treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

22 files changed, 7479 insertions, 0 deletions

diff --git a/sound/usb/usx2y/Makefile b/sound/usb/usx2y/Makefile
new file mode 100644
index 000000000..9db87ae39
--- /dev/null
+++ b/sound/usb/usx2y/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+snd-usb-usx2y-y := usbusx2y.o usX2Yhwdep.o usx2yhwdeppcm.o
+snd-usb-us122l-y := us122l.o
+snd-usb-us144mkii-y := us144mkii.o us144mkii_pcm.o us144mkii_playback.o us144mkii_capture.o us144mkii_midi.o us144mkii_controls.o
+
+obj-$(CONFIG_SND_USB_USX2Y) += snd-usb-usx2y.o
+obj-$(CONFIG_SND_USB_US122L) += snd-usb-us122l.o
+obj-$(CONFIG_SND_USB_US144MKII) += snd-usb-us144mkii.o
\ No newline at end of file
diff --git a/sound/usb/usx2y/us122l.c b/sound/usb/usx2y/us122l.c
new file mode 100644
index 000000000..f00b53346
--- /dev/null
+++ b/sound/usb/usx2y/us122l.c
@@ -0,0 +1,682 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
+ */
+
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/hwdep.h>
+#include <sound/pcm.h>
+#include <sound/initval.h>
+#define MODNAME "US122L"
+#include "usb_stream.c"
+#include "../usbaudio.h"
+#include "../midi.h"
+#include "us122l.h"
+
+MODULE_AUTHOR("Karsten Wiese <fzu@wemgehoertderstaat.de>");
+MODULE_DESCRIPTION("TASCAM "NAME_ALLCAPS" Version 0.5");
+MODULE_LICENSE("GPL");
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-max */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* Id for this card */
+							/* Enable this card */
+static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for "NAME_ALLCAPS".");
+module_param_array(id, charp, NULL, 0444);
+MODULE_PARM_DESC(id, "ID string for "NAME_ALLCAPS".");
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable "NAME_ALLCAPS".");
+
+/* driver_info flags */
+#define US122L_FLAG_US144	BIT(0)
+
+static int snd_us122l_card_used[SNDRV_CARDS];
+
+static int us122l_create_usbmidi(struct snd_card *card)
+{
+	static const struct snd_usb_midi_endpoint_info quirk_data = {
+		.out_ep = 4,
+		.in_ep = 3,
+		.out_cables =	0x001,
+		.in_cables =	0x001
+	};
+	static const struct snd_usb_audio_quirk quirk = {
+		.vendor_name =	"US122L",
+		.product_name =	NAME_ALLCAPS,
+		.ifnum =	1,
+		.type = QUIRK_MIDI_US122L,
+		.data = &quirk_data
+	};
+	struct usb_device *dev = US122L(card)->dev;
+	struct usb_interface *iface = usb_ifnum_to_if(dev, 1);
+
+	return snd_usbmidi_create(card, iface,
+				  &US122L(card)->midi_list, &quirk);
+}
+
+static int us144_create_usbmidi(struct snd_card *card)
+{
+	static const struct snd_usb_midi_endpoint_info quirk_data = {
+		.out_ep = 4,
+		.in_ep = 3,
+		.out_cables =	0x001,
+		.in_cables =	0x001
+	};
+	static const struct snd_usb_audio_quirk quirk = {
+		.vendor_name =	"US144",
+		.product_name =	NAME_ALLCAPS,
+		.ifnum =	0,
+		.type = QUIRK_MIDI_US122L,
+		.data = &quirk_data
+	};
+	struct usb_device *dev = US122L(card)->dev;
+	struct usb_interface *iface = usb_ifnum_to_if(dev, 0);
+
+	return snd_usbmidi_create(card, iface,
+				  &US122L(card)->midi_list, &quirk);
+}
+
+static void pt_info_set(struct usb_device *dev, u8 v)
+{
+	usb_control_msg_send(dev, 0, 'I',
+			     USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+			     v, 0, NULL, 0, 1000, GFP_NOIO);
+}
+
+static vm_fault_t usb_stream_hwdep_vm_fault(struct vm_fault *vmf)
+{
+	unsigned long offset;
+	struct page *page;
+	void *vaddr;
+	struct us122l *us122l = vmf->vma->vm_private_data;
+	struct usb_stream *s;
+
+	guard(mutex)(&us122l->mutex);
+	s = us122l->sk.s;
+	if (!s)
+		return VM_FAULT_SIGBUS;
+
+	offset = vmf->pgoff << PAGE_SHIFT;
+	if (offset < PAGE_ALIGN(s->read_size)) {
+		vaddr = (char *)s + offset;
+	} else {
+		offset -= PAGE_ALIGN(s->read_size);
+		if (offset >= PAGE_ALIGN(s->write_size))
+			return VM_FAULT_SIGBUS;
+
+		vaddr = us122l->sk.write_page + offset;
+	}
+	page = virt_to_page(vaddr);
+
+	get_page(page);
+
+	vmf->page = page;
+
+	return 0;
+}
+
+
+static const struct vm_operations_struct usb_stream_hwdep_vm_ops = {
+	.fault = usb_stream_hwdep_vm_fault,
+};
+
+static int usb_stream_hwdep_open(struct snd_hwdep *hw, struct file *file)
+{
+	struct us122l	*us122l = hw->private_data;
+	struct usb_interface *iface;
+
+	if (hw->used >= 2)
+		return -EBUSY;
+
+	if (!us122l->first)
+		us122l->first = file;
+
+	if (us122l->is_us144) {
+		iface = usb_ifnum_to_if(us122l->dev, 0);
+		usb_autopm_get_interface(iface);
+	}
+	iface = usb_ifnum_to_if(us122l->dev, 1);
+	usb_autopm_get_interface(iface);
+	return 0;
+}
+
+static int usb_stream_hwdep_release(struct snd_hwdep *hw, struct file *file)
+{
+	struct us122l	*us122l = hw->private_data;
+	struct usb_interface *iface;
+
+	if (us122l->is_us144) {
+		iface = usb_ifnum_to_if(us122l->dev, 0);
+		usb_autopm_put_interface(iface);
+	}
+	iface = usb_ifnum_to_if(us122l->dev, 1);
+	usb_autopm_put_interface(iface);
+	if (us122l->first == file)
+		us122l->first = NULL;
+	guard(mutex)(&us122l->mutex);
+	if (us122l->master == file)
+		us122l->master = us122l->slave;
+
+	us122l->slave = NULL;
+	return 0;
+}
+
+static int usb_stream_hwdep_mmap(struct snd_hwdep *hw,
+				 struct file *filp, struct vm_area_struct *area)
+{
+	unsigned long	size = area->vm_end - area->vm_start;
+	struct us122l	*us122l = hw->private_data;
+	unsigned long offset;
+	struct usb_stream *s;
+	bool read;
+
+	offset = area->vm_pgoff << PAGE_SHIFT;
+	guard(mutex)(&us122l->mutex);
+	s = us122l->sk.s;
+	read = offset < s->read_size;
+	if (read && area->vm_flags & VM_WRITE)
+		return -EPERM;
+	/* if userspace tries to mmap beyond end of our buffer, fail */
+	if (size > PAGE_ALIGN(read ? s->read_size : s->write_size)) {
+		dev_warn(hw->card->dev, "%s: size %lu > %u\n", __func__,
+			 size, read ? s->read_size : s->write_size);
+		return -EINVAL;
+	}
+
+	area->vm_ops = &usb_stream_hwdep_vm_ops;
+	vm_flags_set(area, VM_DONTDUMP);
+	if (!read)
+		vm_flags_set(area, VM_DONTEXPAND);
+	area->vm_private_data = us122l;
+	return 0;
+}
+
+static __poll_t usb_stream_hwdep_poll(struct snd_hwdep *hw,
+					  struct file *file, poll_table *wait)
+{
+	struct us122l	*us122l = hw->private_data;
+	unsigned int	*polled;
+	__poll_t	mask;
+
+	poll_wait(file, &us122l->sk.sleep, wait);
+
+	mask = EPOLLIN | EPOLLOUT | EPOLLWRNORM | EPOLLERR;
+	if (mutex_trylock(&us122l->mutex)) {
+		struct usb_stream *s = us122l->sk.s;
+
+		if (s && s->state == usb_stream_ready) {
+			if (us122l->first == file)
+				polled = &s->periods_polled;
+			else
+				polled = &us122l->second_periods_polled;
+			if (*polled != s->periods_done) {
+				*polled = s->periods_done;
+				mask = EPOLLIN | EPOLLOUT | EPOLLWRNORM;
+			} else {
+				mask = 0;
+			}
+		}
+		mutex_unlock(&us122l->mutex);
+	}
+	return mask;
+}
+
+static void us122l_stop(struct us122l *us122l)
+{
+	struct list_head *p;
+
+	list_for_each(p, &us122l->midi_list)
+		snd_usbmidi_input_stop(p);
+
+	usb_stream_stop(&us122l->sk);
+	usb_stream_free(&us122l->sk);
+}
+
+static int us122l_set_sample_rate(struct usb_device *dev, int rate)
+{
+	unsigned int ep = 0x81;
+	unsigned char data[3];
+	int err;
+
+	data[0] = rate;
+	data[1] = rate >> 8;
+	data[2] = rate >> 16;
+	err = usb_control_msg_send(dev, 0, UAC_SET_CUR,
+				   USB_TYPE_CLASS | USB_RECIP_ENDPOINT | USB_DIR_OUT,
+				   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, data, 3,
+				   1000, GFP_NOIO);
+	if (err)
+		dev_err(&dev->dev, "%d: cannot set freq %d to ep 0x%x\n",
+			dev->devnum, rate, ep);
+	return err;
+}
+
+static bool us122l_start(struct us122l *us122l,
+			 unsigned int rate, unsigned int period_frames)
+{
+	struct list_head *p;
+	int err;
+	unsigned int use_packsize = 0;
+	bool success = false;
+
+	if (us122l->dev->speed == USB_SPEED_HIGH) {
+		/* The us-122l's descriptor defaults to iso max_packsize 78,
+		   which isn't needed for samplerates <= 48000.
+		   Lets save some memory:
+		*/
+		switch (rate) {
+		case 44100:
+			use_packsize = 36;
+			break;
+		case 48000:
+			use_packsize = 42;
+			break;
+		case 88200:
+			use_packsize = 72;
+			break;
+		}
+	}
+	if (!usb_stream_new(&us122l->sk, us122l->dev, 1, 2,
+			    rate, use_packsize, period_frames, 6))
+		goto out;
+
+	err = us122l_set_sample_rate(us122l->dev, rate);
+	if (err < 0) {
+		us122l_stop(us122l);
+		dev_err(&us122l->dev->dev, "us122l_set_sample_rate error\n");
+		goto out;
+	}
+	err = usb_stream_start(&us122l->sk);
+	if (err < 0) {
+		us122l_stop(us122l);
+		dev_err(&us122l->dev->dev, "%s error %i\n", __func__, err);
+		goto out;
+	}
+	list_for_each(p, &us122l->midi_list)
+		snd_usbmidi_input_start(p);
+	success = true;
+out:
+	return success;
+}
+
+static int usb_stream_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
+				  unsigned int cmd, unsigned long arg)
+{
+	struct usb_stream_config cfg;
+	struct us122l *us122l = hw->private_data;
+	struct usb_stream *s;
+	unsigned int min_period_frames;
+	int err = 0;
+	bool high_speed;
+
+	if (cmd != SNDRV_USB_STREAM_IOCTL_SET_PARAMS)
+		return -ENOTTY;
+
+	if (copy_from_user(&cfg, (void __user *)arg, sizeof(cfg)))
+		return -EFAULT;
+
+	if (cfg.version != USB_STREAM_INTERFACE_VERSION)
+		return -ENXIO;
+
+	high_speed = us122l->dev->speed == USB_SPEED_HIGH;
+	if ((cfg.sample_rate != 44100 && cfg.sample_rate != 48000  &&
+	     (!high_speed ||
+	      (cfg.sample_rate != 88200 && cfg.sample_rate != 96000))) ||
+	    cfg.frame_size != 6 ||
+	    cfg.period_frames > 0x3000)
+		return -EINVAL;
+
+	switch (cfg.sample_rate) {
+	case 44100:
+		min_period_frames = 48;
+		break;
+	case 48000:
+		min_period_frames = 52;
+		break;
+	default:
+		min_period_frames = 104;
+		break;
+	}
+	if (!high_speed)
+		min_period_frames <<= 1;
+	if (cfg.period_frames < min_period_frames)
+		return -EINVAL;
+
+	snd_power_wait(hw->card);
+
+	guard(mutex)(&us122l->mutex);
+	s = us122l->sk.s;
+	if (!us122l->master) {
+		us122l->master = file;
+	} else if (us122l->master != file) {
+		if (!s || memcmp(&cfg, &s->cfg, sizeof(cfg))) {
+			err = -EIO;
+			goto unlock;
+		}
+		us122l->slave = file;
+	}
+	if (!s || memcmp(&cfg, &s->cfg, sizeof(cfg)) ||
+	    s->state == usb_stream_xrun) {
+		us122l_stop(us122l);
+		if (!us122l_start(us122l, cfg.sample_rate, cfg.period_frames))
+			err = -EIO;
+		else
+			err = 1;
+	}
+unlock:
+	wake_up_all(&us122l->sk.sleep);
+	return err;
+}
+
+#define SND_USB_STREAM_ID "USB STREAM"
+static int usb_stream_hwdep_new(struct snd_card *card)
+{
+	int err;
+	struct snd_hwdep *hw;
+	struct usb_device *dev = US122L(card)->dev;
+
+	err = snd_hwdep_new(card, SND_USB_STREAM_ID, 0, &hw);
+	if (err < 0)
+		return err;
+
+	hw->iface = SNDRV_HWDEP_IFACE_USB_STREAM;
+	hw->private_data = US122L(card);
+	hw->ops.open = usb_stream_hwdep_open;
+	hw->ops.release = usb_stream_hwdep_release;
+	hw->ops.ioctl = usb_stream_hwdep_ioctl;
+	hw->ops.ioctl_compat = usb_stream_hwdep_ioctl;
+	hw->ops.mmap = usb_stream_hwdep_mmap;
+	hw->ops.poll = usb_stream_hwdep_poll;
+
+	sprintf(hw->name, "/dev/bus/usb/%03d/%03d/hwdeppcm",
+		dev->bus->busnum, dev->devnum);
+	return 0;
+}
+
+static bool us122l_create_card(struct snd_card *card)
+{
+	int err;
+	struct us122l *us122l = US122L(card);
+
+	if (us122l->is_us144) {
+		err = usb_set_interface(us122l->dev, 0, 1);
+		if (err) {
+			dev_err(card->dev, "usb_set_interface error\n");
+			return false;
+		}
+	}
+	err = usb_set_interface(us122l->dev, 1, 1);
+	if (err) {
+		dev_err(card->dev, "usb_set_interface error\n");
+		return false;
+	}
+
+	pt_info_set(us122l->dev, 0x11);
+	pt_info_set(us122l->dev, 0x10);
+
+	if (!us122l_start(us122l, 44100, 256))
+		return false;
+
+	if (us122l->is_us144)
+		err = us144_create_usbmidi(card);
+	else
+		err = us122l_create_usbmidi(card);
+	if (err < 0) {
+		dev_err(card->dev, "us122l_create_usbmidi error %i\n", err);
+		goto stop;
+	}
+	err = usb_stream_hwdep_new(card);
+	if (err < 0) {
+		/* release the midi resources */
+		struct list_head *p;
+
+		list_for_each(p, &us122l->midi_list)
+			snd_usbmidi_disconnect(p);
+
+		goto stop;
+	}
+	return true;
+
+stop:
+	us122l_stop(us122l);
+	return false;
+}
+
+static void snd_us122l_free(struct snd_card *card)
+{
+	struct us122l	*us122l = US122L(card);
+	int		index = us122l->card_index;
+
+	if (index >= 0 && index < SNDRV_CARDS)
+		snd_us122l_card_used[index] = 0;
+}
+
+static int usx2y_create_card(struct usb_device *device,
+			     struct usb_interface *intf,
+			     struct snd_card **cardp,
+			     unsigned long flags)
+{
+	int		dev;
+	struct snd_card *card;
+	int err;
+
+	for (dev = 0; dev < SNDRV_CARDS; ++dev)
+		if (enable[dev] && !snd_us122l_card_used[dev])
+			break;
+	if (dev >= SNDRV_CARDS)
+		return -ENODEV;
+	err = snd_card_new(&intf->dev, index[dev], id[dev], THIS_MODULE,
+			   sizeof(struct us122l), &card);
+	if (err < 0)
+		return err;
+	snd_us122l_card_used[US122L(card)->card_index = dev] = 1;
+	card->private_free = snd_us122l_free;
+	US122L(card)->dev = device;
+	mutex_init(&US122L(card)->mutex);
+	US122L(card)->sk.dev = device;
+	init_waitqueue_head(&US122L(card)->sk.sleep);
+	US122L(card)->is_us144 = flags & US122L_FLAG_US144;
+	INIT_LIST_HEAD(&US122L(card)->midi_list);
+	strscpy(card->driver, "USB "NAME_ALLCAPS"");
+	sprintf(card->shortname, "TASCAM "NAME_ALLCAPS"");
+	sprintf(card->longname, "%s (%x:%x if %d at %03d/%03d)",
+		card->shortname,
+		le16_to_cpu(device->descriptor.idVendor),
+		le16_to_cpu(device->descriptor.idProduct),
+		0,
+		US122L(card)->dev->bus->busnum,
+		US122L(card)->dev->devnum
+		);
+	*cardp = card;
+	return 0;
+}
+
+static int us122l_usb_probe(struct usb_interface *intf,
+			    const struct usb_device_id *device_id,
+			    struct snd_card **cardp)
+{
+	struct usb_device *device = interface_to_usbdev(intf);
+	struct snd_card *card;
+	int err;
+
+	err = usx2y_create_card(device, intf, &card, device_id->driver_info);
+	if (err < 0)
+		return err;
+
+	if (!us122l_create_card(card)) {
+		snd_card_free(card);
+		return -EINVAL;
+	}
+
+	err = snd_card_register(card);
+	if (err < 0) {
+		snd_card_free(card);
+		return err;
+	}
+
+	*cardp = card;
+	return 0;
+}
+
+static int snd_us122l_probe(struct usb_interface *intf,
+			    const struct usb_device_id *id)
+{
+	struct usb_device *device = interface_to_usbdev(intf);
+	struct snd_card *card;
+	int err;
+
+	if (id->driver_info & US122L_FLAG_US144 &&
+			device->speed == USB_SPEED_HIGH) {
+		dev_err(&device->dev, "disable ehci-hcd to run US-144\n");
+		return -ENODEV;
+	}
+
+	if (intf->cur_altsetting->desc.bInterfaceNumber != 1)
+		return 0;
+
+	err = us122l_usb_probe(intf, id, &card);
+	if (err < 0)
+		return err;
+
+	usb_set_intfdata(intf, card);
+	return 0;
+}
+
+static void snd_us122l_disconnect(struct usb_interface *intf)
+{
+	struct snd_card *card;
+	struct us122l *us122l;
+	struct list_head *p;
+
+	card = usb_get_intfdata(intf);
+	if (!card)
+		return;
+
+	snd_card_disconnect(card);
+
+	us122l = US122L(card);
+	scoped_guard(mutex, &us122l->mutex) {
+		us122l_stop(us122l);
+	}
+
+	/* release the midi resources */
+	list_for_each(p, &us122l->midi_list) {
+		snd_usbmidi_disconnect(p);
+	}
+
+	snd_card_free_when_closed(card);
+}
+
+static int snd_us122l_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct snd_card *card;
+	struct us122l *us122l;
+	struct list_head *p;
+
+	card = usb_get_intfdata(intf);
+	if (!card)
+		return 0;
+	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
+
+	us122l = US122L(card);
+	if (!us122l)
+		return 0;
+
+	list_for_each(p, &us122l->midi_list)
+		snd_usbmidi_input_stop(p);
+
+	guard(mutex)(&us122l->mutex);
+	usb_stream_stop(&us122l->sk);
+
+	return 0;
+}
+
+static int snd_us122l_resume(struct usb_interface *intf)
+{
+	struct snd_card *card;
+	struct us122l *us122l;
+	struct list_head *p;
+	int err;
+
+	card = usb_get_intfdata(intf);
+	if (!card)
+		return 0;
+
+	us122l = US122L(card);
+	if (!us122l)
+		return 0;
+
+	guard(mutex)(&us122l->mutex);
+	/* needed, doesn't restart without: */
+	if (us122l->is_us144) {
+		err = usb_set_interface(us122l->dev, 0, 1);
+		if (err) {
+			dev_err(&us122l->dev->dev, "usb_set_interface error\n");
+			goto unlock;
+		}
+	}
+	err = usb_set_interface(us122l->dev, 1, 1);
+	if (err) {
+		dev_err(&us122l->dev->dev, "usb_set_interface error\n");
+		goto unlock;
+	}
+
+	pt_info_set(us122l->dev, 0x11);
+	pt_info_set(us122l->dev, 0x10);
+
+	err = us122l_set_sample_rate(us122l->dev,
+				     us122l->sk.s->cfg.sample_rate);
+	if (err < 0) {
+		dev_err(&us122l->dev->dev, "us122l_set_sample_rate error\n");
+		goto unlock;
+	}
+	err = usb_stream_start(&us122l->sk);
+	if (err)
+		goto unlock;
+
+	list_for_each(p, &us122l->midi_list)
+		snd_usbmidi_input_start(p);
+unlock:
+	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
+	return err;
+}
+
+static const struct usb_device_id snd_us122l_usb_id_table[] = {
+	{
+		.match_flags =	USB_DEVICE_ID_MATCH_DEVICE,
+		.idVendor =	0x0644,
+		.idProduct =	USB_ID_US122L
+	},
+	{	/* US-144 only works at USB1.1! Disable module ehci-hcd. */
+		.match_flags =	USB_DEVICE_ID_MATCH_DEVICE,
+		.idVendor =	0x0644,
+		.idProduct =	USB_ID_US144,
+		.driver_info =	US122L_FLAG_US144
+	},
+	{
+		.match_flags =	USB_DEVICE_ID_MATCH_DEVICE,
+		.idVendor =	0x0644,
+		.idProduct =	USB_ID_US122MKII
+	},
+	{ /* terminator */ }
+};
+MODULE_DEVICE_TABLE(usb, snd_us122l_usb_id_table);
+
+static struct usb_driver snd_us122l_usb_driver = {
+	.name =		"snd-usb-us122l",
+	.probe =	snd_us122l_probe,
+	.disconnect =	snd_us122l_disconnect,
+	.suspend =	snd_us122l_suspend,
+	.resume =	snd_us122l_resume,
+	.reset_resume =	snd_us122l_resume,
+	.id_table =	snd_us122l_usb_id_table,
+	.supports_autosuspend = 1
+};
+
+module_usb_driver(snd_us122l_usb_driver);
diff --git a/sound/usb/usx2y/us122l.h b/sound/usb/usx2y/us122l.h
new file mode 100644
index 000000000..8e59b78d3
--- /dev/null
+++ b/sound/usb/usx2y/us122l.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef US122L_H
+#define US122L_H
+
+
+struct us122l {
+	struct usb_device	*dev;
+	int			card_index;
+	int			stride;
+	struct usb_stream_kernel sk;
+
+	struct mutex		mutex;
+	struct file		*first;
+	unsigned int		second_periods_polled;
+	struct file		*master;
+	struct file		*slave;
+	struct list_head	midi_list;
+
+	bool			is_us144;
+};
+
+
+#define US122L(c) ((struct us122l *)(c)->private_data)
+
+#define NAME_ALLCAPS "US-122L"
+
+#define USB_ID_US122L 0x800E
+#define USB_ID_US144 0x800F
+#define USB_ID_US122MKII 0x8021
+#define USB_ID_US144MKII 0x8020
+
+#endif
diff --git a/sound/usb/usx2y/us144mkii.c b/sound/usb/usx2y/us144mkii.c
new file mode 100644
index 000000000..58ef23146
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii.c
@@ -0,0 +1,629 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+/*
+ * ALSA Driver for TASCAM US-144MKII Audio Interface
+ */
+
+#include "us144mkii.h"
+
+MODULE_AUTHOR("Šerif Rami <ramiserifpersia@gmail.com>");
+MODULE_DESCRIPTION("ALSA Driver for TASCAM US-144MKII");
+MODULE_LICENSE("GPL");
+
+/*
+ * Module parameters for ALSA card instantiation.
+ *
+ * These parameters allow users to configure how the ALSA sound card
+ * for the TASCAM US-144MKII is instantiated.
+ *
+ * @param index: Array of integers specifying the ALSA card index for each
+ * device. Defaults to -1 (automatic).
+ * @param id: Array of strings specifying the ALSA card ID for each device.
+ *            Defaults to "US144MKII".
+ * @param enable: Array of booleans to enable or disable each device.
+ *                Defaults to {1, 0, ..., 0} (first device enabled).
+ * @param dev_idx: Internal counter for the number of TASCAM devices probed.
+ */
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;
+static bool enable[SNDRV_CARDS] = { 1, [1 ...(SNDRV_CARDS - 1)] = 0 };
+static int dev_idx;
+
+static int tascam_probe(struct usb_interface *intf,
+			const struct usb_device_id *usb_id);
+static void tascam_disconnect(struct usb_interface *intf);
+static int tascam_suspend(struct usb_interface *intf, pm_message_t message);
+static int tascam_resume(struct usb_interface *intf);
+
+void tascam_free_urbs(struct tascam_card *tascam)
+{
+	int i;
+
+	usb_kill_anchored_urbs(&tascam->playback_anchor);
+	for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
+		if (tascam->playback_urbs[i]) {
+			usb_free_coherent(
+				tascam->dev, tascam->playback_urb_alloc_size,
+				tascam->playback_urbs[i]->transfer_buffer,
+				tascam->playback_urbs[i]->transfer_dma);
+			usb_free_urb(tascam->playback_urbs[i]);
+			tascam->playback_urbs[i] = NULL;
+		}
+	}
+
+	usb_kill_anchored_urbs(&tascam->feedback_anchor);
+	for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
+		if (tascam->feedback_urbs[i]) {
+			usb_free_coherent(
+				tascam->dev, tascam->feedback_urb_alloc_size,
+				tascam->feedback_urbs[i]->transfer_buffer,
+				tascam->feedback_urbs[i]->transfer_dma);
+			usb_free_urb(tascam->feedback_urbs[i]);
+			tascam->feedback_urbs[i] = NULL;
+		}
+	}
+
+	usb_kill_anchored_urbs(&tascam->capture_anchor);
+	for (i = 0; i < NUM_CAPTURE_URBS; i++) {
+		if (tascam->capture_urbs[i]) {
+			usb_free_coherent(
+				tascam->dev, tascam->capture_urb_alloc_size,
+				tascam->capture_urbs[i]->transfer_buffer,
+				tascam->capture_urbs[i]->transfer_dma);
+			usb_free_urb(tascam->capture_urbs[i]);
+			tascam->capture_urbs[i] = NULL;
+		}
+	}
+
+	usb_kill_anchored_urbs(&tascam->midi_in_anchor);
+	for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
+		if (tascam->midi_in_urbs[i]) {
+			usb_free_coherent(
+				tascam->dev, MIDI_IN_BUF_SIZE,
+				tascam->midi_in_urbs[i]->transfer_buffer,
+				tascam->midi_in_urbs[i]->transfer_dma);
+			usb_free_urb(tascam->midi_in_urbs[i]);
+			tascam->midi_in_urbs[i] = NULL;
+		}
+	}
+
+	usb_kill_anchored_urbs(&tascam->midi_out_anchor);
+	for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
+		if (tascam->midi_out_urbs[i]) {
+			usb_free_coherent(
+				tascam->dev, MIDI_OUT_BUF_SIZE,
+				tascam->midi_out_urbs[i]->transfer_buffer,
+				tascam->midi_out_urbs[i]->transfer_dma);
+			usb_free_urb(tascam->midi_out_urbs[i]);
+			tascam->midi_out_urbs[i] = NULL;
+		}
+	}
+
+	kfree(tascam->capture_routing_buffer);
+	tascam->capture_routing_buffer = NULL;
+	kfree(tascam->capture_decode_dst_block);
+	tascam->capture_decode_dst_block = NULL;
+	kfree(tascam->capture_decode_raw_block);
+	tascam->capture_decode_raw_block = NULL;
+	kfree(tascam->capture_ring_buffer);
+	tascam->capture_ring_buffer = NULL;
+}
+
+int tascam_alloc_urbs(struct tascam_card *tascam)
+{
+	int i;
+	size_t max_packet_size;
+
+	max_packet_size = ((96000 / 8000) + 2) * BYTES_PER_FRAME;
+	tascam->playback_urb_alloc_size =
+		max_packet_size * PLAYBACK_URB_PACKETS;
+
+	for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
+		struct urb *urb =
+			usb_alloc_urb(PLAYBACK_URB_PACKETS, GFP_KERNEL);
+
+		if (!urb)
+			goto error;
+		tascam->playback_urbs[i] = urb;
+
+		urb->transfer_buffer = usb_alloc_coherent(
+			tascam->dev, tascam->playback_urb_alloc_size,
+			GFP_KERNEL, &urb->transfer_dma);
+		if (!urb->transfer_buffer)
+			goto error;
+
+		urb->dev = tascam->dev;
+		urb->pipe = usb_sndisocpipe(tascam->dev, EP_AUDIO_OUT);
+		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+		urb->interval = 1;
+		urb->context = tascam;
+		urb->complete = playback_urb_complete;
+	}
+
+	tascam->feedback_urb_alloc_size =
+		FEEDBACK_PACKET_SIZE * FEEDBACK_URB_PACKETS;
+
+	for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
+		struct urb *f_urb =
+			usb_alloc_urb(FEEDBACK_URB_PACKETS, GFP_KERNEL);
+
+		if (!f_urb)
+			goto error;
+		tascam->feedback_urbs[i] = f_urb;
+
+		f_urb->transfer_buffer = usb_alloc_coherent(
+			tascam->dev, tascam->feedback_urb_alloc_size,
+			GFP_KERNEL, &f_urb->transfer_dma);
+		if (!f_urb->transfer_buffer)
+			goto error;
+
+		f_urb->dev = tascam->dev;
+		f_urb->pipe =
+			usb_rcvisocpipe(tascam->dev, EP_PLAYBACK_FEEDBACK);
+		f_urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+		f_urb->interval = 4;
+		f_urb->context = tascam;
+		f_urb->complete = feedback_urb_complete;
+	}
+
+	tascam->capture_urb_alloc_size = CAPTURE_URB_SIZE;
+	for (i = 0; i < NUM_CAPTURE_URBS; i++) {
+		struct urb *c_urb = usb_alloc_urb(0, GFP_KERNEL);
+
+		if (!c_urb)
+			goto error;
+		tascam->capture_urbs[i] = c_urb;
+
+		c_urb->transfer_buffer = usb_alloc_coherent(
+			tascam->dev, tascam->capture_urb_alloc_size, GFP_KERNEL,
+			&c_urb->transfer_dma);
+		if (!c_urb->transfer_buffer)
+			goto error;
+
+		usb_fill_bulk_urb(c_urb, tascam->dev,
+				  usb_rcvbulkpipe(tascam->dev, EP_AUDIO_IN),
+				  c_urb->transfer_buffer,
+				  tascam->capture_urb_alloc_size,
+				  capture_urb_complete, tascam);
+		c_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	}
+
+	/* MIDI URB and buffer allocation */
+	for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
+		struct urb *m_urb = usb_alloc_urb(0, GFP_KERNEL);
+
+		if (!m_urb)
+			goto error;
+		tascam->midi_in_urbs[i] = m_urb;
+		m_urb->transfer_buffer =
+			usb_alloc_coherent(tascam->dev, MIDI_IN_BUF_SIZE,
+					   GFP_KERNEL, &m_urb->transfer_dma);
+		if (!m_urb->transfer_buffer)
+			goto error;
+		usb_fill_bulk_urb(m_urb, tascam->dev,
+				  usb_rcvbulkpipe(tascam->dev, EP_MIDI_IN),
+				  m_urb->transfer_buffer, MIDI_IN_BUF_SIZE,
+				  tascam_midi_in_urb_complete, tascam);
+		m_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	}
+
+	for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
+		struct urb *m_urb = usb_alloc_urb(0, GFP_KERNEL);
+
+		if (!m_urb)
+			goto error;
+		tascam->midi_out_urbs[i] = m_urb;
+		m_urb->transfer_buffer =
+			usb_alloc_coherent(tascam->dev, MIDI_OUT_BUF_SIZE,
+					   GFP_KERNEL, &m_urb->transfer_dma);
+		if (!m_urb->transfer_buffer)
+			goto error;
+		usb_fill_bulk_urb(m_urb, tascam->dev,
+				  usb_sndbulkpipe(tascam->dev, EP_MIDI_OUT),
+				  m_urb->transfer_buffer,
+				  0, /* length set later */
+				  tascam_midi_out_urb_complete, tascam);
+		m_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	}
+
+	tascam->capture_ring_buffer =
+		kmalloc(CAPTURE_RING_BUFFER_SIZE, GFP_KERNEL);
+	if (!tascam->capture_ring_buffer)
+		goto error;
+
+	tascam->capture_decode_raw_block =
+		kmalloc(RAW_BYTES_PER_DECODE_BLOCK, GFP_KERNEL);
+	if (!tascam->capture_decode_raw_block)
+		goto error;
+
+	tascam->capture_decode_dst_block =
+		kmalloc(FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
+				DECODED_SAMPLE_SIZE,
+			GFP_KERNEL);
+	if (!tascam->capture_decode_dst_block)
+		goto error;
+
+	tascam->capture_routing_buffer =
+		kmalloc(FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
+				DECODED_SAMPLE_SIZE,
+			GFP_KERNEL);
+	if (!tascam->capture_routing_buffer)
+		goto error;
+
+	return 0;
+
+error:
+	dev_err(tascam->card->dev, "Failed to allocate URBs\n");
+	tascam_free_urbs(tascam);
+	return -ENOMEM;
+}
+
+void tascam_stop_work_handler(struct work_struct *work)
+{
+	struct tascam_card *tascam =
+		container_of(work, struct tascam_card, stop_work);
+
+	usb_kill_anchored_urbs(&tascam->playback_anchor);
+	usb_kill_anchored_urbs(&tascam->feedback_anchor);
+	usb_kill_anchored_urbs(&tascam->capture_anchor);
+	atomic_set(&tascam->active_urbs, 0);
+}
+
+/*
+ * tascam_card_private_free() - Frees private data associated with the sound
+ * card.
+ * @card: Pointer to the ALSA sound card instance.
+ *
+ * This function is called when the sound card is being freed. It releases
+ * resources allocated for the tascam_card structure, including the MIDI
+ * input FIFO and decrements the USB device reference count.
+ */
+static void tascam_card_private_free(struct snd_card *card)
+{
+	struct tascam_card *tascam = card->private_data;
+
+	if (tascam) {
+		kfifo_free(&tascam->midi_in_fifo);
+		if (tascam->dev) {
+			usb_put_dev(tascam->dev);
+			tascam->dev = NULL;
+		}
+	}
+}
+
+/*
+ * tascam_suspend() - Handles device suspension.
+ * @intf: The USB interface being suspended.
+ * @message: Power management message.
+ *
+ * This function is called when the device is suspended. It stops all active
+ * streams, kills all URBs, and sends a vendor-specific deep sleep command
+ * to the device to ensure a stable low-power state.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct tascam_card *tascam = usb_get_intfdata(intf);
+
+	if (!tascam)
+		return 0;
+
+	snd_pcm_suspend_all(tascam->pcm);
+
+	cancel_work_sync(&tascam->stop_work);
+	cancel_work_sync(&tascam->capture_work);
+	cancel_work_sync(&tascam->midi_in_work);
+	cancel_work_sync(&tascam->midi_out_work);
+	cancel_work_sync(&tascam->stop_pcm_work);
+	usb_kill_anchored_urbs(&tascam->playback_anchor);
+	usb_kill_anchored_urbs(&tascam->capture_anchor);
+	usb_kill_anchored_urbs(&tascam->feedback_anchor);
+	usb_kill_anchored_urbs(&tascam->midi_in_anchor);
+	usb_kill_anchored_urbs(&tascam->midi_out_anchor);
+
+	dev_info(&intf->dev, "sending deep sleep command\n");
+	int err = usb_control_msg(tascam->dev, usb_sndctrlpipe(tascam->dev, 0),
+				  VENDOR_REQ_DEEP_SLEEP, RT_H2D_VENDOR_DEV,
+				  0x0000, 0x0000, NULL, 0, USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		dev_err(&intf->dev, "deep sleep command failed: %d\n", err);
+
+	return 0;
+}
+
+/*
+ * tascam_resume() - Handles device resumption from suspend.
+ * @intf: The USB interface being resumed.
+ *
+ * This function is called when the device resumes from suspend. It
+ * re-establishes the active USB interface settings and re-configures the sample
+ * rate if it was previously active.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int tascam_resume(struct usb_interface *intf)
+{
+	struct tascam_card *tascam = usb_get_intfdata(intf);
+	int err;
+
+	if (!tascam)
+		return 0;
+
+	dev_info(&intf->dev, "resuming TASCAM US-144MKII\n");
+
+	/*
+	 * The device requires a full re-initialization sequence upon resume.
+	 * First, re-establish the active USB interface settings.
+	 */
+	err = usb_set_interface(tascam->dev, 0, 1);
+	if (err < 0) {
+		dev_err(&intf->dev,
+			"resume: failed to set alt setting on intf 0: %d\n",
+			err);
+		return err;
+	}
+	err = usb_set_interface(tascam->dev, 1, 1);
+	if (err < 0) {
+		dev_err(&intf->dev,
+			"resume: failed to set alt setting on intf 1: %d\n",
+			err);
+		return err;
+	}
+
+	/* Re-configure the sample rate if one was previously active */
+	if (tascam->current_rate > 0)
+		us144mkii_configure_device_for_rate(tascam,
+						    tascam->current_rate);
+
+	return 0;
+}
+
+static void tascam_error_timer(struct timer_list *t)
+{
+	struct tascam_card *tascam =
+		container_of(t, struct tascam_card, error_timer);
+
+	if (atomic_read(&tascam->midi_in_active))
+		schedule_work(&tascam->midi_in_work);
+	if (atomic_read(&tascam->midi_out_active))
+		schedule_work(&tascam->midi_out_work);
+}
+
+/*
+ * tascam_probe() - Probes for the TASCAM US-144MKII device.
+ * @intf: The USB interface being probed.
+ * @usb_id: The USB device ID.
+ *
+ * This function is the entry point for the USB driver when a matching device
+ * is found. It performs initial device setup, including:
+ * - Checking for the second interface (MIDI) and associating it.
+ * - Performing a vendor-specific handshake with the device.
+ * - Setting alternate settings for USB interfaces.
+ * - Creating and registering the ALSA sound card, PCM device, and MIDI device.
+ * - Allocating and initializing URBs for audio and MIDI transfers.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int tascam_probe(struct usb_interface *intf,
+			const struct usb_device_id *usb_id)
+{
+	struct usb_device *dev = interface_to_usbdev(intf);
+	struct snd_card *card;
+	struct tascam_card *tascam;
+	int err;
+
+	if (dev->speed != USB_SPEED_HIGH)
+		dev_info(
+			&dev->dev,
+			"Device is connected to a USB 1.1 port, this is not supported.\n");
+
+	/* The device has two interfaces; we drive both from this driver. */
+	if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
+		struct usb_interface *intf_zero = usb_ifnum_to_if(dev, 0);
+
+		if (!intf_zero)
+			return -ENODEV;
+		tascam = usb_get_intfdata(intf_zero);
+		if (tascam) {
+			usb_set_intfdata(intf, tascam);
+			tascam->iface1 = intf;
+		}
+		return 0; /* Let the core handle this interface */
+	}
+
+	if (dev_idx >= SNDRV_CARDS) {
+		dev_err(&dev->dev, "Too many TASCAM devices present");
+		return -ENODEV;
+	}
+
+	if (!enable[dev_idx]) {
+		dev_info(&dev->dev, "TASCAM US-144MKII device disabled");
+		return -ENOENT;
+	}
+
+	char *handshake_buf __free(kfree) =
+		kmalloc(1, GFP_KERNEL);
+	if (!handshake_buf)
+		return -ENOMEM;
+
+	/* Perform vendor-specific handshake */
+	err = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
+			      VENDOR_REQ_MODE_CONTROL, RT_D2H_VENDOR_DEV,
+			      MODE_VAL_HANDSHAKE_READ, 0x0000, handshake_buf, 1,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0) {
+		dev_err(&dev->dev, "Handshake read failed with %d\n", err);
+		return err;
+	}
+
+	if (handshake_buf[0] != 0x12 && handshake_buf[0] != 0x16 &&
+	    handshake_buf[0] != 0x30 && handshake_buf[0] != 0x32) {
+		dev_err(&dev->dev, "Unexpected handshake value: 0x%x\n",
+			handshake_buf[0]);
+		return -ENODEV;
+	}
+
+	/* Set alternate settings to enable audio/MIDI endpoints */
+	err = usb_set_interface(dev, 0, 1);
+	if (err < 0) {
+		dev_err(&dev->dev,
+			"Failed to set alt setting 1 on interface 0: %d\n",
+			err);
+		return err;
+	}
+
+	err = usb_set_interface(dev, 1, 1);
+	if (err < 0) {
+		dev_err(&dev->dev,
+			"Failed to set alt setting 1 on interface 1: %d\n",
+			err);
+		return err;
+	}
+
+	err = snd_card_new(&dev->dev, index[dev_idx], id[dev_idx], THIS_MODULE,
+			   sizeof(struct tascam_card), &card);
+	if (err < 0) {
+		dev_err(&dev->dev, "Failed to create sound card instance\n");
+		return err;
+	}
+
+	tascam = card->private_data;
+	card->private_free = tascam_card_private_free;
+	tascam->dev = usb_get_dev(dev);
+	tascam->card = card;
+	tascam->iface0 = intf;
+	tascam->digital_out_source = 1;
+	tascam->capture_34_source = 1;
+
+	spin_lock_init(&tascam->lock);
+	spin_lock_init(&tascam->midi_in_lock);
+	spin_lock_init(&tascam->midi_out_lock);
+	init_usb_anchor(&tascam->playback_anchor);
+	init_usb_anchor(&tascam->capture_anchor);
+	init_usb_anchor(&tascam->feedback_anchor);
+	init_usb_anchor(&tascam->midi_in_anchor);
+	init_usb_anchor(&tascam->midi_out_anchor);
+
+	timer_setup(&tascam->error_timer, tascam_error_timer, 0);
+
+	INIT_WORK(&tascam->stop_work, tascam_stop_work_handler);
+	INIT_WORK(&tascam->stop_pcm_work, tascam_stop_pcm_work_handler);
+	INIT_WORK(&tascam->capture_work, tascam_capture_work_handler);
+	init_completion(&tascam->midi_out_drain_completion);
+
+	if (kfifo_alloc(&tascam->midi_in_fifo, MIDI_IN_FIFO_SIZE, GFP_KERNEL)) {
+		snd_card_free(card);
+		return -ENOMEM;
+	}
+
+	strscpy(card->driver, DRIVER_NAME, sizeof(card->driver));
+	if (le16_to_cpu(dev->descriptor.idProduct) == USB_PID_TASCAM_US144) {
+		strscpy(card->shortname, "TASCAM US-144",
+			sizeof(card->shortname));
+	} else if (le16_to_cpu(dev->descriptor.idProduct) == USB_PID_TASCAM_US144MKII) {
+		strscpy(card->shortname, "TASCAM US-144MKII",
+			sizeof(card->shortname));
+	} else {
+		strscpy(card->shortname, "TASCAM Unknown",
+			sizeof(card->shortname));
+	}
+	snprintf(card->longname, sizeof(card->longname), "%s (%04x:%04x) at %s",
+		 card->shortname, USB_VID_TASCAM, dev->descriptor.idProduct,
+		 dev_name(&dev->dev));
+
+	err = snd_pcm_new(card, "US144MKII PCM", 0, 1, 1, &tascam->pcm);
+	if (err < 0)
+		goto free_card;
+	tascam->pcm->private_data = tascam;
+	strscpy(tascam->pcm->name, "US144MKII PCM", sizeof(tascam->pcm->name));
+
+	err = tascam_init_pcm(tascam->pcm);
+	if (err < 0)
+		goto free_card;
+
+	err = tascam_create_midi(tascam);
+	if (err < 0)
+		goto free_card;
+
+	err = tascam_create_controls(tascam);
+	if (err < 0)
+		goto free_card;
+
+	err = tascam_alloc_urbs(tascam);
+	if (err < 0)
+		goto free_card;
+
+	err = snd_card_register(card);
+	if (err < 0)
+		goto free_card;
+
+	usb_set_intfdata(intf, tascam);
+
+	dev_idx++;
+	return 0;
+
+free_card:
+	tascam_free_urbs(tascam);
+	snd_card_free(card);
+	return err;
+}
+
+/*
+ * tascam_disconnect() - Disconnects the TASCAM US-144MKII device.
+ * @intf: The USB interface being disconnected.
+ *
+ * This function is called when the device is disconnected from the system.
+ * It cleans up all allocated resources, including killing URBs, freeing
+ * the sound card, and releasing memory.
+ */
+static void tascam_disconnect(struct usb_interface *intf)
+{
+	struct tascam_card *tascam = usb_get_intfdata(intf);
+
+	if (!tascam)
+		return;
+
+	if (intf->cur_altsetting->desc.bInterfaceNumber == 0) {
+		snd_card_disconnect(tascam->card);
+
+		/*
+		 * Kill the URBs before cancelling the work, so a late URB
+		 * completion cannot re-arm a work that then runs after
+		 * snd_card_free().
+		 */
+		usb_kill_anchored_urbs(&tascam->playback_anchor);
+		usb_kill_anchored_urbs(&tascam->capture_anchor);
+		usb_kill_anchored_urbs(&tascam->feedback_anchor);
+		usb_kill_anchored_urbs(&tascam->midi_in_anchor);
+		usb_kill_anchored_urbs(&tascam->midi_out_anchor);
+
+		cancel_work_sync(&tascam->stop_work);
+		cancel_work_sync(&tascam->capture_work);
+		cancel_work_sync(&tascam->midi_in_work);
+		cancel_work_sync(&tascam->midi_out_work);
+		cancel_work_sync(&tascam->stop_pcm_work);
+		timer_delete_sync(&tascam->error_timer);
+		tascam_free_urbs(tascam);
+		snd_card_free(tascam->card);
+		dev_idx--;
+	}
+}
+
+static const struct usb_device_id tascam_usb_ids[] = {
+	{ USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144) },
+	{ USB_DEVICE(USB_VID_TASCAM, USB_PID_TASCAM_US144MKII) },
+	{ /* Terminating entry */ }
+};
+MODULE_DEVICE_TABLE(usb, tascam_usb_ids);
+
+static struct usb_driver tascam_alsa_driver = {
+	.name = DRIVER_NAME,
+	.probe = tascam_probe,
+	.disconnect = tascam_disconnect,
+	.suspend = tascam_suspend,
+	.resume = tascam_resume,
+	.id_table = tascam_usb_ids,
+};
+
+module_usb_driver(tascam_alsa_driver);
diff --git a/sound/usb/usx2y/us144mkii.h b/sound/usb/usx2y/us144mkii.h
new file mode 100644
index 000000000..95c4341f0
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii.h
@@ -0,0 +1,367 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#ifndef __US144MKII_H
+#define __US144MKII_H
+
+#include <linux/kfifo.h>
+#include <linux/timer.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
+#include <sound/control.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/rawmidi.h>
+
+#define DRIVER_NAME "us144mkii"
+
+/* --- USB Device Identification --- */
+#define USB_VID_TASCAM 0x0644
+#define USB_PID_TASCAM_US144 0x800f
+#define USB_PID_TASCAM_US144MKII 0x8020
+
+/* --- USB Endpoints (Alternate Setting 1) --- */
+#define EP_PLAYBACK_FEEDBACK 0x81
+#define EP_AUDIO_OUT 0x02
+#define EP_MIDI_IN 0x83
+#define EP_MIDI_OUT 0x04
+#define EP_AUDIO_IN 0x86
+
+/* --- USB Control Message Protocol --- */
+#define RT_H2D_CLASS_EP (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT)
+#define RT_D2H_CLASS_EP (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT)
+#define RT_H2D_VENDOR_DEV (USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
+#define RT_D2H_VENDOR_DEV (USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE)
+
+enum uac_request {
+	UAC_SET_CUR = 0x01,
+	UAC_GET_CUR = 0x81,
+};
+
+enum uac_control_selector {
+	UAC_SAMPLING_FREQ_CONTROL = 0x0100,
+};
+
+enum tascam_vendor_request {
+	VENDOR_REQ_REGISTER_WRITE = 0x41,
+	VENDOR_REQ_DEEP_SLEEP = 0x44,
+	VENDOR_REQ_MODE_CONTROL = 0x49,
+};
+
+enum tascam_mode_value {
+	MODE_VAL_HANDSHAKE_READ = 0x0000,
+	MODE_VAL_CONFIG = 0x0010,
+	MODE_VAL_STREAM_START = 0x0030,
+};
+
+#define HANDSHAKE_SUCCESS_VAL 0x12
+
+enum tascam_register {
+	REG_ADDR_UNKNOWN_0D = 0x0d04,
+	REG_ADDR_UNKNOWN_0E = 0x0e00,
+	REG_ADDR_UNKNOWN_0F = 0x0f00,
+	REG_ADDR_RATE_44100 = 0x1000,
+	REG_ADDR_RATE_48000 = 0x1002,
+	REG_ADDR_RATE_88200 = 0x1008,
+	REG_ADDR_RATE_96000 = 0x100a,
+	REG_ADDR_UNKNOWN_11 = 0x110b,
+};
+
+#define REG_VAL_ENABLE 0x0101
+
+/* --- URB Configuration --- */
+#define NUM_PLAYBACK_URBS 4
+#define PLAYBACK_URB_PACKETS 8
+#define NUM_FEEDBACK_URBS 4
+#define FEEDBACK_URB_PACKETS 1
+#define FEEDBACK_PACKET_SIZE 3
+#define NUM_CAPTURE_URBS 8
+#define CAPTURE_URB_SIZE 512
+#define CAPTURE_RING_BUFFER_SIZE (CAPTURE_URB_SIZE * NUM_CAPTURE_URBS * 4)
+#define NUM_MIDI_IN_URBS 4
+#define MIDI_IN_BUF_SIZE 64
+#define MIDI_IN_FIFO_SIZE (MIDI_IN_BUF_SIZE * NUM_MIDI_IN_URBS)
+#define MIDI_OUT_BUF_SIZE 64
+#define NUM_MIDI_OUT_URBS 4
+#define USB_CTRL_TIMEOUT_MS 1000
+#define FEEDBACK_SYNC_LOSS_THRESHOLD 41
+
+/* --- Audio Format Configuration --- */
+#define BYTES_PER_SAMPLE 3
+#define NUM_CHANNELS 4
+#define BYTES_PER_FRAME (NUM_CHANNELS * BYTES_PER_SAMPLE)
+#define FEEDBACK_ACCUMULATOR_SIZE 128
+
+/* --- Capture Decoding Defines --- */
+#define DECODED_CHANNELS_PER_FRAME 4
+#define DECODED_SAMPLE_SIZE 4
+#define FRAMES_PER_DECODE_BLOCK 8
+#define RAW_BYTES_PER_DECODE_BLOCK 512
+
+/**
+ * struct us144mkii_frame_pattern_observer - State for dynamic feedback
+ * patterns.
+ * @sample_rate_khz: The current sample rate in kHz.
+ * @base_feedback_value: The nominal feedback value for the current rate.
+ * @feedback_offset: An offset to align the feedback value range.
+ * @full_frame_patterns: A 2D array of pre-calculated packet size patterns.
+ * @current_index: The current index into the pattern array.
+ * @previous_index: The previous index, used for state tracking.
+ * @sync_locked: A flag indicating if the pattern has locked to the stream.
+ */
+struct us144mkii_frame_pattern_observer {
+	unsigned int sample_rate_khz;
+	unsigned int base_feedback_value;
+	int feedback_offset;
+	unsigned int full_frame_patterns[5][8];
+	unsigned int current_index;
+	unsigned int previous_index;
+	bool sync_locked;
+};
+
+/**
+ * struct tascam_card - Main driver data structure for the TASCAM US-144MKII.
+ * @dev: Pointer to the USB device.
+ * @iface0: Pointer to USB interface 0 (audio).
+ * @iface1: Pointer to USB interface 1 (MIDI).
+ * @card: Pointer to the ALSA sound card instance.
+ * @pcm: Pointer to the ALSA PCM device.
+ * @rmidi: Pointer to the ALSA rawmidi device.
+ *
+ * @playback_substream: Pointer to the active playback PCM substream.
+ * @playback_urbs: Array of URBs for playback.
+ * @playback_urb_alloc_size: Size of allocated buffer for each playback URB.
+ * @feedback_urbs: Array of URBs for feedback.
+ * @feedback_urb_alloc_size: Size of allocated buffer for each feedback URB.
+ * @playback_active: Atomic flag indicating if playback is active.
+ * @playback_frames_consumed: Total frames consumed by playback.
+ * @driver_playback_pos: Current position in the ALSA playback buffer (frames).
+ * @last_period_pos: Last reported period position for playback.
+ *
+ * @capture_substream: Pointer to the active capture PCM substream.
+ * @capture_urbs: Array of URBs for capture.
+ * @capture_urb_alloc_size: Size of allocated buffer for each capture URB.
+ * @capture_active: Atomic flag indicating if capture is active.
+ * @driver_capture_pos: Current position in the ALSA capture buffer (frames).
+ * @capture_frames_processed: Total frames processed for capture.
+ * @last_capture_period_pos: Last reported period position for capture.
+ * @capture_ring_buffer: Ring buffer for raw capture data from USB.
+ * @capture_ring_buffer_read_ptr: Read pointer for the capture ring buffer.
+ * @capture_ring_buffer_write_ptr: Write pointer for the capture ring buffer.
+ * @capture_decode_raw_block: Buffer for a raw 512-byte capture block.
+ * @capture_decode_dst_block: Buffer for decoded 32-bit capture samples.
+ * @capture_routing_buffer: Intermediate buffer for capture routing.
+ * @capture_work: Work struct for deferred capture processing.
+ * @stop_work: Work struct for deferred stream stopping.
+ * @stop_pcm_work: Work struct for stopping PCM due to a fatal error (e.g.
+ * xrun).
+ *
+ * @midi_in_substream: Pointer to the active MIDI input substream.
+ * @midi_out_substream: Pointer to the active MIDI output substream.
+ * @midi_in_urbs: Array of URBs for MIDI input.
+ * @midi_out_urbs: Array of URBs for MIDI output.
+ * @midi_in_active: Atomic flag indicating if MIDI input is active.
+ * @midi_out_active: Atomic flag indicating if MIDI output is active.
+ * @midi_in_fifo: FIFO for raw MIDI input data.
+ * @midi_in_work: Work struct for deferred MIDI input processing.
+ * @midi_out_work: Work struct for deferred MIDI output processing.
+ * @midi_in_lock: Spinlock for MIDI input FIFO.
+ * @midi_out_lock: Spinlock for MIDI output.
+ * @midi_out_urbs_in_flight: Bitmap of MIDI output URBs currently in flight.
+ * @midi_running_status: Stores the last MIDI status byte for running status.
+ * @error_timer: Timer for MIDI error retry logic.
+ *
+ * @lock: Main spinlock for protecting shared driver state.
+ * @active_urbs: Atomic counter for active URBs.
+ * @current_rate: Currently configured sample rate of the device.
+ * @line_out_source: Source for Line Outputs (0: Playback 1-2, 1: Playback 3-4).
+ * @digital_out_source: Source for Digital Outputs (0: Playback 1-2, 1: Playback
+ * 3-4).
+ * @capture_12_source: Source for Capture channels 1-2 (0: Analog In, 1: Digital
+ * In).
+ * @capture_34_source: Source for Capture channels 3-4 (0: Analog In, 1: Digital
+ * In).
+ *
+ * @feedback_accumulator_pattern: Stores the calculated frames per packet for
+ * feedback.
+ * @feedback_pattern_out_idx: Read index for feedback_accumulator_pattern.
+ * @feedback_pattern_in_idx: Write index for feedback_accumulator_pattern.
+ * @feedback_synced: Flag indicating if feedback is synced.
+ * @feedback_consecutive_errors: Counter for consecutive feedback errors.
+ * @feedback_urb_skip_count: Number of feedback URBs to skip initially for
+ * stabilization.
+ * @fpo: Holds the state for the dynamic feedback pattern generation.
+ *
+ * @playback_anchor: USB anchor for playback URBs.
+ * @capture_anchor: USB anchor for capture URBs.
+ * @feedback_anchor: USB anchor for feedback URBs.
+ * @midi_in_anchor: USB anchor for MIDI input URBs.
+ * @midi_out_anchor: USB anchor for MIDI output URBs.
+ */
+struct tascam_card {
+	/* --- Core device pointers --- */
+	struct usb_device *dev;
+	struct usb_interface *iface0;
+	struct usb_interface *iface1;
+	struct snd_card *card;
+	struct snd_pcm *pcm;
+	struct snd_rawmidi *rmidi;
+
+	/* --- PCM Substreams --- */
+	struct snd_pcm_substream *playback_substream;
+	struct snd_pcm_substream *capture_substream;
+
+	/* --- URBs and Anchors --- */
+	struct urb *playback_urbs[NUM_PLAYBACK_URBS];
+	size_t playback_urb_alloc_size;
+	struct urb *feedback_urbs[NUM_FEEDBACK_URBS];
+	size_t feedback_urb_alloc_size;
+	struct urb *capture_urbs[NUM_CAPTURE_URBS];
+	size_t capture_urb_alloc_size;
+	struct urb *midi_in_urbs[NUM_MIDI_IN_URBS];
+	struct urb *midi_out_urbs[NUM_MIDI_OUT_URBS];
+	struct usb_anchor playback_anchor;
+	struct usb_anchor capture_anchor;
+	struct usb_anchor feedback_anchor;
+	struct usb_anchor midi_in_anchor;
+	struct usb_anchor midi_out_anchor;
+
+	/* --- Stream State --- */
+	spinlock_t lock;
+	atomic_t playback_active;
+	atomic_t capture_active;
+	atomic_t active_urbs;
+	int current_rate;
+
+	/* --- Playback State --- */
+	u64 playback_frames_consumed;
+	snd_pcm_uframes_t driver_playback_pos;
+	u64 last_period_pos;
+
+	/* --- Capture State --- */
+	u64 capture_frames_processed;
+	snd_pcm_uframes_t driver_capture_pos;
+	u64 last_capture_period_pos;
+	u8 *capture_ring_buffer;
+	size_t capture_ring_buffer_read_ptr;
+	size_t capture_ring_buffer_write_ptr;
+	u8 *capture_decode_raw_block;
+	s32 *capture_decode_dst_block;
+	s32 *capture_routing_buffer;
+
+	/* --- MIDI State --- */
+	struct snd_rawmidi_substream *midi_in_substream;
+	struct snd_rawmidi_substream *midi_out_substream;
+	atomic_t midi_in_active;
+	atomic_t midi_out_active;
+	struct kfifo midi_in_fifo;
+	spinlock_t midi_in_lock;
+	spinlock_t midi_out_lock;
+	unsigned long midi_out_urbs_in_flight;
+	u8 midi_running_status;
+	struct timer_list error_timer;
+	struct completion midi_out_drain_completion;
+
+	/* --- Feedback Sync State --- */
+	unsigned int feedback_accumulator_pattern[FEEDBACK_ACCUMULATOR_SIZE];
+	unsigned int feedback_pattern_out_idx;
+	unsigned int feedback_pattern_in_idx;
+	bool feedback_synced;
+	unsigned int feedback_consecutive_errors;
+	unsigned int feedback_urb_skip_count;
+	struct us144mkii_frame_pattern_observer fpo;
+
+	/* --- Workqueues --- */
+	struct work_struct stop_work;
+	struct work_struct stop_pcm_work;
+	struct work_struct capture_work;
+	struct work_struct midi_in_work;
+	struct work_struct midi_out_work;
+
+	/* --- Mixer/Routing State --- */
+	unsigned int line_out_source;
+	unsigned int digital_out_source;
+	unsigned int capture_12_source;
+	unsigned int capture_34_source;
+};
+
+/* main.c */
+/**
+ * tascam_free_urbs() - Free all allocated URBs and associated buffers.
+ * @tascam: the tascam_card instance
+ *
+ * This function kills, unlinks, and frees all playback, feedback, capture,
+ * and MIDI URBs, along with their transfer buffers and the capture
+ * ring/decode buffers.
+ */
+void tascam_free_urbs(struct tascam_card *tascam);
+
+/**
+ * tascam_alloc_urbs() - Allocate all URBs and associated buffers.
+ * @tascam: the tascam_card instance
+ *
+ * This function allocates and initializes all URBs for playback, feedback,
+ * capture, and MIDI, as well as the necessary buffers for data processing.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int tascam_alloc_urbs(struct tascam_card *tascam);
+
+/**
+ * tascam_stop_work_handler() - Work handler to stop all active streams.
+ * @work: Pointer to the work_struct.
+ *
+ * This function is scheduled to stop all active URBs (playback, feedback,
+ * capture) and reset the active_urbs counter.
+ */
+void tascam_stop_work_handler(struct work_struct *work);
+
+/* us144mkii_pcm.h */
+#include "us144mkii_pcm.h"
+
+/* us144mkii_midi.c */
+/**
+ * tascam_midi_in_urb_complete() - Completion handler for MIDI IN URBs
+ * @urb: The completed URB.
+ *
+ * This function runs in interrupt context. It places the raw data from the
+ * USB endpoint into a kfifo and schedules a work item to process it later,
+ * ensuring the interrupt handler remains fast.
+ */
+void tascam_midi_in_urb_complete(struct urb *urb);
+
+/**
+ * tascam_midi_out_urb_complete() - Completion handler for MIDI OUT bulk URB.
+ * @urb: The completed URB.
+ *
+ * This function runs in interrupt context. It marks the output URB as no
+ * longer in-flight. It then re-schedules the work handler to check for and
+ * send any more data waiting in the ALSA buffer. This is a safe, non-blocking
+ * way to continue the data transmission chain.
+ */
+void tascam_midi_out_urb_complete(struct urb *urb);
+
+/**
+ * tascam_create_midi() - Create and initialize the ALSA rawmidi device.
+ * @tascam: The driver instance.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int tascam_create_midi(struct tascam_card *tascam);
+
+/* us144mkii_controls.c */
+/**
+ * tascam_create_controls() - Creates and adds ALSA mixer controls for the
+ * device.
+ * @tascam: The driver instance.
+ *
+ * This function registers custom ALSA controls for managing audio routing
+ * (line out source, digital out source, capture 1-2 source, capture 3-4 source)
+ * and displaying the current sample rate.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int tascam_create_controls(struct tascam_card *tascam);
+
+#endif /* __US144MKII_H */
diff --git a/sound/usb/usx2y/us144mkii_capture.c b/sound/usb/usx2y/us144mkii_capture.c
new file mode 100644
index 000000000..d7cdf9e0f
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii_capture.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#include "us144mkii.h"
+
+/*
+ * tascam_capture_open() - Opens the PCM capture substream.
+ * @substream: The ALSA PCM substream to open.
+ *
+ * This function sets the hardware parameters for the capture substream
+ * and stores a reference to the substream in the driver's private data.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_capture_open(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+
+	substream->runtime->hw = tascam_pcm_hw;
+	tascam->capture_substream = substream;
+	atomic_set(&tascam->capture_active, 0);
+
+	return 0;
+}
+
+/*
+ * tascam_capture_close() - Closes the PCM capture substream.
+ * @substream: The ALSA PCM substream to close.
+ *
+ * This function clears the reference to the capture substream in the
+ * driver's private data.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_capture_close(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+
+	tascam->capture_substream = NULL;
+
+	return 0;
+}
+
+/*
+ * tascam_capture_prepare() - Prepares the PCM capture substream for use.
+ * @substream: The ALSA PCM substream to prepare.
+ *
+ * This function initializes capture-related counters and ring buffer pointers.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_capture_prepare(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+
+	tascam->driver_capture_pos = 0;
+	tascam->capture_frames_processed = 0;
+	tascam->last_capture_period_pos = 0;
+	tascam->capture_ring_buffer_read_ptr = 0;
+	tascam->capture_ring_buffer_write_ptr = 0;
+
+	return 0;
+}
+
+/*
+ * tascam_capture_pointer() - Returns the current capture pointer position.
+ * @substream: The ALSA PCM substream.
+ *
+ * This function returns the current position of the capture pointer within
+ * the ALSA ring buffer, in frames.
+ *
+ * Return: The current capture pointer position in frames.
+ */
+static snd_pcm_uframes_t
+tascam_capture_pointer(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	u64 pos;
+
+	if (!atomic_read(&tascam->capture_active))
+		return 0;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		pos = tascam->capture_frames_processed;
+	}
+
+	if (runtime->buffer_size == 0)
+		return 0;
+
+	return do_div(pos, runtime->buffer_size);
+}
+
+/*
+ * tascam_capture_ops - ALSA PCM operations for capture.
+ *
+ * This structure defines the callback functions for capture stream operations,
+ * including open, close, ioctl, hardware parameters, hardware free, prepare,
+ * trigger, and pointer.
+ */
+const struct snd_pcm_ops tascam_capture_ops = {
+	.open = tascam_capture_open,
+	.close = tascam_capture_close,
+	.ioctl = snd_pcm_lib_ioctl,
+	.hw_params = tascam_pcm_hw_params,
+	.hw_free = tascam_pcm_hw_free,
+	.prepare = tascam_capture_prepare,
+	.trigger = tascam_pcm_trigger,
+	.pointer = tascam_capture_pointer,
+};
+
+/*
+ * decode_tascam_capture_block() - Decodes a raw 512-byte block from the device.
+ * @src_block: Pointer to the 512-byte raw source block.
+ * @dst_block: Pointer to the destination buffer for decoded audio frames.
+ *
+ * The device sends audio data in a complex, multiplexed format. This function
+ * demultiplexes the bits from the raw block into 8 frames of 4-channel,
+ * 24-bit audio (stored in 32-bit containers).
+ */
+static void decode_tascam_capture_block(const u8 *src_block, s32 *dst_block)
+{
+	int frame, bit;
+
+	memset(dst_block, 0,
+	       FRAMES_PER_DECODE_BLOCK * DECODED_CHANNELS_PER_FRAME *
+		       DECODED_SAMPLE_SIZE);
+
+	for (frame = 0; frame < FRAMES_PER_DECODE_BLOCK; ++frame) {
+		const u8 *p_src_frame_base = src_block + frame * 64;
+		s32 *p_dst_frame = dst_block + frame * 4;
+
+		s32 ch[4] = { 0 };
+
+		for (bit = 0; bit < 24; ++bit) {
+			u8 byte1 = p_src_frame_base[bit];
+			u8 byte2 = p_src_frame_base[bit + 32];
+
+			ch[0] = (ch[0] << 1) | (byte1 & 1);
+			ch[2] = (ch[2] << 1) | ((byte1 >> 1) & 1);
+
+			ch[1] = (ch[1] << 1) | (byte2 & 1);
+			ch[3] = (ch[3] << 1) | ((byte2 >> 1) & 1);
+		}
+
+		/*
+		 * The result is a 24-bit sample. Shift left by 8 to align it to
+		 * the most significant bits of a 32-bit integer (S32_LE format).
+		 */
+		p_dst_frame[0] = ch[0] << 8;
+		p_dst_frame[1] = ch[1] << 8;
+		p_dst_frame[2] = ch[2] << 8;
+		p_dst_frame[3] = ch[3] << 8;
+	}
+}
+
+void tascam_capture_work_handler(struct work_struct *work)
+{
+	struct tascam_card *tascam =
+		container_of(work, struct tascam_card, capture_work);
+	struct snd_pcm_substream *substream = tascam->capture_substream;
+	struct snd_pcm_runtime *runtime;
+	u8 *raw_block = tascam->capture_decode_raw_block;
+	s32 *decoded_block = tascam->capture_decode_dst_block;
+	s32 *routed_block = tascam->capture_routing_buffer;
+
+	if (!substream || !substream->runtime)
+		return;
+	runtime = substream->runtime;
+
+	if (!raw_block || !decoded_block || !routed_block) {
+		dev_err(tascam->card->dev,
+			"Capture decode/routing buffers not allocated!\n");
+		return;
+	}
+
+	while (atomic_read(&tascam->capture_active)) {
+		size_t write_ptr, read_ptr, available_data;
+		bool can_process;
+
+		scoped_guard(spinlock_irqsave, &tascam->lock) {
+			write_ptr = tascam->capture_ring_buffer_write_ptr;
+			read_ptr = tascam->capture_ring_buffer_read_ptr;
+			available_data = (write_ptr >= read_ptr) ?
+						 (write_ptr - read_ptr) :
+						 (CAPTURE_RING_BUFFER_SIZE -
+						  read_ptr + write_ptr);
+			can_process =
+				(available_data >= RAW_BYTES_PER_DECODE_BLOCK);
+
+			if (can_process) {
+				size_t bytes_to_end =
+					CAPTURE_RING_BUFFER_SIZE - read_ptr;
+				if (bytes_to_end >=
+				    RAW_BYTES_PER_DECODE_BLOCK) {
+					memcpy(raw_block,
+					       tascam->capture_ring_buffer +
+						       read_ptr,
+					       RAW_BYTES_PER_DECODE_BLOCK);
+				} else {
+					memcpy(raw_block,
+					       tascam->capture_ring_buffer +
+						       read_ptr,
+					       bytes_to_end);
+					memcpy(raw_block + bytes_to_end,
+					       tascam->capture_ring_buffer,
+					       RAW_BYTES_PER_DECODE_BLOCK -
+						       bytes_to_end);
+				}
+				tascam->capture_ring_buffer_read_ptr =
+					(read_ptr +
+					 RAW_BYTES_PER_DECODE_BLOCK) %
+					CAPTURE_RING_BUFFER_SIZE;
+			}
+		}
+
+		if (!can_process)
+			break;
+
+		decode_tascam_capture_block(raw_block, decoded_block);
+		process_capture_routing_us144mkii(tascam, decoded_block,
+						  routed_block);
+
+		scoped_guard(spinlock_irqsave, &tascam->lock) {
+			if (atomic_read(&tascam->capture_active)) {
+				int f;
+
+				for (f = 0; f < FRAMES_PER_DECODE_BLOCK; ++f) {
+					u8 *dst_frame_start =
+						runtime->dma_area +
+						frames_to_bytes(
+							runtime,
+							tascam->driver_capture_pos);
+					s32 *routed_frame_start =
+						routed_block +
+						(f * NUM_CHANNELS);
+					int c;
+
+					for (c = 0; c < NUM_CHANNELS; c++) {
+						u8 *dst_channel =
+							dst_frame_start +
+							(c * BYTES_PER_SAMPLE);
+						s32 *src_channel_s32 =
+							routed_frame_start + c;
+
+						memcpy(dst_channel,
+						       ((char *)src_channel_s32) +
+							       1,
+						       3);
+					}
+
+					tascam->driver_capture_pos =
+						(tascam->driver_capture_pos +
+						 1) %
+						runtime->buffer_size;
+				}
+			}
+		}
+	}
+}
+
+void capture_urb_complete(struct urb *urb)
+{
+	struct tascam_card *tascam = urb->context;
+	int ret;
+
+	if (urb->status) {
+		if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
+		    urb->status != -ESHUTDOWN && urb->status != -ENODEV &&
+		    urb->status != -EPROTO)
+			dev_err_ratelimited(tascam->card->dev,
+					    "Capture URB failed: %d\n",
+					    urb->status);
+		goto out;
+	}
+	if (!tascam || !atomic_read(&tascam->capture_active))
+		goto out;
+
+	if (urb->actual_length > 0) {
+		scoped_guard(spinlock_irqsave, &tascam->lock) {
+			size_t write_ptr = tascam->capture_ring_buffer_write_ptr;
+			size_t bytes_to_end = CAPTURE_RING_BUFFER_SIZE - write_ptr;
+
+			if (urb->actual_length > bytes_to_end) {
+				memcpy(tascam->capture_ring_buffer + write_ptr,
+				       urb->transfer_buffer, bytes_to_end);
+				memcpy(tascam->capture_ring_buffer,
+				       urb->transfer_buffer + bytes_to_end,
+				       urb->actual_length - bytes_to_end);
+			} else {
+				memcpy(tascam->capture_ring_buffer + write_ptr,
+				       urb->transfer_buffer,
+				       urb->actual_length);
+			}
+
+			tascam->capture_ring_buffer_write_ptr =
+				(write_ptr + urb->actual_length) %
+				CAPTURE_RING_BUFFER_SIZE;
+		}
+
+		schedule_work(&tascam->capture_work);
+	}
+
+	usb_get_urb(urb);
+	usb_anchor_urb(urb, &tascam->capture_anchor);
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret < 0) {
+		dev_err_ratelimited(tascam->card->dev,
+				    "Failed to resubmit capture URB: %d\n",
+				    ret);
+		usb_unanchor_urb(urb);
+		usb_put_urb(urb);
+		atomic_dec(
+			&tascam->active_urbs); /* Decrement on failed resubmission */
+		return;
+	}
+out:
+	usb_put_urb(urb);
+}
+
diff --git a/sound/usb/usx2y/us144mkii_controls.c b/sound/usb/usx2y/us144mkii_controls.c
new file mode 100644
index 000000000..81ded11e3
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii_controls.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#include "us144mkii.h"
+
+/*
+ * Text descriptions for playback output source options.
+ *
+ * Used by ALSA kcontrol elements to provide user-friendly names for
+ * the playback routing options (e.g., "Playback 1-2", "Playback 3-4").
+ */
+static const char *const playback_source_texts[] = { "Playback 1-2",
+						     "Playback 3-4" };
+
+/*
+ * Text descriptions for capture input source options.
+ *
+ * Used by ALSA kcontrol elements to provide user-friendly names for
+ * the capture routing options (e.g., "Analog In", "Digital In").
+ */
+static const char *const capture_source_texts[] = { "Analog In", "Digital In" };
+
+/*
+ * tascam_playback_source_info() - ALSA control info callback for playback
+ * source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @uinfo: The ALSA control element info structure to fill.
+ *
+ * This function provides information about the enumerated playback source
+ * control, including its type, count, and available items (Playback 1-2,
+ * Playback 3-4).
+ *
+ * Return: 0 on success.
+ */
+static int tascam_playback_source_info(struct snd_kcontrol *kcontrol,
+				       struct snd_ctl_elem_info *uinfo)
+{
+	return snd_ctl_enum_info(uinfo, 1, 2, playback_source_texts);
+}
+
+/*
+ * tascam_line_out_get() - ALSA control get callback for Line Outputs Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure to fill.
+ *
+ * This function retrieves the current selection for the Line Outputs source
+ * (Playback 1-2 or Playback 3-4) from the driver's private data and populates
+ * the ALSA control element value.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_line_out_get(struct snd_kcontrol *kcontrol,
+			       struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		ucontrol->value.enumerated.item[0] = tascam->line_out_source;
+	}
+	return 0;
+}
+
+/*
+ * tascam_line_out_put() - ALSA control put callback for Line Outputs Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure containing the new value.
+ *
+ * This function sets the Line Outputs source (Playback 1-2 or Playback 3-4)
+ * based on the user's selection from the ALSA control element. It validates
+ * the input and updates the driver's private data.
+ *
+ * Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
+ */
+static int tascam_line_out_put(struct snd_kcontrol *kcontrol,
+			       struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (ucontrol->value.enumerated.item[0] > 1)
+		return -EINVAL;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		if (tascam->line_out_source != ucontrol->value.enumerated.item[0]) {
+			tascam->line_out_source = ucontrol->value.enumerated.item[0];
+			changed = 1;
+		}
+	}
+	return changed;
+}
+
+/*
+ * tascam_line_out_control - ALSA kcontrol definition for Line Outputs Source.
+ *
+ * This defines a new ALSA mixer control named "Line OUTPUTS Source" that allows
+ * the user to select between "Playback 1-2" and "Playback 3-4" for the analog
+ * line outputs of the device. It uses the `tascam_playback_source_info` for
+ * information and `tascam_line_out_get`/`tascam_line_out_put` for value
+ * handling.
+ */
+static const struct snd_kcontrol_new tascam_line_out_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Line Playback Source",
+	.info = tascam_playback_source_info,
+	.get = tascam_line_out_get,
+	.put = tascam_line_out_put,
+};
+
+/*
+ * tascam_digital_out_get() - ALSA control get callback for Digital Outputs
+ * Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure to fill.
+ *
+ * This function retrieves the current selection for the Digital Outputs source
+ * (Playback 1-2 or Playback 3-4) from the driver's private data and populates
+ * the ALSA control element value.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_digital_out_get(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		ucontrol->value.enumerated.item[0] = tascam->digital_out_source;
+	}
+	return 0;
+}
+
+/*
+ * tascam_digital_out_put() - ALSA control put callback for Digital Outputs
+ * Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure containing the new value.
+ *
+ * This function sets the Digital Outputs source (Playback 1-2 or Playback 3-4)
+ * based on the user's selection from the ALSA control element. It validates
+ * the input and updates the driver's private data.
+ *
+ * Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
+ */
+static int tascam_digital_out_put(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (ucontrol->value.enumerated.item[0] > 1)
+		return -EINVAL;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		if (tascam->digital_out_source != ucontrol->value.enumerated.item[0]) {
+			tascam->digital_out_source = ucontrol->value.enumerated.item[0];
+			changed = 1;
+		}
+	}
+	return changed;
+}
+
+/*
+ * tascam_digital_out_control - ALSA kcontrol definition for Digital Outputs
+ * Source.
+ *
+ * This defines a new ALSA mixer control named "Digital OUTPUTS Source" that
+ * allows the user to select between "Playback 1-2" and "Playback 3-4" for the
+ * digital outputs of the device. It uses the `tascam_playback_source_info` for
+ * information and `tascam_digital_out_get`/`tascam_digital_out_put` for value
+ * handling.
+ */
+static const struct snd_kcontrol_new tascam_digital_out_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Digital Playback Source",
+	.info = tascam_playback_source_info,
+	.get = tascam_digital_out_get,
+	.put = tascam_digital_out_put,
+};
+
+/*
+ * tascam_capture_source_info() - ALSA control info callback for capture source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @uinfo: The ALSA control element info structure to fill.
+ *
+ * This function provides information about the enumerated capture source
+ * control, including its type, count, and available items (Analog In, Digital
+ * In).
+ *
+ * Return: 0 on success.
+ */
+static int tascam_capture_source_info(struct snd_kcontrol *kcontrol,
+				      struct snd_ctl_elem_info *uinfo)
+{
+	return snd_ctl_enum_info(uinfo, 1, 2, capture_source_texts);
+}
+
+/*
+ * tascam_capture_12_get() - ALSA control get callback for Capture channels 1
+ * and 2 Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure to fill.
+ *
+ * This function retrieves the current selection for the Capture channels 1 and
+ * 2 source (Analog In or Digital In) from the driver's private data and
+ * populates the ALSA control element value.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_capture_12_get(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		ucontrol->value.enumerated.item[0] = tascam->capture_12_source;
+	}
+	return 0;
+}
+
+/*
+ * tascam_capture_12_put() - ALSA control put callback for Capture channels 1
+ * and 2 Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure containing the new value.
+ *
+ * This function sets the Capture channels 1 and 2 source (Analog In or Digital
+ * In) based on the user's selection from the ALSA control element. It validates
+ * the input and updates the driver's private data.
+ *
+ * Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
+ */
+static int tascam_capture_12_put(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (ucontrol->value.enumerated.item[0] > 1)
+		return -EINVAL;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		if (tascam->capture_12_source != ucontrol->value.enumerated.item[0]) {
+			tascam->capture_12_source = ucontrol->value.enumerated.item[0];
+			changed = 1;
+		}
+	}
+	return changed;
+}
+
+/*
+ * tascam_capture_12_control - ALSA kcontrol definition for Capture channels 1
+ * and 2 Source.
+ *
+ * This defines a new ALSA mixer control named "ch1 and ch2 Source" that allows
+ * the user to select between "Analog In" and "Digital In" for the first two
+ * capture channels of the device. It uses the `tascam_capture_source_info` for
+ * information and `tascam_capture_12_get`/`tascam_capture_12_put` for value
+ * handling.
+ */
+static const struct snd_kcontrol_new tascam_capture_12_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Ch1/2 Capture Source",
+	.info = tascam_capture_source_info,
+	.get = tascam_capture_12_get,
+	.put = tascam_capture_12_put,
+};
+
+/*
+ * tascam_capture_34_get() - ALSA control get callback for Capture channels 3
+ * and 4 Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure to fill.
+ *
+ * This function retrieves the current selection for the Capture channels 3 and
+ * 4 source (Analog In or Digital In) from the driver's private data and
+ * populates the ALSA control element value.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_capture_34_get(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		ucontrol->value.enumerated.item[0] = tascam->capture_34_source;
+	}
+	return 0;
+}
+
+/*
+ * tascam_capture_34_put() - ALSA control put callback for Capture channels 3
+ * and 4 Source.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure containing the new value.
+ *
+ * This function sets the Capture channels 3 and 4 source (Analog In or Digital
+ * In) based on the user's selection from the ALSA control element. It validates
+ * the input and updates the driver's private data.
+ *
+ * Return: 1 if the value was changed, 0 if unchanged, or a negative error code.
+ */
+static int tascam_capture_34_put(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (ucontrol->value.enumerated.item[0] > 1)
+		return -EINVAL;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		if (tascam->capture_34_source != ucontrol->value.enumerated.item[0]) {
+			tascam->capture_34_source = ucontrol->value.enumerated.item[0];
+			changed = 1;
+		}
+	}
+	return changed;
+}
+
+/*
+ * tascam_capture_34_control - ALSA kcontrol definition for Capture channels 3
+ * and 4 Source.
+ *
+ * This defines a new ALSA mixer control named "ch3 and ch4 Source" that allows
+ * the user to select between "Analog In" and "Digital In" for the third and
+ * fourth capture channels of the device. It uses the
+ * `tascam_capture_source_info` for information and
+ * `tascam_capture_34_get`/`tascam_capture_34_put` for value handling.
+ */
+static const struct snd_kcontrol_new tascam_capture_34_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Ch3/4 Capture Source",
+	.info = tascam_capture_source_info,
+	.get = tascam_capture_34_get,
+	.put = tascam_capture_34_put,
+};
+
+/*
+ * tascam_samplerate_info() - ALSA control info callback for Sample Rate.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @uinfo: The ALSA control element info structure to fill.
+ *
+ * This function provides information about the Sample Rate control, defining
+ * it as an integer type with a minimum value of 0 and a maximum of 96000.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_samplerate_info(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 96000;
+	return 0;
+}
+
+/*
+ * tascam_samplerate_get() - ALSA control get callback for Sample Rate.
+ * @kcontrol: The ALSA kcontrol instance.
+ * @ucontrol: The ALSA control element value structure to fill.
+ *
+ * This function retrieves the current sample rate from the device via a USB
+ * control message and populates the ALSA control element value. If the rate
+ * is already known (i.e., `current_rate` is set), it returns that value
+ * directly.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int tascam_samplerate_get(struct snd_kcontrol *kcontrol,
+				 struct snd_ctl_elem_value *ucontrol)
+{
+	struct tascam_card *tascam =
+		(struct tascam_card *)snd_kcontrol_chip(kcontrol);
+	int err;
+	u32 rate = 0;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		if (tascam->current_rate > 0) {
+			ucontrol->value.integer.value[0] = tascam->current_rate;
+			return 0;
+		}
+	}
+
+	u8 *buf __free(kfree) =
+		kmalloc(3, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	err = usb_control_msg(tascam->dev, usb_rcvctrlpipe(tascam->dev, 0),
+			      UAC_GET_CUR, RT_D2H_CLASS_EP,
+			      UAC_SAMPLING_FREQ_CONTROL, EP_AUDIO_IN, buf, 3,
+			      USB_CTRL_TIMEOUT_MS);
+
+	if (err >= 3)
+		rate = buf[0] | (buf[1] << 8) | (buf[2] << 16);
+
+	ucontrol->value.integer.value[0] = rate;
+	return 0;
+}
+
+/*
+ * tascam_samplerate_control - ALSA kcontrol definition for Sample Rate.
+ *
+ * This defines a new ALSA mixer control named "Sample Rate" that displays
+ * the current sample rate of the device. It is a read-only control.
+ */
+static const struct snd_kcontrol_new tascam_samplerate_control = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Sample Rate",
+	.info = tascam_samplerate_info,
+	.get = tascam_samplerate_get,
+	.access = SNDRV_CTL_ELEM_ACCESS_READ,
+};
+
+int tascam_create_controls(struct tascam_card *tascam)
+{
+	int err;
+
+	err = snd_ctl_add(tascam->card,
+			  snd_ctl_new1(&tascam_line_out_control, tascam));
+	if (err < 0)
+		return err;
+	err = snd_ctl_add(tascam->card,
+			  snd_ctl_new1(&tascam_digital_out_control, tascam));
+	if (err < 0)
+		return err;
+	err = snd_ctl_add(tascam->card,
+			  snd_ctl_new1(&tascam_capture_12_control, tascam));
+	if (err < 0)
+		return err;
+	err = snd_ctl_add(tascam->card,
+			  snd_ctl_new1(&tascam_capture_34_control, tascam));
+	if (err < 0)
+		return err;
+
+	err = snd_ctl_add(tascam->card,
+			  snd_ctl_new1(&tascam_samplerate_control, tascam));
+	if (err < 0)
+		return err;
+
+	return 0;
+}
diff --git a/sound/usb/usx2y/us144mkii_midi.c b/sound/usb/usx2y/us144mkii_midi.c
new file mode 100644
index 000000000..4871797b1
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii_midi.c
@@ -0,0 +1,403 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#include "us144mkii.h"
+
+/*
+ * tascam_midi_in_work_handler() - Deferred work for processing MIDI input.
+ * @work: The work_struct instance.
+ *
+ * This function runs in a thread context. It safely reads raw USB data from
+ * the kfifo, processes it by stripping protocol-specific padding bytes, and
+ * passes the clean MIDI data to the ALSA rawmidi subsystem.
+ */
+static void tascam_midi_in_work_handler(struct work_struct *work)
+{
+	struct tascam_card *tascam =
+		container_of(work, struct tascam_card, midi_in_work);
+	u8 buf[9];
+	u8 clean_buf[8];
+	unsigned int count, clean_count;
+
+	if (!tascam->midi_in_substream)
+		return;
+
+	while (kfifo_out_spinlocked(&tascam->midi_in_fifo, buf, sizeof(buf),
+				    &tascam->midi_in_lock) == sizeof(buf)) {
+		clean_count = 0;
+		for (count = 0; count < 8; ++count) {
+			if (buf[count] != 0xfd)
+				clean_buf[clean_count++] = buf[count];
+		}
+
+		if (clean_count > 0)
+			snd_rawmidi_receive(tascam->midi_in_substream,
+					    clean_buf, clean_count);
+	}
+}
+
+void tascam_midi_in_urb_complete(struct urb *urb)
+{
+	struct tascam_card *tascam = urb->context;
+	int ret;
+
+	if (!tascam)
+		goto out;
+
+	if (urb->status) {
+		if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
+		    urb->status != -ESHUTDOWN && urb->status != -EPROTO) {
+			dev_err_ratelimited(tascam->card->dev,
+					    "MIDI IN URB failed: status %d\n",
+					    urb->status);
+		}
+		goto out;
+	}
+
+	if (atomic_read(&tascam->midi_in_active) &&
+	    urb->actual_length > 0) {
+		kfifo_in_spinlocked(&tascam->midi_in_fifo, urb->transfer_buffer,
+				    urb->actual_length, &tascam->midi_in_lock);
+		schedule_work(&tascam->midi_in_work);
+	}
+
+	usb_get_urb(urb);
+	usb_anchor_urb(urb, &tascam->midi_in_anchor);
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret < 0) {
+		dev_err(tascam->card->dev,
+			"Failed to resubmit MIDI IN URB: error %d\n", ret);
+		usb_unanchor_urb(urb);
+		goto out;
+	}
+
+out:
+	usb_put_urb(urb);
+}
+
+/*
+ * tascam_midi_in_open() - Opens the MIDI input substream.
+ * @substream: The ALSA rawmidi substream to open.
+ *
+ * This function stores a reference to the MIDI input substream in the
+ * driver's private data.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_midi_in_open(struct snd_rawmidi_substream *substream)
+{
+	struct tascam_card *tascam = substream->rmidi->private_data;
+
+	tascam->midi_in_substream = substream;
+	return 0;
+}
+
+/*
+ * tascam_midi_in_close() - Closes the MIDI input substream.
+ * @substream: The ALSA rawmidi substream to close.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_midi_in_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+/*
+ * tascam_midi_in_trigger() - Triggers MIDI input stream activity.
+ * @substream: The ALSA rawmidi substream.
+ * @up: Boolean indicating whether to start (1) or stop (0) the stream.
+ *
+ * This function starts or stops the MIDI input URBs based on the 'up'
+ * parameter. When starting, it resets the kfifo and submits all MIDI input
+ * URBs. When stopping, it kills all anchored MIDI input URBs and cancels the
+ * associated workqueue.
+ */
+static void tascam_midi_in_trigger(struct snd_rawmidi_substream *substream,
+				   int up)
+{
+	struct tascam_card *tascam = substream->rmidi->private_data;
+	int i, err;
+
+	if (up) {
+		if (atomic_xchg(&tascam->midi_in_active, 1) == 0) {
+			scoped_guard(spinlock_irqsave, &tascam->midi_in_lock)
+			{
+				kfifo_reset(&tascam->midi_in_fifo);
+			}
+
+			for (i = 0; i < NUM_MIDI_IN_URBS; i++) {
+				usb_get_urb(tascam->midi_in_urbs[i]);
+				usb_anchor_urb(tascam->midi_in_urbs[i],
+						       &tascam->midi_in_anchor);
+				err = usb_submit_urb(tascam->midi_in_urbs[i],
+							     GFP_KERNEL);
+				if (err < 0) {
+					dev_err(tascam->card->dev,
+						"Failed to submit MIDI IN URB %d: %d\n",
+						i, err);
+					usb_unanchor_urb(
+							tascam->midi_in_urbs[i]);
+					usb_put_urb(tascam->midi_in_urbs[i]);
+				}
+			}
+		}
+	} else {
+		if (atomic_xchg(&tascam->midi_in_active, 0) == 1) {
+			usb_kill_anchored_urbs(&tascam->midi_in_anchor);
+			cancel_work_sync(&tascam->midi_in_work);
+		}
+	}
+}
+
+/*
+ * tascam_midi_in_ops - ALSA rawmidi operations for MIDI input.
+ *
+ * This structure defines the callback functions for MIDI input stream
+ * operations, including open, close, and trigger.
+ */
+static const struct snd_rawmidi_ops tascam_midi_in_ops = {
+	.open = tascam_midi_in_open,
+	.close = tascam_midi_in_close,
+	.trigger = tascam_midi_in_trigger,
+};
+
+void tascam_midi_out_urb_complete(struct urb *urb)
+{
+	struct tascam_card *tascam = urb->context;
+	int i, urb_index = -1;
+
+	if (urb->status) {
+		if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
+		    urb->status != -ESHUTDOWN) {
+			dev_err_ratelimited(tascam->card->dev,
+					    "MIDI OUT URB failed: %d\n",
+					    urb->status);
+		}
+		goto out;
+	}
+
+	if (!tascam)
+		goto out;
+
+	for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
+		if (tascam->midi_out_urbs[i] == urb) {
+			urb_index = i;
+			break;
+		}
+	}
+
+	if (urb_index < 0) {
+		dev_err_ratelimited(tascam->card->dev,
+				    "Unknown MIDI OUT URB completed!\n");
+		goto out;
+	}
+
+	scoped_guard(spinlock_irqsave, &tascam->midi_out_lock)
+	{
+		clear_bit(urb_index, &tascam->midi_out_urbs_in_flight);
+	}
+
+	if (atomic_read(&tascam->midi_out_active))
+		schedule_work(&tascam->midi_out_work);
+
+out:
+	usb_put_urb(urb);
+}
+
+/*
+ * tascam_midi_out_work_handler() - Deferred work for sending MIDI data
+ * @work: The work_struct instance.
+ *
+ * This function handles the proprietary output protocol: take the raw MIDI
+ * message bytes from the application, place them at the start of a 9-byte
+ * buffer, pad the rest with 0xFD, and add a terminator byte (0x00).
+ * This function pulls as many bytes as will fit into one packet from the
+ * ALSA buffer and sends them.
+ */
+static void tascam_midi_out_work_handler(struct work_struct *work)
+{
+	struct tascam_card *tascam =
+		container_of(work, struct tascam_card, midi_out_work);
+	struct snd_rawmidi_substream *substream = tascam->midi_out_substream;
+	int i;
+
+	if (!substream || !atomic_read(&tascam->midi_out_active))
+		return;
+
+	while (snd_rawmidi_transmit_peek(substream, (u8[]){ 0 }, 1) == 1) {
+		int urb_index;
+		struct urb *urb;
+		u8 *buf;
+		int bytes_to_send;
+
+		scoped_guard(spinlock_irqsave, &tascam->midi_out_lock) {
+			urb_index = -1;
+			for (i = 0; i < NUM_MIDI_OUT_URBS; i++) {
+				if (!test_bit(
+					    i,
+					    &tascam->midi_out_urbs_in_flight)) {
+					urb_index = i;
+					break;
+				}
+			}
+
+			if (urb_index < 0)
+				return; /* No free URBs, will be rescheduled by
+					 * completion handler
+					 */
+
+			urb = tascam->midi_out_urbs[urb_index];
+			buf = urb->transfer_buffer;
+			bytes_to_send = snd_rawmidi_transmit(substream, buf, 8);
+
+			if (bytes_to_send <= 0)
+				break; /* No more data */
+
+			if (bytes_to_send < 9)
+				memset(buf + bytes_to_send, 0xfd,
+				       9 - bytes_to_send);
+			buf[8] = 0xe0;
+
+			set_bit(urb_index, &tascam->midi_out_urbs_in_flight);
+			urb->transfer_buffer_length = 9;
+		}
+
+		usb_get_urb(urb);
+		usb_anchor_urb(urb, &tascam->midi_out_anchor);
+		if (usb_submit_urb(urb, GFP_KERNEL) < 0) {
+			dev_err_ratelimited(
+					tascam->card->dev,
+					"Failed to submit MIDI OUT URB %d\n",
+										urb_index);
+			scoped_guard(spinlock_irqsave, &tascam->midi_out_lock)
+			{
+				clear_bit(urb_index,
+					  &tascam->midi_out_urbs_in_flight);
+			}
+			usb_unanchor_urb(urb);
+			usb_put_urb(urb);
+			break; /* Stop on error */
+		}
+	}
+}
+
+/*
+ * tascam_midi_out_open() - Opens the MIDI output substream.
+ * @substream: The ALSA rawmidi substream to open.
+ *
+ * This function stores a reference to the MIDI output substream in the
+ * driver's private data and initializes the MIDI running status.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_midi_out_open(struct snd_rawmidi_substream *substream)
+{
+	struct tascam_card *tascam = substream->rmidi->private_data;
+
+	tascam->midi_out_substream = substream;
+	/* Initialize the running status state for the packet packer. */
+	tascam->midi_running_status = 0;
+	return 0;
+}
+
+/*
+ * tascam_midi_out_close() - Closes the MIDI output substream.
+ * @substream: The ALSA rawmidi substream to close.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_midi_out_close(struct snd_rawmidi_substream *substream)
+{
+	return 0;
+}
+
+/*
+ * tascam_midi_out_drain() - Drains the MIDI output stream.
+ * @substream: The ALSA rawmidi substream.
+ *
+ * This function cancels any pending MIDI output work and kills all
+ * anchored MIDI output URBs, ensuring all data is sent or discarded.
+ */
+static void tascam_midi_out_drain(struct snd_rawmidi_substream *substream)
+{
+	struct tascam_card *tascam = substream->rmidi->private_data;
+	bool in_flight = true;
+
+	while (in_flight) {
+		in_flight = false;
+		for (int i = 0; i < NUM_MIDI_OUT_URBS; i++) {
+			if (test_bit(i, &tascam->midi_out_urbs_in_flight)) {
+				in_flight = true;
+				break;
+			}
+		}
+		if (in_flight)
+			schedule_timeout_uninterruptible(1);
+	}
+
+	cancel_work_sync(&tascam->midi_out_work);
+	usb_kill_anchored_urbs(&tascam->midi_out_anchor);
+}
+
+/*
+ * tascam_midi_out_trigger() - Triggers MIDI output stream activity.
+ * @substream: The ALSA rawmidi substream.
+ * @up: Boolean indicating whether to start (1) or stop (0) the stream.
+ *
+ * This function starts or stops the MIDI output workqueue based on the
+ * 'up' parameter.
+ */
+static void tascam_midi_out_trigger(struct snd_rawmidi_substream *substream,
+				    int up)
+{
+	struct tascam_card *tascam = substream->rmidi->private_data;
+
+	if (up) {
+		atomic_set(&tascam->midi_out_active, 1);
+		schedule_work(&tascam->midi_out_work);
+	} else {
+		atomic_set(&tascam->midi_out_active, 0);
+	}
+}
+
+/*
+ * tascam_midi_out_ops - ALSA rawmidi operations for MIDI output.
+ *
+ * This structure defines the callback functions for MIDI output stream
+ * operations, including open, close, trigger, and drain.
+ */
+static const struct snd_rawmidi_ops tascam_midi_out_ops = {
+	.open = tascam_midi_out_open,
+	.close = tascam_midi_out_close,
+	.trigger = tascam_midi_out_trigger,
+	.drain = tascam_midi_out_drain,
+};
+
+int tascam_create_midi(struct tascam_card *tascam)
+{
+	int err;
+
+	err = snd_rawmidi_new(tascam->card, "US144MKII MIDI", 0, 1, 1,
+			      &tascam->rmidi);
+	if (err < 0)
+		return err;
+
+	strscpy(tascam->rmidi->name, "US144MKII MIDI",
+		sizeof(tascam->rmidi->name));
+	tascam->rmidi->private_data = tascam;
+
+	snd_rawmidi_set_ops(tascam->rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+			    &tascam_midi_in_ops);
+	snd_rawmidi_set_ops(tascam->rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+			    &tascam_midi_out_ops);
+
+	tascam->rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT |
+				     SNDRV_RAWMIDI_INFO_OUTPUT |
+				     SNDRV_RAWMIDI_INFO_DUPLEX;
+
+	INIT_WORK(&tascam->midi_in_work, tascam_midi_in_work_handler);
+	INIT_WORK(&tascam->midi_out_work, tascam_midi_out_work_handler);
+
+	return 0;
+}
diff --git a/sound/usb/usx2y/us144mkii_pcm.c b/sound/usb/usx2y/us144mkii_pcm.c
new file mode 100644
index 000000000..03dfb1f38
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii_pcm.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#include "us144mkii.h"
+
+/**
+ * fpo_init_pattern() - Generates a packet distribution pattern.
+ * @size: The number of elements in the pattern array (e.g., 8).
+ * @pattern_array: Pointer to the array to be populated.
+ * @initial_value: The base value to initialize each element with.
+ * @target_sum: The desired sum of all elements in the final array.
+ *
+ * This function initializes an array with a base value and then iteratively
+ * adjusts the elements to match a target sum, distributing the difference
+ * as evenly as possible.
+ */
+static void fpo_init_pattern(unsigned int size, unsigned int *pattern_array,
+	unsigned int initial_value, int target_sum)
+{
+	int diff, i;
+
+	if (!size)
+		return;
+
+	for (i = 0; i < size; ++i)
+		pattern_array[i] = initial_value;
+
+	diff = target_sum - (size * initial_value);
+	for (i = 0; i < abs(diff); ++i) {
+		if (diff > 0)
+			pattern_array[i]++;
+		else
+			pattern_array[i]--;
+	}
+}
+
+const struct snd_pcm_hardware tascam_pcm_hw = {
+	.info = (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
+		 SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP_VALID |
+		 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME),
+	.formats = SNDRV_PCM_FMTBIT_S24_3LE,
+	.rates = (SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
+		  SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000),
+	.rate_min = 44100,
+	.rate_max = 96000,
+	.channels_min = NUM_CHANNELS,
+	.channels_max = NUM_CHANNELS,
+	.buffer_bytes_max = 1024 * 1024,
+	.period_bytes_min = 48 * BYTES_PER_FRAME,
+	.period_bytes_max = 1024 * BYTES_PER_FRAME,
+	.periods_min = 2,
+	.periods_max = 1024,
+};
+
+void process_playback_routing_us144mkii(struct tascam_card *tascam,
+					const u8 *src_buffer, u8 *dst_buffer,
+					size_t frames)
+{
+	size_t f;
+	const u8 *src_12, *src_34;
+	u8 *dst_line, *dst_digital;
+
+	for (f = 0; f < frames; ++f) {
+		src_12 = src_buffer + f * BYTES_PER_FRAME;
+		src_34 = src_12 + (2 * BYTES_PER_SAMPLE);
+		dst_line = dst_buffer + f * BYTES_PER_FRAME;
+		dst_digital = dst_line + (2 * BYTES_PER_SAMPLE);
+
+		/* LINE OUTPUTS (ch1/2 on device) */
+		if (tascam->line_out_source == 0) /* "ch1 and ch2" */
+			memcpy(dst_line, src_12, 2 * BYTES_PER_SAMPLE);
+		else /* "ch3 and ch4" */
+			memcpy(dst_line, src_34, 2 * BYTES_PER_SAMPLE);
+
+		/* DIGITAL OUTPUTS (ch3/4 on device) */
+		if (tascam->digital_out_source == 0) /* "ch1 and ch2" */
+			memcpy(dst_digital, src_12, 2 * BYTES_PER_SAMPLE);
+		else /* "ch3 and ch4" */
+			memcpy(dst_digital, src_34, 2 * BYTES_PER_SAMPLE);
+	}
+}
+
+void process_capture_routing_us144mkii(struct tascam_card *tascam,
+				       const s32 *decoded_block,
+				       s32 *routed_block)
+{
+	int f;
+	const s32 *src_frame;
+	s32 *dst_frame;
+
+	for (f = 0; f < FRAMES_PER_DECODE_BLOCK; f++) {
+		src_frame = decoded_block + (f * DECODED_CHANNELS_PER_FRAME);
+		dst_frame = routed_block + (f * DECODED_CHANNELS_PER_FRAME);
+
+		/* ch1 and ch2 Source */
+		if (tascam->capture_12_source == 0) { /* analog inputs */
+			dst_frame[0] = src_frame[0]; /* Analog L */
+			dst_frame[1] = src_frame[1]; /* Analog R */
+		} else { /* digital inputs */
+			dst_frame[0] = src_frame[2]; /* Digital L */
+			dst_frame[1] = src_frame[3]; /* Digital R */
+		}
+
+		/* ch3 and ch4 Source */
+		if (tascam->capture_34_source == 0) { /* analog inputs */
+			dst_frame[2] = src_frame[0]; /* Analog L (Duplicate) */
+			dst_frame[3] = src_frame[1]; /* Analog R (Duplicate) */
+		} else { /* digital inputs */
+			dst_frame[2] = src_frame[2]; /* Digital L */
+			dst_frame[3] = src_frame[3]; /* Digital R */
+		}
+	}
+}
+
+int us144mkii_configure_device_for_rate(struct tascam_card *tascam, int rate)
+{
+	struct usb_device *dev = tascam->dev;
+	u16 rate_vendor_wValue;
+	int err = 0;
+	const u8 *current_payload_src;
+
+	static const u8 payload_44100[] = { 0x44, 0xac, 0x00 };
+	static const u8 payload_48000[] = { 0x80, 0xbb, 0x00 };
+	static const u8 payload_88200[] = { 0x88, 0x58, 0x01 };
+	static const u8 payload_96000[] = { 0x00, 0x77, 0x01 };
+
+	switch (rate) {
+	case 44100:
+		current_payload_src = payload_44100;
+		rate_vendor_wValue = REG_ADDR_RATE_44100;
+		break;
+	case 48000:
+		current_payload_src = payload_48000;
+		rate_vendor_wValue = REG_ADDR_RATE_48000;
+		break;
+	case 88200:
+		current_payload_src = payload_88200;
+		rate_vendor_wValue = REG_ADDR_RATE_88200;
+		break;
+	case 96000:
+		current_payload_src = payload_96000;
+		rate_vendor_wValue = REG_ADDR_RATE_96000;
+		break;
+	default:
+		dev_err(&dev->dev,
+			"Unsupported sample rate %d for configuration\n", rate);
+		return -EINVAL;
+	}
+
+	u8 *rate_payload_buf __free(kfree) =
+		kmemdup(current_payload_src, 3, GFP_KERNEL);
+	if (!rate_payload_buf)
+		return -ENOMEM;
+
+	dev_info(&dev->dev, "Configuring device for %d Hz\n", rate);
+
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_MODE_CONTROL, RT_H2D_VENDOR_DEV,
+			      MODE_VAL_CONFIG, 0x0000, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
+			      RT_H2D_CLASS_EP, UAC_SAMPLING_FREQ_CONTROL,
+			      EP_AUDIO_IN, rate_payload_buf, 3,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
+			      RT_H2D_CLASS_EP, UAC_SAMPLING_FREQ_CONTROL,
+			      EP_AUDIO_OUT, rate_payload_buf, 3,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_REGISTER_WRITE, RT_H2D_VENDOR_DEV,
+			      REG_ADDR_UNKNOWN_0D, REG_VAL_ENABLE, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_REGISTER_WRITE, RT_H2D_VENDOR_DEV,
+			      REG_ADDR_UNKNOWN_0E, REG_VAL_ENABLE, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_REGISTER_WRITE, RT_H2D_VENDOR_DEV,
+			      REG_ADDR_UNKNOWN_0F, REG_VAL_ENABLE, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_REGISTER_WRITE, RT_H2D_VENDOR_DEV,
+			      rate_vendor_wValue, REG_VAL_ENABLE, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_REGISTER_WRITE, RT_H2D_VENDOR_DEV,
+			      REG_ADDR_UNKNOWN_11, REG_VAL_ENABLE, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+			      VENDOR_REQ_MODE_CONTROL, RT_H2D_VENDOR_DEV,
+			      MODE_VAL_STREAM_START, 0x0000, NULL, 0,
+			      USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		goto fail;
+	return 0;
+
+fail:
+	dev_err(&dev->dev,
+		"Device configuration failed at rate %d with error %d\n", rate,
+		err);
+	return err;
+}
+
+int tascam_pcm_hw_params(struct snd_pcm_substream *substream,
+					 struct snd_pcm_hw_params *params)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+	int err;
+	unsigned int rate = params_rate(params);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		tascam->fpo.sample_rate_khz = rate / 1000;
+		tascam->fpo.base_feedback_value = tascam->fpo.sample_rate_khz;
+		tascam->fpo.feedback_offset = 2;
+		tascam->fpo.current_index = 0;
+		tascam->fpo.previous_index = 0;
+		tascam->fpo.sync_locked = false;
+
+		unsigned int initial_value = tascam->fpo.sample_rate_khz / 8;
+
+		for (int i = 0; i < 5; i++) {
+			int target_sum = tascam->fpo.sample_rate_khz -
+					 tascam->fpo.feedback_offset + i;
+			fpo_init_pattern(8, tascam->fpo.full_frame_patterns[i],
+					       initial_value, target_sum);
+		}
+	}
+
+	if (tascam->current_rate != rate) {
+		err = us144mkii_configure_device_for_rate(tascam, rate);
+		if (err < 0) {
+			tascam->current_rate = 0;
+			return err;
+		}
+		tascam->current_rate = rate;
+	}
+
+	return 0;
+}
+
+int tascam_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+int tascam_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+	int err = 0;
+	int i;
+	bool do_start = false;
+	bool do_stop = false;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		switch (cmd) {
+		case SNDRV_PCM_TRIGGER_START:
+		case SNDRV_PCM_TRIGGER_RESUME:
+			if (!atomic_read(&tascam->playback_active)) {
+				atomic_set(&tascam->playback_active, 1);
+				atomic_set(&tascam->capture_active, 1);
+				do_start = true;
+			}
+			break;
+		case SNDRV_PCM_TRIGGER_STOP:
+		case SNDRV_PCM_TRIGGER_SUSPEND:
+		case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+			if (atomic_read(&tascam->playback_active)) {
+				atomic_set(&tascam->playback_active, 0);
+				atomic_set(&tascam->capture_active, 0);
+				do_stop = true;
+			}
+			break;
+		default:
+			err = -EINVAL;
+			break;
+		}
+	}
+
+	if (do_start) {
+		if (atomic_read(&tascam->active_urbs) > 0) {
+			dev_warn(tascam->card->dev,
+				 "Cannot start, URBs still active.\n");
+			return -EAGAIN;
+		}
+
+		for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
+			usb_get_urb(tascam->feedback_urbs[i]);
+			usb_anchor_urb(tascam->feedback_urbs[i],
+					       &tascam->feedback_anchor);
+			err = usb_submit_urb(tascam->feedback_urbs[i],
+						     GFP_ATOMIC);
+			if (err < 0) {
+				usb_unanchor_urb(tascam->feedback_urbs[i]);
+				usb_put_urb(tascam->feedback_urbs[i]);
+				atomic_dec(&tascam->active_urbs);
+				goto start_rollback;
+			}
+			atomic_inc(&tascam->active_urbs);
+		}
+		for (i = 0; i < NUM_PLAYBACK_URBS; i++) {
+			usb_get_urb(tascam->playback_urbs[i]);
+			usb_anchor_urb(tascam->playback_urbs[i],
+					       &tascam->playback_anchor);
+			err = usb_submit_urb(tascam->playback_urbs[i],
+						     GFP_ATOMIC);
+			if (err < 0) {
+				usb_unanchor_urb(tascam->playback_urbs[i]);
+				usb_put_urb(tascam->playback_urbs[i]);
+				atomic_dec(&tascam->active_urbs);
+				goto start_rollback;
+			}
+			atomic_inc(&tascam->active_urbs);
+		}
+		for (i = 0; i < NUM_CAPTURE_URBS; i++) {
+			usb_get_urb(tascam->capture_urbs[i]);
+			usb_anchor_urb(tascam->capture_urbs[i],
+				       &tascam->capture_anchor);
+			err = usb_submit_urb(tascam->capture_urbs[i],
+					     GFP_ATOMIC);
+			if (err < 0) {
+				usb_unanchor_urb(tascam->capture_urbs[i]);
+				usb_put_urb(tascam->capture_urbs[i]);
+				atomic_dec(&tascam->active_urbs);
+				goto start_rollback;
+			}
+			atomic_inc(&tascam->active_urbs);
+		}
+
+		return 0;
+start_rollback:
+		dev_err(tascam->card->dev,
+			"Failed to submit URBs to start stream: %d\n", err);
+		do_stop = true;
+	}
+
+	if (do_stop)
+		schedule_work(&tascam->stop_work);
+
+	return err;
+}
+
+int tascam_init_pcm(struct snd_pcm *pcm)
+{
+	struct tascam_card *tascam = pcm->private_data;
+
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &tascam_playback_ops);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tascam_capture_ops);
+
+	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
+				       tascam->dev->dev.parent, 64 * 1024,
+				       tascam_pcm_hw.buffer_bytes_max);
+
+	return 0;
+}
diff --git a/sound/usb/usx2y/us144mkii_pcm.h b/sound/usb/usx2y/us144mkii_pcm.h
new file mode 100644
index 000000000..a13067840
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii_pcm.h
@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#ifndef __US144MKII_PCM_H
+#define __US144MKII_PCM_H
+
+#include "us144mkii.h"
+
+/**
+ * var tascam_pcm_hw - Hardware capabilities for TASCAM US-144MKII PCM.
+ *
+ * Defines the supported PCM formats, rates, channels, and buffer/period sizes
+ * for the TASCAM US-144MKII audio interface.
+ */
+extern const struct snd_pcm_hardware tascam_pcm_hw;
+
+/**
+ * var tascam_playback_ops - ALSA PCM operations for playback.
+ *
+ * This structure defines the callback functions for playback stream operations.
+ */
+extern const struct snd_pcm_ops tascam_playback_ops;
+
+/**
+ * var tascam_capture_ops - ALSA PCM operations for capture.
+ *
+ * This structure defines the callback functions for capture stream operations.
+ */
+extern const struct snd_pcm_ops tascam_capture_ops;
+
+/**
+ * playback_urb_complete() - Completion handler for playback isochronous URBs.
+ * @urb: the completed URB
+ *
+ * This function runs in interrupt context. It calculates the number of bytes
+ * to send in the next set of packets based on the feedback-driven clock,
+ * copies the audio data from the ALSA ring buffer, and resubmits the URB.
+ */
+void playback_urb_complete(struct urb *urb);
+
+/**
+ * feedback_urb_complete() - Completion handler for feedback isochronous URBs.
+ * @urb: the completed URB
+ *
+ * This is the master clock for the driver. It runs in interrupt context.
+ * It reads the feedback value from the device, which indicates how many
+ * samples the device has consumed. This information is used to adjust the
+ * playback rate and to advance the capture stream pointer, keeping both
+ * streams in sync. It then calls snd_pcm_period_elapsed if necessary and
+ * resubmits itself.
+ */
+void feedback_urb_complete(struct urb *urb);
+
+/**
+ * capture_urb_complete() - Completion handler for capture bulk URBs.
+ * @urb: the completed URB
+ *
+ * This function runs in interrupt context. It copies the received raw data
+ * into an intermediate ring buffer and then schedules the workqueue to process
+ * it. It then resubmits the URB to receive more data.
+ */
+void capture_urb_complete(struct urb *urb);
+
+/**
+ * tascam_stop_pcm_work_handler() - Work handler to stop PCM streams.
+ * @work: Pointer to the work_struct.
+ *
+ * This function is scheduled to stop PCM streams (playback and capture)
+ * from a workqueue context, avoiding blocking operations in interrupt context.
+ */
+void tascam_stop_pcm_work_handler(struct work_struct *work);
+
+/**
+ * tascam_init_pcm() - Initializes the ALSA PCM device.
+ * @pcm: Pointer to the ALSA PCM device to initialize.
+ *
+ * This function sets up the PCM operations, adds ALSA controls for routing
+ * and sample rate, and preallocates pages for the PCM buffer.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int tascam_init_pcm(struct snd_pcm *pcm);
+
+/**
+ * us144mkii_configure_device_for_rate() - Set sample rate via USB control msgs
+ * @tascam: the tascam_card instance
+ * @rate: the target sample rate (e.g., 44100, 96000)
+ *
+ * This function sends a sequence of vendor-specific and UAC control messages
+ * to configure the device hardware for the specified sample rate.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int us144mkii_configure_device_for_rate(struct tascam_card *tascam, int rate);
+
+/**
+ * process_playback_routing_us144mkii() - Apply playback routing matrix
+ * @tascam: The driver instance.
+ * @src_buffer: Buffer containing 4 channels of S24_3LE audio from ALSA.
+ * @dst_buffer: Buffer to be filled for the USB device.
+ * @frames: Number of frames to process.
+ */
+void process_playback_routing_us144mkii(struct tascam_card *tascam,
+					const u8 *src_buffer, u8 *dst_buffer,
+					size_t frames);
+
+/**
+ * process_capture_routing_us144mkii() - Apply capture routing matrix
+ * @tascam: The driver instance.
+ * @decoded_block: Buffer containing 4 channels of S32LE decoded audio.
+ * @routed_block: Buffer to be filled for ALSA.
+ */
+void process_capture_routing_us144mkii(struct tascam_card *tascam,
+				       const s32 *decoded_block,
+				       s32 *routed_block);
+
+/**
+ * tascam_pcm_hw_params() - Configures hardware parameters for PCM streams.
+ * @substream: The ALSA PCM substream.
+ * @params: The hardware parameters to apply.
+ *
+ * This function allocates pages for the PCM buffer and, for playback streams,
+ * selects the appropriate feedback patterns based on the requested sample rate.
+ * It also configures the device hardware for the selected sample rate if it
+ * has changed.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int tascam_pcm_hw_params(struct snd_pcm_substream *substream,
+			 struct snd_pcm_hw_params *params);
+
+/**
+ * tascam_pcm_hw_free() - Frees hardware parameters for PCM streams.
+ * @substream: The ALSA PCM substream.
+ *
+ * This function is a stub for freeing hardware-related resources.
+ *
+ * Return: 0 on success.
+ */
+int tascam_pcm_hw_free(struct snd_pcm_substream *substream);
+
+/**
+ * tascam_pcm_trigger() - Triggers the start or stop of PCM streams.
+ * @substream: The ALSA PCM substream.
+ * @cmd: The trigger command (e.g., SNDRV_PCM_TRIGGER_START).
+ *
+ * This function handles starting and stopping of playback and capture streams
+ * by submitting or killing the associated URBs.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+int tascam_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
+
+/**
+ * tascam_capture_work_handler() - Deferred work for processing capture data.
+ * @work: the work_struct instance
+ *
+ * This function runs in a kernel thread context, not an IRQ context. It reads
+ * raw data from the capture ring buffer, decodes it, applies routing, and
+ * copies the final audio data into the ALSA capture ring buffer. This offloads
+ * the CPU-intensive decoding from the time-sensitive URB completion handlers.
+ */
+void tascam_capture_work_handler(struct work_struct *work);
+
+#endif /* __US144MKII_PCM_H */
diff --git a/sound/usb/usx2y/us144mkii_playback.c b/sound/usb/usx2y/us144mkii_playback.c
new file mode 100644
index 000000000..7efaca0a6
--- /dev/null
+++ b/sound/usb/usx2y/us144mkii_playback.c
@@ -0,0 +1,456 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2025 Šerif Rami <ramiserifpersia@gmail.com>
+
+#include "us144mkii.h"
+
+/*
+ * tascam_playback_open() - Opens the PCM playback substream.
+ * @substream: The ALSA PCM substream to open.
+ *
+ * This function sets the hardware parameters for the playback substream
+ * and stores a reference to the substream in the driver's private data.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_playback_open(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+
+	substream->runtime->hw = tascam_pcm_hw;
+	tascam->playback_substream = substream;
+	atomic_set(&tascam->playback_active, 0);
+
+	return 0;
+}
+
+/*
+ * tascam_playback_close() - Closes the PCM playback substream.
+ * @substream: The ALSA PCM substream to close.
+ *
+ * This function clears the reference to the playback substream in the
+ * driver's private data.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_playback_close(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+
+	tascam->playback_substream = NULL;
+
+	return 0;
+}
+
+/*
+ * tascam_playback_prepare() - Prepares the PCM playback substream for use.
+ * @substream: The ALSA PCM substream to prepare.
+ *
+ * This function initializes playback-related counters and flags, and configures
+ * the playback URBs with appropriate packet sizes based on the nominal frame
+ * rate.
+ *
+ * Return: 0 on success.
+ */
+static int tascam_playback_prepare(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	int i, u;
+	size_t nominal_frames_per_packet, nominal_bytes_per_packet;
+	size_t total_bytes_in_urb;
+
+	tascam->driver_playback_pos = 0;
+	tascam->playback_frames_consumed = 0;
+	tascam->last_period_pos = 0;
+	tascam->feedback_pattern_in_idx = 0;
+	tascam->feedback_pattern_out_idx = 0;
+	tascam->feedback_synced = false;
+	tascam->feedback_consecutive_errors = 0;
+	tascam->feedback_urb_skip_count = NUM_FEEDBACK_URBS;
+
+	nominal_frames_per_packet = runtime->rate / 8000;
+	for (i = 0; i < FEEDBACK_ACCUMULATOR_SIZE; i++)
+		tascam->feedback_accumulator_pattern[i] =
+			nominal_frames_per_packet;
+
+	for (i = 0; i < NUM_FEEDBACK_URBS; i++) {
+		struct urb *f_urb = tascam->feedback_urbs[i];
+		int j;
+
+		f_urb->number_of_packets = FEEDBACK_URB_PACKETS;
+		f_urb->transfer_buffer_length =
+			FEEDBACK_URB_PACKETS * FEEDBACK_PACKET_SIZE;
+		for (j = 0; j < FEEDBACK_URB_PACKETS; j++) {
+			f_urb->iso_frame_desc[j].offset =
+				j * FEEDBACK_PACKET_SIZE;
+			f_urb->iso_frame_desc[j].length = FEEDBACK_PACKET_SIZE;
+		}
+	}
+
+	nominal_bytes_per_packet = nominal_frames_per_packet * BYTES_PER_FRAME;
+	total_bytes_in_urb = nominal_bytes_per_packet * PLAYBACK_URB_PACKETS;
+
+	for (u = 0; u < NUM_PLAYBACK_URBS; u++) {
+		struct urb *urb = tascam->playback_urbs[u];
+
+		memset(urb->transfer_buffer, 0,
+		       tascam->playback_urb_alloc_size);
+		urb->transfer_buffer_length = total_bytes_in_urb;
+		urb->number_of_packets = PLAYBACK_URB_PACKETS;
+		for (i = 0; i < PLAYBACK_URB_PACKETS; i++) {
+			urb->iso_frame_desc[i].offset =
+				i * nominal_bytes_per_packet;
+			urb->iso_frame_desc[i].length =
+				nominal_bytes_per_packet;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * tascam_playback_pointer() - Returns the current playback pointer position.
+ * @substream: The ALSA PCM substream.
+ *
+ * This function returns the current position of the playback pointer within
+ * the ALSA ring buffer, in frames.
+ *
+ * Return: The current playback pointer position in frames.
+ */
+static snd_pcm_uframes_t
+tascam_playback_pointer(struct snd_pcm_substream *substream)
+{
+	struct tascam_card *tascam = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	u64 pos;
+
+	if (!atomic_read(&tascam->playback_active))
+		return 0;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		pos = tascam->playback_frames_consumed;
+	}
+
+	if (runtime->buffer_size == 0)
+		return 0;
+
+	return do_div(pos, runtime->buffer_size);
+}
+
+/*
+ * tascam_playback_ops - ALSA PCM operations for playback.
+ *
+ * This structure defines the callback functions for playback stream operations,
+ * including open, close, ioctl, hardware parameters, hardware free, prepare,
+ * trigger, and pointer.
+ */
+const struct snd_pcm_ops tascam_playback_ops = {
+	.open = tascam_playback_open,
+	.close = tascam_playback_close,
+	.ioctl = snd_pcm_lib_ioctl,
+	.hw_params = tascam_pcm_hw_params,
+	.hw_free = tascam_pcm_hw_free,
+	.prepare = tascam_playback_prepare,
+	.trigger = tascam_pcm_trigger,
+	.pointer = tascam_playback_pointer,
+};
+
+void playback_urb_complete(struct urb *urb)
+{
+	struct tascam_card *tascam = urb->context;
+	struct snd_pcm_substream *substream;
+	struct snd_pcm_runtime *runtime;
+	size_t total_bytes_for_urb = 0;
+	snd_pcm_uframes_t offset_frames;
+	snd_pcm_uframes_t frames_to_copy;
+	int ret, i;
+
+	if (urb->status) {
+		if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
+		    urb->status != -ESHUTDOWN && urb->status != -ENODEV)
+			dev_err_ratelimited(tascam->card->dev,
+					    "Playback URB failed: %d\n",
+					    urb->status);
+		goto out;
+	}
+	if (!tascam || !atomic_read(&tascam->playback_active))
+		goto out;
+
+	substream = tascam->playback_substream;
+	if (!substream || !substream->runtime)
+		goto out;
+	runtime = substream->runtime;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		for (i = 0; i < urb->number_of_packets; i++) {
+			unsigned int frames_for_packet;
+			size_t bytes_for_packet;
+
+			if (tascam->feedback_synced) {
+				frames_for_packet =
+					tascam->feedback_accumulator_pattern
+						[tascam->feedback_pattern_out_idx];
+				tascam->feedback_pattern_out_idx =
+					(tascam->feedback_pattern_out_idx + 1) %
+					FEEDBACK_ACCUMULATOR_SIZE;
+			} else {
+				frames_for_packet = runtime->rate / 8000;
+			}
+			bytes_for_packet = frames_for_packet * BYTES_PER_FRAME;
+
+			urb->iso_frame_desc[i].offset = total_bytes_for_urb;
+			urb->iso_frame_desc[i].length = bytes_for_packet;
+			total_bytes_for_urb += bytes_for_packet;
+		}
+		urb->transfer_buffer_length = total_bytes_for_urb;
+
+		offset_frames = tascam->driver_playback_pos;
+		frames_to_copy = bytes_to_frames(runtime, total_bytes_for_urb);
+		tascam->driver_playback_pos =
+			(offset_frames + frames_to_copy) % runtime->buffer_size;
+	}
+
+	if (total_bytes_for_urb > 0) {
+		u8 *dst_buf = urb->transfer_buffer;
+
+		/* Handle ring buffer wrap-around */
+		if (offset_frames + frames_to_copy > runtime->buffer_size) {
+			size_t first_chunk_bytes = frames_to_bytes(
+				runtime, runtime->buffer_size - offset_frames);
+			size_t second_chunk_bytes =
+				total_bytes_for_urb - first_chunk_bytes;
+
+			memcpy(dst_buf,
+			       runtime->dma_area +
+				       frames_to_bytes(runtime, offset_frames),
+			       first_chunk_bytes);
+			memcpy(dst_buf + first_chunk_bytes, runtime->dma_area,
+			       second_chunk_bytes);
+		} else {
+			memcpy(dst_buf,
+			       runtime->dma_area +
+				       frames_to_bytes(runtime, offset_frames),
+			       total_bytes_for_urb);
+		}
+
+		process_playback_routing_us144mkii(tascam, dst_buf, dst_buf,
+						   frames_to_copy);
+	}
+
+	urb->dev = tascam->dev;
+	usb_get_urb(urb);
+	usb_anchor_urb(urb, &tascam->playback_anchor);
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret < 0) {
+		dev_err_ratelimited(tascam->card->dev,
+				    "Failed to resubmit playback URB: %d\n",
+				    ret);
+		usb_unanchor_urb(urb);
+		usb_put_urb(urb);
+		atomic_dec(
+			&tascam->active_urbs); /* Decrement on failed resubmission */
+	}
+out:
+	usb_put_urb(urb);
+}
+
+void feedback_urb_complete(struct urb *urb)
+{
+	struct tascam_card *tascam = urb->context;
+	struct snd_pcm_substream *playback_ss, *capture_ss;
+	struct snd_pcm_runtime *playback_rt, *capture_rt;
+	u64 total_frames_in_urb = 0;
+	int ret, p;
+	unsigned int old_in_idx, new_in_idx;
+	bool playback_period_elapsed = false;
+	bool capture_period_elapsed = false;
+
+	if (urb->status) {
+		if (urb->status != -ENOENT && urb->status != -ECONNRESET &&
+		    urb->status != -ESHUTDOWN && urb->status != -ENODEV) {
+			dev_err_ratelimited(tascam->card->dev,
+					    "Feedback URB failed: %d\n",
+					    urb->status);
+			atomic_dec(
+				&tascam->active_urbs); /* Decrement on failed resubmission */
+		}
+		goto out;
+	}
+	if (!tascam || !atomic_read(&tascam->playback_active))
+		goto out;
+
+	playback_ss = tascam->playback_substream;
+	if (!playback_ss || !playback_ss->runtime)
+		goto out;
+	playback_rt = playback_ss->runtime;
+
+	capture_ss = tascam->capture_substream;
+	capture_rt = capture_ss ? capture_ss->runtime : NULL;
+
+	scoped_guard(spinlock_irqsave, &tascam->lock) {
+		if (tascam->feedback_urb_skip_count > 0) {
+			tascam->feedback_urb_skip_count--;
+			break;
+		}
+
+		old_in_idx = tascam->feedback_pattern_in_idx;
+
+		for (p = 0; p < urb->number_of_packets; p++) {
+			u8 feedback_value = 0;
+			const unsigned int *pattern;
+			bool packet_ok =
+				(urb->iso_frame_desc[p].status == 0 &&
+				 urb->iso_frame_desc[p].actual_length >= 1);
+
+			if (packet_ok)
+				feedback_value =
+					*((u8 *)urb->transfer_buffer +
+					  urb->iso_frame_desc[p].offset);
+
+			if (packet_ok) {
+				int delta = feedback_value -
+						    tascam->fpo.base_feedback_value +
+						    tascam->fpo.feedback_offset;
+				int pattern_idx;
+
+				if (delta < 0) {
+					pattern_idx =
+						0; // Clamp to the lowest pattern
+				} else if (delta >= 5) {
+					pattern_idx =
+						4; // Clamp to the highest pattern
+				} else {
+					pattern_idx = delta;
+				}
+
+				pattern =
+					tascam->fpo
+						.full_frame_patterns[pattern_idx];
+				tascam->feedback_consecutive_errors = 0;
+				int i;
+
+				for (i = 0; i < 8; i++) {
+					unsigned int in_idx =
+						(tascam->feedback_pattern_in_idx +
+						 i) %
+						FEEDBACK_ACCUMULATOR_SIZE;
+
+					tascam->feedback_accumulator_pattern
+						[in_idx] = pattern[i];
+					total_frames_in_urb += pattern[i];
+				}
+			} else {
+				unsigned int nominal_frames =
+					playback_rt->rate / 8000;
+				int i;
+
+				if (tascam->feedback_synced) {
+					tascam->feedback_consecutive_errors++;
+					if (tascam->feedback_consecutive_errors >
+					    FEEDBACK_SYNC_LOSS_THRESHOLD) {
+						dev_err(tascam->card->dev,
+							"Fatal: Feedback sync lost. Stopping stream.\n");
+						schedule_work(
+								&tascam->stop_pcm_work);
+						tascam->feedback_synced = false;
+						break;
+					}
+				}
+				for (i = 0; i < 8; i++) {
+					unsigned int in_idx =
+						(tascam->feedback_pattern_in_idx +
+						 i) %
+						FEEDBACK_ACCUMULATOR_SIZE;
+
+					tascam->feedback_accumulator_pattern
+						[in_idx] = nominal_frames;
+					total_frames_in_urb += nominal_frames;
+				}
+			}
+			tascam->feedback_pattern_in_idx =
+				(tascam->feedback_pattern_in_idx + 8) %
+				FEEDBACK_ACCUMULATOR_SIZE;
+		}
+
+		new_in_idx = tascam->feedback_pattern_in_idx;
+
+		if (!tascam->feedback_synced) {
+			unsigned int out_idx = tascam->feedback_pattern_out_idx;
+			bool is_ahead = (new_in_idx - out_idx) %
+						FEEDBACK_ACCUMULATOR_SIZE <
+					(FEEDBACK_ACCUMULATOR_SIZE / 2);
+			bool was_behind = (old_in_idx - out_idx) %
+						FEEDBACK_ACCUMULATOR_SIZE >=
+					(FEEDBACK_ACCUMULATOR_SIZE / 2);
+
+			if (is_ahead && was_behind) {
+				dev_dbg(tascam->card->dev,
+					"Sync Acquired! (in: %u, out: %u)\n",
+					new_in_idx, out_idx);
+				tascam->feedback_synced = true;
+				tascam->feedback_consecutive_errors = 0;
+			}
+		}
+
+		if (total_frames_in_urb > 0) {
+			tascam->playback_frames_consumed += total_frames_in_urb;
+			if (atomic_read(&tascam->capture_active))
+				tascam->capture_frames_processed +=
+					total_frames_in_urb;
+		}
+
+		if (playback_rt->period_size > 0) {
+			u64 current_period =
+				div_u64(tascam->playback_frames_consumed,
+						playback_rt->period_size);
+
+			if (current_period > tascam->last_period_pos) {
+				tascam->last_period_pos = current_period;
+				playback_period_elapsed = true;
+			}
+		}
+
+		if (atomic_read(&tascam->capture_active) && capture_rt &&
+		    capture_rt->period_size > 0) {
+			u64 current_capture_period =
+				div_u64(tascam->capture_frames_processed,
+						capture_rt->period_size);
+
+			if (current_capture_period >
+			    tascam->last_capture_period_pos) {
+				tascam->last_capture_period_pos =
+					current_capture_period;
+				capture_period_elapsed = true;
+			}
+		}
+	}
+	if (playback_period_elapsed)
+		snd_pcm_period_elapsed(playback_ss);
+	if (capture_period_elapsed)
+		snd_pcm_period_elapsed(capture_ss);
+
+	urb->dev = tascam->dev;
+	usb_get_urb(urb);
+	usb_anchor_urb(urb, &tascam->feedback_anchor);
+	ret = usb_submit_urb(urb, GFP_ATOMIC);
+	if (ret < 0) {
+		dev_err_ratelimited(tascam->card->dev,
+				    "Failed to resubmit feedback URB: %d\n",
+				    ret);
+		usb_unanchor_urb(urb);
+		usb_put_urb(urb);
+	}
+out:
+	usb_put_urb(urb);
+}
+
+void tascam_stop_pcm_work_handler(struct work_struct *work)
+{
+	struct tascam_card *tascam =
+		container_of(work, struct tascam_card, stop_pcm_work);
+
+	if (tascam->playback_substream)
+		snd_pcm_stop(tascam->playback_substream, SNDRV_PCM_STATE_XRUN);
+	if (tascam->capture_substream)
+		snd_pcm_stop(tascam->capture_substream, SNDRV_PCM_STATE_XRUN);
+}
diff --git a/sound/usb/usx2y/usX2Yhwdep.c b/sound/usb/usx2y/usX2Yhwdep.c
new file mode 100644
index 000000000..7f153a2fc
--- /dev/null
+++ b/sound/usb/usx2y/usX2Yhwdep.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Tascam US-X2Y USB soundcards
+ *
+ * FPGA Loader + ALSA Startup
+ *
+ * Copyright (c) 2003 by Karsten Wiese <annabellesgarden@yahoo.de>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <sound/core.h>
+#include <sound/memalloc.h>
+#include <sound/pcm.h>
+#include <sound/hwdep.h>
+#include "usx2y.h"
+#include "usbusx2y.h"
+#include "usX2Yhwdep.h"
+
+static vm_fault_t snd_us428ctls_vm_fault(struct vm_fault *vmf)
+{
+	unsigned long offset;
+	struct page *page;
+	void *vaddr;
+
+	offset = vmf->pgoff << PAGE_SHIFT;
+	if (offset >= US428_SHAREDMEM_PAGES)
+		return VM_FAULT_SIGBUS;
+	vaddr = (char *)((struct usx2ydev *)vmf->vma->vm_private_data)->us428ctls_sharedmem + offset;
+	page = virt_to_page(vaddr);
+	get_page(page);
+	vmf->page = page;
+
+	return 0;
+}
+
+static const struct vm_operations_struct us428ctls_vm_ops = {
+	.fault = snd_us428ctls_vm_fault,
+};
+
+static int snd_us428ctls_mmap(struct snd_hwdep *hw, struct file *filp, struct vm_area_struct *area)
+{
+	unsigned long	size = (unsigned long)(area->vm_end - area->vm_start);
+	struct usx2ydev	*us428 = hw->private_data;
+
+	// FIXME this hwdep interface is used twice: fpga download and mmap for controlling Lights etc. Maybe better using 2 hwdep devs?
+	// so as long as the device isn't fully initialised yet we return -EBUSY here.
+	if (!(us428->chip_status & USX2Y_STAT_CHIP_INIT))
+		return -EBUSY;
+
+	/* if userspace tries to mmap beyond end of our buffer, fail */
+	if (size > US428_SHAREDMEM_PAGES) {
+		dev_dbg(hw->card->dev, "%s: mmap size %lu > %lu\n", __func__,
+			size, (unsigned long)US428_SHAREDMEM_PAGES);
+		return -EINVAL;
+	}
+
+	area->vm_ops = &us428ctls_vm_ops;
+	vm_flags_set(area, VM_DONTEXPAND | VM_DONTDUMP);
+	area->vm_private_data = hw->private_data;
+	return 0;
+}
+
+static __poll_t snd_us428ctls_poll(struct snd_hwdep *hw, struct file *file, poll_table *wait)
+{
+	__poll_t	mask = 0;
+	struct usx2ydev	*us428 = hw->private_data;
+	struct us428ctls_sharedmem *shm = us428->us428ctls_sharedmem;
+
+	if (us428->chip_status & USX2Y_STAT_CHIP_HUP)
+		return EPOLLHUP;
+
+	poll_wait(file, &us428->us428ctls_wait_queue_head, wait);
+
+	if (shm && shm->ctl_snapshot_last != shm->ctl_snapshot_red)
+		mask |= EPOLLIN;
+
+	return mask;
+}
+
+
+static int snd_usx2y_hwdep_dsp_status(struct snd_hwdep *hw,
+				      struct snd_hwdep_dsp_status *info)
+{
+	static const char * const type_ids[USX2Y_TYPE_NUMS] = {
+		[USX2Y_TYPE_122] = "us122",
+		[USX2Y_TYPE_224] = "us224",
+		[USX2Y_TYPE_428] = "us428",
+	};
+	struct usx2ydev	*us428 = hw->private_data;
+	int id = -1;
+
+	switch (le16_to_cpu(us428->dev->descriptor.idProduct)) {
+	case USB_ID_US122:
+		id = USX2Y_TYPE_122;
+		break;
+	case USB_ID_US224:
+		id = USX2Y_TYPE_224;
+		break;
+	case USB_ID_US428:
+		id = USX2Y_TYPE_428;
+		break;
+	}
+	if (id < 0)
+		return -ENODEV;
+	strscpy(info->id, type_ids[id]);
+	info->num_dsps = 2;		// 0: Prepad Data, 1: FPGA Code
+	if (us428->chip_status & USX2Y_STAT_CHIP_INIT)
+		info->chip_ready = 1;
+	info->version = USX2Y_DRIVER_VERSION;
+	return 0;
+}
+
+static int usx2y_create_usbmidi(struct snd_card *card)
+{
+	static const struct snd_usb_midi_endpoint_info quirk_data_1 = {
+		.out_ep = 0x06,
+		.in_ep = 0x06,
+		.out_cables =	0x001,
+		.in_cables =	0x001
+	};
+	static const struct snd_usb_audio_quirk quirk_1 = {
+		.vendor_name =	"TASCAM",
+		.product_name =	NAME_ALLCAPS,
+		.ifnum =	0,
+		.type = QUIRK_MIDI_FIXED_ENDPOINT,
+		.data = &quirk_data_1
+	};
+	static const struct snd_usb_midi_endpoint_info quirk_data_2 = {
+		.out_ep = 0x06,
+		.in_ep = 0x06,
+		.out_cables =	0x003,
+		.in_cables =	0x003
+	};
+	static const struct snd_usb_audio_quirk quirk_2 = {
+		.vendor_name =	"TASCAM",
+		.product_name =	"US428",
+		.ifnum =	0,
+		.type = QUIRK_MIDI_FIXED_ENDPOINT,
+		.data = &quirk_data_2
+	};
+	struct usb_device *dev = usx2y(card)->dev;
+	struct usb_interface *iface = usb_ifnum_to_if(dev, 0);
+	const struct snd_usb_audio_quirk *quirk =
+		le16_to_cpu(dev->descriptor.idProduct) == USB_ID_US428 ?
+		&quirk_2 : &quirk_1;
+
+	return snd_usbmidi_create(card, iface, &usx2y(card)->midi_list, quirk);
+}
+
+static int usx2y_create_alsa_devices(struct snd_card *card)
+{
+	int err;
+
+	err = usx2y_create_usbmidi(card);
+	if (err < 0) {
+		dev_err(card->dev, "%s: usx2y_create_usbmidi error %i\n",
+			__func__, err);
+		return err;
+	}
+	err = usx2y_audio_create(card);
+	if (err < 0)
+		return err;
+	err = usx2y_hwdep_pcm_new(card);
+	if (err < 0)
+		return err;
+	err = snd_card_register(card);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+static int snd_usx2y_hwdep_dsp_load(struct snd_hwdep *hw,
+				    struct snd_hwdep_dsp_image *dsp)
+{
+	struct usx2ydev *priv = hw->private_data;
+	struct usb_device *dev = priv->dev;
+	int lret, err;
+	char *buf;
+
+	buf = memdup_user(dsp->image, dsp->length);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	err = usb_set_interface(dev, 0, 1);
+	if (err)
+		dev_err(&dev->dev, "usb_set_interface error\n");
+	else
+		err = usb_bulk_msg(dev, usb_sndbulkpipe(dev, 2), buf, dsp->length, &lret, 6000);
+	kfree(buf);
+	if (err)
+		return err;
+	if (dsp->index == 1) {
+		msleep(250);				// give the device some time
+		err = usx2y_async_seq04_init(priv);
+		if (err) {
+			dev_err(&dev->dev, "usx2y_async_seq04_init error\n");
+			return err;
+		}
+		err = usx2y_in04_init(priv);
+		if (err) {
+			dev_err(&dev->dev, "usx2y_in04_init error\n");
+			return err;
+		}
+		err = usx2y_create_alsa_devices(hw->card);
+		if (err) {
+			dev_err(&dev->dev, "usx2y_create_alsa_devices error %i\n", err);
+			return err;
+		}
+		priv->chip_status |= USX2Y_STAT_CHIP_INIT;
+	}
+	return err;
+}
+
+int usx2y_hwdep_new(struct snd_card *card, struct usb_device *device)
+{
+	int err;
+	struct snd_hwdep *hw;
+	struct usx2ydev	*us428 = usx2y(card);
+
+	err = snd_hwdep_new(card, SND_USX2Y_LOADER_ID, 0, &hw);
+	if (err < 0)
+		return err;
+
+	hw->iface = SNDRV_HWDEP_IFACE_USX2Y;
+	hw->private_data = us428;
+	hw->ops.dsp_status = snd_usx2y_hwdep_dsp_status;
+	hw->ops.dsp_load = snd_usx2y_hwdep_dsp_load;
+	hw->ops.mmap = snd_us428ctls_mmap;
+	hw->ops.poll = snd_us428ctls_poll;
+	hw->exclusive = 1;
+	sprintf(hw->name, "/dev/bus/usb/%03d/%03d", device->bus->busnum, device->devnum);
+
+	us428->us428ctls_sharedmem = alloc_pages_exact(US428_SHAREDMEM_PAGES, GFP_KERNEL);
+	if (!us428->us428ctls_sharedmem)
+		return -ENOMEM;
+	memset(us428->us428ctls_sharedmem, -1, US428_SHAREDMEM_PAGES);
+	us428->us428ctls_sharedmem->ctl_snapshot_last = -2;
+
+	return 0;
+}
diff --git a/sound/usb/usx2y/usX2Yhwdep.h b/sound/usb/usx2y/usX2Yhwdep.h
new file mode 100644
index 000000000..0c9946d9c
--- /dev/null
+++ b/sound/usb/usx2y/usX2Yhwdep.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef USX2YHWDEP_H
+#define USX2YHWDEP_H
+
+int usx2y_hwdep_new(struct snd_card *card, struct usb_device *device);
+
+#endif
diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c
new file mode 100644
index 000000000..3122cf653
--- /dev/null
+++ b/sound/usb/usx2y/usb_stream.c
@@ -0,0 +1,775 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2007, 2008 Karsten Wiese <fzu@wemgehoertderstaat.de>
+ */
+
+#include <linux/usb.h>
+#include <linux/gfp.h>
+
+#include "usb_stream.h"
+
+/*                             setup                                  */
+
+static unsigned int usb_stream_next_packet_size(struct usb_stream_kernel *sk)
+{
+	struct usb_stream *s = sk->s;
+
+	sk->out_phase_peeked = (sk->out_phase & 0xffff) + sk->freqn;
+	return (sk->out_phase_peeked >> 16) * s->cfg.frame_size;
+}
+
+static void playback_prep_freqn(struct usb_stream_kernel *sk, struct urb *urb)
+{
+	struct usb_stream *s = sk->s;
+	int pack, lb = 0;
+
+	for (pack = 0; pack < sk->n_o_ps; pack++) {
+		int l = usb_stream_next_packet_size(sk);
+
+		if (s->idle_outsize + lb + l > s->period_size)
+			goto check;
+
+		sk->out_phase = sk->out_phase_peeked;
+		urb->iso_frame_desc[pack].offset = lb;
+		urb->iso_frame_desc[pack].length = l;
+		lb += l;
+	}
+
+check:
+	urb->number_of_packets = pack;
+	urb->transfer_buffer_length = lb;
+	s->idle_outsize += lb - s->period_size;
+}
+
+static int init_pipe_urbs(struct usb_stream_kernel *sk,
+			  unsigned int use_packsize,
+			  struct urb **urbs, char *transfer,
+			  struct usb_device *dev, int pipe)
+{
+	int u, p;
+	int maxpacket = use_packsize ?
+		use_packsize : usb_maxpacket(dev, pipe);
+	int transfer_length = maxpacket * sk->n_o_ps;
+
+	for (u = 0; u < USB_STREAM_NURBS;
+	     ++u, transfer += transfer_length) {
+		struct urb *urb = urbs[u];
+		struct usb_iso_packet_descriptor *desc;
+
+		urb->transfer_buffer = transfer;
+		urb->dev = dev;
+		urb->pipe = pipe;
+		urb->number_of_packets = sk->n_o_ps;
+		urb->context = sk;
+		urb->interval = 1;
+		if (usb_pipeout(pipe))
+			continue;
+		if (usb_urb_ep_type_check(urb))
+			return -EINVAL;
+
+		urb->transfer_buffer_length = transfer_length;
+		desc = urb->iso_frame_desc;
+		desc->offset = 0;
+		desc->length = maxpacket;
+		for (p = 1; p < sk->n_o_ps; ++p) {
+			desc[p].offset = desc[p - 1].offset + maxpacket;
+			desc[p].length = maxpacket;
+		}
+	}
+
+	return 0;
+}
+
+static int init_urbs(struct usb_stream_kernel *sk, unsigned int use_packsize,
+		     struct usb_device *dev, int in_pipe, int out_pipe)
+{
+	struct usb_stream	*s = sk->s;
+	char			*indata =
+		(char *)s + sizeof(*s) + sizeof(struct usb_stream_packet) * s->inpackets;
+	int			u;
+
+	for (u = 0; u < USB_STREAM_NURBS; ++u) {
+		sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
+		if (!sk->inurb[u])
+			return -ENOMEM;
+
+		sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
+		if (!sk->outurb[u])
+			return -ENOMEM;
+	}
+
+	if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
+	    init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
+			   out_pipe))
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
+ * this will overflow at approx 524 kHz
+ */
+static inline unsigned int get_usb_full_speed_rate(unsigned int rate)
+{
+	return ((rate << 13) + 62) / 125;
+}
+
+/*
+ * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
+ * this will overflow at approx 4 MHz
+ */
+static inline unsigned int get_usb_high_speed_rate(unsigned int rate)
+{
+	return ((rate << 10) + 62) / 125;
+}
+
+void usb_stream_free(struct usb_stream_kernel *sk)
+{
+	struct usb_stream *s;
+	unsigned int u;
+
+	for (u = 0; u < USB_STREAM_NURBS; ++u) {
+		usb_free_urb(sk->inurb[u]);
+		sk->inurb[u] = NULL;
+		usb_free_urb(sk->outurb[u]);
+		sk->outurb[u] = NULL;
+	}
+
+	s = sk->s;
+	if (!s)
+		return;
+
+	if (sk->write_page) {
+		free_pages_exact(sk->write_page, s->write_size);
+		sk->write_page = NULL;
+	}
+
+	free_pages_exact(s, s->read_size);
+	sk->s = NULL;
+}
+
+struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
+				  struct usb_device *dev,
+				  unsigned int in_endpoint,
+				  unsigned int out_endpoint,
+				  unsigned int sample_rate,
+				  unsigned int use_packsize,
+				  unsigned int period_frames,
+				  unsigned int frame_size)
+{
+	int packets, max_packsize;
+	int in_pipe, out_pipe;
+	int read_size = sizeof(struct usb_stream);
+	int write_size;
+	int usb_frames = dev->speed == USB_SPEED_HIGH ? 8000 : 1000;
+
+	in_pipe = usb_rcvisocpipe(dev, in_endpoint);
+	out_pipe = usb_sndisocpipe(dev, out_endpoint);
+
+	max_packsize = use_packsize ?
+		use_packsize : usb_maxpacket(dev, in_pipe);
+
+	/*
+		t_period = period_frames / sample_rate
+		iso_packs = t_period / t_iso_frame
+			= (period_frames / sample_rate) * (1 / t_iso_frame)
+	*/
+
+	packets = period_frames * usb_frames / sample_rate + 1;
+
+	if (dev->speed == USB_SPEED_HIGH)
+		packets = (packets + 7) & ~7;
+
+	read_size += packets * USB_STREAM_URBDEPTH *
+		(max_packsize + sizeof(struct usb_stream_packet));
+
+	max_packsize = usb_maxpacket(dev, out_pipe);
+	write_size = max_packsize * packets * USB_STREAM_URBDEPTH;
+
+	if (read_size >= 256*PAGE_SIZE || write_size >= 256*PAGE_SIZE) {
+		dev_warn(&dev->dev, "%s: a size exceeds 128*PAGE_SIZE\n", __func__);
+		goto out;
+	}
+
+	sk->s = alloc_pages_exact(read_size,
+				  GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
+	if (!sk->s) {
+		dev_warn(&dev->dev, "us122l: couldn't allocate read buffer\n");
+		goto out;
+	}
+	sk->s->cfg.version = USB_STREAM_INTERFACE_VERSION;
+
+	sk->s->read_size = read_size;
+
+	sk->s->cfg.sample_rate = sample_rate;
+	sk->s->cfg.frame_size = frame_size;
+	sk->n_o_ps = packets;
+	sk->s->inpackets = packets * USB_STREAM_URBDEPTH;
+	sk->s->cfg.period_frames = period_frames;
+	sk->s->period_size = frame_size * period_frames;
+
+	sk->s->write_size = write_size;
+
+	sk->write_page = alloc_pages_exact(write_size,
+					   GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
+	if (!sk->write_page) {
+		dev_warn(&dev->dev, "us122l: couldn't allocate write buffer\n");
+		usb_stream_free(sk);
+		return NULL;
+	}
+
+	/* calculate the frequency in 16.16 format */
+	if (dev->speed == USB_SPEED_FULL)
+		sk->freqn = get_usb_full_speed_rate(sample_rate);
+	else
+		sk->freqn = get_usb_high_speed_rate(sample_rate);
+
+	if (init_urbs(sk, use_packsize, dev, in_pipe, out_pipe) < 0) {
+		usb_stream_free(sk);
+		return NULL;
+	}
+
+	sk->s->state = usb_stream_stopped;
+out:
+	return sk->s;
+}
+
+/*                             start                                  */
+
+static bool balance_check(struct usb_stream_kernel *sk, struct urb *urb)
+{
+	bool r;
+
+	if (unlikely(urb->status)) {
+		if (urb->status != -ESHUTDOWN && urb->status != -ENOENT)
+			dev_warn(&sk->dev->dev, "%s: status=%i\n", __func__,
+				 urb->status);
+		sk->iso_frame_balance = 0x7FFFFFFF;
+		return false;
+	}
+	r = sk->iso_frame_balance == 0;
+	if (!r)
+		sk->i_urb = urb;
+	return r;
+}
+
+static bool balance_playback(struct usb_stream_kernel *sk, struct urb *urb)
+{
+	sk->iso_frame_balance += urb->number_of_packets;
+	return balance_check(sk, urb);
+}
+
+static bool balance_capture(struct usb_stream_kernel *sk, struct urb *urb)
+{
+	sk->iso_frame_balance -= urb->number_of_packets;
+	return balance_check(sk, urb);
+}
+
+static void subs_set_complete(struct urb **urbs, void (*complete)(struct urb *))
+{
+	int u;
+
+	for (u = 0; u < USB_STREAM_NURBS; u++) {
+		struct urb *urb = urbs[u];
+
+		urb->complete = complete;
+	}
+}
+
+static int usb_stream_prepare_playback(struct usb_stream_kernel *sk,
+		struct urb *inurb)
+{
+	struct usb_stream *s = sk->s;
+	struct urb *io;
+	struct usb_iso_packet_descriptor *id, *od;
+	int p = 0, lb = 0, l = 0;
+
+	io = sk->idle_outurb;
+	od = io->iso_frame_desc;
+
+	for (; s->sync_packet < 0; ++p, ++s->sync_packet) {
+		struct urb *ii = sk->completed_inurb;
+
+		id = ii->iso_frame_desc +
+			ii->number_of_packets + s->sync_packet;
+		l = id->actual_length;
+
+		od[p].length = l;
+		od[p].offset = lb;
+		lb += l;
+	}
+
+	for (;
+	     s->sync_packet < inurb->number_of_packets && p < sk->n_o_ps;
+	     ++p, ++s->sync_packet) {
+		l = inurb->iso_frame_desc[s->sync_packet].actual_length;
+
+		if (s->idle_outsize + lb + l > s->period_size)
+			goto check_ok;
+
+		od[p].length = l;
+		od[p].offset = lb;
+		lb += l;
+	}
+
+check_ok:
+	s->sync_packet -= inurb->number_of_packets;
+	if (unlikely(s->sync_packet < -2 || s->sync_packet > 0)) {
+		dev_warn(&sk->dev->dev,
+			 "%s: invalid sync_packet = %i; p=%i nop=%i %i %x %x %x > %x\n",
+			 __func__,
+			 s->sync_packet, p, inurb->number_of_packets,
+			 s->idle_outsize + lb + l,
+			 s->idle_outsize, lb,  l,
+			 s->period_size);
+		return -1;
+	}
+	if (unlikely(lb % s->cfg.frame_size)) {
+		dev_warn(&sk->dev->dev, "%s: invalid outsize = %i\n",
+			 __func__, lb);
+		return -1;
+	}
+	s->idle_outsize += lb - s->period_size;
+	io->number_of_packets = p;
+	io->transfer_buffer_length = lb;
+	if (s->idle_outsize <= 0)
+		return 0;
+
+	dev_warn(&sk->dev->dev, "%s: idle=%i\n", __func__, s->idle_outsize);
+	return -1;
+}
+
+static void prepare_inurb(int number_of_packets, struct urb *iu)
+{
+	struct usb_iso_packet_descriptor *id;
+	int p;
+
+	iu->number_of_packets = number_of_packets;
+	id = iu->iso_frame_desc;
+	id->offset = 0;
+	for (p = 0; p < iu->number_of_packets - 1; ++p)
+		id[p + 1].offset = id[p].offset + id[p].length;
+
+	iu->transfer_buffer_length =
+		id[0].length * iu->number_of_packets;
+}
+
+static int submit_urbs(struct usb_stream_kernel *sk,
+		       struct urb *inurb, struct urb *outurb)
+{
+	int err;
+
+	prepare_inurb(sk->idle_outurb->number_of_packets, sk->idle_inurb);
+	err = usb_submit_urb(sk->idle_inurb, GFP_ATOMIC);
+	if (err < 0)
+		goto report_failure;
+
+	sk->idle_inurb = sk->completed_inurb;
+	sk->completed_inurb = inurb;
+	err = usb_submit_urb(sk->idle_outurb, GFP_ATOMIC);
+	if (err < 0)
+		goto report_failure;
+
+	sk->idle_outurb = sk->completed_outurb;
+	sk->completed_outurb = outurb;
+	return 0;
+
+report_failure:
+	dev_err(&sk->dev->dev, "%s error: %i\n", __func__, err);
+	return err;
+}
+
+#ifdef DEBUG_LOOP_BACK
+/*
+  This loop_back() shows how to read/write the period data.
+ */
+static void loop_back(struct usb_stream *s)
+{
+	char *i, *o;
+	int il, ol, l, p;
+	struct urb *iu;
+	struct usb_iso_packet_descriptor *id;
+
+	o = s->playback1st_to;
+	ol = s->playback1st_size;
+	l = 0;
+
+	if (s->insplit_pack >= 0) {
+		iu = sk->idle_inurb;
+		id = iu->iso_frame_desc;
+		p = s->insplit_pack;
+	} else
+		goto second;
+loop:
+	for (; p < iu->number_of_packets && l < s->period_size; ++p) {
+		i = iu->transfer_buffer + id[p].offset;
+		il = id[p].actual_length;
+		if (l + il > s->period_size)
+			il = s->period_size - l;
+		if (il <= ol) {
+			memcpy(o, i, il);
+			o += il;
+			ol -= il;
+		} else {
+			memcpy(o, i, ol);
+			singen_6pack(o, ol);
+			o = s->playback_to;
+			memcpy(o, i + ol, il - ol);
+			o += il - ol;
+			ol = s->period_size - s->playback1st_size;
+		}
+		l += il;
+	}
+	if (iu == sk->completed_inurb) {
+		if (l != s->period_size)
+			dev_dbg(&sk->dev->dev, "%s:%i %i\n", __func__, __LINE__,
+				l/(int)s->cfg.frame_size);
+
+		return;
+	}
+second:
+	iu = sk->completed_inurb;
+	id = iu->iso_frame_desc;
+	p = 0;
+	goto loop;
+
+}
+#else
+static void loop_back(struct usb_stream *s)
+{
+}
+#endif
+
+static void stream_idle(struct usb_stream_kernel *sk,
+			struct urb *inurb, struct urb *outurb)
+{
+	struct usb_stream *s = sk->s;
+	int l, p;
+	int insize = s->idle_insize;
+	int urb_size = 0;
+
+	s->inpacket_split = s->next_inpacket_split;
+	s->inpacket_split_at = s->next_inpacket_split_at;
+	s->next_inpacket_split = -1;
+	s->next_inpacket_split_at = 0;
+
+	for (p = 0; p < inurb->number_of_packets; ++p) {
+		struct usb_iso_packet_descriptor *id = inurb->iso_frame_desc;
+
+		l = id[p].actual_length;
+		if (unlikely(l == 0 || id[p].status)) {
+			dev_warn(&sk->dev->dev, "%s: underrun, status=%u\n",
+				 __func__, id[p].status);
+			goto err_out;
+		}
+		s->inpacket_head++;
+		s->inpacket_head %= s->inpackets;
+		if (s->inpacket_split == -1)
+			s->inpacket_split = s->inpacket_head;
+
+		s->inpacket[s->inpacket_head].offset =
+			id[p].offset + (inurb->transfer_buffer - (void *)s);
+		s->inpacket[s->inpacket_head].length = l;
+		if (insize + l > s->period_size &&
+		    s->next_inpacket_split == -1) {
+			s->next_inpacket_split = s->inpacket_head;
+			s->next_inpacket_split_at = s->period_size - insize;
+		}
+		insize += l;
+		urb_size += l;
+	}
+	s->idle_insize += urb_size - s->period_size;
+	if (s->idle_insize < 0) {
+		dev_warn(&sk->dev->dev, "%s error: %i\n", __func__,
+			 (s->idle_insize)/(int)s->cfg.frame_size);
+		goto err_out;
+	}
+	s->insize_done += urb_size;
+
+	l = s->idle_outsize;
+	s->outpacket[0].offset = (sk->idle_outurb->transfer_buffer -
+				  sk->write_page) - l;
+
+	if (usb_stream_prepare_playback(sk, inurb) < 0)
+		goto err_out;
+
+	s->outpacket[0].length = sk->idle_outurb->transfer_buffer_length + l;
+	s->outpacket[1].offset = sk->completed_outurb->transfer_buffer -
+		sk->write_page;
+
+	if (submit_urbs(sk, inurb, outurb) < 0)
+		goto err_out;
+
+	loop_back(s);
+	s->periods_done++;
+	wake_up_all(&sk->sleep);
+	return;
+err_out:
+	s->state = usb_stream_xrun;
+	wake_up_all(&sk->sleep);
+}
+
+static void i_capture_idle(struct urb *urb)
+{
+	struct usb_stream_kernel *sk = urb->context;
+
+	if (balance_capture(sk, urb))
+		stream_idle(sk, urb, sk->i_urb);
+}
+
+static void i_playback_idle(struct urb *urb)
+{
+	struct usb_stream_kernel *sk = urb->context;
+
+	if (balance_playback(sk, urb))
+		stream_idle(sk, sk->i_urb, urb);
+}
+
+static void stream_start(struct usb_stream_kernel *sk,
+			 struct urb *inurb, struct urb *outurb)
+{
+	struct usb_stream *s = sk->s;
+
+	if (s->state >= usb_stream_sync1) {
+		int l, p, max_diff, max_diff_0;
+		int urb_size = 0;
+		unsigned int frames_per_packet, min_frames = 0;
+
+		frames_per_packet = (s->period_size - s->idle_insize);
+		frames_per_packet <<= 8;
+		frames_per_packet /=
+			s->cfg.frame_size * inurb->number_of_packets;
+		frames_per_packet++;
+
+		max_diff_0 = s->cfg.frame_size;
+		if (s->cfg.period_frames >= 256)
+			max_diff_0 <<= 1;
+		if (s->cfg.period_frames >= 1024)
+			max_diff_0 <<= 1;
+		max_diff = max_diff_0;
+		for (p = 0; p < inurb->number_of_packets; ++p) {
+			int diff;
+
+			l = inurb->iso_frame_desc[p].actual_length;
+			urb_size += l;
+
+			min_frames += frames_per_packet;
+			diff = urb_size -
+				(min_frames >> 8) * s->cfg.frame_size;
+			if (diff < max_diff)
+				max_diff = diff;
+		}
+		s->idle_insize -= max_diff - max_diff_0;
+		s->idle_insize += urb_size - s->period_size;
+		if (s->idle_insize < 0) {
+			dev_warn(&sk->dev->dev, "%s idle_insize: %i %i %i\n",
+				 __func__,
+				 s->idle_insize, urb_size, s->period_size);
+			return;
+		} else if (s->idle_insize == 0) {
+			s->next_inpacket_split =
+				(s->inpacket_head + 1) % s->inpackets;
+			s->next_inpacket_split_at = 0;
+		} else {
+			unsigned int split = s->inpacket_head;
+
+			l = s->idle_insize;
+			while (l > s->inpacket[split].length) {
+				l -= s->inpacket[split].length;
+				if (split == 0)
+					split = s->inpackets - 1;
+				else
+					split--;
+			}
+			s->next_inpacket_split = split;
+			s->next_inpacket_split_at =
+				s->inpacket[split].length - l;
+		}
+
+		s->insize_done += urb_size;
+
+		if (usb_stream_prepare_playback(sk, inurb) < 0)
+			return;
+
+	} else
+		playback_prep_freqn(sk, sk->idle_outurb);
+
+	if (submit_urbs(sk, inurb, outurb) < 0)
+		return;
+
+	if (s->state == usb_stream_sync1 && s->insize_done > 360000) {
+		/* just guesswork                            ^^^^^^ */
+		s->state = usb_stream_ready;
+		subs_set_complete(sk->inurb, i_capture_idle);
+		subs_set_complete(sk->outurb, i_playback_idle);
+	}
+}
+
+static void i_capture_start(struct urb *urb)
+{
+	struct usb_iso_packet_descriptor *id = urb->iso_frame_desc;
+	struct usb_stream_kernel *sk = urb->context;
+	struct usb_stream *s = sk->s;
+	int p;
+	int empty = 0;
+
+	if (urb->status) {
+		dev_warn(&sk->dev->dev, "%s: status=%i\n", __func__, urb->status);
+		return;
+	}
+
+	for (p = 0; p < urb->number_of_packets; ++p) {
+		int l = id[p].actual_length;
+
+		if (l < s->cfg.frame_size) {
+			++empty;
+			if (s->state >= usb_stream_sync0) {
+				dev_warn(&sk->dev->dev, "%s: length %i\n", __func__, l);
+				return;
+			}
+		}
+		s->inpacket_head++;
+		s->inpacket_head %= s->inpackets;
+		s->inpacket[s->inpacket_head].offset =
+			id[p].offset + (urb->transfer_buffer - (void *)s);
+		s->inpacket[s->inpacket_head].length = l;
+	}
+#ifdef SHOW_EMPTY
+	if (empty) {
+		dev_dbg(&sk->dev->dev, "%s:%i: %i", __func__, __LINE__,
+			urb->iso_frame_desc[0].actual_length);
+		for (pack = 1; pack < urb->number_of_packets; ++pack) {
+			int l = urb->iso_frame_desc[pack].actual_length;
+
+			printk(KERN_CONT " %i", l);
+		}
+		printk(KERN_CONT "\n");
+	}
+#endif
+	if (!empty && s->state < usb_stream_sync1)
+		++s->state;
+
+	if (balance_capture(sk, urb))
+		stream_start(sk, urb, sk->i_urb);
+}
+
+static void i_playback_start(struct urb *urb)
+{
+	struct usb_stream_kernel *sk = urb->context;
+
+	if (balance_playback(sk, urb))
+		stream_start(sk, sk->i_urb, urb);
+}
+
+int usb_stream_start(struct usb_stream_kernel *sk)
+{
+	struct usb_stream *s = sk->s;
+	int frame = 0;
+	int u, err;
+	int try = 0;
+
+	if (s->state != usb_stream_stopped)
+		return -EAGAIN;
+
+	subs_set_complete(sk->inurb, i_capture_start);
+	subs_set_complete(sk->outurb, i_playback_start);
+	memset(sk->write_page, 0, s->write_size);
+dotry:
+	s->insize_done = 0;
+	s->idle_insize = 0;
+	s->idle_outsize = 0;
+	s->sync_packet = -1;
+	s->inpacket_head = -1;
+	sk->iso_frame_balance = 0;
+	++try;
+	for (u = 0; u < 2; u++) {
+		struct urb *inurb = sk->inurb[u];
+		struct urb *outurb = sk->outurb[u];
+
+		playback_prep_freqn(sk, outurb);
+		inurb->number_of_packets = outurb->number_of_packets;
+		inurb->transfer_buffer_length =
+			inurb->number_of_packets *
+			inurb->iso_frame_desc[0].length;
+
+		if (u == 0) {
+			int now;
+			struct usb_device *dev = inurb->dev;
+
+			frame = usb_get_current_frame_number(dev);
+			do {
+				now = usb_get_current_frame_number(dev);
+			} while (now > -1 && now == frame);
+		}
+		err = usb_submit_urb(inurb, GFP_ATOMIC);
+		if (err < 0) {
+			dev_err(&sk->dev->dev,
+				"%s: usb_submit_urb(sk->inurb[%i]) returned %i\n",
+				__func__, u, err);
+			return err;
+		}
+		err = usb_submit_urb(outurb, GFP_ATOMIC);
+		if (err < 0) {
+			dev_err(&sk->dev->dev,
+				"%s: usb_submit_urb(sk->outurb[%i]) returned %i\n",
+				__func__, u, err);
+			return err;
+		}
+
+		if (inurb->start_frame != outurb->start_frame) {
+			dev_dbg(&sk->dev->dev,
+				"%s: u[%i] start_frames differ in:%u out:%u\n",
+				__func__, u, inurb->start_frame, outurb->start_frame);
+			goto check_retry;
+		}
+	}
+	try = 0;
+check_retry:
+	if (try) {
+		usb_stream_stop(sk);
+		if (try < 5) {
+			msleep(1500);
+			dev_dbg(&sk->dev->dev, "goto dotry;\n");
+			goto dotry;
+		}
+		dev_warn(&sk->dev->dev,
+			 "%s: couldn't start all urbs on the same start_frame.\n",
+			 __func__);
+		return -EFAULT;
+	}
+
+	sk->idle_inurb = sk->inurb[USB_STREAM_NURBS - 2];
+	sk->idle_outurb = sk->outurb[USB_STREAM_NURBS - 2];
+	sk->completed_inurb = sk->inurb[USB_STREAM_NURBS - 1];
+	sk->completed_outurb = sk->outurb[USB_STREAM_NURBS - 1];
+
+/* wait, check */
+	{
+		int wait_ms = 3000;
+
+		while (s->state != usb_stream_ready && wait_ms > 0) {
+			msleep(200);
+			wait_ms -= 200;
+		}
+	}
+
+	return s->state == usb_stream_ready ? 0 : -EFAULT;
+}
+
+
+/*                             stop                                   */
+
+void usb_stream_stop(struct usb_stream_kernel *sk)
+{
+	int u;
+
+	if (!sk->s)
+		return;
+	for (u = 0; u < USB_STREAM_NURBS; ++u) {
+		usb_kill_urb(sk->inurb[u]);
+		usb_kill_urb(sk->outurb[u]);
+	}
+	sk->s->state = usb_stream_stopped;
+	msleep(400);
+}
diff --git a/sound/usb/usx2y/usb_stream.h b/sound/usb/usx2y/usb_stream.h
new file mode 100644
index 000000000..2ed10add4
--- /dev/null
+++ b/sound/usb/usx2y/usb_stream.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __USB_STREAM_H
+#define __USB_STREAM_H
+
+#include <uapi/sound/usb_stream.h>
+
+#define USB_STREAM_NURBS 4
+#define USB_STREAM_URBDEPTH 4
+
+struct usb_stream_kernel {
+	struct usb_stream *s;
+	struct usb_device *dev;
+
+	void *write_page;
+
+	unsigned int n_o_ps;
+
+	struct urb *inurb[USB_STREAM_NURBS];
+	struct urb *idle_inurb;
+	struct urb *completed_inurb;
+	struct urb *outurb[USB_STREAM_NURBS];
+	struct urb *idle_outurb;
+	struct urb *completed_outurb;
+	struct urb *i_urb;
+
+	int iso_frame_balance;
+
+	wait_queue_head_t sleep;
+
+	unsigned int out_phase;
+	unsigned int out_phase_peeked;
+	unsigned int freqn;
+};
+
+struct usb_stream *usb_stream_new(struct usb_stream_kernel *sk,
+				  struct usb_device *dev,
+				  unsigned int in_endpoint,
+				  unsigned int out_endpoint,
+				  unsigned int sample_rate,
+				  unsigned int use_packsize,
+				  unsigned int period_frames,
+				  unsigned int frame_size);
+void usb_stream_free(struct usb_stream_kernel *sk);
+int usb_stream_start(struct usb_stream_kernel *sk);
+void usb_stream_stop(struct usb_stream_kernel *sk);
+
+#endif /* __USB_STREAM_H */
diff --git a/sound/usb/usx2y/usbus428ctldefs.h b/sound/usb/usx2y/usbus428ctldefs.h
new file mode 100644
index 000000000..9ba15d974
--- /dev/null
+++ b/sound/usb/usx2y/usbus428ctldefs.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *
+ * Copyright (c) 2003 by Karsten Wiese <annabellesgarden@yahoo.de>
+ */
+
+enum E_IN84 {
+	E_FADER_0 = 0,
+	E_FADER_1,
+	E_FADER_2,
+	E_FADER_3,
+	E_FADER_4,
+	E_FADER_5,
+	E_FADER_6,
+	E_FADER_7,
+	E_FADER_M,
+	E_TRANSPORT,
+	E_MODIFIER = 10,
+	E_FILTER_SELECT,
+	E_SELECT,
+	E_MUTE,
+
+	E_SWITCH   = 15,
+	E_WHEEL_GAIN,
+	E_WHEEL_FREQ,
+	E_WHEEL_Q,
+	E_WHEEL_PAN,
+	E_WHEEL    = 20
+};
+
+#define T_RECORD   1
+#define T_PLAY     2
+#define T_STOP     4
+#define T_F_FWD    8
+#define T_REW   0x10
+#define T_SOLO  0x20
+#define T_REC   0x40
+#define T_NULL  0x80
+
+
+struct us428_ctls {
+	unsigned char	fader[9];
+	unsigned char	transport;
+	unsigned char	modifier;
+	unsigned char	filters_elect;
+	unsigned char	select;
+	unsigned char	mute;
+	unsigned char	unknown;
+	unsigned char	wswitch;
+	unsigned char	wheel[5];
+};
+
+struct us428_set_byte {
+	unsigned char offset,
+		value;
+};
+
+enum {
+	ELT_VOLUME = 0,
+	ELT_LIGHT
+};
+
+struct usx2y_volume {
+	unsigned char channel,
+		lh,
+		ll,
+		rh,
+		rl;
+};
+
+struct us428_lights {
+	struct us428_set_byte light[7];
+};
+
+struct us428_p4out {
+	char type;
+	union {
+		struct usx2y_volume vol;
+		struct us428_lights lights;
+	} val;
+};
+
+#define N_US428_CTL_BUFS 16
+#define N_US428_P4OUT_BUFS 16
+struct us428ctls_sharedmem {
+	struct us428_ctls	ctl_snapshot[N_US428_CTL_BUFS];
+	int			ctl_snapshot_differs_at[N_US428_CTL_BUFS];
+	int			ctl_snapshot_last, ctl_snapshot_red;
+	struct us428_p4out	p4out[N_US428_P4OUT_BUFS];
+	int			p4out_last, p4out_sent;
+};
+
+#define US428_SHAREDMEM_PAGES	PAGE_ALIGN(sizeof(struct us428ctls_sharedmem))
diff --git a/sound/usb/usx2y/usbusx2y.c b/sound/usb/usx2y/usbusx2y.c
new file mode 100644
index 000000000..4190227c5
--- /dev/null
+++ b/sound/usb/usx2y/usbusx2y.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * usbusx2y.c - ALSA USB US-428 Driver
+ *
+2005-04-14 Karsten Wiese
+	Version 0.8.7.2:
+	Call snd_card_free() instead of snd_card_free_in_thread() to prevent oops with dead keyboard symptom.
+	Tested ok with kernel 2.6.12-rc2.
+
+2004-12-14 Karsten Wiese
+	Version 0.8.7.1:
+	snd_pcm_open for rawusb pcm-devices now returns -EBUSY if called without rawusb's hwdep device being open.
+
+2004-12-02 Karsten Wiese
+	Version 0.8.7:
+	Use macro usb_maxpacket() for portability.
+
+2004-10-26 Karsten Wiese
+	Version 0.8.6:
+	wake_up() process waiting in usx2y_urbs_start() on error.
+
+2004-10-21 Karsten Wiese
+	Version 0.8.5:
+	nrpacks is runtime or compiletime configurable now with tested values from 1 to 4.
+
+2004-10-03 Karsten Wiese
+	Version 0.8.2:
+	Avoid any possible racing while in prepare callback.
+
+2004-09-30 Karsten Wiese
+	Version 0.8.0:
+	Simplified things and made ohci work again.
+
+2004-09-20 Karsten Wiese
+	Version 0.7.3:
+	Use usb_kill_urb() instead of deprecated (kernel 2.6.9) usb_unlink_urb().
+
+2004-07-13 Karsten Wiese
+	Version 0.7.1:
+	Don't sleep in START/STOP callbacks anymore.
+	us428 channels C/D not handled just for this version, sorry.
+
+2004-06-21 Karsten Wiese
+	Version 0.6.4:
+	Temporarely suspend midi input
+	to sanely call usb_set_interface() when setting format.
+
+2004-06-12 Karsten Wiese
+	Version 0.6.3:
+	Made it thus the following rule is enforced:
+	"All pcm substreams of one usx2y have to operate at the same rate & format."
+
+2004-04-06 Karsten Wiese
+	Version 0.6.0:
+	Runs on 2.6.5 kernel without any "--with-debug=" things.
+	us224 reported running.
+
+2004-01-14 Karsten Wiese
+	Version 0.5.1:
+	Runs with 2.6.1 kernel.
+
+2003-12-30 Karsten Wiese
+	Version 0.4.1:
+	Fix 24Bit 4Channel capturing for the us428.
+
+2003-11-27 Karsten Wiese, Martin Langer
+	Version 0.4:
+	us122 support.
+	us224 could be tested by uncommenting the sections containing USB_ID_US224
+
+2003-11-03 Karsten Wiese
+	Version 0.3:
+	24Bit support.
+	"arecord -D hw:1 -c 2 -r 48000 -M -f S24_3LE|aplay -D hw:1 -c 2 -r 48000 -M -f S24_3LE" works.
+
+2003-08-22 Karsten Wiese
+	Version 0.0.8:
+	Removed EZUSB Firmware. First Stage Firmwaredownload is now done by tascam-firmware downloader.
+	See:
+	http://usb-midi-fw.sourceforge.net/tascam-firmware.tar.gz
+
+2003-06-18 Karsten Wiese
+	Version 0.0.5:
+	changed to compile with kernel 2.4.21 and alsa 0.9.4
+
+2002-10-16 Karsten Wiese
+	Version 0.0.4:
+	compiles again with alsa-current.
+	USB_ISO_ASAP not used anymore (most of the time), instead
+	urb->start_frame is calculated here now, some calls inside usb-driver don't need to happen anymore.
+
+	To get the best out of this:
+	Disable APM-support in the kernel as APM-BIOS calls (once each second) hard disable interrupt for many precious milliseconds.
+	This helped me much on my slowish PII 400 & PIII 500.
+	ACPI yet untested but might cause the same bad behaviour.
+	Use a kernel with lowlatency and preemptiv patches applied.
+	To autoload snd-usb-midi append a line
+		post-install snd-usb-us428 modprobe snd-usb-midi
+	to /etc/modules.conf.
+
+	known problems:
+	sliders, knobs, lights not yet handled except MASTER Volume slider.
+	"pcm -c 2" doesn't work. "pcm -c 2 -m direct_interleaved" does.
+	KDE3: "Enable full duplex operation" deadlocks.
+
+2002-08-31 Karsten Wiese
+	Version 0.0.3: audio also simplex;
+	simplifying: iso urbs only 1 packet, melted structs.
+	ASYNC_UNLINK not used anymore: no more crashes so far.....
+	for alsa 0.9 rc3.
+
+2002-08-09 Karsten Wiese
+	Version 0.0.2: midi works with snd-usb-midi, audio (only fullduplex now) with i.e. bristol.
+	The firmware has been sniffed from win2k us-428 driver 3.09.
+
+ *   Copyright (c) 2002 - 2004 Karsten Wiese
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/usb.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+
+#include <sound/rawmidi.h>
+#include "usx2y.h"
+#include "usbusx2y.h"
+#include "usX2Yhwdep.h"
+
+MODULE_AUTHOR("Karsten Wiese <annabellesgarden@yahoo.de>");
+MODULE_DESCRIPTION("TASCAM "NAME_ALLCAPS" Version 0.8.7.2");
+MODULE_LICENSE("GPL");
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-max */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* Id for this card */
+static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP; /* Enable this card */
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for "NAME_ALLCAPS".");
+module_param_array(id, charp, NULL, 0444);
+MODULE_PARM_DESC(id, "ID string for "NAME_ALLCAPS".");
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable "NAME_ALLCAPS".");
+
+static int snd_usx2y_card_used[SNDRV_CARDS];
+
+static void snd_usx2y_card_private_free(struct snd_card *card);
+static void usx2y_unlinkseq(struct snd_usx2y_async_seq *s);
+
+#ifdef USX2Y_NRPACKS_VARIABLE
+int nrpacks = USX2Y_NRPACKS; /* number of packets per urb */
+module_param(nrpacks, int, 0444);
+MODULE_PARM_DESC(nrpacks, "Number of packets per URB.");
+#endif
+
+/*
+ * pipe 4 is used for switching the lamps, setting samplerate, volumes ....
+ */
+static void i_usx2y_out04_int(struct urb *urb)
+{
+#ifdef CONFIG_SND_DEBUG
+	if (urb->status) {
+		int i;
+		struct usx2ydev *usx2y = urb->context;
+
+		for (i = 0; i < 10 && usx2y->as04.urb[i] != urb; i++)
+			;
+		dev_dbg(&urb->dev->dev, "%s urb %i status=%i\n", __func__, i, urb->status);
+	}
+#endif
+}
+
+static void i_usx2y_in04_int(struct urb *urb)
+{
+	int			err = 0;
+	struct usx2ydev		*usx2y = urb->context;
+	struct us428ctls_sharedmem	*us428ctls = usx2y->us428ctls_sharedmem;
+	struct us428_p4out *p4out;
+	int i, j, n, diff, send, len;
+
+	usx2y->in04_int_calls++;
+
+	if (urb->status) {
+		dev_dbg(&urb->dev->dev, "Interrupt Pipe 4 came back with status=%i\n", urb->status);
+		return;
+	}
+
+	if (us428ctls) {
+		diff = -1;
+		if (us428ctls->ctl_snapshot_last == -2) {
+			diff = 0;
+			memcpy(usx2y->in04_last, usx2y->in04_buf, sizeof(usx2y->in04_last));
+			us428ctls->ctl_snapshot_last = -1;
+		} else {
+			for (i = 0; i < 21; i++) {
+				if (usx2y->in04_last[i] != ((char *)usx2y->in04_buf)[i]) {
+					if (diff < 0)
+						diff = i;
+					usx2y->in04_last[i] = ((char *)usx2y->in04_buf)[i];
+				}
+			}
+		}
+		if (diff >= 0) {
+			n = us428ctls->ctl_snapshot_last + 1;
+			if (n >= N_US428_CTL_BUFS || n < 0)
+				n = 0;
+			memcpy(us428ctls->ctl_snapshot + n, usx2y->in04_buf, sizeof(us428ctls->ctl_snapshot[0]));
+			us428ctls->ctl_snapshot_differs_at[n] = diff;
+			us428ctls->ctl_snapshot_last = n;
+			wake_up(&usx2y->us428ctls_wait_queue_head);
+		}
+	}
+
+	if (usx2y->us04) {
+		if (!usx2y->us04->submitted) {
+			do {
+				err = usb_submit_urb(usx2y->us04->urb[usx2y->us04->submitted++], GFP_ATOMIC);
+			} while (!err && usx2y->us04->submitted < usx2y->us04->len);
+		}
+	} else {
+		while (us428ctls &&
+		       us428ctls->p4out_last >= 0 &&
+		       us428ctls->p4out_last < N_US428_P4OUT_BUFS &&
+		       us428ctls->p4out_last != us428ctls->p4out_sent) {
+			for (j = 0; j < URBS_ASYNC_SEQ && !err; ++j) {
+				if (!usx2y->as04.urb[j]->status) {
+					send = us428ctls->p4out_sent + 1;
+					if (send >= N_US428_P4OUT_BUFS)
+						send = 0;
+
+					p4out = us428ctls->p4out + send;
+					len = p4out->type == ELT_LIGHT ?
+						sizeof(struct us428_lights) : 5;
+					memcpy(usx2y->as04.urb[j]->transfer_buffer,
+					       &p4out->val.vol, len);
+					usx2y->as04.urb[j]->transfer_buffer_length = len;
+					err = usb_submit_urb(usx2y->as04.urb[j], GFP_ATOMIC);
+					if (!err)
+						us428ctls->p4out_sent = send;
+
+					break;
+				}
+			}
+			if (j >= URBS_ASYNC_SEQ || err)
+				break;
+		}
+	}
+
+	if (err)
+		dev_err(&urb->dev->dev, "in04_int() usb_submit_urb err=%i\n", err);
+
+	urb->dev = usx2y->dev;
+	usb_submit_urb(urb, GFP_ATOMIC);
+}
+
+/*
+ * Prepare some urbs
+ */
+int usx2y_async_seq04_init(struct usx2ydev *usx2y)
+{
+	int	err = 0, i;
+
+	if (WARN_ON(usx2y->as04.buffer))
+		return -EBUSY;
+
+	usx2y->as04.buffer = kmalloc_array(URBS_ASYNC_SEQ,
+					   URB_DATA_LEN_ASYNC_SEQ, GFP_KERNEL);
+	if (!usx2y->as04.buffer) {
+		err = -ENOMEM;
+	} else {
+		for (i = 0; i < URBS_ASYNC_SEQ; ++i) {
+			usx2y->as04.urb[i] = usb_alloc_urb(0, GFP_KERNEL);
+			if (!usx2y->as04.urb[i]) {
+				err = -ENOMEM;
+				break;
+			}
+			usb_fill_bulk_urb(usx2y->as04.urb[i], usx2y->dev,
+					  usb_sndbulkpipe(usx2y->dev, 0x04),
+					  usx2y->as04.buffer + URB_DATA_LEN_ASYNC_SEQ * i, 0,
+					  i_usx2y_out04_int, usx2y);
+			err = usb_urb_ep_type_check(usx2y->as04.urb[i]);
+			if (err < 0)
+				break;
+		}
+	}
+	if (err)
+		usx2y_unlinkseq(&usx2y->as04);
+	return err;
+}
+
+int usx2y_in04_init(struct usx2ydev *usx2y)
+{
+	int err;
+
+	if (WARN_ON(usx2y->in04_urb))
+		return -EBUSY;
+
+	usx2y->in04_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!usx2y->in04_urb) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	usx2y->in04_buf = kmalloc(21, GFP_KERNEL);
+	if (!usx2y->in04_buf) {
+		err = -ENOMEM;
+		goto error;
+	}
+
+	init_waitqueue_head(&usx2y->in04_wait_queue);
+	usb_fill_int_urb(usx2y->in04_urb, usx2y->dev, usb_rcvintpipe(usx2y->dev, 0x4),
+			 usx2y->in04_buf, 21,
+			 i_usx2y_in04_int, usx2y,
+			 10);
+	if (usb_urb_ep_type_check(usx2y->in04_urb)) {
+		err = -EINVAL;
+		goto error;
+	}
+	return usb_submit_urb(usx2y->in04_urb, GFP_KERNEL);
+
+ error:
+	kfree(usx2y->in04_buf);
+	usb_free_urb(usx2y->in04_urb);
+	usx2y->in04_buf = NULL;
+	usx2y->in04_urb = NULL;
+	return err;
+}
+
+static void usx2y_unlinkseq(struct snd_usx2y_async_seq *s)
+{
+	int	i;
+
+	for (i = 0; i < URBS_ASYNC_SEQ; ++i) {
+		if (!s->urb[i])
+			continue;
+		usb_kill_urb(s->urb[i]);
+		usb_free_urb(s->urb[i]);
+		s->urb[i] = NULL;
+	}
+	kfree(s->buffer);
+	s->buffer = NULL;
+}
+
+static const struct usb_device_id snd_usx2y_usb_id_table[] = {
+	{
+		.match_flags =	USB_DEVICE_ID_MATCH_DEVICE,
+		.idVendor =	0x1604,
+		.idProduct =	USB_ID_US428
+	},
+	{
+		.match_flags =	USB_DEVICE_ID_MATCH_DEVICE,
+		.idVendor =	0x1604,
+		.idProduct =	USB_ID_US122
+	},
+	{
+		.match_flags =	USB_DEVICE_ID_MATCH_DEVICE,
+		.idVendor =	0x1604,
+		.idProduct =	USB_ID_US224
+	},
+	{ /* terminator */ }
+};
+MODULE_DEVICE_TABLE(usb, snd_usx2y_usb_id_table);
+
+static int usx2y_create_card(struct usb_device *device,
+			     struct usb_interface *intf,
+			     struct snd_card **cardp)
+{
+	int		dev;
+	struct snd_card *card;
+	int err;
+
+	for (dev = 0; dev < SNDRV_CARDS; ++dev)
+		if (enable[dev] && !snd_usx2y_card_used[dev])
+			break;
+	if (dev >= SNDRV_CARDS)
+		return -ENODEV;
+	err = snd_card_new(&intf->dev, index[dev], id[dev], THIS_MODULE,
+			   sizeof(struct usx2ydev), &card);
+	if (err < 0)
+		return err;
+	snd_usx2y_card_used[usx2y(card)->card_index = dev] = 1;
+	card->private_free = snd_usx2y_card_private_free;
+	usx2y(card)->dev = device;
+	init_waitqueue_head(&usx2y(card)->prepare_wait_queue);
+	init_waitqueue_head(&usx2y(card)->us428ctls_wait_queue_head);
+	mutex_init(&usx2y(card)->pcm_mutex);
+	INIT_LIST_HEAD(&usx2y(card)->midi_list);
+	strscpy(card->driver, "USB "NAME_ALLCAPS"");
+	sprintf(card->shortname, "TASCAM "NAME_ALLCAPS"");
+	sprintf(card->longname, "%s (%x:%x if %d at %03d/%03d)",
+		card->shortname,
+		le16_to_cpu(device->descriptor.idVendor),
+		le16_to_cpu(device->descriptor.idProduct),
+		0,//us428(card)->usbmidi.ifnum,
+		usx2y(card)->dev->bus->busnum, usx2y(card)->dev->devnum);
+	*cardp = card;
+	return 0;
+}
+
+static void snd_usx2y_card_private_free(struct snd_card *card)
+{
+	struct usx2ydev *usx2y = usx2y(card);
+
+	kfree(usx2y->in04_buf);
+	usb_free_urb(usx2y->in04_urb);
+	if (usx2y->us428ctls_sharedmem)
+		free_pages_exact(usx2y->us428ctls_sharedmem,
+				 US428_SHAREDMEM_PAGES);
+	if (usx2y->card_index >= 0 && usx2y->card_index < SNDRV_CARDS)
+		snd_usx2y_card_used[usx2y->card_index] = 0;
+}
+
+static void snd_usx2y_disconnect(struct usb_interface *intf)
+{
+	struct snd_card *card;
+	struct usx2ydev *usx2y;
+	struct list_head *p;
+
+	card = usb_get_intfdata(intf);
+	if (!card)
+		return;
+	usx2y = usx2y(card);
+	usx2y->chip_status = USX2Y_STAT_CHIP_HUP;
+	usx2y_unlinkseq(&usx2y->as04);
+	usb_kill_urb(usx2y->in04_urb);
+	snd_card_disconnect(card);
+
+	/* release the midi resources */
+	list_for_each(p, &usx2y->midi_list) {
+		snd_usbmidi_disconnect(p);
+	}
+	if (usx2y->us428ctls_sharedmem)
+		wake_up(&usx2y->us428ctls_wait_queue_head);
+	snd_card_free_when_closed(card);
+}
+
+static int snd_usx2y_probe(struct usb_interface *intf,
+			   const struct usb_device_id *id)
+{
+	struct usb_device *device = interface_to_usbdev(intf);
+	struct snd_card *card;
+	int err;
+
+#ifdef USX2Y_NRPACKS_VARIABLE
+	if (nrpacks < 0 || nrpacks > USX2Y_NRPACKS_MAX)
+		return -EINVAL;
+#endif
+
+	if (le16_to_cpu(device->descriptor.idVendor) != 0x1604 ||
+	    (le16_to_cpu(device->descriptor.idProduct) != USB_ID_US122 &&
+	     le16_to_cpu(device->descriptor.idProduct) != USB_ID_US224 &&
+	     le16_to_cpu(device->descriptor.idProduct) != USB_ID_US428))
+		return -EINVAL;
+
+	err = usx2y_create_card(device, intf, &card);
+	if (err < 0)
+		return err;
+	err = usx2y_hwdep_new(card, device);
+	if (err < 0)
+		goto error;
+	err = snd_card_register(card);
+	if (err < 0)
+		goto error;
+
+	dev_set_drvdata(&intf->dev, card);
+	return 0;
+
+ error:
+	snd_card_free(card);
+	return err;
+}
+
+static struct usb_driver snd_usx2y_usb_driver = {
+	.name =		"snd-usb-usx2y",
+	.probe =	snd_usx2y_probe,
+	.disconnect =	snd_usx2y_disconnect,
+	.id_table =	snd_usx2y_usb_id_table,
+};
+module_usb_driver(snd_usx2y_usb_driver);
diff --git a/sound/usb/usx2y/usbusx2y.h b/sound/usb/usx2y/usbusx2y.h
new file mode 100644
index 000000000..6a76d04bf
--- /dev/null
+++ b/sound/usb/usx2y/usbusx2y.h
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef USBUSX2Y_H
+#define USBUSX2Y_H
+#include "../usbaudio.h"
+#include "../midi.h"
+#include "usbus428ctldefs.h"
+
+#define NRURBS	        2
+
+/* Default value used for nr of packs per urb.
+ * 1 to 4 have been tested ok on uhci.
+ * To use 3 on ohci, you'd need a patch:
+ * look for "0000425-linux-2.6.9-rc4-mm1_ohci-hcd.patch.gz" on
+ * "https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000425"
+ *
+ * 1, 2 and 4 work out of the box on ohci, if I recall correctly.
+ * Bigger is safer operation, smaller gives lower latencies.
+ */
+#define USX2Y_NRPACKS 4
+
+#define USX2Y_NRPACKS_MAX 1024
+
+/* If your system works ok with this module's parameter
+ * nrpacks set to 1, you might as well comment
+ * this define out, and thereby produce smaller, faster code.
+ * You'd also set USX2Y_NRPACKS to 1 then.
+ */
+#define USX2Y_NRPACKS_VARIABLE 1
+
+#ifdef USX2Y_NRPACKS_VARIABLE
+extern int nrpacks;
+#define nr_of_packs() nrpacks
+#else
+#define nr_of_packs() USX2Y_NRPACKS
+#endif
+
+#define URBS_ASYNC_SEQ 10
+#define URB_DATA_LEN_ASYNC_SEQ 32
+struct snd_usx2y_async_seq {
+	struct urb	*urb[URBS_ASYNC_SEQ];
+	char		*buffer;
+};
+
+struct snd_usx2y_urb_seq {
+	int	submitted;
+	int	len;
+	struct urb	*urb[] __counted_by(len);
+};
+
+#include "usx2yhwdeppcm.h"
+
+struct usx2ydev {
+	struct usb_device	*dev;
+	int			card_index;
+	int			stride;
+	struct urb		*in04_urb;
+	void			*in04_buf;
+	char			in04_last[24];
+	unsigned int		in04_int_calls;
+	struct snd_usx2y_urb_seq	*us04;
+	wait_queue_head_t	in04_wait_queue;
+	struct snd_usx2y_async_seq	as04;
+	unsigned int		rate,
+				format;
+	int			chip_status;
+	struct mutex		pcm_mutex;
+	struct us428ctls_sharedmem	*us428ctls_sharedmem;
+	int			wait_iso_frame;
+	wait_queue_head_t	us428ctls_wait_queue_head;
+	struct snd_usx2y_hwdep_pcm_shm	*hwdep_pcm_shm;
+	struct snd_usx2y_substream	*subs[4];
+	struct snd_usx2y_substream	* volatile  prepare_subs;
+	wait_queue_head_t	prepare_wait_queue;
+	struct list_head	midi_list;
+	int			pcm_devs;
+};
+
+
+struct snd_usx2y_substream {
+	struct usx2ydev	*usx2y;
+	struct snd_pcm_substream *pcm_substream;
+
+	int			endpoint;
+	unsigned int		maxpacksize;		/* max packet size in bytes */
+
+	atomic_t		state;
+#define STATE_STOPPED	0
+#define STATE_STARTING1 1
+#define STATE_STARTING2 2
+#define STATE_STARTING3 3
+#define STATE_PREPARED	4
+#define STATE_PRERUNNING  6
+#define STATE_RUNNING	8
+
+	int			hwptr;			/* free frame position in the buffer (only for playback) */
+	int			hwptr_done;		/* processed frame position in the buffer */
+	int			transfer_done;		/* processed frames since last period update */
+
+	struct urb		*urb[NRURBS];	/* data urb table */
+	struct urb		*completed_urb;
+	char			*tmpbuf;			/* temporary buffer for playback */
+};
+
+
+#define usx2y(c) ((struct usx2ydev *)(c)->private_data)
+
+int usx2y_audio_create(struct snd_card *card);
+
+int usx2y_async_seq04_init(struct usx2ydev *usx2y);
+int usx2y_in04_init(struct usx2ydev *usx2y);
+
+#define NAME_ALLCAPS "US-X2Y"
+
+#endif
diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c
new file mode 100644
index 000000000..a3a0bc136
--- /dev/null
+++ b/sound/usb/usx2y/usbusx2yaudio.c
@@ -0,0 +1,1007 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   US-X2Y AUDIO
+ *   Copyright (c) 2002-2004 by Karsten Wiese
+ *
+ *   based on
+ *
+ *   (Tentative) USB Audio Driver for ALSA
+ *
+ *   Main and PCM part
+ *
+ *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
+ *
+ *   Many codes borrowed from audio.c by
+ *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
+ *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
+ */
+
+
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/moduleparam.h>
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include "usx2y.h"
+#include "usbusx2y.h"
+
+static int usx2y_urb_capt_retire(struct snd_usx2y_substream *subs)
+{
+	struct urb	*urb = subs->completed_urb;
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+	unsigned char	*cp;
+	int		i, len, lens = 0, hwptr_done = subs->hwptr_done;
+	int		cnt, blen;
+	struct usx2ydev	*usx2y = subs->usx2y;
+
+	for (i = 0; i < nr_of_packs(); i++) {
+		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+		if (urb->iso_frame_desc[i].status) { /* active? hmm, skip this */
+			dev_err(&usx2y->dev->dev,
+				"%s: active frame status %i. Most probably some hardware problem.\n",
+				__func__,
+				urb->iso_frame_desc[i].status);
+			return urb->iso_frame_desc[i].status;
+		}
+		len = urb->iso_frame_desc[i].actual_length / usx2y->stride;
+		if (!len) {
+			dev_dbg(&usx2y->dev->dev, "%s: 0 == len ERROR!\n", __func__);
+			continue;
+		}
+
+		/* copy a data chunk */
+		if ((hwptr_done + len) > runtime->buffer_size) {
+			cnt = runtime->buffer_size - hwptr_done;
+			blen = cnt * usx2y->stride;
+			memcpy(runtime->dma_area + hwptr_done * usx2y->stride, cp, blen);
+			memcpy(runtime->dma_area, cp + blen, len * usx2y->stride - blen);
+		} else {
+			memcpy(runtime->dma_area + hwptr_done * usx2y->stride, cp,
+			       len * usx2y->stride);
+		}
+		lens += len;
+		hwptr_done += len;
+		if (hwptr_done >= runtime->buffer_size)
+			hwptr_done -= runtime->buffer_size;
+	}
+
+	subs->hwptr_done = hwptr_done;
+	subs->transfer_done += lens;
+	/* update the pointer, call callback if necessary */
+	if (subs->transfer_done >= runtime->period_size) {
+		subs->transfer_done -= runtime->period_size;
+		snd_pcm_period_elapsed(subs->pcm_substream);
+	}
+	return 0;
+}
+
+/*
+ * prepare urb for playback data pipe
+ *
+ * we copy the data directly from the pcm buffer.
+ * the current position to be copied is held in hwptr field.
+ * since a urb can handle only a single linear buffer, if the total
+ * transferred area overflows the buffer boundary, we cannot send
+ * it directly from the buffer.  thus the data is once copied to
+ * a temporary buffer and urb points to that.
+ */
+static int usx2y_urb_play_prepare(struct snd_usx2y_substream *subs,
+				  struct urb *cap_urb,
+				  struct urb *urb)
+{
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+	int count, counts, pack, len;
+
+	count = 0;
+	for (pack = 0; pack <  nr_of_packs(); pack++) {
+		/* calculate the size of a packet */
+		counts = cap_urb->iso_frame_desc[pack].actual_length / usx2y->stride;
+		count += counts;
+		if (counts < 43 || counts > 50) {
+			dev_err(&usx2y->dev->dev, "%s: should not be here with counts=%i\n",
+				__func__, counts);
+			return -EPIPE;
+		}
+		/* set up descriptor */
+		urb->iso_frame_desc[pack].offset = pack ?
+			urb->iso_frame_desc[pack - 1].offset +
+			urb->iso_frame_desc[pack - 1].length :
+			0;
+		urb->iso_frame_desc[pack].length = cap_urb->iso_frame_desc[pack].actual_length;
+	}
+	if (atomic_read(&subs->state) >= STATE_PRERUNNING) {
+		if (subs->hwptr + count > runtime->buffer_size) {
+			/* err, the transferred area goes over buffer boundary.
+			 * copy the data to the temp buffer.
+			 */
+			len = runtime->buffer_size - subs->hwptr;
+			urb->transfer_buffer = subs->tmpbuf;
+			memcpy(subs->tmpbuf, runtime->dma_area +
+			       subs->hwptr * usx2y->stride, len * usx2y->stride);
+			memcpy(subs->tmpbuf + len * usx2y->stride,
+			       runtime->dma_area, (count - len) * usx2y->stride);
+			subs->hwptr += count;
+			subs->hwptr -= runtime->buffer_size;
+		} else {
+			/* set the buffer pointer */
+			urb->transfer_buffer = runtime->dma_area + subs->hwptr * usx2y->stride;
+			subs->hwptr += count;
+			if (subs->hwptr >= runtime->buffer_size)
+				subs->hwptr -= runtime->buffer_size;
+		}
+	} else {
+		urb->transfer_buffer = subs->tmpbuf;
+	}
+	urb->transfer_buffer_length = count * usx2y->stride;
+	return 0;
+}
+
+/*
+ * process after playback data complete
+ *
+ * update the current position and call callback if a period is processed.
+ */
+static void usx2y_urb_play_retire(struct snd_usx2y_substream *subs, struct urb *urb)
+{
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+	int		len = urb->actual_length / subs->usx2y->stride;
+
+	subs->transfer_done += len;
+	subs->hwptr_done +=  len;
+	if (subs->hwptr_done >= runtime->buffer_size)
+		subs->hwptr_done -= runtime->buffer_size;
+	if (subs->transfer_done >= runtime->period_size) {
+		subs->transfer_done -= runtime->period_size;
+		snd_pcm_period_elapsed(subs->pcm_substream);
+	}
+}
+
+static int usx2y_urb_submit(struct snd_usx2y_substream *subs, struct urb *urb, int frame)
+{
+	int err;
+
+	if (!urb)
+		return -ENODEV;
+	urb->start_frame = frame + NRURBS * nr_of_packs();  // let hcd do rollover sanity checks
+	urb->dev = subs->usx2y->dev; /* we need to set this at each time */
+	err = usb_submit_urb(urb, GFP_ATOMIC);
+	if (err < 0) {
+		dev_err(&urb->dev->dev, "%s: usb_submit_urb() returned %i\n",
+			__func__, err);
+		return err;
+	}
+	return 0;
+}
+
+static int usx2y_usbframe_complete(struct snd_usx2y_substream *capsubs,
+				   struct snd_usx2y_substream *playbacksubs,
+				   int frame)
+{
+	int err, state;
+	struct urb *urb = playbacksubs->completed_urb;
+
+	state = atomic_read(&playbacksubs->state);
+	if (urb) {
+		if (state == STATE_RUNNING)
+			usx2y_urb_play_retire(playbacksubs, urb);
+		else if (state >= STATE_PRERUNNING)
+			atomic_inc(&playbacksubs->state);
+	} else {
+		switch (state) {
+		case STATE_STARTING1:
+			urb = playbacksubs->urb[0];
+			atomic_inc(&playbacksubs->state);
+			break;
+		case STATE_STARTING2:
+			urb = playbacksubs->urb[1];
+			atomic_inc(&playbacksubs->state);
+			break;
+		}
+	}
+	if (urb) {
+		err = usx2y_urb_play_prepare(playbacksubs, capsubs->completed_urb, urb);
+		if (err)
+			return err;
+		err = usx2y_urb_submit(playbacksubs, urb, frame);
+		if (err)
+			return err;
+	}
+
+	playbacksubs->completed_urb = NULL;
+
+	state = atomic_read(&capsubs->state);
+	if (state >= STATE_PREPARED) {
+		if (state == STATE_RUNNING) {
+			err = usx2y_urb_capt_retire(capsubs);
+			if (err)
+				return err;
+		} else if (state >= STATE_PRERUNNING) {
+			atomic_inc(&capsubs->state);
+		}
+		err = usx2y_urb_submit(capsubs, capsubs->completed_urb, frame);
+		if (err)
+			return err;
+	}
+	capsubs->completed_urb = NULL;
+	return 0;
+}
+
+static void usx2y_clients_stop(struct usx2ydev *usx2y)
+{
+	struct snd_usx2y_substream *subs;
+	struct urb *urb;
+	int s, u;
+
+	for (s = 0; s < 4; s++) {
+		subs = usx2y->subs[s];
+		if (subs) {
+			dev_dbg(&usx2y->dev->dev, "%s: %i %p state=%i\n",
+				__func__, s, subs, atomic_read(&subs->state));
+			atomic_set(&subs->state, STATE_STOPPED);
+		}
+	}
+	for (s = 0; s < 4; s++) {
+		subs = usx2y->subs[s];
+		if (subs) {
+			if (atomic_read(&subs->state) >= STATE_PRERUNNING)
+				snd_pcm_stop_xrun(subs->pcm_substream);
+			for (u = 0; u < NRURBS; u++) {
+				urb = subs->urb[u];
+				if (urb)
+					dev_dbg(&usx2y->dev->dev,
+						"%s: %i status=%i start_frame=%i\n",
+						__func__, u, urb->status, urb->start_frame);
+			}
+		}
+	}
+	usx2y->prepare_subs = NULL;
+	wake_up(&usx2y->prepare_wait_queue);
+}
+
+static void usx2y_error_urb_status(struct usx2ydev *usx2y,
+				   struct snd_usx2y_substream *subs, struct urb *urb)
+{
+	dev_err(&usx2y->dev->dev, "%s: ep=%i stalled with status=%i\n",
+		__func__, subs->endpoint, urb->status);
+	urb->status = 0;
+	usx2y_clients_stop(usx2y);
+}
+
+static void i_usx2y_urb_complete(struct urb *urb)
+{
+	struct snd_usx2y_substream *subs = urb->context;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *capsubs, *playbacksubs;
+
+	if (unlikely(atomic_read(&subs->state) < STATE_PREPARED)) {
+		dev_dbg(&usx2y->dev->dev,
+			"%s: hcd_frame=%i ep=%i%s status=%i start_frame=%i\n",
+			__func__,
+			usb_get_current_frame_number(usx2y->dev),
+			subs->endpoint, usb_pipein(urb->pipe) ? "in" : "out",
+			urb->status, urb->start_frame);
+		return;
+	}
+	if (unlikely(urb->status)) {
+		usx2y_error_urb_status(usx2y, subs, urb);
+		return;
+	}
+
+	subs->completed_urb = urb;
+
+	capsubs = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+	playbacksubs = usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+
+	if (capsubs->completed_urb &&
+	    atomic_read(&capsubs->state) >= STATE_PREPARED &&
+	    (playbacksubs->completed_urb ||
+	     atomic_read(&playbacksubs->state) < STATE_PREPARED)) {
+		if (!usx2y_usbframe_complete(capsubs, playbacksubs, urb->start_frame)) {
+			usx2y->wait_iso_frame += nr_of_packs();
+		} else {
+			usx2y_clients_stop(usx2y);
+		}
+	}
+}
+
+static void usx2y_urbs_set_complete(struct usx2ydev *usx2y,
+				    void (*complete)(struct urb *))
+{
+	struct snd_usx2y_substream *subs;
+	struct urb *urb;
+	int s, u;
+
+	for (s = 0; s < 4; s++) {
+		subs = usx2y->subs[s];
+		if (subs) {
+			for (u = 0; u < NRURBS; u++) {
+				urb = subs->urb[u];
+				if (urb)
+					urb->complete = complete;
+			}
+		}
+	}
+}
+
+static void usx2y_subs_startup_finish(struct usx2ydev *usx2y)
+{
+	usx2y_urbs_set_complete(usx2y, i_usx2y_urb_complete);
+	usx2y->prepare_subs = NULL;
+}
+
+static void i_usx2y_subs_startup(struct urb *urb)
+{
+	struct snd_usx2y_substream *subs = urb->context;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *prepare_subs = usx2y->prepare_subs;
+
+	if (prepare_subs) {
+		if (urb->start_frame == prepare_subs->urb[0]->start_frame) {
+			usx2y_subs_startup_finish(usx2y);
+			atomic_inc(&prepare_subs->state);
+			wake_up(&usx2y->prepare_wait_queue);
+		}
+	}
+
+	i_usx2y_urb_complete(urb);
+}
+
+static void usx2y_subs_prepare(struct snd_usx2y_substream *subs)
+{
+	dev_dbg(&subs->usx2y->dev->dev,
+		"%s(%p) ep=%i urb0=%p urb1=%p\n",
+		__func__, subs, subs->endpoint, subs->urb[0], subs->urb[1]);
+	/* reset the pointer */
+	subs->hwptr = 0;
+	subs->hwptr_done = 0;
+	subs->transfer_done = 0;
+}
+
+static void usx2y_urb_release(struct urb **urb, int free_tb)
+{
+	if (*urb) {
+		usb_kill_urb(*urb);
+		if (free_tb)
+			kfree((*urb)->transfer_buffer);
+		usb_free_urb(*urb);
+		*urb = NULL;
+	}
+}
+
+/*
+ * release a substreams urbs
+ */
+static void usx2y_urbs_release(struct snd_usx2y_substream *subs)
+{
+	int i;
+
+	dev_dbg(&subs->usx2y->dev->dev, "%s %i\n", __func__, subs->endpoint);
+	for (i = 0; i < NRURBS; i++)
+		usx2y_urb_release(subs->urb + i,
+				  subs != subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK]);
+
+	kfree(subs->tmpbuf);
+	subs->tmpbuf = NULL;
+}
+
+/*
+ * initialize a substream's urbs
+ */
+static int usx2y_urbs_allocate(struct snd_usx2y_substream *subs)
+{
+	int i;
+	unsigned int pipe;
+	int is_playback = subs == subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+	struct usb_device *dev = subs->usx2y->dev;
+	struct urb **purb;
+
+	pipe = is_playback ? usb_sndisocpipe(dev, subs->endpoint) :
+			usb_rcvisocpipe(dev, subs->endpoint);
+	subs->maxpacksize = usb_maxpacket(dev, pipe);
+	if (!subs->maxpacksize)
+		return -EINVAL;
+
+	if (is_playback && !subs->tmpbuf) {	/* allocate a temporary buffer for playback */
+		subs->tmpbuf = kcalloc(nr_of_packs(), subs->maxpacksize, GFP_KERNEL);
+		if (!subs->tmpbuf)
+			return -ENOMEM;
+	}
+	/* allocate and initialize data urbs */
+	for (i = 0; i < NRURBS; i++) {
+		purb = subs->urb + i;
+		if (*purb) {
+			usb_kill_urb(*purb);
+			continue;
+		}
+		*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
+		if (!*purb) {
+			usx2y_urbs_release(subs);
+			return -ENOMEM;
+		}
+		if (!is_playback && !(*purb)->transfer_buffer) {
+			/* allocate a capture buffer per urb */
+			(*purb)->transfer_buffer =
+				kmalloc_array(subs->maxpacksize,
+					      nr_of_packs(), GFP_KERNEL);
+			if (!(*purb)->transfer_buffer) {
+				usx2y_urbs_release(subs);
+				return -ENOMEM;
+			}
+		}
+		(*purb)->dev = dev;
+		(*purb)->pipe = pipe;
+		(*purb)->number_of_packets = nr_of_packs();
+		(*purb)->context = subs;
+		(*purb)->interval = 1;
+		(*purb)->complete = i_usx2y_subs_startup;
+	}
+	return 0;
+}
+
+static void usx2y_subs_startup(struct snd_usx2y_substream *subs)
+{
+	struct usx2ydev *usx2y = subs->usx2y;
+
+	usx2y->prepare_subs = subs;
+	subs->urb[0]->start_frame = -1;
+	wmb();
+	usx2y_urbs_set_complete(usx2y, i_usx2y_subs_startup);
+}
+
+static int usx2y_urbs_start(struct snd_usx2y_substream *subs)
+{
+	int i, err;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct urb *urb;
+	unsigned long pack;
+
+	err = usx2y_urbs_allocate(subs);
+	if (err < 0)
+		return err;
+	subs->completed_urb = NULL;
+	for (i = 0; i < 4; i++) {
+		struct snd_usx2y_substream *subs = usx2y->subs[i];
+
+		if (subs && atomic_read(&subs->state) >= STATE_PREPARED)
+			goto start;
+	}
+
+ start:
+	usx2y_subs_startup(subs);
+	for (i = 0; i < NRURBS; i++) {
+		urb = subs->urb[i];
+		if (usb_pipein(urb->pipe)) {
+			if (!i)
+				atomic_set(&subs->state, STATE_STARTING3);
+			urb->dev = usx2y->dev;
+			for (pack = 0; pack < nr_of_packs(); pack++) {
+				urb->iso_frame_desc[pack].offset = subs->maxpacksize * pack;
+				urb->iso_frame_desc[pack].length = subs->maxpacksize;
+			}
+			urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs();
+			err = usb_submit_urb(urb, GFP_ATOMIC);
+			if (err < 0) {
+				dev_err(&urb->dev->dev, "%s: cannot submit datapipe for urb %d, err = %d\n",
+					__func__, i, err);
+				err = -EPIPE;
+				goto cleanup;
+			} else {
+				if (!i)
+					usx2y->wait_iso_frame = urb->start_frame;
+			}
+			urb->transfer_flags = 0;
+		} else {
+			atomic_set(&subs->state, STATE_STARTING1);
+			break;
+		}
+	}
+	err = 0;
+	wait_event(usx2y->prepare_wait_queue, !usx2y->prepare_subs);
+	if (atomic_read(&subs->state) != STATE_PREPARED)
+		err = -EPIPE;
+
+ cleanup:
+	if (err) {
+		usx2y_subs_startup_finish(usx2y);
+		usx2y_clients_stop(usx2y);	// something is completely wrong > stop everything
+	}
+	return err;
+}
+
+/*
+ * return the current pcm pointer.  just return the hwptr_done value.
+ */
+static snd_pcm_uframes_t snd_usx2y_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_usx2y_substream *subs = substream->runtime->private_data;
+
+	return subs->hwptr_done;
+}
+
+/*
+ * start/stop substream
+ */
+static int snd_usx2y_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_usx2y_substream *subs = substream->runtime->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		dev_dbg(&subs->usx2y->dev->dev, "%s(START)\n", __func__);
+		if (atomic_read(&subs->state) == STATE_PREPARED &&
+		    atomic_read(&subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE]->state) >= STATE_PREPARED) {
+			atomic_set(&subs->state, STATE_PRERUNNING);
+		} else {
+			return -EPIPE;
+		}
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		dev_dbg(&subs->usx2y->dev->dev, "%s(STOP)\n", __func__);
+		if (atomic_read(&subs->state) >= STATE_PRERUNNING)
+			atomic_set(&subs->state, STATE_PREPARED);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * allocate a buffer, setup samplerate
+ *
+ * so far we use a physically linear buffer although packetize transfer
+ * doesn't need a continuous area.
+ * if sg buffer is supported on the later version of alsa, we'll follow
+ * that.
+ */
+struct s_c2 {
+	char c1, c2;
+};
+
+static const struct s_c2 setrate_44100[] = {
+	{ 0x14, 0x08},	// this line sets 44100, well actually a little less
+	{ 0x18, 0x40},	// only tascam / frontier design knows the further lines .......
+	{ 0x18, 0x42},
+	{ 0x18, 0x45},
+	{ 0x18, 0x46},
+	{ 0x18, 0x48},
+	{ 0x18, 0x4A},
+	{ 0x18, 0x4C},
+	{ 0x18, 0x4E},
+	{ 0x18, 0x50},
+	{ 0x18, 0x52},
+	{ 0x18, 0x54},
+	{ 0x18, 0x56},
+	{ 0x18, 0x58},
+	{ 0x18, 0x5A},
+	{ 0x18, 0x5C},
+	{ 0x18, 0x5E},
+	{ 0x18, 0x60},
+	{ 0x18, 0x62},
+	{ 0x18, 0x64},
+	{ 0x18, 0x66},
+	{ 0x18, 0x68},
+	{ 0x18, 0x6A},
+	{ 0x18, 0x6C},
+	{ 0x18, 0x6E},
+	{ 0x18, 0x70},
+	{ 0x18, 0x72},
+	{ 0x18, 0x74},
+	{ 0x18, 0x76},
+	{ 0x18, 0x78},
+	{ 0x18, 0x7A},
+	{ 0x18, 0x7C},
+	{ 0x18, 0x7E}
+};
+
+static const struct s_c2 setrate_48000[] = {
+	{ 0x14, 0x09},	// this line sets 48000, well actually a little less
+	{ 0x18, 0x40},	// only tascam / frontier design knows the further lines .......
+	{ 0x18, 0x42},
+	{ 0x18, 0x45},
+	{ 0x18, 0x46},
+	{ 0x18, 0x48},
+	{ 0x18, 0x4A},
+	{ 0x18, 0x4C},
+	{ 0x18, 0x4E},
+	{ 0x18, 0x50},
+	{ 0x18, 0x52},
+	{ 0x18, 0x54},
+	{ 0x18, 0x56},
+	{ 0x18, 0x58},
+	{ 0x18, 0x5A},
+	{ 0x18, 0x5C},
+	{ 0x18, 0x5E},
+	{ 0x18, 0x60},
+	{ 0x18, 0x62},
+	{ 0x18, 0x64},
+	{ 0x18, 0x66},
+	{ 0x18, 0x68},
+	{ 0x18, 0x6A},
+	{ 0x18, 0x6C},
+	{ 0x18, 0x6E},
+	{ 0x18, 0x70},
+	{ 0x18, 0x73},
+	{ 0x18, 0x74},
+	{ 0x18, 0x76},
+	{ 0x18, 0x78},
+	{ 0x18, 0x7A},
+	{ 0x18, 0x7C},
+	{ 0x18, 0x7E}
+};
+
+#define NOOF_SETRATE_URBS ARRAY_SIZE(setrate_48000)
+
+static void i_usx2y_04int(struct urb *urb)
+{
+	struct usx2ydev *usx2y = urb->context;
+
+	if (urb->status)
+		dev_err(&urb->dev->dev, "%s() urb->status=%i\n",
+			__func__, urb->status);
+	if (!--usx2y->us04->len)
+		wake_up(&usx2y->in04_wait_queue);
+}
+
+static int usx2y_rate_set(struct usx2ydev *usx2y, int rate)
+{
+	int err = 0, i;
+	struct snd_usx2y_urb_seq *us = NULL;
+	int *usbdata = NULL;
+	const struct s_c2 *ra = rate == 48000 ? setrate_48000 : setrate_44100;
+	struct urb *urb;
+
+	if (usx2y->rate != rate) {
+		us = kzalloc_flex(*us, urb, NOOF_SETRATE_URBS);
+		if (!us) {
+			err = -ENOMEM;
+			goto cleanup;
+		}
+		us->len = NOOF_SETRATE_URBS;
+		usbdata = kmalloc_objs(int, NOOF_SETRATE_URBS);
+		if (!usbdata) {
+			err = -ENOMEM;
+			goto cleanup;
+		}
+		for (i = 0; i < NOOF_SETRATE_URBS; ++i) {
+			us->urb[i] = usb_alloc_urb(0, GFP_KERNEL);
+			if (!us->urb[i]) {
+				err = -ENOMEM;
+				goto cleanup;
+			}
+			((char *)(usbdata + i))[0] = ra[i].c1;
+			((char *)(usbdata + i))[1] = ra[i].c2;
+			usb_fill_bulk_urb(us->urb[i], usx2y->dev, usb_sndbulkpipe(usx2y->dev, 4),
+					  usbdata + i, 2, i_usx2y_04int, usx2y);
+		}
+		err = usb_urb_ep_type_check(us->urb[0]);
+		if (err < 0)
+			goto cleanup;
+		us->submitted =	0;
+		usx2y->us04 =	us;
+		wait_event_timeout(usx2y->in04_wait_queue, !us->len, HZ);
+		usx2y->us04 =	NULL;
+		if (us->len)
+			err = -ENODEV;
+	cleanup:
+		if (us) {
+			us->submitted =	2*NOOF_SETRATE_URBS;
+			for (i = 0; i < NOOF_SETRATE_URBS; ++i) {
+				urb = us->urb[i];
+				if (!urb)
+					continue;
+				if (urb->status) {
+					if (!err)
+						err = -ENODEV;
+					usb_kill_urb(urb);
+				}
+				usb_free_urb(urb);
+			}
+			usx2y->us04 = NULL;
+			kfree(usbdata);
+			kfree(us);
+			if (!err)
+				usx2y->rate = rate;
+		}
+	}
+
+	return err;
+}
+
+static int usx2y_format_set(struct usx2ydev *usx2y, snd_pcm_format_t format)
+{
+	int alternate, err;
+	struct list_head *p;
+
+	if (format == SNDRV_PCM_FORMAT_S24_3LE) {
+		alternate = 2;
+		usx2y->stride = 6;
+	} else {
+		alternate = 1;
+		usx2y->stride = 4;
+	}
+	list_for_each(p, &usx2y->midi_list) {
+		snd_usbmidi_input_stop(p);
+	}
+	usb_kill_urb(usx2y->in04_urb);
+	err = usb_set_interface(usx2y->dev, 0, alternate);
+	if (err) {
+		dev_err(&usx2y->dev->dev, "%s: usb_set_interface error\n",
+			__func__);
+		return err;
+	}
+	usx2y->in04_urb->dev = usx2y->dev;
+	err = usb_submit_urb(usx2y->in04_urb, GFP_KERNEL);
+	list_for_each(p, &usx2y->midi_list) {
+		snd_usbmidi_input_start(p);
+	}
+	usx2y->format = format;
+	usx2y->rate = 0;
+	return err;
+}
+
+
+static int snd_usx2y_pcm_hw_params(struct snd_pcm_substream *substream,
+				   struct snd_pcm_hw_params *hw_params)
+{
+	unsigned int		rate = params_rate(hw_params);
+	snd_pcm_format_t	format = params_format(hw_params);
+	struct snd_card *card = substream->pstr->pcm->card;
+	struct usx2ydev	*dev = usx2y(card);
+	struct snd_usx2y_substream *subs;
+	struct snd_pcm_substream *test_substream;
+	int i;
+
+	guard(mutex)(&usx2y(card)->pcm_mutex);
+	dev_dbg(&dev->dev->dev, "%s(%p, %p)\n", __func__, substream, hw_params);
+	/* all pcm substreams off one usx2y have to operate at the same
+	 * rate & format
+	 */
+	for (i = 0; i < dev->pcm_devs * 2; i++) {
+		subs = dev->subs[i];
+		if (!subs)
+			continue;
+		test_substream = subs->pcm_substream;
+		if (!test_substream || test_substream == substream ||
+		    !test_substream->runtime)
+			continue;
+		if ((test_substream->runtime->format &&
+		     test_substream->runtime->format != format) ||
+		    (test_substream->runtime->rate &&
+		     test_substream->runtime->rate != rate)) {
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * free the buffer
+ */
+static int snd_usx2y_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+	struct snd_usx2y_substream *cap_subs, *playback_subs;
+
+	guard(mutex)(&subs->usx2y->pcm_mutex);
+	dev_dbg(&subs->usx2y->dev->dev, "%s(%p)\n", __func__, substream);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		cap_subs = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+		atomic_set(&subs->state, STATE_STOPPED);
+		usx2y_urbs_release(subs);
+		if (!cap_subs->pcm_substream ||
+		    !cap_subs->pcm_substream->runtime ||
+		    cap_subs->pcm_substream->runtime->state < SNDRV_PCM_STATE_PREPARED) {
+			atomic_set(&cap_subs->state, STATE_STOPPED);
+			usx2y_urbs_release(cap_subs);
+		}
+	} else {
+		playback_subs = subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+		if (atomic_read(&playback_subs->state) < STATE_PREPARED) {
+			atomic_set(&subs->state, STATE_STOPPED);
+			usx2y_urbs_release(subs);
+		}
+	}
+	return 0;
+}
+
+/*
+ * prepare callback
+ *
+ * set format and initialize urbs
+ */
+static int snd_usx2y_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *capsubs = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+	int err = 0;
+
+	dev_dbg(&usx2y->dev->dev, "%s(%p)\n", __func__, substream);
+
+	guard(mutex)(&usx2y->pcm_mutex);
+	usx2y_subs_prepare(subs);
+	// Start hardware streams
+	// SyncStream first....
+	if (atomic_read(&capsubs->state) < STATE_PREPARED) {
+		if (usx2y->format != runtime->format) {
+			err = usx2y_format_set(usx2y, runtime->format);
+			if (err < 0)
+				return err;
+		}
+		if (usx2y->rate != runtime->rate) {
+			err = usx2y_rate_set(usx2y, runtime->rate);
+			if (err < 0)
+				return err;
+		}
+		dev_dbg(&usx2y->dev->dev, "%s: starting capture pipe for %s\n",
+			__func__, subs == capsubs ? "self" : "playpipe");
+		err = usx2y_urbs_start(capsubs);
+		if (err < 0)
+			return err;
+	}
+
+	if (subs != capsubs && atomic_read(&subs->state) < STATE_PREPARED)
+		err = usx2y_urbs_start(subs);
+
+	return err;
+}
+
+static const struct snd_pcm_hardware snd_usx2y_2c = {
+	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
+				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				 SNDRV_PCM_INFO_MMAP_VALID |
+				 SNDRV_PCM_INFO_BATCH),
+	.formats =                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
+	.rates =                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
+	.rate_min =                44100,
+	.rate_max =                48000,
+	.channels_min =            2,
+	.channels_max =            2,
+	.buffer_bytes_max =	(2*128*1024),
+	.period_bytes_min =	64,
+	.period_bytes_max =	(128*1024),
+	.periods_min =		2,
+	.periods_max =		1024,
+	.fifo_size =              0
+};
+
+static int snd_usx2y_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_usx2y_substream	*subs =
+		((struct snd_usx2y_substream **)
+		 snd_pcm_substream_chip(substream))[substream->stream];
+	struct snd_pcm_runtime	*runtime = substream->runtime;
+
+	if (subs->usx2y->chip_status & USX2Y_STAT_CHIP_MMAP_PCM_URBS)
+		return -EBUSY;
+
+	runtime->hw = snd_usx2y_2c;
+	runtime->private_data = subs;
+	subs->pcm_substream = substream;
+	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 1000, 200000);
+	return 0;
+}
+
+static int snd_usx2y_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+
+	subs->pcm_substream = NULL;
+
+	return 0;
+}
+
+static const struct snd_pcm_ops snd_usx2y_pcm_ops = {
+	.open =		snd_usx2y_pcm_open,
+	.close =	snd_usx2y_pcm_close,
+	.hw_params =	snd_usx2y_pcm_hw_params,
+	.hw_free =	snd_usx2y_pcm_hw_free,
+	.prepare =	snd_usx2y_pcm_prepare,
+	.trigger =	snd_usx2y_pcm_trigger,
+	.pointer =	snd_usx2y_pcm_pointer,
+};
+
+/*
+ * free a usb stream instance
+ */
+static void usx2y_audio_stream_free(struct snd_usx2y_substream **usx2y_substream)
+{
+	int stream;
+
+	for_each_pcm_streams(stream) {
+		kfree(usx2y_substream[stream]);
+		usx2y_substream[stream] = NULL;
+	}
+}
+
+static void snd_usx2y_pcm_private_free(struct snd_pcm *pcm)
+{
+	struct snd_usx2y_substream **usx2y_stream = pcm->private_data;
+
+	if (usx2y_stream)
+		usx2y_audio_stream_free(usx2y_stream);
+}
+
+static int usx2y_audio_stream_new(struct snd_card *card, int playback_endpoint, int capture_endpoint)
+{
+	struct snd_pcm *pcm;
+	int err, i;
+	struct snd_usx2y_substream **usx2y_substream =
+		usx2y(card)->subs + 2 * usx2y(card)->pcm_devs;
+
+	for (i = playback_endpoint ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
+	     i <= SNDRV_PCM_STREAM_CAPTURE; ++i) {
+		usx2y_substream[i] = kzalloc_obj(struct snd_usx2y_substream);
+		if (!usx2y_substream[i])
+			return -ENOMEM;
+
+		usx2y_substream[i]->usx2y = usx2y(card);
+	}
+
+	if (playback_endpoint)
+		usx2y_substream[SNDRV_PCM_STREAM_PLAYBACK]->endpoint = playback_endpoint;
+	usx2y_substream[SNDRV_PCM_STREAM_CAPTURE]->endpoint = capture_endpoint;
+
+	err = snd_pcm_new(card, NAME_ALLCAPS" Audio", usx2y(card)->pcm_devs,
+			  playback_endpoint ? 1 : 0, 1,
+			  &pcm);
+	if (err < 0) {
+		usx2y_audio_stream_free(usx2y_substream);
+		return err;
+	}
+
+	if (playback_endpoint)
+		snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_usx2y_pcm_ops);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_usx2y_pcm_ops);
+
+	pcm->private_data = usx2y_substream;
+	pcm->private_free = snd_usx2y_pcm_private_free;
+	pcm->info_flags = 0;
+
+	sprintf(pcm->name, NAME_ALLCAPS" Audio #%d", usx2y(card)->pcm_devs);
+
+	if (playback_endpoint) {
+		snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream,
+					   SNDRV_DMA_TYPE_CONTINUOUS,
+					   NULL,
+					   64*1024, 128*1024);
+	}
+
+	snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
+				   SNDRV_DMA_TYPE_CONTINUOUS,
+				   NULL,
+				   64*1024, 128*1024);
+	usx2y(card)->pcm_devs++;
+
+	return 0;
+}
+
+/*
+ * create a chip instance and set its names.
+ */
+int usx2y_audio_create(struct snd_card *card)
+{
+	int err;
+
+	err = usx2y_audio_stream_new(card, 0xA, 0x8);
+	if (err < 0)
+		return err;
+	if (le16_to_cpu(usx2y(card)->dev->descriptor.idProduct) == USB_ID_US428) {
+		err = usx2y_audio_stream_new(card, 0, 0xA);
+		if (err < 0)
+			return err;
+	}
+	if (le16_to_cpu(usx2y(card)->dev->descriptor.idProduct) != USB_ID_US122)
+		err = usx2y_rate_set(usx2y(card), 44100);	// Lets us428 recognize output-volume settings, disturbs us122.
+	return err;
+}
diff --git a/sound/usb/usx2y/usx2y.h b/sound/usb/usx2y/usx2y.h
new file mode 100644
index 000000000..780071ddd
--- /dev/null
+++ b/sound/usb/usx2y/usx2y.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Driver for Tascam US-X2Y USB soundcards
+ *
+ * Copyright (c) 2003 by Karsten Wiese <annabellesgarden@yahoo.de>
+ */
+
+#ifndef __SOUND_USX2Y_COMMON_H
+#define __SOUND_USX2Y_COMMON_H
+
+
+#define USX2Y_DRIVER_VERSION	0x0100	/* 0.1.0 */
+
+
+/* hwdep id string */
+#define SND_USX2Y_LOADER_ID		"USX2Y Loader"
+#define SND_USX2Y_USBPCM_ID		"USX2Y USBPCM"
+
+/* hardware type */
+enum {
+	USX2Y_TYPE_122,
+	USX2Y_TYPE_224,
+	USX2Y_TYPE_428,
+	USX2Y_TYPE_NUMS
+};
+
+#define USB_ID_US122 0x8007
+#define USB_ID_US224 0x8005
+#define USB_ID_US428 0x8001
+
+/* chip status */
+enum {
+	USX2Y_STAT_CHIP_INIT	=	(1 << 0),	/* all operational */
+	USX2Y_STAT_CHIP_MMAP_PCM_URBS = (1 << 1),	/* pcm transport over mmaped urbs */
+	USX2Y_STAT_CHIP_HUP	=	(1 << 31),	/* all operational */
+};
+
+#endif /* __SOUND_USX2Y_COMMON_H */
diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
new file mode 100644
index 000000000..f1d5b4b79
--- /dev/null
+++ b/sound/usb/usx2y/usx2yhwdeppcm.c
@@ -0,0 +1,774 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ */
+
+/* USX2Y "rawusb" aka hwdep_pcm implementation
+
+ Its usb's unableness to atomically handle power of 2 period sized data chuncs
+ at standard samplerates,
+ what led to this part of the usx2y module:
+ It provides the alsa kernel half of the usx2y-alsa-jack driver pair.
+ The pair uses a hardware dependent alsa-device for mmaped pcm transport.
+ Advantage achieved:
+         The usb_hc moves pcm data from/into memory via DMA.
+         That memory is mmaped by jack's usx2y driver.
+         Jack's usx2y driver is the first/last to read/write pcm data.
+         Read/write is a combination of power of 2 period shaping and
+         float/int conversation.
+         Compared to mainline alsa/jack we leave out power of 2 period shaping inside
+         snd-usb-usx2y which needs memcpy() and additional buffers.
+         As a side effect possible unwanted pcm-data coruption resulting of
+         standard alsa's snd-usb-usx2y period shaping scheme falls away.
+         Result is sane jack operation at buffering schemes down to 128frames,
+         2 periods.
+         plain usx2y alsa mode is able to achieve 64frames, 4periods, but only at the
+         cost of easier triggered i.e. aeolus xruns (128 or 256frames,
+         2periods works but is useless cause of crackling).
+
+ This is a first "proof of concept" implementation.
+ Later, functionalities should migrate to more appropriate places:
+ Userland:
+ - The jackd could mmap its float-pcm buffers directly from alsa-lib.
+ - alsa-lib could provide power of 2 period sized shaping combined with int/float
+   conversation.
+   Currently the usx2y jack driver provides above 2 services.
+ Kernel:
+ - rawusb dma pcm buffer transport should go to snd-usb-lib, so also snd-usb-audio
+   devices can use it.
+   Currently rawusb dma pcm buffer transport (this file) is only available to snd-usb-usx2y.
+*/
+
+#include <linux/delay.h>
+#include <linux/gfp.h>
+#include "usbusx2yaudio.c"
+
+#if defined(USX2Y_NRPACKS_VARIABLE) || USX2Y_NRPACKS == 1
+
+#include <sound/hwdep.h>
+
+static int usx2y_usbpcm_urb_capt_retire(struct snd_usx2y_substream *subs)
+{
+	struct urb	*urb = subs->completed_urb;
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+	int		i, lens = 0, hwptr_done = subs->hwptr_done;
+	struct usx2ydev	*usx2y = subs->usx2y;
+	int head;
+
+	if (usx2y->hwdep_pcm_shm->capture_iso_start < 0) { //FIXME
+		head = usx2y->hwdep_pcm_shm->captured_iso_head + 1;
+		if (head >= ARRAY_SIZE(usx2y->hwdep_pcm_shm->captured_iso))
+			head = 0;
+		usx2y->hwdep_pcm_shm->capture_iso_start = head;
+		dev_dbg(&usx2y->dev->dev, "cap start %i\n", head);
+	}
+	for (i = 0; i < nr_of_packs(); i++) {
+		if (urb->iso_frame_desc[i].status) { /* active? hmm, skip this */
+			dev_err(&usx2y->dev->dev,
+				"active frame status %i. Most probably some hardware problem.\n",
+				urb->iso_frame_desc[i].status);
+			return urb->iso_frame_desc[i].status;
+		}
+		lens += urb->iso_frame_desc[i].actual_length / usx2y->stride;
+	}
+	hwptr_done += lens;
+	if (hwptr_done >= runtime->buffer_size)
+		hwptr_done -= runtime->buffer_size;
+	subs->hwptr_done = hwptr_done;
+	subs->transfer_done += lens;
+	/* update the pointer, call callback if necessary */
+	if (subs->transfer_done >= runtime->period_size) {
+		subs->transfer_done -= runtime->period_size;
+		snd_pcm_period_elapsed(subs->pcm_substream);
+	}
+	return 0;
+}
+
+static int usx2y_iso_frames_per_buffer(struct snd_pcm_runtime *runtime,
+					      struct usx2ydev *usx2y)
+{
+	return (runtime->buffer_size * 1000) / usx2y->rate + 1;	//FIXME: so far only correct period_size == 2^x ?
+}
+
+/*
+ * prepare urb for playback data pipe
+ *
+ * we copy the data directly from the pcm buffer.
+ * the current position to be copied is held in hwptr field.
+ * since a urb can handle only a single linear buffer, if the total
+ * transferred area overflows the buffer boundary, we cannot send
+ * it directly from the buffer.  thus the data is once copied to
+ * a temporary buffer and urb points to that.
+ */
+static int usx2y_hwdep_urb_play_prepare(struct snd_usx2y_substream *subs,
+					struct urb *urb)
+{
+	int count, counts, pack;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_hwdep_pcm_shm *shm = usx2y->hwdep_pcm_shm;
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+
+	if (shm->playback_iso_start < 0) {
+		shm->playback_iso_start = shm->captured_iso_head -
+			usx2y_iso_frames_per_buffer(runtime, usx2y);
+		if (shm->playback_iso_start < 0)
+			shm->playback_iso_start += ARRAY_SIZE(shm->captured_iso);
+		shm->playback_iso_head = shm->playback_iso_start;
+	}
+
+	count = 0;
+	for (pack = 0; pack < nr_of_packs(); pack++) {
+		/* calculate the size of a packet */
+		counts = shm->captured_iso[shm->playback_iso_head].length / usx2y->stride;
+		if (counts < 43 || counts > 50) {
+			dev_err(&usx2y->dev->dev, "should not be here with counts=%i\n", counts);
+			return -EPIPE;
+		}
+		/* set up descriptor */
+		urb->iso_frame_desc[pack].offset = shm->captured_iso[shm->playback_iso_head].offset;
+		urb->iso_frame_desc[pack].length = shm->captured_iso[shm->playback_iso_head].length;
+		if (atomic_read(&subs->state) != STATE_RUNNING)
+			memset((char *)urb->transfer_buffer + urb->iso_frame_desc[pack].offset, 0,
+			       urb->iso_frame_desc[pack].length);
+		if (++shm->playback_iso_head >= ARRAY_SIZE(shm->captured_iso))
+			shm->playback_iso_head = 0;
+		count += counts;
+	}
+	urb->transfer_buffer_length = count * usx2y->stride;
+	return 0;
+}
+
+static void usx2y_usbpcm_urb_capt_iso_advance(struct snd_usx2y_substream *subs,
+					      struct urb *urb)
+{
+	struct usb_iso_packet_descriptor *desc;
+	struct snd_usx2y_hwdep_pcm_shm *shm;
+	int pack, head;
+
+	for (pack = 0; pack < nr_of_packs(); ++pack) {
+		desc = urb->iso_frame_desc + pack;
+		if (subs) {
+			shm = subs->usx2y->hwdep_pcm_shm;
+			head = shm->captured_iso_head + 1;
+			if (head >= ARRAY_SIZE(shm->captured_iso))
+				head = 0;
+			shm->captured_iso[head].frame = urb->start_frame + pack;
+			shm->captured_iso[head].offset = desc->offset;
+			shm->captured_iso[head].length = desc->actual_length;
+			shm->captured_iso_head = head;
+			shm->captured_iso_frames++;
+		}
+		desc->offset += desc->length * NRURBS * nr_of_packs();
+		if (desc->offset + desc->length >= SSS)
+			desc->offset -= (SSS - desc->length);
+	}
+}
+
+static int usx2y_usbpcm_usbframe_complete(struct snd_usx2y_substream *capsubs,
+					  struct snd_usx2y_substream *capsubs2,
+					  struct snd_usx2y_substream *playbacksubs,
+					  int frame)
+{
+	int err, state;
+	struct urb *urb = playbacksubs->completed_urb;
+
+	state = atomic_read(&playbacksubs->state);
+	if (urb) {
+		if (state == STATE_RUNNING)
+			usx2y_urb_play_retire(playbacksubs, urb);
+		else if (state >= STATE_PRERUNNING)
+			atomic_inc(&playbacksubs->state);
+	} else {
+		switch (state) {
+		case STATE_STARTING1:
+			urb = playbacksubs->urb[0];
+			atomic_inc(&playbacksubs->state);
+			break;
+		case STATE_STARTING2:
+			urb = playbacksubs->urb[1];
+			atomic_inc(&playbacksubs->state);
+			break;
+		}
+	}
+	if (urb) {
+		err = usx2y_hwdep_urb_play_prepare(playbacksubs, urb);
+		if (err)
+			return err;
+		err = usx2y_hwdep_urb_play_prepare(playbacksubs, urb);
+		if (err)
+			return err;
+	}
+
+	playbacksubs->completed_urb = NULL;
+
+	state = atomic_read(&capsubs->state);
+	if (state >= STATE_PREPARED) {
+		if (state == STATE_RUNNING) {
+			err = usx2y_usbpcm_urb_capt_retire(capsubs);
+			if (err)
+				return err;
+		} else if (state >= STATE_PRERUNNING) {
+			atomic_inc(&capsubs->state);
+		}
+		usx2y_usbpcm_urb_capt_iso_advance(capsubs, capsubs->completed_urb);
+		if (capsubs2)
+			usx2y_usbpcm_urb_capt_iso_advance(NULL, capsubs2->completed_urb);
+		err = usx2y_urb_submit(capsubs, capsubs->completed_urb, frame);
+		if (err)
+			return err;
+		if (capsubs2) {
+			err = usx2y_urb_submit(capsubs2, capsubs2->completed_urb, frame);
+			if (err)
+				return err;
+		}
+	}
+	capsubs->completed_urb = NULL;
+	if (capsubs2)
+		capsubs2->completed_urb = NULL;
+	return 0;
+}
+
+static void i_usx2y_usbpcm_urb_complete(struct urb *urb)
+{
+	struct snd_usx2y_substream *subs = urb->context;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *capsubs, *capsubs2, *playbacksubs;
+
+	if (unlikely(atomic_read(&subs->state) < STATE_PREPARED)) {
+		dev_dbg(&usx2y->dev->dev,
+			"hcd_frame=%i ep=%i%s status=%i start_frame=%i\n",
+			usb_get_current_frame_number(usx2y->dev),
+			subs->endpoint, usb_pipein(urb->pipe) ? "in" : "out",
+			urb->status, urb->start_frame);
+		return;
+	}
+	if (unlikely(urb->status)) {
+		usx2y_error_urb_status(usx2y, subs, urb);
+		return;
+	}
+
+	subs->completed_urb = urb;
+	capsubs = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+	capsubs2 = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
+	playbacksubs = usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+	if (capsubs->completed_urb && atomic_read(&capsubs->state) >= STATE_PREPARED &&
+	    (!capsubs2 || capsubs2->completed_urb) &&
+	    (playbacksubs->completed_urb || atomic_read(&playbacksubs->state) < STATE_PREPARED)) {
+		if (!usx2y_usbpcm_usbframe_complete(capsubs, capsubs2, playbacksubs, urb->start_frame)) {
+			usx2y->wait_iso_frame += nr_of_packs();
+		} else {
+			usx2y_clients_stop(usx2y);
+		}
+	}
+}
+
+static void usx2y_hwdep_urb_release(struct urb **urb)
+{
+	usb_kill_urb(*urb);
+	usb_free_urb(*urb);
+	*urb = NULL;
+}
+
+/*
+ * release a substream
+ */
+static void usx2y_usbpcm_urbs_release(struct snd_usx2y_substream *subs)
+{
+	int i;
+
+	dev_dbg(&subs->usx2y->dev->dev,
+		"snd_usx2y_urbs_release() %i\n", subs->endpoint);
+	for (i = 0; i < NRURBS; i++)
+		usx2y_hwdep_urb_release(subs->urb + i);
+}
+
+static void usx2y_usbpcm_subs_startup_finish(struct usx2ydev *usx2y)
+{
+	usx2y_urbs_set_complete(usx2y, i_usx2y_usbpcm_urb_complete);
+	usx2y->prepare_subs = NULL;
+}
+
+static void i_usx2y_usbpcm_subs_startup(struct urb *urb)
+{
+	struct snd_usx2y_substream *subs = urb->context;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *prepare_subs = usx2y->prepare_subs;
+	struct snd_usx2y_substream *cap_subs2;
+
+	if (prepare_subs &&
+	    urb->start_frame == prepare_subs->urb[0]->start_frame) {
+		atomic_inc(&prepare_subs->state);
+		if (prepare_subs == usx2y->subs[SNDRV_PCM_STREAM_CAPTURE]) {
+			cap_subs2 = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
+			if (cap_subs2)
+				atomic_inc(&cap_subs2->state);
+		}
+		usx2y_usbpcm_subs_startup_finish(usx2y);
+		wake_up(&usx2y->prepare_wait_queue);
+	}
+
+	i_usx2y_usbpcm_urb_complete(urb);
+}
+
+/*
+ * initialize a substream's urbs
+ */
+static int usx2y_usbpcm_urbs_allocate(struct snd_usx2y_substream *subs)
+{
+	int i;
+	unsigned int pipe;
+	int is_playback = subs == subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+	struct usb_device *dev = subs->usx2y->dev;
+	struct urb **purb;
+
+	pipe = is_playback ? usb_sndisocpipe(dev, subs->endpoint) :
+			usb_rcvisocpipe(dev, subs->endpoint);
+	subs->maxpacksize = usb_maxpacket(dev, pipe);
+	if (!subs->maxpacksize)
+		return -EINVAL;
+
+	/* allocate and initialize data urbs */
+	for (i = 0; i < NRURBS; i++) {
+		purb = subs->urb + i;
+		if (*purb) {
+			usb_kill_urb(*purb);
+			continue;
+		}
+		*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
+		if (!*purb) {
+			usx2y_usbpcm_urbs_release(subs);
+			return -ENOMEM;
+		}
+		(*purb)->transfer_buffer = is_playback ?
+			subs->usx2y->hwdep_pcm_shm->playback : (
+				subs->endpoint == 0x8 ?
+				subs->usx2y->hwdep_pcm_shm->capture0x8 :
+				subs->usx2y->hwdep_pcm_shm->capture0xA);
+
+		(*purb)->dev = dev;
+		(*purb)->pipe = pipe;
+		(*purb)->number_of_packets = nr_of_packs();
+		(*purb)->context = subs;
+		(*purb)->interval = 1;
+		(*purb)->complete = i_usx2y_usbpcm_subs_startup;
+	}
+	return 0;
+}
+
+/*
+ * free the buffer
+ */
+static int snd_usx2y_usbpcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+	struct snd_usx2y_substream *cap_subs;
+	struct snd_usx2y_substream *playback_subs;
+	struct snd_usx2y_substream *cap_subs2;
+
+	guard(mutex)(&subs->usx2y->pcm_mutex);
+	dev_dbg(&subs->usx2y->dev->dev, "%s(%p)\n", __func__, substream);
+
+	cap_subs2 = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		cap_subs = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+		atomic_set(&subs->state, STATE_STOPPED);
+		usx2y_usbpcm_urbs_release(subs);
+		if (!cap_subs->pcm_substream ||
+		    !cap_subs->pcm_substream->runtime ||
+		    cap_subs->pcm_substream->runtime->state < SNDRV_PCM_STATE_PREPARED) {
+			atomic_set(&cap_subs->state, STATE_STOPPED);
+			if (cap_subs2)
+				atomic_set(&cap_subs2->state, STATE_STOPPED);
+			usx2y_usbpcm_urbs_release(cap_subs);
+			if (cap_subs2)
+				usx2y_usbpcm_urbs_release(cap_subs2);
+		}
+	} else {
+		playback_subs = subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+		if (atomic_read(&playback_subs->state) < STATE_PREPARED) {
+			atomic_set(&subs->state, STATE_STOPPED);
+			if (cap_subs2)
+				atomic_set(&cap_subs2->state, STATE_STOPPED);
+			usx2y_usbpcm_urbs_release(subs);
+			if (cap_subs2)
+				usx2y_usbpcm_urbs_release(cap_subs2);
+		}
+	}
+	return 0;
+}
+
+static void usx2y_usbpcm_subs_startup(struct snd_usx2y_substream *subs)
+{
+	struct usx2ydev *usx2y = subs->usx2y;
+
+	usx2y->prepare_subs = subs;
+	subs->urb[0]->start_frame = -1;
+	smp_wmb();	// Make sure above modifications are seen by i_usx2y_subs_startup()
+	usx2y_urbs_set_complete(usx2y, i_usx2y_usbpcm_subs_startup);
+}
+
+static int usx2y_usbpcm_urbs_start(struct snd_usx2y_substream *subs)
+{
+	int	p, u, err, stream = subs->pcm_substream->stream;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct urb *urb;
+	unsigned long pack;
+
+	if (stream == SNDRV_PCM_STREAM_CAPTURE) {
+		usx2y->hwdep_pcm_shm->captured_iso_head = -1;
+		usx2y->hwdep_pcm_shm->captured_iso_frames = 0;
+	}
+
+	for (p = 0; 3 >= (stream + p); p += 2) {
+		struct snd_usx2y_substream *subs = usx2y->subs[stream + p];
+		if (subs) {
+			err = usx2y_usbpcm_urbs_allocate(subs);
+			if (err < 0)
+				return err;
+			subs->completed_urb = NULL;
+		}
+	}
+
+	for (p = 0; p < 4; p++) {
+		struct snd_usx2y_substream *subs = usx2y->subs[p];
+
+		if (subs && atomic_read(&subs->state) >= STATE_PREPARED)
+			goto start;
+	}
+
+ start:
+	usx2y_usbpcm_subs_startup(subs);
+	for (u = 0; u < NRURBS; u++) {
+		for (p = 0; 3 >= (stream + p); p += 2) {
+			struct snd_usx2y_substream *subs = usx2y->subs[stream + p];
+
+			if (!subs)
+				continue;
+			urb = subs->urb[u];
+			if (usb_pipein(urb->pipe)) {
+				if (!u)
+					atomic_set(&subs->state, STATE_STARTING3);
+				urb->dev = usx2y->dev;
+				for (pack = 0; pack < nr_of_packs(); pack++) {
+					urb->iso_frame_desc[pack].offset = subs->maxpacksize * (pack + u * nr_of_packs());
+					urb->iso_frame_desc[pack].length = subs->maxpacksize;
+				}
+				urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs();
+				err = usb_submit_urb(urb, GFP_KERNEL);
+				if (err < 0) {
+					dev_err(&urb->dev->dev,
+						"cannot usb_submit_urb() for urb %d, err = %d\n",
+						u, err);
+					err = -EPIPE;
+					goto cleanup;
+				}  else {
+					if (!u)
+						usx2y->wait_iso_frame = urb->start_frame;
+				}
+				urb->transfer_flags = 0;
+			} else {
+				atomic_set(&subs->state, STATE_STARTING1);
+				break;
+			}
+		}
+	}
+	err = 0;
+	wait_event(usx2y->prepare_wait_queue, !usx2y->prepare_subs);
+	if (atomic_read(&subs->state) != STATE_PREPARED)
+		err = -EPIPE;
+
+ cleanup:
+	if (err) {
+		usx2y_subs_startup_finish(usx2y);	// Call it now
+		usx2y_clients_stop(usx2y);	// something is completely wrong > stop everything
+	}
+	return err;
+}
+
+#define USX2Y_HWDEP_PCM_PAGES	\
+	PAGE_ALIGN(sizeof(struct snd_usx2y_hwdep_pcm_shm))
+
+/*
+ * prepare callback
+ *
+ * set format and initialize urbs
+ */
+static int snd_usx2y_usbpcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *capsubs = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+	int err = 0;
+
+	dev_dbg(&usx2y->dev->dev, "snd_usx2y_pcm_prepare(%p)\n", substream);
+
+	guard(mutex)(&usx2y->pcm_mutex);
+
+	if (!usx2y->hwdep_pcm_shm) {
+		usx2y->hwdep_pcm_shm = alloc_pages_exact(USX2Y_HWDEP_PCM_PAGES,
+							 GFP_KERNEL);
+		if (!usx2y->hwdep_pcm_shm)
+			return -ENOMEM;
+		memset(usx2y->hwdep_pcm_shm, 0, USX2Y_HWDEP_PCM_PAGES);
+	}
+
+	usx2y_subs_prepare(subs);
+	// Start hardware streams
+	// SyncStream first....
+	if (atomic_read(&capsubs->state) < STATE_PREPARED) {
+		if (usx2y->format != runtime->format) {
+			err = usx2y_format_set(usx2y, runtime->format);
+			if (err < 0)
+				return err;
+		}
+		if (usx2y->rate != runtime->rate) {
+			err = usx2y_rate_set(usx2y, runtime->rate);
+			if (err < 0)
+				return err;
+		}
+		dev_dbg(&usx2y->dev->dev,
+			"starting capture pipe for %s\n", subs == capsubs ?
+			"self" : "playpipe");
+		err = usx2y_usbpcm_urbs_start(capsubs);
+		if (err < 0)
+			return err;
+	}
+
+	if (subs != capsubs) {
+		usx2y->hwdep_pcm_shm->playback_iso_start = -1;
+		if (atomic_read(&subs->state) < STATE_PREPARED) {
+			while (usx2y_iso_frames_per_buffer(runtime, usx2y) >
+			       usx2y->hwdep_pcm_shm->captured_iso_frames) {
+				dev_dbg(&usx2y->dev->dev,
+					"Wait: iso_frames_per_buffer=%i,captured_iso_frames=%i\n",
+					usx2y_iso_frames_per_buffer(runtime, usx2y),
+					usx2y->hwdep_pcm_shm->captured_iso_frames);
+				if (msleep_interruptible(10))
+					return -ERESTARTSYS;
+			}
+			err = usx2y_usbpcm_urbs_start(subs);
+			if (err < 0)
+				return err;
+		}
+		dev_dbg(&usx2y->dev->dev,
+			"Ready: iso_frames_per_buffer=%i,captured_iso_frames=%i\n",
+			usx2y_iso_frames_per_buffer(runtime, usx2y),
+			usx2y->hwdep_pcm_shm->captured_iso_frames);
+	} else {
+		usx2y->hwdep_pcm_shm->capture_iso_start = -1;
+	}
+
+	return err;
+}
+
+static const struct snd_pcm_hardware snd_usx2y_4c = {
+	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
+				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				 SNDRV_PCM_INFO_MMAP_VALID),
+	.formats =                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
+	.rates =                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
+	.rate_min =                44100,
+	.rate_max =                48000,
+	.channels_min =            2,
+	.channels_max =            4,
+	.buffer_bytes_max =	(2*128*1024),
+	.period_bytes_min =	64,
+	.period_bytes_max =	(128*1024),
+	.periods_min =		2,
+	.periods_max =		1024,
+	.fifo_size =              0
+};
+
+static int snd_usx2y_usbpcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_usx2y_substream	*subs =
+		((struct snd_usx2y_substream **)
+		 snd_pcm_substream_chip(substream))[substream->stream];
+	struct snd_pcm_runtime	*runtime = substream->runtime;
+
+	if (!(subs->usx2y->chip_status & USX2Y_STAT_CHIP_MMAP_PCM_URBS))
+		return -EBUSY;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		runtime->hw = snd_usx2y_2c;
+	else
+		runtime->hw = (subs->usx2y->subs[3] ? snd_usx2y_4c : snd_usx2y_2c);
+	runtime->private_data = subs;
+	subs->pcm_substream = substream;
+	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 1000, 200000);
+	return 0;
+}
+
+static int snd_usx2y_usbpcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+
+	subs->pcm_substream = NULL;
+	return 0;
+}
+
+static const struct snd_pcm_ops snd_usx2y_usbpcm_ops = {
+	.open =		snd_usx2y_usbpcm_open,
+	.close =	snd_usx2y_usbpcm_close,
+	.hw_params =	snd_usx2y_pcm_hw_params,
+	.hw_free =	snd_usx2y_usbpcm_hw_free,
+	.prepare =	snd_usx2y_usbpcm_prepare,
+	.trigger =	snd_usx2y_pcm_trigger,
+	.pointer =	snd_usx2y_pcm_pointer,
+};
+
+static int usx2y_pcms_busy_check(struct snd_card *card)
+{
+	struct usx2ydev	*dev = usx2y(card);
+	struct snd_usx2y_substream *subs;
+	int i;
+
+	for (i = 0; i < dev->pcm_devs * 2; i++) {
+		subs = dev->subs[i];
+		if (subs && subs->pcm_substream &&
+		    SUBSTREAM_BUSY(subs->pcm_substream))
+			return -EBUSY;
+	}
+	return 0;
+}
+
+static int snd_usx2y_hwdep_pcm_open(struct snd_hwdep *hw, struct file *file)
+{
+	struct snd_card *card = hw->card;
+	int err;
+
+	guard(mutex)(&usx2y(card)->pcm_mutex);
+	err = usx2y_pcms_busy_check(card);
+	if (!err)
+		usx2y(card)->chip_status |= USX2Y_STAT_CHIP_MMAP_PCM_URBS;
+	return err;
+}
+
+static int snd_usx2y_hwdep_pcm_release(struct snd_hwdep *hw, struct file *file)
+{
+	struct snd_card *card = hw->card;
+	int err;
+
+	guard(mutex)(&usx2y(card)->pcm_mutex);
+	err = usx2y_pcms_busy_check(card);
+	if (!err)
+		usx2y(hw->card)->chip_status &= ~USX2Y_STAT_CHIP_MMAP_PCM_URBS;
+	return err;
+}
+
+static void snd_usx2y_hwdep_pcm_vm_open(struct vm_area_struct *area)
+{
+}
+
+static void snd_usx2y_hwdep_pcm_vm_close(struct vm_area_struct *area)
+{
+}
+
+static vm_fault_t snd_usx2y_hwdep_pcm_vm_fault(struct vm_fault *vmf)
+{
+	unsigned long offset;
+	void *vaddr;
+
+	offset = vmf->pgoff << PAGE_SHIFT;
+	if (offset >= USX2Y_HWDEP_PCM_PAGES)
+		return VM_FAULT_SIGBUS;
+	vaddr = (char *)((struct usx2ydev *)vmf->vma->vm_private_data)->hwdep_pcm_shm + offset;
+	vmf->page = virt_to_page(vaddr);
+	get_page(vmf->page);
+	return 0;
+}
+
+static const struct vm_operations_struct snd_usx2y_hwdep_pcm_vm_ops = {
+	.open = snd_usx2y_hwdep_pcm_vm_open,
+	.close = snd_usx2y_hwdep_pcm_vm_close,
+	.fault = snd_usx2y_hwdep_pcm_vm_fault,
+};
+
+static int snd_usx2y_hwdep_pcm_mmap(struct snd_hwdep *hw, struct file *filp, struct vm_area_struct *area)
+{
+	unsigned long	size = (unsigned long)(area->vm_end - area->vm_start);
+	struct usx2ydev	*usx2y = hw->private_data;
+
+	if (!(usx2y->chip_status & USX2Y_STAT_CHIP_INIT))
+		return -EBUSY;
+
+	/* if userspace tries to mmap beyond end of our buffer, fail */
+	if (size > USX2Y_HWDEP_PCM_PAGES) {
+		dev_dbg(hw->card->dev, "%s: %lu > %lu\n", __func__,
+			size, (unsigned long)USX2Y_HWDEP_PCM_PAGES);
+		return -EINVAL;
+	}
+
+	if (!usx2y->hwdep_pcm_shm)
+		return -ENODEV;
+
+	area->vm_ops = &snd_usx2y_hwdep_pcm_vm_ops;
+	vm_flags_set(area, VM_DONTEXPAND | VM_DONTDUMP);
+	area->vm_private_data = hw->private_data;
+	return 0;
+}
+
+static void snd_usx2y_hwdep_pcm_private_free(struct snd_hwdep *hwdep)
+{
+	struct usx2ydev *usx2y = hwdep->private_data;
+
+	if (usx2y->hwdep_pcm_shm)
+		free_pages_exact(usx2y->hwdep_pcm_shm, USX2Y_HWDEP_PCM_PAGES);
+}
+
+int usx2y_hwdep_pcm_new(struct snd_card *card)
+{
+	int err;
+	struct snd_hwdep *hw;
+	struct snd_pcm *pcm;
+	struct usb_device *dev = usx2y(card)->dev;
+
+	if (nr_of_packs() != 1)
+		return 0;
+
+	err = snd_hwdep_new(card, SND_USX2Y_USBPCM_ID, 1, &hw);
+	if (err < 0)
+		return err;
+
+	hw->iface = SNDRV_HWDEP_IFACE_USX2Y_PCM;
+	hw->private_data = usx2y(card);
+	hw->private_free = snd_usx2y_hwdep_pcm_private_free;
+	hw->ops.open = snd_usx2y_hwdep_pcm_open;
+	hw->ops.release = snd_usx2y_hwdep_pcm_release;
+	hw->ops.mmap = snd_usx2y_hwdep_pcm_mmap;
+	hw->exclusive = 1;
+	sprintf(hw->name, "/dev/bus/usb/%03d/%03d/hwdeppcm", dev->bus->busnum, dev->devnum);
+
+	err = snd_pcm_new(card, NAME_ALLCAPS" hwdep Audio", 2, 1, 1, &pcm);
+	if (err < 0)
+		return err;
+
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_usx2y_usbpcm_ops);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_usx2y_usbpcm_ops);
+
+	pcm->private_data = usx2y(card)->subs;
+	pcm->info_flags = 0;
+
+	sprintf(pcm->name, NAME_ALLCAPS" hwdep Audio");
+	snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream,
+				   SNDRV_DMA_TYPE_CONTINUOUS,
+				   NULL,
+				   64*1024, 128*1024);
+	snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
+				   SNDRV_DMA_TYPE_CONTINUOUS,
+				   NULL,
+				   64*1024, 128*1024);
+
+	return 0;
+}
+
+#else
+
+int usx2y_hwdep_pcm_new(struct snd_card *card)
+{
+	return 0;
+}
+
+#endif
diff --git a/sound/usb/usx2y/usx2yhwdeppcm.h b/sound/usb/usx2y/usx2yhwdeppcm.h
new file mode 100644
index 000000000..731b1c5a3
--- /dev/null
+++ b/sound/usb/usx2y/usx2yhwdeppcm.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#define MAXPACK 50
+#define MAXBUFFERMS 100
+#define MAXSTRIDE 3
+
+#define SSS (((MAXPACK*MAXBUFFERMS*MAXSTRIDE + 4096) / 4096) * 4096)
+struct snd_usx2y_hwdep_pcm_shm {
+	char playback[SSS];
+	char capture0x8[SSS];
+	char capture0xA[SSS];
+	volatile int playback_iso_head;
+	int playback_iso_start;
+	struct {
+		int	frame,
+			offset,
+			length;
+	} captured_iso[128];
+	volatile int captured_iso_head;
+	volatile unsigned captured_iso_frames;
+	int capture_iso_start;
+};
+
+int usx2y_hwdep_pcm_new(struct snd_card *card);