TRM_BLOCK_TYPE_BIDIRECTIONAL:
+		type = SNDRV_UMP_DIR_BIDIRECTION;
+		break;
+	case USB_MS_GR_TRM_BLOCK_TYPE_INPUT_ONLY:
+		type = SNDRV_UMP_DIR_INPUT;
+		break;
+	case USB_MS_GR_TRM_BLOCK_TYPE_OUTPUT_ONLY:
+		type = SNDRV_UMP_DIR_OUTPUT;
+		break;
+	default:
+		usb_audio_dbg(umidi->chip, "Unsupported GTB type %d\n",
+			      desc->bGrpTrmBlkType);
+		return 0; /* unsupported */
+	}
+
+	/* guess work: set blk-1 as the (0-based) block ID */
+	err = snd_ump_block_new(rmidi->ump, blk - 1, type,
+				desc->nGroupTrm, desc->nNumGroupTrm,
+				&fb);
+	if (err == -EBUSY)
+		return 0; /* already present */
+	else if (err)
+		return err;
+
+	if (desc->iBlockItem)
+		usb_string(rmidi->dev, desc->iBlockItem,
+			   fb->info.name, sizeof(fb->info.name));
+
+	if (__le16_to_cpu(desc->wMaxInputBandwidth) == 1 ||
+	    __le16_to_cpu(desc->wMaxOutputBandwidth) == 1)
+		fb->info.flags |= SNDRV_UMP_BLOCK_IS_MIDI1 |
+			SNDRV_UMP_BLOCK_IS_LOWSPEED;
+
+	usb_audio_dbg(umidi->chip,
+		      "Created a UMP block %d from GTB, name=%s\n",
+		      blk, fb->info.name);
+	return 0;
+}
+
+/* Create UMP blocks for each UMP EP */
+static int create_blocks_from_gtb(struct snd_usb_midi2_interface *umidi)
+{
+	struct snd_usb_midi2_ump *rmidi;
+	int i, blk, err, dir;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		if (!rmidi->ump)
+			continue;
+		/* Blocks have been already created? */
+		if (rmidi->ump_parsed || rmidi->ump->info.num_blocks)
+			continue;
+		/* GTB is static-only */
+		rmidi->ump->info.flags |= SNDRV_UMP_EP_INFO_STATIC_BLOCKS;
+		/* loop over GTBs */
+		for (dir = 0; dir < 2; dir++) {
+			if (!rmidi->eps[dir])
+				continue;
+			for (i = 0; i < rmidi->eps[dir]->ms_ep->bNumGrpTrmBlock; i++) {
+				blk = rmidi->eps[dir]->ms_ep->baAssoGrpTrmBlkID[i];
+				err = create_gtb_block(rmidi, dir, blk);
+				if (err < 0)
+					return err;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/* attach legacy rawmidis */
+static int attach_legacy_rawmidi(struct snd_usb_midi2_interface *umidi)
+{
+#if IS_ENABLED(CONFIG_SND_UMP_LEGACY_RAWMIDI)
+	struct snd_usb_midi2_ump *rmidi;
+	int err;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		err = snd_ump_attach_legacy_rawmidi(rmidi->ump,
+						    "Legacy MIDI",
+						    umidi->chip->num_rawmidis);
+		if (err < 0)
+			return err;
+		umidi->chip->num_rawmidis++;
+	}
+#endif
+	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 UMP Endpoint name string from USB descriptor */
+static void fill_ump_ep_name(struct snd_ump_endpoint *ump,
+			     struct usb_device *dev, int id)
+{
+	int len;
+
+	usb_string(dev, id, ump->info.name, sizeof(ump->info.name));
+
+	/* trim superfluous "MIDI" suffix */
+	len = strlen(ump->info.name);
+	if (len > 5 && !strcmp(ump->info.name + len - 5, " MIDI"))
+		ump->info.name[len - 5] = 0;
+}
+
+/* fill the fallback name string for each rawmidi instance */
+static void set_fallback_rawmidi_names(struct snd_usb_midi2_interface *umidi)
+{
+	struct usb_device *dev = umidi->chip->dev;
+	struct snd_usb_midi2_ump *rmidi;
+	struct snd_ump_endpoint *ump;
+
+	list_for_each_entry(rmidi, &umidi->rawmidi_list, list) {
+		ump = rmidi->ump;
+		/* fill UMP EP name from USB descriptors */
+		if (!*ump->info.name && umidi->hostif->desc.iInterface)
+			fill_ump_ep_name(ump, dev, umidi->hostif->desc.iInterface);
+		else if (!*ump->info.name && dev->descriptor.iProduct)
+			fill_ump_ep_name(ump, dev, dev->descriptor.iProduct);
+		/* fill fallback name */
+		if (!*ump->info.name)
+			sprintf(ump->info.name, "USB MIDI %d", rmidi->index);
+		/* copy as rawmidi name if not set */
+		if (!*ump->core.name)
+			strscpy(ump->core.name, ump->info.name,
+				sizeof(ump->core.name));
+		/* use serial number string as unique UMP product id */
+		if (!*ump->info.product_id && dev->descriptor.iSerialNumber)
+			usb_string(dev, dev->descriptor.iSerialNumber,
+				   ump->info.product_id,
+				   sizeof(ump->info.product_id));
+	}
+}
+
+/* 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;
+	}
+
+	if (midi2_ump_probe) {
+		err = parse_ump_endpoints(umidi);
+		if (err < 0) {
+			usb_audio_err(chip, "Failed to parse UMP endpoint\n");
+			goto error;
+		}
+	}
+
+	err = create_blocks_from_gtb(umidi);
+	if (err < 0) {
+		usb_audio_err(chip, "Failed to create GTB blocks\n");
+		goto error;
+	}
+
+	set_fallback_rawmidi_names(umidi);
+
+	err = attach_legacy_rawmidi(umidi);
+	if (err < 0) {
+		usb_audio_err(chip, "Failed to create legacy rawmidi\n");
+		goto error;
+	}
+
+	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);
+}